1 // SPDX-License-Identifier: GPL-2.0
3  * High-level sync()-related operations
18 #include <linux/backing-dev.h>
25  * Write out and wait upon all dirty data associated with this
37 	WARN_ON(!rwsem_is_locked(&sb->s_umount));  in sync_filesystem()
40 	 * No point in syncing out anything if the filesystem is read-only.  in sync_filesystem()
49 	 * speeds up the wait == 1 case since in that case write_inode()  in sync_filesystem()
50 	 * methods call sync_dirty_buffer() and thus effectively write one block  in sync_filesystem()
54 	if (sb->s_op->sync_fs) {  in sync_filesystem()
55 		ret = sb->s_op->sync_fs(sb, 0);  in sync_filesystem()
59 	ret = __sync_blockdev(sb->s_bdev, 0);  in sync_filesystem()
64 	if (sb->s_op->sync_fs) {  in sync_filesystem()
65 		ret = sb->s_op->sync_fs(sb, 1);  in sync_filesystem()
69 	return __sync_blockdev(sb->s_bdev, 1);  in sync_filesystem()
81 	if (!sb_rdonly(sb) && !(sb->s_iflags & SB_I_SKIP_SYNC) &&  in sync_fs_one_sb()
82 	    sb->s_op->sync_fs)  in sync_fs_one_sb()
83 		sb->s_op->sync_fs(sb, *(int *)arg);  in sync_fs_one_sb()
88 	filemap_fdatawrite(bdev->bd_inode->i_mapping);  in fdatawrite_one_bdev()
98 	filemap_fdatawait_keep_errors(bdev->bd_inode->i_mapping);  in fdatawait_one_bdev()
103  * writeback runs on all devices in parallel. Then we sync all inodes reliably
105  * writeback. At this point all data is on disk so metadata should be stable
106  * and we tell filesystems to sync their metadata via ->sync_fs() calls.
108  * just write metadata (such as inodes or bitmaps) to block device page cache
109  * and do not sync it on their own in ->sync_fs().
113 	int nowait = 0, wait = 1;  in ksys_sync()  local
118 	iterate_supers(sync_fs_one_sb, &wait);  in ksys_sync()
170 		return -EBADF;  in SYSCALL_DEFINE1()
171 	sb = f.file->f_path.dentry->d_sb;  in SYSCALL_DEFINE1()
173 	down_read(&sb->s_umount);  in SYSCALL_DEFINE1()
175 	up_read(&sb->s_umount);  in SYSCALL_DEFINE1()
177 	ret2 = errseq_check_and_advance(&sb->s_wb_err, &f.file->f_sb_err);  in SYSCALL_DEFINE1()
184  * vfs_fsync_range - helper to sync a range of data & metadata to disk
190  * Write back data in range @start..@end and metadata for @file to disk.  If
196 	struct inode *inode = file->f_mapping->host;  in vfs_fsync_range()
198 	if (!file->f_op->fsync)  in vfs_fsync_range()
199 		return -EINVAL;  in vfs_fsync_range()
200 	if (!datasync && (inode->i_state & I_DIRTY_TIME))  in vfs_fsync_range()
202 	return file->f_op->fsync(file, start, end, datasync);  in vfs_fsync_range()
207  * vfs_fsync - perform a fsync or fdatasync on a file
211  * Write back data and metadata for @file to disk.  If @datasync is
223 	int ret = -EBADF;  in do_fsync()
250 	ret = -EINVAL;  in sync_file_range()
283 		endbyte--;		/* inclusive */  in sync_file_range()
285 	i_mode = file_inode(file)->i_mode;  in sync_file_range()
286 	ret = -ESPIPE;  in sync_file_range()
291 	mapping = file->f_mapping;  in sync_file_range()
321  * a file in the range offset .. (offset+nbytes-1) inclusive.  If nbytes is
326  * SYNC_FILE_RANGE_WAIT_BEFORE: wait upon writeout of all pages in the range
327  * before performing the write.
333  * SYNC_FILE_RANGE_WAIT_AFTER: wait upon writeout of all pages in the range
334  * after performing the write.
339  * in the range which were dirty on entry to ksys_sync_file_range() are placed
340  * under writeout.  This is a start-write-for-data-integrity operation.
343  * are not presently under writeout.  This is an asynchronous flush-to-disk
346  * SYNC_FILE_RANGE_WAIT_BEFORE (or SYNC_FILE_RANGE_WAIT_AFTER): wait for
348  * earlier SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE operation to wait
353  * a traditional sync() operation.  This is a write-for-data-integrity operation
354  * which will ensure that all pages in the range which were dirty on entry to
357  * data will be available on disk after a crash.
364  * It should be noted that none of these operations write out the file's
366  * already-instantiated disk blocks, there are no guarantees here that the data
375 	ret = -EBADF;  in ksys_sync_file_range()