diff options
Diffstat (limited to 'fs/sync.c')
| -rw-r--r-- | fs/sync.c | 86 |
1 files changed, 67 insertions, 19 deletions
diff --git a/fs/sync.c b/fs/sync.c index 3422ba61d86..d104591b066 100644 --- a/fs/sync.c +++ b/fs/sync.c @@ -19,20 +19,29 @@ SYNC_FILE_RANGE_WAIT_AFTER) /* - * Do the filesystem syncing work. For simple filesystems sync_inodes_sb(sb, 0) - * just dirties buffers with inodes so we have to submit IO for these buffers - * via __sync_blockdev(). This also speeds up the wait == 1 case since in that - * case write_inode() functions do sync_dirty_buffer() and thus effectively - * write one block at a time. + * Do the filesystem syncing work. For simple filesystems + * writeback_inodes_sb(sb) just dirties buffers with inodes so we have to + * submit IO for these buffers via __sync_blockdev(). This also speeds up the + * wait == 1 case since in that case write_inode() functions do + * sync_dirty_buffer() and thus effectively write one block at a time. */ static int __sync_filesystem(struct super_block *sb, int wait) { + /* + * This should be safe, as we require bdi backing to actually + * write out data in the first place + */ + if (!sb->s_bdi) + return 0; + /* Avoid doing twice syncing and cache pruning for quota sync */ - if (!wait) + if (!wait) { writeout_quota_sb(sb, -1); - else + writeback_inodes_sb(sb); + } else { sync_quota_sb(sb, -1); - sync_inodes_sb(sb, wait); + sync_inodes_sb(sb); + } if (sb->s_op->sync_fs) sb->s_op->sync_fs(sb, wait); return __sync_blockdev(sb->s_bdev, wait); @@ -99,7 +108,7 @@ restart: spin_unlock(&sb_lock); down_read(&sb->s_umount); - if (!(sb->s_flags & MS_RDONLY) && sb->s_root) + if (!(sb->s_flags & MS_RDONLY) && sb->s_root && sb->s_bdi) __sync_filesystem(sb, wait); up_read(&sb->s_umount); @@ -118,7 +127,7 @@ restart: */ SYSCALL_DEFINE0(sync) { - wakeup_pdflush(0); + wakeup_flusher_threads(0); sync_filesystems(0); sync_filesystems(1); if (unlikely(laptop_mode)) @@ -174,21 +183,26 @@ int file_fsync(struct file *filp, struct dentry *dentry, int datasync) ret = err; return ret; } +EXPORT_SYMBOL(file_fsync); /** - * vfs_fsync - perform a fsync or fdatasync on a file + * vfs_fsync_range - helper to sync a range of data & metadata to disk * @file: file to sync * @dentry: dentry of @file - * @data: only perform a fdatasync operation + * @start: offset in bytes of the beginning of data range to sync + * @end: offset in bytes of the end of data range (inclusive) + * @datasync: perform only datasync * - * Write back data and metadata for @file to disk. If @datasync is - * set only metadata needed to access modified file data is written. + * Write back data in range @start..@end and metadata for @file to disk. If + * @datasync is set only metadata needed to access modified file data is + * written. * * In case this function is called from nfsd @file may be %NULL and * only @dentry is set. This can only happen when the filesystem * implements the export_operations API. */ -int vfs_fsync(struct file *file, struct dentry *dentry, int datasync) +int vfs_fsync_range(struct file *file, struct dentry *dentry, loff_t start, + loff_t end, int datasync) { const struct file_operations *fop; struct address_space *mapping; @@ -212,7 +226,7 @@ int vfs_fsync(struct file *file, struct dentry *dentry, int datasync) goto out; } - ret = filemap_fdatawrite(mapping); + ret = filemap_write_and_wait_range(mapping, start, end); /* * We need to protect against concurrent writers, which could cause @@ -223,12 +237,29 @@ int vfs_fsync(struct file *file, struct dentry *dentry, int datasync) if (!ret) ret = err; mutex_unlock(&mapping->host->i_mutex); - err = filemap_fdatawait(mapping); - if (!ret) - ret = err; + out: return ret; } +EXPORT_SYMBOL(vfs_fsync_range); + +/** + * vfs_fsync - perform a fsync or fdatasync on a file + * @file: file to sync + * @dentry: dentry of @file + * @datasync: only perform a fdatasync operation + * + * Write back data and metadata for @file to disk. If @datasync is + * set only metadata needed to access modified file data is written. + * + * In case this function is called from nfsd @file may be %NULL and + * only @dentry is set. This can only happen when the filesystem + * implements the export_operations API. + */ +int vfs_fsync(struct file *file, struct dentry *dentry, int datasync) +{ + return vfs_fsync_range(file, dentry, 0, LLONG_MAX, datasync); +} EXPORT_SYMBOL(vfs_fsync); static int do_fsync(unsigned int fd, int datasync) @@ -254,6 +285,23 @@ SYSCALL_DEFINE1(fdatasync, unsigned int, fd) return do_fsync(fd, 1); } +/** + * generic_write_sync - perform syncing after a write if file / inode is sync + * @file: file to which the write happened + * @pos: offset where the write started + * @count: length of the write + * + * This is just a simple wrapper about our general syncing function. + */ +int generic_write_sync(struct file *file, loff_t pos, loff_t count) +{ + if (!(file->f_flags & O_SYNC) && !IS_SYNC(file->f_mapping->host)) + return 0; + return vfs_fsync_range(file, file->f_path.dentry, pos, + pos + count - 1, 1); +} +EXPORT_SYMBOL(generic_write_sync); + /* * sys_sync_file_range() permits finely controlled syncing over a segment of * a file in the range offset .. (offset+nbytes-1) inclusive. If nbytes is |