diff options
Diffstat (limited to 'fs/sync.c')
| -rw-r--r-- | fs/sync.c | 28 |
1 files changed, 3 insertions, 25 deletions
diff --git a/fs/sync.c b/fs/sync.c index ad6691bae370..f3f0a0e1948f 100644 --- a/fs/sync.c +++ b/fs/sync.c @@ -80,35 +80,15 @@ EXPORT_SYMBOL_GPL(sync_filesystem); /* * Sync all the data for all the filesystems (called by sys_sync() and * emergency sync) - * - * This operation is careful to avoid the livelock which could easily happen - * if two or more filesystems are being continuously dirtied. s_need_sync - * is used only here. We set it against all filesystems and then clear it as - * we sync them. So redirtied filesystems are skipped. - * - * But if process A is currently running sync_filesystems and then process B - * calls sync_filesystems as well, process B will set all the s_need_sync - * flags again, which will cause process A to resync everything. Fix that with - * a local mutex. */ static void sync_filesystems(int wait) { - struct super_block *sb; - static DEFINE_MUTEX(mutex); + struct super_block *sb, *n; - mutex_lock(&mutex); /* Could be down_interruptible */ spin_lock(&sb_lock); - list_for_each_entry(sb, &super_blocks, s_list) - if (!list_empty(&sb->s_instances)) - sb->s_need_sync = 1; - -restart: - list_for_each_entry(sb, &super_blocks, s_list) { + list_for_each_entry_safe(sb, n, &super_blocks, s_list) { if (list_empty(&sb->s_instances)) continue; - if (!sb->s_need_sync) - continue; - sb->s_need_sync = 0; sb->s_count++; spin_unlock(&sb_lock); @@ -119,11 +99,9 @@ restart: /* restart only when sb is no longer on the list */ spin_lock(&sb_lock); - if (__put_super_and_need_restart(sb)) - goto restart; + __put_super(sb); } spin_unlock(&sb_lock); - mutex_unlock(&mutex); } /* |