From: Ted Ts'o <tytso@mit.edu>
To: Jan Kara <jack@suse.cz>
Cc: linux-ext4@vger.kernel.org
Subject: Re: [PATCH 2/2] ext4: Fix deadlock in ext4_symlink() in ENOSPC conditions
Date: Tue, 3 May 2011 11:18:19 -0400 [thread overview]
Message-ID: <20110503151819.GD6462@thunk.org> (raw)
In-Reply-To: <1304112285-23477-1-git-send-email-jack@suse.cz>
On Fri, Apr 29, 2011 at 11:24:45PM +0200, Jan Kara wrote:
> ext4_symlink() cannot call __page_symlink() with transaction open.
> __page_symlink() calls ext4_write_begin() which can wait for
> transaction commit if we are running out of space thus causing a
> deadlock. Also error recovery in ext4_truncate_failed_write() does
> not count with the transaction being already started (although I'm
> not aware of any particular deadlock here).
>
> Fix the problem by stopping a transaction before calling __page_symlink()
> (we have to be careful and put inode to orphan list so that it gets deleted
> in case of crash) and starting another one after __page_symlink() returns
> for addition of symlink into a directory.
>
> Signed-off-by: Jan Kara <jack@suse.cz>
Thanks, added to the ext4 tree.
- Ted
prev parent reply other threads:[~2011-05-03 15:18 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-29 21:24 [PATCH 2/2] ext4: Fix deadlock in ext4_symlink() in ENOSPC conditions Jan Kara
2011-05-03 15:18 ` Ted Ts'o [this message]
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