From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 12 Dec 2006 01:52:32 -0800 From: Andrew Morton Subject: Re: [PATCH] incorrect error handling inside generic_file_direct_write Message-Id: <20061212015232.eacfbb46.akpm@osdl.org> In-Reply-To: <87bqm9tie3.fsf@sw.ru> References: <87k60y1rq4.fsf@sw.ru> <20061211124052.144e69a0.akpm@osdl.org> <87bqm9tie3.fsf@sw.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Dmitriy Monakhov Cc: Dmitriy Monakhov , linux-kernel@vger.kernel.org, Linux Memory Management , devel@openvz.org, xfs@oss.sgi.com List-ID: On Tue, 12 Dec 2006 15:20:52 +0300 Dmitriy Monakhov wrote: > > XFS (at least) can call generic_file_direct_write() with i_mutex not held. > > And vmtruncate() expects i_mutex to be held. > > > > I guess a suitable solution would be to push this problem back up to the > > callers: let them decide whether to run vmtruncate() and if so, to ensure > > that i_mutex is held. > > > > The existence of generic_file_aio_write_nolock() makes that rather messy > > though. > This means we may call generic_file_aio_write_nolock() without i_mutex, right? > but call trace is : > generic_file_aio_write_nolock() > ->generic_file_buffered_write() /* i_mutex not held here */ > but according to filemaps locking rules: mm/filemap.c:77 > .. > * ->i_mutex (generic_file_buffered_write) > * ->mmap_sem (fault_in_pages_readable->do_page_fault) > .. > I'm confused a litle bit, where is the truth? xfs_write() calls generic_file_direct_write() without taking i_mutex for O_DIRECT writes. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org