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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/falloc.h>
 36 #ifdef __KERNEL__
 37 #include <linux/compat.h>
 38 #endif
 39 
 40 /*
 41  * The fourth extended filesystem constants/structures
 42  */
 43 
 44 /*
 45  * Define EXT4FS_DEBUG to produce debug messages
 46  */
 47 #undef EXT4FS_DEBUG
 48 
 49 /*
 50  * Debug code
 51  */
 52 #ifdef EXT4FS_DEBUG
 53 #define ext4_debug(f, a...)                                             \
 54         do {                                                            \
 55                 printk(KERN_DEBUG "EXT4-fs DEBUG (%s, %d): %s:",        \
 56                         __FILE__, __LINE__, __func__);                  \
 57                 printk(KERN_DEBUG f, ## a);                             \
 58         } while (0)
 59 #else
 60 #define ext4_debug(fmt, ...)    no_printk(fmt, ##__VA_ARGS__)
 61 #endif
 62 
 63 /*
 64  * Turn on EXT_DEBUG to get lots of info about extents operations.
 65  */
 66 #define EXT_DEBUG__
 67 #ifdef EXT_DEBUG
 68 #define ext_debug(fmt, ...)     printk(fmt, ##__VA_ARGS__)
 69 #else
 70 #define ext_debug(fmt, ...)     no_printk(fmt, ##__VA_ARGS__)
 71 #endif
 72 
 73 /* data type for block offset of block group */
 74 typedef int ext4_grpblk_t;
 75 
 76 /* data type for filesystem-wide blocks number */
 77 typedef unsigned long long ext4_fsblk_t;
 78 
 79 /* data type for file logical block number */
 80 typedef __u32 ext4_lblk_t;
 81 
 82 /* data type for block group number */
 83 typedef unsigned int ext4_group_t;
 84 
 85 enum SHIFT_DIRECTION {
 86         SHIFT_LEFT = 0,
 87         SHIFT_RIGHT,
 88 };
 89 
 90 /*
 91  * Flags used in mballoc's allocation_context flags field.
 92  *
 93  * Also used to show what's going on for debugging purposes when the
 94  * flag field is exported via the traceport interface
 95  */
 96 
 97 /* prefer goal again. length */
 98 #define EXT4_MB_HINT_MERGE              0x0001
 99 /* blocks already reserved */
100 #define EXT4_MB_HINT_RESERVED           0x0002
101 /* metadata is being allocated */
102 #define EXT4_MB_HINT_METADATA           0x0004
103 /* first blocks in the file */
104 #define EXT4_MB_HINT_FIRST              0x0008
105 /* search for the best chunk */
106 #define EXT4_MB_HINT_BEST               0x0010
107 /* data is being allocated */
108 #define EXT4_MB_HINT_DATA               0x0020
109 /* don't preallocate (for tails) */
110 #define EXT4_MB_HINT_NOPREALLOC         0x0040
111 /* allocate for locality group */
112 #define EXT4_MB_HINT_GROUP_ALLOC        0x0080
113 /* allocate goal blocks or none */
114 #define EXT4_MB_HINT_GOAL_ONLY          0x0100
115 /* goal is meaningful */
116 #define EXT4_MB_HINT_TRY_GOAL           0x0200
117 /* blocks already pre-reserved by delayed allocation */
118 #define EXT4_MB_DELALLOC_RESERVED       0x0400
119 /* We are doing stream allocation */
120 #define EXT4_MB_STREAM_ALLOC            0x0800
121 /* Use reserved root blocks if needed */
122 #define EXT4_MB_USE_ROOT_BLOCKS         0x1000
123 /* Use blocks from reserved pool */
124 #define EXT4_MB_USE_RESERVED            0x2000
125 
126 struct ext4_allocation_request {
127         /* target inode for block we're allocating */
128         struct inode *inode;
129         /* how many blocks we want to allocate */
130         unsigned int len;
131         /* logical block in target inode */
132         ext4_lblk_t logical;
133         /* the closest logical allocated block to the left */
134         ext4_lblk_t lleft;
135         /* the closest logical allocated block to the right */
136         ext4_lblk_t lright;
137         /* phys. target (a hint) */
138         ext4_fsblk_t goal;
139         /* phys. block for the closest logical allocated block to the left */
140         ext4_fsblk_t pleft;
141         /* phys. block for the closest logical allocated block to the right */
142         ext4_fsblk_t pright;
143         /* flags. see above EXT4_MB_HINT_* */
144         unsigned int flags;
145 };
146 
147 /*
148  * Logical to physical block mapping, used by ext4_map_blocks()
149  *
150  * This structure is used to pass requests into ext4_map_blocks() as
151  * well as to store the information returned by ext4_map_blocks().  It
152  * takes less room on the stack than a struct buffer_head.
153  */
154 #define EXT4_MAP_NEW            (1 << BH_New)
155 #define EXT4_MAP_MAPPED         (1 << BH_Mapped)
156 #define EXT4_MAP_UNWRITTEN      (1 << BH_Unwritten)
157 #define EXT4_MAP_BOUNDARY       (1 << BH_Boundary)
158 #define EXT4_MAP_FLAGS          (EXT4_MAP_NEW | EXT4_MAP_MAPPED |\
159                                  EXT4_MAP_UNWRITTEN | EXT4_MAP_BOUNDARY)
160 
161 struct ext4_map_blocks {
162         ext4_fsblk_t m_pblk;
163         ext4_lblk_t m_lblk;
164         unsigned int m_len;
165         unsigned int m_flags;
166 };
167 
168 /*
169  * Flags for ext4_io_end->flags
170  */
171 #define EXT4_IO_END_UNWRITTEN   0x0001
172 
173 /*
174  * For converting unwritten extents on a work queue. 'handle' is used for
175  * buffered writeback.
176  */
177 typedef struct ext4_io_end {
178         struct list_head        list;           /* per-file finished IO list */
179         handle_t                *handle;        /* handle reserved for extent
180                                                  * conversion */
181         struct inode            *inode;         /* file being written to */
182         struct bio              *bio;           /* Linked list of completed
183                                                  * bios covering the extent */
184         unsigned int            flag;           /* unwritten or not */
185         loff_t                  offset;         /* offset in the file */
186         ssize_t                 size;           /* size of the extent */
187         atomic_t                count;          /* reference counter */
188 } ext4_io_end_t;
189 
190 struct ext4_io_submit {
191         struct writeback_control *io_wbc;
192         struct bio              *io_bio;
193         ext4_io_end_t           *io_end;
194         sector_t                io_next_block;
195 };
196 
197 /*
198  * Special inodes numbers
199  */
200 #define EXT4_BAD_INO             1      /* Bad blocks inode */
201 #define EXT4_ROOT_INO            2      /* Root inode */
202 #define EXT4_USR_QUOTA_INO       3      /* User quota inode */
203 #define EXT4_GRP_QUOTA_INO       4      /* Group quota inode */
204 #define EXT4_BOOT_LOADER_INO     5      /* Boot loader inode */
205 #define EXT4_UNDEL_DIR_INO       6      /* Undelete directory inode */
206 #define EXT4_RESIZE_INO          7      /* Reserved group descriptors inode */
207 #define EXT4_JOURNAL_INO         8      /* Journal inode */
208 
209 /* First non-reserved inode for old ext4 filesystems */
210 #define EXT4_GOOD_OLD_FIRST_INO 11
211 
212 /*
213  * Maximal count of links to a file
214  */
215 #define EXT4_LINK_MAX           65000
216 
217 /*
218  * Macro-instructions used to manage several block sizes
219  */
220 #define EXT4_MIN_BLOCK_SIZE             1024
221 #define EXT4_MAX_BLOCK_SIZE             65536
222 #define EXT4_MIN_BLOCK_LOG_SIZE         10
223 #define EXT4_MAX_BLOCK_LOG_SIZE         16
224 #ifdef __KERNEL__
225 # define EXT4_BLOCK_SIZE(s)             ((s)->s_blocksize)
226 #else
227 # define EXT4_BLOCK_SIZE(s)             (EXT4_MIN_BLOCK_SIZE << (s)->s_log_block_size)
228 #endif
229 #define EXT4_ADDR_PER_BLOCK(s)          (EXT4_BLOCK_SIZE(s) / sizeof(__u32))
230 #define EXT4_CLUSTER_SIZE(s)            (EXT4_BLOCK_SIZE(s) << \
231                                          EXT4_SB(s)->s_cluster_bits)
232 #ifdef __KERNEL__
233 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_blocksize_bits)
234 # define EXT4_CLUSTER_BITS(s)           (EXT4_SB(s)->s_cluster_bits)
235 #else
236 # define EXT4_BLOCK_SIZE_BITS(s)        ((s)->s_log_block_size + 10)
237 #endif
238 #ifdef __KERNEL__
239 #define EXT4_ADDR_PER_BLOCK_BITS(s)     (EXT4_SB(s)->s_addr_per_block_bits)
240 #define EXT4_INODE_SIZE(s)              (EXT4_SB(s)->s_inode_size)
241 #define EXT4_FIRST_INO(s)               (EXT4_SB(s)->s_first_ino)
242 #else
243 #define EXT4_INODE_SIZE(s)      (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
244                                  EXT4_GOOD_OLD_INODE_SIZE : \
245                                  (s)->s_inode_size)
246 #define EXT4_FIRST_INO(s)       (((s)->s_rev_level == EXT4_GOOD_OLD_REV) ? \
247                                  EXT4_GOOD_OLD_FIRST_INO : \
248                                  (s)->s_first_ino)
249 #endif
250 #define EXT4_BLOCK_ALIGN(size, blkbits)         ALIGN((size), (1 << (blkbits)))
251 
252 /* Translate a block number to a cluster number */
253 #define EXT4_B2C(sbi, blk)      ((blk) >> (sbi)->s_cluster_bits)
254 /* Translate a cluster number to a block number */
255 #define EXT4_C2B(sbi, cluster)  ((cluster) << (sbi)->s_cluster_bits)
256 /* Translate # of blks to # of clusters */
257 #define EXT4_NUM_B2C(sbi, blks) (((blks) + (sbi)->s_cluster_ratio - 1) >> \
258                                  (sbi)->s_cluster_bits)
259 /* Mask out the low bits to get the starting block of the cluster */
260 #define EXT4_PBLK_CMASK(s, pblk) ((pblk) &                              \
261                                   ~((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
262 #define EXT4_LBLK_CMASK(s, lblk) ((lblk) &                              \
263                                   ~((ext4_lblk_t) (s)->s_cluster_ratio - 1))
264 /* Get the cluster offset */
265 #define EXT4_PBLK_COFF(s, pblk) ((pblk) &                               \
266                                  ((ext4_fsblk_t) (s)->s_cluster_ratio - 1))
267 #define EXT4_LBLK_COFF(s, lblk) ((lblk) &                               \
268                                  ((ext4_lblk_t) (s)->s_cluster_ratio - 1))
269 
270 /*
271  * Structure of a blocks group descriptor
272  */
273 struct ext4_group_desc
274 {
275         __le32  bg_block_bitmap_lo;     /* Blocks bitmap block */
276         __le32  bg_inode_bitmap_lo;     /* Inodes bitmap block */
277         __le32  bg_inode_table_lo;      /* Inodes table block */
278         __le16  bg_free_blocks_count_lo;/* Free blocks count */
279         __le16  bg_free_inodes_count_lo;/* Free inodes count */
280         __le16  bg_used_dirs_count_lo;  /* Directories count */
281         __le16  bg_flags;               /* EXT4_BG_flags (INODE_UNINIT, etc) */
282         __le32  bg_exclude_bitmap_lo;   /* Exclude bitmap for snapshots */
283         __le16  bg_block_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+bbitmap) LE */
284         __le16  bg_inode_bitmap_csum_lo;/* crc32c(s_uuid+grp_num+ibitmap) LE */
285         __le16  bg_itable_unused_lo;    /* Unused inodes count */
286         __le16  bg_checksum;            /* crc16(sb_uuid+group+desc) */
287         __le32  bg_block_bitmap_hi;     /* Blocks bitmap block MSB */
288         __le32  bg_inode_bitmap_hi;     /* Inodes bitmap block MSB */
289         __le32  bg_inode_table_hi;      /* Inodes table block MSB */
290         __le16  bg_free_blocks_count_hi;/* Free blocks count MSB */
291         __le16  bg_free_inodes_count_hi;/* Free inodes count MSB */
292         __le16  bg_used_dirs_count_hi;  /* Directories count MSB */
293         __le16  bg_itable_unused_hi;    /* Unused inodes count MSB */
294         __le32  bg_exclude_bitmap_hi;   /* Exclude bitmap block MSB */
295         __le16  bg_block_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+bbitmap) BE */
296         __le16  bg_inode_bitmap_csum_hi;/* crc32c(s_uuid+grp_num+ibitmap) BE */
297         __u32   bg_reserved;
298 };
299 
300 #define EXT4_BG_INODE_BITMAP_CSUM_HI_END        \
301         (offsetof(struct ext4_group_desc, bg_inode_bitmap_csum_hi) + \
302          sizeof(__le16))
303 #define EXT4_BG_BLOCK_BITMAP_CSUM_HI_END        \
304         (offsetof(struct ext4_group_desc, bg_block_bitmap_csum_hi) + \
305          sizeof(__le16))
306 
307 /*
308  * Structure of a flex block group info
309  */
310 
311 struct flex_groups {
312         atomic64_t      free_clusters;
313         atomic_t        free_inodes;
314         atomic_t        used_dirs;
315 };
316 
317 #define EXT4_BG_INODE_UNINIT    0x0001 /* Inode table/bitmap not in use */
318 #define EXT4_BG_BLOCK_UNINIT    0x0002 /* Block bitmap not in use */
319 #define EXT4_BG_INODE_ZEROED    0x0004 /* On-disk itable initialized to zero */
320 
321 /*
322  * Macro-instructions used to manage group descriptors
323  */
324 #define EXT4_MIN_DESC_SIZE              32
325 #define EXT4_MIN_DESC_SIZE_64BIT        64
326 #define EXT4_MAX_DESC_SIZE              EXT4_MIN_BLOCK_SIZE
327 #define EXT4_DESC_SIZE(s)               (EXT4_SB(s)->s_desc_size)
328 #ifdef __KERNEL__
329 # define EXT4_BLOCKS_PER_GROUP(s)       (EXT4_SB(s)->s_blocks_per_group)
330 # define EXT4_CLUSTERS_PER_GROUP(s)     (EXT4_SB(s)->s_clusters_per_group)
331 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_SB(s)->s_desc_per_block)
332 # define EXT4_INODES_PER_GROUP(s)       (EXT4_SB(s)->s_inodes_per_group)
333 # define EXT4_DESC_PER_BLOCK_BITS(s)    (EXT4_SB(s)->s_desc_per_block_bits)
334 #else
335 # define EXT4_BLOCKS_PER_GROUP(s)       ((s)->s_blocks_per_group)
336 # define EXT4_DESC_PER_BLOCK(s)         (EXT4_BLOCK_SIZE(s) / EXT4_DESC_SIZE(s))
337 # define EXT4_INODES_PER_GROUP(s)       ((s)->s_inodes_per_group)
338 #endif
339 
340 /*
341  * Constants relative to the data blocks
342  */
343 #define EXT4_NDIR_BLOCKS                12
344 #define EXT4_IND_BLOCK                  EXT4_NDIR_BLOCKS
345 #define EXT4_DIND_BLOCK                 (EXT4_IND_BLOCK + 1)
346 #define EXT4_TIND_BLOCK                 (EXT4_DIND_BLOCK + 1)
347 #define EXT4_N_BLOCKS                   (EXT4_TIND_BLOCK + 1)
348 
349 /*
350  * Inode flags
351  */
352 #define EXT4_SECRM_FL                   0x00000001 /* Secure deletion */
353 #define EXT4_UNRM_FL                    0x00000002 /* Undelete */
354 #define EXT4_COMPR_FL                   0x00000004 /* Compress file */
355 #define EXT4_SYNC_FL                    0x00000008 /* Synchronous updates */
356 #define EXT4_IMMUTABLE_FL               0x00000010 /* Immutable file */
357 #define EXT4_APPEND_FL                  0x00000020 /* writes to file may only append */
358 #define EXT4_NODUMP_FL                  0x00000040 /* do not dump file */
359 #define EXT4_NOATIME_FL                 0x00000080 /* do not update atime */
360 /* Reserved for compression usage... */
361 #define EXT4_DIRTY_FL                   0x00000100
362 #define EXT4_COMPRBLK_FL                0x00000200 /* One or more compressed clusters */
363 #define EXT4_NOCOMPR_FL                 0x00000400 /* Don't compress */
364         /* nb: was previously EXT2_ECOMPR_FL */
365 #define EXT4_ENCRYPT_FL                 0x00000800 /* encrypted file */
366 /* End compression flags --- maybe not all used */
367 #define EXT4_INDEX_FL                   0x00001000 /* hash-indexed directory */
368 #define EXT4_IMAGIC_FL                  0x00002000 /* AFS directory */
369 #define EXT4_JOURNAL_DATA_FL            0x00004000 /* file data should be journaled */
370 #define EXT4_NOTAIL_FL                  0x00008000 /* file tail should not be merged */
371 #define EXT4_DIRSYNC_FL                 0x00010000 /* dirsync behaviour (directories only) */
372 #define EXT4_TOPDIR_FL                  0x00020000 /* Top of directory hierarchies*/
373 #define EXT4_HUGE_FILE_FL               0x00040000 /* Set to each huge file */
374 #define EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
375 #define EXT4_EA_INODE_FL                0x00200000 /* Inode used for large EA */
376 #define EXT4_EOFBLOCKS_FL               0x00400000 /* Blocks allocated beyond EOF */
377 #define EXT4_INLINE_DATA_FL             0x10000000 /* Inode has inline data. */
378 #define EXT4_PROJINHERIT_FL             0x20000000 /* Create with parents projid */
379 #define EXT4_RESERVED_FL                0x80000000 /* reserved for ext4 lib */
380 
381 #define EXT4_FL_USER_VISIBLE            0x004BDFFF /* User visible flags */
382 #define EXT4_FL_USER_MODIFIABLE         0x004380FF /* User modifiable flags */
383 
384 /* Flags that should be inherited by new inodes from their parent. */
385 #define EXT4_FL_INHERITED (EXT4_SECRM_FL | EXT4_UNRM_FL | EXT4_COMPR_FL |\
386                            EXT4_SYNC_FL | EXT4_NODUMP_FL | EXT4_NOATIME_FL |\
387                            EXT4_NOCOMPR_FL | EXT4_JOURNAL_DATA_FL |\
388                            EXT4_NOTAIL_FL | EXT4_DIRSYNC_FL)
389 
390 /* Flags that are appropriate for regular files (all but dir-specific ones). */
391 #define EXT4_REG_FLMASK (~(EXT4_DIRSYNC_FL | EXT4_TOPDIR_FL))
392 
393 /* Flags that are appropriate for non-directories/regular files. */
394 #define EXT4_OTHER_FLMASK (EXT4_NODUMP_FL | EXT4_NOATIME_FL)
395 
396 /* Mask out flags that are inappropriate for the given type of inode. */
397 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
398 {
399         if (S_ISDIR(mode))
400                 return flags;
401         else if (S_ISREG(mode))
402                 return flags & EXT4_REG_FLMASK;
403         else
404                 return flags & EXT4_OTHER_FLMASK;
405 }
406 
407 /*
408  * Inode flags used for atomic set/get
409  */
410 enum {
411         EXT4_INODE_SECRM        = 0,    /* Secure deletion */
412         EXT4_INODE_UNRM         = 1,    /* Undelete */
413         EXT4_INODE_COMPR        = 2,    /* Compress file */
414         EXT4_INODE_SYNC         = 3,    /* Synchronous updates */
415         EXT4_INODE_IMMUTABLE    = 4,    /* Immutable file */
416         EXT4_INODE_APPEND       = 5,    /* writes to file may only append */
417         EXT4_INODE_NODUMP       = 6,    /* do not dump file */
418         EXT4_INODE_NOATIME      = 7,    /* do not update atime */
419 /* Reserved for compression usage... */
420         EXT4_INODE_DIRTY        = 8,
421         EXT4_INODE_COMPRBLK     = 9,    /* One or more compressed clusters */
422         EXT4_INODE_NOCOMPR      = 10,   /* Don't compress */
423         EXT4_INODE_ENCRYPT      = 11,   /* Encrypted file */
424 /* End compression flags --- maybe not all used */
425         EXT4_INODE_INDEX        = 12,   /* hash-indexed directory */
426         EXT4_INODE_IMAGIC       = 13,   /* AFS directory */
427         EXT4_INODE_JOURNAL_DATA = 14,   /* file data should be journaled */
428         EXT4_INODE_NOTAIL       = 15,   /* file tail should not be merged */
429         EXT4_INODE_DIRSYNC      = 16,   /* dirsync behaviour (directories only) */
430         EXT4_INODE_TOPDIR       = 17,   /* Top of directory hierarchies*/
431         EXT4_INODE_HUGE_FILE    = 18,   /* Set to each huge file */
432         EXT4_INODE_EXTENTS      = 19,   /* Inode uses extents */
433         EXT4_INODE_EA_INODE     = 21,   /* Inode used for large EA */
434         EXT4_INODE_EOFBLOCKS    = 22,   /* Blocks allocated beyond EOF */
435         EXT4_INODE_INLINE_DATA  = 28,   /* Data in inode. */
436         EXT4_INODE_PROJINHERIT  = 29,   /* Create with parents projid */
437         EXT4_INODE_RESERVED     = 31,   /* reserved for ext4 lib */
438 };
439 
440 /*
441  * Since it's pretty easy to mix up bit numbers and hex values, we use a
442  * build-time check to make sure that EXT4_XXX_FL is consistent with respect to
443  * EXT4_INODE_XXX. If all is well, the macros will be dropped, so, it won't cost
444  * any extra space in the compiled kernel image, otherwise, the build will fail.
445  * It's important that these values are the same, since we are using
446  * EXT4_INODE_XXX to test for flag values, but EXT4_XXX_FL must be consistent
447  * with the values of FS_XXX_FL defined in include/linux/fs.h and the on-disk
448  * values found in ext2, ext3 and ext4 filesystems, and of course the values
449  * defined in e2fsprogs.
450  *
451  * It's not paranoia if the Murphy's Law really *is* out to get you.  :-)
452  */
453 #define TEST_FLAG_VALUE(FLAG) (EXT4_##FLAG##_FL == (1 << EXT4_INODE_##FLAG))
454 #define CHECK_FLAG_VALUE(FLAG) BUILD_BUG_ON(!TEST_FLAG_VALUE(FLAG))
455 
456 static inline void ext4_check_flag_values(void)
457 {
458         CHECK_FLAG_VALUE(SECRM);
459         CHECK_FLAG_VALUE(UNRM);
460         CHECK_FLAG_VALUE(COMPR);
461         CHECK_FLAG_VALUE(SYNC);
462         CHECK_FLAG_VALUE(IMMUTABLE);
463         CHECK_FLAG_VALUE(APPEND);
464         CHECK_FLAG_VALUE(NODUMP);
465         CHECK_FLAG_VALUE(NOATIME);
466         CHECK_FLAG_VALUE(DIRTY);
467         CHECK_FLAG_VALUE(COMPRBLK);
468         CHECK_FLAG_VALUE(NOCOMPR);
469         CHECK_FLAG_VALUE(ENCRYPT);
470         CHECK_FLAG_VALUE(INDEX);
471         CHECK_FLAG_VALUE(IMAGIC);
472         CHECK_FLAG_VALUE(JOURNAL_DATA);
473         CHECK_FLAG_VALUE(NOTAIL);
474         CHECK_FLAG_VALUE(DIRSYNC);
475         CHECK_FLAG_VALUE(TOPDIR);
476         CHECK_FLAG_VALUE(HUGE_FILE);
477         CHECK_FLAG_VALUE(EXTENTS);
478         CHECK_FLAG_VALUE(EA_INODE);
479         CHECK_FLAG_VALUE(EOFBLOCKS);
480         CHECK_FLAG_VALUE(INLINE_DATA);
481         CHECK_FLAG_VALUE(PROJINHERIT);
482         CHECK_FLAG_VALUE(RESERVED);
483 }
484 
485 /* Used to pass group descriptor data when online resize is done */
486 struct ext4_new_group_input {
487         __u32 group;            /* Group number for this data */
488         __u64 block_bitmap;     /* Absolute block number of block bitmap */
489         __u64 inode_bitmap;     /* Absolute block number of inode bitmap */
490         __u64 inode_table;      /* Absolute block number of inode table start */
491         __u32 blocks_count;     /* Total number of blocks in this group */
492         __u16 reserved_blocks;  /* Number of reserved blocks in this group */
493         __u16 unused;
494 };
495 
496 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
497 struct compat_ext4_new_group_input {
498         u32 group;
499         compat_u64 block_bitmap;
500         compat_u64 inode_bitmap;
501         compat_u64 inode_table;
502         u32 blocks_count;
503         u16 reserved_blocks;
504         u16 unused;
505 };
506 #endif
507 
508 /* The struct ext4_new_group_input in kernel space, with free_blocks_count */
509 struct ext4_new_group_data {
510         __u32 group;
511         __u64 block_bitmap;
512         __u64 inode_bitmap;
513         __u64 inode_table;
514         __u32 blocks_count;
515         __u16 reserved_blocks;
516         __u16 unused;
517         __u32 free_blocks_count;
518 };
519 
520 /* Indexes used to index group tables in ext4_new_group_data */
521 enum {
522         BLOCK_BITMAP = 0,       /* block bitmap */
523         INODE_BITMAP,           /* inode bitmap */
524         INODE_TABLE,            /* inode tables */
525         GROUP_TABLE_COUNT,
526 };
527 
528 /*
529  * Flags used by ext4_map_blocks()
530  */
531         /* Allocate any needed blocks and/or convert an unwritten
532            extent to be an initialized ext4 */
533 #define EXT4_GET_BLOCKS_CREATE                  0x0001
534         /* Request the creation of an unwritten extent */
535 #define EXT4_GET_BLOCKS_UNWRIT_EXT              0x0002
536 #define EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT       (EXT4_GET_BLOCKS_UNWRIT_EXT|\
537                                                  EXT4_GET_BLOCKS_CREATE)
538         /* Caller is from the delayed allocation writeout path
539          * finally doing the actual allocation of delayed blocks */
540 #define EXT4_GET_BLOCKS_DELALLOC_RESERVE        0x0004
541         /* caller is from the direct IO path, request to creation of an
542         unwritten extents if not allocated, split the unwritten
543         extent if blocks has been preallocated already*/
544 #define EXT4_GET_BLOCKS_PRE_IO                  0x0008
545 #define EXT4_GET_BLOCKS_CONVERT                 0x0010
546 #define EXT4_GET_BLOCKS_IO_CREATE_EXT           (EXT4_GET_BLOCKS_PRE_IO|\
547                                          EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
548         /* Convert extent to initialized after IO complete */
549 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT          (EXT4_GET_BLOCKS_CONVERT|\
550                                          EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT)
551         /* Eventual metadata allocation (due to growing extent tree)
552          * should not fail, so try to use reserved blocks for that.*/
553 #define EXT4_GET_BLOCKS_METADATA_NOFAIL         0x0020
554         /* Don't normalize allocation size (used for fallocate) */
555 #define EXT4_GET_BLOCKS_NO_NORMALIZE            0x0040
556         /* Request will not result in inode size update (user for fallocate) */
557 #define EXT4_GET_BLOCKS_KEEP_SIZE               0x0080
558         /* Do not take i_data_sem locking in ext4_map_blocks */
559 #define EXT4_GET_BLOCKS_NO_LOCK                 0x0100
560         /* Convert written extents to unwritten */
561 #define EXT4_GET_BLOCKS_CONVERT_UNWRITTEN       0x0200
562 
563 /*
564  * The bit position of these flags must not overlap with any of the
565  * EXT4_GET_BLOCKS_*.  They are used by ext4_find_extent(),
566  * read_extent_tree_block(), ext4_split_extent_at(),
567  * ext4_ext_insert_extent(), and ext4_ext_create_new_leaf().
568  * EXT4_EX_NOCACHE is used to indicate that the we shouldn't be
569  * caching the extents when reading from the extent tree while a
570  * truncate or punch hole operation is in progress.
571  */
572 #define EXT4_EX_NOCACHE                         0x40000000
573 #define EXT4_EX_FORCE_CACHE                     0x20000000
574 
575 /*
576  * Flags used by ext4_free_blocks
577  */
578 #define EXT4_FREE_BLOCKS_METADATA       0x0001
579 #define EXT4_FREE_BLOCKS_FORGET         0x0002
580 #define EXT4_FREE_BLOCKS_VALIDATED      0x0004
581 #define EXT4_FREE_BLOCKS_NO_QUOT_UPDATE 0x0008
582 #define EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER   0x0010
583 #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER    0x0020
584 
585 /* Encryption algorithms */
586 #define EXT4_ENCRYPTION_MODE_INVALID            0
587 #define EXT4_ENCRYPTION_MODE_AES_256_XTS        1
588 #define EXT4_ENCRYPTION_MODE_AES_256_GCM        2
589 #define EXT4_ENCRYPTION_MODE_AES_256_CBC        3
590 #define EXT4_ENCRYPTION_MODE_AES_256_CTS        4
591 
592 #include "ext4_crypto.h"
593 
594 /*
595  * ioctl commands
596  */
597 #define EXT4_IOC_GETFLAGS               FS_IOC_GETFLAGS
598 #define EXT4_IOC_SETFLAGS               FS_IOC_SETFLAGS
599 #define EXT4_IOC_GETVERSION             _IOR('f', 3, long)
600 #define EXT4_IOC_SETVERSION             _IOW('f', 4, long)
601 #define EXT4_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
602 #define EXT4_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
603 #define EXT4_IOC_GETRSVSZ               _IOR('f', 5, long)
604 #define EXT4_IOC_SETRSVSZ               _IOW('f', 6, long)
605 #define EXT4_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
606 #define EXT4_IOC_GROUP_ADD              _IOW('f', 8, struct ext4_new_group_input)
607 #define EXT4_IOC_MIGRATE                _IO('f', 9)
608  /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
609  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
610 #define EXT4_IOC_ALLOC_DA_BLKS          _IO('f', 12)
611 #define EXT4_IOC_MOVE_EXT               _IOWR('f', 15, struct move_extent)
612 #define EXT4_IOC_RESIZE_FS              _IOW('f', 16, __u64)
613 #define EXT4_IOC_SWAP_BOOT              _IO('f', 17)
614 #define EXT4_IOC_PRECACHE_EXTENTS       _IO('f', 18)
615 #define EXT4_IOC_SET_ENCRYPTION_POLICY  _IOR('f', 19, struct ext4_encryption_policy)
616 #define EXT4_IOC_GET_ENCRYPTION_PWSALT  _IOW('f', 20, __u8[16])
617 #define EXT4_IOC_GET_ENCRYPTION_POLICY  _IOW('f', 21, struct ext4_encryption_policy)
618 
619 #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
620 /*
621  * ioctl commands in 32 bit emulation
622  */
623 #define EXT4_IOC32_GETFLAGS             FS_IOC32_GETFLAGS
624 #define EXT4_IOC32_SETFLAGS             FS_IOC32_SETFLAGS
625 #define EXT4_IOC32_GETVERSION           _IOR('f', 3, int)
626 #define EXT4_IOC32_SETVERSION           _IOW('f', 4, int)
627 #define EXT4_IOC32_GETRSVSZ             _IOR('f', 5, int)
628 #define EXT4_IOC32_SETRSVSZ             _IOW('f', 6, int)
629 #define EXT4_IOC32_GROUP_EXTEND         _IOW('f', 7, unsigned int)
630 #define EXT4_IOC32_GROUP_ADD            _IOW('f', 8, struct compat_ext4_new_group_input)
631 #define EXT4_IOC32_GETVERSION_OLD       FS_IOC32_GETVERSION
632 #define EXT4_IOC32_SETVERSION_OLD       FS_IOC32_SETVERSION
633 #endif
634 
635 /* Max physical block we can address w/o extents */
636 #define EXT4_MAX_BLOCK_FILE_PHYS        0xFFFFFFFF
637 
638 /*
639  * Structure of an inode on the disk
640  */
641 struct ext4_inode {
642         __le16  i_mode;         /* File mode */
643         __le16  i_uid;          /* Low 16 bits of Owner Uid */
644         __le32  i_size_lo;      /* Size in bytes */
645         __le32  i_atime;        /* Access time */
646         __le32  i_ctime;        /* Inode Change time */
647         __le32  i_mtime;        /* Modification time */
648         __le32  i_dtime;        /* Deletion Time */
649         __le16  i_gid;          /* Low 16 bits of Group Id */
650         __le16  i_links_count;  /* Links count */
651         __le32  i_blocks_lo;    /* Blocks count */
652         __le32  i_flags;        /* File flags */
653         union {
654                 struct {
655                         __le32  l_i_version;
656                 } linux1;
657                 struct {
658                         __u32  h_i_translator;
659                 } hurd1;
660                 struct {
661                         __u32  m_i_reserved1;
662                 } masix1;
663         } osd1;                         /* OS dependent 1 */
664         __le32  i_block[EXT4_N_BLOCKS];/* Pointers to blocks */
665         __le32  i_generation;   /* File version (for NFS) */
666         __le32  i_file_acl_lo;  /* File ACL */
667         __le32  i_size_high;
668         __le32  i_obso_faddr;   /* Obsoleted fragment address */
669         union {
670                 struct {
671                         __le16  l_i_blocks_high; /* were l_i_reserved1 */
672                         __le16  l_i_file_acl_high;
673                         __le16  l_i_uid_high;   /* these 2 fields */
674                         __le16  l_i_gid_high;   /* were reserved2[0] */
675                         __le16  l_i_checksum_lo;/* crc32c(uuid+inum+inode) LE */
676                         __le16  l_i_reserved;
677                 } linux2;
678                 struct {
679                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
680                         __u16   h_i_mode_high;
681                         __u16   h_i_uid_high;
682                         __u16   h_i_gid_high;
683                         __u32   h_i_author;
684                 } hurd2;
685                 struct {
686                         __le16  h_i_reserved1;  /* Obsoleted fragment number/size which are removed in ext4 */
687                         __le16  m_i_file_acl_high;
688                         __u32   m_i_reserved2[2];
689                 } masix2;
690         } osd2;                         /* OS dependent 2 */
691         __le16  i_extra_isize;
692         __le16  i_checksum_hi;  /* crc32c(uuid+inum+inode) BE */
693         __le32  i_ctime_extra;  /* extra Change time      (nsec << 2 | epoch) */
694         __le32  i_mtime_extra;  /* extra Modification time(nsec << 2 | epoch) */
695         __le32  i_atime_extra;  /* extra Access time      (nsec << 2 | epoch) */
696         __le32  i_crtime;       /* File Creation time */
697         __le32  i_crtime_extra; /* extra FileCreationtime (nsec << 2 | epoch) */
698         __le32  i_version_hi;   /* high 32 bits for 64-bit version */
699         __le32  i_projid;       /* Project ID */
700 };
701 
702 struct move_extent {
703         __u32 reserved;         /* should be zero */
704         __u32 donor_fd;         /* donor file descriptor */
705         __u64 orig_start;       /* logical start offset in block for orig */
706         __u64 donor_start;      /* logical start offset in block for donor */
707         __u64 len;              /* block length to be moved */
708         __u64 moved_len;        /* moved block length */
709 };
710 
711 #define EXT4_EPOCH_BITS 2
712 #define EXT4_EPOCH_MASK ((1 << EXT4_EPOCH_BITS) - 1)
713 #define EXT4_NSEC_MASK  (~0UL << EXT4_EPOCH_BITS)
714 
715 /*
716  * Extended fields will fit into an inode if the filesystem was formatted
717  * with large inodes (-I 256 or larger) and there are not currently any EAs
718  * consuming all of the available space. For new inodes we always reserve
719  * enough space for the kernel's known extended fields, but for inodes
720  * created with an old kernel this might not have been the case. None of
721  * the extended inode fields is critical for correct filesystem operation.
722  * This macro checks if a certain field fits in the inode. Note that
723  * inode-size = GOOD_OLD_INODE_SIZE + i_extra_isize
724  */
725 #define EXT4_FITS_IN_INODE(ext4_inode, einode, field)   \
726         ((offsetof(typeof(*ext4_inode), field) +        \
727           sizeof((ext4_inode)->field))                  \
728         <= (EXT4_GOOD_OLD_INODE_SIZE +                  \
729             (einode)->i_extra_isize))                   \
730 
731 /*
732  * We use an encoding that preserves the times for extra epoch "00":
733  *
734  * extra  msb of                         adjust for signed
735  * epoch  32-bit                         32-bit tv_sec to
736  * bits   time    decoded 64-bit tv_sec  64-bit tv_sec      valid time range
737  * 0 0    1    -0x80000000..-0x00000001  0x000000000 1901-12-13..1969-12-31
738  * 0 0    0    0x000000000..0x07fffffff  0x000000000 1970-01-01..2038-01-19
739  * 0 1    1    0x080000000..0x0ffffffff  0x100000000 2038-01-19..2106-02-07
740  * 0 1    0    0x100000000..0x17fffffff  0x100000000 2106-02-07..2174-02-25
741  * 1 0    1    0x180000000..0x1ffffffff  0x200000000 2174-02-25..2242-03-16
742  * 1 0    0    0x200000000..0x27fffffff  0x200000000 2242-03-16..2310-04-04
743  * 1 1    1    0x280000000..0x2ffffffff  0x300000000 2310-04-04..2378-04-22
744  * 1 1    0    0x300000000..0x37fffffff  0x300000000 2378-04-22..2446-05-10
745  *
746  * Note that previous versions of the kernel on 64-bit systems would
747  * incorrectly use extra epoch bits 1,1 for dates between 1901 and
748  * 1970.  e2fsck will correct this, assuming that it is run on the
749  * affected filesystem before 2242.
750  */
751 
752 static inline __le32 ext4_encode_extra_time(struct timespec *time)
753 {
754         u32 extra = sizeof(time->tv_sec) > 4 ?
755                 ((time->tv_sec - (s32)time->tv_sec) >> 32) & EXT4_EPOCH_MASK : 0;
756         return cpu_to_le32(extra | (time->tv_nsec << EXT4_EPOCH_BITS));
757 }
758 
759 static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
760 {
761         if (unlikely(sizeof(time->tv_sec) > 4 &&
762                         (extra & cpu_to_le32(EXT4_EPOCH_MASK)))) {
763 #if LINUX_VERSION_CODE < KERNEL_VERSION(4,20,0)
764                 /* Handle legacy encoding of pre-1970 dates with epoch
765                  * bits 1,1.  We assume that by kernel version 4.20,
766                  * everyone will have run fsck over the affected
767                  * filesystems to correct the problem.  (This
768                  * backwards compatibility may be removed before this
769                  * time, at the discretion of the ext4 developers.)
770                  */
771                 u64 extra_bits = le32_to_cpu(extra) & EXT4_EPOCH_MASK;
772                 if (extra_bits == 3 && ((time->tv_sec) & 0x80000000) != 0)
773                         extra_bits = 0;
774                 time->tv_sec += extra_bits << 32;
775 #else
776                 time->tv_sec += (u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK) << 32;
777 #endif
778         }
779         time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
780 }
781 
782 #define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode)                          \
783 do {                                                                           \
784         (raw_inode)->xtime = cpu_to_le32((inode)->xtime.tv_sec);               \
785         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
786                 (raw_inode)->xtime ## _extra =                                 \
787                                 ext4_encode_extra_time(&(inode)->xtime);       \
788 } while (0)
789 
790 #define EXT4_EINODE_SET_XTIME(xtime, einode, raw_inode)                        \
791 do {                                                                           \
792         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
793                 (raw_inode)->xtime = cpu_to_le32((einode)->xtime.tv_sec);      \
794         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
795                 (raw_inode)->xtime ## _extra =                                 \
796                                 ext4_encode_extra_time(&(einode)->xtime);      \
797 } while (0)
798 
799 #define EXT4_INODE_GET_XTIME(xtime, inode, raw_inode)                          \
800 do {                                                                           \
801         (inode)->xtime.tv_sec = (signed)le32_to_cpu((raw_inode)->xtime);       \
802         if (EXT4_FITS_IN_INODE(raw_inode, EXT4_I(inode), xtime ## _extra))     \
803                 ext4_decode_extra_time(&(inode)->xtime,                        \
804                                        raw_inode->xtime ## _extra);            \
805         else                                                                   \
806                 (inode)->xtime.tv_nsec = 0;                                    \
807 } while (0)
808 
809 #define EXT4_EINODE_GET_XTIME(xtime, einode, raw_inode)                        \
810 do {                                                                           \
811         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime))                      \
812                 (einode)->xtime.tv_sec =                                       \
813                         (signed)le32_to_cpu((raw_inode)->xtime);               \
814         else                                                                   \
815                 (einode)->xtime.tv_sec = 0;                                    \
816         if (EXT4_FITS_IN_INODE(raw_inode, einode, xtime ## _extra))            \
817                 ext4_decode_extra_time(&(einode)->xtime,                       \
818                                        raw_inode->xtime ## _extra);            \
819         else                                                                   \
820                 (einode)->xtime.tv_nsec = 0;                                   \
821 } while (0)
822 
823 #define i_disk_version osd1.linux1.l_i_version
824 
825 #if defined(__KERNEL__) || defined(__linux__)
826 #define i_reserved1     osd1.linux1.l_i_reserved1
827 #define i_file_acl_high osd2.linux2.l_i_file_acl_high
828 #define i_blocks_high   osd2.linux2.l_i_blocks_high
829 #define i_uid_low       i_uid
830 #define i_gid_low       i_gid
831 #define i_uid_high      osd2.linux2.l_i_uid_high
832 #define i_gid_high      osd2.linux2.l_i_gid_high
833 #define i_checksum_lo   osd2.linux2.l_i_checksum_lo
834 
835 #elif defined(__GNU__)
836 
837 #define i_translator    osd1.hurd1.h_i_translator
838 #define i_uid_high      osd2.hurd2.h_i_uid_high
839 #define i_gid_high      osd2.hurd2.h_i_gid_high
840 #define i_author        osd2.hurd2.h_i_author
841 
842 #elif defined(__masix__)
843 
844 #define i_reserved1     osd1.masix1.m_i_reserved1
845 #define i_file_acl_high osd2.masix2.m_i_file_acl_high
846 #define i_reserved2     osd2.masix2.m_i_reserved2
847 
848 #endif /* defined(__KERNEL__) || defined(__linux__) */
849 
850 #include "extents_status.h"
851 
852 /*
853  * fourth extended file system inode data in memory
854  */
855 struct ext4_inode_info {
856         __le32  i_data[15];     /* unconverted */
857         __u32   i_dtime;
858         ext4_fsblk_t    i_file_acl;
859 
860         /*
861          * i_block_group is the number of the block group which contains
862          * this file's inode.  Constant across the lifetime of the inode,
863          * it is ued for making block allocation decisions - we try to
864          * place a file's data blocks near its inode block, and new inodes
865          * near to their parent directory's inode.
866          */
867         ext4_group_t    i_block_group;
868         ext4_lblk_t     i_dir_start_lookup;
869 #if (BITS_PER_LONG < 64)
870         unsigned long   i_state_flags;          /* Dynamic state flags */
871 #endif
872         unsigned long   i_flags;
873 
874         /*
875          * Extended attributes can be read independently of the main file
876          * data. Taking i_mutex even when reading would cause contention
877          * between readers of EAs and writers of regular file data, so
878          * instead we synchronize on xattr_sem when reading or changing
879          * EAs.
880          */
881         struct rw_semaphore xattr_sem;
882 
883         struct list_head i_orphan;      /* unlinked but open inodes */
884 
885         /*
886          * i_disksize keeps track of what the inode size is ON DISK, not
887          * in memory.  During truncate, i_size is set to the new size by
888          * the VFS prior to calling ext4_truncate(), but the filesystem won't
889          * set i_disksize to 0 until the truncate is actually under way.
890          *
891          * The intent is that i_disksize always represents the blocks which
892          * are used by this file.  This allows recovery to restart truncate
893          * on orphans if we crash during truncate.  We actually write i_disksize
894          * into the on-disk inode when writing inodes out, instead of i_size.
895          *
896          * The only time when i_disksize and i_size may be different is when
897          * a truncate is in progress.  The only things which change i_disksize
898          * are ext4_get_block (growth) and ext4_truncate (shrinkth).
899          */
900         loff_t  i_disksize;
901 
902         /*
903          * i_data_sem is for serialising ext4_truncate() against
904          * ext4_getblock().  In the 2.4 ext2 design, great chunks of inode's
905          * data tree are chopped off during truncate. We can't do that in
906          * ext4 because whenever we perform intermediate commits during
907          * truncate, the inode and all the metadata blocks *must* be in a
908          * consistent state which allows truncation of the orphans to restart
909          * during recovery.  Hence we must fix the get_block-vs-truncate race
910          * by other means, so we have i_data_sem.
911          */
912         struct rw_semaphore i_data_sem;
913         struct inode vfs_inode;
914         struct jbd2_inode *jinode;
915 
916         spinlock_t i_raw_lock;  /* protects updates to the raw inode */
917 
918         /*
919          * File creation time. Its function is same as that of
920          * struct timespec i_{a,c,m}time in the generic inode.
921          */
922         struct timespec i_crtime;
923 
924         /* mballoc */
925         struct list_head i_prealloc_list;
926         spinlock_t i_prealloc_lock;
927 
928         /* extents status tree */
929         struct ext4_es_tree i_es_tree;
930         rwlock_t i_es_lock;
931         struct list_head i_es_list;
932         unsigned int i_es_all_nr;       /* protected by i_es_lock */
933         unsigned int i_es_shk_nr;       /* protected by i_es_lock */
934         ext4_lblk_t i_es_shrink_lblk;   /* Offset where we start searching for
935                                            extents to shrink. Protected by
936                                            i_es_lock  */
937 
938         /* ialloc */
939         ext4_group_t    i_last_alloc_group;
940 
941         /* allocation reservation info for delalloc */
942         /* In case of bigalloc, these refer to clusters rather than blocks */
943         unsigned int i_reserved_data_blocks;
944         unsigned int i_reserved_meta_blocks;
945         unsigned int i_allocated_meta_blocks;
946         ext4_lblk_t i_da_metadata_calc_last_lblock;
947         int i_da_metadata_calc_len;
948 
949         /* on-disk additional length */
950         __u16 i_extra_isize;
951 
952         /* Indicate the inline data space. */
953         u16 i_inline_off;
954         u16 i_inline_size;
955 
956 #ifdef CONFIG_QUOTA
957         /* quota space reservation, managed internally by quota code */
958         qsize_t i_reserved_quota;
959 #endif
960 
961         /* Lock protecting lists below */
962         spinlock_t i_completed_io_lock;
963         /*
964          * Completed IOs that need unwritten extents handling and have
965          * transaction reserved
966          */
967         struct list_head i_rsv_conversion_list;
968         /*
969          * Completed IOs that need unwritten extents handling and don't have
970          * transaction reserved
971          */
972         atomic_t i_ioend_count; /* Number of outstanding io_end structs */
973         atomic_t i_unwritten; /* Nr. of inflight conversions pending */
974         struct work_struct i_rsv_conversion_work;
975 
976         spinlock_t i_block_reservation_lock;
977 
978         /*
979          * Transactions that contain inode's metadata needed to complete
980          * fsync and fdatasync, respectively.
981          */
982         tid_t i_sync_tid;
983         tid_t i_datasync_tid;
984 
985 #ifdef CONFIG_QUOTA
986         struct dquot *i_dquot[MAXQUOTAS];
987 #endif
988 
989         /* Precomputed uuid+inum+igen checksum for seeding inode checksums */
990         __u32 i_csum_seed;
991 
992 #ifdef CONFIG_EXT4_FS_ENCRYPTION
993         /* Encryption params */
994         struct ext4_crypt_info *i_crypt_info;
995 #endif
996 };
997 
998 /*
999  * File system states
1000  */
1001 #define EXT4_VALID_FS                   0x0001  /* Unmounted cleanly */
1002 #define EXT4_ERROR_FS                   0x0002  /* Errors detected */
1003 #define EXT4_ORPHAN_FS                  0x0004  /* Orphans being recovered */
1004 
1005 /*
1006  * Misc. filesystem flags
1007  */
1008 #define EXT2_FLAGS_SIGNED_HASH          0x0001  /* Signed dirhash in use */
1009 #define EXT2_FLAGS_UNSIGNED_HASH        0x0002  /* Unsigned dirhash in use */
1010 #define EXT2_FLAGS_TEST_FILESYS         0x0004  /* to test development code */
1011 
1012 /*
1013  * Mount flags set via mount options or defaults
1014  */
1015 #define EXT4_MOUNT_GRPID                0x00004 /* Create files with directory's group */
1016 #define EXT4_MOUNT_DEBUG                0x00008 /* Some debugging messages */
1017 #define EXT4_MOUNT_ERRORS_CONT          0x00010 /* Continue on errors */
1018 #define EXT4_MOUNT_ERRORS_RO            0x00020 /* Remount fs ro on errors */
1019 #define EXT4_MOUNT_ERRORS_PANIC         0x00040 /* Panic on errors */
1020 #define EXT4_MOUNT_ERRORS_MASK          0x00070
1021 #define EXT4_MOUNT_MINIX_DF             0x00080 /* Mimics the Minix statfs */
1022 #define EXT4_MOUNT_NOLOAD               0x00100 /* Don't use existing journal*/
1023 #ifdef CONFIG_FS_DAX
1024 #define EXT4_MOUNT_DAX                  0x00200 /* Direct Access */
1025 #else
1026 #define EXT4_MOUNT_DAX                  0
1027 #endif
1028 #define EXT4_MOUNT_DATA_FLAGS           0x00C00 /* Mode for data writes: */
1029 #define EXT4_MOUNT_JOURNAL_DATA         0x00400 /* Write data to journal */
1030 #define EXT4_MOUNT_ORDERED_DATA         0x00800 /* Flush data before commit */
1031 #define EXT4_MOUNT_WRITEBACK_DATA       0x00C00 /* No data ordering */
1032 #define EXT4_MOUNT_UPDATE_JOURNAL       0x01000 /* Update the journal format */
1033 #define EXT4_MOUNT_NO_UID32             0x02000  /* Disable 32-bit UIDs */
1034 #define EXT4_MOUNT_XATTR_USER           0x04000 /* Extended user attributes */
1035 #define EXT4_MOUNT_POSIX_ACL            0x08000 /* POSIX Access Control Lists */
1036 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC     0x10000 /* No auto delalloc mapping */
1037 #define EXT4_MOUNT_BARRIER              0x20000 /* Use block barriers */
1038 #define EXT4_MOUNT_QUOTA                0x80000 /* Some quota option set */
1039 #define EXT4_MOUNT_USRQUOTA             0x100000 /* "old" user quota */
1040 #define EXT4_MOUNT_GRPQUOTA             0x200000 /* "old" group quota */
1041 #define EXT4_MOUNT_DIOREAD_NOLOCK       0x400000 /* Enable support for dio read nolocking */
1042 #define EXT4_MOUNT_JOURNAL_CHECKSUM     0x800000 /* Journal checksums */
1043 #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */
1044 #define EXT4_MOUNT_DELALLOC             0x8000000 /* Delalloc support */
1045 #define EXT4_MOUNT_DATA_ERR_ABORT       0x10000000 /* Abort on file data write */
1046 #define EXT4_MOUNT_BLOCK_VALIDITY       0x20000000 /* Block validity checking */
1047 #define EXT4_MOUNT_DISCARD              0x40000000 /* Issue DISCARD requests */
1048 #define EXT4_MOUNT_INIT_INODE_TABLE     0x80000000 /* Initialize uninitialized itables */
1049 
1050 /*
1051  * Mount flags set either automatically (could not be set by mount option)
1052  * based on per file system feature or property or in special cases such as
1053  * distinguishing between explicit mount option definition and default.
1054  */
1055 #define EXT4_MOUNT2_EXPLICIT_DELALLOC   0x00000001 /* User explicitly
1056                                                       specified delalloc */
1057 #define EXT4_MOUNT2_STD_GROUP_SIZE      0x00000002 /* We have standard group
1058                                                       size of blocksize * 8
1059                                                       blocks */
1060 #define EXT4_MOUNT2_HURD_COMPAT         0x00000004 /* Support HURD-castrated
1061                                                       file systems */
1062 
1063 #define EXT4_MOUNT2_EXPLICIT_JOURNAL_CHECKSUM   0x00000008 /* User explicitly
1064                                                 specified journal checksum */
1065 
1066 #define clear_opt(sb, opt)              EXT4_SB(sb)->s_mount_opt &= \
1067                                                 ~EXT4_MOUNT_##opt
1068 #define set_opt(sb, opt)                EXT4_SB(sb)->s_mount_opt |= \
1069                                                 EXT4_MOUNT_##opt
1070 #define test_opt(sb, opt)               (EXT4_SB(sb)->s_mount_opt & \
1071                                          EXT4_MOUNT_##opt)
1072 
1073 #define clear_opt2(sb, opt)             EXT4_SB(sb)->s_mount_opt2 &= \
1074                                                 ~EXT4_MOUNT2_##opt
1075 #define set_opt2(sb, opt)               EXT4_SB(sb)->s_mount_opt2 |= \
1076                                                 EXT4_MOUNT2_##opt
1077 #define test_opt2(sb, opt)              (EXT4_SB(sb)->s_mount_opt2 & \
1078                                          EXT4_MOUNT2_##opt)
1079 
1080 #define ext4_test_and_set_bit           __test_and_set_bit_le
1081 #define ext4_set_bit                    __set_bit_le
1082 #define ext4_set_bit_atomic             ext2_set_bit_atomic
1083 #define ext4_test_and_clear_bit         __test_and_clear_bit_le
1084 #define ext4_clear_bit                  __clear_bit_le
1085 #define ext4_clear_bit_atomic           ext2_clear_bit_atomic
1086 #define ext4_test_bit                   test_bit_le
1087 #define ext4_find_next_zero_bit         find_next_zero_bit_le
1088 #define ext4_find_next_bit              find_next_bit_le
1089 
1090 extern void ext4_set_bits(void *bm, int cur, int len);
1091 
1092 /*
1093  * Maximal mount counts between two filesystem checks
1094  */
1095 #define EXT4_DFL_MAX_MNT_COUNT          20      /* Allow 20 mounts */
1096 #define EXT4_DFL_CHECKINTERVAL          0       /* Don't use interval check */
1097 
1098 /*
1099  * Behaviour when detecting errors
1100  */
1101 #define EXT4_ERRORS_CONTINUE            1       /* Continue execution */
1102 #define EXT4_ERRORS_RO                  2       /* Remount fs read-only */
1103 #define EXT4_ERRORS_PANIC               3       /* Panic */
1104 #define EXT4_ERRORS_DEFAULT             EXT4_ERRORS_CONTINUE
1105 
1106 /* Metadata checksum algorithm codes */
1107 #define EXT4_CRC32C_CHKSUM              1
1108 
1109 /*
1110  * Structure of the super block
1111  */
1112 struct ext4_super_block {
1113 /*00*/  __le32  s_inodes_count;         /* Inodes count */
1114         __le32  s_blocks_count_lo;      /* Blocks count */
1115         __le32  s_r_blocks_count_lo;    /* Reserved blocks count */
1116         __le32  s_free_blocks_count_lo; /* Free blocks count */
1117 /*10*/  __le32  s_free_inodes_count;    /* Free inodes count */
1118         __le32  s_first_data_block;     /* First Data Block */
1119         __le32  s_log_block_size;       /* Block size */
1120         __le32  s_log_cluster_size;     /* Allocation cluster size */
1121 /*20*/  __le32  s_blocks_per_group;     /* # Blocks per group */
1122         __le32  s_clusters_per_group;   /* # Clusters per group */
1123         __le32  s_inodes_per_group;     /* # Inodes per group */
1124         __le32  s_mtime;                /* Mount time */
1125 /*30*/  __le32  s_wtime;                /* Write time */
1126         __le16  s_mnt_count;            /* Mount count */
1127         __le16  s_max_mnt_count;        /* Maximal mount count */
1128         __le16  s_magic;                /* Magic signature */
1129         __le16  s_state;                /* File system state */
1130         __le16  s_errors;               /* Behaviour when detecting errors */
1131         __le16  s_minor_rev_level;      /* minor revision level */
1132 /*40*/  __le32  s_lastcheck;            /* time of last check */
1133         __le32  s_checkinterval;        /* max. time between checks */
1134         __le32  s_creator_os;           /* OS */
1135         __le32  s_rev_level;            /* Revision level */
1136 /*50*/  __le16  s_def_resuid;           /* Default uid for reserved blocks */
1137         __le16  s_def_resgid;           /* Default gid for reserved blocks */
1138         /*
1139          * These fields are for EXT4_DYNAMIC_REV superblocks only.
1140          *
1141          * Note: the difference between the compatible feature set and
1142          * the incompatible feature set is that if there is a bit set
1143          * in the incompatible feature set that the kernel doesn't
1144          * know about, it should refuse to mount the filesystem.
1145          *
1146          * e2fsck's requirements are more strict; if it doesn't know
1147          * about a feature in either the compatible or incompatible
1148          * feature set, it must abort and not try to meddle with
1149          * things it doesn't understand...
1150          */
1151         __le32  s_first_ino;            /* First non-reserved inode */
1152         __le16  s_inode_size;           /* size of inode structure */
1153         __le16  s_block_group_nr;       /* block group # of this superblock */
1154         __le32  s_feature_compat;       /* compatible feature set */
1155 /*60*/  __le32  s_feature_incompat;     /* incompatible feature set */
1156         __le32  s_feature_ro_compat;    /* readonly-compatible feature set */
1157 /*68*/  __u8    s_uuid[16];             /* 128-bit uuid for volume */
1158 /*78*/  char    s_volume_name[16];      /* volume name */
1159 /*88*/  char    s_last_mounted[64];     /* directory where last mounted */
1160 /*C8*/  __le32  s_algorithm_usage_bitmap; /* For compression */
1161         /*
1162          * Performance hints.  Directory preallocation should only
1163          * happen if the EXT4_FEATURE_COMPAT_DIR_PREALLOC flag is on.
1164          */
1165         __u8    s_prealloc_blocks;      /* Nr of blocks to try to preallocate*/
1166         __u8    s_prealloc_dir_blocks;  /* Nr to preallocate for dirs */
1167         __le16  s_reserved_gdt_blocks;  /* Per group desc for online growth */
1168         /*
1169          * Journaling support valid if EXT4_FEATURE_COMPAT_HAS_JOURNAL set.
1170          */
1171 /*D0*/  __u8    s_journal_uuid[16];     /* uuid of journal superblock */
1172 /*E0*/  __le32  s_journal_inum;         /* inode number of journal file */
1173         __le32  s_journal_dev;          /* device number of journal file */
1174         __le32  s_last_orphan;          /* start of list of inodes to delete */
1175         __le32  s_hash_seed[4];         /* HTREE hash seed */
1176         __u8    s_def_hash_version;     /* Default hash version to use */
1177         __u8    s_jnl_backup_type;
1178         __le16  s_desc_size;            /* size of group descriptor */
1179 /*100*/ __le32  s_default_mount_opts;
1180         __le32  s_first_meta_bg;        /* First metablock block group */
1181         __le32  s_mkfs_time;            /* When the filesystem was created */
1182         __le32  s_jnl_blocks[17];       /* Backup of the journal inode */
1183         /* 64bit support valid if EXT4_FEATURE_COMPAT_64BIT */
1184 /*150*/ __le32  s_blocks_count_hi;      /* Blocks count */
1185         __le32  s_r_blocks_count_hi;    /* Reserved blocks count */
1186         __le32  s_free_blocks_count_hi; /* Free blocks count */
1187         __le16  s_min_extra_isize;      /* All inodes have at least # bytes */
1188         __le16  s_want_extra_isize;     /* New inodes should reserve # bytes */
1189         __le32  s_flags;                /* Miscellaneous flags */
1190         __le16  s_raid_stride;          /* RAID stride */
1191         __le16  s_mmp_update_interval;  /* # seconds to wait in MMP checking */
1192         __le64  s_mmp_block;            /* Block for multi-mount protection */
1193         __le32  s_raid_stripe_width;    /* blocks on all data disks (N*stride)*/
1194         __u8    s_log_groups_per_flex;  /* FLEX_BG group size */
1195         __u8    s_checksum_type;        /* metadata checksum algorithm used */
1196         __u8    s_encryption_level;     /* versioning level for encryption */
1197         __u8    s_reserved_pad;         /* Padding to next 32bits */
1198         __le64  s_kbytes_written;       /* nr of lifetime kilobytes written */
1199         __le32  s_snapshot_inum;        /* Inode number of active snapshot */
1200         __le32  s_snapshot_id;          /* sequential ID of active snapshot */
1201         __le64  s_snapshot_r_blocks_count; /* reserved blocks for active
1202                                               snapshot's future use */
1203         __le32  s_snapshot_list;        /* inode number of the head of the
1204                                            on-disk snapshot list */
1205 #define EXT4_S_ERR_START offsetof(struct ext4_super_block, s_error_count)
1206         __le32  s_error_count;          /* number of fs errors */
1207         __le32  s_first_error_time;     /* first time an error happened */
1208         __le32  s_first_error_ino;      /* inode involved in first error */
1209         __le64  s_first_error_block;    /* block involved of first error */
1210         __u8    s_first_error_func[32]; /* function where the error happened */
1211         __le32  s_first_error_line;     /* line number where error happened */
1212         __le32  s_last_error_time;      /* most recent time of an error */
1213         __le32  s_last_error_ino;       /* inode involved in last error */
1214         __le32  s_last_error_line;      /* line number where error happened */
1215         __le64  s_last_error_block;     /* block involved of last error */
1216         __u8    s_last_error_func[32];  /* function where the error happened */
1217 #define EXT4_S_ERR_END offsetof(struct ext4_super_block, s_mount_opts)
1218         __u8    s_mount_opts[64];
1219         __le32  s_usr_quota_inum;       /* inode for tracking user quota */
1220         __le32  s_grp_quota_inum;       /* inode for tracking group quota */
1221         __le32  s_overhead_clusters;    /* overhead blocks/clusters in fs */
1222         __le32  s_backup_bgs[2];        /* groups with sparse_super2 SBs */
1223         __u8    s_encrypt_algos[4];     /* Encryption algorithms in use  */
1224         __u8    s_encrypt_pw_salt[16];  /* Salt used for string2key algorithm */
1225         __le32  s_lpf_ino;              /* Location of the lost+found inode */
1226         __le32  s_prj_quota_inum;       /* inode for tracking project quota */
1227         __le32  s_checksum_seed;        /* crc32c(uuid) if csum_seed set */
1228         __le32  s_reserved[98];         /* Padding to the end of the block */
1229         __le32  s_checksum;             /* crc32c(superblock) */
1230 };
1231 
1232 #define EXT4_S_ERR_LEN (EXT4_S_ERR_END - EXT4_S_ERR_START)
1233 
1234 #ifdef __KERNEL__
1235 
1236 /*
1237  * run-time mount flags
1238  */
1239 #define EXT4_MF_MNTDIR_SAMPLED          0x0001
1240 #define EXT4_MF_FS_ABORTED              0x0002  /* Fatal error detected */
1241 #define EXT4_MF_TEST_DUMMY_ENCRYPTION   0x0004
1242 
1243 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1244 #define DUMMY_ENCRYPTION_ENABLED(sbi) (unlikely((sbi)->s_mount_flags & \
1245                                                 EXT4_MF_TEST_DUMMY_ENCRYPTION))
1246 #else
1247 #define DUMMY_ENCRYPTION_ENABLED(sbi) (0)
1248 #endif
1249 
1250 /* Number of quota types we support */
1251 #define EXT4_MAXQUOTAS 2
1252 
1253 /*
1254  * fourth extended-fs super-block data in memory
1255  */
1256 struct ext4_sb_info {
1257         unsigned long s_desc_size;      /* Size of a group descriptor in bytes */
1258         unsigned long s_inodes_per_block;/* Number of inodes per block */
1259         unsigned long s_blocks_per_group;/* Number of blocks in a group */
1260         unsigned long s_clusters_per_group; /* Number of clusters in a group */
1261         unsigned long s_inodes_per_group;/* Number of inodes in a group */
1262         unsigned long s_itb_per_group;  /* Number of inode table blocks per group */
1263         unsigned long s_gdb_count;      /* Number of group descriptor blocks */
1264         unsigned long s_desc_per_block; /* Number of group descriptors per block */
1265         ext4_group_t s_groups_count;    /* Number of groups in the fs */
1266         ext4_group_t s_blockfile_groups;/* Groups acceptable for non-extent files */
1267         unsigned long s_overhead;  /* # of fs overhead clusters */
1268         unsigned int s_cluster_ratio;   /* Number of blocks per cluster */
1269         unsigned int s_cluster_bits;    /* log2 of s_cluster_ratio */
1270         loff_t s_bitmap_maxbytes;       /* max bytes for bitmap files */
1271         struct buffer_head * s_sbh;     /* Buffer containing the super block */
1272         struct ext4_super_block *s_es;  /* Pointer to the super block in the buffer */
1273         struct buffer_head **s_group_desc;
1274         unsigned int s_mount_opt;
1275         unsigned int s_mount_opt2;
1276         unsigned int s_mount_flags;
1277         unsigned int s_def_mount_opt;
1278         ext4_fsblk_t s_sb_block;
1279         atomic64_t s_resv_clusters;
1280         kuid_t s_resuid;
1281         kgid_t s_resgid;
1282         unsigned short s_mount_state;
1283         unsigned short s_pad;
1284         int s_addr_per_block_bits;
1285         int s_desc_per_block_bits;
1286         int s_inode_size;
1287         int s_first_ino;
1288         unsigned int s_inode_readahead_blks;
1289         unsigned int s_inode_goal;
1290         spinlock_t s_next_gen_lock;
1291         u32 s_next_generation;
1292         u32 s_hash_seed[4];
1293         int s_def_hash_version;
1294         int s_hash_unsigned;    /* 3 if hash should be signed, 0 if not */
1295         struct percpu_counter s_freeclusters_counter;
1296         struct percpu_counter s_freeinodes_counter;
1297         struct percpu_counter s_dirs_counter;
1298         struct percpu_counter s_dirtyclusters_counter;
1299         struct blockgroup_lock *s_blockgroup_lock;
1300         struct proc_dir_entry *s_proc;
1301         struct kobject s_kobj;
1302         struct completion s_kobj_unregister;
1303         struct super_block *s_sb;
1304 
1305         /* Journaling */
1306         struct journal_s *s_journal;
1307         struct list_head s_orphan;
1308         struct mutex s_orphan_lock;
1309         unsigned long s_resize_flags;           /* Flags indicating if there
1310                                                    is a resizer */
1311         unsigned long s_commit_interval;
1312         u32 s_max_batch_time;
1313         u32 s_min_batch_time;
1314         struct block_device *journal_bdev;
1315 #ifdef CONFIG_QUOTA
1316         char *s_qf_names[EXT4_MAXQUOTAS];       /* Names of quota files with journalled quota */
1317         int s_jquota_fmt;                       /* Format of quota to use */
1318 #endif
1319         unsigned int s_want_extra_isize; /* New inodes should reserve # bytes */
1320         struct rb_root system_blks;
1321 
1322 #ifdef EXTENTS_STATS
1323         /* ext4 extents stats */
1324         unsigned long s_ext_min;
1325         unsigned long s_ext_max;
1326         unsigned long s_depth_max;
1327         spinlock_t s_ext_stats_lock;
1328         unsigned long s_ext_blocks;
1329         unsigned long s_ext_extents;
1330 #endif
1331 
1332         /* for buddy allocator */
1333         struct ext4_group_info ***s_group_info;
1334         struct inode *s_buddy_cache;
1335         spinlock_t s_md_lock;
1336         unsigned short *s_mb_offsets;
1337         unsigned int *s_mb_maxs;
1338         unsigned int s_group_info_size;
1339 
1340         /* tunables */
1341         unsigned long s_stripe;
1342         unsigned int s_mb_stream_request;
1343         unsigned int s_mb_max_to_scan;
1344         unsigned int s_mb_min_to_scan;
1345         unsigned int s_mb_stats;
1346         unsigned int s_mb_order2_reqs;
1347         unsigned int s_mb_group_prealloc;
1348         unsigned int s_max_dir_size_kb;
1349         /* where last allocation was done - for stream allocation */
1350         unsigned long s_mb_last_group;
1351         unsigned long s_mb_last_start;
1352 
1353         /* stats for buddy allocator */
1354         atomic_t s_bal_reqs;    /* number of reqs with len > 1 */
1355         atomic_t s_bal_success; /* we found long enough chunks */
1356         atomic_t s_bal_allocated;       /* in blocks */
1357         atomic_t s_bal_ex_scanned;      /* total extents scanned */
1358         atomic_t s_bal_goals;   /* goal hits */
1359         atomic_t s_bal_breaks;  /* too long searches */
1360         atomic_t s_bal_2orders; /* 2^order hits */
1361         spinlock_t s_bal_lock;
1362         unsigned long s_mb_buddies_generated;
1363         unsigned long long s_mb_generation_time;
1364         atomic_t s_mb_lost_chunks;
1365         atomic_t s_mb_preallocated;
1366         atomic_t s_mb_discarded;
1367         atomic_t s_lock_busy;
1368 
1369         /* locality groups */
1370         struct ext4_locality_group __percpu *s_locality_groups;
1371 
1372         /* for write statistics */
1373         unsigned long s_sectors_written_start;
1374         u64 s_kbytes_written;
1375 
1376         /* the size of zero-out chunk */
1377         unsigned int s_extent_max_zeroout_kb;
1378 
1379         unsigned int s_log_groups_per_flex;
1380         struct flex_groups *s_flex_groups;
1381         ext4_group_t s_flex_groups_allocated;
1382 
1383         /* workqueue for reserved extent conversions (buffered io) */
1384         struct workqueue_struct *rsv_conversion_wq;
1385 
1386         /* timer for periodic error stats printing */
1387         struct timer_list s_err_report;
1388 
1389         /* Lazy inode table initialization info */
1390         struct ext4_li_request *s_li_request;
1391         /* Wait multiplier for lazy initialization thread */
1392         unsigned int s_li_wait_mult;
1393 
1394         /* Kernel thread for multiple mount protection */
1395         struct task_struct *s_mmp_tsk;
1396 
1397         /* record the last minlen when FITRIM is called. */
1398         atomic_t s_last_trim_minblks;
1399 
1400         /* Reference to checksum algorithm driver via cryptoapi */
1401         struct crypto_shash *s_chksum_driver;
1402 
1403         /* Precomputed FS UUID checksum for seeding other checksums */
1404         __u32 s_csum_seed;
1405 
1406         /* Reclaim extents from extent status tree */
1407         struct shrinker s_es_shrinker;
1408         struct list_head s_es_list;     /* List of inodes with reclaimable extents */
1409         long s_es_nr_inode;
1410         struct ext4_es_stats s_es_stats;
1411         struct mb_cache *s_mb_cache;
1412         spinlock_t s_es_lock ____cacheline_aligned_in_smp;
1413 
1414         /* Ratelimit ext4 messages. */
1415         struct ratelimit_state s_err_ratelimit_state;
1416         struct ratelimit_state s_warning_ratelimit_state;
1417         struct ratelimit_state s_msg_ratelimit_state;
1418 };
1419 
1420 static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb)
1421 {
1422         return sb->s_fs_info;
1423 }
1424 static inline struct ext4_inode_info *EXT4_I(struct inode *inode)
1425 {
1426         return container_of(inode, struct ext4_inode_info, vfs_inode);
1427 }
1428 
1429 static inline struct timespec ext4_current_time(struct inode *inode)
1430 {
1431         return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
1432                 current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
1433 }
1434 
1435 static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
1436 {
1437         return ino == EXT4_ROOT_INO ||
1438                 ino == EXT4_USR_QUOTA_INO ||
1439                 ino == EXT4_GRP_QUOTA_INO ||
1440                 ino == EXT4_BOOT_LOADER_INO ||
1441                 ino == EXT4_JOURNAL_INO ||
1442                 ino == EXT4_RESIZE_INO ||
1443                 (ino >= EXT4_FIRST_INO(sb) &&
1444                  ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
1445 }
1446 
1447 static inline void ext4_set_io_unwritten_flag(struct inode *inode,
1448                                               struct ext4_io_end *io_end)
1449 {
1450         if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
1451                 io_end->flag |= EXT4_IO_END_UNWRITTEN;
1452                 atomic_inc(&EXT4_I(inode)->i_unwritten);
1453         }
1454 }
1455 
1456 static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
1457 {
1458         return inode->i_private;
1459 }
1460 
1461 static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
1462 {
1463         inode->i_private = io;
1464 }
1465 
1466 /*
1467  * Inode dynamic state flags
1468  */
1469 enum {
1470         EXT4_STATE_JDATA,               /* journaled data exists */
1471         EXT4_STATE_NEW,                 /* inode is newly created */
1472         EXT4_STATE_XATTR,               /* has in-inode xattrs */
1473         EXT4_STATE_NO_EXPAND,           /* No space for expansion */
1474         EXT4_STATE_DA_ALLOC_CLOSE,      /* Alloc DA blks on close */
1475         EXT4_STATE_EXT_MIGRATE,         /* Inode is migrating */
1476         EXT4_STATE_DIO_UNWRITTEN,       /* need convert on dio done*/
1477         EXT4_STATE_NEWENTRY,            /* File just added to dir */
1478         EXT4_STATE_DIOREAD_LOCK,        /* Disable support for dio read
1479                                            nolocking */
1480         EXT4_STATE_MAY_INLINE_DATA,     /* may have in-inode data */
1481         EXT4_STATE_ORDERED_MODE,        /* data=ordered mode */
1482         EXT4_STATE_EXT_PRECACHED,       /* extents have been precached */
1483 };
1484 
1485 #define EXT4_INODE_BIT_FNS(name, field, offset)                         \
1486 static inline int ext4_test_inode_##name(struct inode *inode, int bit)  \
1487 {                                                                       \
1488         return test_bit(bit + (offset), &EXT4_I(inode)->i_##field);     \
1489 }                                                                       \
1490 static inline void ext4_set_inode_##name(struct inode *inode, int bit)  \
1491 {                                                                       \
1492         set_bit(bit + (offset), &EXT4_I(inode)->i_##field);             \
1493 }                                                                       \
1494 static inline void ext4_clear_inode_##name(struct inode *inode, int bit) \
1495 {                                                                       \
1496         clear_bit(bit + (offset), &EXT4_I(inode)->i_##field);           \
1497 }
1498 
1499 /* Add these declarations here only so that these functions can be
1500  * found by name.  Otherwise, they are very hard to locate. */
1501 static inline int ext4_test_inode_flag(struct inode *inode, int bit);
1502 static inline void ext4_set_inode_flag(struct inode *inode, int bit);
1503 static inline void ext4_clear_inode_flag(struct inode *inode, int bit);
1504 EXT4_INODE_BIT_FNS(flag, flags, 0)
1505 
1506 /* Add these declarations here only so that these functions can be
1507  * found by name.  Otherwise, they are very hard to locate. */
1508 static inline int ext4_test_inode_state(struct inode *inode, int bit);
1509 static inline void ext4_set_inode_state(struct inode *inode, int bit);
1510 static inline void ext4_clear_inode_state(struct inode *inode, int bit);
1511 #if (BITS_PER_LONG < 64)
1512 EXT4_INODE_BIT_FNS(state, state_flags, 0)
1513 
1514 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1515 {
1516         (ei)->i_state_flags = 0;
1517 }
1518 #else
1519 EXT4_INODE_BIT_FNS(state, flags, 32)
1520 
1521 static inline void ext4_clear_state_flags(struct ext4_inode_info *ei)
1522 {
1523         /* We depend on the fact that callers will set i_flags */
1524 }
1525 #endif
1526 #else
1527 /* Assume that user mode programs are passing in an ext4fs superblock, not
1528  * a kernel struct super_block.  This will allow us to call the feature-test
1529  * macros from user land. */
1530 #define EXT4_SB(sb)     (sb)
1531 #endif
1532 
1533 /*
1534  * Returns true if the inode is inode is encrypted
1535  */
1536 static inline int ext4_encrypted_inode(struct inode *inode)
1537 {
1538 #ifdef CONFIG_EXT4_FS_ENCRYPTION
1539         return ext4_test_inode_flag(inode, EXT4_INODE_ENCRYPT);
1540 #else
1541         return 0;
1542 #endif
1543 }
1544 
1545 #define NEXT_ORPHAN(inode) EXT4_I(inode)->i_dtime
1546 
1547 /*
1548  * Codes for operating systems
1549  */
1550 #define EXT4_OS_LINUX           0
1551 #define EXT4_OS_HURD            1
1552 #define EXT4_OS_MASIX           2
1553 #define EXT4_OS_FREEBSD         3
1554 #define EXT4_OS_LITES           4
1555 
1556 /*
1557  * Revision levels
1558  */
1559 #define EXT4_GOOD_OLD_REV       0       /* The good old (original) format */
1560 #define EXT4_DYNAMIC_REV        1       /* V2 format w/ dynamic inode sizes */
1561 
1562 #define EXT4_CURRENT_REV        EXT4_GOOD_OLD_REV
1563 #define EXT4_MAX_SUPP_REV       EXT4_DYNAMIC_REV
1564 
1565 #define EXT4_GOOD_OLD_INODE_SIZE 128
1566 
1567 /*
1568  * Feature set definitions
1569  */
1570 
1571 /* Use the ext4_{has,set,clear}_feature_* helpers; these will be removed */
1572 #define EXT4_HAS_COMPAT_FEATURE(sb,mask)                        \
1573         ((EXT4_SB(sb)->s_es->s_feature_compat & cpu_to_le32(mask)) != 0)
1574 #define EXT4_HAS_RO_COMPAT_FEATURE(sb,mask)                     \
1575         ((EXT4_SB(sb)->s_es->s_feature_ro_compat & cpu_to_le32(mask)) != 0)
1576 #define EXT4_HAS_INCOMPAT_FEATURE(sb,mask)                      \
1577         ((EXT4_SB(sb)->s_es->s_feature_incompat & cpu_to_le32(mask)) != 0)
1578 #define EXT4_SET_COMPAT_FEATURE(sb,mask)                        \
1579         EXT4_SB(sb)->s_es->s_feature_compat |= cpu_to_le32(mask)
1580 #define EXT4_SET_RO_COMPAT_FEATURE(sb,mask)                     \
1581         EXT4_SB(sb)->s_es->s_feature_ro_compat |= cpu_to_le32(mask)
1582 #define EXT4_SET_INCOMPAT_FEATURE(sb,mask)                      \
1583         EXT4_SB(sb)->s_es->s_feature_incompat |= cpu_to_le32(mask)
1584 #define EXT4_CLEAR_COMPAT_FEATURE(sb,mask)                      \
1585         EXT4_SB(sb)->s_es->s_feature_compat &= ~cpu_to_le32(mask)
1586 #define EXT4_CLEAR_RO_COMPAT_FEATURE(sb,mask)                   \
1587         EXT4_SB(sb)->s_es->s_feature_ro_compat &= ~cpu_to_le32(mask)
1588 #define EXT4_CLEAR_INCOMPAT_FEATURE(sb,mask)                    \
1589         EXT4_SB(sb)->s_es->s_feature_incompat &= ~cpu_to_le32(mask)
1590 
1591 #define EXT4_FEATURE_COMPAT_DIR_PREALLOC        0x0001
1592 #define EXT4_FEATURE_COMPAT_IMAGIC_INODES       0x0002
1593 #define EXT4_FEATURE_COMPAT_HAS_JOURNAL         0x0004
1594 #define EXT4_FEATURE_COMPAT_EXT_ATTR            0x0008
1595 #define EXT4_FEATURE_COMPAT_RESIZE_INODE        0x0010
1596 #define EXT4_FEATURE_COMPAT_DIR_INDEX           0x0020
1597 #define EXT4_FEATURE_COMPAT_SPARSE_SUPER2       0x0200
1598 
1599 #define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER     0x0001
1600 #define EXT4_FEATURE_RO_COMPAT_LARGE_FILE       0x0002
1601 #define EXT4_FEATURE_RO_COMPAT_BTREE_DIR        0x0004
1602 #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE        0x0008
1603 #define EXT4_FEATURE_RO_COMPAT_GDT_CSUM         0x0010
1604 #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK        0x0020
1605 #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE      0x0040
1606 #define EXT4_FEATURE_RO_COMPAT_QUOTA            0x0100
1607 #define EXT4_FEATURE_RO_COMPAT_BIGALLOC         0x0200
1608 /*
1609  * METADATA_CSUM also enables group descriptor checksums (GDT_CSUM).  When
1610  * METADATA_CSUM is set, group descriptor checksums use the same algorithm as
1611  * all other data structures' checksums.  However, the METADATA_CSUM and
1612  * GDT_CSUM bits are mutually exclusive.
1613  */
1614 #define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM    0x0400
1615 #define EXT4_FEATURE_RO_COMPAT_READONLY         0x1000
1616 #define EXT4_FEATURE_RO_COMPAT_PROJECT          0x2000
1617 
1618 #define EXT4_FEATURE_INCOMPAT_COMPRESSION       0x0001
1619 #define EXT4_FEATURE_INCOMPAT_FILETYPE          0x0002
1620 #define EXT4_FEATURE_INCOMPAT_RECOVER           0x0004 /* Needs recovery */
1621 #define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV       0x0008 /* Journal device */
1622 #define EXT4_FEATURE_INCOMPAT_META_BG           0x0010
1623 #define EXT4_FEATURE_INCOMPAT_EXTENTS           0x0040 /* extents support */
1624 #define EXT4_FEATURE_INCOMPAT_64BIT             0x0080
1625 #define EXT4_FEATURE_INCOMPAT_MMP               0x0100
1626 #define EXT4_FEATURE_INCOMPAT_FLEX_BG           0x0200
1627 #define EXT4_FEATURE_INCOMPAT_EA_INODE          0x0400 /* EA in inode */
1628 #define EXT4_FEATURE_INCOMPAT_DIRDATA           0x1000 /* data in dirent */
1629 #define EXT4_FEATURE_INCOMPAT_CSUM_SEED         0x2000
1630 #define EXT4_FEATURE_INCOMPAT_LARGEDIR          0x4000 /* >2GB or 3-lvl htree */
1631 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA       0x8000 /* data in inode */
1632 #define EXT4_FEATURE_INCOMPAT_ENCRYPT           0x10000
1633 
1634 #define EXT4_FEATURE_COMPAT_FUNCS(name, flagname) \
1635 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1636 { \
1637         return ((EXT4_SB(sb)->s_es->s_feature_compat & \
1638                 cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname)) != 0); \
1639 } \
1640 static inline void ext4_set_feature_##name(struct super_block *sb) \
1641 { \
1642         EXT4_SB(sb)->s_es->s_feature_compat |= \
1643                 cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \
1644 } \
1645 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1646 { \
1647         EXT4_SB(sb)->s_es->s_feature_compat &= \
1648                 ~cpu_to_le32(EXT4_FEATURE_COMPAT_##flagname); \
1649 }
1650 
1651 #define EXT4_FEATURE_RO_COMPAT_FUNCS(name, flagname) \
1652 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1653 { \
1654         return ((EXT4_SB(sb)->s_es->s_feature_ro_compat & \
1655                 cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname)) != 0); \
1656 } \
1657 static inline void ext4_set_feature_##name(struct super_block *sb) \
1658 { \
1659         EXT4_SB(sb)->s_es->s_feature_ro_compat |= \
1660                 cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \
1661 } \
1662 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1663 { \
1664         EXT4_SB(sb)->s_es->s_feature_ro_compat &= \
1665                 ~cpu_to_le32(EXT4_FEATURE_RO_COMPAT_##flagname); \
1666 }
1667 
1668 #define EXT4_FEATURE_INCOMPAT_FUNCS(name, flagname) \
1669 static inline bool ext4_has_feature_##name(struct super_block *sb) \
1670 { \
1671         return ((EXT4_SB(sb)->s_es->s_feature_incompat & \
1672                 cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname)) != 0); \
1673 } \
1674 static inline void ext4_set_feature_##name(struct super_block *sb) \
1675 { \
1676         EXT4_SB(sb)->s_es->s_feature_incompat |= \
1677                 cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \
1678 } \
1679 static inline void ext4_clear_feature_##name(struct super_block *sb) \
1680 { \
1681         EXT4_SB(sb)->s_es->s_feature_incompat &= \
1682                 ~cpu_to_le32(EXT4_FEATURE_INCOMPAT_##flagname); \
1683 }
1684 
1685 EXT4_FEATURE_COMPAT_FUNCS(dir_prealloc,         DIR_PREALLOC)
1686 EXT4_FEATURE_COMPAT_FUNCS(imagic_inodes,        IMAGIC_INODES)
1687 EXT4_FEATURE_COMPAT_FUNCS(journal,              HAS_JOURNAL)
1688 EXT4_FEATURE_COMPAT_FUNCS(xattr,                EXT_ATTR)
1689 EXT4_FEATURE_COMPAT_FUNCS(resize_inode,         RESIZE_INODE)
1690 EXT4_FEATURE_COMPAT_FUNCS(dir_index,            DIR_INDEX)
1691 EXT4_FEATURE_COMPAT_FUNCS(sparse_super2,        SPARSE_SUPER2)
1692 
1693 EXT4_FEATURE_RO_COMPAT_FUNCS(sparse_super,      SPARSE_SUPER)
1694 EXT4_FEATURE_RO_COMPAT_FUNCS(large_file,        LARGE_FILE)
1695 EXT4_FEATURE_RO_COMPAT_FUNCS(btree_dir,         BTREE_DIR)
1696 EXT4_FEATURE_RO_COMPAT_FUNCS(huge_file,         HUGE_FILE)
1697 EXT4_FEATURE_RO_COMPAT_FUNCS(gdt_csum,          GDT_CSUM)
1698 EXT4_FEATURE_RO_COMPAT_FUNCS(dir_nlink,         DIR_NLINK)
1699 EXT4_FEATURE_RO_COMPAT_FUNCS(extra_isize,       EXTRA_ISIZE)
1700 EXT4_FEATURE_RO_COMPAT_FUNCS(quota,             QUOTA)
1701 EXT4_FEATURE_RO_COMPAT_FUNCS(bigalloc,          BIGALLOC)
1702 EXT4_FEATURE_RO_COMPAT_FUNCS(metadata_csum,     METADATA_CSUM)
1703 EXT4_FEATURE_RO_COMPAT_FUNCS(readonly,          READONLY)
1704 EXT4_FEATURE_RO_COMPAT_FUNCS(project,           PROJECT)
1705 
1706 EXT4_FEATURE_INCOMPAT_FUNCS(compression,        COMPRESSION)
1707 EXT4_FEATURE_INCOMPAT_FUNCS(filetype,           FILETYPE)
1708 EXT4_FEATURE_INCOMPAT_FUNCS(journal_needs_recovery,     RECOVER)
1709 EXT4_FEATURE_INCOMPAT_FUNCS(journal_dev,        JOURNAL_DEV)
1710 EXT4_FEATURE_INCOMPAT_FUNCS(meta_bg,            META_BG)
1711 EXT4_FEATURE_INCOMPAT_FUNCS(extents,            EXTENTS)
1712 EXT4_FEATURE_INCOMPAT_FUNCS(64bit,              64BIT)
1713 EXT4_FEATURE_INCOMPAT_FUNCS(mmp,                MMP)
1714 EXT4_FEATURE_INCOMPAT_FUNCS(flex_bg,            FLEX_BG)
1715 EXT4_FEATURE_INCOMPAT_FUNCS(ea_inode,           EA_INODE)
1716 EXT4_FEATURE_INCOMPAT_FUNCS(dirdata,            DIRDATA)
1717 EXT4_FEATURE_INCOMPAT_FUNCS(csum_seed,          CSUM_SEED)
1718 EXT4_FEATURE_INCOMPAT_FUNCS(largedir,           LARGEDIR)
1719 EXT4_FEATURE_INCOMPAT_FUNCS(inline_data,        INLINE_DATA)
1720 EXT4_FEATURE_INCOMPAT_FUNCS(encrypt,            ENCRYPT)
1721 
1722 #define EXT2_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1723 #define EXT2_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1724                                          EXT4_FEATURE_INCOMPAT_META_BG)
1725 #define EXT2_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1726                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1727                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1728 
1729 #define EXT3_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1730 #define EXT3_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1731                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1732                                          EXT4_FEATURE_INCOMPAT_META_BG)
1733 #define EXT3_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1734                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1735                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR)
1736 
1737 #define EXT4_FEATURE_COMPAT_SUPP        EXT4_FEATURE_COMPAT_EXT_ATTR
1738 #define EXT4_FEATURE_INCOMPAT_SUPP      (EXT4_FEATURE_INCOMPAT_FILETYPE| \
1739                                          EXT4_FEATURE_INCOMPAT_RECOVER| \
1740                                          EXT4_FEATURE_INCOMPAT_META_BG| \
1741                                          EXT4_FEATURE_INCOMPAT_EXTENTS| \
1742                                          EXT4_FEATURE_INCOMPAT_64BIT| \
1743                                          EXT4_FEATURE_INCOMPAT_FLEX_BG| \
1744                                          EXT4_FEATURE_INCOMPAT_MMP | \
1745                                          EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
1746                                          EXT4_FEATURE_INCOMPAT_ENCRYPT | \
1747                                          EXT4_FEATURE_INCOMPAT_CSUM_SEED)
1748 #define EXT4_FEATURE_RO_COMPAT_SUPP     (EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
1749                                          EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
1750                                          EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
1751                                          EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
1752                                          EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
1753                                          EXT4_FEATURE_RO_COMPAT_BTREE_DIR |\
1754                                          EXT4_FEATURE_RO_COMPAT_HUGE_FILE |\
1755                                          EXT4_FEATURE_RO_COMPAT_BIGALLOC |\
1756                                          EXT4_FEATURE_RO_COMPAT_METADATA_CSUM|\
1757                                          EXT4_FEATURE_RO_COMPAT_QUOTA)
1758 
1759 #define EXTN_FEATURE_FUNCS(ver) \
1760 static inline bool ext4_has_unknown_ext##ver##_compat_features(struct super_block *sb) \
1761 { \
1762         return ((EXT4_SB(sb)->s_es->s_feature_compat & \
1763                 cpu_to_le32(~EXT##ver##_FEATURE_COMPAT_SUPP)) != 0); \
1764 } \
1765 static inline bool ext4_has_unknown_ext##ver##_ro_compat_features(struct super_block *sb) \
1766 { \
1767         return ((EXT4_SB(sb)->s_es->s_feature_ro_compat & \
1768                 cpu_to_le32(~EXT##ver##_FEATURE_RO_COMPAT_SUPP)) != 0); \
1769 } \
1770 static inline bool ext4_has_unknown_ext##ver##_incompat_features(struct super_block *sb) \
1771 { \
1772         return ((EXT4_SB(sb)->s_es->s_feature_incompat & \
1773                 cpu_to_le32(~EXT##ver##_FEATURE_INCOMPAT_SUPP)) != 0); \
1774 }
1775 
1776 EXTN_FEATURE_FUNCS(2)
1777 EXTN_FEATURE_FUNCS(3)
1778 EXTN_FEATURE_FUNCS(4)
1779 
1780 static inline bool ext4_has_compat_features(struct super_block *sb)
1781 {
1782         return (EXT4_SB(sb)->s_es->s_feature_compat != 0);
1783 }
1784 static inline bool ext4_has_ro_compat_features(struct super_block *sb)
1785 {
1786         return (EXT4_SB(sb)->s_es->s_feature_ro_compat != 0);
1787 }
1788 static inline bool ext4_has_incompat_features(struct super_block *sb)
1789 {
1790         return (EXT4_SB(sb)->s_es->s_feature_incompat != 0);
1791 }
1792 
1793 /*
1794  * Default values for user and/or group using reserved blocks
1795  */
1796 #define EXT4_DEF_RESUID         0
1797 #define EXT4_DEF_RESGID         0
1798 
1799 #define EXT4_DEF_INODE_READAHEAD_BLKS   32
1800 
1801 /*
1802  * Default mount options
1803  */
1804 #define EXT4_DEFM_DEBUG         0x0001
1805 #define EXT4_DEFM_BSDGROUPS     0x0002
1806 #define EXT4_DEFM_XATTR_USER    0x0004
1807 #define EXT4_DEFM_ACL           0x0008
1808 #define EXT4_DEFM_UID16         0x0010
1809 #define EXT4_DEFM_JMODE         0x0060
1810 #define EXT4_DEFM_JMODE_DATA    0x0020
1811 #define EXT4_DEFM_JMODE_ORDERED 0x0040
1812 #define EXT4_DEFM_JMODE_WBACK   0x0060
1813 #define EXT4_DEFM_NOBARRIER     0x0100
1814 #define EXT4_DEFM_BLOCK_VALIDITY 0x0200
1815 #define EXT4_DEFM_DISCARD       0x0400
1816 #define EXT4_DEFM_NODELALLOC    0x0800
1817 
1818 /*
1819  * Default journal batch times
1820  */
1821 #define EXT4_DEF_MIN_BATCH_TIME 0
1822 #define EXT4_DEF_MAX_BATCH_TIME 15000 /* 15ms */
1823 
1824 /*
1825  * Minimum number of groups in a flexgroup before we separate out
1826  * directories into the first block group of a flexgroup
1827  */
1828 #define EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME 4
1829 
1830 /*
1831  * Structure of a directory entry
1832  */
1833 #define EXT4_NAME_LEN 255
1834 
1835 struct ext4_dir_entry {
1836         __le32  inode;                  /* Inode number */
1837         __le16  rec_len;                /* Directory entry length */
1838         __le16  name_len;               /* Name length */
1839         char    name[EXT4_NAME_LEN];    /* File name */
1840 };
1841 
1842 /*
1843  * The new version of the directory entry.  Since EXT4 structures are
1844  * stored in intel byte order, and the name_len field could never be
1845  * bigger than 255 chars, it's safe to reclaim the extra byte for the
1846  * file_type field.
1847  */
1848 struct ext4_dir_entry_2 {
1849         __le32  inode;                  /* Inode number */
1850         __le16  rec_len;                /* Directory entry length */
1851         __u8    name_len;               /* Name length */
1852         __u8    file_type;
1853         char    name[EXT4_NAME_LEN];    /* File name */
1854 };
1855 
1856 /*
1857  * This is a bogus directory entry at the end of each leaf block that
1858  * records checksums.
1859  */
1860 struct ext4_dir_entry_tail {
1861         __le32  det_reserved_zero1;     /* Pretend to be unused */
1862         __le16  det_rec_len;            /* 12 */
1863         __u8    det_reserved_zero2;     /* Zero name length */
1864         __u8    det_reserved_ft;        /* 0xDE, fake file type */
1865         __le32  det_checksum;           /* crc32c(uuid+inum+dirblock) */
1866 };
1867 
1868 #define EXT4_DIRENT_TAIL(block, blocksize) \
1869         ((struct ext4_dir_entry_tail *)(((void *)(block)) + \
1870                                         ((blocksize) - \
1871                                          sizeof(struct ext4_dir_entry_tail))))
1872 
1873 /*
1874  * Ext4 directory file types.  Only the low 3 bits are used.  The
1875  * other bits are reserved for now.
1876  */
1877 #define EXT4_FT_UNKNOWN         0
1878 #define EXT4_FT_REG_FILE        1
1879 #define EXT4_FT_DIR             2
1880 #define EXT4_FT_CHRDEV          3
1881 #define EXT4_FT_BLKDEV          4
1882 #define EXT4_FT_FIFO            5
1883 #define EXT4_FT_SOCK            6
1884 #define EXT4_FT_SYMLINK         7
1885 
1886 #define EXT4_FT_MAX             8
1887 
1888 #define EXT4_FT_DIR_CSUM        0xDE
1889 
1890 /*
1891  * EXT4_DIR_PAD defines the directory entries boundaries
1892  *
1893  * NOTE: It must be a multiple of 4
1894  */
1895 #define EXT4_DIR_PAD                    4
1896 #define EXT4_DIR_ROUND                  (EXT4_DIR_PAD - 1)
1897 #define EXT4_DIR_REC_LEN(name_len)      (((name_len) + 8 + EXT4_DIR_ROUND) & \
1898                                          ~EXT4_DIR_ROUND)
1899 #define EXT4_MAX_REC_LEN                ((1<<16)-1)
1900 
1901 /*
1902  * If we ever get support for fs block sizes > page_size, we'll need
1903  * to remove the #if statements in the next two functions...
1904  */
1905 static inline unsigned int
1906 ext4_rec_len_from_disk(__le16 dlen, unsigned blocksize)
1907 {
1908         unsigned len = le16_to_cpu(dlen);
1909 
1910 #if (PAGE_CACHE_SIZE >= 65536)
1911         if (len == EXT4_MAX_REC_LEN || len == 0)
1912                 return blocksize;
1913         return (len & 65532) | ((len & 3) << 16);
1914 #else
1915         return len;
1916 #endif
1917 }
1918 
1919 static inline __le16 ext4_rec_len_to_disk(unsigned len, unsigned blocksize)
1920 {
1921         if ((len > blocksize) || (blocksize > (1 << 18)) || (len & 3))
1922                 BUG();
1923 #if (PAGE_CACHE_SIZE >= 65536)
1924         if (len < 65536)
1925                 return cpu_to_le16(len);
1926         if (len == blocksize) {
1927                 if (blocksize == 65536)
1928                         return cpu_to_le16(EXT4_MAX_REC_LEN);
1929                 else
1930                         return cpu_to_le16(0);
1931         }
1932         return cpu_to_le16((len & 65532) | ((len >> 16) & 3));
1933 #else
1934         return cpu_to_le16(len);
1935 #endif
1936 }
1937 
1938 /*
1939  * Hash Tree Directory indexing
1940  * (c) Daniel Phillips, 2001
1941  */
1942 
1943 #define is_dx(dir) (ext4_has_feature_dir_index((dir)->i_sb) && \
1944                     ext4_test_inode_flag((dir), EXT4_INODE_INDEX))
1945 #define EXT4_DIR_LINK_MAX(dir) (!is_dx(dir) && (dir)->i_nlink >= EXT4_LINK_MAX)
1946 #define EXT4_DIR_LINK_EMPTY(dir) ((dir)->i_nlink == 2 || (dir)->i_nlink == 1)
1947 
1948 /* Legal values for the dx_root hash_version field: */
1949 
1950 #define DX_HASH_LEGACY          0
1951 #define DX_HASH_HALF_MD4        1
1952 #define DX_HASH_TEA             2
1953 #define DX_HASH_LEGACY_UNSIGNED 3
1954 #define DX_HASH_HALF_MD4_UNSIGNED       4
1955 #define DX_HASH_TEA_UNSIGNED            5
1956 
1957 static inline u32 ext4_chksum(struct ext4_sb_info *sbi, u32 crc,
1958                               const void *address, unsigned int length)
1959 {
1960         struct {
1961                 struct shash_desc shash;
1962                 char ctx[4];
1963         } desc;
1964         int err;
1965 
1966         BUG_ON(crypto_shash_descsize(sbi->s_chksum_driver)!=sizeof(desc.ctx));
1967 
1968         desc.shash.tfm = sbi->s_chksum_driver;
1969         desc.shash.flags = 0;
1970         *(u32 *)desc.ctx = crc;
1971 
1972         err = crypto_shash_update(&desc.shash, address, length);
1973         BUG_ON(err);
1974 
1975         return *(u32 *)desc.ctx;
1976 }
1977 
1978 #ifdef __KERNEL__
1979 
1980 /* hash info structure used by the directory hash */
1981 struct dx_hash_info
1982 {
1983         u32             hash;
1984         u32             minor_hash;
1985         int             hash_version;
1986         u32             *seed;
1987 };
1988 
1989 
1990 /* 32 and 64 bit signed EOF for dx directories */
1991 #define EXT4_HTREE_EOF_32BIT   ((1UL  << (32 - 1)) - 1)
1992 #define EXT4_HTREE_EOF_64BIT   ((1ULL << (64 - 1)) - 1)
1993 
1994 
1995 /*
1996  * Control parameters used by ext4_htree_next_block
1997  */
1998 #define HASH_NB_ALWAYS          1
1999 
2000 struct ext4_filename {
2001         const struct qstr *usr_fname;
2002         struct ext4_str disk_name;
2003         struct dx_hash_info hinfo;
2004 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2005         struct ext4_str crypto_buf;
2006 #endif
2007 };
2008 
2009 #define fname_name(p) ((p)->disk_name.name)
2010 #define fname_len(p)  ((p)->disk_name.len)
2011 
2012 /*
2013  * Describe an inode's exact location on disk and in memory
2014  */
2015 struct ext4_iloc
2016 {
2017         struct buffer_head *bh;
2018         unsigned long offset;
2019         ext4_group_t block_group;
2020 };
2021 
2022 static inline struct ext4_inode *ext4_raw_inode(struct ext4_iloc *iloc)
2023 {
2024         return (struct ext4_inode *) (iloc->bh->b_data + iloc->offset);
2025 }
2026 
2027 /*
2028  * This structure is stuffed into the struct file's private_data field
2029  * for directories.  It is where we put information so that we can do
2030  * readdir operations in hash tree order.
2031  */
2032 struct dir_private_info {
2033         struct rb_root  root;
2034         struct rb_node  *curr_node;
2035         struct fname    *extra_fname;
2036         loff_t          last_pos;
2037         __u32           curr_hash;
2038         __u32           curr_minor_hash;
2039         __u32           next_hash;
2040 };
2041 
2042 /* calculate the first block number of the group */
2043 static inline ext4_fsblk_t
2044 ext4_group_first_block_no(struct super_block *sb, ext4_group_t group_no)
2045 {
2046         return group_no * (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) +
2047                 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
2048 }
2049 
2050 /*
2051  * Special error return code only used by dx_probe() and its callers.
2052  */
2053 #define ERR_BAD_DX_DIR  (-(MAX_ERRNO - 1))
2054 
2055 /*
2056  * Timeout and state flag for lazy initialization inode thread.
2057  */
2058 #define EXT4_DEF_LI_WAIT_MULT                   10
2059 #define EXT4_DEF_LI_MAX_START_DELAY             5
2060 #define EXT4_LAZYINIT_QUIT                      0x0001
2061 #define EXT4_LAZYINIT_RUNNING                   0x0002
2062 
2063 /*
2064  * Lazy inode table initialization info
2065  */
2066 struct ext4_lazy_init {
2067         unsigned long           li_state;
2068         struct list_head        li_request_list;
2069         struct mutex            li_list_mtx;
2070 };
2071 
2072 struct ext4_li_request {
2073         struct super_block      *lr_super;
2074         struct ext4_sb_info     *lr_sbi;
2075         ext4_group_t            lr_next_group;
2076         struct list_head        lr_request;
2077         unsigned long           lr_next_sched;
2078         unsigned long           lr_timeout;
2079 };
2080 
2081 struct ext4_features {
2082         struct kobject f_kobj;
2083         struct completion f_kobj_unregister;
2084 };
2085 
2086 /*
2087  * This structure will be used for multiple mount protection. It will be
2088  * written into the block number saved in the s_mmp_block field in the
2089  * superblock. Programs that check MMP should assume that if
2090  * SEQ_FSCK (or any unknown code above SEQ_MAX) is present then it is NOT safe
2091  * to use the filesystem, regardless of how old the timestamp is.
2092  */
2093 #define EXT4_MMP_MAGIC     0x004D4D50U /* ASCII for MMP */
2094 #define EXT4_MMP_SEQ_CLEAN 0xFF4D4D50U /* mmp_seq value for clean unmount */
2095 #define EXT4_MMP_SEQ_FSCK  0xE24D4D50U /* mmp_seq value when being fscked */
2096 #define EXT4_MMP_SEQ_MAX   0xE24D4D4FU /* maximum valid mmp_seq value */
2097 
2098 struct mmp_struct {
2099         __le32  mmp_magic;              /* Magic number for MMP */
2100         __le32  mmp_seq;                /* Sequence no. updated periodically */
2101 
2102         /*
2103          * mmp_time, mmp_nodename & mmp_bdevname are only used for information
2104          * purposes and do not affect the correctness of the algorithm
2105          */
2106         __le64  mmp_time;               /* Time last updated */
2107         char    mmp_nodename[64];       /* Node which last updated MMP block */
2108         char    mmp_bdevname[32];       /* Bdev which last updated MMP block */
2109 
2110         /*
2111          * mmp_check_interval is used to verify if the MMP block has been
2112          * updated on the block device. The value is updated based on the
2113          * maximum time to write the MMP block during an update cycle.
2114          */
2115         __le16  mmp_check_interval;
2116 
2117         __le16  mmp_pad1;
2118         __le32  mmp_pad2[226];
2119         __le32  mmp_checksum;           /* crc32c(uuid+mmp_block) */
2120 };
2121 
2122 /* arguments passed to the mmp thread */
2123 struct mmpd_data {
2124         struct buffer_head *bh; /* bh from initial read_mmp_block() */
2125         struct super_block *sb;  /* super block of the fs */
2126 };
2127 
2128 /*
2129  * Check interval multiplier
2130  * The MMP block is written every update interval and initially checked every
2131  * update interval x the multiplier (the value is then adapted based on the
2132  * write latency). The reason is that writes can be delayed under load and we
2133  * don't want readers to incorrectly assume that the filesystem is no longer
2134  * in use.
2135  */
2136 #define EXT4_MMP_CHECK_MULT             2UL
2137 
2138 /*
2139  * Minimum interval for MMP checking in seconds.
2140  */
2141 #define EXT4_MMP_MIN_CHECK_INTERVAL     5UL
2142 
2143 /*
2144  * Maximum interval for MMP checking in seconds.
2145  */
2146 #define EXT4_MMP_MAX_CHECK_INTERVAL     300UL
2147 
2148 /*
2149  * Function prototypes
2150  */
2151 
2152 /*
2153  * Ok, these declarations are also in <linux/kernel.h> but none of the
2154  * ext4 source programs needs to include it so they are duplicated here.
2155  */
2156 # define NORET_TYPE     /**/
2157 # define ATTRIB_NORET   __attribute__((noreturn))
2158 # define NORET_AND      noreturn,
2159 
2160 /* bitmap.c */
2161 extern unsigned int ext4_count_free(char *bitmap, unsigned numchars);
2162 void ext4_inode_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
2163                                 struct ext4_group_desc *gdp,
2164                                 struct buffer_head *bh, int sz);
2165 int ext4_inode_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
2166                                   struct ext4_group_desc *gdp,
2167                                   struct buffer_head *bh, int sz);
2168 void ext4_block_bitmap_csum_set(struct super_block *sb, ext4_group_t group,
2169                                 struct ext4_group_desc *gdp,
2170                                 struct buffer_head *bh);
2171 int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
2172                                   struct ext4_group_desc *gdp,
2173                                   struct buffer_head *bh);
2174 
2175 /* balloc.c */
2176 extern void ext4_get_group_no_and_offset(struct super_block *sb,
2177                                          ext4_fsblk_t blocknr,
2178                                          ext4_group_t *blockgrpp,
2179                                          ext4_grpblk_t *offsetp);
2180 extern ext4_group_t ext4_get_group_number(struct super_block *sb,
2181                                           ext4_fsblk_t block);
2182 
2183 extern unsigned int ext4_block_group(struct super_block *sb,
2184                         ext4_fsblk_t blocknr);
2185 extern ext4_grpblk_t ext4_block_group_offset(struct super_block *sb,
2186                         ext4_fsblk_t blocknr);
2187 extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
2188 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
2189                         ext4_group_t group);
2190 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
2191                                          ext4_fsblk_t goal,
2192                                          unsigned int flags,
2193                                          unsigned long *count,
2194                                          int *errp);
2195 extern int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
2196                                     s64 nclusters, unsigned int flags);
2197 extern ext4_fsblk_t ext4_count_free_clusters(struct super_block *);
2198 extern void ext4_check_blocks_bitmap(struct super_block *);
2199 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
2200                                                     ext4_group_t block_group,
2201                                                     struct buffer_head ** bh);
2202 extern int ext4_should_retry_alloc(struct super_block *sb, int *retries);
2203 
2204 extern struct buffer_head *ext4_read_block_bitmap_nowait(struct super_block *sb,
2205                                                 ext4_group_t block_group);
2206 extern int ext4_wait_block_bitmap(struct super_block *sb,
2207                                   ext4_group_t block_group,
2208                                   struct buffer_head *bh);
2209 extern struct buffer_head *ext4_read_block_bitmap(struct super_block *sb,
2210                                                   ext4_group_t block_group);
2211 extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
2212                                               ext4_group_t block_group,
2213                                               struct ext4_group_desc *gdp);
2214 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
2215 
2216 /* crypto_policy.c */
2217 int ext4_is_child_context_consistent_with_parent(struct inode *parent,
2218                                                  struct inode *child);
2219 int ext4_inherit_context(struct inode *parent, struct inode *child);
2220 void ext4_to_hex(char *dst, char *src, size_t src_size);
2221 int ext4_process_policy(const struct ext4_encryption_policy *policy,
2222                         struct inode *inode);
2223 int ext4_get_policy(struct inode *inode,
2224                     struct ext4_encryption_policy *policy);
2225 
2226 /* crypto.c */
2227 extern struct kmem_cache *ext4_crypt_info_cachep;
2228 bool ext4_valid_contents_enc_mode(uint32_t mode);
2229 uint32_t ext4_validate_encryption_key_size(uint32_t mode, uint32_t size);
2230 extern struct workqueue_struct *ext4_read_workqueue;
2231 struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode);
2232 void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx);
2233 void ext4_restore_control_page(struct page *data_page);
2234 struct page *ext4_encrypt(struct inode *inode,
2235                           struct page *plaintext_page);
2236 int ext4_decrypt(struct page *page);
2237 int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex);
2238 
2239 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2240 int ext4_init_crypto(void);
2241 void ext4_exit_crypto(void);
2242 static inline int ext4_sb_has_crypto(struct super_block *sb)
2243 {
2244         return ext4_has_feature_encrypt(sb);
2245 }
2246 #else
2247 static inline int ext4_init_crypto(void) { return 0; }
2248 static inline void ext4_exit_crypto(void) { }
2249 static inline int ext4_sb_has_crypto(struct super_block *sb)
2250 {
2251         return 0;
2252 }
2253 #endif
2254 
2255 /* crypto_fname.c */
2256 bool ext4_valid_filenames_enc_mode(uint32_t mode);
2257 u32 ext4_fname_crypto_round_up(u32 size, u32 blksize);
2258 unsigned ext4_fname_encrypted_size(struct inode *inode, u32 ilen);
2259 int ext4_fname_crypto_alloc_buffer(struct inode *inode,
2260                                    u32 ilen, struct ext4_str *crypto_str);
2261 int _ext4_fname_disk_to_usr(struct inode *inode,
2262                             struct dx_hash_info *hinfo,
2263                             const struct ext4_str *iname,
2264                             struct ext4_str *oname);
2265 int ext4_fname_disk_to_usr(struct inode *inode,
2266                            struct dx_hash_info *hinfo,
2267                            const struct ext4_dir_entry_2 *de,
2268                            struct ext4_str *oname);
2269 int ext4_fname_usr_to_disk(struct inode *inode,
2270                            const struct qstr *iname,
2271                            struct ext4_str *oname);
2272 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2273 void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str);
2274 int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
2275                               int lookup, struct ext4_filename *fname);
2276 void ext4_fname_free_filename(struct ext4_filename *fname);
2277 #else
2278 static inline
2279 int ext4_setup_fname_crypto(struct inode *inode)
2280 {
2281         return 0;
2282 }
2283 static inline void ext4_fname_crypto_free_buffer(struct ext4_str *p) { }
2284 static inline int ext4_fname_setup_filename(struct inode *dir,
2285                                      const struct qstr *iname,
2286                                      int lookup, struct ext4_filename *fname)
2287 {
2288         fname->usr_fname = iname;
2289         fname->disk_name.name = (unsigned char *) iname->name;
2290         fname->disk_name.len = iname->len;
2291         return 0;
2292 }
2293 static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
2294 #endif
2295 
2296 
2297 /* crypto_key.c */
2298 void ext4_free_crypt_info(struct ext4_crypt_info *ci);
2299 void ext4_free_encryption_info(struct inode *inode, struct ext4_crypt_info *ci);
2300 int _ext4_get_encryption_info(struct inode *inode);
2301 
2302 #ifdef CONFIG_EXT4_FS_ENCRYPTION
2303 int ext4_has_encryption_key(struct inode *inode);
2304 
2305 static inline int ext4_get_encryption_info(struct inode *inode)
2306 {
2307         struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
2308 
2309         if (!ci ||
2310             (ci->ci_keyring_key &&
2311              (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
2312                                            (1 << KEY_FLAG_REVOKED) |
2313                                            (1 << KEY_FLAG_DEAD)))))
2314                 return _ext4_get_encryption_info(inode);
2315         return 0;
2316 }
2317 
2318 static inline struct ext4_crypt_info *ext4_encryption_info(struct inode *inode)
2319 {
2320         return EXT4_I(inode)->i_crypt_info;
2321 }
2322 
2323 #else
2324 static inline int ext4_has_encryption_key(struct inode *inode)
2325 {
2326         return 0;
2327 }
2328 static inline int ext4_get_encryption_info(struct inode *inode)
2329 {
2330         return 0;
2331 }
2332 static inline struct ext4_crypt_info *ext4_encryption_info(struct inode *inode)
2333 {
2334         return NULL;
2335 }
2336 #endif
2337 
2338 
2339 /* dir.c */
2340 extern int __ext4_check_dir_entry(const char *, unsigned int, struct inode *,
2341                                   struct file *,
2342                                   struct ext4_dir_entry_2 *,
2343                                   struct buffer_head *, char *, int,
2344                                   unsigned int);
2345 #define ext4_check_dir_entry(dir, filp, de, bh, buf, size, offset)      \
2346         unlikely(__ext4_check_dir_entry(__func__, __LINE__, (dir), (filp), \
2347                                         (de), (bh), (buf), (size), (offset)))
2348 extern int ext4_htree_store_dirent(struct file *dir_file, __u32 hash,
2349                                 __u32 minor_hash,
2350                                 struct ext4_dir_entry_2 *dirent,
2351                                 struct ext4_str *ent_name);
2352 extern void ext4_htree_free_dir_info(struct dir_private_info *p);
2353 extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
2354                              struct buffer_head *bh,
2355                              void *buf, int buf_size,
2356                              struct ext4_filename *fname,
2357                              struct ext4_dir_entry_2 **dest_de);
2358 int ext4_insert_dentry(struct inode *dir,
2359                        struct inode *inode,
2360                        struct ext4_dir_entry_2 *de,
2361                        int buf_size,
2362                        struct ext4_filename *fname);
2363 static inline void ext4_update_dx_flag(struct inode *inode)
2364 {
2365         if (!ext4_has_feature_dir_index(inode->i_sb))
2366                 ext4_clear_inode_flag(inode, EXT4_INODE_INDEX);
2367 }
2368 static unsigned char ext4_filetype_table[] = {
2369         DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
2370 };
2371 
2372 static inline  unsigned char get_dtype(struct super_block *sb, int filetype)
2373 {
2374         if (!ext4_has_feature_filetype(sb) || filetype >= EXT4_FT_MAX)
2375                 return DT_UNKNOWN;
2376 
2377         return ext4_filetype_table[filetype];
2378 }
2379 extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
2380                              void *buf, int buf_size);
2381 
2382 /* fsync.c */
2383 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);
2384 
2385 /* hash.c */
2386 extern int ext4fs_dirhash(const char *name, int len, struct
2387                           dx_hash_info *hinfo);
2388 
2389 /* ialloc.c */
2390 extern struct inode *__ext4_new_inode(handle_t *, struct inode *, umode_t,
2391                                       const struct qstr *qstr, __u32 goal,
2392                                       uid_t *owner, int handle_type,
2393                                       unsigned int line_no, int nblocks);
2394 
2395 #define ext4_new_inode(handle, dir, mode, qstr, goal, owner) \
2396         __ext4_new_inode((handle), (dir), (mode), (qstr), (goal), (owner), \
2397                          0, 0, 0)
2398 #define ext4_new_inode_start_handle(dir, mode, qstr, goal, owner, \
2399                                     type, nblocks)                  \
2400         __ext4_new_inode(NULL, (dir), (mode), (qstr), (goal), (owner), \
2401                          (type), __LINE__, (nblocks))
2402 
2403 
2404 extern void ext4_free_inode(handle_t *, struct inode *);
2405 extern struct inode * ext4_orphan_get(struct super_block *, unsigned long);
2406 extern unsigned long ext4_count_free_inodes(struct super_block *);
2407 extern unsigned long ext4_count_dirs(struct super_block *);
2408 extern void ext4_check_inodes_bitmap(struct super_block *);
2409 extern void ext4_mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
2410 extern int ext4_init_inode_table(struct super_block *sb,
2411                                  ext4_group_t group, int barrier);
2412 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
2413 
2414 /* mballoc.c */
2415 extern const struct file_operations ext4_seq_mb_groups_fops;
2416 extern long ext4_mb_stats;
2417 extern long ext4_mb_max_to_scan;
2418 extern int ext4_mb_init(struct super_block *);
2419 extern int ext4_mb_release(struct super_block *);
2420 extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
2421                                 struct ext4_allocation_request *, int *);
2422 extern int ext4_mb_reserve_blocks(struct super_block *, int);
2423 extern void ext4_discard_preallocations(struct inode *);
2424 extern int __init ext4_init_mballoc(void);
2425 extern void ext4_exit_mballoc(void);
2426 extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
2427                              struct buffer_head *bh, ext4_fsblk_t block,
2428                              unsigned long count, int flags);
2429 extern int ext4_mb_alloc_groupinfo(struct super_block *sb,
2430                                    ext4_group_t ngroups);
2431 extern int ext4_mb_add_groupinfo(struct super_block *sb,
2432                 ext4_group_t i, struct ext4_group_desc *desc);
2433 extern int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
2434                                 ext4_fsblk_t block, unsigned long count);
2435 extern int ext4_trim_fs(struct super_block *, struct fstrim_range *);
2436 
2437 /* inode.c */
2438 int ext4_inode_is_fast_symlink(struct inode *inode);
2439 struct buffer_head *ext4_getblk(handle_t *, struct inode *, ext4_lblk_t, int);
2440 struct buffer_head *ext4_bread(handle_t *, struct inode *, ext4_lblk_t, int);
2441 int ext4_get_block_write(struct inode *inode, sector_t iblock,
2442                          struct buffer_head *bh_result, int create);
2443 int ext4_get_block_dax(struct inode *inode, sector_t iblock,
2444                          struct buffer_head *bh_result, int create);
2445 int ext4_get_block(struct inode *inode, sector_t iblock,
2446                                 struct buffer_head *bh_result, int create);
2447 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
2448                            struct buffer_head *bh, int create);
2449 int ext4_walk_page_buffers(handle_t *handle,
2450                            struct buffer_head *head,
2451                            unsigned from,
2452                            unsigned to,
2453                            int *partial,
2454                            int (*fn)(handle_t *handle,
2455                                      struct buffer_head *bh));
2456 int do_journal_get_write_access(handle_t *handle,
2457                                 struct buffer_head *bh);
2458 #define FALL_BACK_TO_NONDELALLOC 1
2459 #define CONVERT_INLINE_DATA      2
2460 
2461 extern struct inode *ext4_iget(struct super_block *, unsigned long);
2462 extern struct inode *ext4_iget_normal(struct super_block *, unsigned long);
2463 extern int  ext4_write_inode(struct inode *, struct writeback_control *);
2464 extern int  ext4_setattr(struct dentry *, struct iattr *);
2465 extern int  ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
2466                                 struct kstat *stat);
2467 extern void ext4_evict_inode(struct inode *);
2468 extern void ext4_clear_inode(struct inode *);
2469 extern int  ext4_sync_inode(handle_t *, struct inode *);
2470 extern void ext4_dirty_inode(struct inode *, int);
2471 extern int ext4_change_inode_journal_flag(struct inode *, int);
2472 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
2473 extern int ext4_inode_attach_jinode(struct inode *inode);
2474 extern int ext4_can_truncate(struct inode *inode);
2475 extern void ext4_truncate(struct inode *);
2476 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
2477 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
2478 extern void ext4_set_inode_flags(struct inode *);
2479 extern void ext4_get_inode_flags(struct ext4_inode_info *);
2480 extern int ext4_alloc_da_blocks(struct inode *inode);
2481 extern void ext4_set_aops(struct inode *inode);
2482 extern int ext4_writepage_trans_blocks(struct inode *);
2483 extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks);
2484 extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
2485                              loff_t lstart, loff_t lend);
2486 extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf);
2487 extern qsize_t *ext4_get_reserved_space(struct inode *inode);
2488 extern void ext4_da_update_reserve_space(struct inode *inode,
2489                                         int used, int quota_claim);
2490 
2491 /* indirect.c */
2492 extern int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
2493                                 struct ext4_map_blocks *map, int flags);
2494 extern ssize_t ext4_ind_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
2495                                   loff_t offset);
2496 extern int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock);
2497 extern int ext4_ind_trans_blocks(struct inode *inode, int nrblocks);
2498 extern void ext4_ind_truncate(handle_t *, struct inode *inode);
2499 extern int ext4_ind_remove_space(handle_t *handle, struct inode *inode,
2500                                  ext4_lblk_t start, ext4_lblk_t end);
2501 
2502 /* ioctl.c */
2503 extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
2504 extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);
2505 
2506 /* migrate.c */
2507 extern int ext4_ext_migrate(struct inode *);
2508 extern int ext4_ind_migrate(struct inode *inode);
2509 
2510 /* namei.c */
2511 extern int ext4_dirent_csum_verify(struct inode *inode,
2512                                    struct ext4_dir_entry *dirent);
2513 extern int ext4_orphan_add(handle_t *, struct inode *);
2514 extern int ext4_orphan_del(handle_t *, struct inode *);
2515 extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
2516                                 __u32 start_minor_hash, __u32 *next_hash);
2517 extern int ext4_search_dir(struct buffer_head *bh,
2518                            char *search_buf,
2519                            int buf_size,
2520                            struct inode *dir,
2521                            struct ext4_filename *fname,
2522                            const struct qstr *d_name,
2523                            unsigned int offset,
2524                            struct ext4_dir_entry_2 **res_dir);
2525 extern int ext4_generic_delete_entry(handle_t *handle,
2526                                      struct inode *dir,
2527                                      struct ext4_dir_entry_2 *de_del,
2528                                      struct buffer_head *bh,
2529                                      void *entry_buf,
2530                                      int buf_size,
2531                                      int csum_size);
2532 extern int ext4_empty_dir(struct inode *inode);
2533 
2534 /* resize.c */
2535 extern int ext4_group_add(struct super_block *sb,
2536                                 struct ext4_new_group_data *input);
2537 extern int ext4_group_extend(struct super_block *sb,
2538                                 struct ext4_super_block *es,
2539                                 ext4_fsblk_t n_blocks_count);
2540 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
2541 
2542 /* super.c */
2543 extern int ext4_seq_options_show(struct seq_file *seq, void *offset);
2544 extern int ext4_calculate_overhead(struct super_block *sb);
2545 extern void ext4_superblock_csum_set(struct super_block *sb);
2546 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
2547 extern void *ext4_kvzalloc(size_t size, gfp_t flags);
2548 extern int ext4_alloc_flex_bg_array(struct super_block *sb,
2549                                     ext4_group_t ngroup);
2550 extern const char *ext4_decode_error(struct super_block *sb, int errno,
2551                                      char nbuf[16]);
2552 
2553 extern __printf(4, 5)
2554 void __ext4_error(struct super_block *, const char *, unsigned int,
2555                   const char *, ...);
2556 extern __printf(5, 6)
2557 void __ext4_error_inode(struct inode *, const char *, unsigned int, ext4_fsblk_t,
2558                       const char *, ...);
2559 extern __printf(5, 6)
2560 void __ext4_error_file(struct file *, const char *, unsigned int, ext4_fsblk_t,
2561                      const char *, ...);
2562 extern void __ext4_std_error(struct super_block *, const char *,
2563                              unsigned int, int);
2564 extern __printf(4, 5)
2565 void __ext4_abort(struct super_block *, const char *, unsigned int,
2566                   const char *, ...);
2567 extern __printf(4, 5)
2568 void __ext4_warning(struct super_block *, const char *, unsigned int,
2569                     const char *, ...);
2570 extern __printf(4, 5)
2571 void __ext4_warning_inode(const struct inode *inode, const char *function,
2572                           unsigned int line, const char *fmt, ...);
2573 extern __printf(3, 4)
2574 void __ext4_msg(struct super_block *, const char *, const char *, ...);
2575 extern void __dump_mmp_msg(struct super_block *, struct mmp_struct *mmp,
2576                            const char *, unsigned int, const char *);
2577 extern __printf(7, 8)
2578 void __ext4_grp_locked_error(const char *, unsigned int,
2579                              struct super_block *, ext4_group_t,
2580                              unsigned long, ext4_fsblk_t,
2581                              const char *, ...);
2582 
2583 #define EXT4_ERROR_INODE(inode, fmt, a...) \
2584         ext4_error_inode((inode), __func__, __LINE__, 0, (fmt), ## a)
2585 
2586 #define EXT4_ERROR_INODE_BLOCK(inode, block, fmt, a...)                 \
2587         ext4_error_inode((inode), __func__, __LINE__, (block), (fmt), ## a)
2588 
2589 #define EXT4_ERROR_FILE(file, block, fmt, a...)                         \
2590         ext4_error_file((file), __func__, __LINE__, (block), (fmt), ## a)
2591 
2592 #ifdef CONFIG_PRINTK
2593 
2594 #define ext4_error_inode(inode, func, line, block, fmt, ...)            \
2595         __ext4_error_inode(inode, func, line, block, fmt, ##__VA_ARGS__)
2596 #define ext4_error_file(file, func, line, block, fmt, ...)              \
2597         __ext4_error_file(file, func, line, block, fmt, ##__VA_ARGS__)
2598 #define ext4_error(sb, fmt, ...)                                        \
2599         __ext4_error(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2600 #define ext4_abort(sb, fmt, ...)                                        \
2601         __ext4_abort(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2602 #define ext4_warning(sb, fmt, ...)                                      \
2603         __ext4_warning(sb, __func__, __LINE__, fmt, ##__VA_ARGS__)
2604 #define ext4_warning_inode(inode, fmt, ...)                             \
2605         __ext4_warning_inode(inode, __func__, __LINE__, fmt, ##__VA_ARGS__)
2606 #define ext4_msg(sb, level, fmt, ...)                           \
2607         __ext4_msg(sb, level, fmt, ##__VA_ARGS__)
2608 #define dump_mmp_msg(sb, mmp, msg)                                      \
2609         __dump_mmp_msg(sb, mmp, __func__, __LINE__, msg)
2610 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)            \
2611         __ext4_grp_locked_error(__func__, __LINE__, sb, grp, ino, block, \
2612                                 fmt, ##__VA_ARGS__)
2613 
2614 #else
2615 
2616 #define ext4_error_inode(inode, func, line, block, fmt, ...)            \
2617 do {                                                                    \
2618         no_printk(fmt, ##__VA_ARGS__);                                  \
2619         __ext4_error_inode(inode, "", 0, block, " ");                   \
2620 } while (0)
2621 #define ext4_error_file(file, func, line, block, fmt, ...)              \
2622 do {                                                                    \
2623         no_printk(fmt, ##__VA_ARGS__);                                  \
2624         __ext4_error_file(file, "", 0, block, " ");                     \
2625 } while (0)
2626 #define ext4_error(sb, fmt, ...)                                        \
2627 do {                                                                    \
2628         no_printk(fmt, ##__VA_ARGS__);                                  \
2629         __ext4_error(sb, "", 0, " ");                                   \
2630 } while (0)
2631 #define ext4_abort(sb, fmt, ...)                                        \
2632 do {                                                                    \
2633         no_printk(fmt, ##__VA_ARGS__);                                  \
2634         __ext4_abort(sb, "", 0, " ");                                   \
2635 } while (0)
2636 #define ext4_warning(sb, fmt, ...)                                      \
2637 do {                                                                    \
2638         no_printk(fmt, ##__VA_ARGS__);                                  \
2639         __ext4_warning(sb, "", 0, " ");                                 \
2640 } while (0)
2641 #define ext4_warning_inode(inode, fmt, ...)                             \
2642 do {                                                                    \
2643         no_printk(fmt, ##__VA_ARGS__);                                  \
2644         __ext4_warning_inode(inode, "", 0, " ");                        \
2645 } while (0)
2646 #define ext4_msg(sb, level, fmt, ...)                                   \
2647 do {                                                                    \
2648         no_printk(fmt, ##__VA_ARGS__);                                  \
2649         __ext4_msg(sb, "", " ");                                        \
2650 } while (0)
2651 #define dump_mmp_msg(sb, mmp, msg)                                      \
2652         __dump_mmp_msg(sb, mmp, "", 0, "")
2653 #define ext4_grp_locked_error(sb, grp, ino, block, fmt, ...)            \
2654 do {                                                                    \
2655         no_printk(fmt, ##__VA_ARGS__);                          \
2656         __ext4_grp_locked_error("", 0, sb, grp, ino, block, " ");       \
2657 } while (0)
2658 
2659 #endif
2660 
2661 extern void ext4_update_dynamic_rev(struct super_block *sb);
2662 extern int ext4_update_compat_feature(handle_t *handle, struct super_block *sb,
2663                                         __u32 compat);
2664 extern int ext4_update_rocompat_feature(handle_t *handle,
2665                                         struct super_block *sb, __u32 rocompat);
2666 extern int ext4_update_incompat_feature(handle_t *handle,
2667                                         struct super_block *sb, __u32 incompat);
2668 extern ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
2669                                       struct ext4_group_desc *bg);
2670 extern ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
2671                                       struct ext4_group_desc *bg);
2672 extern ext4_fsblk_t ext4_inode_table(struct super_block *sb,
2673                                      struct ext4_group_desc *bg);
2674 extern __u32 ext4_free_group_clusters(struct super_block *sb,
2675                                       struct ext4_group_desc *bg);
2676 extern __u32 ext4_free_inodes_count(struct super_block *sb,
2677                                  struct ext4_group_desc *bg);
2678 extern __u32 ext4_used_dirs_count(struct super_block *sb,
2679                                 struct ext4_group_desc *bg);
2680 extern __u32 ext4_itable_unused_count(struct super_block *sb,
2681                                    struct ext4_group_desc *bg);
2682 extern void ext4_block_bitmap_set(struct super_block *sb,
2683                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2684 extern void ext4_inode_bitmap_set(struct super_block *sb,
2685                                   struct ext4_group_desc *bg, ext4_fsblk_t blk);
2686 extern void ext4_inode_table_set(struct super_block *sb,
2687                                  struct ext4_group_desc *bg, ext4_fsblk_t blk);
2688 extern void ext4_free_group_clusters_set(struct super_block *sb,
2689                                          struct ext4_group_desc *bg,
2690                                          __u32 count);
2691 extern void ext4_free_inodes_set(struct super_block *sb,
2692                                 struct ext4_group_desc *bg, __u32 count);
2693 extern void ext4_used_dirs_set(struct super_block *sb,
2694                                 struct ext4_group_desc *bg, __u32 count);
2695 extern void ext4_itable_unused_set(struct super_block *sb,
2696                                    struct ext4_group_desc *bg, __u32 count);
2697 extern int ext4_group_desc_csum_verify(struct super_block *sb, __u32 group,
2698                                        struct ext4_group_desc *gdp);
2699 extern void ext4_group_desc_csum_set(struct super_block *sb, __u32 group,
2700                                      struct ext4_group_desc *gdp);
2701 extern int ext4_register_li_request(struct super_block *sb,
2702                                     ext4_group_t first_not_zeroed);
2703 
2704 static inline int ext4_has_group_desc_csum(struct super_block *sb)
2705 {
2706         return ext4_has_feature_gdt_csum(sb) ||
2707                EXT4_SB(sb)->s_chksum_driver != NULL;
2708 }
2709 
2710 static inline int ext4_has_metadata_csum(struct super_block *sb)
2711 {
2712         WARN_ON_ONCE(ext4_has_feature_metadata_csum(sb) &&
2713                      !EXT4_SB(sb)->s_chksum_driver);
2714 
2715         return (EXT4_SB(sb)->s_chksum_driver != NULL);
2716 }
2717 static inline ext4_fsblk_t ext4_blocks_count(struct ext4_super_block *es)
2718 {
2719         return ((ext4_fsblk_t)le32_to_cpu(es->s_blocks_count_hi) << 32) |
2720                 le32_to_cpu(es->s_blocks_count_lo);
2721 }
2722 
2723 static inline ext4_fsblk_t ext4_r_blocks_count(struct ext4_super_block *es)
2724 {
2725         return ((ext4_fsblk_t)le32_to_cpu(es->s_r_blocks_count_hi) << 32) |
2726                 le32_to_cpu(es->s_r_blocks_count_lo);
2727 }
2728 
2729 static inline ext4_fsblk_t ext4_free_blocks_count(struct ext4_super_block *es)
2730 {
2731         return ((ext4_fsblk_t)le32_to_cpu(es->s_free_blocks_count_hi) << 32) |
2732                 le32_to_cpu(es->s_free_blocks_count_lo);
2733 }
2734 
2735 static inline void ext4_blocks_count_set(struct ext4_super_block *es,
2736                                          ext4_fsblk_t blk)
2737 {
2738         es->s_blocks_count_lo = cpu_to_le32((u32)blk);
2739         es->s_blocks_count_hi = cpu_to_le32(blk >> 32);
2740 }
2741 
2742 static inline void ext4_free_blocks_count_set(struct ext4_super_block *es,
2743                                               ext4_fsblk_t blk)
2744 {
2745         es->s_free_blocks_count_lo = cpu_to_le32((u32)blk);
2746         es->s_free_blocks_count_hi = cpu_to_le32(blk >> 32);
2747 }
2748 
2749 static inline void ext4_r_blocks_count_set(struct ext4_super_block *es,
2750                                            ext4_fsblk_t blk)
2751 {
2752         es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
2753         es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
2754 }
2755 
2756 static inline loff_t ext4_isize(struct ext4_inode *raw_inode)
2757 {
2758         if (S_ISREG(le16_to_cpu(raw_inode->i_mode)))
2759                 return ((loff_t)le32_to_cpu(raw_inode->i_size_high) << 32) |
2760                         le32_to_cpu(raw_inode->i_size_lo);
2761         else
2762                 return (loff_t) le32_to_cpu(raw_inode->i_size_lo);
2763 }
2764 
2765 static inline void ext4_isize_set(struct ext4_inode *raw_inode, loff_t i_size)
2766 {
2767         raw_inode->i_size_lo = cpu_to_le32(i_size);
2768         raw_inode->i_size_high = cpu_to_le32(i_size >> 32);
2769 }
2770 
2771 static inline
2772 struct ext4_group_info *ext4_get_group_info(struct super_block *sb,
2773                                             ext4_group_t group)
2774 {
2775          struct ext4_group_info ***grp_info;
2776          long indexv, indexh;
2777          BUG_ON(group >= EXT4_SB(sb)->s_groups_count);
2778          grp_info = EXT4_SB(sb)->s_group_info;
2779          indexv = group >> (EXT4_DESC_PER_BLOCK_BITS(sb));
2780          indexh = group & ((EXT4_DESC_PER_BLOCK(sb)) - 1);
2781          return grp_info[indexv][indexh];
2782 }
2783 
2784 /*
2785  * Reading s_groups_count requires using smp_rmb() afterwards.  See
2786  * the locking protocol documented in the comments of ext4_group_add()
2787  * in resize.c
2788  */
2789 static inline ext4_group_t ext4_get_groups_count(struct super_block *sb)
2790 {
2791         ext4_group_t    ngroups = EXT4_SB(sb)->s_groups_count;
2792 
2793         smp_rmb();
2794         return ngroups;
2795 }
2796 
2797 static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi,
2798                                              ext4_group_t block_group)
2799 {
2800         return block_group >> sbi->s_log_groups_per_flex;
2801 }
2802 
2803 static inline unsigned int ext4_flex_bg_size(struct ext4_sb_info *sbi)
2804 {
2805         return 1 << sbi->s_log_groups_per_flex;
2806 }
2807 
2808 #define ext4_std_error(sb, errno)                               \
2809 do {                                                            \
2810         if ((errno))                                            \
2811                 __ext4_std_error((sb), __func__, __LINE__, (errno));    \
2812 } while (0)
2813 
2814 #ifdef CONFIG_SMP
2815 /* Each CPU can accumulate percpu_counter_batch clusters in their local
2816  * counters. So we need to make sure we have free clusters more
2817  * than percpu_counter_batch  * nr_cpu_ids. Also add a window of 4 times.
2818  */
2819 #define EXT4_FREECLUSTERS_WATERMARK (4 * (percpu_counter_batch * nr_cpu_ids))
2820 #else
2821 #define EXT4_FREECLUSTERS_WATERMARK 0
2822 #endif
2823 
2824 /* Update i_disksize. Requires i_mutex to avoid races with truncate */
2825 static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
2826 {
2827         WARN_ON_ONCE(S_ISREG(inode->i_mode) &&
2828                      !mutex_is_locked(&inode->i_mutex));
2829         down_write(&EXT4_I(inode)->i_data_sem);
2830         if (newsize > EXT4_I(inode)->i_disksize)
2831                 EXT4_I(inode)->i_disksize = newsize;
2832         up_write(&EXT4_I(inode)->i_data_sem);
2833 }
2834 
2835 /* Update i_size, i_disksize. Requires i_mutex to avoid races with truncate */
2836 static inline int ext4_update_inode_size(struct inode *inode, loff_t newsize)
2837 {
2838         int changed = 0;
2839 
2840         if (newsize > inode->i_size) {
2841                 i_size_write(inode, newsize);
2842                 changed = 1;
2843         }
2844         if (newsize > EXT4_I(inode)->i_disksize) {
2845                 ext4_update_i_disksize(inode, newsize);
2846                 changed |= 2;
2847         }
2848         return changed;
2849 }
2850 
2851 struct ext4_group_info {
2852         unsigned long   bb_state;
2853         struct rb_root  bb_free_root;
2854         ext4_grpblk_t   bb_first_free;  /* first free block */
2855         ext4_grpblk_t   bb_free;        /* total free blocks */
2856         ext4_grpblk_t   bb_fragments;   /* nr of freespace fragments */
2857         ext4_grpblk_t   bb_largest_free_order;/* order of largest frag in BG */
2858         struct          list_head bb_prealloc_list;
2859 #ifdef DOUBLE_CHECK
2860         void            *bb_bitmap;
2861 #endif
2862         struct rw_semaphore alloc_sem;
2863         ext4_grpblk_t   bb_counters[];  /* Nr of free power-of-two-block
2864                                          * regions, index is order.
2865                                          * bb_counters[3] = 5 means
2866                                          * 5 free 8-block regions. */
2867 };
2868 
2869 #define EXT4_GROUP_INFO_NEED_INIT_BIT           0
2870 #define EXT4_GROUP_INFO_WAS_TRIMMED_BIT         1
2871 #define EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT     2
2872 #define EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT     3
2873 
2874 #define EXT4_MB_GRP_NEED_INIT(grp)      \
2875         (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
2876 #define EXT4_MB_GRP_BBITMAP_CORRUPT(grp)        \
2877         (test_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2878 #define EXT4_MB_GRP_IBITMAP_CORRUPT(grp)        \
2879         (test_bit(EXT4_GROUP_INFO_IBITMAP_CORRUPT_BIT, &((grp)->bb_state)))
2880 
2881 #define EXT4_MB_GRP_WAS_TRIMMED(grp)    \
2882         (test_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2883 #define EXT4_MB_GRP_SET_TRIMMED(grp)    \
2884         (set_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2885 #define EXT4_MB_GRP_CLEAR_TRIMMED(grp)  \
2886         (clear_bit(EXT4_GROUP_INFO_WAS_TRIMMED_BIT, &((grp)->bb_state)))
2887 
2888 #define EXT4_MAX_CONTENTION             8
2889 #define EXT4_CONTENTION_THRESHOLD       2
2890 
2891 static inline spinlock_t *ext4_group_lock_ptr(struct super_block *sb,
2892                                               ext4_group_t group)
2893 {
2894         return bgl_lock_ptr(EXT4_SB(sb)->s_blockgroup_lock, group);
2895 }
2896 
2897 /*
2898  * Returns true if the filesystem is busy enough that attempts to
2899  * access the block group locks has run into contention.
2900  */
2901 static inline int ext4_fs_is_busy(struct ext4_sb_info *sbi)
2902 {
2903         return (atomic_read(&sbi->s_lock_busy) > EXT4_CONTENTION_THRESHOLD);
2904 }
2905 
2906 static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
2907 {
2908         spinlock_t *lock = ext4_group_lock_ptr(sb, group);
2909         if (spin_trylock(lock))
2910                 /*
2911                  * We're able to grab the lock right away, so drop the
2912                  * lock contention counter.
2913                  */
2914                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, -1, 0);
2915         else {
2916                 /*
2917                  * The lock is busy, so bump the contention counter,
2918                  * and then wait on the spin lock.
2919                  */
2920                 atomic_add_unless(&EXT4_SB(sb)->s_lock_busy, 1,
2921                                   EXT4_MAX_CONTENTION);
2922                 spin_lock(lock);
2923         }
2924 }
2925 
2926 static inline void ext4_unlock_group(struct super_block *sb,
2927                                         ext4_group_t group)
2928 {
2929         spin_unlock(ext4_group_lock_ptr(sb, group));
2930 }
2931 
2932 /*
2933  * Block validity checking
2934  */
2935 #define ext4_check_indirect_blockref(inode, bh)                         \
2936         ext4_check_blockref(__func__, __LINE__, inode,                  \
2937                             (__le32 *)(bh)->b_data,                     \
2938                             EXT4_ADDR_PER_BLOCK((inode)->i_sb))
2939 
2940 #define ext4_ind_check_inode(inode)                                     \
2941         ext4_check_blockref(__func__, __LINE__, inode,                  \
2942                             EXT4_I(inode)->i_data,                      \
2943                             EXT4_NDIR_BLOCKS)
2944 
2945 /*
2946  * Inodes and files operations
2947  */
2948 
2949 /* dir.c */
2950 extern const struct file_operations ext4_dir_operations;
2951 
2952 /* file.c */
2953 extern const struct inode_operations ext4_file_inode_operations;
2954 extern const struct file_operations ext4_file_operations;
2955 extern loff_t ext4_llseek(struct file *file, loff_t offset, int origin);
2956 
2957 /* inline.c */
2958 extern int ext4_get_max_inline_size(struct inode *inode);
2959 extern int ext4_find_inline_data_nolock(struct inode *inode);
2960 extern int ext4_init_inline_data(handle_t *handle, struct inode *inode,
2961                                  unsigned int len);
2962 extern int ext4_destroy_inline_data(handle_t *handle, struct inode *inode);
2963 
2964 extern int ext4_readpage_inline(struct inode *inode, struct page *page);
2965 extern int ext4_try_to_write_inline_data(struct address_space *mapping,
2966                                          struct inode *inode,
2967                                          loff_t pos, unsigned len,
2968                                          unsigned flags,
2969                                          struct page **pagep);
2970 extern int ext4_write_inline_data_end(struct inode *inode,
2971                                       loff_t pos, unsigned len,
2972                                       unsigned copied,
2973                                       struct page *page);
2974 extern struct buffer_head *
2975 ext4_journalled_write_inline_data(struct inode *inode,
2976                                   unsigned len,
2977                                   struct page *page);
2978 extern int ext4_da_write_inline_data_begin(struct address_space *mapping,
2979                                            struct inode *inode,
2980                                            loff_t pos, unsigned len,
2981                                            unsigned flags,
2982                                            struct page **pagep,
2983                                            void **fsdata);
2984 extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
2985                                          unsigned len, unsigned copied,
2986                                          struct page *page);
2987 extern int ext4_try_add_inline_entry(handle_t *handle,
2988                                      struct ext4_filename *fname,
2989                                      struct dentry *dentry,
2990                                      struct inode *inode);
2991 extern int ext4_try_create_inline_dir(handle_t *handle,
2992                                       struct inode *parent,
2993                                       struct inode *inode);
2994 extern int ext4_read_inline_dir(struct file *filp,
2995                                 struct dir_context *ctx,
2996                                 int *has_inline_data);
2997 extern int htree_inlinedir_to_tree(struct file *dir_file,
2998                                    struct inode *dir, ext4_lblk_t block,
2999                                    struct dx_hash_info *hinfo,
3000                                    __u32 start_hash, __u32 start_minor_hash,
3001                                    int *has_inline_data);
3002 extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
3003                                         struct ext4_filename *fname,
3004                                         const struct qstr *d_name,
3005                                         struct ext4_dir_entry_2 **res_dir,
3006                                         int *has_inline_data);
3007 extern int ext4_delete_inline_entry(handle_t *handle,
3008                                     struct inode *dir,
3009                                     struct ext4_dir_entry_2 *de_del,
3010                                     struct buffer_head *bh,
3011                                     int *has_inline_data);
3012 extern int empty_inline_dir(struct inode *dir, int *has_inline_data);
3013 extern struct buffer_head *ext4_get_first_inline_block(struct inode *inode,
3014                                         struct ext4_dir_entry_2 **parent_de,
3015                                         int *retval);
3016 extern int ext4_inline_data_fiemap(struct inode *inode,
3017                                    struct fiemap_extent_info *fieinfo,
3018                                    int *has_inline, __u64 start, __u64 len);
3019 extern int ext4_try_to_evict_inline_data(handle_t *handle,
3020                                          struct inode *inode,
3021                                          int needed);
3022 extern void ext4_inline_data_truncate(struct inode *inode, int *has_inline);
3023 
3024 extern int ext4_convert_inline_data(struct inode *inode);
3025 
3026 static inline int ext4_has_inline_data(struct inode *inode)
3027 {
3028         return ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA) &&
3029                EXT4_I(inode)->i_inline_off;
3030 }
3031 
3032 /* namei.c */
3033 extern const struct inode_operations ext4_dir_inode_operations;
3034 extern const struct inode_operations ext4_special_inode_operations;
3035 extern struct dentry *ext4_get_parent(struct dentry *child);
3036 extern struct ext4_dir_entry_2 *ext4_init_dot_dotdot(struct inode *inode,
3037                                  struct ext4_dir_entry_2 *de,
3038                                  int blocksize, int csum_size,
3039                                  unsigned int parent_ino, int dotdot_real_len);
3040 extern void initialize_dirent_tail(struct ext4_dir_entry_tail *t,
3041                                    unsigned int blocksize);
3042 extern int ext4_handle_dirty_dirent_node(handle_t *handle,
3043                                          struct inode *inode,
3044                                          struct buffer_head *bh);
3045 #define S_SHIFT 12
3046 static unsigned char ext4_type_by_mode[S_IFMT >> S_SHIFT] = {
3047         [S_IFREG >> S_SHIFT]    = EXT4_FT_REG_FILE,
3048         [S_IFDIR >> S_SHIFT]    = EXT4_FT_DIR,
3049         [S_IFCHR >> S_SHIFT]    = EXT4_FT_CHRDEV,
3050         [S_IFBLK >> S_SHIFT]    = EXT4_FT_BLKDEV,
3051         [S_IFIFO >> S_SHIFT]    = EXT4_FT_FIFO,
3052         [S_IFSOCK >> S_SHIFT]   = EXT4_FT_SOCK,
3053         [S_IFLNK >> S_SHIFT]    = EXT4_FT_SYMLINK,
3054 };
3055 
3056 static inline void ext4_set_de_type(struct super_block *sb,
3057                                 struct ext4_dir_entry_2 *de,
3058                                 umode_t mode) {
3059         if (ext4_has_feature_filetype(sb))
3060                 de->file_type = ext4_type_by_mode[(mode & S_IFMT)>>S_SHIFT];
3061 }
3062 
3063 /* readpages.c */
3064 extern int ext4_mpage_readpages(struct address_space *mapping,
3065                                 struct list_head *pages, struct page *page,
3066                                 unsigned nr_pages);
3067 
3068 /* symlink.c */
3069 extern const struct inode_operations ext4_encrypted_symlink_inode_operations;
3070 extern const struct inode_operations ext4_symlink_inode_operations;
3071 extern const struct inode_operations ext4_fast_symlink_inode_operations;
3072 
3073 /* sysfs.c */
3074 extern int ext4_register_sysfs(struct super_block *sb);
3075 extern void ext4_unregister_sysfs(struct super_block *sb);
3076 extern int __init ext4_init_sysfs(void);
3077 extern void ext4_exit_sysfs(void);
3078 
3079 /* block_validity */
3080 extern void ext4_release_system_zone(struct super_block *sb);
3081 extern int ext4_setup_system_zone(struct super_block *sb);
3082 extern int __init ext4_init_system_zone(void);
3083 extern void ext4_exit_system_zone(void);
3084 extern int ext4_data_block_valid(struct ext4_sb_info *sbi,
3085                                  ext4_fsblk_t start_blk,
3086                                  unsigned int count);
3087 extern int ext4_check_blockref(const char *, unsigned int,
3088                                struct inode *, __le32 *, unsigned int);
3089 
3090 /* extents.c */
3091 struct ext4_ext_path;
3092 struct ext4_extent;
3093 
3094 /*
3095  * Maximum number of logical blocks in a file; ext4_extent's ee_block is
3096  * __le32.
3097  */
3098 #define EXT_MAX_BLOCKS  0xffffffff
3099 
3100 extern int ext4_ext_tree_init(handle_t *handle, struct inode *);
3101 extern int ext4_ext_writepage_trans_blocks(struct inode *, int);
3102 extern int ext4_ext_index_trans_blocks(struct inode *inode, int extents);
3103 extern int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
3104                                struct ext4_map_blocks *map, int flags);
3105 extern void ext4_ext_truncate(handle_t *, struct inode *);
3106 extern int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
3107                                  ext4_lblk_t end);
3108 extern void ext4_ext_init(struct super_block *);
3109 extern void ext4_ext_release(struct super_block *);
3110 extern long ext4_fallocate(struct file *file, int mode, loff_t offset,
3111                           loff_t len);
3112 extern int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
3113                                           loff_t offset, ssize_t len);
3114 extern int ext4_map_blocks(handle_t *handle, struct inode *inode,
3115                            struct ext4_map_blocks *map, int flags);
3116 extern int ext4_ext_calc_metadata_amount(struct inode *inode,
3117                                          ext4_lblk_t lblocks);
3118 extern int ext4_ext_calc_credits_for_single_extent(struct inode *inode,
3119                                                    int num,
3120                                                    struct ext4_ext_path *path);
3121 extern int ext4_can_extents_be_merged(struct inode *inode,
3122                                       struct ext4_extent *ex1,
3123                                       struct ext4_extent *ex2);
3124 extern int ext4_ext_insert_extent(handle_t *, struct inode *,
3125                                   struct ext4_ext_path **,
3126                                   struct ext4_extent *, int);
3127 extern struct ext4_ext_path *ext4_find_extent(struct inode *, ext4_lblk_t,
3128                                               struct ext4_ext_path **,
3129                                               int flags);
3130 extern void ext4_ext_drop_refs(struct ext4_ext_path *);
3131 extern int ext4_ext_check_inode(struct inode *inode);
3132 extern int ext4_find_delalloc_range(struct inode *inode,
3133                                     ext4_lblk_t lblk_start,
3134                                     ext4_lblk_t lblk_end);
3135 extern int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk);
3136 extern ext4_lblk_t ext4_ext_next_allocated_block(struct ext4_ext_path *path);
3137 extern int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
3138                         __u64 start, __u64 len);
3139 extern int ext4_ext_precache(struct inode *inode);
3140 extern int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len);
3141 extern int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len);
3142 extern int ext4_swap_extents(handle_t *handle, struct inode *inode1,
3143                                 struct inode *inode2, ext4_lblk_t lblk1,
3144                              ext4_lblk_t lblk2,  ext4_lblk_t count,
3145                              int mark_unwritten,int *err);
3146 
3147 /* move_extent.c */
3148 extern void ext4_double_down_write_data_sem(struct inode *first,
3149                                             struct inode *second);
3150 extern void ext4_double_up_write_data_sem(struct inode *orig_inode,
3151                                           struct inode *donor_inode);
3152 extern int ext4_move_extents(struct file *o_filp, struct file *d_filp,
3153                              __u64 start_orig, __u64 start_donor,
3154                              __u64 len, __u64 *moved_len);
3155 
3156 /* page-io.c */
3157 extern int __init ext4_init_pageio(void);
3158 extern void ext4_exit_pageio(void);
3159 extern ext4_io_end_t *ext4_init_io_end(struct inode *inode, gfp_t flags);
3160 extern ext4_io_end_t *ext4_get_io_end(ext4_io_end_t *io_end);
3161 extern int ext4_put_io_end(ext4_io_end_t *io_end);
3162 extern void ext4_put_io_end_defer(ext4_io_end_t *io_end);
3163 extern void ext4_io_submit_init(struct ext4_io_submit *io,
3164                                 struct writeback_control *wbc);
3165 extern void ext4_end_io_rsv_work(struct work_struct *work);
3166 extern void ext4_io_submit(struct ext4_io_submit *io);
3167 extern int ext4_bio_write_page(struct ext4_io_submit *io,
3168                                struct page *page,
3169                                int len,
3170                                struct writeback_control *wbc,
3171                                bool keep_towrite);
3172 
3173 /* mmp.c */
3174 extern int ext4_multi_mount_protect(struct super_block *, ext4_fsblk_t);
3175 
3176 /*
3177  * Add new method to test whether block and inode bitmaps are properly
3178  * initialized. With uninit_bg reading the block from disk is not enough
3179  * to mark the bitmap uptodate. We need to also zero-out the bitmap
3180  */
3181 #define BH_BITMAP_UPTODATE BH_JBDPrivateStart
3182 
3183 static inline int bitmap_uptodate(struct buffer_head *bh)
3184 {
3185         return (buffer_uptodate(bh) &&
3186                         test_bit(BH_BITMAP_UPTODATE, &(bh)->b_state));
3187 }
3188 static inline void set_bitmap_uptodate(struct buffer_head *bh)
3189 {
3190         set_bit(BH_BITMAP_UPTODATE, &(bh)->b_state);
3191 }
3192 
3193 /*
3194  * Disable DIO read nolock optimization, so new dioreaders will be forced
3195  * to grab i_mutex
3196  */
3197 static inline void ext4_inode_block_unlocked_dio(struct inode *inode)
3198 {
3199         ext4_set_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
3200         smp_mb();
3201 }
3202 static inline void ext4_inode_resume_unlocked_dio(struct inode *inode)
3203 {
3204         smp_mb();
3205         ext4_clear_inode_state(inode, EXT4_STATE_DIOREAD_LOCK);
3206 }
3207 
3208 #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
3209 
3210 /* For ioend & aio unwritten conversion wait queues */
3211 #define EXT4_WQ_HASH_SZ         37
3212 #define ext4_ioend_wq(v)   (&ext4__ioend_wq[((unsigned long)(v)) %\
3213                                             EXT4_WQ_HASH_SZ])
3214 #define ext4_aio_mutex(v)  (&ext4__aio_mutex[((unsigned long)(v)) %\
3215                                              EXT4_WQ_HASH_SZ])
3216 extern wait_queue_head_t ext4__ioend_wq[EXT4_WQ_HASH_SZ];
3217 extern struct mutex ext4__aio_mutex[EXT4_WQ_HASH_SZ];
3218 
3219 #define EXT4_RESIZING   0
3220 extern int ext4_resize_begin(struct super_block *sb);
3221 extern void ext4_resize_end(struct super_block *sb);
3222 
3223 #endif  /* __KERNEL__ */
3224 
3225 #define EFSBADCRC       EBADMSG         /* Bad CRC detected */
3226 #define EFSCORRUPTED    EUCLEAN         /* Filesystem is corrupted */
3227 
3228 #endif  /* _EXT4_H */
3229 

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