From: Eric Sandeen sandeen@redhat.com
[ Upstream commit 04646aebd30b99f2cfa0182435a2ec252fcb16d0 ]
Anything that walks all inodes on sb->s_inodes list without rescheduling risks softlockups.
Previous efforts were made in 2 functions, see:
c27d82f fs/drop_caches.c: avoid softlockups in drop_pagecache_sb() ac05fbb inode: don't softlockup when evicting inodes
but there hasn't been an audit of all walkers, so do that now. This also consistently moves the cond_resched() calls to the bottom of each loop in cases where it already exists.
One loop remains: remove_dquot_ref(), because I'm not quite sure how to deal with that one w/o taking the i_lock.
Signed-off-by: Eric Sandeen sandeen@redhat.com Reviewed-by: Jan Kara jack@suse.cz Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- fs/drop_caches.c | 2 +- fs/inode.c | 7 +++++++ fs/notify/fsnotify.c | 1 + fs/quota/dquot.c | 1 + 4 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/drop_caches.c b/fs/drop_caches.c index d31b6c7..dc1a1d5 100644 --- a/fs/drop_caches.c +++ b/fs/drop_caches.c @@ -35,11 +35,11 @@ static void drop_pagecache_sb(struct super_block *sb, void *unused) spin_unlock(&inode->i_lock); spin_unlock(&sb->s_inode_list_lock);
- cond_resched(); invalidate_mapping_pages(inode->i_mapping, 0, -1); iput(toput_inode); toput_inode = inode;
+ cond_resched(); spin_lock(&sb->s_inode_list_lock); } spin_unlock(&sb->s_inode_list_lock); diff --git a/fs/inode.c b/fs/inode.c index 5c63693..9c50521 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -660,6 +660,7 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty) struct inode *inode, *next; LIST_HEAD(dispose);
+again: spin_lock(&sb->s_inode_list_lock); list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { spin_lock(&inode->i_lock); @@ -682,6 +683,12 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty) inode_lru_list_del(inode); spin_unlock(&inode->i_lock); list_add(&inode->i_lru, &dispose); + if (need_resched()) { + spin_unlock(&sb->s_inode_list_lock); + cond_resched(); + dispose_list(&dispose); + goto again; + } } spin_unlock(&sb->s_inode_list_lock);
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 170a733..e8ee426 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -90,6 +90,7 @@ void fsnotify_unmount_inodes(struct super_block *sb)
iput_inode = inode;
+ cond_resched(); spin_lock(&sb->s_inode_list_lock); } spin_unlock(&sb->s_inode_list_lock); diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index 154f175..1d1d393 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -980,6 +980,7 @@ static int add_dquot_ref(struct super_block *sb, int type) * later. */ old_inode = inode; + cond_resched(); spin_lock(&sb->s_inode_list_lock); } spin_unlock(&sb->s_inode_list_lock);