Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754264AbaDPETr (ORCPT ); Wed, 16 Apr 2014 00:19:47 -0400 Received: from cantor2.suse.de ([195.135.220.15]:38862 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754228AbaDPETo (ORCPT ); Wed, 16 Apr 2014 00:19:44 -0400 From: NeilBrown To: linux-mm@kvack.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 16 Apr 2014 14:03:37 +1000 Subject: [PATCH 16/19] VFS: use GFP_NOFS rather than GFP_KERNEL in __d_alloc. Cc: xfs@oss.sgi.com Message-ID: <20140416040337.10604.61837.stgit@notabene.brown> In-Reply-To: <20140416033623.10604.69237.stgit@notabene.brown> References: <20140416033623.10604.69237.stgit@notabene.brown> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org __d_alloc can be called with i_mutex held, so it is safer to use GFP_NOFS. lockdep reports this can deadlock when loop-back NFS is in use, as nfsd may be required to write out for reclaim, and nfsd certainly takes i_mutex. Signed-off-by: NeilBrown --- fs/dcache.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index ca02c13a84aa..3651ff6185b4 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1483,7 +1483,7 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) struct dentry *dentry; char *dname; - dentry = kmem_cache_alloc(dentry_cache, GFP_KERNEL); + dentry = kmem_cache_alloc(dentry_cache, GFP_NOFS); if (!dentry) return NULL; @@ -1495,7 +1495,7 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) */ dentry->d_iname[DNAME_INLINE_LEN-1] = 0; if (name->len > DNAME_INLINE_LEN-1) { - dname = kmalloc(name->len + 1, GFP_KERNEL); + dname = kmalloc(name->len + 1, GFP_NOFS); if (!dname) { kmem_cache_free(dentry_cache, dentry); return NULL; -- 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/