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1 /* 1 /*
2 * linux/fs/super.c 2 * linux/fs/super.c
3 * 3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds 4 * Copyright (C) 1991, 1992 Linus Torvalds
5 * 5 *
6 * super.c contains code to handle: - mount s 6 * super.c contains code to handle: - mount structures
7 * - super-b 7 * - super-block tables
8 * - filesys 8 * - filesystem drivers list
9 * - mount s 9 * - mount system call
10 * - umount 10 * - umount system call
11 * - ustat s 11 * - ustat system call
12 * 12 *
13 * GK 2/5/95 - Changed to support mounting t 13 * GK 2/5/95 - Changed to support mounting the root fs via NFS
14 * 14 *
15 * Added kerneld support: Jacques Gelinas and 15 * Added kerneld support: Jacques Gelinas and Bjorn Ekwall
16 * Added change_root: Werner Almesberger & Ha 16 * Added change_root: Werner Almesberger & Hans Lermen, Feb '96
17 * Added options to /proc/mounts: 17 * Added options to /proc/mounts:
18 * Torbjörn Lindh (torbjorn.lindh@gopta.se 18 * Torbjörn Lindh (torbjorn.lindh@gopta.se), April 14, 1996.
19 * Added devfs support: Richard Gooch <rgooch 19 * Added devfs support: Richard Gooch <rgooch@atnf.csiro.au>, 13-JAN-1998
20 * Heavily rewritten for 'one fs - one tree' 20 * Heavily rewritten for 'one fs - one tree' dcache architecture. AV, Mar 2000
21 */ 21 */
22 22
23 #include <linux/module.h> 23 #include <linux/module.h>
24 #include <linux/slab.h> 24 #include <linux/slab.h>
25 #include <linux/init.h> 25 #include <linux/init.h>
26 #include <linux/smp_lock.h> 26 #include <linux/smp_lock.h>
27 #include <linux/acct.h> 27 #include <linux/acct.h>
28 #include <linux/blkdev.h> 28 #include <linux/blkdev.h>
29 #include <linux/quotaops.h> 29 #include <linux/quotaops.h>
30 #include <linux/namei.h> 30 #include <linux/namei.h>
>> 31 #include <linux/buffer_head.h> /* for fsync_super() */
31 #include <linux/mount.h> 32 #include <linux/mount.h>
32 #include <linux/security.h> 33 #include <linux/security.h>
33 #include <linux/syscalls.h> 34 #include <linux/syscalls.h>
34 #include <linux/vfs.h> 35 #include <linux/vfs.h>
35 #include <linux/writeback.h> /* for 36 #include <linux/writeback.h> /* for the emergency remount stuff */
36 #include <linux/idr.h> 37 #include <linux/idr.h>
37 #include <linux/kobject.h> 38 #include <linux/kobject.h>
38 #include <linux/mutex.h> 39 #include <linux/mutex.h>
39 #include <linux/file.h> <<
40 #include <asm/uaccess.h> 40 #include <asm/uaccess.h>
41 #include "internal.h" <<
42 41
43 42
44 LIST_HEAD(super_blocks); 43 LIST_HEAD(super_blocks);
45 DEFINE_SPINLOCK(sb_lock); 44 DEFINE_SPINLOCK(sb_lock);
46 45
47 /** 46 /**
48 * alloc_super - create new sup 47 * alloc_super - create new superblock
49 * @type: filesystem type superblock sho 48 * @type: filesystem type superblock should belong to
50 * 49 *
51 * Allocates and initializes a new &struc 50 * Allocates and initializes a new &struct super_block. alloc_super()
52 * returns a pointer new superblock or %N 51 * returns a pointer new superblock or %NULL if allocation had failed.
53 */ 52 */
54 static struct super_block *alloc_super(struct 53 static struct super_block *alloc_super(struct file_system_type *type)
55 { 54 {
56 struct super_block *s = kzalloc(sizeof 55 struct super_block *s = kzalloc(sizeof(struct super_block), GFP_USER);
57 static struct super_operations default 56 static struct super_operations default_op;
58 57
59 if (s) { 58 if (s) {
60 if (security_sb_alloc(s)) { 59 if (security_sb_alloc(s)) {
61 kfree(s); 60 kfree(s);
62 s = NULL; 61 s = NULL;
63 goto out; 62 goto out;
64 } 63 }
65 INIT_LIST_HEAD(&s->s_dirty); 64 INIT_LIST_HEAD(&s->s_dirty);
66 INIT_LIST_HEAD(&s->s_io); 65 INIT_LIST_HEAD(&s->s_io);
67 INIT_LIST_HEAD(&s->s_more_io); 66 INIT_LIST_HEAD(&s->s_more_io);
68 INIT_LIST_HEAD(&s->s_files); !! 67 percpu_list_init(&s->s_files);
>> 68 init_qrcu_struct(&s->s_qrcu);
69 INIT_LIST_HEAD(&s->s_instances 69 INIT_LIST_HEAD(&s->s_instances);
70 INIT_HLIST_HEAD(&s->s_anon); 70 INIT_HLIST_HEAD(&s->s_anon);
71 INIT_LIST_HEAD(&s->s_inodes); 71 INIT_LIST_HEAD(&s->s_inodes);
72 INIT_LIST_HEAD(&s->s_dentry_lr <<
73 init_rwsem(&s->s_umount); 72 init_rwsem(&s->s_umount);
74 mutex_init(&s->s_lock); 73 mutex_init(&s->s_lock);
75 lockdep_set_class(&s->s_umount 74 lockdep_set_class(&s->s_umount, &type->s_umount_key);
76 /* 75 /*
77 * The locking rules for s_loc 76 * The locking rules for s_lock are up to the
78 * filesystem. For example ext 77 * filesystem. For example ext3fs has different
79 * lock ordering than usbfs: 78 * lock ordering than usbfs:
80 */ 79 */
81 lockdep_set_class(&s->s_lock, 80 lockdep_set_class(&s->s_lock, &type->s_lock_key);
82 /* !! 81 down_write(&s->s_umount);
83 * sget() can have s_umount re <<
84 * <<
85 * When it cannot find a suita <<
86 * one (this one), and tries a <<
87 * one. <<
88 * <<
89 * In case that succeeds, it w <<
90 * lock of the old one. Since <<
91 * locks, and this object isn' <<
92 * risk of deadlocks. <<
93 * <<
94 * Annotate this by putting th <<
95 * subclass. <<
96 */ <<
97 down_write_nested(&s->s_umount <<
98 s->s_count = S_BIAS; 82 s->s_count = S_BIAS;
99 atomic_set(&s->s_active, 1); 83 atomic_set(&s->s_active, 1);
100 mutex_init(&s->s_vfs_rename_mu 84 mutex_init(&s->s_vfs_rename_mutex);
101 mutex_init(&s->s_dquot.dqio_mu 85 mutex_init(&s->s_dquot.dqio_mutex);
102 mutex_init(&s->s_dquot.dqonoff 86 mutex_init(&s->s_dquot.dqonoff_mutex);
103 init_rwsem(&s->s_dquot.dqptr_s 87 init_rwsem(&s->s_dquot.dqptr_sem);
104 init_waitqueue_head(&s->s_wait 88 init_waitqueue_head(&s->s_wait_unfrozen);
105 s->s_maxbytes = MAX_NON_LFS; 89 s->s_maxbytes = MAX_NON_LFS;
106 s->dq_op = sb_dquot_ops; 90 s->dq_op = sb_dquot_ops;
107 s->s_qcop = sb_quotactl_ops; 91 s->s_qcop = sb_quotactl_ops;
108 s->s_op = &default_op; 92 s->s_op = &default_op;
109 s->s_time_gran = 1000000000; 93 s->s_time_gran = 1000000000;
110 } 94 }
111 out: 95 out:
112 return s; 96 return s;
113 } 97 }
114 98
115 /** 99 /**
116 * destroy_super - frees a superb 100 * destroy_super - frees a superblock
117 * @s: superblock to free 101 * @s: superblock to free
118 * 102 *
119 * Frees a superblock. 103 * Frees a superblock.
120 */ 104 */
121 static inline void destroy_super(struct super_ 105 static inline void destroy_super(struct super_block *s)
122 { 106 {
>> 107 percpu_list_destroy(&s->s_files);
123 security_sb_free(s); 108 security_sb_free(s);
124 kfree(s->s_subtype); 109 kfree(s->s_subtype);
125 kfree(s->s_options); 110 kfree(s->s_options);
126 kfree(s); 111 kfree(s);
127 } 112 }
128 113
129 /* Superblock refcounting */ 114 /* Superblock refcounting */
130 115
131 /* 116 /*
132 * Drop a superblock's refcount. Returns non- 117 * Drop a superblock's refcount. Returns non-zero if the superblock was
133 * destroyed. The caller must hold sb_lock. 118 * destroyed. The caller must hold sb_lock.
134 */ 119 */
135 static int __put_super(struct super_block *sb) !! 120 int __put_super(struct super_block *sb)
136 { 121 {
137 int ret = 0; 122 int ret = 0;
138 123
139 if (!--sb->s_count) { 124 if (!--sb->s_count) {
140 destroy_super(sb); 125 destroy_super(sb);
141 ret = 1; 126 ret = 1;
142 } 127 }
143 return ret; 128 return ret;
144 } 129 }
145 130
146 /* 131 /*
147 * Drop a superblock's refcount. 132 * Drop a superblock's refcount.
148 * Returns non-zero if the superblock is about 133 * Returns non-zero if the superblock is about to be destroyed and
149 * at least is already removed from super_bloc 134 * at least is already removed from super_blocks list, so if we are
150 * making a loop through super blocks then we 135 * making a loop through super blocks then we need to restart.
151 * The caller must hold sb_lock. 136 * The caller must hold sb_lock.
152 */ 137 */
153 int __put_super_and_need_restart(struct super_ 138 int __put_super_and_need_restart(struct super_block *sb)
154 { 139 {
155 /* check for race with generic_shutdow 140 /* check for race with generic_shutdown_super() */
156 if (list_empty(&sb->s_list)) { 141 if (list_empty(&sb->s_list)) {
157 /* super block is removed, nee 142 /* super block is removed, need to restart... */
158 __put_super(sb); 143 __put_super(sb);
159 return 1; 144 return 1;
160 } 145 }
161 /* can't be the last, since s_list is 146 /* can't be the last, since s_list is still in use */
162 sb->s_count--; 147 sb->s_count--;
163 BUG_ON(sb->s_count == 0); 148 BUG_ON(sb->s_count == 0);
164 return 0; 149 return 0;
165 } 150 }
166 151
167 /** 152 /**
168 * put_super - drop a tempora 153 * put_super - drop a temporary reference to superblock
169 * @sb: superblock in question 154 * @sb: superblock in question
170 * 155 *
171 * Drops a temporary reference, frees sup 156 * Drops a temporary reference, frees superblock if there's no
172 * references left. 157 * references left.
173 */ 158 */
174 static void put_super(struct super_block *sb) 159 static void put_super(struct super_block *sb)
175 { 160 {
176 spin_lock(&sb_lock); 161 spin_lock(&sb_lock);
177 __put_super(sb); 162 __put_super(sb);
178 spin_unlock(&sb_lock); 163 spin_unlock(&sb_lock);
179 } 164 }
180 165
181 166
182 /** 167 /**
183 * deactivate_super - drop a 168 * deactivate_super - drop an active reference to superblock
184 * @s: superblock to deactivate 169 * @s: superblock to deactivate
185 * 170 *
186 * Drops an active reference to superbloc 171 * Drops an active reference to superblock, acquiring a temprory one if
187 * there is no active references left. I 172 * there is no active references left. In that case we lock superblock,
188 * tell fs driver to shut it down and dro 173 * tell fs driver to shut it down and drop the temporary reference we
189 * had just acquired. 174 * had just acquired.
190 */ 175 */
191 void deactivate_super(struct super_block *s) 176 void deactivate_super(struct super_block *s)
192 { 177 {
193 struct file_system_type *fs = s->s_typ 178 struct file_system_type *fs = s->s_type;
194 if (atomic_dec_and_lock(&s->s_active, 179 if (atomic_dec_and_lock(&s->s_active, &sb_lock)) {
195 s->s_count -= S_BIAS-1; 180 s->s_count -= S_BIAS-1;
196 spin_unlock(&sb_lock); 181 spin_unlock(&sb_lock);
197 vfs_dq_off(s, 0); !! 182 DQUOT_OFF(s);
198 down_write(&s->s_umount); 183 down_write(&s->s_umount);
199 fs->kill_sb(s); 184 fs->kill_sb(s);
200 put_filesystem(fs); 185 put_filesystem(fs);
201 put_super(s); 186 put_super(s);
202 } 187 }
203 } 188 }
204 189
205 EXPORT_SYMBOL(deactivate_super); 190 EXPORT_SYMBOL(deactivate_super);
206 191
207 /** 192 /**
208 * deactivate_locked_super - drop a <<
209 * @s: superblock to deactivate <<
210 * <<
211 * Equivalent of up_write(&s->s_umount); <<
212 * it does not unlock it until it's all o <<
213 * use to dispose of new superblock on -> <<
214 * will see the sucker until it's all ove <<
215 * deactivate_super is safe for that purp <<
216 * safe to use or has NULL ->s_root when <<
217 */ <<
218 void deactivate_locked_super(struct super_bloc <<
219 { <<
220 struct file_system_type *fs = s->s_typ <<
221 if (atomic_dec_and_lock(&s->s_active, <<
222 s->s_count -= S_BIAS-1; <<
223 spin_unlock(&sb_lock); <<
224 vfs_dq_off(s, 0); <<
225 fs->kill_sb(s); <<
226 put_filesystem(fs); <<
227 put_super(s); <<
228 } else { <<
229 up_write(&s->s_umount); <<
230 } <<
231 } <<
232 <<
233 EXPORT_SYMBOL(deactivate_locked_super); <<
234 <<
235 /** <<
236 * grab_super - acquire an active referen 193 * grab_super - acquire an active reference
237 * @s: reference we are trying to make ac 194 * @s: reference we are trying to make active
238 * 195 *
239 * Tries to acquire an active reference. 196 * Tries to acquire an active reference. grab_super() is used when we
240 * had just found a superblock in super_b 197 * had just found a superblock in super_blocks or fs_type->fs_supers
241 * and want to turn it into a full-blown 198 * and want to turn it into a full-blown active reference. grab_super()
242 * is called with sb_lock held and drops 199 * is called with sb_lock held and drops it. Returns 1 in case of
243 * success, 0 if we had failed (superbloc 200 * success, 0 if we had failed (superblock contents was already dead or
244 * dying when grab_super() had been calle 201 * dying when grab_super() had been called).
245 */ 202 */
246 static int grab_super(struct super_block *s) _ 203 static int grab_super(struct super_block *s) __releases(sb_lock)
247 { 204 {
248 s->s_count++; 205 s->s_count++;
249 spin_unlock(&sb_lock); 206 spin_unlock(&sb_lock);
250 down_write(&s->s_umount); 207 down_write(&s->s_umount);
251 if (s->s_root) { 208 if (s->s_root) {
252 spin_lock(&sb_lock); 209 spin_lock(&sb_lock);
253 if (s->s_count > S_BIAS) { 210 if (s->s_count > S_BIAS) {
254 atomic_inc(&s->s_activ 211 atomic_inc(&s->s_active);
255 s->s_count--; 212 s->s_count--;
256 spin_unlock(&sb_lock); 213 spin_unlock(&sb_lock);
257 return 1; 214 return 1;
258 } 215 }
259 spin_unlock(&sb_lock); 216 spin_unlock(&sb_lock);
260 } 217 }
261 up_write(&s->s_umount); 218 up_write(&s->s_umount);
262 put_super(s); 219 put_super(s);
263 yield(); 220 yield();
264 return 0; 221 return 0;
265 } 222 }
266 223
267 /* 224 /*
268 * Superblock locking. We really ought to get 225 * Superblock locking. We really ought to get rid of these two.
269 */ 226 */
270 void lock_super(struct super_block * sb) 227 void lock_super(struct super_block * sb)
271 { 228 {
272 get_fs_excl(); 229 get_fs_excl();
273 mutex_lock(&sb->s_lock); 230 mutex_lock(&sb->s_lock);
274 } 231 }
275 232
276 void unlock_super(struct super_block * sb) 233 void unlock_super(struct super_block * sb)
277 { 234 {
278 put_fs_excl(); 235 put_fs_excl();
279 mutex_unlock(&sb->s_lock); 236 mutex_unlock(&sb->s_lock);
280 } 237 }
281 238
282 EXPORT_SYMBOL(lock_super); 239 EXPORT_SYMBOL(lock_super);
283 EXPORT_SYMBOL(unlock_super); 240 EXPORT_SYMBOL(unlock_super);
284 241
>> 242 /*
>> 243 * Write out and wait upon all dirty data associated with this
>> 244 * superblock. Filesystem data as well as the underlying block
>> 245 * device. Takes the superblock lock. Requires a second blkdev
>> 246 * flush by the caller to complete the operation.
>> 247 */
>> 248 void __fsync_super(struct super_block *sb)
>> 249 {
>> 250 sync_inodes_sb(sb, 0);
>> 251 DQUOT_SYNC(sb);
>> 252 lock_super(sb);
>> 253 if (sb->s_dirt && sb->s_op->write_super)
>> 254 sb->s_op->write_super(sb);
>> 255 unlock_super(sb);
>> 256 if (sb->s_op->sync_fs)
>> 257 sb->s_op->sync_fs(sb, 1);
>> 258 sync_blockdev(sb->s_bdev);
>> 259 sync_inodes_sb(sb, 1);
>> 260 }
>> 261
>> 262 /*
>> 263 * Write out and wait upon all dirty data associated with this
>> 264 * superblock. Filesystem data as well as the underlying block
>> 265 * device. Takes the superblock lock.
>> 266 */
>> 267 int fsync_super(struct super_block *sb)
>> 268 {
>> 269 __fsync_super(sb);
>> 270 return sync_blockdev(sb->s_bdev);
>> 271 }
>> 272
285 /** 273 /**
286 * generic_shutdown_super - common 274 * generic_shutdown_super - common helper for ->kill_sb()
287 * @sb: superblock to kill 275 * @sb: superblock to kill
288 * 276 *
289 * generic_shutdown_super() does all fs-i 277 * generic_shutdown_super() does all fs-independent work on superblock
290 * shutdown. Typical ->kill_sb() should 278 * shutdown. Typical ->kill_sb() should pick all fs-specific objects
291 * that need destruction out of superbloc 279 * that need destruction out of superblock, call generic_shutdown_super()
292 * and release aforementioned objects. N 280 * and release aforementioned objects. Note: dentries and inodes _are_
293 * taken care of and do not need specific 281 * taken care of and do not need specific handling.
294 * 282 *
295 * Upon calling this function, the filesy 283 * Upon calling this function, the filesystem may no longer alter or
296 * rearrange the set of dentries belongin 284 * rearrange the set of dentries belonging to this super_block, nor may it
297 * change the attachments of dentries to 285 * change the attachments of dentries to inodes.
298 */ 286 */
299 void generic_shutdown_super(struct super_block 287 void generic_shutdown_super(struct super_block *sb)
300 { 288 {
301 const struct super_operations *sop = s 289 const struct super_operations *sop = sb->s_op;
302 290
303 <<
304 if (sb->s_root) { 291 if (sb->s_root) {
305 shrink_dcache_for_umount(sb); 292 shrink_dcache_for_umount(sb);
306 sync_filesystem(sb); !! 293 fsync_super(sb);
307 get_fs_excl(); !! 294 lock_super(sb);
308 sb->s_flags &= ~MS_ACTIVE; 295 sb->s_flags &= ~MS_ACTIVE;
309 <<
310 /* bad name - it should be evi 296 /* bad name - it should be evict_inodes() */
311 invalidate_inodes(sb); 297 invalidate_inodes(sb);
>> 298 lock_kernel();
312 299
>> 300 if (sop->write_super && sb->s_dirt)
>> 301 sop->write_super(sb);
313 if (sop->put_super) 302 if (sop->put_super)
314 sop->put_super(sb); 303 sop->put_super(sb);
315 304
316 /* Forget any remaining inodes 305 /* Forget any remaining inodes */
317 if (invalidate_inodes(sb)) { 306 if (invalidate_inodes(sb)) {
318 printk("VFS: Busy inod 307 printk("VFS: Busy inodes after unmount of %s. "
319 "Self-destruct in 5 308 "Self-destruct in 5 seconds. Have a nice day...\n",
320 sb->s_id); 309 sb->s_id);
321 } 310 }
322 put_fs_excl(); !! 311
>> 312 unlock_kernel();
>> 313 unlock_super(sb);
323 } 314 }
324 spin_lock(&sb_lock); 315 spin_lock(&sb_lock);
325 /* should be initialized for __put_sup 316 /* should be initialized for __put_super_and_need_restart() */
326 list_del_init(&sb->s_list); 317 list_del_init(&sb->s_list);
327 list_del(&sb->s_instances); 318 list_del(&sb->s_instances);
328 spin_unlock(&sb_lock); 319 spin_unlock(&sb_lock);
329 up_write(&sb->s_umount); 320 up_write(&sb->s_umount);
330 } 321 }
331 322
332 EXPORT_SYMBOL(generic_shutdown_super); 323 EXPORT_SYMBOL(generic_shutdown_super);
333 324
334 /** 325 /**
335 * sget - find or create a super 326 * sget - find or create a superblock
336 * @type: filesystem type superblock sho 327 * @type: filesystem type superblock should belong to
337 * @test: comparison callback 328 * @test: comparison callback
338 * @set: setup callback 329 * @set: setup callback
339 * @data: argument to each of them 330 * @data: argument to each of them
340 */ 331 */
341 struct super_block *sget(struct file_system_ty 332 struct super_block *sget(struct file_system_type *type,
342 int (*test)(struct sup 333 int (*test)(struct super_block *,void *),
343 int (*set)(struct supe 334 int (*set)(struct super_block *,void *),
344 void *data) 335 void *data)
345 { 336 {
346 struct super_block *s = NULL; 337 struct super_block *s = NULL;
347 struct super_block *old; 338 struct super_block *old;
348 int err; 339 int err;
349 340
350 retry: 341 retry:
351 spin_lock(&sb_lock); 342 spin_lock(&sb_lock);
352 if (test) { 343 if (test) {
353 list_for_each_entry(old, &type 344 list_for_each_entry(old, &type->fs_supers, s_instances) {
354 if (!test(old, data)) 345 if (!test(old, data))
355 continue; 346 continue;
356 if (!grab_super(old)) 347 if (!grab_super(old))
357 goto retry; 348 goto retry;
358 if (s) { !! 349 if (s)
359 up_write(&s->s <<
360 destroy_super( 350 destroy_super(s);
361 } <<
362 return old; 351 return old;
363 } 352 }
364 } 353 }
365 if (!s) { 354 if (!s) {
366 spin_unlock(&sb_lock); 355 spin_unlock(&sb_lock);
367 s = alloc_super(type); 356 s = alloc_super(type);
368 if (!s) 357 if (!s)
369 return ERR_PTR(-ENOMEM 358 return ERR_PTR(-ENOMEM);
370 goto retry; 359 goto retry;
371 } 360 }
372 361
373 err = set(s, data); 362 err = set(s, data);
374 if (err) { 363 if (err) {
375 spin_unlock(&sb_lock); 364 spin_unlock(&sb_lock);
376 up_write(&s->s_umount); <<
377 destroy_super(s); 365 destroy_super(s);
378 return ERR_PTR(err); 366 return ERR_PTR(err);
379 } 367 }
380 s->s_type = type; 368 s->s_type = type;
381 strlcpy(s->s_id, type->name, sizeof(s- 369 strlcpy(s->s_id, type->name, sizeof(s->s_id));
382 list_add_tail(&s->s_list, &super_block 370 list_add_tail(&s->s_list, &super_blocks);
383 list_add(&s->s_instances, &type->fs_su 371 list_add(&s->s_instances, &type->fs_supers);
384 spin_unlock(&sb_lock); 372 spin_unlock(&sb_lock);
385 get_filesystem(type); 373 get_filesystem(type);
386 return s; 374 return s;
387 } 375 }
388 376
389 EXPORT_SYMBOL(sget); 377 EXPORT_SYMBOL(sget);
390 378
391 void drop_super(struct super_block *sb) 379 void drop_super(struct super_block *sb)
392 { 380 {
393 up_read(&sb->s_umount); 381 up_read(&sb->s_umount);
394 put_super(sb); 382 put_super(sb);
395 } 383 }
396 384
397 EXPORT_SYMBOL(drop_super); 385 EXPORT_SYMBOL(drop_super);
398 386
399 /** !! 387 static inline void write_super(struct super_block *sb)
400 * sync_supers - helper for periodic superbloc !! 388 {
401 * !! 389 lock_super(sb);
402 * Call the write_super method if present on a !! 390 if (sb->s_root && sb->s_dirt)
403 * the system. This is for the periodic write !! 391 if (sb->s_op->write_super)
404 * filesystems. For data integrity superblock !! 392 sb->s_op->write_super(sb);
405 * sync_filesystems() instead. !! 393 unlock_super(sb);
406 * !! 394 }
>> 395
>> 396 /*
407 * Note: check the dirty flag before waiting, 397 * Note: check the dirty flag before waiting, so we don't
408 * hold up the sync while mounting a device. ( 398 * hold up the sync while mounting a device. (The newly
409 * mounted device won't need syncing.) 399 * mounted device won't need syncing.)
410 */ 400 */
411 void sync_supers(void) 401 void sync_supers(void)
412 { 402 {
413 struct super_block *sb; 403 struct super_block *sb;
414 404
415 spin_lock(&sb_lock); 405 spin_lock(&sb_lock);
416 restart: 406 restart:
417 list_for_each_entry(sb, &super_blocks, 407 list_for_each_entry(sb, &super_blocks, s_list) {
418 if (sb->s_op->write_super && s !! 408 if (sb->s_dirt) {
419 sb->s_count++; 409 sb->s_count++;
420 spin_unlock(&sb_lock); 410 spin_unlock(&sb_lock);
421 <<
422 down_read(&sb->s_umoun 411 down_read(&sb->s_umount);
423 if (sb->s_root && sb-> !! 412 write_super(sb);
424 sb->s_op->writ <<
425 up_read(&sb->s_umount) 413 up_read(&sb->s_umount);
426 <<
427 spin_lock(&sb_lock); 414 spin_lock(&sb_lock);
428 if (__put_super_and_ne 415 if (__put_super_and_need_restart(sb))
429 goto restart; 416 goto restart;
430 } 417 }
431 } 418 }
432 spin_unlock(&sb_lock); 419 spin_unlock(&sb_lock);
433 } 420 }
434 421
>> 422 /*
>> 423 * Call the ->sync_fs super_op against all filesystems which are r/w and
>> 424 * which implement it.
>> 425 *
>> 426 * This operation is careful to avoid the livelock which could easily happen
>> 427 * if two or more filesystems are being continuously dirtied. s_need_sync_fs
>> 428 * is used only here. We set it against all filesystems and then clear it as
>> 429 * we sync them. So redirtied filesystems are skipped.
>> 430 *
>> 431 * But if process A is currently running sync_filesystems and then process B
>> 432 * calls sync_filesystems as well, process B will set all the s_need_sync_fs
>> 433 * flags again, which will cause process A to resync everything. Fix that with
>> 434 * a local mutex.
>> 435 *
>> 436 * (Fabian) Avoid sync_fs with clean fs & wait mode 0
>> 437 */
>> 438 void sync_filesystems(int wait)
>> 439 {
>> 440 struct super_block *sb;
>> 441 static DEFINE_MUTEX(mutex);
>> 442
>> 443 mutex_lock(&mutex); /* Could be down_interruptible */
>> 444 spin_lock(&sb_lock);
>> 445 list_for_each_entry(sb, &super_blocks, s_list) {
>> 446 if (!sb->s_op->sync_fs)
>> 447 continue;
>> 448 if (sb->s_flags & MS_RDONLY)
>> 449 continue;
>> 450 sb->s_need_sync_fs = 1;
>> 451 }
>> 452
>> 453 restart:
>> 454 list_for_each_entry(sb, &super_blocks, s_list) {
>> 455 if (!sb->s_need_sync_fs)
>> 456 continue;
>> 457 sb->s_need_sync_fs = 0;
>> 458 if (sb->s_flags & MS_RDONLY)
>> 459 continue; /* hm. Was remounted r/o meanwhile */
>> 460 sb->s_count++;
>> 461 spin_unlock(&sb_lock);
>> 462 down_read(&sb->s_umount);
>> 463 if (sb->s_root && (wait || sb->s_dirt))
>> 464 sb->s_op->sync_fs(sb, wait);
>> 465 up_read(&sb->s_umount);
>> 466 /* restart only when sb is no longer on the list */
>> 467 spin_lock(&sb_lock);
>> 468 if (__put_super_and_need_restart(sb))
>> 469 goto restart;
>> 470 }
>> 471 spin_unlock(&sb_lock);
>> 472 mutex_unlock(&mutex);
>> 473 }
>> 474
435 /** 475 /**
436 * get_super - get the superblock of a de 476 * get_super - get the superblock of a device
437 * @bdev: device to get the superblock fo 477 * @bdev: device to get the superblock for
438 * 478 *
439 * Scans the superblock list and finds th 479 * Scans the superblock list and finds the superblock of the file system
440 * mounted on the device given. %NULL is 480 * mounted on the device given. %NULL is returned if no match is found.
441 */ 481 */
442 482
443 struct super_block * get_super(struct block_de 483 struct super_block * get_super(struct block_device *bdev)
444 { 484 {
445 struct super_block *sb; 485 struct super_block *sb;
446 486
447 if (!bdev) 487 if (!bdev)
448 return NULL; 488 return NULL;
449 489
450 spin_lock(&sb_lock); 490 spin_lock(&sb_lock);
451 rescan: 491 rescan:
452 list_for_each_entry(sb, &super_blocks, 492 list_for_each_entry(sb, &super_blocks, s_list) {
453 if (sb->s_bdev == bdev) { 493 if (sb->s_bdev == bdev) {
454 sb->s_count++; 494 sb->s_count++;
455 spin_unlock(&sb_lock); 495 spin_unlock(&sb_lock);
456 down_read(&sb->s_umoun 496 down_read(&sb->s_umount);
457 if (sb->s_root) 497 if (sb->s_root)
458 return sb; 498 return sb;
459 up_read(&sb->s_umount) 499 up_read(&sb->s_umount);
460 /* restart only when s 500 /* restart only when sb is no longer on the list */
461 spin_lock(&sb_lock); 501 spin_lock(&sb_lock);
462 if (__put_super_and_ne 502 if (__put_super_and_need_restart(sb))
463 goto rescan; 503 goto rescan;
464 } 504 }
465 } 505 }
466 spin_unlock(&sb_lock); 506 spin_unlock(&sb_lock);
467 return NULL; 507 return NULL;
468 } 508 }
469 509
470 EXPORT_SYMBOL(get_super); 510 EXPORT_SYMBOL(get_super);
471 511
472 struct super_block * user_get_super(dev_t dev) 512 struct super_block * user_get_super(dev_t dev)
473 { 513 {
474 struct super_block *sb; 514 struct super_block *sb;
475 515
476 spin_lock(&sb_lock); 516 spin_lock(&sb_lock);
477 rescan: 517 rescan:
478 list_for_each_entry(sb, &super_blocks, 518 list_for_each_entry(sb, &super_blocks, s_list) {
479 if (sb->s_dev == dev) { 519 if (sb->s_dev == dev) {
480 sb->s_count++; 520 sb->s_count++;
481 spin_unlock(&sb_lock); 521 spin_unlock(&sb_lock);
482 down_read(&sb->s_umoun 522 down_read(&sb->s_umount);
483 if (sb->s_root) 523 if (sb->s_root)
484 return sb; 524 return sb;
485 up_read(&sb->s_umount) 525 up_read(&sb->s_umount);
486 /* restart only when s 526 /* restart only when sb is no longer on the list */
487 spin_lock(&sb_lock); 527 spin_lock(&sb_lock);
488 if (__put_super_and_ne 528 if (__put_super_and_need_restart(sb))
489 goto rescan; 529 goto rescan;
490 } 530 }
491 } 531 }
492 spin_unlock(&sb_lock); 532 spin_unlock(&sb_lock);
493 return NULL; 533 return NULL;
494 } 534 }
495 535
496 SYSCALL_DEFINE2(ustat, unsigned, dev, struct u !! 536 asmlinkage long sys_ustat(unsigned dev, struct ustat __user * ubuf)
497 { 537 {
498 struct super_block *s; 538 struct super_block *s;
499 struct ustat tmp; 539 struct ustat tmp;
500 struct kstatfs sbuf; 540 struct kstatfs sbuf;
501 int err = -EINVAL; 541 int err = -EINVAL;
502 542
503 s = user_get_super(new_decode_dev(dev) 543 s = user_get_super(new_decode_dev(dev));
504 if (s == NULL) 544 if (s == NULL)
505 goto out; 545 goto out;
506 err = vfs_statfs(s->s_root, &sbuf); 546 err = vfs_statfs(s->s_root, &sbuf);
507 drop_super(s); 547 drop_super(s);
508 if (err) 548 if (err)
509 goto out; 549 goto out;
510 550
511 memset(&tmp,0,sizeof(struct ustat)); 551 memset(&tmp,0,sizeof(struct ustat));
512 tmp.f_tfree = sbuf.f_bfree; 552 tmp.f_tfree = sbuf.f_bfree;
513 tmp.f_tinode = sbuf.f_ffree; 553 tmp.f_tinode = sbuf.f_ffree;
514 554
515 err = copy_to_user(ubuf,&tmp,sizeof(st 555 err = copy_to_user(ubuf,&tmp,sizeof(struct ustat)) ? -EFAULT : 0;
516 out: 556 out:
517 return err; 557 return err;
518 } 558 }
519 559
520 /** 560 /**
>> 561 * mark_files_ro - mark all files read-only
>> 562 * @sb: superblock in question
>> 563 *
>> 564 * All files are marked read-only. We don't care about pending
>> 565 * delete files so this should be used in 'force' mode only.
>> 566 */
>> 567
>> 568 static void mark_files_ro(struct super_block *sb)
>> 569 {
>> 570 struct file *f;
>> 571 int idx;
>> 572
>> 573 idx = qrcu_read_lock(&sb->s_qrcu);
>> 574 percpu_list_fold(&sb->s_files);
>> 575 lock_list_for_each_entry(f, percpu_list_head(&sb->s_files), f_u.fu_llist) {
>> 576 if (S_ISREG(f->f_path.dentry->d_inode->i_mode) && file_count(f))
>> 577 f->f_mode &= ~FMODE_WRITE;
>> 578 }
>> 579 qrcu_read_unlock(&sb->s_qrcu, idx);
>> 580 }
>> 581
>> 582 /**
521 * do_remount_sb - asks filesystem to cha 583 * do_remount_sb - asks filesystem to change mount options.
522 * @sb: superblock in question 584 * @sb: superblock in question
523 * @flags: numeric part of options 585 * @flags: numeric part of options
524 * @data: the rest of options 586 * @data: the rest of options
525 * @force: whether or not to force the ch 587 * @force: whether or not to force the change
526 * 588 *
527 * Alters the mount options of a mounted 589 * Alters the mount options of a mounted file system.
528 */ 590 */
529 int do_remount_sb(struct super_block *sb, int 591 int do_remount_sb(struct super_block *sb, int flags, void *data, int force)
530 { 592 {
531 int retval; 593 int retval;
532 int remount_rw; <<
533 594
534 #ifdef CONFIG_BLOCK 595 #ifdef CONFIG_BLOCK
535 if (!(flags & MS_RDONLY) && bdev_read_ 596 if (!(flags & MS_RDONLY) && bdev_read_only(sb->s_bdev))
536 return -EACCES; 597 return -EACCES;
537 #endif 598 #endif
538 if (flags & MS_RDONLY) 599 if (flags & MS_RDONLY)
539 acct_auto_close(sb); 600 acct_auto_close(sb);
540 shrink_dcache_sb(sb); 601 shrink_dcache_sb(sb);
541 sync_filesystem(sb); !! 602 fsync_super(sb);
542 603
543 /* If we are remounting RDONLY and cur 604 /* If we are remounting RDONLY and current sb is read/write,
544 make sure there are no rw files ope 605 make sure there are no rw files opened */
545 if ((flags & MS_RDONLY) && !(sb->s_fla 606 if ((flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY)) {
546 if (force) 607 if (force)
547 mark_files_ro(sb); 608 mark_files_ro(sb);
548 else if (!fs_may_remount_ro(sb 609 else if (!fs_may_remount_ro(sb))
549 return -EBUSY; 610 return -EBUSY;
550 retval = vfs_dq_off(sb, 1); !! 611 DQUOT_OFF(sb);
551 if (retval < 0 && retval != -E <<
552 return -EBUSY; <<
553 } 612 }
554 remount_rw = !(flags & MS_RDONLY) && ( <<
555 613
556 if (sb->s_op->remount_fs) { 614 if (sb->s_op->remount_fs) {
>> 615 lock_super(sb);
557 retval = sb->s_op->remount_fs( 616 retval = sb->s_op->remount_fs(sb, &flags, data);
>> 617 unlock_super(sb);
558 if (retval) 618 if (retval)
559 return retval; 619 return retval;
560 } 620 }
561 sb->s_flags = (sb->s_flags & ~MS_RMT_M 621 sb->s_flags = (sb->s_flags & ~MS_RMT_MASK) | (flags & MS_RMT_MASK);
562 if (remount_rw) <<
563 vfs_dq_quota_on_remount(sb); <<
564 return 0; 622 return 0;
565 } 623 }
566 624
567 static void do_emergency_remount(struct work_s !! 625 static void do_emergency_remount(unsigned long foo)
568 { 626 {
569 struct super_block *sb; 627 struct super_block *sb;
570 628
571 spin_lock(&sb_lock); 629 spin_lock(&sb_lock);
572 list_for_each_entry(sb, &super_blocks, 630 list_for_each_entry(sb, &super_blocks, s_list) {
573 sb->s_count++; 631 sb->s_count++;
574 spin_unlock(&sb_lock); 632 spin_unlock(&sb_lock);
575 down_write(&sb->s_umount); !! 633 down_read(&sb->s_umount);
576 if (sb->s_root && sb->s_bdev & 634 if (sb->s_root && sb->s_bdev && !(sb->s_flags & MS_RDONLY)) {
577 /* 635 /*
578 * ->remount_fs needs 636 * ->remount_fs needs lock_kernel().
579 * 637 *
580 * What lock protects 638 * What lock protects sb->s_flags??
581 */ 639 */
>> 640 lock_kernel();
582 do_remount_sb(sb, MS_R 641 do_remount_sb(sb, MS_RDONLY, NULL, 1);
>> 642 unlock_kernel();
583 } 643 }
584 up_write(&sb->s_umount); !! 644 drop_super(sb);
585 put_super(sb); <<
586 spin_lock(&sb_lock); 645 spin_lock(&sb_lock);
587 } 646 }
588 spin_unlock(&sb_lock); 647 spin_unlock(&sb_lock);
589 kfree(work); <<
590 printk("Emergency Remount complete\n") 648 printk("Emergency Remount complete\n");
591 } 649 }
592 650
593 void emergency_remount(void) 651 void emergency_remount(void)
594 { 652 {
595 struct work_struct *work; !! 653 pdflush_operation(do_emergency_remount, 0);
596 <<
597 work = kmalloc(sizeof(*work), GFP_ATOM <<
598 if (work) { <<
599 INIT_WORK(work, do_emergency_r <<
600 schedule_work(work); <<
601 } <<
602 } 654 }
603 655
604 /* 656 /*
605 * Unnamed block devices are dummy devices use 657 * Unnamed block devices are dummy devices used by virtual
606 * filesystems which don't use real block-devi 658 * filesystems which don't use real block-devices. -- jrs
607 */ 659 */
608 660
609 static DEFINE_IDA(unnamed_dev_ida); !! 661 static struct idr unnamed_dev_idr;
610 static DEFINE_SPINLOCK(unnamed_dev_lock);/* pr 662 static DEFINE_SPINLOCK(unnamed_dev_lock);/* protects the above */
611 static int unnamed_dev_start = 0; /* don't bot <<
612 663
613 int set_anon_super(struct super_block *s, void 664 int set_anon_super(struct super_block *s, void *data)
614 { 665 {
615 int dev; 666 int dev;
616 int error; 667 int error;
617 668
618 retry: 669 retry:
619 if (ida_pre_get(&unnamed_dev_ida, GFP_ !! 670 if (idr_pre_get(&unnamed_dev_idr, GFP_ATOMIC) == 0)
620 return -ENOMEM; 671 return -ENOMEM;
621 spin_lock(&unnamed_dev_lock); 672 spin_lock(&unnamed_dev_lock);
622 error = ida_get_new_above(&unnamed_dev !! 673 error = idr_get_new(&unnamed_dev_idr, NULL, &dev);
623 if (!error) <<
624 unnamed_dev_start = dev + 1; <<
625 spin_unlock(&unnamed_dev_lock); 674 spin_unlock(&unnamed_dev_lock);
626 if (error == -EAGAIN) 675 if (error == -EAGAIN)
627 /* We raced and lost with anot 676 /* We raced and lost with another CPU. */
628 goto retry; 677 goto retry;
629 else if (error) 678 else if (error)
630 return -EAGAIN; 679 return -EAGAIN;
631 680
632 if ((dev & MAX_ID_MASK) == (1 << MINOR 681 if ((dev & MAX_ID_MASK) == (1 << MINORBITS)) {
633 spin_lock(&unnamed_dev_lock); 682 spin_lock(&unnamed_dev_lock);
634 ida_remove(&unnamed_dev_ida, d !! 683 idr_remove(&unnamed_dev_idr, dev);
635 if (unnamed_dev_start > dev) <<
636 unnamed_dev_start = de <<
637 spin_unlock(&unnamed_dev_lock) 684 spin_unlock(&unnamed_dev_lock);
638 return -EMFILE; 685 return -EMFILE;
639 } 686 }
640 s->s_dev = MKDEV(0, dev & MINORMASK); 687 s->s_dev = MKDEV(0, dev & MINORMASK);
641 return 0; 688 return 0;
642 } 689 }
643 690
644 EXPORT_SYMBOL(set_anon_super); 691 EXPORT_SYMBOL(set_anon_super);
645 692
646 void kill_anon_super(struct super_block *sb) 693 void kill_anon_super(struct super_block *sb)
647 { 694 {
648 int slot = MINOR(sb->s_dev); 695 int slot = MINOR(sb->s_dev);
649 696
650 generic_shutdown_super(sb); 697 generic_shutdown_super(sb);
651 spin_lock(&unnamed_dev_lock); 698 spin_lock(&unnamed_dev_lock);
652 ida_remove(&unnamed_dev_ida, slot); !! 699 idr_remove(&unnamed_dev_idr, slot);
653 if (slot < unnamed_dev_start) <<
654 unnamed_dev_start = slot; <<
655 spin_unlock(&unnamed_dev_lock); 700 spin_unlock(&unnamed_dev_lock);
656 } 701 }
657 702
658 EXPORT_SYMBOL(kill_anon_super); 703 EXPORT_SYMBOL(kill_anon_super);
659 704
>> 705 void __init unnamed_dev_init(void)
>> 706 {
>> 707 idr_init(&unnamed_dev_idr);
>> 708 }
>> 709
660 void kill_litter_super(struct super_block *sb) 710 void kill_litter_super(struct super_block *sb)
661 { 711 {
662 if (sb->s_root) 712 if (sb->s_root)
663 d_genocide(sb->s_root); 713 d_genocide(sb->s_root);
664 kill_anon_super(sb); 714 kill_anon_super(sb);
665 } 715 }
666 716
667 EXPORT_SYMBOL(kill_litter_super); 717 EXPORT_SYMBOL(kill_litter_super);
668 718
669 static int ns_test_super(struct super_block *s <<
670 { <<
671 return sb->s_fs_info == data; <<
672 } <<
673 <<
674 static int ns_set_super(struct super_block *sb <<
675 { <<
676 sb->s_fs_info = data; <<
677 return set_anon_super(sb, NULL); <<
678 } <<
679 <<
680 int get_sb_ns(struct file_system_type *fs_type <<
681 int (*fill_super)(struct super_block * <<
682 struct vfsmount *mnt) <<
683 { <<
684 struct super_block *sb; <<
685 <<
686 sb = sget(fs_type, ns_test_super, ns_s <<
687 if (IS_ERR(sb)) <<
688 return PTR_ERR(sb); <<
689 <<
690 if (!sb->s_root) { <<
691 int err; <<
692 sb->s_flags = flags; <<
693 err = fill_super(sb, data, fla <<
694 if (err) { <<
695 deactivate_locked_supe <<
696 return err; <<
697 } <<
698 <<
699 sb->s_flags |= MS_ACTIVE; <<
700 } <<
701 <<
702 simple_set_mnt(mnt, sb); <<
703 return 0; <<
704 } <<
705 <<
706 EXPORT_SYMBOL(get_sb_ns); <<
707 <<
708 #ifdef CONFIG_BLOCK 719 #ifdef CONFIG_BLOCK
709 static int set_bdev_super(struct super_block * 720 static int set_bdev_super(struct super_block *s, void *data)
710 { 721 {
711 s->s_bdev = data; 722 s->s_bdev = data;
712 s->s_dev = s->s_bdev->bd_dev; 723 s->s_dev = s->s_bdev->bd_dev;
713 return 0; 724 return 0;
714 } 725 }
715 726
716 static int test_bdev_super(struct super_block 727 static int test_bdev_super(struct super_block *s, void *data)
717 { 728 {
718 return (void *)s->s_bdev == data; 729 return (void *)s->s_bdev == data;
719 } 730 }
720 731
721 int get_sb_bdev(struct file_system_type *fs_ty 732 int get_sb_bdev(struct file_system_type *fs_type,
722 int flags, const char *dev_name, void 733 int flags, const char *dev_name, void *data,
723 int (*fill_super)(struct super_block * 734 int (*fill_super)(struct super_block *, void *, int),
724 struct vfsmount *mnt) 735 struct vfsmount *mnt)
725 { 736 {
726 struct block_device *bdev; 737 struct block_device *bdev;
727 struct super_block *s; 738 struct super_block *s;
728 fmode_t mode = FMODE_READ; <<
729 int error = 0; 739 int error = 0;
730 740
731 if (!(flags & MS_RDONLY)) !! 741 bdev = open_bdev_excl(dev_name, flags, fs_type);
732 mode |= FMODE_WRITE; <<
733 <<
734 bdev = open_bdev_exclusive(dev_name, m <<
735 if (IS_ERR(bdev)) 742 if (IS_ERR(bdev))
736 return PTR_ERR(bdev); 743 return PTR_ERR(bdev);
737 744
738 /* 745 /*
739 * once the super is inserted into the 746 * once the super is inserted into the list by sget, s_umount
740 * will protect the lockfs code from t 747 * will protect the lockfs code from trying to start a snapshot
741 * while we are mounting 748 * while we are mounting
742 */ 749 */
743 down(&bdev->bd_mount_sem); 750 down(&bdev->bd_mount_sem);
744 s = sget(fs_type, test_bdev_super, set 751 s = sget(fs_type, test_bdev_super, set_bdev_super, bdev);
745 up(&bdev->bd_mount_sem); 752 up(&bdev->bd_mount_sem);
746 if (IS_ERR(s)) 753 if (IS_ERR(s))
747 goto error_s; 754 goto error_s;
748 755
749 if (s->s_root) { 756 if (s->s_root) {
750 if ((flags ^ s->s_flags) & MS_ 757 if ((flags ^ s->s_flags) & MS_RDONLY) {
751 deactivate_locked_supe !! 758 up_write(&s->s_umount);
>> 759 deactivate_super(s);
752 error = -EBUSY; 760 error = -EBUSY;
753 goto error_bdev; 761 goto error_bdev;
754 } 762 }
755 763
756 close_bdev_exclusive(bdev, mod !! 764 close_bdev_excl(bdev);
757 } else { 765 } else {
758 char b[BDEVNAME_SIZE]; 766 char b[BDEVNAME_SIZE];
759 767
760 s->s_flags = flags; 768 s->s_flags = flags;
761 s->s_mode = mode; <<
762 strlcpy(s->s_id, bdevname(bdev 769 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
763 sb_set_blocksize(s, block_size 770 sb_set_blocksize(s, block_size(bdev));
764 error = fill_super(s, data, fl 771 error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
765 if (error) { 772 if (error) {
766 deactivate_locked_supe !! 773 up_write(&s->s_umount);
>> 774 deactivate_super(s);
767 goto error; 775 goto error;
768 } 776 }
769 777
770 s->s_flags |= MS_ACTIVE; 778 s->s_flags |= MS_ACTIVE;
771 bdev->bd_super = s; <<
772 } 779 }
773 780
774 simple_set_mnt(mnt, s); !! 781 return simple_set_mnt(mnt, s);
775 return 0; <<
776 782
777 error_s: 783 error_s:
778 error = PTR_ERR(s); 784 error = PTR_ERR(s);
779 error_bdev: 785 error_bdev:
780 close_bdev_exclusive(bdev, mode); !! 786 close_bdev_excl(bdev);
781 error: 787 error:
782 return error; 788 return error;
783 } 789 }
784 790
785 EXPORT_SYMBOL(get_sb_bdev); 791 EXPORT_SYMBOL(get_sb_bdev);
786 792
787 void kill_block_super(struct super_block *sb) 793 void kill_block_super(struct super_block *sb)
788 { 794 {
789 struct block_device *bdev = sb->s_bdev 795 struct block_device *bdev = sb->s_bdev;
790 fmode_t mode = sb->s_mode; <<
791 796
792 bdev->bd_super = NULL; <<
793 generic_shutdown_super(sb); 797 generic_shutdown_super(sb);
794 sync_blockdev(bdev); 798 sync_blockdev(bdev);
795 close_bdev_exclusive(bdev, mode); !! 799 close_bdev_excl(bdev);
796 } 800 }
797 801
798 EXPORT_SYMBOL(kill_block_super); 802 EXPORT_SYMBOL(kill_block_super);
799 #endif 803 #endif
800 804
801 int get_sb_nodev(struct file_system_type *fs_t 805 int get_sb_nodev(struct file_system_type *fs_type,
802 int flags, void *data, 806 int flags, void *data,
803 int (*fill_super)(struct super_block * 807 int (*fill_super)(struct super_block *, void *, int),
804 struct vfsmount *mnt) 808 struct vfsmount *mnt)
805 { 809 {
806 int error; 810 int error;
807 struct super_block *s = sget(fs_type, 811 struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL);
808 812
809 if (IS_ERR(s)) 813 if (IS_ERR(s))
810 return PTR_ERR(s); 814 return PTR_ERR(s);
811 815
812 s->s_flags = flags; 816 s->s_flags = flags;
813 817
814 error = fill_super(s, data, flags & MS 818 error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
815 if (error) { 819 if (error) {
816 deactivate_locked_super(s); !! 820 up_write(&s->s_umount);
>> 821 deactivate_super(s);
817 return error; 822 return error;
818 } 823 }
819 s->s_flags |= MS_ACTIVE; 824 s->s_flags |= MS_ACTIVE;
820 simple_set_mnt(mnt, s); !! 825 return simple_set_mnt(mnt, s);
821 return 0; <<
822 } 826 }
823 827
824 EXPORT_SYMBOL(get_sb_nodev); 828 EXPORT_SYMBOL(get_sb_nodev);
825 829
826 static int compare_single(struct super_block * 830 static int compare_single(struct super_block *s, void *p)
827 { 831 {
828 return 1; 832 return 1;
829 } 833 }
830 834
831 int get_sb_single(struct file_system_type *fs_ 835 int get_sb_single(struct file_system_type *fs_type,
832 int flags, void *data, 836 int flags, void *data,
833 int (*fill_super)(struct super_block * 837 int (*fill_super)(struct super_block *, void *, int),
834 struct vfsmount *mnt) 838 struct vfsmount *mnt)
835 { 839 {
836 struct super_block *s; 840 struct super_block *s;
837 int error; 841 int error;
838 842
839 s = sget(fs_type, compare_single, set_ 843 s = sget(fs_type, compare_single, set_anon_super, NULL);
840 if (IS_ERR(s)) 844 if (IS_ERR(s))
841 return PTR_ERR(s); 845 return PTR_ERR(s);
842 if (!s->s_root) { 846 if (!s->s_root) {
843 s->s_flags = flags; 847 s->s_flags = flags;
844 error = fill_super(s, data, fl 848 error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
845 if (error) { 849 if (error) {
846 deactivate_locked_supe !! 850 up_write(&s->s_umount);
>> 851 deactivate_super(s);
847 return error; 852 return error;
848 } 853 }
849 s->s_flags |= MS_ACTIVE; 854 s->s_flags |= MS_ACTIVE;
850 } 855 }
851 do_remount_sb(s, flags, data, 0); 856 do_remount_sb(s, flags, data, 0);
852 simple_set_mnt(mnt, s); !! 857 return simple_set_mnt(mnt, s);
853 return 0; <<
854 } 858 }
855 859
856 EXPORT_SYMBOL(get_sb_single); 860 EXPORT_SYMBOL(get_sb_single);
857 861
858 struct vfsmount * 862 struct vfsmount *
859 vfs_kern_mount(struct file_system_type *type, 863 vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data)
860 { 864 {
861 struct vfsmount *mnt; 865 struct vfsmount *mnt;
862 char *secdata = NULL; 866 char *secdata = NULL;
863 int error; 867 int error;
864 868
865 if (!type) 869 if (!type)
866 return ERR_PTR(-ENODEV); 870 return ERR_PTR(-ENODEV);
867 871
868 error = -ENOMEM; 872 error = -ENOMEM;
869 mnt = alloc_vfsmnt(name); 873 mnt = alloc_vfsmnt(name);
870 if (!mnt) 874 if (!mnt)
871 goto out; 875 goto out;
872 876
873 if (data && !(type->fs_flags & FS_BINA 877 if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) {
874 secdata = alloc_secdata(); 878 secdata = alloc_secdata();
875 if (!secdata) 879 if (!secdata)
876 goto out_mnt; 880 goto out_mnt;
877 881
878 error = security_sb_copy_data( 882 error = security_sb_copy_data(data, secdata);
879 if (error) 883 if (error)
880 goto out_free_secdata; 884 goto out_free_secdata;
881 } 885 }
882 886
883 error = type->get_sb(type, flags, name 887 error = type->get_sb(type, flags, name, data, mnt);
884 if (error < 0) 888 if (error < 0)
885 goto out_free_secdata; 889 goto out_free_secdata;
886 BUG_ON(!mnt->mnt_sb); 890 BUG_ON(!mnt->mnt_sb);
887 891
888 error = security_sb_kern_mount(mnt->mn !! 892 error = security_sb_kern_mount(mnt->mnt_sb, secdata);
889 if (error) 893 if (error)
890 goto out_sb; 894 goto out_sb;
891 895
892 mnt->mnt_mountpoint = mnt->mnt_root; 896 mnt->mnt_mountpoint = mnt->mnt_root;
893 mnt->mnt_parent = mnt; 897 mnt->mnt_parent = mnt;
894 up_write(&mnt->mnt_sb->s_umount); 898 up_write(&mnt->mnt_sb->s_umount);
895 free_secdata(secdata); 899 free_secdata(secdata);
896 return mnt; 900 return mnt;
897 out_sb: 901 out_sb:
898 dput(mnt->mnt_root); 902 dput(mnt->mnt_root);
899 deactivate_locked_super(mnt->mnt_sb); !! 903 up_write(&mnt->mnt_sb->s_umount);
>> 904 deactivate_super(mnt->mnt_sb);
900 out_free_secdata: 905 out_free_secdata:
901 free_secdata(secdata); 906 free_secdata(secdata);
902 out_mnt: 907 out_mnt:
903 free_vfsmnt(mnt); 908 free_vfsmnt(mnt);
904 out: 909 out:
905 return ERR_PTR(error); 910 return ERR_PTR(error);
906 } 911 }
907 912
908 EXPORT_SYMBOL_GPL(vfs_kern_mount); 913 EXPORT_SYMBOL_GPL(vfs_kern_mount);
909 914
910 static struct vfsmount *fs_set_subtype(struct 915 static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype)
911 { 916 {
912 int err; 917 int err;
913 const char *subtype = strchr(fstype, ' 918 const char *subtype = strchr(fstype, '.');
914 if (subtype) { 919 if (subtype) {
915 subtype++; 920 subtype++;
916 err = -EINVAL; 921 err = -EINVAL;
917 if (!subtype[0]) 922 if (!subtype[0])
918 goto err; 923 goto err;
919 } else 924 } else
920 subtype = ""; 925 subtype = "";
921 926
922 mnt->mnt_sb->s_subtype = kstrdup(subty 927 mnt->mnt_sb->s_subtype = kstrdup(subtype, GFP_KERNEL);
923 err = -ENOMEM; 928 err = -ENOMEM;
924 if (!mnt->mnt_sb->s_subtype) 929 if (!mnt->mnt_sb->s_subtype)
925 goto err; 930 goto err;
926 return mnt; 931 return mnt;
927 932
928 err: 933 err:
929 mntput(mnt); 934 mntput(mnt);
930 return ERR_PTR(err); 935 return ERR_PTR(err);
931 } 936 }
932 937
933 struct vfsmount * 938 struct vfsmount *
934 do_kern_mount(const char *fstype, int flags, c 939 do_kern_mount(const char *fstype, int flags, const char *name, void *data)
935 { 940 {
936 struct file_system_type *type = get_fs 941 struct file_system_type *type = get_fs_type(fstype);
937 struct vfsmount *mnt; 942 struct vfsmount *mnt;
938 if (!type) 943 if (!type)
939 return ERR_PTR(-ENODEV); 944 return ERR_PTR(-ENODEV);
940 mnt = vfs_kern_mount(type, flags, name 945 mnt = vfs_kern_mount(type, flags, name, data);
941 if (!IS_ERR(mnt) && (type->fs_flags & 946 if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) &&
942 !mnt->mnt_sb->s_subtype) 947 !mnt->mnt_sb->s_subtype)
943 mnt = fs_set_subtype(mnt, fsty 948 mnt = fs_set_subtype(mnt, fstype);
944 put_filesystem(type); 949 put_filesystem(type);
945 return mnt; 950 return mnt;
946 } 951 }
947 EXPORT_SYMBOL_GPL(do_kern_mount); 952 EXPORT_SYMBOL_GPL(do_kern_mount);
948 953
949 struct vfsmount *kern_mount_data(struct file_s 954 struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
950 { 955 {
951 return vfs_kern_mount(type, MS_KERNMOU 956 return vfs_kern_mount(type, MS_KERNMOUNT, type->name, data);
952 } 957 }
953 958
954 EXPORT_SYMBOL_GPL(kern_mount_data); 959 EXPORT_SYMBOL_GPL(kern_mount_data);
955 960
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