From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frederic Weisbecker Subject: [PATCH 2/4] kill-the-bkl/reiserfs: fix recursive reiserfs lock in reiserfs_mkdir() Date: Tue, 25 Aug 2009 04:32:48 +0200 Message-ID: <1251167570-5233-3-git-send-email-fweisbec@gmail.com> References: <1251167570-5233-1-git-send-email-fweisbec@gmail.com> Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:from:to:cc:subject:date :message-id:x-mailer:in-reply-to:references:to; bh=eyQFD0+vQV2CaL79PNy54x6fNuidtRQCMfMSTdxX3Do=; b=bnZpMwTMrBoiSIiSXl0sTKRpJXJULnr7dIWahhpwclw8LzgMp7YAX9Tzs9ThaspXAF ZmFsF+pyx/KdhZmRrtQFDb7aL4dinpzt43uNr6IKYvDVMKDR/R6jF4UhTqgbJETsDu6Q ruv2ZyUzVp5xYdSzjhUniQlvlsKDpevdHpv6s= In-Reply-To: <1251167570-5233-1-git-send-email-fweisbec@gmail.com> Sender: reiserfs-devel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: LKML Cc: LKML , Frederic Weisbecker , Chris Mason , Roland Dreier , Ingo Molnar , Andi Kleen , Jeff Mahoney , Alexander Beregalov , Bron Gondwana , Reiserfs , Al Viro , Andrea Gelmini , "Trenton D. Adams" , Thomas Meyer , Alessio Igor Bogani , Marcel Hilzinger , Edward Shishkin , Laurent Riffard reiserfs_mkdir() acquires the reiserfs lock, assuming it has been called from the dir inodes callbacks, without the lock held. But it can also be called from other internal sites such as reiserfs_xattr_init() which already holds the lock. This recursive locking leads to further wrong assumptions. For example, later calls to reiserfs_mutex_lock_safe() won't actually unlock the reiserfs lock the time we acquire a given mutex, creating unexpected lock inversions. Signed-off-by: Frederic Weisbecker Cc: Jeff Mahoney Cc: Chris Mason Cc: Ingo Molnar Cc: Alexander Beregalov Cc: Laurent Riffard --- fs/reiserfs/namei.c | 7 ++++--- 1 files changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/reiserfs/namei.c b/fs/reiserfs/namei.c index b3973c9..e296ff7 100644 --- a/fs/reiserfs/namei.c +++ b/fs/reiserfs/namei.c @@ -732,6 +732,7 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) struct inode *inode; struct reiserfs_transaction_handle th; struct reiserfs_security_handle security; + int lock_depth; /* We need blocks for transaction + (user+group)*(quotas for new inode + update of quota for directory owner) */ int jbegin_count = JOURNAL_PER_BALANCE_CNT * 3 + @@ -755,7 +756,7 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) return retval; } jbegin_count += retval; - reiserfs_write_lock(dir->i_sb); + lock_depth = reiserfs_write_lock_once(dir->i_sb); retval = journal_begin(&th, dir->i_sb, jbegin_count); if (retval) { @@ -805,8 +806,8 @@ static int reiserfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) d_instantiate(dentry, inode); unlock_new_inode(inode); retval = journal_end(&th, dir->i_sb, jbegin_count); - out_failed: - reiserfs_write_unlock(dir->i_sb); +out_failed: + reiserfs_write_unlock_once(dir->i_sb, lock_depth); return retval; } -- 1.6.2.3