kpriv/linux-hardened
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

vfs: Reorder operations during sys_sync

Browse source 
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>
This commit is contained in:
Jan Kara 2012-07-03 16:45:30 +02:00 committed by Al Viro
parent a117782571
commit b3de653105
1 changed files with 34 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

46
fs/sync.c
View file

@ -67,18 +67,28 @@ int sync_filesystem(struct super_block *sb)
}
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 @@ static void sync_filesystems(int wait)
*/
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 @@ SYSCALL_DEFINE0(sync)
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);
}