From a9e36da655e54545c3289b2a0700b5c443de0edd Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Wed, 21 Dec 2011 21:18:43 +0100 Subject: [PATCH] reiserfs: Force inode evictions before umount to avoid crash This patch fixes a crash in reiserfs_delete_xattrs during umount. When shrink_dcache_for_umount clears the dcache from generic_shutdown_super, delayed evictions are forced to disk. If an evicted inode has extended attributes associated with it, it will need to walk the xattr tree to locate and remove them. But since shrink_dcache_for_umount will BUG if it encounters active dentries, the xattr tree must be released before it's called or it will crash during every umount. This patch forces the evictions to occur before generic_shutdown_super by calling shrink_dcache_sb first. The additional evictions caused by the removal of each associated xattr file and dir will be automatically handled as they're added to the LRU list. CC: reiserfs-devel@vger.kernel.org CC: stable@kernel.org Signed-off-by: Jeff Mahoney Signed-off-by: Jan Kara --- fs/reiserfs/super.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c index f9eaa4a4f5f3..5e3527be1146 100644 --- a/fs/reiserfs/super.c +++ b/fs/reiserfs/super.c @@ -453,16 +453,20 @@ int remove_save_link(struct inode *inode, int truncate) static void reiserfs_kill_sb(struct super_block *s) { if (REISERFS_SB(s)) { - if (REISERFS_SB(s)->xattr_root) { - d_invalidate(REISERFS_SB(s)->xattr_root); - dput(REISERFS_SB(s)->xattr_root); - REISERFS_SB(s)->xattr_root = NULL; - } - if (REISERFS_SB(s)->priv_root) { - d_invalidate(REISERFS_SB(s)->priv_root); - dput(REISERFS_SB(s)->priv_root); - REISERFS_SB(s)->priv_root = NULL; - } + /* + * Force any pending inode evictions to occur now. Any + * inodes to be removed that have extended attributes + * associated with them need to clean them up before + * we can release the extended attribute root dentries. + * shrink_dcache_for_umount will BUG if we don't release + * those before it's called so ->put_super is too late. + */ + shrink_dcache_sb(s); + + dput(REISERFS_SB(s)->xattr_root); + REISERFS_SB(s)->xattr_root = NULL; + dput(REISERFS_SB(s)->priv_root); + REISERFS_SB(s)->priv_root = NULL; } kill_block_super(s);