blob: ac02b56548bcb4245da894568e3a175a2746e9f9 [file] [log] [blame]
Andrew Mortonf79e2ab2006-03-31 02:30:42 -08001/*
2 * High-level sync()-related operations
3 */
4
5#include <linux/kernel.h>
6#include <linux/file.h>
7#include <linux/fs.h>
8#include <linux/module.h>
Al Viro914e2632006-10-18 13:55:46 -04009#include <linux/sched.h>
Andrew Mortonf79e2ab2006-03-31 02:30:42 -080010#include <linux/writeback.h>
11#include <linux/syscalls.h>
12#include <linux/linkage.h>
13#include <linux/pagemap.h>
David Howellscf9a2ae2006-08-29 19:05:54 +010014#include <linux/quotaops.h>
15#include <linux/buffer_head.h>
Andrew Mortonf79e2ab2006-03-31 02:30:42 -080016
17#define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \
18 SYNC_FILE_RANGE_WAIT_AFTER)
19
20/*
David Howellscf9a2ae2006-08-29 19:05:54 +010021 * sync everything. Start out by waking pdflush, because that writes back
22 * all queues in parallel.
23 */
24static void do_sync(unsigned long wait)
25{
26 wakeup_pdflush(0);
27 sync_inodes(0); /* All mappings, inodes and their blockdevs */
28 DQUOT_SYNC(NULL);
29 sync_supers(); /* Write the superblocks */
30 sync_filesystems(0); /* Start syncing the filesystems */
31 sync_filesystems(wait); /* Waitingly sync the filesystems */
32 sync_inodes(wait); /* Mappings, inodes and blockdevs, again. */
33 if (!wait)
34 printk("Emergency Sync complete\n");
35 if (unlikely(laptop_mode))
36 laptop_sync_completion();
37}
38
39asmlinkage long sys_sync(void)
40{
41 do_sync(1);
42 return 0;
43}
44
45void emergency_sync(void)
46{
47 pdflush_operation(do_sync, 0);
48}
49
50/*
51 * Generic function to fsync a file.
52 *
53 * filp may be NULL if called via the msync of a vma.
54 */
55int file_fsync(struct file *filp, struct dentry *dentry, int datasync)
56{
57 struct inode * inode = dentry->d_inode;
58 struct super_block * sb;
59 int ret, err;
60
61 /* sync the inode to buffers */
62 ret = write_inode_now(inode, 0);
63
64 /* sync the superblock to buffers */
65 sb = inode->i_sb;
66 lock_super(sb);
OGAWA Hirofumi762873c2008-04-29 00:59:42 -070067 if (sb->s_dirt && sb->s_op->write_super)
David Howellscf9a2ae2006-08-29 19:05:54 +010068 sb->s_op->write_super(sb);
69 unlock_super(sb);
70
71 /* .. finally sync the buffers to disk */
72 err = sync_blockdev(sb->s_bdev);
73 if (!ret)
74 ret = err;
75 return ret;
76}
77
Christoph Hellwig4c728ef2008-12-22 21:11:15 +010078/**
79 * vfs_fsync - perform a fsync or fdatasync on a file
80 * @file: file to sync
81 * @dentry: dentry of @file
82 * @data: only perform a fdatasync operation
83 *
84 * Write back data and metadata for @file to disk. If @datasync is
85 * set only metadata needed to access modified file data is written.
86 *
87 * In case this function is called from nfsd @file may be %NULL and
88 * only @dentry is set. This can only happen when the filesystem
89 * implements the export_operations API.
90 */
91int vfs_fsync(struct file *file, struct dentry *dentry, int datasync)
David Howellscf9a2ae2006-08-29 19:05:54 +010092{
Christoph Hellwig4c728ef2008-12-22 21:11:15 +010093 const struct file_operations *fop;
94 struct address_space *mapping;
95 int err, ret;
David Howellscf9a2ae2006-08-29 19:05:54 +010096
Christoph Hellwig4c728ef2008-12-22 21:11:15 +010097 /*
98 * Get mapping and operations from the file in case we have
99 * as file, or get the default values for them in case we
100 * don't have a struct file available. Damn nfsd..
101 */
102 if (file) {
103 mapping = file->f_mapping;
104 fop = file->f_op;
105 } else {
106 mapping = dentry->d_inode->i_mapping;
107 fop = dentry->d_inode->i_fop;
108 }
109
110 if (!fop || !fop->fsync) {
David Howellscf9a2ae2006-08-29 19:05:54 +0100111 ret = -EINVAL;
112 goto out;
113 }
114
115 ret = filemap_fdatawrite(mapping);
116
117 /*
118 * We need to protect against concurrent writers, which could cause
119 * livelocks in fsync_buffers_list().
120 */
121 mutex_lock(&mapping->host->i_mutex);
Christoph Hellwig4c728ef2008-12-22 21:11:15 +0100122 err = fop->fsync(file, dentry, datasync);
David Howellscf9a2ae2006-08-29 19:05:54 +0100123 if (!ret)
124 ret = err;
125 mutex_unlock(&mapping->host->i_mutex);
126 err = filemap_fdatawait(mapping);
127 if (!ret)
128 ret = err;
129out:
130 return ret;
131}
Christoph Hellwig4c728ef2008-12-22 21:11:15 +0100132EXPORT_SYMBOL(vfs_fsync);
David Howellscf9a2ae2006-08-29 19:05:54 +0100133
Christoph Hellwig4c728ef2008-12-22 21:11:15 +0100134static int do_fsync(unsigned int fd, int datasync)
David Howellscf9a2ae2006-08-29 19:05:54 +0100135{
136 struct file *file;
137 int ret = -EBADF;
138
139 file = fget(fd);
140 if (file) {
Christoph Hellwig4c728ef2008-12-22 21:11:15 +0100141 ret = vfs_fsync(file, file->f_path.dentry, datasync);
David Howellscf9a2ae2006-08-29 19:05:54 +0100142 fput(file);
143 }
144 return ret;
145}
146
147asmlinkage long sys_fsync(unsigned int fd)
148{
Christoph Hellwig4c728ef2008-12-22 21:11:15 +0100149 return do_fsync(fd, 0);
David Howellscf9a2ae2006-08-29 19:05:54 +0100150}
151
152asmlinkage long sys_fdatasync(unsigned int fd)
153{
Christoph Hellwig4c728ef2008-12-22 21:11:15 +0100154 return do_fsync(fd, 1);
David Howellscf9a2ae2006-08-29 19:05:54 +0100155}
156
157/*
Andrew Mortonf79e2ab2006-03-31 02:30:42 -0800158 * sys_sync_file_range() permits finely controlled syncing over a segment of
159 * a file in the range offset .. (offset+nbytes-1) inclusive. If nbytes is
160 * zero then sys_sync_file_range() will operate from offset out to EOF.
161 *
162 * The flag bits are:
163 *
164 * SYNC_FILE_RANGE_WAIT_BEFORE: wait upon writeout of all pages in the range
165 * before performing the write.
166 *
167 * SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the
Pavel Machekcce77082008-07-23 21:27:36 -0700168 * range which are not presently under writeback. Note that this may block for
169 * significant periods due to exhaustion of disk request structures.
Andrew Mortonf79e2ab2006-03-31 02:30:42 -0800170 *
171 * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
172 * after performing the write.
173 *
174 * Useful combinations of the flag bits are:
175 *
176 * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE: ensures that all pages
177 * in the range which were dirty on entry to sys_sync_file_range() are placed
178 * under writeout. This is a start-write-for-data-integrity operation.
179 *
180 * SYNC_FILE_RANGE_WRITE: start writeout of all dirty pages in the range which
181 * are not presently under writeout. This is an asynchronous flush-to-disk
182 * operation. Not suitable for data integrity operations.
183 *
184 * SYNC_FILE_RANGE_WAIT_BEFORE (or SYNC_FILE_RANGE_WAIT_AFTER): wait for
185 * completion of writeout of all pages in the range. This will be used after an
186 * earlier SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE operation to wait
187 * for that operation to complete and to return the result.
188 *
189 * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE|SYNC_FILE_RANGE_WAIT_AFTER:
190 * a traditional sync() operation. This is a write-for-data-integrity operation
191 * which will ensure that all pages in the range which were dirty on entry to
192 * sys_sync_file_range() are committed to disk.
193 *
194 *
195 * SYNC_FILE_RANGE_WAIT_BEFORE and SYNC_FILE_RANGE_WAIT_AFTER will detect any
196 * I/O errors or ENOSPC conditions and will return those to the caller, after
197 * clearing the EIO and ENOSPC flags in the address_space.
198 *
199 * It should be noted that none of these operations write out the file's
200 * metadata. So unless the application is strictly performing overwrites of
201 * already-instantiated disk blocks, there are no guarantees here that the data
202 * will be available after a crash.
203 */
204asmlinkage long sys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
Andrew Morton5246d052006-04-10 22:53:57 -0700205 unsigned int flags)
Andrew Mortonf79e2ab2006-03-31 02:30:42 -0800206{
207 int ret;
208 struct file *file;
209 loff_t endbyte; /* inclusive */
210 int fput_needed;
211 umode_t i_mode;
212
213 ret = -EINVAL;
214 if (flags & ~VALID_FLAGS)
215 goto out;
216
217 endbyte = offset + nbytes;
218
219 if ((s64)offset < 0)
220 goto out;
221 if ((s64)endbyte < 0)
222 goto out;
223 if (endbyte < offset)
224 goto out;
225
226 if (sizeof(pgoff_t) == 4) {
227 if (offset >= (0x100000000ULL << PAGE_CACHE_SHIFT)) {
228 /*
229 * The range starts outside a 32 bit machine's
230 * pagecache addressing capabilities. Let it "succeed"
231 */
232 ret = 0;
233 goto out;
234 }
235 if (endbyte >= (0x100000000ULL << PAGE_CACHE_SHIFT)) {
236 /*
237 * Out to EOF
238 */
239 nbytes = 0;
240 }
241 }
242
243 if (nbytes == 0)
OGAWA Hirofumi111ebb62006-06-23 02:03:26 -0700244 endbyte = LLONG_MAX;
Andrew Mortonf79e2ab2006-03-31 02:30:42 -0800245 else
246 endbyte--; /* inclusive */
247
248 ret = -EBADF;
249 file = fget_light(fd, &fput_needed);
250 if (!file)
251 goto out;
252
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800253 i_mode = file->f_path.dentry->d_inode->i_mode;
Andrew Mortonf79e2ab2006-03-31 02:30:42 -0800254 ret = -ESPIPE;
255 if (!S_ISREG(i_mode) && !S_ISBLK(i_mode) && !S_ISDIR(i_mode) &&
256 !S_ISLNK(i_mode))
257 goto out_put;
258
Mark Fashehef51c972007-05-08 00:27:10 -0700259 ret = do_sync_mapping_range(file->f_mapping, offset, endbyte, flags);
Andrew Mortonf79e2ab2006-03-31 02:30:42 -0800260out_put:
261 fput_light(file, fput_needed);
262out:
263 return ret;
264}
265
David Woodhouseedd5cd42007-06-27 14:10:09 -0700266/* It would be nice if people remember that not all the world's an i386
267 when they introduce new system calls */
268asmlinkage long sys_sync_file_range2(int fd, unsigned int flags,
269 loff_t offset, loff_t nbytes)
270{
271 return sys_sync_file_range(fd, offset, nbytes, flags);
272}
273
Andrew Mortonf79e2ab2006-03-31 02:30:42 -0800274/*
275 * `endbyte' is inclusive
276 */
Mark Fasheh5b04aa32007-03-01 11:01:55 -0800277int do_sync_mapping_range(struct address_space *mapping, loff_t offset,
278 loff_t endbyte, unsigned int flags)
Andrew Mortonf79e2ab2006-03-31 02:30:42 -0800279{
280 int ret;
Andrew Mortonf79e2ab2006-03-31 02:30:42 -0800281
Andrew Mortonf79e2ab2006-03-31 02:30:42 -0800282 if (!mapping) {
283 ret = -EINVAL;
284 goto out;
285 }
286
287 ret = 0;
288 if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) {
289 ret = wait_on_page_writeback_range(mapping,
290 offset >> PAGE_CACHE_SHIFT,
291 endbyte >> PAGE_CACHE_SHIFT);
292 if (ret < 0)
293 goto out;
294 }
295
296 if (flags & SYNC_FILE_RANGE_WRITE) {
297 ret = __filemap_fdatawrite_range(mapping, offset, endbyte,
Nick Pigginee53a892009-01-06 14:39:12 -0800298 WB_SYNC_ALL);
Andrew Mortonf79e2ab2006-03-31 02:30:42 -0800299 if (ret < 0)
300 goto out;
301 }
302
303 if (flags & SYNC_FILE_RANGE_WAIT_AFTER) {
304 ret = wait_on_page_writeback_range(mapping,
305 offset >> PAGE_CACHE_SHIFT,
306 endbyte >> PAGE_CACHE_SHIFT);
307 }
308out:
309 return ret;
310}
Mark Fasheh5b04aa32007-03-01 11:01:55 -0800311EXPORT_SYMBOL_GPL(do_sync_mapping_range);