Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759907AbYHNSyz (ORCPT ); Thu, 14 Aug 2008 14:54:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752638AbYHNSyr (ORCPT ); Thu, 14 Aug 2008 14:54:47 -0400 Received: from smtprelay06.ispgateway.de ([80.67.18.44]:44356 "EHLO smtprelay06.ispgateway.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752178AbYHNSyr (ORCPT ); Thu, 14 Aug 2008 14:54:47 -0400 From: Ingo Oeser To: Jan Kara Subject: Re: [PATCH REVIEW] udf: Fix lock inversion between iprune_mutex and alloc_mutex Date: Thu, 14 Aug 2008 20:48:10 +0200 User-Agent: KMail/1.9.9 Cc: LKML References: <12187361983539-git-send-email-jack@suse.cz> In-Reply-To: <12187361983539-git-send-email-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200808142048.10966.ioe-lkml@rameria.de> X-Df-Sender: 849595 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2561 Lines: 75 Hi Jan, On Thursday 14 August 2008, Jan Kara wrote: > A memory allocation inside alloc_mutex must not recurse back > into the filesystem itself because that leads to lock inversion > between iprune_mutex and alloc_mutex (and thus to deadlocks - see > traces below). Make allocations inside alloc_mutex use GFP_NOFS > to avoid this problem. What about moving the allocation before taking the mutex? That way, we even reduce the lock contention and simplify the failure path. Signed-off-by: Ingo Oeser diff --git a/fs/udf/ialloc.c b/fs/udf/ialloc.c index eb9cfa2..76446eb 100644 --- a/fs/udf/ialloc.c +++ b/fs/udf/ialloc.c @@ -90,6 +90,25 @@ struct inode *udf_new_inode(struct inode *dir, int mode, int *err) return NULL; } + if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_EXTENDED_FE)) { + iinfo->i_efe = 1; + if (UDF_VERS_USE_EXTENDED_FE > sbi->s_udfrev) + sbi->s_udfrev = UDF_VERS_USE_EXTENDED_FE; + iinfo->i_ext.i_data = kzalloc(inode->i_sb->s_blocksize - + sizeof(struct extendedFileEntry), + GFP_KERNEL); + } else { + iinfo->i_efe = 0; + iinfo->i_ext.i_data = kzalloc(inode->i_sb->s_blocksize - + sizeof(struct fileEntry), + GFP_KERNEL); + } + if (!iinfo->i_ext.i_data) { + iput(inode); + *err = -ENOMEM; + return NULL; + } + mutex_lock(&sbi->s_alloc_mutex); if (sbi->s_lvid_bh) { struct logicalVolIntegrityDesc *lvid = @@ -129,25 +148,6 @@ struct inode *udf_new_inode(struct inode *dir, int mode, int *err) iinfo->i_lenEAttr = 0; iinfo->i_lenAlloc = 0; iinfo->i_use = 0; - if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_EXTENDED_FE)) { - iinfo->i_efe = 1; - if (UDF_VERS_USE_EXTENDED_FE > sbi->s_udfrev) - sbi->s_udfrev = UDF_VERS_USE_EXTENDED_FE; - iinfo->i_ext.i_data = kzalloc(inode->i_sb->s_blocksize - - sizeof(struct extendedFileEntry), - GFP_KERNEL); - } else { - iinfo->i_efe = 0; - iinfo->i_ext.i_data = kzalloc(inode->i_sb->s_blocksize - - sizeof(struct fileEntry), - GFP_KERNEL); - } - if (!iinfo->i_ext.i_data) { - iput(inode); - *err = -ENOMEM; - mutex_unlock(&sbi->s_alloc_mutex); - return NULL; - } if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_AD_IN_ICB)) iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB; else if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD)) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/