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v4.17
  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * High-level sync()-related operations
  4 */
  5
  6#include <linux/kernel.h>
  7#include <linux/file.h>
  8#include <linux/fs.h>
  9#include <linux/slab.h>
 10#include <linux/export.h>
 11#include <linux/namei.h>
 12#include <linux/sched.h>
 13#include <linux/writeback.h>
 14#include <linux/syscalls.h>
 15#include <linux/linkage.h>
 16#include <linux/pagemap.h>
 17#include <linux/quotaops.h>
 18#include <linux/backing-dev.h>
 19#include "internal.h"
 20
 21#define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \
 22			SYNC_FILE_RANGE_WAIT_AFTER)
 23
 24/*
 25 * Do the filesystem syncing work. For simple filesystems
 26 * writeback_inodes_sb(sb) just dirties buffers with inodes so we have to
 27 * submit IO for these buffers via __sync_blockdev(). This also speeds up the
 28 * wait == 1 case since in that case write_inode() functions do
 29 * sync_dirty_buffer() and thus effectively write one block at a time.
 30 */
 31static int __sync_filesystem(struct super_block *sb, int wait)
 32{
 33	if (wait)
 34		sync_inodes_sb(sb);
 35	else
 36		writeback_inodes_sb(sb, WB_REASON_SYNC);
 37
 38	if (sb->s_op->sync_fs)
 39		sb->s_op->sync_fs(sb, wait);
 40	return __sync_blockdev(sb->s_bdev, wait);
 41}
 42
 43/*
 44 * Write out and wait upon all dirty data associated with this
 45 * superblock.  Filesystem data as well as the underlying block
 46 * device.  Takes the superblock lock.
 47 */
 48int sync_filesystem(struct super_block *sb)
 49{
 50	int ret;
 51
 52	/*
 53	 * We need to be protected against the filesystem going from
 54	 * r/o to r/w or vice versa.
 55	 */
 56	WARN_ON(!rwsem_is_locked(&sb->s_umount));
 57
 58	/*
 59	 * No point in syncing out anything if the filesystem is read-only.
 60	 */
 61	if (sb_rdonly(sb))
 62		return 0;
 63
 64	ret = __sync_filesystem(sb, 0);
 65	if (ret < 0)
 66		return ret;
 67	return __sync_filesystem(sb, 1);
 68}
 69EXPORT_SYMBOL(sync_filesystem);
 70
 71static void sync_inodes_one_sb(struct super_block *sb, void *arg)
 72{
 73	if (!sb_rdonly(sb))
 74		sync_inodes_sb(sb);
 75}
 76
 77static void sync_fs_one_sb(struct super_block *sb, void *arg)
 78{
 79	if (!sb_rdonly(sb) && sb->s_op->sync_fs)
 80		sb->s_op->sync_fs(sb, *(int *)arg);
 81}
 82
 83static void fdatawrite_one_bdev(struct block_device *bdev, void *arg)
 84{
 85	filemap_fdatawrite(bdev->bd_inode->i_mapping);
 86}
 87
 88static void fdatawait_one_bdev(struct block_device *bdev, void *arg)
 89{
 90	/*
 91	 * We keep the error status of individual mapping so that
 92	 * applications can catch the writeback error using fsync(2).
 93	 * See filemap_fdatawait_keep_errors() for details.
 94	 */
 95	filemap_fdatawait_keep_errors(bdev->bd_inode->i_mapping);
 96}
 97
 98/*
 99 * Sync everything. We start by waking flusher threads so that most of
100 * writeback runs on all devices in parallel. Then we sync all inodes reliably
101 * which effectively also waits for all flusher threads to finish doing
102 * writeback. At this point all data is on disk so metadata should be stable
103 * and we tell filesystems to sync their metadata via ->sync_fs() calls.
104 * Finally, we writeout all block devices because some filesystems (e.g. ext2)
105 * just write metadata (such as inodes or bitmaps) to block device page cache
106 * and do not sync it on their own in ->sync_fs().
107 */
108void ksys_sync(void)
109{
110	int nowait = 0, wait = 1;
111
112	wakeup_flusher_threads(WB_REASON_SYNC);
113	iterate_supers(sync_inodes_one_sb, NULL);
114	iterate_supers(sync_fs_one_sb, &nowait);
115	iterate_supers(sync_fs_one_sb, &wait);
116	iterate_bdevs(fdatawrite_one_bdev, NULL);
117	iterate_bdevs(fdatawait_one_bdev, NULL);
118	if (unlikely(laptop_mode))
119		laptop_sync_completion();
120}
121
122SYSCALL_DEFINE0(sync)
123{
124	ksys_sync();
125	return 0;
126}
127
128static void do_sync_work(struct work_struct *work)
129{
130	int nowait = 0;
131
132	/*
133	 * Sync twice to reduce the possibility we skipped some inodes / pages
134	 * because they were temporarily locked
135	 */
136	iterate_supers(sync_inodes_one_sb, &nowait);
137	iterate_supers(sync_fs_one_sb, &nowait);
138	iterate_bdevs(fdatawrite_one_bdev, NULL);
139	iterate_supers(sync_inodes_one_sb, &nowait);
140	iterate_supers(sync_fs_one_sb, &nowait);
141	iterate_bdevs(fdatawrite_one_bdev, NULL);
142	printk("Emergency Sync complete\n");
143	kfree(work);
144}
145
146void emergency_sync(void)
147{
148	struct work_struct *work;
149
150	work = kmalloc(sizeof(*work), GFP_ATOMIC);
151	if (work) {
152		INIT_WORK(work, do_sync_work);
153		schedule_work(work);
154	}
155}
156
157/*
158 * sync a single super
159 */
160SYSCALL_DEFINE1(syncfs, int, fd)
161{
162	struct fd f = fdget(fd);
163	struct super_block *sb;
164	int ret;
165
166	if (!f.file)
167		return -EBADF;
168	sb = f.file->f_path.dentry->d_sb;
169
170	down_read(&sb->s_umount);
171	ret = sync_filesystem(sb);
172	up_read(&sb->s_umount);
173
174	fdput(f);
175	return ret;
176}
177
178/**
179 * vfs_fsync_range - helper to sync a range of data & metadata to disk
180 * @file:		file to sync
181 * @start:		offset in bytes of the beginning of data range to sync
182 * @end:		offset in bytes of the end of data range (inclusive)
183 * @datasync:		perform only datasync
184 *
185 * Write back data in range @start..@end and metadata for @file to disk.  If
186 * @datasync is set only metadata needed to access modified file data is
187 * written.
188 */
189int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync)
190{
191	struct inode *inode = file->f_mapping->host;
192
193	if (!file->f_op->fsync)
194		return -EINVAL;
195	if (!datasync && (inode->i_state & I_DIRTY_TIME))
196		mark_inode_dirty_sync(inode);
197	return file->f_op->fsync(file, start, end, datasync);
198}
199EXPORT_SYMBOL(vfs_fsync_range);
200
201/**
202 * vfs_fsync - perform a fsync or fdatasync on a file
203 * @file:		file to sync
204 * @datasync:		only perform a fdatasync operation
205 *
206 * Write back data and metadata for @file to disk.  If @datasync is
207 * set only metadata needed to access modified file data is written.
208 */
209int vfs_fsync(struct file *file, int datasync)
210{
211	return vfs_fsync_range(file, 0, LLONG_MAX, datasync);
212}
213EXPORT_SYMBOL(vfs_fsync);
214
215static int do_fsync(unsigned int fd, int datasync)
216{
217	struct fd f = fdget(fd);
218	int ret = -EBADF;
219
220	if (f.file) {
221		ret = vfs_fsync(f.file, datasync);
222		fdput(f);
223	}
224	return ret;
225}
226
227SYSCALL_DEFINE1(fsync, unsigned int, fd)
228{
229	return do_fsync(fd, 0);
230}
231
232SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
233{
234	return do_fsync(fd, 1);
235}
236
237/*
238 * sys_sync_file_range() permits finely controlled syncing over a segment of
239 * a file in the range offset .. (offset+nbytes-1) inclusive.  If nbytes is
240 * zero then sys_sync_file_range() will operate from offset out to EOF.
241 *
242 * The flag bits are:
243 *
244 * SYNC_FILE_RANGE_WAIT_BEFORE: wait upon writeout of all pages in the range
245 * before performing the write.
246 *
247 * SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the
248 * range which are not presently under writeback. Note that this may block for
249 * significant periods due to exhaustion of disk request structures.
250 *
251 * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
252 * after performing the write.
253 *
254 * Useful combinations of the flag bits are:
255 *
256 * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE: ensures that all pages
257 * in the range which were dirty on entry to sys_sync_file_range() are placed
258 * under writeout.  This is a start-write-for-data-integrity operation.
259 *
260 * SYNC_FILE_RANGE_WRITE: start writeout of all dirty pages in the range which
261 * are not presently under writeout.  This is an asynchronous flush-to-disk
262 * operation.  Not suitable for data integrity operations.
263 *
264 * SYNC_FILE_RANGE_WAIT_BEFORE (or SYNC_FILE_RANGE_WAIT_AFTER): wait for
265 * completion of writeout of all pages in the range.  This will be used after an
266 * earlier SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE operation to wait
267 * for that operation to complete and to return the result.
268 *
269 * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE|SYNC_FILE_RANGE_WAIT_AFTER:
270 * a traditional sync() operation.  This is a write-for-data-integrity operation
271 * which will ensure that all pages in the range which were dirty on entry to
272 * sys_sync_file_range() are committed to disk.
273 *
274 *
275 * SYNC_FILE_RANGE_WAIT_BEFORE and SYNC_FILE_RANGE_WAIT_AFTER will detect any
276 * I/O errors or ENOSPC conditions and will return those to the caller, after
277 * clearing the EIO and ENOSPC flags in the address_space.
278 *
279 * It should be noted that none of these operations write out the file's
280 * metadata.  So unless the application is strictly performing overwrites of
281 * already-instantiated disk blocks, there are no guarantees here that the data
282 * will be available after a crash.
283 */
284int ksys_sync_file_range(int fd, loff_t offset, loff_t nbytes,
285			 unsigned int flags)
286{
287	int ret;
288	struct fd f;
289	struct address_space *mapping;
290	loff_t endbyte;			/* inclusive */
291	umode_t i_mode;
292
293	ret = -EINVAL;
294	if (flags & ~VALID_FLAGS)
295		goto out;
296
297	endbyte = offset + nbytes;
298
299	if ((s64)offset < 0)
300		goto out;
301	if ((s64)endbyte < 0)
302		goto out;
303	if (endbyte < offset)
304		goto out;
305
306	if (sizeof(pgoff_t) == 4) {
307		if (offset >= (0x100000000ULL << PAGE_SHIFT)) {
308			/*
309			 * The range starts outside a 32 bit machine's
310			 * pagecache addressing capabilities.  Let it "succeed"
311			 */
312			ret = 0;
313			goto out;
314		}
315		if (endbyte >= (0x100000000ULL << PAGE_SHIFT)) {
316			/*
317			 * Out to EOF
318			 */
319			nbytes = 0;
320		}
321	}
322
323	if (nbytes == 0)
324		endbyte = LLONG_MAX;
325	else
326		endbyte--;		/* inclusive */
327
328	ret = -EBADF;
329	f = fdget(fd);
330	if (!f.file)
331		goto out;
332
333	i_mode = file_inode(f.file)->i_mode;
334	ret = -ESPIPE;
335	if (!S_ISREG(i_mode) && !S_ISBLK(i_mode) && !S_ISDIR(i_mode) &&
336			!S_ISLNK(i_mode))
337		goto out_put;
338
339	mapping = f.file->f_mapping;
 
 
 
 
 
340	ret = 0;
341	if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) {
342		ret = file_fdatawait_range(f.file, offset, endbyte);
343		if (ret < 0)
344			goto out_put;
345	}
346
347	if (flags & SYNC_FILE_RANGE_WRITE) {
348		ret = __filemap_fdatawrite_range(mapping, offset, endbyte,
349						 WB_SYNC_NONE);
350		if (ret < 0)
351			goto out_put;
352	}
353
354	if (flags & SYNC_FILE_RANGE_WAIT_AFTER)
355		ret = file_fdatawait_range(f.file, offset, endbyte);
356
357out_put:
358	fdput(f);
359out:
360	return ret;
361}
362
363SYSCALL_DEFINE4(sync_file_range, int, fd, loff_t, offset, loff_t, nbytes,
364				unsigned int, flags)
365{
366	return ksys_sync_file_range(fd, offset, nbytes, flags);
367}
368
369/* It would be nice if people remember that not all the world's an i386
370   when they introduce new system calls */
371SYSCALL_DEFINE4(sync_file_range2, int, fd, unsigned int, flags,
372				 loff_t, offset, loff_t, nbytes)
373{
374	return ksys_sync_file_range(fd, offset, nbytes, flags);
375}
v3.15
 
  1/*
  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/slab.h>
  9#include <linux/export.h>
 10#include <linux/namei.h>
 11#include <linux/sched.h>
 12#include <linux/writeback.h>
 13#include <linux/syscalls.h>
 14#include <linux/linkage.h>
 15#include <linux/pagemap.h>
 16#include <linux/quotaops.h>
 17#include <linux/backing-dev.h>
 18#include "internal.h"
 19
 20#define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \
 21			SYNC_FILE_RANGE_WAIT_AFTER)
 22
 23/*
 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.
 29 */
 30static int __sync_filesystem(struct super_block *sb, int wait)
 31{
 32	if (wait)
 33		sync_inodes_sb(sb);
 34	else
 35		writeback_inodes_sb(sb, WB_REASON_SYNC);
 36
 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 */
 47int sync_filesystem(struct super_block *sb)
 48{
 49	int ret;
 50
 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
 63	ret = __sync_filesystem(sb, 0);
 64	if (ret < 0)
 65		return ret;
 66	return __sync_filesystem(sb, 1);
 67}
 68EXPORT_SYMBOL_GPL(sync_filesystem);
 69
 70static void sync_inodes_one_sb(struct super_block *sb, void *arg)
 71{
 72	if (!(sb->s_flags & MS_RDONLY))
 73		sync_inodes_sb(sb);
 74}
 75
 76static void sync_fs_one_sb(struct super_block *sb, void *arg)
 77{
 78	if (!(sb->s_flags & MS_RDONLY) && sb->s_op->sync_fs)
 79		sb->s_op->sync_fs(sb, *(int *)arg);
 80}
 81
 82static void fdatawrite_one_bdev(struct block_device *bdev, void *arg)
 83{
 84	filemap_fdatawrite(bdev->bd_inode->i_mapping);
 85}
 86
 87static void fdatawait_one_bdev(struct block_device *bdev, void *arg)
 88{
 89	filemap_fdatawait(bdev->bd_inode->i_mapping);
 
 
 
 
 
 90}
 91
 92/*
 93 * Sync everything. We start by waking flusher threads so that most of
 94 * writeback runs on all devices in parallel. Then we sync all inodes reliably
 95 * which effectively also waits for all flusher threads to finish doing
 96 * writeback. At this point all data is on disk so metadata should be stable
 97 * and we tell filesystems to sync their metadata via ->sync_fs() calls.
 98 * Finally, we writeout all block devices because some filesystems (e.g. ext2)
 99 * just write metadata (such as inodes or bitmaps) to block device page cache
100 * and do not sync it on their own in ->sync_fs().
101 */
102SYSCALL_DEFINE0(sync)
103{
104	int nowait = 0, wait = 1;
105
106	wakeup_flusher_threads(0, WB_REASON_SYNC);
107	iterate_supers(sync_inodes_one_sb, NULL);
108	iterate_supers(sync_fs_one_sb, &nowait);
109	iterate_supers(sync_fs_one_sb, &wait);
110	iterate_bdevs(fdatawrite_one_bdev, NULL);
111	iterate_bdevs(fdatawait_one_bdev, NULL);
112	if (unlikely(laptop_mode))
113		laptop_sync_completion();
 
 
 
 
 
114	return 0;
115}
116
117static void do_sync_work(struct work_struct *work)
118{
119	int nowait = 0;
120
121	/*
122	 * Sync twice to reduce the possibility we skipped some inodes / pages
123	 * because they were temporarily locked
124	 */
125	iterate_supers(sync_inodes_one_sb, &nowait);
126	iterate_supers(sync_fs_one_sb, &nowait);
127	iterate_bdevs(fdatawrite_one_bdev, NULL);
128	iterate_supers(sync_inodes_one_sb, &nowait);
129	iterate_supers(sync_fs_one_sb, &nowait);
130	iterate_bdevs(fdatawrite_one_bdev, NULL);
131	printk("Emergency Sync complete\n");
132	kfree(work);
133}
134
135void emergency_sync(void)
136{
137	struct work_struct *work;
138
139	work = kmalloc(sizeof(*work), GFP_ATOMIC);
140	if (work) {
141		INIT_WORK(work, do_sync_work);
142		schedule_work(work);
143	}
144}
145
146/*
147 * sync a single super
148 */
149SYSCALL_DEFINE1(syncfs, int, fd)
150{
151	struct fd f = fdget(fd);
152	struct super_block *sb;
153	int ret;
154
155	if (!f.file)
156		return -EBADF;
157	sb = f.file->f_dentry->d_sb;
158
159	down_read(&sb->s_umount);
160	ret = sync_filesystem(sb);
161	up_read(&sb->s_umount);
162
163	fdput(f);
164	return ret;
165}
166
167/**
168 * vfs_fsync_range - helper to sync a range of data & metadata to disk
169 * @file:		file to sync
170 * @start:		offset in bytes of the beginning of data range to sync
171 * @end:		offset in bytes of the end of data range (inclusive)
172 * @datasync:		perform only datasync
173 *
174 * Write back data in range @start..@end and metadata for @file to disk.  If
175 * @datasync is set only metadata needed to access modified file data is
176 * written.
177 */
178int vfs_fsync_range(struct file *file, loff_t start, loff_t end, int datasync)
179{
 
 
180	if (!file->f_op->fsync)
181		return -EINVAL;
 
 
182	return file->f_op->fsync(file, start, end, datasync);
183}
184EXPORT_SYMBOL(vfs_fsync_range);
185
186/**
187 * vfs_fsync - perform a fsync or fdatasync on a file
188 * @file:		file to sync
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.
193 */
194int vfs_fsync(struct file *file, int datasync)
195{
196	return vfs_fsync_range(file, 0, LLONG_MAX, datasync);
197}
198EXPORT_SYMBOL(vfs_fsync);
199
200static int do_fsync(unsigned int fd, int datasync)
201{
202	struct fd f = fdget(fd);
203	int ret = -EBADF;
204
205	if (f.file) {
206		ret = vfs_fsync(f.file, datasync);
207		fdput(f);
208	}
209	return ret;
210}
211
212SYSCALL_DEFINE1(fsync, unsigned int, fd)
213{
214	return do_fsync(fd, 0);
215}
216
217SYSCALL_DEFINE1(fdatasync, unsigned int, fd)
218{
219	return do_fsync(fd, 1);
220}
221
222/*
223 * sys_sync_file_range() permits finely controlled syncing over a segment of
224 * a file in the range offset .. (offset+nbytes-1) inclusive.  If nbytes is
225 * zero then sys_sync_file_range() will operate from offset out to EOF.
226 *
227 * The flag bits are:
228 *
229 * SYNC_FILE_RANGE_WAIT_BEFORE: wait upon writeout of all pages in the range
230 * before performing the write.
231 *
232 * SYNC_FILE_RANGE_WRITE: initiate writeout of all those dirty pages in the
233 * range which are not presently under writeback. Note that this may block for
234 * significant periods due to exhaustion of disk request structures.
235 *
236 * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
237 * after performing the write.
238 *
239 * Useful combinations of the flag bits are:
240 *
241 * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE: ensures that all pages
242 * in the range which were dirty on entry to sys_sync_file_range() are placed
243 * under writeout.  This is a start-write-for-data-integrity operation.
244 *
245 * SYNC_FILE_RANGE_WRITE: start writeout of all dirty pages in the range which
246 * are not presently under writeout.  This is an asynchronous flush-to-disk
247 * operation.  Not suitable for data integrity operations.
248 *
249 * SYNC_FILE_RANGE_WAIT_BEFORE (or SYNC_FILE_RANGE_WAIT_AFTER): wait for
250 * completion of writeout of all pages in the range.  This will be used after an
251 * earlier SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE operation to wait
252 * for that operation to complete and to return the result.
253 *
254 * SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE|SYNC_FILE_RANGE_WAIT_AFTER:
255 * a traditional sync() operation.  This is a write-for-data-integrity operation
256 * which will ensure that all pages in the range which were dirty on entry to
257 * sys_sync_file_range() are committed to disk.
258 *
259 *
260 * SYNC_FILE_RANGE_WAIT_BEFORE and SYNC_FILE_RANGE_WAIT_AFTER will detect any
261 * I/O errors or ENOSPC conditions and will return those to the caller, after
262 * clearing the EIO and ENOSPC flags in the address_space.
263 *
264 * It should be noted that none of these operations write out the file's
265 * metadata.  So unless the application is strictly performing overwrites of
266 * already-instantiated disk blocks, there are no guarantees here that the data
267 * will be available after a crash.
268 */
269SYSCALL_DEFINE4(sync_file_range, int, fd, loff_t, offset, loff_t, nbytes,
270				unsigned int, flags)
271{
272	int ret;
273	struct fd f;
274	struct address_space *mapping;
275	loff_t endbyte;			/* inclusive */
276	umode_t i_mode;
277
278	ret = -EINVAL;
279	if (flags & ~VALID_FLAGS)
280		goto out;
281
282	endbyte = offset + nbytes;
283
284	if ((s64)offset < 0)
285		goto out;
286	if ((s64)endbyte < 0)
287		goto out;
288	if (endbyte < offset)
289		goto out;
290
291	if (sizeof(pgoff_t) == 4) {
292		if (offset >= (0x100000000ULL << PAGE_CACHE_SHIFT)) {
293			/*
294			 * The range starts outside a 32 bit machine's
295			 * pagecache addressing capabilities.  Let it "succeed"
296			 */
297			ret = 0;
298			goto out;
299		}
300		if (endbyte >= (0x100000000ULL << PAGE_CACHE_SHIFT)) {
301			/*
302			 * Out to EOF
303			 */
304			nbytes = 0;
305		}
306	}
307
308	if (nbytes == 0)
309		endbyte = LLONG_MAX;
310	else
311		endbyte--;		/* inclusive */
312
313	ret = -EBADF;
314	f = fdget(fd);
315	if (!f.file)
316		goto out;
317
318	i_mode = file_inode(f.file)->i_mode;
319	ret = -ESPIPE;
320	if (!S_ISREG(i_mode) && !S_ISBLK(i_mode) && !S_ISDIR(i_mode) &&
321			!S_ISLNK(i_mode))
322		goto out_put;
323
324	mapping = f.file->f_mapping;
325	if (!mapping) {
326		ret = -EINVAL;
327		goto out_put;
328	}
329
330	ret = 0;
331	if (flags & SYNC_FILE_RANGE_WAIT_BEFORE) {
332		ret = filemap_fdatawait_range(mapping, offset, endbyte);
333		if (ret < 0)
334			goto out_put;
335	}
336
337	if (flags & SYNC_FILE_RANGE_WRITE) {
338		ret = filemap_fdatawrite_range(mapping, offset, endbyte);
 
339		if (ret < 0)
340			goto out_put;
341	}
342
343	if (flags & SYNC_FILE_RANGE_WAIT_AFTER)
344		ret = filemap_fdatawait_range(mapping, offset, endbyte);
345
346out_put:
347	fdput(f);
348out:
349	return ret;
350}
351
 
 
 
 
 
 
352/* It would be nice if people remember that not all the world's an i386
353   when they introduce new system calls */
354SYSCALL_DEFINE4(sync_file_range2, int, fd, unsigned int, flags,
355				 loff_t, offset, loff_t, nbytes)
356{
357	return sys_sync_file_range(fd, offset, nbytes, flags);
358}