From a9e220f8322e2b0e0b8903fe00265461cffad3f0 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 5 May 2009 22:10:44 -0400 Subject: [PATCH] No need to do lock_super() for exclusion in generic_shutdown_super() We can't run into contention on it. All other callers of lock_super() either hold s_umount (and we have it exclusive) or hold an active reference to superblock in question, which prevents the call of generic_shutdown_super() while the reference is held. So we can replace lock_super(s) with get_fs_excl() in generic_shutdown_super() (and corresponding change for unlock_super(), of course). Since ext4 expects s_lock held for its put_super, take lock_super() into it. The rest of filesystems do not care at all. Signed-off-by: Al Viro --- fs/ext4/super.c | 2 +- fs/super.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index c7b8f8d9b7a8..0d3034c5e8a4 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -576,6 +576,7 @@ static void ext4_put_super(struct super_block *sb) struct ext4_super_block *es = sbi->s_es; int i, err; + lock_super(sb); if (sb->s_dirt) ext4_write_super(sb); @@ -645,7 +646,6 @@ static void ext4_put_super(struct super_block *sb) unlock_super(sb); kobject_put(&sbi->s_kobj); wait_for_completion(&sbi->s_kobj_unregister); - lock_super(sb); lock_kernel(); kfree(sbi->s_blockgroup_lock); kfree(sbi); diff --git a/fs/super.c b/fs/super.c index 49f670cb9a83..54fd331f0cab 100644 --- a/fs/super.c +++ b/fs/super.c @@ -304,7 +304,7 @@ void generic_shutdown_super(struct super_block *sb) if (sb->s_root) { shrink_dcache_for_umount(sb); sync_filesystem(sb); - lock_super(sb); + get_fs_excl(); sb->s_flags &= ~MS_ACTIVE; /* bad name - it should be evict_inodes() */ @@ -322,7 +322,7 @@ void generic_shutdown_super(struct super_block *sb) } unlock_kernel(); - unlock_super(sb); + put_fs_excl(); } spin_lock(&sb_lock); /* should be initialized for __put_super_and_need_restart() */ -- 2.30.2