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authorJan Kara <jack@suse.cz>2008-04-29 00:59:37 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-29 08:06:05 -0700
commiteccb95cee4f0d56faa46ef22fb94dd4a3578d3eb (patch)
tree45f2586854927cef529730ae0c7196d931de0c94 /fs
parenta8522509200b460443a7ca59138dc63bec1b690a (diff)
downloadlinux-eccb95cee4f0d56faa46ef22fb94dd4a3578d3eb.tar.gz
vfs: fix lock inversion in drop_pagecache_sb()
Fix longstanding lock inversion in drop_pagecache_sb by dropping inode_lock before calling __invalidate_mapping_pages(). We just have to make sure inode won't go away from under us by keeping reference to it and putting the reference only after we have safely resumed the scan of the inode list. A bit tricky but not too bad... Signed-off-by: Jan Kara <jack@suse.cz> Cc: Fengguang Wu <wfg@mail.ustc.edu.cn> Cc: David Chinner <dgc@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/drop_caches.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index e2c6b6500c7..50f9087635d 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -14,15 +14,21 @@ int sysctl_drop_caches;
static void drop_pagecache_sb(struct super_block *sb)
{
- struct inode *inode;
+ struct inode *inode, *toput_inode = NULL;
spin_lock(&inode_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
if (inode->i_state & (I_FREEING|I_WILL_FREE))
continue;
+ __iget(inode);
+ spin_unlock(&inode_lock);
__invalidate_mapping_pages(inode->i_mapping, 0, -1, true);
+ iput(toput_inode);
+ toput_inode = inode;
+ spin_lock(&inode_lock);
}
spin_unlock(&inode_lock);
+ iput(toput_inode);
}
static void drop_pagecache(void)