Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
f79e2abb AM |
2 | /* |
3 | * High-level sync()-related operations | |
4 | */ | |
5 | ||
70164eb6 | 6 | #include <linux/blkdev.h> |
f79e2abb AM |
7 | #include <linux/kernel.h> |
8 | #include <linux/file.h> | |
9 | #include <linux/fs.h> | |
5a0e3ad6 | 10 | #include <linux/slab.h> |
630d9c47 | 11 | #include <linux/export.h> |
b7ed78f5 | 12 | #include <linux/namei.h> |
914e2637 | 13 | #include <linux/sched.h> |
f79e2abb AM |
14 | #include <linux/writeback.h> |
15 | #include <linux/syscalls.h> | |
16 | #include <linux/linkage.h> | |
17 | #include <linux/pagemap.h> | |
cf9a2ae8 | 18 | #include <linux/quotaops.h> |
5129a469 | 19 | #include <linux/backing-dev.h> |
5a3e5cb8 | 20 | #include "internal.h" |
f79e2abb AM |
21 | |
22 | #define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \ | |
23 | SYNC_FILE_RANGE_WAIT_AFTER) | |
24 | ||
c15c54f5 JK |
25 | /* |
26 | * Write out and wait upon all dirty data associated with this | |
27 | * superblock. Filesystem data as well as the underlying block | |
28 | * device. Takes the superblock lock. | |
29 | */ | |
60b0680f | 30 | int sync_filesystem(struct super_block *sb) |
c15c54f5 JK |
31 | { |
32 | int ret; | |
33 | ||
5af7926f CH |
34 | /* |
35 | * We need to be protected against the filesystem going from | |
36 | * r/o to r/w or vice versa. | |
37 | */ | |
38 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); | |
39 | ||
40 | /* | |
41 | * No point in syncing out anything if the filesystem is read-only. | |
42 | */ | |
bc98a42c | 43 | if (sb_rdonly(sb)) |
5af7926f CH |
44 | return 0; |
45 | ||
9a208ba5 CH |
46 | /* |
47 | * Do the filesystem syncing work. For simple filesystems | |
48 | * writeback_inodes_sb(sb) just dirties buffers with inodes so we have | |
70164eb6 | 49 | * to submit I/O for these buffers via sync_blockdev(). This also |
9a208ba5 CH |
50 | * speeds up the wait == 1 case since in that case write_inode() |
51 | * methods call sync_dirty_buffer() and thus effectively write one block | |
52 | * at a time. | |
53 | */ | |
54 | writeback_inodes_sb(sb, WB_REASON_SYNC); | |
55 | if (sb->s_op->sync_fs) | |
56 | sb->s_op->sync_fs(sb, 0); | |
70164eb6 | 57 | ret = sync_blockdev_nowait(sb->s_bdev); |
c15c54f5 JK |
58 | if (ret < 0) |
59 | return ret; | |
9a208ba5 CH |
60 | |
61 | sync_inodes_sb(sb); | |
62 | if (sb->s_op->sync_fs) | |
63 | sb->s_op->sync_fs(sb, 1); | |
70164eb6 | 64 | return sync_blockdev(sb->s_bdev); |
c15c54f5 | 65 | } |
10096fb1 | 66 | EXPORT_SYMBOL(sync_filesystem); |
c15c54f5 | 67 | |
b3de6531 | 68 | static void sync_inodes_one_sb(struct super_block *sb, void *arg) |
01a05b33 | 69 | { |
bc98a42c | 70 | if (!sb_rdonly(sb)) |
0dc83bd3 | 71 | sync_inodes_sb(sb); |
01a05b33 | 72 | } |
b3de6531 | 73 | |
b3de6531 JK |
74 | static void sync_fs_one_sb(struct super_block *sb, void *arg) |
75 | { | |
32b1924b KK |
76 | if (!sb_rdonly(sb) && !(sb->s_iflags & SB_I_SKIP_SYNC) && |
77 | sb->s_op->sync_fs) | |
b3de6531 JK |
78 | sb->s_op->sync_fs(sb, *(int *)arg); |
79 | } | |
80 | ||
3beab0b4 | 81 | /* |
4ea425b6 JK |
82 | * Sync everything. We start by waking flusher threads so that most of |
83 | * writeback runs on all devices in parallel. Then we sync all inodes reliably | |
84 | * which effectively also waits for all flusher threads to finish doing | |
85 | * writeback. At this point all data is on disk so metadata should be stable | |
86 | * and we tell filesystems to sync their metadata via ->sync_fs() calls. | |
87 | * Finally, we writeout all block devices because some filesystems (e.g. ext2) | |
88 | * just write metadata (such as inodes or bitmaps) to block device page cache | |
89 | * and do not sync it on their own in ->sync_fs(). | |
3beab0b4 | 90 | */ |
70f68ee8 | 91 | void ksys_sync(void) |
cf9a2ae8 | 92 | { |
b3de6531 JK |
93 | int nowait = 0, wait = 1; |
94 | ||
9ba4b2df | 95 | wakeup_flusher_threads(WB_REASON_SYNC); |
0dc83bd3 | 96 | iterate_supers(sync_inodes_one_sb, NULL); |
4ea425b6 | 97 | iterate_supers(sync_fs_one_sb, &nowait); |
b3de6531 | 98 | iterate_supers(sync_fs_one_sb, &wait); |
1e03a36b CH |
99 | sync_bdevs(false); |
100 | sync_bdevs(true); | |
cf9a2ae8 DH |
101 | if (unlikely(laptop_mode)) |
102 | laptop_sync_completion(); | |
70f68ee8 DB |
103 | } |
104 | ||
105 | SYSCALL_DEFINE0(sync) | |
106 | { | |
107 | ksys_sync(); | |
cf9a2ae8 DH |
108 | return 0; |
109 | } | |
110 | ||
a2a9537a JA |
111 | static void do_sync_work(struct work_struct *work) |
112 | { | |
b3de6531 JK |
113 | int nowait = 0; |
114 | ||
5cee5815 JK |
115 | /* |
116 | * Sync twice to reduce the possibility we skipped some inodes / pages | |
117 | * because they were temporarily locked | |
118 | */ | |
b3de6531 JK |
119 | iterate_supers(sync_inodes_one_sb, &nowait); |
120 | iterate_supers(sync_fs_one_sb, &nowait); | |
1e03a36b | 121 | sync_bdevs(false); |
b3de6531 JK |
122 | iterate_supers(sync_inodes_one_sb, &nowait); |
123 | iterate_supers(sync_fs_one_sb, &nowait); | |
1e03a36b | 124 | sync_bdevs(false); |
5cee5815 | 125 | printk("Emergency Sync complete\n"); |
a2a9537a JA |
126 | kfree(work); |
127 | } | |
128 | ||
cf9a2ae8 DH |
129 | void emergency_sync(void) |
130 | { | |
a2a9537a JA |
131 | struct work_struct *work; |
132 | ||
133 | work = kmalloc(sizeof(*work), GFP_ATOMIC); | |
134 | if (work) { | |
135 | INIT_WORK(work, do_sync_work); | |
136 | schedule_work(work); | |
137 | } | |
cf9a2ae8 DH |
138 | } |
139 | ||
b7ed78f5 SW |
140 | /* |
141 | * sync a single super | |
142 | */ | |
143 | SYSCALL_DEFINE1(syncfs, int, fd) | |
144 | { | |
2903ff01 | 145 | struct fd f = fdget(fd); |
b7ed78f5 | 146 | struct super_block *sb; |
735e4ae5 | 147 | int ret, ret2; |
b7ed78f5 | 148 | |
2903ff01 | 149 | if (!f.file) |
b7ed78f5 | 150 | return -EBADF; |
b583043e | 151 | sb = f.file->f_path.dentry->d_sb; |
b7ed78f5 SW |
152 | |
153 | down_read(&sb->s_umount); | |
154 | ret = sync_filesystem(sb); | |
155 | up_read(&sb->s_umount); | |
156 | ||
735e4ae5 JL |
157 | ret2 = errseq_check_and_advance(&sb->s_wb_err, &f.file->f_sb_err); |
158 | ||
2903ff01 | 159 | fdput(f); |
735e4ae5 | 160 | return ret ? ret : ret2; |
b7ed78f5 SW |
161 | } |
162 | ||
4c728ef5 | 163 | /** |
148f948b | 164 | * vfs_fsync_range - helper to sync a range of data & metadata to disk |
4c728ef5 | 165 | * @file: file to sync |
148f948b JK |
166 | * @start: offset in bytes of the beginning of data range to sync |
167 | * @end: offset in bytes of the end of data range (inclusive) | |
168 | * @datasync: perform only datasync | |
4c728ef5 | 169 | * |
148f948b JK |
170 | * Write back data in range @start..@end and metadata for @file to disk. If |
171 | * @datasync is set only metadata needed to access modified file data is | |
172 | * written. | |
4c728ef5 | 173 | */ |
8018ab05 | 174 | int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync) |
cf9a2ae8 | 175 | { |
0ae45f63 TT |
176 | struct inode *inode = file->f_mapping->host; |
177 | ||
72c2d531 | 178 | if (!file->f_op->fsync) |
02c24a82 | 179 | return -EINVAL; |
0d07e557 | 180 | if (!datasync && (inode->i_state & I_DIRTY_TIME)) |
0ae45f63 | 181 | mark_inode_dirty_sync(inode); |
0f41074a | 182 | return file->f_op->fsync(file, start, end, datasync); |
cf9a2ae8 | 183 | } |
148f948b JK |
184 | EXPORT_SYMBOL(vfs_fsync_range); |
185 | ||
186 | /** | |
187 | * vfs_fsync - perform a fsync or fdatasync on a file | |
188 | * @file: file to sync | |
148f948b JK |
189 | * @datasync: only perform a fdatasync operation |
190 | * | |
191 | * Write back data and metadata for @file to disk. If @datasync is | |
192 | * set only metadata needed to access modified file data is written. | |
148f948b | 193 | */ |
8018ab05 | 194 | int vfs_fsync(struct file *file, int datasync) |
148f948b | 195 | { |
8018ab05 | 196 | return vfs_fsync_range(file, 0, LLONG_MAX, datasync); |
148f948b | 197 | } |
4c728ef5 | 198 | EXPORT_SYMBOL(vfs_fsync); |
cf9a2ae8 | 199 | |
4c728ef5 | 200 | static int do_fsync(unsigned int fd, int datasync) |
cf9a2ae8 | 201 | { |
2903ff01 | 202 | struct fd f = fdget(fd); |
cf9a2ae8 DH |
203 | int ret = -EBADF; |
204 | ||
2903ff01 AV |
205 | if (f.file) { |
206 | ret = vfs_fsync(f.file, datasync); | |
207 | fdput(f); | |
cf9a2ae8 DH |
208 | } |
209 | return ret; | |
210 | } | |
211 | ||
a5f8fa9e | 212 | SYSCALL_DEFINE1(fsync, unsigned int, fd) |
cf9a2ae8 | 213 | { |
4c728ef5 | 214 | return do_fsync(fd, 0); |
cf9a2ae8 DH |
215 | } |
216 | ||
a5f8fa9e | 217 | SYSCALL_DEFINE1(fdatasync, unsigned int, fd) |
cf9a2ae8 | 218 | { |
4c728ef5 | 219 | return do_fsync(fd, 1); |
cf9a2ae8 DH |
220 | } |
221 | ||
22f96b38 JA |
222 | int sync_file_range(struct file *file, loff_t offset, loff_t nbytes, |
223 | unsigned int flags) | |
f79e2abb AM |
224 | { |
225 | int ret; | |
7a0ad10c | 226 | struct address_space *mapping; |
f79e2abb | 227 | loff_t endbyte; /* inclusive */ |
f79e2abb AM |
228 | umode_t i_mode; |
229 | ||
230 | ret = -EINVAL; | |
231 | if (flags & ~VALID_FLAGS) | |
232 | goto out; | |
233 | ||
234 | endbyte = offset + nbytes; | |
235 | ||
236 | if ((s64)offset < 0) | |
237 | goto out; | |
238 | if ((s64)endbyte < 0) | |
239 | goto out; | |
240 | if (endbyte < offset) | |
241 | goto out; | |
242 | ||
243 | if (sizeof(pgoff_t) == 4) { | |
09cbfeaf | 244 | if (offset >= (0x100000000ULL << PAGE_SHIFT)) { |
f79e2abb AM |
245 | /* |
246 | * The range starts outside a 32 bit machine's | |
247 | * pagecache addressing capabilities. Let it "succeed" | |
248 | */ | |
249 | ret = 0; | |
250 | goto out; | |
251 | } | |
09cbfeaf | 252 | if (endbyte >= (0x100000000ULL << PAGE_SHIFT)) { |
f79e2abb AM |
253 | /* |
254 | * Out to EOF | |
255 | */ | |
256 | nbytes = 0; | |
257 | } | |
258 | } | |
259 | ||
260 | if (nbytes == 0) | |
111ebb6e | 261 | endbyte = LLONG_MAX; |
f79e2abb AM |
262 | else |
263 | endbyte--; /* inclusive */ | |
264 | ||
22f96b38 | 265 | i_mode = file_inode(file)->i_mode; |
f79e2abb AM |
266 | ret = -ESPIPE; |
267 | if (!S_ISREG(i_mode) && !S_ISBLK(i_mode) && !S_ISDIR(i_mode) && | |
268 | !S_ISLNK(i_mode)) | |
22f96b38 | 269 | goto out; |
f79e2abb | 270 | |
22f96b38 | 271 | mapping = file->f_mapping; |
7a0ad10c CH |
272 | ret = 0; |
273 | if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) { | |
22f96b38 | 274 | ret = file_fdatawait_range(file, offset, endbyte); |
7a0ad10c | 275 | if (ret < 0) |
22f96b38 | 276 | goto out; |
7a0ad10c CH |
277 | } |
278 | ||
279 | if (flags & SYNC_FILE_RANGE_WRITE) { | |
c553ea4f AG |
280 | int sync_mode = WB_SYNC_NONE; |
281 | ||
282 | if ((flags & SYNC_FILE_RANGE_WRITE_AND_WAIT) == | |
283 | SYNC_FILE_RANGE_WRITE_AND_WAIT) | |
284 | sync_mode = WB_SYNC_ALL; | |
285 | ||
23d01270 | 286 | ret = __filemap_fdatawrite_range(mapping, offset, endbyte, |
c553ea4f | 287 | sync_mode); |
7a0ad10c | 288 | if (ret < 0) |
22f96b38 | 289 | goto out; |
7a0ad10c CH |
290 | } |
291 | ||
292 | if (flags & SYNC_FILE_RANGE_WAIT_AFTER) | |
22f96b38 | 293 | ret = file_fdatawait_range(file, offset, endbyte); |
7a0ad10c | 294 | |
f79e2abb AM |
295 | out: |
296 | return ret; | |
297 | } | |
298 | ||
22f96b38 | 299 | /* |
c553ea4f | 300 | * ksys_sync_file_range() permits finely controlled syncing over a segment of |
22f96b38 | 301 | * a file in the range offset .. (offset+nbytes-1) inclusive. If nbytes is |
c553ea4f | 302 | * zero then ksys_sync_file_range() will operate from offset out to EOF. |
22f96b38 JA |
303 | * |
304 | * The flag bits are: | |
305 | * | |
306 | * SYNC_FILE_RANGE_WAIT_BEFORE: wait upon writeout of all pages in the range | |
307 | * before performing the write. | |
308 | * | |
309 | * SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the | |
310 | * range which are not presently under writeback. Note that this may block for | |
311 | * significant periods due to exhaustion of disk request structures. | |
312 | * | |
313 | * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range | |
314 | * after performing the write. | |
315 | * | |
316 | * Useful combinations of the flag bits are: | |
317 | * | |
318 | * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE: ensures that all pages | |
c553ea4f | 319 | * in the range which were dirty on entry to ksys_sync_file_range() are placed |
22f96b38 JA |
320 | * under writeout. This is a start-write-for-data-integrity operation. |
321 | * | |
322 | * SYNC_FILE_RANGE_WRITE: start writeout of all dirty pages in the range which | |
323 | * are not presently under writeout. This is an asynchronous flush-to-disk | |
324 | * operation. Not suitable for data integrity operations. | |
325 | * | |
326 | * SYNC_FILE_RANGE_WAIT_BEFORE (or SYNC_FILE_RANGE_WAIT_AFTER): wait for | |
327 | * completion of writeout of all pages in the range. This will be used after an | |
328 | * earlier SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE operation to wait | |
329 | * for that operation to complete and to return the result. | |
330 | * | |
c553ea4f AG |
331 | * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE|SYNC_FILE_RANGE_WAIT_AFTER |
332 | * (a.k.a. SYNC_FILE_RANGE_WRITE_AND_WAIT): | |
22f96b38 JA |
333 | * a traditional sync() operation. This is a write-for-data-integrity operation |
334 | * which will ensure that all pages in the range which were dirty on entry to | |
c553ea4f AG |
335 | * ksys_sync_file_range() are written to disk. It should be noted that disk |
336 | * caches are not flushed by this call, so there are no guarantees here that the | |
337 | * data will be available on disk after a crash. | |
22f96b38 JA |
338 | * |
339 | * | |
340 | * SYNC_FILE_RANGE_WAIT_BEFORE and SYNC_FILE_RANGE_WAIT_AFTER will detect any | |
341 | * I/O errors or ENOSPC conditions and will return those to the caller, after | |
342 | * clearing the EIO and ENOSPC flags in the address_space. | |
343 | * | |
344 | * It should be noted that none of these operations write out the file's | |
345 | * metadata. So unless the application is strictly performing overwrites of | |
346 | * already-instantiated disk blocks, there are no guarantees here that the data | |
347 | * will be available after a crash. | |
348 | */ | |
349 | int ksys_sync_file_range(int fd, loff_t offset, loff_t nbytes, | |
350 | unsigned int flags) | |
351 | { | |
352 | int ret; | |
353 | struct fd f; | |
354 | ||
355 | ret = -EBADF; | |
356 | f = fdget(fd); | |
357 | if (f.file) | |
358 | ret = sync_file_range(f.file, offset, nbytes, flags); | |
359 | ||
360 | fdput(f); | |
361 | return ret; | |
362 | } | |
363 | ||
806cbae1 DB |
364 | SYSCALL_DEFINE4(sync_file_range, int, fd, loff_t, offset, loff_t, nbytes, |
365 | unsigned int, flags) | |
366 | { | |
367 | return ksys_sync_file_range(fd, offset, nbytes, flags); | |
368 | } | |
369 | ||
edd5cd4a DW |
370 | /* It would be nice if people remember that not all the world's an i386 |
371 | when they introduce new system calls */ | |
4a0fd5bf AV |
372 | SYSCALL_DEFINE4(sync_file_range2, int, fd, unsigned int, flags, |
373 | loff_t, offset, loff_t, nbytes) | |
edd5cd4a | 374 | { |
806cbae1 | 375 | return ksys_sync_file_range(fd, offset, nbytes, flags); |
edd5cd4a | 376 | } |