diff options
author | Christoph Hellwig <hch@lst.de> | 2009-05-05 16:08:56 +0200 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2009-06-11 21:36:06 -0400 |
commit | e5004753388dcf5e1b8a52ac0ab807d232340fbb (patch) | |
tree | 4a74a93f1468acb111ba9a3e9ed4a55f338f51fe /fs/super.c | |
parent | f3da392e9ff14b9f388e74319e6d195848991c07 (diff) | |
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cleanup sync_supers
Merge the write_super helper into sync_super and move the check for
->write_super earlier so that we can avoid grabbing a reference to
a superblock that doesn't have it.
While we're at it also add a little comment documenting sync_supers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/super.c')
-rw-r--r-- | fs/super.c | 27 |
1 files changed, 15 insertions, 12 deletions
@@ -399,16 +399,14 @@ void drop_super(struct super_block *sb) EXPORT_SYMBOL(drop_super); -static inline void write_super(struct super_block *sb) -{ - lock_super(sb); - if (sb->s_root && sb->s_dirt) - if (sb->s_op->write_super) - sb->s_op->write_super(sb); - unlock_super(sb); -} - -/* +/** + * sync_supers - helper for periodic superblock writeback + * + * Call the write_super method if present on all dirty superblocks in + * the system. This is for the periodic writeback used by most older + * filesystems. For data integrity superblock writeback use + * sync_filesystems() instead. + * * Note: check the dirty flag before waiting, so we don't * hold up the sync while mounting a device. (The newly * mounted device won't need syncing.) @@ -420,12 +418,17 @@ void sync_supers(void) spin_lock(&sb_lock); restart: list_for_each_entry(sb, &super_blocks, s_list) { - if (sb->s_dirt) { + if (sb->s_op->write_super && sb->s_dirt) { sb->s_count++; spin_unlock(&sb_lock); + down_read(&sb->s_umount); - write_super(sb); + lock_super(sb); + if (sb->s_root && sb->s_dirt) + sb->s_op->write_super(sb); + unlock_super(sb); up_read(&sb->s_umount); + spin_lock(&sb_lock); if (__put_super_and_need_restart(sb)) goto restart; |