Commit | Line | Data |
---|---|---|
f79e2abb AM |
1 | /* |
2 | * High-level sync()-related operations | |
3 | */ | |
4 | ||
5 | #include <linux/kernel.h> | |
6 | #include <linux/file.h> | |
7 | #include <linux/fs.h> | |
5a0e3ad6 | 8 | #include <linux/slab.h> |
630d9c47 | 9 | #include <linux/export.h> |
b7ed78f5 | 10 | #include <linux/namei.h> |
914e2637 | 11 | #include <linux/sched.h> |
f79e2abb AM |
12 | #include <linux/writeback.h> |
13 | #include <linux/syscalls.h> | |
14 | #include <linux/linkage.h> | |
15 | #include <linux/pagemap.h> | |
cf9a2ae8 | 16 | #include <linux/quotaops.h> |
5129a469 | 17 | #include <linux/backing-dev.h> |
5a3e5cb8 | 18 | #include "internal.h" |
f79e2abb AM |
19 | |
20 | #define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \ | |
21 | SYNC_FILE_RANGE_WAIT_AFTER) | |
22 | ||
c15c54f5 | 23 | /* |
d8a8559c JA |
24 | * Do the filesystem syncing work. For simple filesystems |
25 | * writeback_inodes_sb(sb) just dirties buffers with inodes so we have to | |
26 | * submit IO for these buffers via __sync_blockdev(). This also speeds up the | |
27 | * wait == 1 case since in that case write_inode() functions do | |
28 | * sync_dirty_buffer() and thus effectively write one block at a time. | |
c15c54f5 | 29 | */ |
60b0680f | 30 | static int __sync_filesystem(struct super_block *sb, int wait) |
c15c54f5 | 31 | { |
5fb324ad | 32 | if (wait) |
d8a8559c | 33 | sync_inodes_sb(sb); |
5fb324ad | 34 | else |
0e175a18 | 35 | writeback_inodes_sb(sb, WB_REASON_SYNC); |
5fb324ad | 36 | |
c15c54f5 JK |
37 | if (sb->s_op->sync_fs) |
38 | sb->s_op->sync_fs(sb, wait); | |
39 | return __sync_blockdev(sb->s_bdev, wait); | |
40 | } | |
41 | ||
42 | /* | |
43 | * Write out and wait upon all dirty data associated with this | |
44 | * superblock. Filesystem data as well as the underlying block | |
45 | * device. Takes the superblock lock. | |
46 | */ | |
60b0680f | 47 | int sync_filesystem(struct super_block *sb) |
c15c54f5 JK |
48 | { |
49 | int ret; | |
50 | ||
5af7926f CH |
51 | /* |
52 | * We need to be protected against the filesystem going from | |
53 | * r/o to r/w or vice versa. | |
54 | */ | |
55 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); | |
56 | ||
57 | /* | |
58 | * No point in syncing out anything if the filesystem is read-only. | |
59 | */ | |
60 | if (sb->s_flags & MS_RDONLY) | |
61 | return 0; | |
62 | ||
60b0680f | 63 | ret = __sync_filesystem(sb, 0); |
c15c54f5 JK |
64 | if (ret < 0) |
65 | return ret; | |
60b0680f | 66 | return __sync_filesystem(sb, 1); |
c15c54f5 | 67 | } |
60b0680f | 68 | EXPORT_SYMBOL_GPL(sync_filesystem); |
c15c54f5 | 69 | |
b3de6531 | 70 | static void sync_inodes_one_sb(struct super_block *sb, void *arg) |
01a05b33 | 71 | { |
95f28604 | 72 | if (!(sb->s_flags & MS_RDONLY)) |
b3de6531 | 73 | sync_inodes_sb(sb); |
01a05b33 | 74 | } |
b3de6531 JK |
75 | |
76 | static void writeback_inodes_one_sb(struct super_block *sb, void *arg) | |
c15c54f5 | 77 | { |
b3de6531 JK |
78 | if (!(sb->s_flags & MS_RDONLY)) |
79 | writeback_inodes_sb(sb, WB_REASON_SYNC); | |
80 | } | |
81 | ||
82 | static void sync_fs_one_sb(struct super_block *sb, void *arg) | |
83 | { | |
84 | if (!(sb->s_flags & MS_RDONLY) && sb->s_op->sync_fs) | |
85 | sb->s_op->sync_fs(sb, *(int *)arg); | |
86 | } | |
87 | ||
d0e91b13 | 88 | static void fdatawrite_one_bdev(struct block_device *bdev, void *arg) |
b3de6531 | 89 | { |
d0e91b13 | 90 | filemap_fdatawrite(bdev->bd_inode->i_mapping); |
a8c7176b JK |
91 | } |
92 | ||
d0e91b13 | 93 | static void fdatawait_one_bdev(struct block_device *bdev, void *arg) |
a8c7176b | 94 | { |
d0e91b13 | 95 | filemap_fdatawait(bdev->bd_inode->i_mapping); |
c15c54f5 JK |
96 | } |
97 | ||
3beab0b4 ZY |
98 | /* |
99 | * sync everything. Start out by waking pdflush, because that writes back | |
100 | * all queues in parallel. | |
101 | */ | |
5cee5815 | 102 | SYSCALL_DEFINE0(sync) |
cf9a2ae8 | 103 | { |
b3de6531 JK |
104 | int nowait = 0, wait = 1; |
105 | ||
0e175a18 | 106 | wakeup_flusher_threads(0, WB_REASON_SYNC); |
b3de6531 JK |
107 | iterate_supers(writeback_inodes_one_sb, NULL); |
108 | iterate_supers(sync_fs_one_sb, &nowait); | |
b3de6531 JK |
109 | iterate_supers(sync_inodes_one_sb, NULL); |
110 | iterate_supers(sync_fs_one_sb, &wait); | |
d0e91b13 JK |
111 | iterate_bdevs(fdatawrite_one_bdev, NULL); |
112 | iterate_bdevs(fdatawait_one_bdev, NULL); | |
cf9a2ae8 DH |
113 | if (unlikely(laptop_mode)) |
114 | laptop_sync_completion(); | |
cf9a2ae8 DH |
115 | return 0; |
116 | } | |
117 | ||
a2a9537a JA |
118 | static void do_sync_work(struct work_struct *work) |
119 | { | |
b3de6531 JK |
120 | int nowait = 0; |
121 | ||
5cee5815 JK |
122 | /* |
123 | * Sync twice to reduce the possibility we skipped some inodes / pages | |
124 | * because they were temporarily locked | |
125 | */ | |
b3de6531 JK |
126 | iterate_supers(sync_inodes_one_sb, &nowait); |
127 | iterate_supers(sync_fs_one_sb, &nowait); | |
d0e91b13 | 128 | iterate_bdevs(fdatawrite_one_bdev, NULL); |
b3de6531 JK |
129 | iterate_supers(sync_inodes_one_sb, &nowait); |
130 | iterate_supers(sync_fs_one_sb, &nowait); | |
d0e91b13 | 131 | iterate_bdevs(fdatawrite_one_bdev, NULL); |
5cee5815 | 132 | printk("Emergency Sync complete\n"); |
a2a9537a JA |
133 | kfree(work); |
134 | } | |
135 | ||
cf9a2ae8 DH |
136 | void emergency_sync(void) |
137 | { | |
a2a9537a JA |
138 | struct work_struct *work; |
139 | ||
140 | work = kmalloc(sizeof(*work), GFP_ATOMIC); | |
141 | if (work) { | |
142 | INIT_WORK(work, do_sync_work); | |
143 | schedule_work(work); | |
144 | } | |
cf9a2ae8 DH |
145 | } |
146 | ||
b7ed78f5 SW |
147 | /* |
148 | * sync a single super | |
149 | */ | |
150 | SYSCALL_DEFINE1(syncfs, int, fd) | |
151 | { | |
152 | struct file *file; | |
153 | struct super_block *sb; | |
154 | int ret; | |
155 | int fput_needed; | |
156 | ||
157 | file = fget_light(fd, &fput_needed); | |
158 | if (!file) | |
159 | return -EBADF; | |
160 | sb = file->f_dentry->d_sb; | |
161 | ||
162 | down_read(&sb->s_umount); | |
163 | ret = sync_filesystem(sb); | |
164 | up_read(&sb->s_umount); | |
165 | ||
166 | fput_light(file, fput_needed); | |
167 | return ret; | |
168 | } | |
169 | ||
4c728ef5 | 170 | /** |
148f948b | 171 | * vfs_fsync_range - helper to sync a range of data & metadata to disk |
4c728ef5 | 172 | * @file: file to sync |
148f948b JK |
173 | * @start: offset in bytes of the beginning of data range to sync |
174 | * @end: offset in bytes of the end of data range (inclusive) | |
175 | * @datasync: perform only datasync | |
4c728ef5 | 176 | * |
148f948b JK |
177 | * Write back data in range @start..@end and metadata for @file to disk. If |
178 | * @datasync is set only metadata needed to access modified file data is | |
179 | * written. | |
4c728ef5 | 180 | */ |
8018ab05 | 181 | int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync) |
cf9a2ae8 | 182 | { |
02c24a82 JB |
183 | if (!file->f_op || !file->f_op->fsync) |
184 | return -EINVAL; | |
185 | return file->f_op->fsync(file, start, end, datasync); | |
cf9a2ae8 | 186 | } |
148f948b JK |
187 | EXPORT_SYMBOL(vfs_fsync_range); |
188 | ||
189 | /** | |
190 | * vfs_fsync - perform a fsync or fdatasync on a file | |
191 | * @file: file to sync | |
148f948b JK |
192 | * @datasync: only perform a fdatasync operation |
193 | * | |
194 | * Write back data and metadata for @file to disk. If @datasync is | |
195 | * set only metadata needed to access modified file data is written. | |
148f948b | 196 | */ |
8018ab05 | 197 | int vfs_fsync(struct file *file, int datasync) |
148f948b | 198 | { |
8018ab05 | 199 | return vfs_fsync_range(file, 0, LLONG_MAX, datasync); |
148f948b | 200 | } |
4c728ef5 | 201 | EXPORT_SYMBOL(vfs_fsync); |
cf9a2ae8 | 202 | |
4c728ef5 | 203 | static int do_fsync(unsigned int fd, int datasync) |
cf9a2ae8 DH |
204 | { |
205 | struct file *file; | |
206 | int ret = -EBADF; | |
c2bd6c11 | 207 | int fput_needed; |
cf9a2ae8 | 208 | |
c2bd6c11 | 209 | file = fget_light(fd, &fput_needed); |
cf9a2ae8 | 210 | if (file) { |
8018ab05 | 211 | ret = vfs_fsync(file, datasync); |
c2bd6c11 | 212 | fput_light(file, fput_needed); |
cf9a2ae8 DH |
213 | } |
214 | return ret; | |
215 | } | |
216 | ||
a5f8fa9e | 217 | SYSCALL_DEFINE1(fsync, unsigned int, fd) |
cf9a2ae8 | 218 | { |
4c728ef5 | 219 | return do_fsync(fd, 0); |
cf9a2ae8 DH |
220 | } |
221 | ||
a5f8fa9e | 222 | SYSCALL_DEFINE1(fdatasync, unsigned int, fd) |
cf9a2ae8 | 223 | { |
4c728ef5 | 224 | return do_fsync(fd, 1); |
cf9a2ae8 DH |
225 | } |
226 | ||
148f948b JK |
227 | /** |
228 | * generic_write_sync - perform syncing after a write if file / inode is sync | |
229 | * @file: file to which the write happened | |
230 | * @pos: offset where the write started | |
231 | * @count: length of the write | |
232 | * | |
233 | * This is just a simple wrapper about our general syncing function. | |
234 | */ | |
235 | int generic_write_sync(struct file *file, loff_t pos, loff_t count) | |
236 | { | |
6b2f3d1f | 237 | if (!(file->f_flags & O_DSYNC) && !IS_SYNC(file->f_mapping->host)) |
148f948b | 238 | return 0; |
8018ab05 | 239 | return vfs_fsync_range(file, pos, pos + count - 1, |
6b2f3d1f | 240 | (file->f_flags & __O_SYNC) ? 0 : 1); |
148f948b JK |
241 | } |
242 | EXPORT_SYMBOL(generic_write_sync); | |
243 | ||
f79e2abb AM |
244 | /* |
245 | * sys_sync_file_range() permits finely controlled syncing over a segment of | |
246 | * a file in the range offset .. (offset+nbytes-1) inclusive. If nbytes is | |
247 | * zero then sys_sync_file_range() will operate from offset out to EOF. | |
248 | * | |
249 | * The flag bits are: | |
250 | * | |
251 | * SYNC_FILE_RANGE_WAIT_BEFORE: wait upon writeout of all pages in the range | |
252 | * before performing the write. | |
253 | * | |
254 | * SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the | |
cce77081 PM |
255 | * range which are not presently under writeback. Note that this may block for |
256 | * significant periods due to exhaustion of disk request structures. | |
f79e2abb AM |
257 | * |
258 | * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range | |
259 | * after performing the write. | |
260 | * | |
261 | * Useful combinations of the flag bits are: | |
262 | * | |
263 | * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE: ensures that all pages | |
264 | * in the range which were dirty on entry to sys_sync_file_range() are placed | |
265 | * under writeout. This is a start-write-for-data-integrity operation. | |
266 | * | |
267 | * SYNC_FILE_RANGE_WRITE: start writeout of all dirty pages in the range which | |
268 | * are not presently under writeout. This is an asynchronous flush-to-disk | |
269 | * operation. Not suitable for data integrity operations. | |
270 | * | |
271 | * SYNC_FILE_RANGE_WAIT_BEFORE (or SYNC_FILE_RANGE_WAIT_AFTER): wait for | |
272 | * completion of writeout of all pages in the range. This will be used after an | |
273 | * earlier SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE operation to wait | |
274 | * for that operation to complete and to return the result. | |
275 | * | |
276 | * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE|SYNC_FILE_RANGE_WAIT_AFTER: | |
277 | * a traditional sync() operation. This is a write-for-data-integrity operation | |
278 | * which will ensure that all pages in the range which were dirty on entry to | |
279 | * sys_sync_file_range() are committed to disk. | |
280 | * | |
281 | * | |
282 | * SYNC_FILE_RANGE_WAIT_BEFORE and SYNC_FILE_RANGE_WAIT_AFTER will detect any | |
283 | * I/O errors or ENOSPC conditions and will return those to the caller, after | |
284 | * clearing the EIO and ENOSPC flags in the address_space. | |
285 | * | |
286 | * It should be noted that none of these operations write out the file's | |
287 | * metadata. So unless the application is strictly performing overwrites of | |
288 | * already-instantiated disk blocks, there are no guarantees here that the data | |
289 | * will be available after a crash. | |
290 | */ | |
6673e0c3 HC |
291 | SYSCALL_DEFINE(sync_file_range)(int fd, loff_t offset, loff_t nbytes, |
292 | unsigned int flags) | |
f79e2abb AM |
293 | { |
294 | int ret; | |
295 | struct file *file; | |
7a0ad10c | 296 | struct address_space *mapping; |
f79e2abb AM |
297 | loff_t endbyte; /* inclusive */ |
298 | int fput_needed; | |
299 | umode_t i_mode; | |
300 | ||
301 | ret = -EINVAL; | |
302 | if (flags & ~VALID_FLAGS) | |
303 | goto out; | |
304 | ||
305 | endbyte = offset + nbytes; | |
306 | ||
307 | if ((s64)offset < 0) | |
308 | goto out; | |
309 | if ((s64)endbyte < 0) | |
310 | goto out; | |
311 | if (endbyte < offset) | |
312 | goto out; | |
313 | ||
314 | if (sizeof(pgoff_t) == 4) { | |
315 | if (offset >= (0x100000000ULL << PAGE_CACHE_SHIFT)) { | |
316 | /* | |
317 | * The range starts outside a 32 bit machine's | |
318 | * pagecache addressing capabilities. Let it "succeed" | |
319 | */ | |
320 | ret = 0; | |
321 | goto out; | |
322 | } | |
323 | if (endbyte >= (0x100000000ULL << PAGE_CACHE_SHIFT)) { | |
324 | /* | |
325 | * Out to EOF | |
326 | */ | |
327 | nbytes = 0; | |
328 | } | |
329 | } | |
330 | ||
331 | if (nbytes == 0) | |
111ebb6e | 332 | endbyte = LLONG_MAX; |
f79e2abb AM |
333 | else |
334 | endbyte--; /* inclusive */ | |
335 | ||
336 | ret = -EBADF; | |
337 | file = fget_light(fd, &fput_needed); | |
338 | if (!file) | |
339 | goto out; | |
340 | ||
0f7fc9e4 | 341 | i_mode = file->f_path.dentry->d_inode->i_mode; |
f79e2abb AM |
342 | ret = -ESPIPE; |
343 | if (!S_ISREG(i_mode) && !S_ISBLK(i_mode) && !S_ISDIR(i_mode) && | |
344 | !S_ISLNK(i_mode)) | |
345 | goto out_put; | |
346 | ||
7a0ad10c CH |
347 | mapping = file->f_mapping; |
348 | if (!mapping) { | |
349 | ret = -EINVAL; | |
350 | goto out_put; | |
351 | } | |
352 | ||
353 | ret = 0; | |
354 | if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) { | |
355 | ret = filemap_fdatawait_range(mapping, offset, endbyte); | |
356 | if (ret < 0) | |
357 | goto out_put; | |
358 | } | |
359 | ||
360 | if (flags & SYNC_FILE_RANGE_WRITE) { | |
361 | ret = filemap_fdatawrite_range(mapping, offset, endbyte); | |
362 | if (ret < 0) | |
363 | goto out_put; | |
364 | } | |
365 | ||
366 | if (flags & SYNC_FILE_RANGE_WAIT_AFTER) | |
367 | ret = filemap_fdatawait_range(mapping, offset, endbyte); | |
368 | ||
f79e2abb AM |
369 | out_put: |
370 | fput_light(file, fput_needed); | |
371 | out: | |
372 | return ret; | |
373 | } | |
6673e0c3 HC |
374 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
375 | asmlinkage long SyS_sync_file_range(long fd, loff_t offset, loff_t nbytes, | |
376 | long flags) | |
377 | { | |
378 | return SYSC_sync_file_range((int) fd, offset, nbytes, | |
379 | (unsigned int) flags); | |
380 | } | |
381 | SYSCALL_ALIAS(sys_sync_file_range, SyS_sync_file_range); | |
382 | #endif | |
f79e2abb | 383 | |
edd5cd4a DW |
384 | /* It would be nice if people remember that not all the world's an i386 |
385 | when they introduce new system calls */ | |
6673e0c3 HC |
386 | SYSCALL_DEFINE(sync_file_range2)(int fd, unsigned int flags, |
387 | loff_t offset, loff_t nbytes) | |
edd5cd4a DW |
388 | { |
389 | return sys_sync_file_range(fd, offset, nbytes, flags); | |
390 | } | |
6673e0c3 HC |
391 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
392 | asmlinkage long SyS_sync_file_range2(long fd, long flags, | |
393 | loff_t offset, loff_t nbytes) | |
394 | { | |
395 | return SYSC_sync_file_range2((int) fd, (unsigned int) flags, | |
396 | offset, nbytes); | |
397 | } | |
398 | SYSCALL_ALIAS(sys_sync_file_range2, SyS_sync_file_range2); | |
399 | #endif |