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authorJan Kara <jack@suse.cz>2009-04-27 16:43:51 +0200
committerAl Viro <viro@zeniv.linux.org.uk>2009-06-11 21:36:03 -0400
commit5cee5815d1564bbbd505fea86f4550f1efdb5cd0 (patch)
treeba99c38932dc534bf56f0d7dcfeeca153f50b007 /fs/sync.c
parent429479f031322a0cc5c921ffb2321a51718dc875 (diff)
vfs: Make sys_sync() use fsync_super() (version 4)
It is unnecessarily fragile to have two places (fsync_super() and do_sync()) doing data integrity sync of the filesystem. Alter __fsync_super() to accommodate needs of both callers and use it. So after this patch __fsync_super() is the only place where we gather all the calls needed to properly send all data on a filesystem to disk. Nice bonus is that we get a complete livelock avoidance and write_supers() is now only used for periodic writeback of superblocks. sync_blockdevs() introduced a couple of patches ago is gone now. [build fixes folded] Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/sync.c')
-rw-r--r--fs/sync.c31
1 files changed, 10 insertions, 21 deletions
diff --git a/fs/sync.c b/fs/sync.c
index 631fd5aece78..be0798cc33d7 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -18,35 +18,24 @@
#define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \
SYNC_FILE_RANGE_WAIT_AFTER)
-/*
- * sync everything. Start out by waking pdflush, because that writes back
- * all queues in parallel.
- */
-static void do_sync(unsigned long wait)
+SYSCALL_DEFINE0(sync)
{
- wakeup_pdflush(0);
- sync_inodes(0); /* All mappings, inodes and their blockdevs */
- vfs_dq_sync(NULL);
- sync_inodes(wait); /* Mappings, inodes and blockdevs, again. */
- sync_supers(); /* Write the superblocks */
- sync_filesystems(0); /* Start syncing the filesystems */
- sync_filesystems(wait); /* Waitingly sync the filesystems */
- sync_blockdevs();
- if (!wait)
- printk("Emergency Sync complete\n");
+ sync_filesystems(0);
+ sync_filesystems(1);
if (unlikely(laptop_mode))
laptop_sync_completion();
-}
-
-SYSCALL_DEFINE0(sync)
-{
- do_sync(1);
return 0;
}
static void do_sync_work(struct work_struct *work)
{
- do_sync(0);
+ /*
+ * Sync twice to reduce the possibility we skipped some inodes / pages
+ * because they were temporarily locked
+ */
+ sync_filesystems(0);
+ sync_filesystems(0);
+ printk("Emergency Sync complete\n");
kfree(work);
}