From 551de6f34dfeefbeeadb32909c387d393114ecc8 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 22 Mar 2010 19:36:35 -0400 Subject: Leave superblocks on s_list until the end We used to remove from s_list and s_instances at the same time. So let's *not* do the former and skip superblocks that have empty s_instances in the loops over s_list. The next step, of course, will be to get rid of rescan logics in those loops. Signed-off-by: Al Viro --- fs/buffer.c | 2 ++ fs/dcache.c | 2 ++ fs/drop_caches.c | 2 ++ fs/quota/quota.c | 2 ++ fs/super.c | 16 +++++++++++++--- fs/sync.c | 5 ++++- 6 files changed, 25 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/buffer.c b/fs/buffer.c index c9c266db062..021ec4da993 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -568,6 +568,8 @@ static void do_thaw_all(struct work_struct *work) spin_lock(&sb_lock); restart: list_for_each_entry(sb, &super_blocks, s_list) { + if (list_empty(&sb->s_instances)) + continue; sb->s_count++; spin_unlock(&sb_lock); down_read(&sb->s_umount); diff --git a/fs/dcache.c b/fs/dcache.c index 2b6f09af13a..5afc4994bb2 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -552,6 +552,8 @@ restart: prune_ratio = unused / count; spin_lock(&sb_lock); list_for_each_entry(sb, &super_blocks, s_list) { + if (list_empty(&sb->s_instances)) + continue; if (sb->s_nr_dentry_unused == 0) continue; sb->s_count++; diff --git a/fs/drop_caches.c b/fs/drop_caches.c index 31f4b0e6d72..9cd4e4a70f5 100644 --- a/fs/drop_caches.c +++ b/fs/drop_caches.c @@ -40,6 +40,8 @@ static void drop_pagecache(void) spin_lock(&sb_lock); restart: list_for_each_entry(sb, &super_blocks, s_list) { + if (list_empty(&sb->s_instances)) + continue; sb->s_count++; spin_unlock(&sb_lock); down_read(&sb->s_umount); diff --git a/fs/quota/quota.c b/fs/quota/quota.c index cfc78826da9..4669e7e639b 100644 --- a/fs/quota/quota.c +++ b/fs/quota/quota.c @@ -59,6 +59,8 @@ static int quota_sync_all(int type) spin_lock(&sb_lock); restart: list_for_each_entry(sb, &super_blocks, s_list) { + if (list_empty(&sb->s_instances)) + continue; if (!sb->s_qcop || !sb->s_qcop->quota_sync) continue; diff --git a/fs/super.c b/fs/super.c index 157657b3279..0390461dfca 100644 --- a/fs/super.c +++ b/fs/super.c @@ -135,6 +135,7 @@ static int __put_super(struct super_block *sb) int ret = 0; if (!--sb->s_count) { + list_del_init(&sb->s_list); destroy_super(sb); ret = 1; } @@ -151,7 +152,7 @@ static int __put_super(struct super_block *sb) int __put_super_and_need_restart(struct super_block *sb) { /* check for race with generic_shutdown_super() */ - if (list_empty(&sb->s_list)) { + if (list_empty(&sb->s_instances)) { /* super block is removed, need to restart... */ __put_super(sb); return 1; @@ -308,8 +309,7 @@ void generic_shutdown_super(struct super_block *sb) } spin_lock(&sb_lock); /* should be initialized for __put_super_and_need_restart() */ - list_del_init(&sb->s_list); - list_del(&sb->s_instances); + list_del_init(&sb->s_instances); spin_unlock(&sb_lock); up_write(&sb->s_umount); } @@ -400,6 +400,8 @@ void sync_supers(void) spin_lock(&sb_lock); restart: list_for_each_entry(sb, &super_blocks, s_list) { + if (list_empty(&sb->s_instances)) + continue; if (sb->s_op->write_super && sb->s_dirt) { sb->s_count++; spin_unlock(&sb_lock); @@ -435,6 +437,8 @@ struct super_block * get_super(struct block_device *bdev) spin_lock(&sb_lock); rescan: list_for_each_entry(sb, &super_blocks, s_list) { + if (list_empty(&sb->s_instances)) + continue; if (sb->s_bdev == bdev) { sb->s_count++; spin_unlock(&sb_lock); @@ -471,6 +475,8 @@ struct super_block *get_active_super(struct block_device *bdev) spin_lock(&sb_lock); list_for_each_entry(sb, &super_blocks, s_list) { + if (list_empty(&sb->s_instances)) + continue; if (sb->s_bdev != bdev) continue; @@ -490,6 +496,8 @@ struct super_block * user_get_super(dev_t dev) spin_lock(&sb_lock); rescan: list_for_each_entry(sb, &super_blocks, s_list) { + if (list_empty(&sb->s_instances)) + continue; if (sb->s_dev == dev) { sb->s_count++; spin_unlock(&sb_lock); @@ -600,6 +608,8 @@ static void do_emergency_remount(struct work_struct *work) spin_lock(&sb_lock); list_for_each_entry(sb, &super_blocks, s_list) { + if (list_empty(&sb->s_instances)) + continue; sb->s_count++; spin_unlock(&sb_lock); down_write(&sb->s_umount); diff --git a/fs/sync.c b/fs/sync.c index 92b228176f7..ad6691bae37 100644 --- a/fs/sync.c +++ b/fs/sync.c @@ -99,10 +99,13 @@ static void sync_filesystems(int wait) mutex_lock(&mutex); /* Could be down_interruptible */ spin_lock(&sb_lock); list_for_each_entry(sb, &super_blocks, s_list) - sb->s_need_sync = 1; + if (!list_empty(&sb->s_instances)) + sb->s_need_sync = 1; restart: list_for_each_entry(sb, &super_blocks, s_list) { + if (list_empty(&sb->s_instances)) + continue; if (!sb->s_need_sync) continue; sb->s_need_sync = 0; -- cgit v1.2.3