vfs: Reorder operations during sys_sync
Change the order of operations during sync from
for_each_sb {
writeback_inodes_sb();
sync_fs(nowait);
__sync_blockdev(nowait);
}
for_each_sb {
sync_inodes_sb();
sync_fs(wait);
__sync_blockdev(wait);
}
to
for_each_sb
writeback_inodes_sb();
for_each_sb
sync_fs(nowait);
for_each_sb
__sync_blockdev(nowait);
for_each_sb
sync_inodes_sb();
for_each_sb
sync_fs(wait);
for_each_sb
__sync_blockdev(wait);
This is a preparation for the following patches in this series.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/sync.c b/fs/sync.c
index 66acd2b..490e902 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -67,18 +67,28 @@
}
EXPORT_SYMBOL_GPL(sync_filesystem);
-static void sync_one_sb(struct super_block *sb, void *arg)
+static void sync_inodes_one_sb(struct super_block *sb, void *arg)
{
if (!(sb->s_flags & MS_RDONLY))
- __sync_filesystem(sb, *(int *)arg);
+ sync_inodes_sb(sb);
}
-/*
- * Sync all the data for all the filesystems (called by sys_sync() and
- * emergency sync)
- */
-static void sync_filesystems(int wait)
+
+static void writeback_inodes_one_sb(struct super_block *sb, void *arg)
{
- iterate_supers(sync_one_sb, &wait);
+ 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)
+ sb->s_op->sync_fs(sb, *(int *)arg);
+}
+
+static void sync_blkdev_one_sb(struct super_block *sb, void *arg)
+{
+ if (!(sb->s_flags & MS_RDONLY))
+ __sync_blockdev(sb->s_bdev, *(int *)arg);
}
/*
@@ -87,9 +97,15 @@
*/
SYSCALL_DEFINE0(sync)
{
+ int nowait = 0, wait = 1;
+
wakeup_flusher_threads(0, WB_REASON_SYNC);
- sync_filesystems(0);
- sync_filesystems(1);
+ iterate_supers(writeback_inodes_one_sb, NULL);
+ iterate_supers(sync_fs_one_sb, &nowait);
+ iterate_supers(sync_blkdev_one_sb, &nowait);
+ iterate_supers(sync_inodes_one_sb, NULL);
+ iterate_supers(sync_fs_one_sb, &wait);
+ iterate_supers(sync_blkdev_one_sb, &wait);
if (unlikely(laptop_mode))
laptop_sync_completion();
return 0;
@@ -97,12 +113,18 @@
static void do_sync_work(struct work_struct *work)
{
+ int nowait = 0;
+
/*
* Sync twice to reduce the possibility we skipped some inodes / pages
* because they were temporarily locked
*/
- sync_filesystems(0);
- sync_filesystems(0);
+ iterate_supers(sync_inodes_one_sb, &nowait);
+ iterate_supers(sync_fs_one_sb, &nowait);
+ iterate_supers(sync_blkdev_one_sb, &nowait);
+ iterate_supers(sync_inodes_one_sb, &nowait);
+ iterate_supers(sync_fs_one_sb, &nowait);
+ iterate_supers(sync_blkdev_one_sb, &nowait);
printk("Emergency Sync complete\n");
kfree(work);
}