Version:  2.0.40 2.2.26 2.4.37 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0

Linux/fs/nfs/nfs4super.c

  1 /*
  2  * Copyright (c) 2012 Bryan Schumaker <bjschuma@netapp.com>
  3  */
  4 #include <linux/init.h>
  5 #include <linux/module.h>
  6 #include <linux/nfs_idmap.h>
  7 #include <linux/nfs4_mount.h>
  8 #include <linux/nfs_fs.h>
  9 #include "delegation.h"
 10 #include "internal.h"
 11 #include "nfs4_fs.h"
 12 #include "dns_resolve.h"
 13 #include "pnfs.h"
 14 #include "nfs.h"
 15 
 16 #define NFSDBG_FACILITY         NFSDBG_VFS
 17 
 18 static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc);
 19 static void nfs4_evict_inode(struct inode *inode);
 20 static struct dentry *nfs4_remote_mount(struct file_system_type *fs_type,
 21         int flags, const char *dev_name, void *raw_data);
 22 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
 23         int flags, const char *dev_name, void *raw_data);
 24 static struct dentry *nfs4_remote_referral_mount(struct file_system_type *fs_type,
 25         int flags, const char *dev_name, void *raw_data);
 26 
 27 static struct file_system_type nfs4_remote_fs_type = {
 28         .owner          = THIS_MODULE,
 29         .name           = "nfs4",
 30         .mount          = nfs4_remote_mount,
 31         .kill_sb        = nfs_kill_super,
 32         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 33 };
 34 
 35 static struct file_system_type nfs4_remote_referral_fs_type = {
 36         .owner          = THIS_MODULE,
 37         .name           = "nfs4",
 38         .mount          = nfs4_remote_referral_mount,
 39         .kill_sb        = nfs_kill_super,
 40         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 41 };
 42 
 43 struct file_system_type nfs4_referral_fs_type = {
 44         .owner          = THIS_MODULE,
 45         .name           = "nfs4",
 46         .mount          = nfs4_referral_mount,
 47         .kill_sb        = nfs_kill_super,
 48         .fs_flags       = FS_RENAME_DOES_D_MOVE|FS_BINARY_MOUNTDATA,
 49 };
 50 
 51 static const struct super_operations nfs4_sops = {
 52         .alloc_inode    = nfs_alloc_inode,
 53         .destroy_inode  = nfs_destroy_inode,
 54         .write_inode    = nfs4_write_inode,
 55         .drop_inode     = nfs_drop_inode,
 56         .statfs         = nfs_statfs,
 57         .evict_inode    = nfs4_evict_inode,
 58         .umount_begin   = nfs_umount_begin,
 59         .show_options   = nfs_show_options,
 60         .show_devname   = nfs_show_devname,
 61         .show_path      = nfs_show_path,
 62         .show_stats     = nfs_show_stats,
 63         .remount_fs     = nfs_remount,
 64 };
 65 
 66 struct nfs_subversion nfs_v4 = {
 67         .owner = THIS_MODULE,
 68         .nfs_fs   = &nfs4_fs_type,
 69         .rpc_vers = &nfs_version4,
 70         .rpc_ops  = &nfs_v4_clientops,
 71         .sops     = &nfs4_sops,
 72         .xattr    = nfs4_xattr_handlers,
 73 };
 74 
 75 static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc)
 76 {
 77         int ret = nfs_write_inode(inode, wbc);
 78 
 79         if (ret == 0)
 80                 ret = pnfs_layoutcommit_inode(inode,
 81                                 wbc->sync_mode == WB_SYNC_ALL);
 82         return ret;
 83 }
 84 
 85 /*
 86  * Clean out any remaining NFSv4 state that might be left over due
 87  * to open() calls that passed nfs_atomic_lookup, but failed to call
 88  * nfs_open().
 89  */
 90 static void nfs4_evict_inode(struct inode *inode)
 91 {
 92         truncate_inode_pages_final(&inode->i_data);
 93         clear_inode(inode);
 94         pnfs_return_layout(inode);
 95         pnfs_destroy_layout(NFS_I(inode));
 96         /* If we are holding a delegation, return it! */
 97         nfs_inode_return_delegation_noreclaim(inode);
 98         /* First call standard NFS clear_inode() code */
 99         nfs_clear_inode(inode);
100 }
101 
102 /*
103  * Get the superblock for the NFS4 root partition
104  */
105 static struct dentry *
106 nfs4_remote_mount(struct file_system_type *fs_type, int flags,
107                   const char *dev_name, void *info)
108 {
109         struct nfs_mount_info *mount_info = info;
110         struct nfs_server *server;
111         struct dentry *mntroot = ERR_PTR(-ENOMEM);
112 
113         mount_info->set_security = nfs_set_sb_security;
114 
115         /* Get a volume representation */
116         server = nfs4_create_server(mount_info, &nfs_v4);
117         if (IS_ERR(server)) {
118                 mntroot = ERR_CAST(server);
119                 goto out;
120         }
121 
122         mntroot = nfs_fs_mount_common(server, flags, dev_name, mount_info, &nfs_v4);
123 
124 out:
125         return mntroot;
126 }
127 
128 static struct vfsmount *nfs_do_root_mount(struct file_system_type *fs_type,
129                 int flags, void *data, const char *hostname)
130 {
131         struct vfsmount *root_mnt;
132         char *root_devname;
133         size_t len;
134 
135         len = strlen(hostname) + 5;
136         root_devname = kmalloc(len, GFP_KERNEL);
137         if (root_devname == NULL)
138                 return ERR_PTR(-ENOMEM);
139         /* Does hostname needs to be enclosed in brackets? */
140         if (strchr(hostname, ':'))
141                 snprintf(root_devname, len, "[%s]:/", hostname);
142         else
143                 snprintf(root_devname, len, "%s:/", hostname);
144         root_mnt = vfs_kern_mount(fs_type, flags, root_devname, data);
145         kfree(root_devname);
146         return root_mnt;
147 }
148 
149 struct nfs_referral_count {
150         struct list_head list;
151         const struct task_struct *task;
152         unsigned int referral_count;
153 };
154 
155 static LIST_HEAD(nfs_referral_count_list);
156 static DEFINE_SPINLOCK(nfs_referral_count_list_lock);
157 
158 static struct nfs_referral_count *nfs_find_referral_count(void)
159 {
160         struct nfs_referral_count *p;
161 
162         list_for_each_entry(p, &nfs_referral_count_list, list) {
163                 if (p->task == current)
164                         return p;
165         }
166         return NULL;
167 }
168 
169 #define NFS_MAX_NESTED_REFERRALS 2
170 
171 static int nfs_referral_loop_protect(void)
172 {
173         struct nfs_referral_count *p, *new;
174         int ret = -ENOMEM;
175 
176         new = kmalloc(sizeof(*new), GFP_KERNEL);
177         if (!new)
178                 goto out;
179         new->task = current;
180         new->referral_count = 1;
181 
182         ret = 0;
183         spin_lock(&nfs_referral_count_list_lock);
184         p = nfs_find_referral_count();
185         if (p != NULL) {
186                 if (p->referral_count >= NFS_MAX_NESTED_REFERRALS)
187                         ret = -ELOOP;
188                 else
189                         p->referral_count++;
190         } else {
191                 list_add(&new->list, &nfs_referral_count_list);
192                 new = NULL;
193         }
194         spin_unlock(&nfs_referral_count_list_lock);
195         kfree(new);
196 out:
197         return ret;
198 }
199 
200 static void nfs_referral_loop_unprotect(void)
201 {
202         struct nfs_referral_count *p;
203 
204         spin_lock(&nfs_referral_count_list_lock);
205         p = nfs_find_referral_count();
206         p->referral_count--;
207         if (p->referral_count == 0)
208                 list_del(&p->list);
209         else
210                 p = NULL;
211         spin_unlock(&nfs_referral_count_list_lock);
212         kfree(p);
213 }
214 
215 static struct dentry *nfs_follow_remote_path(struct vfsmount *root_mnt,
216                 const char *export_path)
217 {
218         struct dentry *dentry;
219         int err;
220 
221         if (IS_ERR(root_mnt))
222                 return ERR_CAST(root_mnt);
223 
224         err = nfs_referral_loop_protect();
225         if (err) {
226                 mntput(root_mnt);
227                 return ERR_PTR(err);
228         }
229 
230         dentry = mount_subtree(root_mnt, export_path);
231         nfs_referral_loop_unprotect();
232 
233         return dentry;
234 }
235 
236 struct dentry *nfs4_try_mount(int flags, const char *dev_name,
237                               struct nfs_mount_info *mount_info,
238                               struct nfs_subversion *nfs_mod)
239 {
240         char *export_path;
241         struct vfsmount *root_mnt;
242         struct dentry *res;
243         struct nfs_parsed_mount_data *data = mount_info->parsed;
244 
245         dfprintk(MOUNT, "--> nfs4_try_mount()\n");
246 
247         export_path = data->nfs_server.export_path;
248         data->nfs_server.export_path = "/";
249         root_mnt = nfs_do_root_mount(&nfs4_remote_fs_type, flags, mount_info,
250                         data->nfs_server.hostname);
251         data->nfs_server.export_path = export_path;
252 
253         res = nfs_follow_remote_path(root_mnt, export_path);
254 
255         dfprintk(MOUNT, "<-- nfs4_try_mount() = %d%s\n",
256                  PTR_ERR_OR_ZERO(res),
257                  IS_ERR(res) ? " [error]" : "");
258         return res;
259 }
260 
261 static struct dentry *
262 nfs4_remote_referral_mount(struct file_system_type *fs_type, int flags,
263                            const char *dev_name, void *raw_data)
264 {
265         struct nfs_mount_info mount_info = {
266                 .fill_super = nfs_fill_super,
267                 .set_security = nfs_clone_sb_security,
268                 .cloned = raw_data,
269         };
270         struct nfs_server *server;
271         struct dentry *mntroot = ERR_PTR(-ENOMEM);
272 
273         dprintk("--> nfs4_referral_get_sb()\n");
274 
275         mount_info.mntfh = nfs_alloc_fhandle();
276         if (mount_info.cloned == NULL || mount_info.mntfh == NULL)
277                 goto out;
278 
279         /* create a new volume representation */
280         server = nfs4_create_referral_server(mount_info.cloned, mount_info.mntfh);
281         if (IS_ERR(server)) {
282                 mntroot = ERR_CAST(server);
283                 goto out;
284         }
285 
286         mntroot = nfs_fs_mount_common(server, flags, dev_name, &mount_info, &nfs_v4);
287 out:
288         nfs_free_fhandle(mount_info.mntfh);
289         return mntroot;
290 }
291 
292 /*
293  * Create an NFS4 server record on referral traversal
294  */
295 static struct dentry *nfs4_referral_mount(struct file_system_type *fs_type,
296                 int flags, const char *dev_name, void *raw_data)
297 {
298         struct nfs_clone_mount *data = raw_data;
299         char *export_path;
300         struct vfsmount *root_mnt;
301         struct dentry *res;
302 
303         dprintk("--> nfs4_referral_mount()\n");
304 
305         export_path = data->mnt_path;
306         data->mnt_path = "/";
307 
308         root_mnt = nfs_do_root_mount(&nfs4_remote_referral_fs_type,
309                         flags, data, data->hostname);
310         data->mnt_path = export_path;
311 
312         res = nfs_follow_remote_path(root_mnt, export_path);
313         dprintk("<-- nfs4_referral_mount() = %d%s\n",
314                 PTR_ERR_OR_ZERO(res),
315                 IS_ERR(res) ? " [error]" : "");
316         return res;
317 }
318 
319 
320 static int __init init_nfs_v4(void)
321 {
322         int err;
323 
324         err = nfs_dns_resolver_init();
325         if (err)
326                 goto out;
327 
328         err = nfs_idmap_init();
329         if (err)
330                 goto out1;
331 
332         err = nfs4_register_sysctl();
333         if (err)
334                 goto out2;
335 
336         register_nfs_version(&nfs_v4);
337         return 0;
338 out2:
339         nfs_idmap_quit();
340 out1:
341         nfs_dns_resolver_destroy();
342 out:
343         return err;
344 }
345 
346 static void __exit exit_nfs_v4(void)
347 {
348         /* Not called in the _init(), conditionally loaded */
349         nfs4_pnfs_v3_ds_connect_unload();
350 
351         unregister_nfs_version(&nfs_v4);
352         nfs4_unregister_sysctl();
353         nfs_idmap_quit();
354         nfs_dns_resolver_destroy();
355 }
356 
357 MODULE_LICENSE("GPL");
358 
359 module_init(init_nfs_v4);
360 module_exit(exit_nfs_v4);
361 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us