Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753331Ab0K0K1C (ORCPT ); Sat, 27 Nov 2010 05:27:02 -0500 Received: from ipmail04.adl6.internode.on.net ([150.101.137.141]:26161 "EHLO ipmail04.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753139Ab0K0K0z (ORCPT ); Sat, 27 Nov 2010 05:26:55 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ApcFAO1p8Ex5Lcx2/2dsb2JhbACVC44Acr12hUcEimGFFA Message-Id: <45b8bcdbee5f379c471c819b3149b9d0df371113.1290852959.git.npiggin@kernel.dk> In-Reply-To: References: From: Nick Piggin Date: Sat, 27 Nov 2010 20:44:48 +1100 Subject: [PATCH 18/46] fs: increase d_name lock coverage To: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2121 Lines: 72 Cover d_name with d_lock in more cases, where there may be concurrent modification to it. Signed-off-by: Nick Piggin --- fs/dcache.c | 23 ++++++++++++++++------- 1 files changed, 16 insertions(+), 7 deletions(-) diff --git a/fs/dcache.c b/fs/dcache.c index 35420f7..7d0733b 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1361,16 +1361,20 @@ static struct dentry *__d_instantiate_unique(struct dentry *entry, list_for_each_entry(alias, &inode->i_dentry, d_alias) { struct qstr *qstr = &alias->d_name; + spin_lock(&alias->d_lock); if (qstr->hash != hash) - continue; + goto next; if (alias->d_parent != entry->d_parent) - continue; + goto next; if (qstr->len != len) - continue; + goto next; if (memcmp(qstr->name, name, len)) - continue; - dget_locked(alias); + goto next; + dget_locked_dlock(alias); + spin_unlock(&alias->d_lock); return alias; +next: + spin_unlock(&alias->d_lock); } __d_instantiate(entry, inode); @@ -2298,7 +2302,9 @@ static int prepend_path(const struct path *path, struct path *root, } parent = dentry->d_parent; prefetch(parent); + spin_lock(&dentry->d_lock); error = prepend_name(buffer, buflen, &dentry->d_name); + spin_unlock(&dentry->d_lock); if (!error) error = prepend(buffer, buflen, "/", 1); if (error) @@ -2506,10 +2512,13 @@ static char *__dentry_path(struct dentry *dentry, char *buf, int buflen) while (!IS_ROOT(dentry)) { struct dentry *parent = dentry->d_parent; + int error; prefetch(parent); - if ((prepend_name(&end, &buflen, &dentry->d_name) != 0) || - (prepend(&end, &buflen, "/", 1) != 0)) + spin_lock(&dentry->d_lock); + error = prepend_name(&end, &buflen, &dentry->d_name); + spin_unlock(&dentry->d_lock); + if (error != 0 || prepend(&end, &buflen, "/", 1) != 0) goto Elong; retval = end; -- 1.7.1 -- 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/