diff options
| author | Eric Sandeen <sandeen@redhat.com> | 2019-12-06 17:54:23 +0100 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2019-12-18 06:03:01 +0100 |
| commit | 04646aebd30b99f2cfa0182435a2ec252fcb16d0 (patch) | |
| tree | 5b820d440100bf1c9ce8db4be85d73ceb503cdca | |
| parent | pipe: Fix bogus dereference in iov_iter_alignment() (diff) | |
| download | linux-04646aebd30b99f2cfa0182435a2ec252fcb16d0.tar.xz linux-04646aebd30b99f2cfa0182435a2ec252fcb16d0.zip | |
fs: avoid softlockups in s_inodes iterators
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>
| -rw-r--r-- | fs/drop_caches.c | 2 | ||||
| -rw-r--r-- | fs/inode.c | 7 | ||||
| -rw-r--r-- | fs/notify/fsnotify.c | 1 | ||||
| -rw-r--r-- | fs/quota/dquot.c | 1 |
4 files changed, 10 insertions, 1 deletions
diff --git a/fs/drop_caches.c b/fs/drop_caches.c index d31b6c72b476..dc1a1d5d825b 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 fef457a42882..96d62d97694e 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -676,6 +676,7 @@ 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); @@ -698,6 +699,12 @@ 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 3e77b728a22b..6c902c0a1a5e 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -77,6 +77,7 @@ static 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 b0688c02dc90..b6a4f692d345 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -984,6 +984,7 @@ 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); |