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Linux/fs/ext4/ext4.h

  1 /*
  2  *  ext4.h
  3  *
  4  * Copyright (C) 1992, 1993, 1994, 1995
  5  * Remy Card (card@masi.ibp.fr)
  6  * Laboratoire MASI - Institut Blaise Pascal
  7  * Universite Pierre et Marie Curie (Paris VI)
  8  *
  9  *  from
 10  *
 11  *  linux/include/linux/minix_fs.h
 12  *
 13  *  Copyright (C) 1991, 1992  Linus Torvalds
 14  */
 15 
 16 #ifndef _EXT4_H
 17 #define _EXT4_H
 18 
 19 #include <linux/types.h>
 20 #include <linux/blkdev.h>
 21 #include <linux/magic.h>
 22 #include <linux/jbd2.h>
 23 #include <linux/quota.h>
 24 #include <linux/rwsem.h>
 25 #include <linux/rbtree.h>
 26 #include <linux/seqlock.h>
 27 #include <linux/mutex.h>
 28 #include <linux/timer.h>
 29 #include <linux/version.h>
 30 #include <linux/wait.h>
 31 #include <linux/blockgroup_lock.h>
 32 #include <linux/percpu_counter.h>
 33 #include <linux/ratelimit.h>
 34 #include <crypto/hash.h>
 35 #include <linux/fscrypto.h>
 36 #include <linux/falloc.h>
 37 #include <linux/percpu-rwsem.h>
 38 #ifdef __KERNEL__
 39 #include <linux/compat.h>
 40 #endif
 41 
 42 /*
 43  * The fourth extended filesystem constants/structures
 44  */
 45 
 46 /*
 47  * with AGGRESSIVE_CHECK allocator runs consistency checks over
 48  * structures. these checks slow things down a lot
 49  */
 50 #define AGGRESSIVE_CHECK__
 51 
 52 /*
 53  * with DOUBLE_CHECK defined mballoc creates persistent in-core
 54  * bitmaps, maintains and uses them to check for double allocations
 55  */
 56 #define DOUBLE_CHECK__
 57 
 58 /*
 59  * Define EXT4FS_DEBUG to produce debug messages
 60  */
 61 #undef EXT4FS_DEBUG
 62 
 63 /*
 64  * Debug code
 65  */
 66 #ifdef EXT4FS_DEBUG
 67 #define ext4_debug(f, a...)                                             \
 68         do {                                                            \
 69                 printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",        \
 70                         __FILE__, __LINE__, __func__);                  \
 71                 printk(KERN_DEBUG f, ## a);                             \
 72         } while (0)
 73 #else
 74 #define ext4_debug(fmt, ...)    no_printk(fmt, ##__VA_ARGS__)
 75 #endif
 76 
 77 /*
 78  * Turn on EXT_DEBUG to get lots of info about extents operations.
 79  */
 80 #define EXT_DEBUG__
 81 #ifdef EXT_DEBUG
 82 #define ext_debug(fmt, ...)     printk(fmt, ##__VA_ARGS__)
 83 #else
 84 #define ext_debug(fmt, ...)     no_printk(fmt, ##__VA_ARGS__)
 85 #endif
 86 
 87 /* data type for block offset of block group */
 88 typedef int ext4_grpblk_t;
 89 
 90 /* data type for filesystem-wide blocks number */
 91 typedef unsigned long long ext4_fsblk_t;
 92 
 93 /* data type for file logical block number */
 94 typedef __u32 ext4_lblk_t;
 95 
 96 /* data type for block group number */
 97 typedef unsigned int ext4_group_t;
 98 
 99 enum SHIFT_DIRECTION {
100         SHIFT_LEFT = 0,
101         SHIFT_RIGHT,
102 };
103 
104 /*
105  * Flags used in mballoc's allocation_context flags field.
106  *
107  * Also used to show what's going on for debugging purposes when the
108  * flag field is exported via the traceport interface
109  */
110 
111 /* prefer goal again. length */
112 #define EXT4_MB_HINT_MERGE              0x0001
113 /* blocks already reserved */
114 #define EXT4_MB_HINT_RESERVED           0x0002
115 /* metadata is being allocated */
116 #define EXT4_MB_HINT_METADATA           0x0004
117 /* first blocks in the file */
118 #define EXT4_MB_HINT_FIRST              0x0008
119 /* search for the best chunk */
120 #define EXT4_MB_HINT_BEST               0x0010
121 /* data is being allocated */
122 #define EXT4_MB_HINT_DATA               0x0020
123 /* don't preallocate (for tails) */
124 #define EXT4_MB_HINT_NOPREALLOC         0x0040
125 /* allocate for locality group */
126 #define EXT4_MB_HINT_GROUP_ALLOC        0x0080
127 /* allocate goal blocks or none */
128 #define EXT4_MB_HINT_GOAL_ONLY          0x0100
129 /* goal is meaningful */
130 #define EXT4_MB_HINT_TRY_GOAL           0x0200
131 /* blocks already pre-reserved by delayed allocation */
132 #define EXT4_MB_DELALLOC_RESERVED       0x0400
133 /* We are doing stream allocation */
134 #define EXT4_MB_STREAM_ALLOC            0x0800
135 /* Use reserved root blocks if needed */
136 #define EXT4_MB_USE_ROOT_BLOCKS         0x1000
137 /* Use blocks from reserved pool */
138 #define EXT4_MB_USE_RESERVED            0x2000
139 
140 struct ext4_allocation_request {
141         /* target inode for block we're allocating */
142         struct inode *inode;
143         /* how many blocks we want to allocate */
144         unsigned int len;
145         /* logical block in target inode */
146         ext4_lblk_t logical;
147         /* the closest logical allocated block to the left */
148         ext4_lblk_t lleft;
149         /* the closest logical allocated block to the right */
150         ext4_lblk_t lright;
151         /* phys. target (a hint) */
152         ext4_fsblk_t goal;
153         /* phys. block for the closest logical allocated block to the left */
154         ext4_fsblk_t pleft;
155         /* phys. block for the closest logical allocated block to the right */
156         ext4_fsblk_t pright;
157         /* flags. see above EXT4_MB_HINT_* */
158         unsigned int flags;
159 };
160 
161 /*
162  * Logical to physical block mapping, used by ext4_map_blocks()
163  *
164  * This structure is used to pass requests into ext4_map_blocks() as
165  * well as to store the information returned by ext4_map_blocks().  It
166  * takes less room on the stack than a struct buffer_head.
167  */
168 #define EXT4_MAP_NEW            (1 << BH_New)
169 #define EXT4_MAP_MAPPED         (1 << BH_Mapped)
170 #define EXT4_MAP_UNWRITTEN      (1 << BH_Unwritten)
171 #define EXT4_MAP_BOUNDARY       (1 << BH_Boundary)
172 #define EXT4_MAP_FLAGS          (EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
173                                  EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY)
174 
175 struct ext4_map_blocks {
176         ext4_fsblk_t m_pblk;
177         ext4_lblk_t m_lblk;
178         unsigned int m_len;
179         unsigned int m_flags;
180 };
181 
182 /*
183  * Flags for ext4_io_end->flags
184  */
185 #define EXT4_IO_END_UNWRITTEN   0x0001
186 
187 /*
188  * For converting unwritten extents on a work queue. 'handle' is used for
189  * buffered writeback.
190  */
191 typedef struct ext4_io_end {
192         struct list_head        list;           /* per-file finished IO list */
193         handle_t                *handle;        /* handle reserved for extent
194                                                  * conversion */
195         struct inode            *inode;         /* file being written to */
196         struct bio              *bio;           /* Linked list of completed
197                                                  * bios covering the extent */
198         unsigned int            flag;           /* unwritten or not */
199         atomic_t                count;          /* reference counter */
200         loff_t                  offset;         /* offset in the file */
201         ssize_t                 size;           /* size of the extent */
202 } ext4_io_end_t;
203 
204 struct ext4_io_submit {
205         struct writeback_control *io_wbc;
206         struct bio              *io_bio;
207         ext4_io_end_t           *io_end;
208         sector_t                io_next_block;
209 };
210 
211 /*
212  * Special inodes numbers
213  */
214 #define EXT4_BAD_INO             1      /* Bad blocks inode */
215 #define EXT4_ROOT_INO            2      /* Root inode */
216 #define EXT4_USR_QUOTA_INO       3      /* User quota inode */
217 #define EXT4_GRP_QUOTA_INO       4      /* Group quota inode */
218 #define EXT4_BOOT_LOADER_INO     5      /* Boot loader inode */
219 #define EXT4_UNDEL_DIR_INO       6      /* Undelete directory inode */
220 #define EXT4_RESIZE_INO          7      /* Reserved group descriptors inode */
221 #define EXT4_JOURNAL_INO         8      /* Journal inode */
222 
223 /* First non-reserved inode for old ext4 filesystems */
224 #define EXT4_GOOD_OLD_FIRST_INO 11
225 
226 /*
227  * Maximal count of links to a file
228  */
229 #define EXT4_LINK_MAX           65000
230 
231 /*
232  * Macro-instructions used to manage several block sizes
233  */
234 #define EXT4_MIN_BLOCK_SIZE             1024
235 #define EXT4_MAX_BLOCK_SIZE             65536
236 #define EXT4_MIN_BLOCK_LOG_SIZE         10
237 #define EXT4_MAX_BLOCK_LOG_SIZE         16
238 #define EXT4_MAX_CLUSTER_LOG_SIZE       30
239 #ifdef __KERNEL__
240 # define EXT4_BLOCK_SIZE(s)             ((s)->s_blocksize)
241 #else
242 # define EXT4_BLOCK_SIZE(s)             (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
243 #endif
244 #define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof(__u32))
245 #define EXT4_CLUSTER_SIZE(s)            (EXT4_BLOCK_SIZE(s) << \
246                                          EXT4_SB(s)->s_cluster_bits)
247 #ifdef __KERNEL__
248 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
249 # define EXT4_CLUSTER_BITS(s)           (EXT4_SB(s)->s_cluster_bits)
250 #else
251 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
252 #endif
253 #ifdef __KERNEL__
254 #define EXT4_ADDR_PER_BLOCK_BITS(s)     (EXT4_SB(s)->s_addr_per_block_bits)
255 #define EXT4_INODE_SIZE(s)              (EXT4_SB(s)->s_inode_size)
256 #define EXT4_FIRST_INO(s)               (EXT4_SB(s)->s_first_ino)
257 #else
258 #define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
259                                  EXT4_GOOD_OLD_INODE_SIZE : \
260                                  (s)->s_inode_size)
261 #define EXT4_FIRST_INO(s)       (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
262                                  EXT4_GOOD_OLD_FIRST_INO : \
263                                  (s)->s_first_ino)
264 #endif
265 #define EXT4_BLOCK_ALIGN(size, blkbits)         ALIGN((size), (1 << (blkbits)))
266 #define EXT4_MAX_BLOCKS(size, offset, blkbits) \
267         ((EXT4_BLOCK_ALIGN(size + offset, blkbits) >> blkbits) - (offset >> \
268                                                                   blkbits))
269 
270 /* Translate a block number to a cluster number */
271 #define EXT4_B2C(sbi, blk)      ((blk) >> (sbi)->s_cluster_bits)
272 /* Translate a cluster number to a block number */
273 #define EXT4_C2B(sbi, cluster)  ((cluster) << (sbi)->s_cluster_bits)
274 /* Translate # of blks to # of clusters */
275 #define EXT4_NUM_B2C(sbi, blks) (((blks) + (sbi)->s_cluster_ratio - 1) >> \
276                                  (sbi)->s_cluster_bits)
277 /* Mask out the low bits to get the starting block of the cluster */
278 #define EXT4_PBLK_CMASK(s, pblk) ((pblk) &                              \
279                                   ~((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
280 #define EXT4_LBLK_CMASK(s, lblk) ((lblk) &                              \
281                                   ~((ext4_lblk_t) (s)->s_cluster_ratio - 1))
282 /* Get the cluster offset */
283 #define EXT4_PBLK_COFF(s, pblk) ((pblk) &                               \
284                                  ((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
285 #define EXT4_LBLK_COFF(s, lblk) ((lblk) &                               \
286                                  ((ext4_lblk_t) (s)->s_cluster_ratio - 1))
287 
288 /*
289  * Structure of a blocks group descriptor
290  */
291 struct ext4_group_desc
292 {
293         __le32  bg_block_bitmap_lo;     /* Blocks bitmap block */
294         __le32  bg_inode_bitmap_lo;     /* Inodes bitmap block */
295         __le32  bg_inode_table_lo;      /* Inodes table block */
296         __le16  bg_free_blocks_count_lo;/* Free blocks count */
297         __le16  bg_free_inodes_count_lo;/* Free inodes count */
298         __le16  bg_used_dirs_count_lo;  /* Directories count */
299         __le16  bg_flags;               /* EXT4_BG_flags (INODE_UNINIT, etc) */
300         __le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
301         __le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
302         __le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
303         __le16  bg_itable_unused_lo;    /* Unused inodes count */
304         __le16  bg_checksum;            /* crc16(sb_uuid+group+desc) */
305         __le32  bg_block_bitmap_hi;     /* Blocks bitmap block MSB */
306         __le32  bg_inode_bitmap_hi;     /* Inodes bitmap block MSB */
307         __le32  bg_inode_table_hi;      /* Inodes table block MSB */
308         __le16  bg_free_blocks_count_hi;/* Free blocks count MSB */
309         __le16  bg_free_inodes_count_hi;/* Free inodes count MSB */
310         __le16  bg_used_dirs_count_hi;  /* Directories count MSB */
311         __le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
312         __le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
313         __le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
314         __le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
315         __u32   bg_reserved;
316 };
317 
318 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END        \
319         (offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
320          sizeof(__le16))
321 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END        \
322         (offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
323          sizeof(__le16))
324 
325 /*
326  * Structure of a flex block group info
327  */
328 
329 struct flex_groups {
330         atomic64_t      free_clusters;
331         atomic_t        free_inodes;
332         atomic_t        used_dirs;
333 };
334 
335 #define EXT4_BG_INODE_UNINIT    0x0001 /* Inode table/bitmap not in use */
336 #define EXT4_BG_BLOCK_UNINIT    0x0002 /* Block bitmap not in use */
337 #define EXT4_BG_INODE_ZEROED    0x0004 /* On-disk itable initialized to zero */
338 
339 /*
340  * Macro-instructions used to manage group descriptors
341  */
342 #define EXT4_MIN_DESC_SIZE              32
343 #define EXT4_MIN_DESC_SIZE_64BIT        64
344 #define EXT4_MAX_DESC_SIZE              EXT4_MIN_BLOCK_SIZE
345 #define EXT4_DESC_SIZE(s)               (EXT4_SB(s)->s_desc_size)
346 #ifdef __KERNEL__
347 # define EXT4_BLOCKS_PER_GROUP(s)       (EXT4_SB(s)->s_blocks_per_group)
348 # define EXT4_CLUSTERS_PER_GROUP(s)     (EXT4_SB(s)->s_clusters_per_group)
349 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_SB(s)->s_desc_per_block)
350 # define EXT4_INODES_PER_GROUP(s)       (EXT4_SB(s)->s_inodes_per_group)
351 # define EXT4_DESC_PER_BLOCK_BITS(s)    (EXT4_SB(s)->s_desc_per_block_bits)
352 #else
353 # define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
354 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
355 # define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
356 #endif
357 
358 /*
359  * Constants relative to the data blocks
360  */
361 #define EXT4_NDIR_BLOCKS                12
362 #define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
363 #define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
364 #define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
365 #define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
366 
367 /*
368  * Inode flags
369  */
370 #define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
371 #define EXT4_UNRM_FL                    0x00000002 /* Undelete */
372 #define EXT4_COMPR_FL                   0x00000004 /* Compress file */
373 #define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
374 #define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
375 #define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
376 #define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
377 #define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
378 /* Reserved for compression usage... */
379 #define EXT4_DIRTY_FL                   0x00000100
380 #define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
381 #define EXT4_NOCOMPR_FL                 0x00000400 /* Don't compress */
382         /* nb: was previously EXT2_ECOMPR_FL */
383 #define EXT4_ENCRYPT_FL                 0x00000800 /* encrypted file */
384 /* End compression flags --- maybe not all used */
385 #define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
386 #define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
387 #define EXT4_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
388 #define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
389 #define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
390 #define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
391 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
392 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
393 #define EXT4_EA_INODE_FL                0x00200000 /* Inode used for large EA */
394 #define EXT4_EOFBLOCKS_FL               0x00400000 /* Blocks allocated beyond EOF */
395 #define EXT4_INLINE_DATA_FL             0x10000000 /* Inode has inline data. */
396 #define EXT4_PROJINHERIT_FL             0x20000000 /* Create with parents projid */
397 #define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
398 
399 #define EXT4_FL_USER_VISIBLE            0x304BDFFF /* User visible flags */
400 #define EXT4_FL_USER_MODIFIABLE         0x204BC0FF /* User modifiable flags */
401 
402 /* Flags we can manipulate with through EXT4_IOC_FSSETXATTR */
403 #define EXT4_FL_XFLAG_VISIBLE           (EXT4_SYNC_FL | \
404                                          EXT4_IMMUTABLE_FL | \
405                                          EXT4_APPEND_FL | \
406                                          EXT4_NODUMP_FL | \
407                                          EXT4_NOATIME_FL | \
408                                          EXT4_PROJINHERIT_FL)
409 
410 /* Flags that should be inherited by new inodes from their parent. */
411 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
412                            EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
413                            EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
414                            EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL |\
415                            EXT4_PROJINHERIT_FL)
416 
417 /* Flags that are appropriate for regular files (all but dir-specific ones). */
418 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
419 
420 /* Flags that are appropriate for non-directories/regular files. */
421 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
422 
423 /* Mask out flags that are inappropriate for the given type of inode. */
424 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
425 {
426         if (S_ISDIR(mode))
427                 return flags;
428         else if (S_ISREG(mode))
429                 return flags & EXT4_REG_FLMASK;
430         else
431                 return flags & EXT4_OTHER_FLMASK;
432 }
433 
434 /*
435  * Inode flags used for atomic set/get
436  */
437 enum {
438         EXT4_INODE_SECRM        = 0,    /* Secure deletion */
439         EXT4_INODE_UNRM         = 1,    /* Undelete */
440         EXT4_INODE_COMPR        = 2,    /* Compress file */
441         EXT4_INODE_SYNC         = 3,    /* Synchronous updates */
442         EXT4_INODE_IMMUTABLE    = 4,    /* Immutable file */
443         EXT4_INODE_APPEND       = 5,    /* writes to file may only append */
444         EXT4_INODE_NODUMP       = 6,    /* do not dump file */
445         EXT4_INODE_NOATIME      = 7,    /* do not update atime */
446 /* Reserved for compression usage... */
447         EXT4_INODE_DIRTY        = 8,
448         EXT4_INODE_COMPRBLK     = 9,    /* One or more compressed clusters */
449         EXT4_INODE_NOCOMPR      = 10,   /* Don't compress */
450         EXT4_INODE_ENCRYPT      = 11,   /* Encrypted file */
451 /* End compression flags --- maybe not all used */
452         EXT4_INODE_INDEX        = 12,   /* hash-indexed directory */
453         EXT4_INODE_IMAGIC       = 13,   /* AFS directory */
454         EXT4_INODE_JOURNAL_DATA = 14,   /* file data should be journaled */
455         EXT4_INODE_NOTAIL       = 15,   /* file tail should not be merged */
456         EXT4_INODE_DIRSYNC      = 16,   /* dirsync behaviour (directories only) */
457         EXT4_INODE_TOPDIR       = 17,   /* Top of directory hierarchies*/
458         EXT4_INODE_HUGE_FILE    = 18,   /* Set to each huge file */
459         EXT4_INODE_EXTENTS      = 19,   /* Inode uses extents */
460         EXT4_INODE_EA_INODE     = 21,   /* Inode used for large EA */
461         EXT4_INODE_EOFBLOCKS    = 22,   /* Blocks allocated beyond EOF */
462         EXT4_INODE_INLINE_DATA  = 28,   /* Data in inode. */
463         EXT4_INODE_PROJINHERIT  = 29,   /* Create with parents projid */
464         EXT4_INODE_RESERVED     = 31,   /* reserved for ext4 lib */
465 };
466 
467 /*
468  * Since it's pretty easy to mix up bit numbers and hex values, we use a
469  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
470  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
471  * any extra space in the compiled kernel image, otherwise, the build will fail.
472  * It's important that these values are the same, since we are using
473  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
474  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
475  * values found in ext2, ext3 and ext4 filesystems, and of course the values
476  * defined in e2fsprogs.
477  *
478  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
479  */
480 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
481 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
482 
483 static inline void ext4_check_flag_values(void)
484 {
485         CHECK_FLAG_VALUE(SECRM);
486         CHECK_FLAG_VALUE(UNRM);
487         CHECK_FLAG_VALUE(COMPR);
488         CHECK_FLAG_VALUE(SYNC);
489         CHECK_FLAG_VALUE(IMMUTABLE);
490         CHECK_FLAG_VALUE(APPEND);
491         CHECK_FLAG_VALUE(NODUMP);
492         CHECK_FLAG_VALUE(NOATIME);
493         CHECK_FLAG_VALUE(DIRTY);
494         CHECK_FLAG_VALUE(COMPRBLK);
495         CHECK_FLAG_VALUE(NOCOMPR);
496         CHECK_FLAG_VALUE(ENCRYPT);
497         CHECK_FLAG_VALUE(INDEX);
498         CHECK_FLAG_VALUE(IMAGIC);
499         CHECK_FLAG_VALUE(JOURNAL_DATA);
500         CHECK_FLAG_VALUE(NOTAIL);
501         CHECK_FLAG_VALUE(DIRSYNC);
502         CHECK_FLAG_VALUE(TOPDIR);
503         CHECK_FLAG_VALUE(HUGE_FILE);
504         CHECK_FLAG_VALUE(EXTENTS);
505         CHECK_FLAG_VALUE(EA_INODE);
506         CHECK_FLAG_VALUE(EOFBLOCKS);
507         CHECK_FLAG_VALUE(INLINE_DATA);
508         CHECK_FLAG_VALUE(PROJINHERIT);
509         CHECK_FLAG_VALUE(RESERVED);
510 }
511 
512 /* Used to pass group descriptor data when online resize is done */
513 struct ext4_new_group_input {
514         __u32 group;            /* Group number for this data */
515         __u64 block_bitmap;     /* Absolute block number of block bitmap */
516         __u64 inode_bitmap;     /* Absolute block number of inode bitmap */
517         __u64 inode_table;      /* Absolute block number of inode table start */
518         __u32 blocks_count;     /* Total number of blocks in this group */
519         __u16 reserved_blocks;  /* Number of reserved blocks in this group */
520         __u16 unused;
521 };
522 
523 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
524 struct compat_ext4_new_group_input {
525         u32 group;
526         compat_u64 block_bitmap;
527         compat_u64 inode_bitmap;
528         compat_u64 inode_table;
529         u32 blocks_count;
530         u16 reserved_blocks;
531         u16 unused;
532 };
533 #endif
534 
535 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
536 struct ext4_new_group_data {
537         __u32 group;
538         __u64 block_bitmap;
539         __u64 inode_bitmap;
540         __u64 inode_table;
541         __u32 blocks_count;
542         __u16 reserved_blocks;
543         __u16 unused;
544         __u32 free_blocks_count;
545 };
546 
547 /* Indexes used to index group tables in ext4_new_group_data */
548 enum {
549         BLOCK_BITMAP = 0,       /* block bitmap */
550         INODE_BITMAP,           /* inode bitmap */
551         INODE_TABLE,            /* inode tables */
552         GROUP_TABLE_COUNT,
553 };
554 
555 /*
556  * Flags used by ext4_map_blocks()
557  */
558         /* Allocate any needed blocks and/or convert an unwritten
559            extent to be an initialized ext4 */
560 #define EXT4_GET_BLOCKS_CREATE                  0x0001
561         /* Request the creation of an unwritten extent */
562 #define EXT4_GET_BLOCKS_UNWRIT_EXT              0x0002
563 #define EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT       (EXT4_GET_BLOCKS_UNWRIT_EXT|\
564                                                  EXT4_GET_BLOCKS_CREATE)
565         /* Caller is from the delayed allocation writeout path
566          * finally doing the actual allocation of delayed blocks */
567 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE        0x0004
568         /* caller is from the direct IO path, request to creation of an
569         unwritten extents if not allocated, split the unwritten
570         extent if blocks has been preallocated already*/
571 #define EXT4_GET_BLOCKS_PRE_IO                  0x0008
572 #define EXT4_GET_BLOCKS_CONVERT                 0x0010
573 #define EXT4_GET_BLOCKS_IO_CREATE_EXT           (EXT4_GET_BLOCKS_PRE_IO|\
574                                          EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
575         /* Convert extent to initialized after IO complete */
576 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT          (EXT4_GET_BLOCKS_CONVERT|\
577                                          EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
578         /* Eventual metadata allocation (due to growing extent tree)
579          * should not fail, so try to use reserved blocks for that.*/
580 #define EXT4_GET_BLOCKS_METADATA_NOFAIL         0x0020
581         /* Don't normalize allocation size (used for fallocate) */
582 #define EXT4_GET_BLOCKS_NO_NORMALIZE            0x0040
583         /* Request will not result in inode size update (user for fallocate) */
584 #define EXT4_GET_BLOCKS_KEEP_SIZE               0x0080
585         /* Convert written extents to unwritten */
586 #define EXT4_GET_BLOCKS_CONVERT_UNWRITTEN       0x0100
587         /* Write zeros to newly created written extents */
588 #define EXT4_GET_BLOCKS_ZERO                    0x0200
589 #define EXT4_GET_BLOCKS_CREATE_ZERO             (EXT4_GET_BLOCKS_CREATE |\
590                                         EXT4_GET_BLOCKS_ZERO)
591         /* Caller will submit data before dropping transaction handle. This
592          * allows jbd2 to avoid submitting data before commit. */
593 #define EXT4_GET_BLOCKS_IO_SUBMIT               0x0400
594 
595 /*
596  * The bit position of these flags must not overlap with any of the
597  * EXT4_GET_BLOCKS_*.  They are used by ext4_find_extent(),
598  * read_extent_tree_block(), ext4_split_extent_at(),
599  * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
600  * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
601  * caching the extents when reading from the extent tree while a
602  * truncate or punch hole operation is in progress.
603  */
604 #define EXT4_EX_NOCACHE                         0x40000000
605 #define EXT4_EX_FORCE_CACHE                     0x20000000
606 
607 /*
608  * Flags used by ext4_free_blocks
609  */
610 #define EXT4_FREE_BLOCKS_METADATA       0x0001
611 #define EXT4_FREE_BLOCKS_FORGET         0x0002
612 #define EXT4_FREE_BLOCKS_VALIDATED      0x0004
613 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE 0x0008
614 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER   0x0010
615 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER    0x0020
616 
617 /*
618  * ioctl commands
619  */
620 #define EXT4_IOC_GETFLAGS               FS_IOC_GETFLAGS
621 #define EXT4_IOC_SETFLAGS               FS_IOC_SETFLAGS
622 #define EXT4_IOC_GETVERSION             _IOR('f', 3, long)
623 #define EXT4_IOC_SETVERSION             _IOW('f', 4, long)
624 #define EXT4_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
625 #define EXT4_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
626 #define EXT4_IOC_GETRSVSZ               _IOR('f', 5, long)
627 #define EXT4_IOC_SETRSVSZ               _IOW('f', 6, long)
628 #define EXT4_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
629 #define EXT4_IOC_GROUP_ADD              _IOW('f', 8, struct ext4_new_group_input)
630 #define EXT4_IOC_MIGRATE                _IO('f', 9)
631  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
632  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
633 #define EXT4_IOC_ALLOC_DA_BLKS          _IO('f', 12)
634 #define EXT4_IOC_MOVE_EXT               _IOWR('f', 15, struct move_extent)
635 #define EXT4_IOC_RESIZE_FS              _IOW('f', 16, __u64)
636 #define EXT4_IOC_SWAP_BOOT              _IO('f', 17)
637 #define EXT4_IOC_PRECACHE_EXTENTS       _IO('f', 18)
638 #define EXT4_IOC_SET_ENCRYPTION_POLICY  FS_IOC_SET_ENCRYPTION_POLICY
639 #define EXT4_IOC_GET_ENCRYPTION_PWSALT  FS_IOC_GET_ENCRYPTION_PWSALT
640 #define EXT4_IOC_GET_ENCRYPTION_POLICY  FS_IOC_GET_ENCRYPTION_POLICY
641 
642 #ifndef FS_IOC_FSGETXATTR
643 /* Until the uapi changes get merged for project quota... */
644 
645 #define FS_IOC_FSGETXATTR               _IOR('X', 31, struct fsxattr)
646 #define FS_IOC_FSSETXATTR               _IOW('X', 32, struct fsxattr)
647 
648 /*
649  * Structure for FS_IOC_FSGETXATTR and FS_IOC_FSSETXATTR.
650  */
651 struct fsxattr {
652         __u32           fsx_xflags;     /* xflags field value (get/set) */
653         __u32           fsx_extsize;    /* extsize field value (get/set)*/
654         __u32           fsx_nextents;   /* nextents field value (get)   */
655         __u32           fsx_projid;     /* project identifier (get/set) */
656         unsigned char   fsx_pad[12];
657 };
658 
659 /*
660  * Flags for the fsx_xflags field
661  */
662 #define FS_XFLAG_REALTIME       0x00000001      /* data in realtime volume */
663 #define FS_XFLAG_PREALLOC       0x00000002      /* preallocated file extents */
664 #define FS_XFLAG_IMMUTABLE      0x00000008      /* file cannot be modified */
665 #define FS_XFLAG_APPEND         0x00000010      /* all writes append */
666 #define FS_XFLAG_SYNC           0x00000020      /* all writes synchronous */
667 #define FS_XFLAG_NOATIME        0x00000040      /* do not update access time */
668 #define FS_XFLAG_NODUMP         0x00000080      /* do not include in backups */
669 #define FS_XFLAG_RTINHERIT      0x00000100      /* create with rt bit set */
670 #define FS_XFLAG_PROJINHERIT    0x00000200      /* create with parents projid */
671 #define FS_XFLAG_NOSYMLINKS     0x00000400      /* disallow symlink creation */
672 #define FS_XFLAG_EXTSIZE        0x00000800      /* extent size allocator hint */
673 #define FS_XFLAG_EXTSZINHERIT   0x00001000      /* inherit inode extent size */
674 #define FS_XFLAG_NODEFRAG       0x00002000      /* do not defragment */
675 #define FS_XFLAG_FILESTREAM     0x00004000      /* use filestream allocator */
676 #define FS_XFLAG_HASATTR        0x80000000      /* no DIFLAG for this */
677 #endif /* !defined(FS_IOC_FSGETXATTR) */
678 
679 #define EXT4_IOC_FSGETXATTR             FS_IOC_FSGETXATTR
680 #define EXT4_IOC_FSSETXATTR             FS_IOC_FSSETXATTR
681 
682 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
683 /*
684  * ioctl commands in 32 bit emulation
685  */
686 #define EXT4_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
687 #define EXT4_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
688 #define EXT4_IOC32_GETVERSION           _IOR('f', 3, int)
689 #define EXT4_IOC32_SETVERSION           _IOW('f', 4, int)
690 #define EXT4_IOC32_GETRSVSZ             _IOR('f', 5, int)
691 #define EXT4_IOC32_SETRSVSZ             _IOW('f', 6, int)
692 #define EXT4_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
693 #define EXT4_IOC32_GROUP_ADD            _IOW('f', 8, struct compat_ext4_new_group_input)
694 #define EXT4_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
695 #define EXT4_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
696 #endif
697 
698 /* Max physical block we can address w/o extents */
699 #define EXT4_MAX_BLOCK_FILE_PHYS        0xFFFFFFFF
700 
701 /*
702  * Structure of an inode on the disk
703  */
704 struct ext4_inode {
705         __le16  i_mode;         /* File mode */
706         __le16  i_uid;          /* Low 16 bits of Owner Uid */
707         __le32  i_size_lo;      /* Size in bytes */
708         __le32  i_atime;        /* Access time */
709         __le32  i_ctime;        /* Inode Change time */
710         __le32  i_mtime;        /* Modification time */
711         __le32  i_dtime;        /* Deletion Time */
712         __le16  i_gid;          /* Low 16 bits of Group Id */
713         __le16  i_links_count;  /* Links count */
714         __le32  i_blocks_lo;    /* Blocks count */
715         __le32  i_flags;        /* File flags */
716         union {
717                 struct {
718                         __le32  l_i_version;
719                 } linux1;
720                 struct {
721                         __u32  h_i_translator;
722                 } hurd1;
723                 struct {
724                         __u32  m_i_reserved1;
725                 } masix1;
726         } osd1;                         /* OS dependent 1 */
727         __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
728         __le32  i_generation;   /* File version (for NFS) */
729         __le32  i_file_acl_lo;  /* File ACL */
730         __le32  i_size_high;
731         __le32  i_obso_faddr;   /* Obsoleted fragment address */
732         union {
733                 struct {
734                         __le16  l_i_blocks_high; /* were l_i_reserved1 */
735                         __le16  l_i_file_acl_high;
736                         __le16  l_i_uid_high;   /* these 2 fields */
737                         __le16  l_i_gid_high;   /* were reserved2[0] */
738                         __le16  l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
739                         __le16  l_i_reserved;
740                 } linux2;
741                 struct {
742                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
743                         __u16   h_i_mode_high;
744                         __u16   h_i_uid_high;
745                         __u16   h_i_gid_high;
746                         __u32   h_i_author;
747                 } hurd2;
748                 struct {
749                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
750                         __le16  m_i_file_acl_high;
751                         __u32   m_i_reserved2[2];
752                 } masix2;
753         } osd2;                         /* OS dependent 2 */
754         __le16  i_extra_isize;
755         __le16  i_checksum_hi;  /* crc32c(uuid+inum+inode) BE */
756         __le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
757         __le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
758         __le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
759         __le32  i_crtime;       /* File Creation time */
760         __le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
761         __le32  i_version_hi;   /* high 32 bits for 64-bit version */
762         __le32  i_projid;       /* Project ID */
763 };
764 
765 struct move_extent {
766         __u32 reserved;         /* should be zero */
767         __u32 donor_fd;         /* donor file descriptor */
768         __u64 orig_start;       /* logical start offset in block for orig */
769         __u64 donor_start;      /* logical start offset in block for donor */
770         __u64 len;              /* block length to be moved */
771         __u64 moved_len;        /* moved block length */
772 };
773 
774 #define EXT4_EPOCH_BITS 2
775 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
776 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
777 
778 /*
779  * Extended fields will fit into an inode if the filesystem was formatted
780  * with large inodes (-I 256 or larger) and there are not currently any EAs
781  * consuming all of the available space. For new inodes we always reserve
782  * enough space for the kernel's known extended fields, but for inodes
783  * created with an old kernel this might not have been the case. None of
784  * the extended inode fields is critical for correct filesystem operation.
785  * This macro checks if a certain field fits in the inode. Note that
786  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
787  */
788 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)   \
789         ((offsetof(typeof(*ext4_inode), field) +        \
790           sizeof((ext4_inode)->field))                  \
791         <= (EXT4_GOOD_OLD_INODE_SIZE +                  \
792             (einode)->i_extra_isize))                   \
793 
794 /*
795  * We use an encoding that preserves the times for extra epoch "00":
796  *
797  * extra  msb of                         adjust for signed
798  * epoch  32-bit                         32-bit tv_sec to
799  * bits   time    decoded 64-bit tv_sec  64-bit tv_sec      valid time range
800  * 0 0    1    -0x80000000..-0x00000001  0x000000000 1901-12-13..1969-12-31
801  * 0 0    0    0x000000000..0x07fffffff  0x000000000 1970-01-01..2038-01-19
802  * 0 1    1    0x080000000..0x0ffffffff  0x100000000 2038-01-19..2106-02-07
803  * 0 1    0    0x100000000..0x17fffffff  0x100000000 2106-02-07..2174-02-25
804  * 1 0    1    0x180000000..0x1ffffffff  0x200000000 2174-02-25..2242-03-16
805  * 1 0    0    0x200000000..0x27fffffff  0x200000000 2242-03-16..2310-04-04
806  * 1 1    1    0x280000000..0x2ffffffff  0x300000000 2310-04-04..2378-04-22
807  * 1 1    0    0x300000000..0x37fffffff  0x300000000 2378-04-22..2446-05-10
808  *
809  * Note that previous versions of the kernel on 64-bit systems would
810  * incorrectly use extra epoch bits 1,1 for dates between 1901 and
811  * 1970.  e2fsck will correct this, assuming that it is run on the
812  * affected filesystem before 2242.
813  */
814 
815 static inline __le32 ext4_encode_extra_time(struct timespec *time)
816 {
817         u32 extra = sizeof(time->tv_sec) > 4 ?
818                 ((time->tv_sec - (s32)time->tv_sec) >> 32) & EXT4_EPOCH_MASK : 0;
819         return cpu_to_le32(extra | (time->tv_nsec << EXT4_EPOCH_BITS));
820 }
821 
822 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
823 {
824         if (unlikely(sizeof(time->tv_sec) > 4 &&
825                         (extra & cpu_to_le32(EXT4_EPOCH_MASK)))) {
826 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,20,0)
827                 /* Handle legacy encoding of pre-1970 dates with epoch
828                  * bits 1,1.  We assume that by kernel version 4.20,
829                  * everyone will have run fsck over the affected
830                  * filesystems to correct the problem.  (This
831                  * backwards compatibility may be removed before this
832                  * time, at the discretion of the ext4 developers.)
833                  */
834                 u64 extra_bits = le32_to_cpu(extra) & EXT4_EPOCH_MASK;
835                 if (extra_bits == 3 && ((time->tv_sec) & 0x80000000) != 0)
836                         extra_bits = 0;
837                 time->tv_sec += extra_bits << 32;
838 #else
839                 time->tv_sec += (u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK) << 32;
840 #endif
841         }
842         time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
843 }
844 
845 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)                          \
846 do {                                                                           \
847         (raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);               \
848         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
849                 (raw_inode)->xtime ## _extra =                                 \
850                                 ext4_encode_extra_time(&(inode)->xtime);       \
851 } while (0)
852 
853 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)                        \
854 do {                                                                           \
855         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
856                 (raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
857         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
858                 (raw_inode)->xtime ## _extra =                                 \
859                                 ext4_encode_extra_time(&(einode)->xtime);      \
860 } while (0)
861 
862 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)                          \
863 do {                                                                           \
864         (inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
865         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
866                 ext4_decode_extra_time(&(inode)->xtime,                        \
867                                        raw_inode->xtime ## _extra);            \
868         else                                                                   \
869                 (inode)->xtime.tv_nsec = 0;                                    \
870 } while (0)
871 
872 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)                        \
873 do {                                                                           \
874         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
875                 (einode)->xtime.tv_sec =                                       \
876                         (signed)le32_to_cpu((raw_inode)->xtime);               \
877         else                                                                   \
878                 (einode)->xtime.tv_sec = 0;                                    \
879         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
880                 ext4_decode_extra_time(&(einode)->xtime,                       \
881                                        raw_inode->xtime ## _extra);            \
882         else                                                                   \
883                 (einode)->xtime.tv_nsec = 0;                                   \
884 } while (0)
885 
886 #define i_disk_version osd1.linux1.l_i_version
887 
888 #if defined(__KERNEL__) || defined(__linux__)
889 #define i_reserved1     osd1.linux1.l_i_reserved1
890 #define i_file_acl_high osd2.linux2.l_i_file_acl_high
891 #define i_blocks_high   osd2.linux2.l_i_blocks_high
892 #define i_uid_low       i_uid
893 #define i_gid_low       i_gid
894 #define i_uid_high      osd2.linux2.l_i_uid_high
895 #define i_gid_high      osd2.linux2.l_i_gid_high
896 #define i_checksum_lo   osd2.linux2.l_i_checksum_lo
897 
898 #elif defined(__GNU__)
899 
900 #define i_translator    osd1.hurd1.h_i_translator
901 #define i_uid_high      osd2.hurd2.h_i_uid_high
902 #define i_gid_high      osd2.hurd2.h_i_gid_high
903 #define i_author        osd2.hurd2.h_i_author
904 
905 #elif defined(__masix__)
906 
907 #define i_reserved1     osd1.masix1.m_i_reserved1
908 #define i_file_acl_high osd2.masix2.m_i_file_acl_high
909 #define i_reserved2     osd2.masix2.m_i_reserved2
910 
911 #endif /* defined(__KERNEL__) || defined(__linux__) */
912 
913 #include "extents_status.h"
914 
915 /*
916  * Lock subclasses for i_data_sem in the ext4_inode_info structure.
917  *
918  * These are needed to avoid lockdep false positives when we need to
919  * allocate blocks to the quota inode during ext4_map_blocks(), while
920  * holding i_data_sem for a normal (non-quota) inode.  Since we don't
921  * do quota tracking for the quota inode, this avoids deadlock (as
922  * well as infinite recursion, since it isn't turtles all the way
923  * down...)
924  *
925  *  I_DATA_SEM_NORMAL - Used for most inodes
926  *  I_DATA_SEM_OTHER  - Used by move_inode.c for the second normal inode
927  *                        where the second inode has larger inode number
928  *                        than the first
929  *  I_DATA_SEM_QUOTA  - Used for quota inodes only
930  */
931 enum {
932         I_DATA_SEM_NORMAL = 0,
933         I_DATA_SEM_OTHER,
934         I_DATA_SEM_QUOTA,
935 };
936 
937 
938 /*
939  * fourth extended file system inode data in memory
940  */
941 struct ext4_inode_info {
942         __le32  i_data[15];     /* unconverted */
943         __u32   i_dtime;
944         ext4_fsblk_t    i_file_acl;
945 
946         /*
947          * i_block_group is the number of the block group which contains
948          * this file's inode.  Constant across the lifetime of the inode,
949          * it is ued for making block allocation decisions - we try to
950          * place a file's data blocks near its inode block, and new inodes
951          * near to their parent directory's inode.
952          */
953         ext4_group_t    i_block_group;
954         ext4_lblk_t     i_dir_start_lookup;
955 #if (BITS_PER_LONG < 64)
956         unsigned long   i_state_flags;          /* Dynamic state flags */
957 #endif
958         unsigned long   i_flags;
959 
960         /*
961          * Extended attributes can be read independently of the main file
962          * data. Taking i_mutex even when reading would cause contention
963          * between readers of EAs and writers of regular file data, so
964          * instead we synchronize on xattr_sem when reading or changing
965          * EAs.
966          */
967         struct rw_semaphore xattr_sem;
968 
969         struct list_head i_orphan;      /* unlinked but open inodes */
970 
971         /*
972          * i_disksize keeps track of what the inode size is ON DISK, not
973          * in memory.  During truncate, i_size is set to the new size by
974          * the VFS prior to calling ext4_truncate(), but the filesystem won't
975          * set i_disksize to 0 until the truncate is actually under way.
976          *
977          * The intent is that i_disksize always represents the blocks which
978          * are used by this file.  This allows recovery to restart truncate
979          * on orphans if we crash during truncate.  We actually write i_disksize
980          * into the on-disk inode when writing inodes out, instead of i_size.
981          *
982          * The only time when i_disksize and i_size may be different is when
983          * a truncate is in progress.  The only things which change i_disksize
984          * are ext4_get_block (growth) and ext4_truncate (shrinkth).
985          */
986         loff_t  i_disksize;
987 
988         /*
989          * i_data_sem is for serialising ext4_truncate() against
990          * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
991          * data tree are chopped off during truncate. We can't do that in
992          * ext4 because whenever we perform intermediate commits during
993          * truncate, the inode and all the metadata blocks *must* be in a
994          * consistent state which allows truncation of the orphans to restart
995          * during recovery.  Hence we must fix the get_block-vs-truncate race
996          * by other means, so we have i_data_sem.
997          */
998         struct rw_semaphore i_data_sem;
999         /*
1000          * i_mmap_sem is for serializing page faults with truncate / punch hole
1001          * operations. We have to make sure that new page cannot be faulted in
1002          * a section of the inode that is being punched. We cannot easily use
1003          * i_data_sem for this since we need protection for the whole punch
1004          * operation and i_data_sem ranks below transaction start so we have
1005          * to occasionally drop it.
1006          */
1007         struct rw_semaphore i_mmap_sem;
1008         struct inode vfs_inode;
1009         struct jbd2_inode *jinode;
1010 
1011         spinlock_t i_raw_lock;  /* protects updates to the raw inode */
1012 
1013         /*
1014          * File creation time. Its function is same as that of
1015          * struct timespec i_{a,c,m}time in the generic inode.
1016          */
1017         struct timespec i_crtime;
1018 
1019         /* mballoc */
1020         struct list_head i_prealloc_list;
1021         spinlock_t i_prealloc_lock;
1022 
1023         /* extents status tree */
1024         struct ext4_es_tree i_es_tree;
1025         rwlock_t i_es_lock;
1026         struct list_head i_es_list;
1027         unsigned int i_es_all_nr;       /* protected by i_es_lock */
1028         unsigned int i_es_shk_nr;       /* protected by i_es_lock */
1029         ext4_lblk_t i_es_shrink_lblk;   /* Offset where we start searching for
1030                                            extents to shrink. Protected by
1031                                            i_es_lock  */
1032 
1033         /* ialloc */
1034         ext4_group_t    i_last_alloc_group;
1035 
1036         /* allocation reservation info for delalloc */
1037         /* In case of bigalloc, these refer to clusters rather than blocks */
1038         unsigned int i_reserved_data_blocks;
1039         unsigned int i_reserved_meta_blocks;
1040         unsigned int i_allocated_meta_blocks;
1041         ext4_lblk_t i_da_metadata_calc_last_lblock;
1042         int i_da_metadata_calc_len;
1043 
1044         /* on-disk additional length */
1045         __u16 i_extra_isize;
1046 
1047         /* Indicate the inline data space. */
1048         u16 i_inline_off;
1049         u16 i_inline_size;
1050 
1051 #ifdef CONFIG_QUOTA
1052         /* quota space reservation, managed internally by quota code */
1053         qsize_t i_reserved_quota;
1054 #endif
1055 
1056         /* Lock protecting lists below */
1057         spinlock_t i_completed_io_lock;
1058         /*
1059          * Completed IOs that need unwritten extents handling and have
1060          * transaction reserved
1061          */
1062         struct list_head i_rsv_conversion_list;
1063         struct work_struct i_rsv_conversion_work;
1064         atomic_t i_unwritten; /* Nr. of inflight conversions pending */
1065 
1066         spinlock_t i_block_reservation_lock;
1067 
1068         /*
1069          * Transactions that contain inode's metadata needed to complete
1070          * fsync and fdatasync, respectively.
1071          */
1072         tid_t i_sync_tid;
1073         tid_t i_datasync_tid;
1074 
1075 #ifdef CONFIG_QUOTA
1076         struct dquot *i_dquot[MAXQUOTAS];
1077 #endif
1078 
1079         /* Precomputed uuid+inum+igen checksum for seeding inode checksums */
1080         __u32 i_csum_seed;
1081 
1082         kprojid_t i_projid;
1083 };
1084 
1085 /*
1086  * File system states
1087  */
1088 #define EXT4_VALID_FS                   0x0001  /* Unmounted cleanly */
1089 #define EXT4_ERROR_FS                   0x0002  /* Errors detected */
1090 #define EXT4_ORPHAN_FS                  0x0004  /* Orphans being recovered */
1091 
1092 /*
1093  * Misc. filesystem flags
1094  */
1095 #define EXT2_FLAGS_SIGNED_HASH          0x0001  /* Signed dirhash in use */
1096 #define EXT2_FLAGS_UNSIGNED_HASH        0x0002  /* Unsigned dirhash in use */
1097 #define EXT2_FLAGS_TEST_FILESYS         0x0004  /* to test development code */
1098 
1099 /*
1100  * Mount flags set via mount options or defaults
1101  */
1102 #define EXT4_MOUNT_GRPID                0x00004 /* Create files with directory's group */
1103 #define EXT4_MOUNT_DEBUG                0x00008 /* Some debugging messages */
1104 #define EXT4_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
1105 #define EXT4_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
1106 #define EXT4_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
1107 #define EXT4_MOUNT_ERRORS_MASK          0x00070
1108 #define EXT4_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
1109 #define EXT4_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
1110 #ifdef CONFIG_FS_DAX
1111 #define EXT4_MOUNT_DAX                  0x00200 /* Direct Access */
1112 #else
1113 #define EXT4_MOUNT_DAX                  0
1114 #endif
1115 #define EXT4_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
1116 #define EXT4_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
1117 #define EXT4_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
1118 #define EXT4_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
1119 #define EXT4_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
1120 #define EXT4_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
1121 #define EXT4_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
1122 #define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
1123 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC     0x10000 /* No auto delalloc mapping */
1124 #define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
1125 #define EXT4_MOUNT_QUOTA                0x40000 /* Some quota option set */
1126 #define EXT4_MOUNT_USRQUOTA             0x80000 /* "old" user quota,
1127                                                  * enable enforcement for hidden
1128                                                  * quota files */
1129 #define EXT4_MOUNT_GRPQUOTA             0x100000 /* "old" group quota, enable
1130                                                   * enforcement for hidden quota
1131                                                   * files */
1132 #define EXT4_MOUNT_PRJQUOTA             0x200000 /* Enable project quota
1133                                                   * enforcement */
1134 #define EXT4_MOUNT_DIOREAD_NOLOCK       0x400000 /* Enable support for dio read nolocking */
1135 #define EXT4_MOUNT_JOURNAL_CHECKSUM     0x800000 /* Journal checksums */
1136 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
1137 #define EXT4_MOUNT_DELALLOC             0x8000000 /* Delalloc support */
1138 #define EXT4_MOUNT_DATA_ERR_ABORT       0x10000000 /* Abort on file data write */
1139 #define EXT4_MOUNT_BLOCK_VALIDITY       0x20000000 /* Block validity checking */
1140 #define EXT4_MOUNT_DISCARD              0x40000000 /* Issue DISCARD requests */
1141 #define EXT4_MOUNT_INIT_INODE_TABLE     0x80000000 /* Initialize uninitialized itables */
1142 
1143 /*
1144  * Mount flags set either automatically (could not be set by mount option)
1145  * based on per file system feature or property or in special cases such as
1146  * distinguishing between explicit mount option definition and default.
1147  */
1148 #define EXT4_MOUNT2_EXPLICIT_DELALLOC   0x00000001 /* User explicitly
1149                                                       specified delalloc */
1150 #define EXT4_MOUNT2_STD_GROUP_SIZE      0x00000002 /* We have standard group
1151                                                       size of blocksize * 8
1152                                                       blocks */
1153 #define EXT4_MOUNT2_HURD_COMPAT         0x00000004 /* Support HURD-castrated
1154                                                       file systems */
1155 
1156 #define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM   0x00000008 /* User explicitly
1157                                                 specified journal checksum */
1158 
1159 #define clear_opt(sb, opt)              EXT4_SB(sb)->s_mount_opt &= \
1160                                                 ~EXT4_MOUNT_##opt
1161 #define set_opt(sb, opt)                EXT4_SB(sb)->s_mount_opt |= \
1162                                                 EXT4_MOUNT_##opt
1163 #define test_opt(sb, opt)               (EXT4_SB(sb)->s_mount_opt & \
1164                                          EXT4_MOUNT_##opt)
1165 
1166 #define clear_opt2(sb, opt)             EXT4_SB(sb)->s_mount_opt2 &= \
1167                                                 ~EXT4_MOUNT2_##opt
1168 #define set_opt2(sb, opt)               EXT4_SB(sb)->s_mount_opt2 |= \
1169                                                 EXT4_MOUNT2_##opt
1170 #define test_opt2(sb, opt)              (EXT4_SB(sb)->s_mount_opt2 & \
1171                                          EXT4_MOUNT2_##opt)
1172 
1173 #define ext4_test_and_set_bit           __test_and_set_bit_le
1174 #define ext4_set_bit                    __set_bit_le
1175 #define ext4_set_bit_atomic             ext2_set_bit_atomic
1176 #define ext4_test_and_clear_bit         __test_and_clear_bit_le
1177 #define ext4_clear_bit                  __clear_bit_le
1178 #define ext4_clear_bit_atomic           ext2_clear_bit_atomic
1179 #define ext4_test_bit                   test_bit_le
1180 #define ext4_find_next_zero_bit         find_next_zero_bit_le
1181 #define ext4_find_next_bit              find_next_bit_le
1182 
1183 extern void ext4_set_bits(void *bm, int cur, int len);
1184 
1185 /*
1186  * Maximal mount counts between two filesystem checks
1187  */
1188 #define EXT4_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
1189 #define EXT4_DFL_CHECKINTERVAL          0       /* Don't use interval check */
1190 
1191 /*
1192  * Behaviour when detecting errors
1193  */
1194 #define EXT4_ERRORS_CONTINUE            1       /* Continue execution */
1195 #define EXT4_ERRORS_RO                  2       /* Remount fs read-only */
1196 #define EXT4_ERRORS_PANIC               3       /* Panic */
1197 #define EXT4_ERRORS_DEFAULT             EXT4_ERRORS_CONTINUE
1198 
1199 /* Metadata checksum algorithm codes */
1200 #define EXT4_CRC32C_CHKSUM              1
1201 
1202 /*
1203  * Structure of the super block
1204  */
1205 struct ext4_super_block {
1206 /*00*/  __le32  s_inodes_count;         /* Inodes count */
1207         __le32  s_blocks_count_lo;      /* Blocks count */
1208         __le32  s_r_blocks_count_lo;    /* Reserved blocks count */
1209         __le32  s_free_blocks_count_lo; /* Free blocks count */
1210 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
1211         __le32  s_first_data_block;     /* First Data Block */
1212         __le32  s_log_block_size;       /* Block size */
1213         __le32  s_log_cluster_size;     /* Allocation cluster size */
1214 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
1215         __le32  s_clusters_per_group;   /* # Clusters per group */
1216         __le32  s_inodes_per_group;     /* # Inodes per group */
1217         __le32  s_mtime;                /* Mount time */
1218 /*30*/  __le32  s_wtime;                /* Write time */
1219         __le16  s_mnt_count;            /* Mount count */
1220         __le16  s_max_mnt_count;        /* Maximal mount count */
1221         __le16  s_magic;                /* Magic signature */
1222         __le16  s_state;                /* File system state */
1223         __le16  s_errors;               /* Behaviour when detecting errors */
1224         __le16  s_minor_rev_level;      /* minor revision level */
1225 /*40*/  __le32  s_lastcheck;            /* time of last check */
1226         __le32  s_checkinterval;        /* max. time between checks */
1227         __le32  s_creator_os;           /* OS */
1228         __le32  s_rev_level;            /* Revision level */
1229 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
1230         __le16  s_def_resgid;           /* Default gid for reserved blocks */
1231         /*
1232          * These fields are for EXT4_DYNAMIC_REV superblocks only.
1233          *
1234          * Note: the difference between the compatible feature set and
1235          * the incompatible feature set is that if there is a bit set
1236          * in the incompatible feature set that the kernel doesn't
1237          * know about, it should refuse to mount the filesystem.
1238          *
1239          * e2fsck's requirements are more strict; if it doesn't know
1240          * about a feature in either the compatible or incompatible
1241          * feature set, it must abort and not try to meddle with
1242          * things it doesn't understand...
1243          */
1244         __le32  s_first_ino;            /* First non-reserved inode */
1245         __le16  s_inode_size;           /* size of inode structure */
1246         __le16  s_block_group_nr;       /* block group # of this superblock */
1247         __le32  s_feature_compat;       /* compatible feature set */
1248 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
1249         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
1250 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
1251 /*78*/  char    s_volume_name[16];      /* volume name */
1252 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
1253 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
1254         /*
1255          * Performance hints.  Directory preallocation should only
1256          * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1257          */
1258         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
1259         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
1260         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
1261         /*
1262          * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1263          */
1264 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
1265 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
1266         __le32  s_journal_dev;          /* device number of journal file */
1267         __le32  s_last_orphan;          /* start of list of inodes to delete */
1268         __le32  s_hash_seed[4];         /* HTREE hash seed */
1269         __u8    s_def_hash_version;     /* Default hash version to use */
1270         __u8    s_jnl_backup_type;
1271         __le16  s_desc_size;            /* size of group descriptor */
1272 /*100*/ __le32  s_default_mount_opts;
1273         __le32  s_first_meta_bg;        /* First metablock block group */
1274         __le32  s_mkfs_time;            /* When the filesystem was created */
1275         __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
1276         /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1277 /*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
1278         __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
1279         __le32  s_free_blocks_count_hi; /* Free blocks count */
1280         __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
1281         __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
1282         __le32  s_flags;                /* Miscellaneous flags */
1283         __le16  s_raid_stride;          /* RAID stride */
1284         __le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1285         __le64  s_mmp_block;            /* Block for multi-mount protection */
1286         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1287         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
1288         __u8    s_checksum_type;        /* metadata checksum algorithm used */
1289         __u8    s_encryption_level;     /* versioning level for encryption */
1290         __u8    s_reserved_pad;         /* Padding to next 32bits */
1291         __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
1292         __le32  s_snapshot_inum;        /* Inode number of active snapshot */
1293         __le32  s_snapshot_id;          /* sequential ID of active snapshot */
1294         __le64  s_snapshot_r_blocks_count; /* reserved blocks for active
1295                                               snapshot's future use */
1296         __le32  s_snapshot_list;        /* inode number of the head of the
1297                                            on-disk snapshot list */
1298 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1299         __le32  s_error_count;          /* number of fs errors */
1300         __le32  s_first_error_time;     /* first time an error happened */
1301         __le32  s_first_error_ino;      /* inode involved in first error */
1302         __le64  s_first_error_block;    /* block involved of first error */
1303         __u8    s_first_error_func[32]; /* function where the error happened */
1304         __le32  s_first_error_line;     /* line number where error happened */
1305         __le32  s_last_error_time;      /* most recent time of an error */
1306         __le32  s_last_error_ino;       /* inode involved in last error */
1307         __le32  s_last_error_line;      /* line number where error happened */
1308         __le64  s_last_error_block;     /* block involved of last error */
1309         __u8    s_last_error_func[32];  /* function where the error happened */
1310 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1311         __u8    s_mount_opts[64];
1312         __le32  s_usr_quota_inum;       /* inode for tracking user quota */
1313         __le32  s_grp_quota_inum;       /* inode for tracking group quota */
1314         __le32  s_overhead_clusters;    /* overhead blocks/clusters in fs */
1315         __le32  s_backup_bgs[2];        /* groups with sparse_super2 SBs */
1316         __u8    s_encrypt_algos[4];     /* Encryption algorithms in use  */
1317         __u8    s_encrypt_pw_salt[16];  /* Salt used for string2key algorithm */
1318         __le32  s_lpf_ino;              /* Location of the lost+found inode */
1319         __le32  s_prj_quota_inum;       /* inode for tracking project quota */
1320         __le32  s_checksum_seed;        /* crc32c(uuid) if csum_seed set */
1321         __le32  s_reserved[98];         /* Padding to the end of the block */
1322         __le32  s_checksum;             /* crc32c(superblock) */
1323 };
1324 
1325 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1326 
1327 #ifdef __KERNEL__
1328 
1329 /*
1330  * run-time mount flags
1331  */
1332 #define EXT4_MF_MNTDIR_SAMPLED          0x0001
1333 #define EXT4_MF_FS_ABORTED              0x0002  /* Fatal error detected */
1334 #define EXT4_MF_TEST_DUMMY_ENCRYPTION   0x0004
1335 
1336 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1337 #define DUMMY_ENCRYPTION_ENABLED(sbi) (unlikely((sbi)->s_mount_flags & \
1338                                                 EXT4_MF_TEST_DUMMY_ENCRYPTION))
1339 #else
1340 #define DUMMY_ENCRYPTION_ENABLED(sbi) (0)
1341 #endif
1342 
1343 /* Number of quota types we support */
1344 #define EXT4_MAXQUOTAS 3
1345 
1346 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1347 #define EXT4_KEY_DESC_PREFIX "ext4:"
1348 #define EXT4_KEY_DESC_PREFIX_SIZE 5
1349 #endif
1350 
1351 /*
1352  * fourth extended-fs super-block data in memory
1353  */
1354 struct ext4_sb_info {
1355         unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
1356         unsigned long s_inodes_per_block;/* Number of inodes per block */
1357         unsigned long s_blocks_per_group;/* Number of blocks in a group */
1358         unsigned long s_clusters_per_group; /* Number of clusters in a group */
1359         unsigned long s_inodes_per_group;/* Number of inodes in a group */
1360         unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
1361         unsigned long s_gdb_count;      /* Number of group descriptor blocks */
1362         unsigned long s_desc_per_block; /* Number of group descriptors per block */
1363         ext4_group_t s_groups_count;    /* Number of groups in the fs */
1364         ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1365         unsigned long s_overhead;  /* # of fs overhead clusters */
1366         unsigned int s_cluster_ratio;   /* Number of blocks per cluster */
1367         unsigned int s_cluster_bits;    /* log2 of s_cluster_ratio */
1368         loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
1369         struct buffer_head * s_sbh;     /* Buffer containing the super block */
1370         struct ext4_super_block *s_es;  /* Pointer to the super block in the buffer */
1371         struct buffer_head **s_group_desc;
1372         unsigned int s_mount_opt;
1373         unsigned int s_mount_opt2;
1374         unsigned int s_mount_flags;
1375         unsigned int s_def_mount_opt;
1376         ext4_fsblk_t s_sb_block;
1377         atomic64_t s_resv_clusters;
1378         kuid_t s_resuid;
1379         kgid_t s_resgid;
1380         unsigned short s_mount_state;
1381         unsigned short s_pad;
1382         int s_addr_per_block_bits;
1383         int s_desc_per_block_bits;
1384         int s_inode_size;
1385         int s_first_ino;
1386         unsigned int s_inode_readahead_blks;
1387         unsigned int s_inode_goal;
1388         spinlock_t s_next_gen_lock;
1389         u32 s_next_generation;
1390         u32 s_hash_seed[4];
1391         int s_def_hash_version;
1392         int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
1393         struct percpu_counter s_freeclusters_counter;
1394         struct percpu_counter s_freeinodes_counter;
1395         struct percpu_counter s_dirs_counter;
1396         struct percpu_counter s_dirtyclusters_counter;
1397         struct blockgroup_lock *s_blockgroup_lock;
1398         struct proc_dir_entry *s_proc;
1399         struct kobject s_kobj;
1400         struct completion s_kobj_unregister;
1401         struct super_block *s_sb;
1402 
1403         /* Journaling */
1404         struct journal_s *s_journal;
1405         struct list_head s_orphan;
1406         struct mutex s_orphan_lock;
1407         unsigned long s_resize_flags;           /* Flags indicating if there
1408                                                    is a resizer */
1409         unsigned long s_commit_interval;
1410         u32 s_max_batch_time;
1411         u32 s_min_batch_time;
1412         struct block_device *journal_bdev;
1413 #ifdef CONFIG_QUOTA
1414         char *s_qf_names[EXT4_MAXQUOTAS];       /* Names of quota files with journalled quota */
1415         int s_jquota_fmt;                       /* Format of quota to use */
1416 #endif
1417         unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1418         struct rb_root system_blks;
1419 
1420 #ifdef EXTENTS_STATS
1421         /* ext4 extents stats */
1422         unsigned long s_ext_min;
1423         unsigned long s_ext_max;
1424         unsigned long s_depth_max;
1425         spinlock_t s_ext_stats_lock;
1426         unsigned long s_ext_blocks;
1427         unsigned long s_ext_extents;
1428 #endif
1429 
1430         /* for buddy allocator */
1431         struct ext4_group_info ***s_group_info;
1432         struct inode *s_buddy_cache;
1433         spinlock_t s_md_lock;
1434         unsigned short *s_mb_offsets;
1435         unsigned int *s_mb_maxs;
1436         unsigned int s_group_info_size;
1437         unsigned int s_mb_free_pending;
1438 
1439         /* tunables */
1440         unsigned long s_stripe;
1441         unsigned int s_mb_stream_request;
1442         unsigned int s_mb_max_to_scan;
1443         unsigned int s_mb_min_to_scan;
1444         unsigned int s_mb_stats;
1445         unsigned int s_mb_order2_reqs;
1446         unsigned int s_mb_group_prealloc;
1447         unsigned int s_max_dir_size_kb;
1448         /* where last allocation was done - for stream allocation */
1449         unsigned long s_mb_last_group;
1450         unsigned long s_mb_last_start;
1451 
1452         /* stats for buddy allocator */
1453         atomic_t s_bal_reqs;    /* number of reqs with len > 1 */
1454         atomic_t s_bal_success; /* we found long enough chunks */
1455         atomic_t s_bal_allocated;       /* in blocks */
1456         atomic_t s_bal_ex_scanned;      /* total extents scanned */
1457         atomic_t s_bal_goals;   /* goal hits */
1458         atomic_t s_bal_breaks;  /* too long searches */
1459         atomic_t s_bal_2orders; /* 2^order hits */
1460         spinlock_t s_bal_lock;
1461         unsigned long s_mb_buddies_generated;
1462         unsigned long long s_mb_generation_time;
1463         atomic_t s_mb_lost_chunks;
1464         atomic_t s_mb_preallocated;
1465         atomic_t s_mb_discarded;
1466         atomic_t s_lock_busy;
1467 
1468         /* locality groups */
1469         struct ext4_locality_group __percpu *s_locality_groups;
1470 
1471         /* for write statistics */
1472         unsigned long s_sectors_written_start;
1473         u64 s_kbytes_written;
1474 
1475         /* the size of zero-out chunk */
1476         unsigned int s_extent_max_zeroout_kb;
1477 
1478         unsigned int s_log_groups_per_flex;
1479         struct flex_groups *s_flex_groups;
1480         ext4_group_t s_flex_groups_allocated;
1481 
1482         /* workqueue for reserved extent conversions (buffered io) */
1483         struct workqueue_struct *rsv_conversion_wq;
1484 
1485         /* timer for periodic error stats printing */
1486         struct timer_list s_err_report;
1487 
1488         /* Lazy inode table initialization info */
1489         struct ext4_li_request *s_li_request;
1490         /* Wait multiplier for lazy initialization thread */
1491         unsigned int s_li_wait_mult;
1492 
1493         /* Kernel thread for multiple mount protection */
1494         struct task_struct *s_mmp_tsk;
1495 
1496         /* record the last minlen when FITRIM is called. */
1497         atomic_t s_last_trim_minblks;
1498 
1499         /* Reference to checksum algorithm driver via cryptoapi */
1500         struct crypto_shash *s_chksum_driver;
1501 
1502         /* Precomputed FS UUID checksum for seeding other checksums */
1503         __u32 s_csum_seed;
1504 
1505         /* Reclaim extents from extent status tree */
1506         struct shrinker s_es_shrinker;
1507         struct list_head s_es_list;     /* List of inodes with reclaimable extents */
1508         long s_es_nr_inode;
1509         struct ext4_es_stats s_es_stats;
1510         struct mb_cache *s_mb_cache;
1511         spinlock_t s_es_lock ____cacheline_aligned_in_smp;
1512 
1513         /* Ratelimit ext4 messages. */
1514         struct ratelimit_state s_err_ratelimit_state;
1515         struct ratelimit_state s_warning_ratelimit_state;
1516         struct ratelimit_state s_msg_ratelimit_state;
1517 
1518         /* Barrier between changing inodes' journal flags and writepages ops. */
1519         struct percpu_rw_semaphore s_journal_flag_rwsem;
1520 
1521         /* Encryption support */
1522 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1523         u8 key_prefix[EXT4_KEY_DESC_PREFIX_SIZE];
1524         u8 key_prefix_size;
1525 #endif
1526 };
1527 
1528 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1529 {
1530         return sb->s_fs_info;
1531 }
1532 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1533 {
1534         return container_of(inode, struct ext4_inode_info, vfs_inode);
1535 }
1536 
1537 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1538 {
1539         return ino == EXT4_ROOT_INO ||
1540                 ino == EXT4_USR_QUOTA_INO ||
1541                 ino == EXT4_GRP_QUOTA_INO ||
1542                 ino == EXT4_BOOT_LOADER_INO ||
1543                 ino == EXT4_JOURNAL_INO ||
1544                 ino == EXT4_RESIZE_INO ||
1545                 (ino >= EXT4_FIRST_INO(sb) &&
1546                  ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1547 }
1548 
1549 /*
1550  * Inode dynamic state flags
1551  */
1552 enum {
1553         EXT4_STATE_JDATA,               /* journaled data exists */
1554         EXT4_STATE_NEW,                 /* inode is newly created */
1555         EXT4_STATE_XATTR,               /* has in-inode xattrs */
1556         EXT4_STATE_NO_EXPAND,           /* No space for expansion */
1557         EXT4_STATE_DA_ALLOC_CLOSE,      /* Alloc DA blks on close */
1558         EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
1559         EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
1560         EXT4_STATE_NEWENTRY,            /* File just added to dir */
1561         EXT4_STATE_DIOREAD_LOCK,        /* Disable support for dio read
1562                                            nolocking */
1563         EXT4_STATE_MAY_INLINE_DATA,     /* may have in-inode data */
1564         EXT4_STATE_EXT_PRECACHED,       /* extents have been precached */
1565 };
1566 
1567 #define EXT4_INODE_BIT_FNS(name, field, offset)                         \
1568 static inline int ext4_test_inode_##name(struct inode *inode, int bit)  \
1569 {                                                                       \
1570         return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);     \
1571 }                                                                       \
1572 static inline void ext4_set_inode_##name(struct inode *inode, int bit)  \
1573 {                                                                       \
1574         set_bit(bit + (offset), &EXT4_I(inode)->i_##field);             \
1575 }                                                                       \
1576 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1577 {                                                                       \
1578         clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);           \
1579 }
1580 
1581 /* Add these declarations here only so that these functions can be
1582  * found by name.  Otherwise, they are very hard to locate. */
1583 static inline int ext4_test_inode_flag(struct inode *inode, int bit);
1584 static inline void ext4_set_inode_flag(struct inode *inode, int bit);
1585 static inline void ext4_clear_inode_flag(struct inode *inode, int bit);
1586 EXT4_INODE_BIT_FNS(flag, flags, 0)
1587 
1588 /* Add these declarations here only so that these functions can be
1589  * found by name.  Otherwise, they are very hard to locate. */
1590 static inline int ext4_test_inode_state(struct inode *inode, int bit);
1591 static inline void ext4_set_inode_state(struct inode *inode, int bit);
1592 static inline void ext4_clear_inode_state(struct inode *inode, int bit);
1593 #if (BITS_PER_LONG < 64)
1594 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1595 
1596 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1597 {
1598         (ei)->i_state_flags = 0;
1599 }
1600 #else
1601 EXT4_INODE_BIT_FNS(state, flags, 32)
1602 
1603 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1604 {
1605         /* We depend on the fact that callers will set i_flags */
1606 }
1607 #endif
1608 #else
1609 /* Assume that user mode programs are passing in an ext4fs superblock, not
1610  * a kernel struct super_block.  This will allow us to call the feature-test
1611  * macros from user land. */
1612 #define EXT4_SB(sb)     (sb)
1613 #endif
1614 
1615 /*
1616  * Returns true if the inode is inode is encrypted
1617  */
1618 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1619 
1620 /*
1621  * Codes for operating systems
1622  */
1623 #define EXT4_OS_LINUX           0
1624 #define EXT4_OS_HURD            1
1625 #define EXT4_OS_MASIX           2
1626 #define EXT4_OS_FREEBSD         3
1627 #define EXT4_OS_LITES           4
1628 
1629 /*
1630  * Revision levels
1631  */
1632 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
1633 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
1634 
1635 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
1636 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
1637 
1638 #define EXT4_GOOD_OLD_INODE_SIZE 128
1639 
1640 /*
1641  * Feature set definitions
1642  */
1643 
1644 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
1645 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
1646 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
1647 #define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
1648 #define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
1649 #define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
1650 #define EXT4_FEATURE_COMPAT_SPARSE_SUPER2       0x0200
1651 
1652 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
1653 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
1654 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
1655 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1656 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
1657 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
1658 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
1659 #define EXT4_FEATURE_RO_COMPAT_QUOTA            0x0100
1660 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC         0x0200
1661 /*
1662  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1663  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1664  * all other data structures' checksums.  However, the METADATA_CSUM and
1665  * GDT_CSUM bits are mutually exclusive.
1666  */
1667 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM    0x0400
1668 #define EXT4_FEATURE_RO_COMPAT_READONLY         0x1000
1669 #define EXT4_FEATURE_RO_COMPAT_PROJECT          0x2000
1670 
1671 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
1672 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
1673 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
1674 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
1675 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
1676 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
1677 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
1678 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1679 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
1680 #define EXT4_FEATURE_INCOMPAT_EA_INODE          0x0400 /* EA in inode */
1681 #define EXT4_FEATURE_INCOMPAT_DIRDATA           0x1000 /* data in dirent */
1682 #define EXT4_FEATURE_INCOMPAT_CSUM_SEED         0x2000
1683 #define EXT4_FEATURE_INCOMPAT_LARGEDIR          0x4000 /* >2GB or 3-lvl htree */
1684 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA       0x8000 /* data in inode */
1685 #define EXT4_FEATURE_INCOMPAT_ENCRYPT           0x10000
1686 
1687 #define EXT4_FEATURE_COMPAT_FUNCS(name, flagname) \
1688 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1689 { \
1690         return ((EXT4_SB(sb)->s_es->s_feature_compat & \
1691                 cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname)) != 0); \
1692 } \
1693 static inline void ext4_set_feature_##name(struct super_block *sb) \
1694 { \
1695         EXT4_SB(sb)->s_es->s_feature_compat |= \
1696                 cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \
1697 } \
1698 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1699 { \
1700         EXT4_SB(sb)->s_es->s_feature_compat &= \
1701                 ~cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \
1702 }
1703 
1704 #define EXT4_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
1705 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1706 { \
1707         return ((EXT4_SB(sb)->s_es->s_feature_ro_compat & \
1708                 cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname)) != 0); \
1709 } \
1710 static inline void ext4_set_feature_##name(struct super_block *sb) \
1711 { \
1712         EXT4_SB(sb)->s_es->s_feature_ro_compat |= \
1713                 cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \
1714 } \
1715 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1716 { \
1717         EXT4_SB(sb)->s_es->s_feature_ro_compat &= \
1718                 ~cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \
1719 }
1720 
1721 #define EXT4_FEATURE_INCOMPAT_FUNCS(name, flagname) \
1722 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1723 { \
1724         return ((EXT4_SB(sb)->s_es->s_feature_incompat & \
1725                 cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname)) != 0); \
1726 } \
1727 static inline void ext4_set_feature_##name(struct super_block *sb) \
1728 { \
1729         EXT4_SB(sb)->s_es->s_feature_incompat |= \
1730                 cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \
1731 } \
1732 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1733 { \
1734         EXT4_SB(sb)->s_es->s_feature_incompat &= \
1735                 ~cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \
1736 }
1737 
1738 EXT4_FEATURE_COMPAT_FUNCS(dir_prealloc,         DIR_PREALLOC)
1739 EXT4_FEATURE_COMPAT_FUNCS(imagic_inodes,        IMAGIC_INODES)
1740 EXT4_FEATURE_COMPAT_FUNCS(journal,              HAS_JOURNAL)
1741 EXT4_FEATURE_COMPAT_FUNCS(xattr,                EXT_ATTR)
1742 EXT4_FEATURE_COMPAT_FUNCS(resize_inode,         RESIZE_INODE)
1743 EXT4_FEATURE_COMPAT_FUNCS(dir_index,            DIR_INDEX)
1744 EXT4_FEATURE_COMPAT_FUNCS(sparse_super2,        SPARSE_SUPER2)
1745 
1746 EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super,      SPARSE_SUPER)
1747 EXT4_FEATURE_RO_COMPAT_FUNCS(large_file,        LARGE_FILE)
1748 EXT4_FEATURE_RO_COMPAT_FUNCS(btree_dir,         BTREE_DIR)
1749 EXT4_FEATURE_RO_COMPAT_FUNCS(huge_file,         HUGE_FILE)
1750 EXT4_FEATURE_RO_COMPAT_FUNCS(gdt_csum,          GDT_CSUM)
1751 EXT4_FEATURE_RO_COMPAT_FUNCS(dir_nlink,         DIR_NLINK)
1752 EXT4_FEATURE_RO_COMPAT_FUNCS(extra_isize,       EXTRA_ISIZE)
1753 EXT4_FEATURE_RO_COMPAT_FUNCS(quota,             QUOTA)
1754 EXT4_FEATURE_RO_COMPAT_FUNCS(bigalloc,          BIGALLOC)
1755 EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum,     METADATA_CSUM)
1756 EXT4_FEATURE_RO_COMPAT_FUNCS(readonly,          READONLY)
1757 EXT4_FEATURE_RO_COMPAT_FUNCS(project,           PROJECT)
1758 
1759 EXT4_FEATURE_INCOMPAT_FUNCS(compression,        COMPRESSION)
1760 EXT4_FEATURE_INCOMPAT_FUNCS(filetype,           FILETYPE)
1761 EXT4_FEATURE_INCOMPAT_FUNCS(journal_needs_recovery,     RECOVER)
1762 EXT4_FEATURE_INCOMPAT_FUNCS(journal_dev,        JOURNAL_DEV)
1763 EXT4_FEATURE_INCOMPAT_FUNCS(meta_bg,            META_BG)
1764 EXT4_FEATURE_INCOMPAT_FUNCS(extents,            EXTENTS)
1765 EXT4_FEATURE_INCOMPAT_FUNCS(64bit,              64BIT)
1766 EXT4_FEATURE_INCOMPAT_FUNCS(mmp,                MMP)
1767 EXT4_FEATURE_INCOMPAT_FUNCS(flex_bg,            FLEX_BG)
1768 EXT4_FEATURE_INCOMPAT_FUNCS(ea_inode,           EA_INODE)
1769 EXT4_FEATURE_INCOMPAT_FUNCS(dirdata,            DIRDATA)
1770 EXT4_FEATURE_INCOMPAT_FUNCS(csum_seed,          CSUM_SEED)
1771 EXT4_FEATURE_INCOMPAT_FUNCS(largedir,           LARGEDIR)
1772 EXT4_FEATURE_INCOMPAT_FUNCS(inline_data,        INLINE_DATA)
1773 EXT4_FEATURE_INCOMPAT_FUNCS(encrypt,            ENCRYPT)
1774 
1775 #define EXT2_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1776 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1777                                          EXT4_FEATURE_INCOMPAT_META_BG)
1778 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1779                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1780                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1781 
1782 #define EXT3_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1783 #define EXT3_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1784                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1785                                          EXT4_FEATURE_INCOMPAT_META_BG)
1786 #define EXT3_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1787                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1788                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1789 
1790 #define EXT4_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1791 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1792                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1793                                          EXT4_FEATURE_INCOMPAT_META_BG| \
1794                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
1795                                          EXT4_FEATURE_INCOMPAT_64BIT| \
1796                                          EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1797                                          EXT4_FEATURE_INCOMPAT_MMP | \
1798                                          EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
1799                                          EXT4_FEATURE_INCOMPAT_ENCRYPT | \
1800                                          EXT4_FEATURE_INCOMPAT_CSUM_SEED)
1801 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1802                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1803                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1804                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1805                                          EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1806                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1807                                          EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1808                                          EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1809                                          EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1810                                          EXT4_FEATURE_RO_COMPAT_QUOTA |\
1811                                          EXT4_FEATURE_RO_COMPAT_PROJECT)
1812 
1813 #define EXTN_FEATURE_FUNCS(ver) \
1814 static inline bool ext4_has_unknown_ext##ver##_compat_features(struct super_block *sb) \
1815 { \
1816         return ((EXT4_SB(sb)->s_es->s_feature_compat & \
1817                 cpu_to_le32(~EXT##ver##_FEATURE_COMPAT_SUPP)) != 0); \
1818 } \
1819 static inline bool ext4_has_unknown_ext##ver##_ro_compat_features(struct super_block *sb) \
1820 { \
1821         return ((EXT4_SB(sb)->s_es->s_feature_ro_compat & \
1822                 cpu_to_le32(~EXT##ver##_FEATURE_RO_COMPAT_SUPP)) != 0); \
1823 } \
1824 static inline bool ext4_has_unknown_ext##ver##_incompat_features(struct super_block *sb) \
1825 { \
1826         return ((EXT4_SB(sb)->s_es->s_feature_incompat & \
1827                 cpu_to_le32(~EXT##ver##_FEATURE_INCOMPAT_SUPP)) != 0); \
1828 }
1829 
1830 EXTN_FEATURE_FUNCS(2)
1831 EXTN_FEATURE_FUNCS(3)
1832 EXTN_FEATURE_FUNCS(4)
1833 
1834 static inline bool ext4_has_compat_features(struct super_block *sb)
1835 {
1836         return (EXT4_SB(sb)->s_es->s_feature_compat != 0);
1837 }
1838 static inline bool ext4_has_ro_compat_features(struct super_block *sb)
1839 {
1840         return (EXT4_SB(sb)->s_es->s_feature_ro_compat != 0);
1841 }
1842 static inline bool ext4_has_incompat_features(struct super_block *sb)
1843 {
1844         return (EXT4_SB(sb)->s_es->s_feature_incompat != 0);
1845 }
1846 
1847 /*
1848  * Default values for user and/or group using reserved blocks
1849  */
1850 #define EXT4_DEF_RESUID         0
1851 #define EXT4_DEF_RESGID         0
1852 
1853 /*
1854  * Default project ID
1855  */
1856 #define EXT4_DEF_PROJID         0
1857 
1858 #define EXT4_DEF_INODE_READAHEAD_BLKS   32
1859 
1860 /*
1861  * Default mount options
1862  */
1863 #define EXT4_DEFM_DEBUG         0x0001
1864 #define EXT4_DEFM_BSDGROUPS     0x0002
1865 #define EXT4_DEFM_XATTR_USER    0x0004
1866 #define EXT4_DEFM_ACL           0x0008
1867 #define EXT4_DEFM_UID16         0x0010
1868 #define EXT4_DEFM_JMODE         0x0060
1869 #define EXT4_DEFM_JMODE_DATA    0x0020
1870 #define EXT4_DEFM_JMODE_ORDERED 0x0040
1871 #define EXT4_DEFM_JMODE_WBACK   0x0060
1872 #define EXT4_DEFM_NOBARRIER     0x0100
1873 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1874 #define EXT4_DEFM_DISCARD       0x0400
1875 #define EXT4_DEFM_NODELALLOC    0x0800
1876 
1877 /*
1878  * Default journal batch times
1879  */
1880 #define EXT4_DEF_MIN_BATCH_TIME 0
1881 #define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1882 
1883 /*
1884  * Minimum number of groups in a flexgroup before we separate out
1885  * directories into the first block group of a flexgroup
1886  */
1887 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1888 
1889 /*
1890  * Structure of a directory entry
1891  */
1892 #define EXT4_NAME_LEN 255
1893 
1894 struct ext4_dir_entry {
1895         __le32  inode;                  /* Inode number */
1896         __le16  rec_len;                /* Directory entry length */
1897         __le16  name_len;               /* Name length */
1898         char    name[EXT4_NAME_LEN];    /* File name */
1899 };
1900 
1901 /*
1902  * The new version of the directory entry.  Since EXT4 structures are
1903  * stored in intel byte order, and the name_len field could never be
1904  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1905  * file_type field.
1906  */
1907 struct ext4_dir_entry_2 {
1908         __le32  inode;                  /* Inode number */
1909         __le16  rec_len;                /* Directory entry length */
1910         __u8    name_len;               /* Name length */
1911         __u8    file_type;
1912         char    name[EXT4_NAME_LEN];    /* File name */
1913 };
1914 
1915 /*
1916  * This is a bogus directory entry at the end of each leaf block that
1917  * records checksums.
1918  */
1919 struct ext4_dir_entry_tail {
1920         __le32  det_reserved_zero1;     /* Pretend to be unused */
1921         __le16  det_rec_len;            /* 12 */
1922         __u8    det_reserved_zero2;     /* Zero name length */
1923         __u8    det_reserved_ft;        /* 0xDE, fake file type */
1924         __le32  det_checksum;           /* crc32c(uuid+inum+dirblock) */
1925 };
1926 
1927 #define EXT4_DIRENT_TAIL(block, blocksize) \
1928         ((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1929                                         ((blocksize) - \
1930                                          sizeof(struct ext4_dir_entry_tail))))
1931 
1932 /*
1933  * Ext4 directory file types.  Only the low 3 bits are used.  The
1934  * other bits are reserved for now.
1935  */
1936 #define EXT4_FT_UNKNOWN         0
1937 #define EXT4_FT_REG_FILE        1
1938 #define EXT4_FT_DIR             2
1939 #define EXT4_FT_CHRDEV          3
1940 #define EXT4_FT_BLKDEV          4
1941 #define EXT4_FT_FIFO            5
1942 #define EXT4_FT_SOCK            6
1943 #define EXT4_FT_SYMLINK         7
1944 
1945 #define EXT4_FT_MAX             8
1946 
1947 #define EXT4_FT_DIR_CSUM        0xDE
1948 
1949 /*
1950  * EXT4_DIR_PAD defines the directory entries boundaries
1951  *
1952  * NOTE: It must be a multiple of 4
1953  */
1954 #define EXT4_DIR_PAD                    4
1955 #define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
1956 #define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
1957                                          ~EXT4_DIR_ROUND)
1958 #define EXT4_MAX_REC_LEN                ((1<<16)-1)
1959 
1960 /*
1961  * If we ever get support for fs block sizes > page_size, we'll need
1962  * to remove the #if statements in the next two functions...
1963  */
1964 static inline unsigned int
1965 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1966 {
1967         unsigned len = le16_to_cpu(dlen);
1968 
1969 #if (PAGE_SIZE >= 65536)
1970         if (len == EXT4_MAX_REC_LEN || len == 0)
1971                 return blocksize;
1972         return (len & 65532) | ((len & 3) << 16);
1973 #else
1974         return len;
1975 #endif
1976 }
1977 
1978 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1979 {
1980         if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1981                 BUG();
1982 #if (PAGE_SIZE >= 65536)
1983         if (len < 65536)
1984                 return cpu_to_le16(len);
1985         if (len == blocksize) {
1986                 if (blocksize == 65536)
1987                         return cpu_to_le16(EXT4_MAX_REC_LEN);
1988                 else
1989                         return cpu_to_le16(0);
1990         }
1991         return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1992 #else
1993         return cpu_to_le16(len);
1994 #endif
1995 }
1996 
1997 /*
1998  * Hash Tree Directory indexing
1999  * (c) Daniel Phillips, 2001
2000  */
2001 
2002 #define is_dx(dir) (ext4_has_feature_dir_index((dir)->i_sb) && \
2003                     ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
2004 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
2005 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
2006 
2007 /* Legal values for the dx_root hash_version field: */
2008 
2009 #define DX_HASH_LEGACY          0
2010 #define DX_HASH_HALF_MD4        1
2011 #define DX_HASH_TEA             2
2012 #define DX_HASH_LEGACY_UNSIGNED 3
2013 #define DX_HASH_HALF_MD4_UNSIGNED       4
2014 #define DX_HASH_TEA_UNSIGNED            5
2015 
2016 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
2017                               const void *address, unsigned int length)
2018 {
2019         struct {
2020                 struct shash_desc shash;
2021                 char ctx[4];
2022         } desc;
2023         int err;
2024 
2025         BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
2026 
2027         desc.shash.tfm = sbi->s_chksum_driver;
2028         desc.shash.flags = 0;
2029         *(u32 *)desc.ctx = crc;
2030 
2031         err = crypto_shash_update(&desc.shash, address, length);
2032         BUG_ON(err);
2033 
2034         return *(u32 *)desc.ctx;
2035 }
2036 
2037 #ifdef __KERNEL__
2038 
2039 /* hash info structure used by the directory hash */
2040 struct dx_hash_info
2041 {
2042         u32             hash;
2043         u32             minor_hash;
2044         int             hash_version;
2045         u32             *seed;
2046 };
2047 
2048 
2049 /* 32 and 64 bit signed EOF for dx directories */
2050 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
2051 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
2052 
2053 
2054 /*
2055  * Control parameters used by ext4_htree_next_block
2056  */
2057 #define HASH_NB_ALWAYS          1
2058 
2059 struct ext4_filename {
2060         const struct qstr *usr_fname;
2061         struct fscrypt_str disk_name;
2062         struct dx_hash_info hinfo;
2063 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2064         struct fscrypt_str crypto_buf;
2065 #endif
2066 };
2067 
2068 #define fname_name(p) ((p)->disk_name.name)
2069 #define fname_len(p)  ((p)->disk_name.len)
2070 
2071 /*
2072  * Describe an inode's exact location on disk and in memory
2073  */
2074 struct ext4_iloc
2075 {
2076         struct buffer_head *bh;
2077         unsigned long offset;
2078         ext4_group_t block_group;
2079 };
2080 
2081 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
2082 {
2083         return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
2084 }
2085 
2086 /*
2087  * This structure is stuffed into the struct file's private_data field
2088  * for directories.  It is where we put information so that we can do
2089  * readdir operations in hash tree order.
2090  */
2091 struct dir_private_info {
2092         struct rb_root  root;
2093         struct rb_node  *curr_node;
2094         struct fname    *extra_fname;
2095         loff_t          last_pos;
2096         __u32           curr_hash;
2097         __u32           curr_minor_hash;
2098         __u32           next_hash;
2099 };
2100 
2101 /* calculate the first block number of the group */
2102 static inline ext4_fsblk_t
2103 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
2104 {
2105         return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
2106                 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
2107 }
2108 
2109 /*
2110  * Special error return code only used by dx_probe() and its callers.
2111  */
2112 #define ERR_BAD_DX_DIR  (-(MAX_ERRNO - 1))
2113 
2114 /*
2115  * Timeout and state flag for lazy initialization inode thread.
2116  */
2117 #define EXT4_DEF_LI_WAIT_MULT                   10
2118 #define EXT4_DEF_LI_MAX_START_DELAY             5
2119 #define EXT4_LAZYINIT_QUIT                      0x0001
2120 #define EXT4_LAZYINIT_RUNNING                   0x0002
2121 
2122 /*
2123  * Lazy inode table initialization info
2124  */
2125 struct ext4_lazy_init {
2126         unsigned long           li_state;
2127         struct list_head        li_request_list;
2128         struct mutex            li_list_mtx;
2129 };
2130 
2131 struct ext4_li_request {
2132         struct super_block      *lr_super;
2133         struct ext4_sb_info     *lr_sbi;
2134         ext4_group_t            lr_next_group;
2135         struct list_head        lr_request;
2136         unsigned long           lr_next_sched;
2137         unsigned long           lr_timeout;
2138 };
2139 
2140 struct ext4_features {
2141         struct kobject f_kobj;
2142         struct completion f_kobj_unregister;
2143 };
2144 
2145 /*
2146  * This structure will be used for multiple mount protection. It will be
2147  * written into the block number saved in the s_mmp_block field in the
2148  * superblock. Programs that check MMP should assume that if
2149  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
2150  * to use the filesystem, regardless of how old the timestamp is.
2151  */
2152 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
2153 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
2154 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
2155 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
2156 
2157 struct mmp_struct {
2158         __le32  mmp_magic;              /* Magic number for MMP */
2159         __le32  mmp_seq;                /* Sequence no. updated periodically */
2160 
2161         /*
2162          * mmp_time, mmp_nodename & mmp_bdevname are only used for information
2163          * purposes and do not affect the correctness of the algorithm
2164          */
2165         __le64  mmp_time;               /* Time last updated */
2166         char    mmp_nodename[64];       /* Node which last updated MMP block */
2167         char    mmp_bdevname[32];       /* Bdev which last updated MMP block */
2168 
2169         /*
2170          * mmp_check_interval is used to verify if the MMP block has been
2171          * updated on the block device. The value is updated based on the
2172          * maximum time to write the MMP block during an update cycle.
2173          */
2174         __le16  mmp_check_interval;
2175 
2176         __le16  mmp_pad1;
2177         __le32  mmp_pad2[226];
2178         __le32  mmp_checksum;           /* crc32c(uuid+mmp_block) */
2179 };
2180 
2181 /* arguments passed to the mmp thread */
2182 struct mmpd_data {
2183         struct buffer_head *bh; /* bh from initial read_mmp_block() */
2184         struct super_block *sb;  /* super block of the fs */
2185 };
2186 
2187 /*
2188  * Check interval multiplier
2189  * The MMP block is written every update interval and initially checked every
2190  * update interval x the multiplier (the value is then adapted based on the
2191  * write latency). The reason is that writes can be delayed under load and we
2192  * don't want readers to incorrectly assume that the filesystem is no longer
2193  * in use.
2194  */
2195 #define EXT4_MMP_CHECK_MULT             2UL
2196 
2197 /*
2198  * Minimum interval for MMP checking in seconds.
2199  */
2200 #define EXT4_MMP_MIN_CHECK_INTERVAL     5UL
2201 
2202 /*
2203  * Maximum interval for MMP checking in seconds.
2204  */
2205 #define EXT4_MMP_MAX_CHECK_INTERVAL     300UL
2206 
2207 /*
2208  * Function prototypes
2209  */
2210 
2211 /*
2212  * Ok, these declarations are also in <linux/kernel.h> but none of the
2213  * ext4 source programs needs to include it so they are duplicated here.
2214  */
2215 # define NORET_TYPE     /**/
2216 # define ATTRIB_NORET   __attribute__((noreturn))
2217 # define NORET_AND      noreturn,
2218 
2219 /* bitmap.c */
2220 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
2221 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
2222                                 struct ext4_group_desc *gdp,
2223                                 struct buffer_head *bh, int sz);
2224 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
2225                                   struct ext4_group_desc *gdp,
2226                                   struct buffer_head *bh, int sz);
2227 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
2228                                 struct ext4_group_desc *gdp,
2229                                 struct buffer_head *bh);
2230 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
2231                                   struct ext4_group_desc *gdp,
2232                                   struct buffer_head *bh);
2233 
2234 /* balloc.c */
2235 extern void ext4_get_group_no_and_offset(struct super_block *sb,
2236                                          ext4_fsblk_t blocknr,
2237                                          ext4_group_t *blockgrpp,
2238                                          ext4_grpblk_t *offsetp);
2239 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
2240                                           ext4_fsblk_t block);
2241 
2242 extern unsigned int ext4_block_group(struct super_block *sb,
2243                         ext4_fsblk_t blocknr);
2244 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
2245                         ext4_fsblk_t blocknr);
2246 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
2247 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
2248                         ext4_group_t group);
2249 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
2250                                          ext4_fsblk_t goal,
2251                                          unsigned int flags,
2252                                          unsigned long *count,
2253                                          int *errp);
2254 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
2255                                     s64 nclusters, unsigned int flags);
2256 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
2257 extern void ext4_check_blocks_bitmap(struct super_block *);
2258 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
2259                                                     ext4_group_t block_group,
2260                                                     struct buffer_head ** bh);
2261 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
2262 
2263 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
2264                                                 ext4_group_t block_group);
2265 extern int ext4_wait_block_bitmap(struct super_block *sb,
2266                                   ext4_group_t block_group,
2267                                   struct buffer_head *bh);
2268 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
2269                                                   ext4_group_t block_group);
2270 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
2271                                               ext4_group_t block_group,
2272                                               struct ext4_group_desc *gdp);
2273 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
2274 
2275 static inline bool ext4_encrypted_inode(struct inode *inode)
2276 {
2277         return ext4_test_inode_flag(inode, EXT4_INODE_ENCRYPT);
2278 }
2279 
2280 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2281 static inline int ext4_fname_setup_filename(struct inode *dir,
2282                         const struct qstr *iname,
2283                         int lookup, struct ext4_filename *fname)
2284 {
2285         struct fscrypt_name name;
2286         int err;
2287 
2288         memset(fname, 0, sizeof(struct ext4_filename));
2289 
2290         err = fscrypt_setup_filename(dir, iname, lookup, &name);
2291 
2292         fname->usr_fname = name.usr_fname;
2293         fname->disk_name = name.disk_name;
2294         fname->hinfo.hash = name.hash;
2295         fname->hinfo.minor_hash = name.minor_hash;
2296         fname->crypto_buf = name.crypto_buf;
2297         return err;
2298 }
2299 
2300 static inline void ext4_fname_free_filename(struct ext4_filename *fname)
2301 {
2302         struct fscrypt_name name;
2303 
2304         name.crypto_buf = fname->crypto_buf;
2305         fscrypt_free_filename(&name);
2306 
2307         fname->crypto_buf.name = NULL;
2308         fname->usr_fname = NULL;
2309         fname->disk_name.name = NULL;
2310 }
2311 #else
2312 static inline int ext4_fname_setup_filename(struct inode *dir,
2313                 const struct qstr *iname,
2314                 int lookup, struct ext4_filename *fname)
2315 {
2316         fname->usr_fname = iname;
2317         fname->disk_name.name = (unsigned char *) iname->name;
2318         fname->disk_name.len = iname->len;
2319         return 0;
2320 }
2321 static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
2322 
2323 #define fscrypt_set_d_op(i)
2324 #define fscrypt_get_ctx                 fscrypt_notsupp_get_ctx
2325 #define fscrypt_release_ctx             fscrypt_notsupp_release_ctx
2326 #define fscrypt_encrypt_page            fscrypt_notsupp_encrypt_page
2327 #define fscrypt_decrypt_page            fscrypt_notsupp_decrypt_page
2328 #define fscrypt_decrypt_bio_pages       fscrypt_notsupp_decrypt_bio_pages
2329 #define fscrypt_pullback_bio_page       fscrypt_notsupp_pullback_bio_page
2330 #define fscrypt_restore_control_page    fscrypt_notsupp_restore_control_page
2331 #define fscrypt_zeroout_range           fscrypt_notsupp_zeroout_range
2332 #define fscrypt_ioctl_set_policy        fscrypt_notsupp_ioctl_set_policy
2333 #define fscrypt_ioctl_get_policy        fscrypt_notsupp_ioctl_get_policy
2334 #define fscrypt_has_permitted_context   fscrypt_notsupp_has_permitted_context
2335 #define fscrypt_inherit_context         fscrypt_notsupp_inherit_context
2336 #define fscrypt_get_encryption_info     fscrypt_notsupp_get_encryption_info
2337 #define fscrypt_put_encryption_info     fscrypt_notsupp_put_encryption_info
2338 #define fscrypt_setup_filename          fscrypt_notsupp_setup_filename
2339 #define fscrypt_free_filename           fscrypt_notsupp_free_filename
2340 #define fscrypt_fname_encrypted_size    fscrypt_notsupp_fname_encrypted_size
2341 #define fscrypt_fname_alloc_buffer      fscrypt_notsupp_fname_alloc_buffer
2342 #define fscrypt_fname_free_buffer       fscrypt_notsupp_fname_free_buffer
2343 #define fscrypt_fname_disk_to_usr       fscrypt_notsupp_fname_disk_to_usr
2344 #define fscrypt_fname_usr_to_disk       fscrypt_notsupp_fname_usr_to_disk
2345 #endif
2346 
2347 /* dir.c */
2348 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
2349                                   struct file *,
2350                                   struct ext4_dir_entry_2 *,
2351                                   struct buffer_head *, char *, int,
2352                                   unsigned int);
2353 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)      \
2354         unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
2355                                         (de), (bh), (buf), (size), (offset)))
2356 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
2357                                 __u32 minor_hash,
2358                                 struct ext4_dir_entry_2 *dirent,
2359                                 struct fscrypt_str *ent_name);
2360 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
2361 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2362                              struct buffer_head *bh,
2363                              void *buf, int buf_size,
2364                              struct ext4_filename *fname,
2365                              struct ext4_dir_entry_2 **dest_de);
2366 int ext4_insert_dentry(struct inode *dir,
2367                        struct inode *inode,
2368                        struct ext4_dir_entry_2 *de,
2369                        int buf_size,
2370                        struct ext4_filename *fname);
2371 static inline void ext4_update_dx_flag(struct inode *inode)
2372 {
2373         if (!ext4_has_feature_dir_index(inode->i_sb))
2374                 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
2375 }
2376 static unsigned char ext4_filetype_table[] = {
2377         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
2378 };
2379 
2380 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
2381 {
2382         if (!ext4_has_feature_filetype(sb) || filetype >= EXT4_FT_MAX)
2383                 return DT_UNKNOWN;
2384 
2385         return ext4_filetype_table[filetype];
2386 }
2387 extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
2388                              void *buf, int buf_size);
2389 
2390 /* fsync.c */
2391 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2392 
2393 /* hash.c */
2394 extern int ext4fs_dirhash(const char *name, int len, struct
2395                           dx_hash_info *hinfo);
2396 
2397 /* ialloc.c */
2398 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
2399                                       const struct qstr *qstr, __u32 goal,
2400                                       uid_t *owner, int handle_type,
2401                                       unsigned int line_no, int nblocks);
2402 
2403 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner) \
2404         __ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
2405                          0, 0, 0)
2406 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
2407                                     type, nblocks)                  \
2408         __ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2409                          (type), __LINE__, (nblocks))
2410 
2411 
2412 extern void ext4_free_inode(handle_t *, struct inode *);
2413 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2414 extern unsigned long ext4_count_free_inodes(struct super_block *);
2415 extern unsigned long ext4_count_dirs(struct super_block *);
2416 extern void ext4_check_inodes_bitmap(struct super_block *);
2417 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2418 extern int ext4_init_inode_table(struct super_block *sb,
2419                                  ext4_group_t group, int barrier);
2420 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2421 
2422 /* mballoc.c */
2423 extern const struct file_operations ext4_seq_mb_groups_fops;
2424 extern long ext4_mb_stats;
2425 extern long ext4_mb_max_to_scan;
2426 extern int ext4_mb_init(struct super_block *);
2427 extern int ext4_mb_release(struct super_block *);
2428 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2429                                 struct ext4_allocation_request *, int *);
2430 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2431 extern void ext4_discard_preallocations(struct inode *);
2432 extern int __init ext4_init_mballoc(void);
2433 extern void ext4_exit_mballoc(void);
2434 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2435                              struct buffer_head *bh, ext4_fsblk_t block,
2436                              unsigned long count, int flags);
2437 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2438                                    ext4_group_t ngroups);
2439 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2440                 ext4_group_t i, struct ext4_group_desc *desc);
2441 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2442                                 ext4_fsblk_t block, unsigned long count);
2443 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2444 
2445 /* inode.c */
2446 int ext4_inode_is_fast_symlink(struct inode *inode);
2447 struct buffer_head *ext4_getblk(handle_t *, struct inode *, ext4_lblk_t, int);
2448 struct buffer_head *ext4_bread(handle_t *, struct inode *, ext4_lblk_t, int);
2449 int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
2450                              struct buffer_head *bh_result, int create);
2451 int ext4_get_block(struct inode *inode, sector_t iblock,
2452                    struct buffer_head *bh_result, int create);
2453 int ext4_dio_get_block(struct inode *inode, sector_t iblock,
2454                        struct buffer_head *bh_result, int create);
2455 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2456                            struct buffer_head *bh, int create);
2457 int ext4_walk_page_buffers(handle_t *handle,
2458                            struct buffer_head *head,
2459                            unsigned from,
2460                            unsigned to,
2461                            int *partial,
2462                            int (*fn)(handle_t *handle,
2463                                      struct buffer_head *bh));
2464 int do_journal_get_write_access(handle_t *handle,
2465                                 struct buffer_head *bh);
2466 #define FALL_BACK_TO_NONDELALLOC 1
2467 #define CONVERT_INLINE_DATA      2
2468 
2469 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2470 extern struct inode *ext4_iget_normal(struct super_block *, unsigned long);
2471 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2472 extern int  ext4_setattr(struct dentry *, struct iattr *);
2473 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2474                                 struct kstat *stat);
2475 extern void ext4_evict_inode(struct inode *);
2476 extern void ext4_clear_inode(struct inode *);
2477 extern int  ext4_sync_inode(handle_t *, struct inode *);
2478 extern void ext4_dirty_inode(struct inode *, int);
2479 extern int ext4_change_inode_journal_flag(struct inode *, int);
2480 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2481 extern int ext4_inode_attach_jinode(struct inode *inode);
2482 extern int ext4_can_truncate(struct inode *inode);
2483 extern int ext4_truncate(struct inode *);
2484 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
2485 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2486 extern void ext4_set_inode_flags(struct inode *);
2487 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2488 extern int ext4_alloc_da_blocks(struct inode *inode);
2489 extern void ext4_set_aops(struct inode *inode);
2490 extern int ext4_writepage_trans_blocks(struct inode *);
2491 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2492 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2493                              loff_t lstart, loff_t lend);
2494 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2495 extern int ext4_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf);
2496 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2497 extern int ext4_get_projid(struct inode *inode, kprojid_t *projid);
2498 extern void ext4_da_update_reserve_space(struct inode *inode,
2499                                         int used, int quota_claim);
2500 extern int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk,
2501                               ext4_fsblk_t pblk, ext4_lblk_t len);
2502 extern int ext4_get_next_extent(struct inode *inode, ext4_lblk_t lblk,
2503                                 unsigned int map_len,
2504                                 struct extent_status *result);
2505 
2506 /* indirect.c */
2507 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2508                                 struct ext4_map_blocks *map, int flags);
2509 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2510 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2511 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2512 extern int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
2513                                  ext4_lblk_t start, ext4_lblk_t end);
2514 
2515 /* ioctl.c */
2516 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2517 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2518 
2519 /* migrate.c */
2520 extern int ext4_ext_migrate(struct inode *);
2521 extern int ext4_ind_migrate(struct inode *inode);
2522 
2523 /* namei.c */
2524 extern int ext4_dirent_csum_verify(struct inode *inode,
2525                                    struct ext4_dir_entry *dirent);
2526 extern int ext4_orphan_add(handle_t *, struct inode *);
2527 extern int ext4_orphan_del(handle_t *, struct inode *);
2528 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2529                                 __u32 start_minor_hash, __u32 *next_hash);
2530 extern int ext4_search_dir(struct buffer_head *bh,
2531                            char *search_buf,
2532                            int buf_size,
2533                            struct inode *dir,
2534                            struct ext4_filename *fname,
2535                            const struct qstr *d_name,
2536                            unsigned int offset,
2537                            struct ext4_dir_entry_2 **res_dir);
2538 extern int ext4_generic_delete_entry(handle_t *handle,
2539                                      struct inode *dir,
2540                                      struct ext4_dir_entry_2 *de_del,
2541                                      struct buffer_head *bh,
2542                                      void *entry_buf,
2543                                      int buf_size,
2544                                      int csum_size);
2545 extern bool ext4_empty_dir(struct inode *inode);
2546 
2547 /* resize.c */
2548 extern int ext4_group_add(struct super_block *sb,
2549                                 struct ext4_new_group_data *input);
2550 extern int ext4_group_extend(struct super_block *sb,
2551                                 struct ext4_super_block *es,
2552                                 ext4_fsblk_t n_blocks_count);
2553 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2554 
2555 /* super.c */
2556 extern int ext4_seq_options_show(struct seq_file *seq, void *offset);
2557 extern int ext4_calculate_overhead(struct super_block *sb);
2558 extern void ext4_superblock_csum_set(struct super_block *sb);
2559 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2560 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2561 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2562                                     ext4_group_t ngroup);
2563 extern const char *ext4_decode_error(struct super_block *sb, int errno,
2564                                      char nbuf[16]);
2565 
2566 extern __printf(4, 5)
2567 void __ext4_error(struct super_block *, const char *, unsigned int,
2568                   const char *, ...);
2569 extern __printf(5, 6)
2570 void __ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2571                       const char *, ...);
2572 extern __printf(5, 6)
2573 void __ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2574                      const char *, ...);
2575 extern void __ext4_std_error(struct super_block *, const char *,
2576                              unsigned int, int);
2577 extern __printf(4, 5)
2578 void __ext4_abort(struct super_block *, const char *, unsigned int,
2579                   const char *, ...);
2580 extern __printf(4, 5)
2581 void __ext4_warning(struct super_block *, const char *, unsigned int,
2582                     const char *, ...);
2583 extern __printf(4, 5)
2584 void __ext4_warning_inode(const struct inode *inode, const char *function,
2585                           unsigned int line, const char *fmt, ...);
2586 extern __printf(3, 4)
2587 void __ext4_msg(struct super_block *, const char *, const char *, ...);
2588 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2589                            const char *, unsigned int, const char *);
2590 extern __printf(7, 8)
2591 void __ext4_grp_locked_error(const char *, unsigned int,
2592                              struct super_block *, ext4_group_t,
2593                              unsigned long, ext4_fsblk_t,
2594                              const char *, ...);
2595 
2596 #define EXT4_ERROR_INODE(inode, fmt, a...) \
2597         ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
2598 
2599 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)                 \
2600         ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
2601 
2602 #define EXT4_ERROR_FILE(file, block, fmt, a...)                         \
2603         ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
2604 
2605 #ifdef CONFIG_PRINTK
2606 
2607 #define ext4_error_inode(inode, func, line, block, fmt, ...)            \
2608         __ext4_error_inode(inode, func, line, block, fmt, ##__VA_ARGS__)
2609 #define ext4_error_file(file, func, line, block, fmt, ...)              \
2610         __ext4_error_file(file, func, line, block, fmt, ##__VA_ARGS__)
2611 #define ext4_error(sb, fmt, ...)                                        \
2612         __ext4_error(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2613 #define ext4_abort(sb, fmt, ...)                                        \
2614         __ext4_abort(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2615 #define ext4_warning(sb, fmt, ...)                                      \
2616         __ext4_warning(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2617 #define ext4_warning_inode(inode, fmt, ...)                             \
2618         __ext4_warning_inode(inode, __func__, __LINE__, fmt, ##__VA_ARGS__)
2619 #define ext4_msg(sb, level, fmt, ...)                           \
2620         __ext4_msg(sb, level, fmt, ##__VA_ARGS__)
2621 #define dump_mmp_msg(sb, mmp, msg)                                      \
2622         __dump_mmp_msg(sb, mmp, __func__, __LINE__, msg)
2623 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)            \
2624         __ext4_grp_locked_error(__func__, __LINE__, sb, grp, ino, block, \
2625                                 fmt, ##__VA_ARGS__)
2626 
2627 #else
2628 
2629 #define ext4_error_inode(inode, func, line, block, fmt, ...)            \
2630 do {                                                                    \
2631         no_printk(fmt, ##__VA_ARGS__);                                  \
2632         __ext4_error_inode(inode, "", 0, block, " ");                   \
2633 } while (0)
2634 #define ext4_error_file(file, func, line, block, fmt, ...)              \
2635 do {                                                                    \
2636         no_printk(fmt, ##__VA_ARGS__);                                  \
2637         __ext4_error_file(file, "", 0, block, " ");                     \
2638 } while (0)
2639 #define ext4_error(sb, fmt, ...)                                        \
2640 do {                                                                    \
2641         no_printk(fmt, ##__VA_ARGS__);                                  \
2642         __ext4_error(sb, "", 0, " ");                                   \
2643 } while (0)
2644 #define ext4_abort(sb, fmt, ...)                                        \
2645 do {                                                                    \
2646         no_printk(fmt, ##__VA_ARGS__);                                  \
2647         __ext4_abort(sb, "", 0, " ");                                   \
2648 } while (0)
2649 #define ext4_warning(sb, fmt, ...)                                      \
2650 do {                                                                    \
2651         no_printk(fmt, ##__VA_ARGS__);                                  \
2652         __ext4_warning(sb, "", 0, " ");                                 \
2653 } while (0)
2654 #define ext4_warning_inode(inode, fmt, ...)                             \
2655 do {                                                                    \
2656         no_printk(fmt, ##__VA_ARGS__);                                  \
2657         __ext4_warning_inode(inode, "", 0, " ");                        \
2658 } while (0)
2659 #define ext4_msg(sb, level, fmt, ...)                                   \
2660 do {                                                                    \
2661         no_printk(fmt, ##__VA_ARGS__);                                  \
2662         __ext4_msg(sb, "", " ");                                        \
2663 } while (0)
2664 #define dump_mmp_msg(sb, mmp, msg)                                      \
2665         __dump_mmp_msg(sb, mmp, "", 0, "")
2666 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)            \
2667 do {                                                                    \
2668         no_printk(fmt, ##__VA_ARGS__);                          \
2669         __ext4_grp_locked_error("", 0, sb, grp, ino, block, " ");       \
2670 } while (0)
2671 
2672 #endif
2673 
2674 extern void ext4_update_dynamic_rev(struct super_block *sb);
2675 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2676                                         __u32 compat);
2677 extern int ext4_update_rocompat_feature(handle_t *handle,
2678                                         struct super_block *sb, __u32 rocompat);
2679 extern int ext4_update_incompat_feature(handle_t *handle,
2680                                         struct super_block *sb, __u32 incompat);
2681 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2682                                       struct ext4_group_desc *bg);
2683 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2684                                       struct ext4_group_desc *bg);
2685 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2686                                      struct ext4_group_desc *bg);
2687 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2688                                       struct ext4_group_desc *bg);
2689 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2690                                  struct ext4_group_desc *bg);
2691 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2692                                 struct ext4_group_desc *bg);
2693 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2694                                    struct ext4_group_desc *bg);
2695 extern void ext4_block_bitmap_set(struct super_block *sb,
2696                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2697 extern void ext4_inode_bitmap_set(struct super_block *sb,
2698                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2699 extern void ext4_inode_table_set(struct super_block *sb,
2700                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2701 extern void ext4_free_group_clusters_set(struct super_block *sb,
2702                                          struct ext4_group_desc *bg,
2703                                          __u32 count);
2704 extern void ext4_free_inodes_set(struct super_block *sb,
2705                                 struct ext4_group_desc *bg, __u32 count);
2706 extern void ext4_used_dirs_set(struct super_block *sb,
2707                                 struct ext4_group_desc *bg, __u32 count);
2708 extern void ext4_itable_unused_set(struct super_block *sb,
2709                                    struct ext4_group_desc *bg, __u32 count);
2710 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2711                                        struct ext4_group_desc *gdp);
2712 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2713                                      struct ext4_group_desc *gdp);
2714 extern int ext4_register_li_request(struct super_block *sb,
2715                                     ext4_group_t first_not_zeroed);
2716 
2717 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2718 {
2719         return ext4_has_feature_gdt_csum(sb) ||
2720                EXT4_SB(sb)->s_chksum_driver != NULL;
2721 }
2722 
2723 static inline int ext4_has_metadata_csum(struct super_block *sb)
2724 {
2725         WARN_ON_ONCE(ext4_has_feature_metadata_csum(sb) &&
2726                      !EXT4_SB(sb)->s_chksum_driver);
2727 
2728         return (EXT4_SB(sb)->s_chksum_driver != NULL);
2729 }
2730 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2731 {
2732         return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2733                 le32_to_cpu(es->s_blocks_count_lo);
2734 }
2735 
2736 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2737 {
2738         return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2739                 le32_to_cpu(es->s_r_blocks_count_lo);
2740 }
2741 
2742 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2743 {
2744         return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2745                 le32_to_cpu(es->s_free_blocks_count_lo);
2746 }
2747 
2748 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2749                                          ext4_fsblk_t blk)
2750 {
2751         es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2752         es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2753 }
2754 
2755 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2756                                               ext4_fsblk_t blk)
2757 {
2758         es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2759         es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2760 }
2761 
2762 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2763                                            ext4_fsblk_t blk)
2764 {
2765         es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2766         es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2767 }
2768 
2769 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2770 {
2771         if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2772                 return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2773                         le32_to_cpu(raw_inode->i_size_lo);
2774         else
2775                 return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2776 }
2777 
2778 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2779 {
2780         raw_inode->i_size_lo = cpu_to_le32(i_size);
2781         raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2782 }
2783 
2784 static inline
2785 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2786                                             ext4_group_t group)
2787 {
2788          struct ext4_group_info ***grp_info;
2789          long indexv, indexh;
2790          BUG_ON(group >= EXT4_SB(sb)->s_groups_count);
2791          grp_info = EXT4_SB(sb)->s_group_info;
2792          indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2793          indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2794          return grp_info[indexv][indexh];
2795 }
2796 
2797 /*
2798  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2799  * the locking protocol documented in the comments of ext4_group_add()
2800  * in resize.c
2801  */
2802 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2803 {
2804         ext4_group_t    ngroups = EXT4_SB(sb)->s_groups_count;
2805 
2806         smp_rmb();
2807         return ngroups;
2808 }
2809 
2810 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2811                                              ext4_group_t block_group)
2812 {
2813         return block_group >> sbi->s_log_groups_per_flex;
2814 }
2815 
2816 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2817 {
2818         return 1 << sbi->s_log_groups_per_flex;
2819 }
2820 
2821 #define ext4_std_error(sb, errno)                               \
2822 do {                                                            \
2823         if ((errno))                                            \
2824                 __ext4_std_error((sb), __func__, __LINE__, (errno));    \
2825 } while (0)
2826 
2827 #ifdef CONFIG_SMP
2828 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2829  * counters. So we need to make sure we have free clusters more
2830  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2831  */
2832 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2833 #else
2834 #define EXT4_FREECLUSTERS_WATERMARK 0
2835 #endif
2836 
2837 /* Update i_disksize. Requires i_mutex to avoid races with truncate */
2838 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2839 {
2840         WARN_ON_ONCE(S_ISREG(inode->i_mode) &&
2841                      !inode_is_locked(inode));
2842         down_write(&EXT4_I(inode)->i_data_sem);
2843         if (newsize > EXT4_I(inode)->i_disksize)
2844                 EXT4_I(inode)->i_disksize = newsize;
2845         up_write(&EXT4_I(inode)->i_data_sem);
2846 }
2847 
2848 /* Update i_size, i_disksize. Requires i_mutex to avoid races with truncate */
2849 static inline int ext4_update_inode_size(struct inode *inode, loff_t newsize)
2850 {
2851         int changed = 0;
2852 
2853         if (newsize > inode->i_size) {
2854                 i_size_write(inode, newsize);
2855                 changed = 1;
2856         }
2857         if (newsize > EXT4_I(inode)->i_disksize) {
2858                 ext4_update_i_disksize(inode, newsize);
2859                 changed |= 2;
2860         }
2861         return changed;
2862 }
2863 
2864 int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset,
2865                                       loff_t len);
2866 
2867 struct ext4_group_info {
2868         unsigned long   bb_state;
2869         struct rb_root  bb_free_root;
2870         ext4_grpblk_t   bb_first_free;  /* first free block */
2871         ext4_grpblk_t   bb_free;        /* total free blocks */
2872         ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
2873         ext4_grpblk_t   bb_largest_free_order;/* order of largest frag in BG */
2874         struct          list_head bb_prealloc_list;
2875 #ifdef DOUBLE_CHECK
2876         void            *bb_bitmap;
2877 #endif
2878         struct rw_semaphore alloc_sem;
2879         ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
2880                                          * regions, index is order.
2881                                          * bb_counters[3] = 5 means
2882                                          * 5 free 8-block regions. */
2883 };
2884 
2885 #define EXT4_GROUP_INFO_NEED_INIT_BIT           0
2886 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT         1
2887 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT     2
2888 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT     3
2889 
2890 #define EXT4_MB_GRP_NEED_INIT(grp)      \
2891         (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2892 #define EXT4_MB_GRP_BBITMAP_CORRUPT(grp)        \
2893         (test_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2894 #define EXT4_MB_GRP_IBITMAP_CORRUPT(grp)        \
2895         (test_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2896 
2897 #define EXT4_MB_GRP_WAS_TRIMMED(grp)    \
2898         (test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2899 #define EXT4_MB_GRP_SET_TRIMMED(grp)    \
2900         (set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2901 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)  \
2902         (clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2903 
2904 #define EXT4_MAX_CONTENTION             8
2905 #define EXT4_CONTENTION_THRESHOLD       2
2906 
2907 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2908                                               ext4_group_t group)
2909 {
2910         return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2911 }
2912 
2913 /*
2914  * Returns true if the filesystem is busy enough that attempts to
2915  * access the block group locks has run into contention.
2916  */
2917 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2918 {
2919         return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2920 }
2921 
2922 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2923 {
2924         spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2925         if (spin_trylock(lock))
2926                 /*
2927                  * We're able to grab the lock right away, so drop the
2928                  * lock contention counter.
2929                  */
2930                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2931         else {
2932                 /*
2933                  * The lock is busy, so bump the contention counter,
2934                  * and then wait on the spin lock.
2935                  */
2936                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2937                                   EXT4_MAX_CONTENTION);
2938                 spin_lock(lock);
2939         }
2940 }
2941 
2942 static inline void ext4_unlock_group(struct super_block *sb,
2943                                         ext4_group_t group)
2944 {
2945         spin_unlock(ext4_group_lock_ptr(sb, group));
2946 }
2947 
2948 /*
2949  * Block validity checking
2950  */
2951 #define ext4_check_indirect_blockref(inode, bh)                         \
2952         ext4_check_blockref(__func__, __LINE__, inode,                  \
2953                             (__le32 *)(bh)->b_data,                     \
2954                             EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2955 
2956 #define ext4_ind_check_inode(inode)                                     \
2957         ext4_check_blockref(__func__, __LINE__, inode,                  \
2958                             EXT4_I(inode)->i_data,                      \
2959                             EXT4_NDIR_BLOCKS)
2960 
2961 /*
2962  * Inodes and files operations
2963  */
2964 
2965 /* dir.c */
2966 extern const struct file_operations ext4_dir_operations;
2967 
2968 /* file.c */
2969 extern const struct inode_operations ext4_file_inode_operations;
2970 extern const struct file_operations ext4_file_operations;
2971 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2972 
2973 /* inline.c */
2974 extern int ext4_get_max_inline_size(struct inode *inode);
2975 extern int ext4_find_inline_data_nolock(struct inode *inode);
2976 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
2977                                  unsigned int len);
2978 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
2979 
2980 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
2981 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
2982                                          struct inode *inode,
2983                                          loff_t pos, unsigned len,
2984                                          unsigned flags,
2985                                          struct page **pagep);
2986 extern int ext4_write_inline_data_end(struct inode *inode,
2987                                       loff_t pos, unsigned len,
2988                                       unsigned copied,
2989                                       struct page *page);
2990 extern struct buffer_head *
2991 ext4_journalled_write_inline_data(struct inode *inode,
2992                                   unsigned len,
2993                                   struct page *page);
2994 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
2995                                            struct inode *inode,
2996                                            loff_t pos, unsigned len,
2997                                            unsigned flags,
2998                                            struct page **pagep,
2999                                            void **fsdata);
3000 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
3001                                          unsigned len, unsigned copied,
3002                                          struct page *page);
3003 extern int ext4_try_add_inline_entry(handle_t *handle,
3004                                      struct ext4_filename *fname,
3005                                      struct inode *dir, struct inode *inode);
3006 extern int ext4_try_create_inline_dir(handle_t *handle,
3007                                       struct inode *parent,
3008                                       struct inode *inode);
3009 extern int ext4_read_inline_dir(struct file *filp,
3010                                 struct dir_context *ctx,
3011                                 int *has_inline_data);
3012 extern int htree_inlinedir_to_tree(struct file *dir_file,
3013                                    struct inode *dir, ext4_lblk_t block,
3014                                    struct dx_hash_info *hinfo,
3015                                    __u32 start_hash, __u32 start_minor_hash,
3016                                    int *has_inline_data);
3017 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
3018                                         struct ext4_filename *fname,
3019                                         const struct qstr *d_name,
3020                                         struct ext4_dir_entry_2 **res_dir,
3021                                         int *has_inline_data);
3022 extern int ext4_delete_inline_entry(handle_t *handle,
3023                                     struct inode *dir,
3024                                     struct ext4_dir_entry_2 *de_del,
3025                                     struct buffer_head *bh,
3026                                     int *has_inline_data);
3027 extern bool empty_inline_dir(struct inode *dir, int *has_inline_data);
3028 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
3029                                         struct ext4_dir_entry_2 **parent_de,
3030                                         int *retval);
3031 extern int ext4_inline_data_fiemap(struct inode *inode,
3032                                    struct fiemap_extent_info *fieinfo,
3033                                    int *has_inline, __u64 start, __u64 len);
3034 extern int ext4_try_to_evict_inline_data(handle_t *handle,
3035                                          struct inode *inode,
3036                                          int needed);
3037 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
3038 
3039 extern int ext4_convert_inline_data(struct inode *inode);
3040 
3041 static inline int ext4_has_inline_data(struct inode *inode)
3042 {
3043         return ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) &&
3044                EXT4_I(inode)->i_inline_off;
3045 }
3046 
3047 /* namei.c */
3048 extern const struct inode_operations ext4_dir_inode_operations;
3049 extern const struct inode_operations ext4_special_inode_operations;
3050 extern struct dentry *ext4_get_parent(struct dentry *child);
3051 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
3052                                  struct ext4_dir_entry_2 *de,
3053                                  int blocksize, int csum_size,
3054                                  unsigned int parent_ino, int dotdot_real_len);
3055 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
3056                                    unsigned int blocksize);
3057 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
3058                                          struct inode *inode,
3059                                          struct buffer_head *bh);
3060 #define S_SHIFT 12
3061 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
3062         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
3063         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
3064         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
3065         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
3066         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
3067         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
3068         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
3069 };
3070 
3071 static inline void ext4_set_de_type(struct super_block *sb,
3072                                 struct ext4_dir_entry_2 *de,
3073                                 umode_t mode) {
3074         if (ext4_has_feature_filetype(sb))
3075                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
3076 }
3077 
3078 /* readpages.c */
3079 extern int ext4_mpage_readpages(struct address_space *mapping,
3080                                 struct list_head *pages, struct page *page,
3081                                 unsigned nr_pages);
3082 
3083 /* symlink.c */
3084 extern const struct inode_operations ext4_encrypted_symlink_inode_operations;
3085 extern const struct inode_operations ext4_symlink_inode_operations;
3086 extern const struct inode_operations ext4_fast_symlink_inode_operations;
3087 
3088 /* sysfs.c */
3089 extern int ext4_register_sysfs(struct super_block *sb);
3090 extern void ext4_unregister_sysfs(struct super_block *sb);
3091 extern int __init ext4_init_sysfs(void);
3092 extern void ext4_exit_sysfs(void);
3093 
3094 /* block_validity */
3095 extern void ext4_release_system_zone(struct super_block *sb);
3096 extern int ext4_setup_system_zone(struct super_block *sb);
3097 extern int __init ext4_init_system_zone(void);
3098 extern void ext4_exit_system_zone(void);
3099 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
3100                                  ext4_fsblk_t start_blk,
3101                                  unsigned int count);
3102 extern int ext4_check_blockref(const char *, unsigned int,
3103                                struct inode *, __le32 *, unsigned int);
3104 
3105 /* extents.c */
3106 struct ext4_ext_path;
3107 struct ext4_extent;
3108 
3109 /*
3110  * Maximum number of logical blocks in a file; ext4_extent's ee_block is
3111  * __le32.
3112  */
3113 #define EXT_MAX_BLOCKS  0xffffffff
3114 
3115 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
3116 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
3117 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
3118 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
3119                                struct ext4_map_blocks *map, int flags);
3120 extern int ext4_ext_truncate(handle_t *, struct inode *);
3121 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
3122                                  ext4_lblk_t end);
3123 extern void ext4_ext_init(struct super_block *);
3124 extern void ext4_ext_release(struct super_block *);
3125 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
3126                           loff_t len);
3127 extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
3128                                           loff_t offset, ssize_t len);
3129 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
3130                            struct ext4_map_blocks *map, int flags);
3131 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
3132                                          ext4_lblk_t lblocks);
3133 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
3134                                                    int num,
3135                                                    struct ext4_ext_path *path);
3136 extern int ext4_can_extents_be_merged(struct inode *inode,
3137                                       struct ext4_extent *ex1,
3138                                       struct ext4_extent *ex2);
3139 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
3140                                   struct ext4_ext_path **,
3141                                   struct ext4_extent *, int);
3142 extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
3143                                               struct ext4_ext_path **,
3144                                               int flags);
3145 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
3146 extern int ext4_ext_check_inode(struct inode *inode);
3147 extern int ext4_find_delalloc_range(struct inode *inode,
3148                                     ext4_lblk_t lblk_start,
3149                                     ext4_lblk_t lblk_end);
3150 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
3151 extern ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path);
3152 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3153                         __u64 start, __u64 len);
3154 extern int ext4_ext_precache(struct inode *inode);
3155 extern int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len);
3156 extern int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len);
3157 extern int ext4_swap_extents(handle_t *handle, struct inode *inode1,
3158                                 struct inode *inode2, ext4_lblk_t lblk1,
3159                              ext4_lblk_t lblk2,  ext4_lblk_t count,
3160                              int mark_unwritten,int *err);
3161 
3162 /* move_extent.c */
3163 extern void ext4_double_down_write_data_sem(struct inode *first,
3164                                             struct inode *second);
3165 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
3166                                           struct inode *donor_inode);
3167 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
3168                              __u64 start_orig, __u64 start_donor,
3169                              __u64 len, __u64 *moved_len);
3170 
3171 /* page-io.c */
3172 extern int __init ext4_init_pageio(void);
3173 extern void ext4_exit_pageio(void);
3174 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
3175 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
3176 extern int ext4_put_io_end(ext4_io_end_t *io_end);
3177 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
3178 extern void ext4_io_submit_init(struct ext4_io_submit *io,
3179                                 struct writeback_control *wbc);
3180 extern void ext4_end_io_rsv_work(struct work_struct *work);
3181 extern void ext4_io_submit(struct ext4_io_submit *io);
3182 extern int ext4_bio_write_page(struct ext4_io_submit *io,
3183                                struct page *page,
3184                                int len,
3185                                struct writeback_control *wbc,
3186                                bool keep_towrite);
3187 
3188 /* mmp.c */
3189 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
3190 
3191 /*
3192  * Add new method to test whether block and inode bitmaps are properly
3193  * initialized. With uninit_bg reading the block from disk is not enough
3194  * to mark the bitmap uptodate. We need to also zero-out the bitmap
3195  */
3196 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
3197 
3198 static inline int bitmap_uptodate(struct buffer_head *bh)
3199 {
3200         return (buffer_uptodate(bh) &&
3201                         test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
3202 }
3203 static inline void set_bitmap_uptodate(struct buffer_head *bh)
3204 {
3205         set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
3206 }
3207 
3208 /*
3209  * Disable DIO read nolock optimization, so new dioreaders will be forced
3210  * to grab i_mutex
3211  */
3212 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
3213 {
3214         ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
3215         smp_mb();
3216 }
3217 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
3218 {
3219         smp_mb();
3220         ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
3221 }
3222 
3223 #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
3224 
3225 /* For ioend & aio unwritten conversion wait queues */
3226 #define EXT4_WQ_HASH_SZ         37
3227 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
3228                                             EXT4_WQ_HASH_SZ])
3229 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
3230 
3231 #define EXT4_RESIZING   0
3232 extern int ext4_resize_begin(struct super_block *sb);
3233 extern void ext4_resize_end(struct super_block *sb);
3234 
3235 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
3236                                               struct ext4_io_end *io_end)
3237 {
3238         if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
3239                 io_end->flag |= EXT4_IO_END_UNWRITTEN;
3240                 atomic_inc(&EXT4_I(inode)->i_unwritten);
3241         }
3242 }
3243 
3244 static inline void ext4_clear_io_unwritten_flag(ext4_io_end_t *io_end)
3245 {
3246         struct inode *inode = io_end->inode;
3247 
3248         if (io_end->flag & EXT4_IO_END_UNWRITTEN) {
3249                 io_end->flag &= ~EXT4_IO_END_UNWRITTEN;
3250                 /* Wake up anyone waiting on unwritten extent conversion */
3251                 if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten))
3252                         wake_up_all(ext4_ioend_wq(inode));
3253         }
3254 }
3255 
3256 extern struct iomap_ops ext4_iomap_ops;
3257 
3258 #endif  /* __KERNEL__ */
3259 
3260 #define EFSBADCRC       EBADMSG         /* Bad CRC detected */
3261 #define EFSCORRUPTED    EUCLEAN         /* Filesystem is corrupted */
3262 
3263 #endif  /* _EXT4_H */
3264 

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