From b2f49033d80c952a0ffc2d5647bc1a0b8a09c1b3 Mon Sep 17 00:00:00 2001 From: Peter Staubach Date: Fri, 17 Feb 2006 13:52:36 -0800 Subject: [PATCH] fix deadlock in ext2 Fix a deadlock possible in the ext2 file system implementation. This deadlock occurs when a file is removed from an ext2 file system which was mounted with the "sync" mount option. The problem is that ext2_xattr_delete_inode() was invoking the routine, sync_dirty_buffer(), using a buffer head which was previously locked via lock_buffer(). The first thing that sync_dirty_buffer() does is to lock the buffer head that it was passed. It does this via lock_buffer(). Oops. The solution is to unlock the buffer head in ext2_xattr_delete_inode() before invoking sync_dirty_buffer(). This makes the code in ext2_xattr_delete_inode() obey the same locking rules as all other callers of sync_dirty_buffer() in the ext2 file system implementation. Signed-off-by: Peter Staubach Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ext2/xattr.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'fs/ext2') diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c index a2ca3107d475..86ae8e93adb9 100644 --- a/fs/ext2/xattr.c +++ b/fs/ext2/xattr.c @@ -792,18 +792,20 @@ ext2_xattr_delete_inode(struct inode *inode) ext2_free_blocks(inode, EXT2_I(inode)->i_file_acl, 1); get_bh(bh); bforget(bh); + unlock_buffer(bh); } else { HDR(bh)->h_refcount = cpu_to_le32( le32_to_cpu(HDR(bh)->h_refcount) - 1); if (ce) mb_cache_entry_release(ce); + ea_bdebug(bh, "refcount now=%d", + le32_to_cpu(HDR(bh)->h_refcount)); + unlock_buffer(bh); mark_buffer_dirty(bh); if (IS_SYNC(inode)) sync_dirty_buffer(bh); DQUOT_FREE_BLOCK(inode, 1); } - ea_bdebug(bh, "refcount now=%d", le32_to_cpu(HDR(bh)->h_refcount) - 1); - unlock_buffer(bh); EXT2_I(inode)->i_file_acl = 0; cleanup: -- cgit v1.2.1