diff options
| -rw-r--r-- | fs/sync.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/fs/sync.c b/fs/sync.c index 131ddae87a1d..eb8722dc556f 100644 --- a/fs/sync.c +++ b/fs/sync.c @@ -73,12 +73,6 @@ static void sync_inodes_one_sb(struct super_block *sb, void *arg) sync_inodes_sb(sb); } -static void writeback_inodes_one_sb(struct super_block *sb, void *arg) -{ - if (!(sb->s_flags & MS_RDONLY)) - writeback_inodes_sb(sb, WB_REASON_SYNC); -} - static void sync_fs_one_sb(struct super_block *sb, void *arg) { if (!(sb->s_flags & MS_RDONLY) && sb->s_op->sync_fs) @@ -96,17 +90,22 @@ static void fdatawait_one_bdev(struct block_device *bdev, void *arg) } /* - * sync everything. Start out by waking pdflush, because that writes back - * all queues in parallel. + * Sync everything. We start by waking flusher threads so that most of + * writeback runs on all devices in parallel. Then we sync all inodes reliably + * which effectively also waits for all flusher threads to finish doing + * writeback. At this point all data is on disk so metadata should be stable + * and we tell filesystems to sync their metadata via ->sync_fs() calls. + * Finally, we writeout all block devices because some filesystems (e.g. ext2) + * just write metadata (such as inodes or bitmaps) to block device page cache + * and do not sync it on their own in ->sync_fs(). */ SYSCALL_DEFINE0(sync) { int nowait = 0, wait = 1; wakeup_flusher_threads(0, WB_REASON_SYNC); - iterate_supers(writeback_inodes_one_sb, NULL); - iterate_supers(sync_fs_one_sb, &nowait); iterate_supers(sync_inodes_one_sb, NULL); + iterate_supers(sync_fs_one_sb, &nowait); iterate_supers(sync_fs_one_sb, &wait); iterate_bdevs(fdatawrite_one_bdev, NULL); iterate_bdevs(fdatawait_one_bdev, NULL); |