From: Theodore Ts'o Subject: [PATCH 35/42] ext4: fix xattr deadlock Date: Thu, 9 Oct 2008 00:05:53 -0400 Message-ID: <1223525160-9887-36-git-send-email-tytso@mit.edu> References: <1223525160-9887-1-git-send-email-tytso@mit.edu> <1223525160-9887-2-git-send-email-tytso@mit.edu> <1223525160-9887-3-git-send-email-tytso@mit.edu> <1223525160-9887-4-git-send-email-tytso@mit.edu> <1223525160-9887-5-git-send-email-tytso@mit.edu> <1223525160-9887-6-git-send-email-tytso@mit.edu> <1223525160-9887-7-git-send-email-tytso@mit.edu> <1223525160-9887-8-git-send-email-tytso@mit.edu> <1223525160-9887-9-git-send-email-tytso@mit.edu> <1223525160-9887-10-git-send-email-tytso@mit.edu> <1223525160-9887-11-git-send-email-tytso@mit.edu> <1223525160-9887-12-git-send-email-tytso@mit.edu> <1223525160-9887-13-git-send-email-tytso@mit.edu> <1223525160-9887-14-git-send-email-tytso@mit.edu> <1223525160-9887-15-git-send-email-tytso@mit.edu> <1223525160-9887-16-git-send-email-tytso@mit.edu> <1223525160-9887-17-git-send-email-tytso@mit.edu> <1223525160-9887-18-git-send-email-tytso@mit.edu> <1223525160-9887-19-git-send-email-tytso@mit.edu> <1223525160-9887-20-git-send-email-tytso@mit.edu> <1223525160-9887-21-git-send-email-tytso@mit.edu> <1223525160-9887-22-git-send-email-tytso@mit.edu> <1223525160-9887-23-git-send-email-tytso@mit.edu> <1223525160-9887-24-git-send-email-tytso@mit.edu> <1223525160-9887-25-git-send-email-tytso@mit.edu> <1223525160-9887-26-git-send-email-tytso@mit.edu> <1223525160-9887-27-git-send-email-tytso@mit.edu> <1223525160-9887-28-git-send-email-tytso@mit.edu> <1223525160-9887-29-git-send-email-tytso@mit.edu> <1223525160-9887-30-git-send-email-tytso@mit.edu> <1223525160-9887-31-git-send-email-tytso@mit.edu> <1223525160-9887-32-git-send-email-tytso@mit.edu> <1223525160-9887-33-git-send-email-tytso@mit.edu> <1223525160-9887-34-git-send-email-tytso@mit.edu> <1223525160-9887-35-git-send-email-tytso@mit.edu> Cc: Kalpak Shah , "Theodore Ts'o" To: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Received: from www.church-of-our-saviour.org ([69.25.196.31]:54530 "EHLO thunker.thunk.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1757601AbYJIEGN (ORCPT ); Thu, 9 Oct 2008 00:06:13 -0400 In-Reply-To: <1223525160-9887-35-git-send-email-tytso@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: From: Kalpak Shah ext4_xattr_set_handle() eventually ends up calling ext4_mark_inode_dirty() which tries to expand the inode by shifting the EAs. This leads to the xattr_sem being downed again and leading to a deadlock. This patch makes sure that if ext4_xattr_set_handle() is in the call-chain, ext4_mark_inode_dirty() will not expand the inode. Signed-off-by: Kalpak Shah Signed-off-by: "Theodore Ts'o" --- fs/ext4/xattr.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 8954208..362b0ed 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -959,6 +959,7 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, struct ext4_xattr_block_find bs = { .s = { .not_found = -ENODATA, }, }; + unsigned long no_expand; int error; if (!name) @@ -966,6 +967,9 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, if (strlen(name) > 255) return -ERANGE; down_write(&EXT4_I(inode)->xattr_sem); + no_expand = EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND; + EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND; + error = ext4_get_inode_loc(inode, &is.iloc); if (error) goto cleanup; @@ -1042,6 +1046,8 @@ ext4_xattr_set_handle(handle_t *handle, struct inode *inode, int name_index, cleanup: brelse(is.iloc.bh); brelse(bs.bh); + if (no_expand == 0) + EXT4_I(inode)->i_state &= ~EXT4_STATE_NO_EXPAND; up_write(&EXT4_I(inode)->xattr_sem); return error; } -- 1.5.6.1.205.ge2c7.dirty