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From: Jan Blunck <jblunck@suse.de>
To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: viro@zeniv.linux.org.uk, bharata@in.ibm.com, dwmw2@infradead.org,
	mszeredi@suse.cz, vaurora@redhat.com
Subject: [PATCH 05/32] VFS: Remove unnecessary micro-optimization in cached_lookup()
Date: Mon, 18 May 2009 18:09:01 +0200	[thread overview]
Message-ID: <1242662968-11684-6-git-send-email-jblunck@suse.de> (raw)
In-Reply-To: <1242662968-11684-1-git-send-email-jblunck@suse.de>

d_lookup() takes rename_lock which is a seq_lock.  This is so cheap
it's not worth calling lockless __d_lookup() first from
cache_lookup().  Rename cached_lookup() to cache_lookup() while we're
there.

Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Valerie Aurora (Henson) <vaurora@redhat.com>
---
 fs/namei.c |   13 ++++---------
 1 files changed, 4 insertions(+), 9 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 081aef1..a9dd19b 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -402,15 +402,10 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd)
  * Internal lookup() using the new generic dcache.
  * SMP-safe
  */
-static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name, struct nameidata *nd)
+static struct dentry *cache_lookup(struct dentry *parent, struct qstr *name,
+				   struct nameidata *nd)
 {
-	struct dentry * dentry = __d_lookup(parent, name);
-
-	/* lockess __d_lookup may fail due to concurrent d_move() 
-	 * in some unrelated directory, so try with d_lookup
-	 */
-	if (!dentry)
-		dentry = d_lookup(parent, name);
+	struct dentry *dentry = d_lookup(parent, name);
 
 	if (dentry && dentry->d_op && dentry->d_op->d_revalidate)
 		dentry = do_revalidate(dentry, nd);
@@ -1168,7 +1163,7 @@ static struct dentry *__lookup_hash(struct qstr *name,
 			goto out;
 	}
 
-	dentry = cached_lookup(base, name, nd);
+	dentry = cache_lookup(base, name, nd);
 	if (!dentry) {
 		struct dentry *new;
 
-- 
1.6.1.3


  parent reply	other threads:[~2009-05-18 16:09 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-18 16:08 [PATCH 00/32] VFS based Union Mount (V3) Jan Blunck
2009-05-18 16:08 ` [PATCH 01/32] atomic: Only take lock when the counter drops to zero on UP as well Jan Blunck
2009-05-18 16:08 ` [PATCH 02/32] VFS: BUG() if somebody tries to rehash an already hashed dentry Jan Blunck
2009-05-18 16:08 ` [PATCH 03/32] VFS: propagate mnt_flags into do_loopback Jan Blunck
2009-05-18 16:09 ` [PATCH 04/32] VFS: Make lookup_hash() return a struct path Jan Blunck
2009-05-18 16:09 ` Jan Blunck [this message]
2009-05-18 16:09 ` [PATCH 06/32] VFS: Make real_lookup() " Jan Blunck
2009-05-18 16:09 ` [PATCH 07/32] VFS: Introduce dput() variant that maintains a kill-list Jan Blunck
2009-05-18 16:09 ` [PATCH 08/32] whiteout: Don't return information about whiteouts to userspace Jan Blunck
2009-05-18 16:09 ` [PATCH 09/32] whiteout: Add vfs_whiteout() and whiteout inode operation Jan Blunck
2009-05-18 16:09 ` [PATCH 10/32] whiteout: Set S_OPAQUE inode flag when creating directories Jan Blunck
2009-05-18 16:09 ` [PATCH 11/32] whiteout: Add whiteout support to tmpfs Jan Blunck
2009-05-18 16:09 ` [PATCH 12/32] whiteout: Split of ext2_append_link() from ext2_add_link() Jan Blunck
2009-05-18 16:09 ` [PATCH 13/32] whiteout: Add whiteout support to ext2 Jan Blunck
2009-05-18 16:09 ` [PATCH 14/32] whiteout: Add path_whiteout() helper Jan Blunck
2009-05-18 16:09 ` [PATCH 15/32] union-mount: Documentation Jan Blunck
2009-05-25  6:25   ` hooanon05
2009-05-25  8:03     ` Arnd Bergmann
2009-05-25  8:43       ` hooanon05
2009-06-18 19:05         ` Valerie Aurora
2009-06-19  1:53           ` hooanon05
2009-05-18 16:09 ` [PATCH 16/32] union-mount: Introduce MNT_UNION and MS_UNION flags Jan Blunck
2009-05-18 16:09 ` [PATCH 17/32] union-mount: Introduce union_mount structure Jan Blunck
2009-05-18 16:09 ` [PATCH 18/32] union-mount: Drive the union cache via dcache Jan Blunck
2009-05-18 16:09 ` [PATCH 19/32] union-mount: Some checks during namespace changes Jan Blunck
2009-05-18 16:09 ` [PATCH 20/32] union-mount: Changes to the namespace handling Jan Blunck
2009-05-18 16:09 ` [PATCH 21/32] union-mount: Make lookup work for union-mounted file systems Jan Blunck
2009-05-19 16:15   ` Miklos Szeredi
2009-05-19 17:30     ` Valerie Aurora
2009-05-20 10:21       ` Miklos Szeredi
2009-05-18 16:09 ` [PATCH 22/32] union-mount: stop lookup when directory has S_OPAQUE flag set Jan Blunck
2009-05-18 16:09 ` [PATCH 23/32] union-mount: stop lookup when finding a whiteout Jan Blunck
2009-05-18 16:09 ` [PATCH 24/32] union-mount: in-kernel file copy between union mounted filesystems Jan Blunck
2009-05-18 16:09 ` [PATCH 25/32] union-mount: check for logically empty directory (FIXME) Jan Blunck
2009-05-18 16:09 ` [PATCH 26/32] union-mount: call do_whiteout() on unlink and rmdir Jan Blunck
2009-05-18 16:09 ` [PATCH 27/32] union-mount: Always create topmost directory on open Jan Blunck
2009-05-18 16:09 ` [PATCH 28/32] union-mount: Basic fallthru definitions Jan Blunck
2009-05-18 16:09 ` [PATCH 29/32] union mount: Support for fallthru entries in union mount lookup Jan Blunck
2009-05-18 16:09 ` [PATCH 30/32] union mount: ext2 fallthru support Jan Blunck
2009-05-18 16:32   ` Andreas Dilger
2009-05-19  9:42     ` Jan Blunck
2009-05-19 14:05       ` Andreas Dilger
2009-05-19 16:13         ` Jan Blunck
2009-05-18 16:09 ` [PATCH 31/32] union-mount: tmpfs " Jan Blunck
2009-05-18 16:09 ` [PATCH 32/32] union-mount: Copy up directory entries on first readdir() Jan Blunck
2009-05-18 20:40 ` [PATCH] Userland for VFS based Union Mount (V3) Valerie Aurora
2009-05-21 13:53   ` Andreas Dilger
2009-06-18  3:22     ` Valerie Aurora
2009-05-19  9:48 ` [PATCH 00/32] " Miklos Szeredi
2009-05-19 10:29   ` Jan Blunck
2009-05-19 10:35     ` Miklos Szeredi
2009-05-19 10:39       ` Jan Blunck
2009-05-19 11:54         ` Arnd Bergmann
2009-05-19 12:15           ` Jan Blunck
2009-05-19 12:21             ` Arnd Bergmann
2009-05-19 13:10               ` Jan Blunck
2009-05-19 17:23   ` Valerie Aurora
2009-05-20  9:05     ` Miklos Szeredi
2009-06-08 19:44       ` Valerie Aurora
2009-06-16 15:19         ` Miklos Szeredi
2009-05-21 12:54 ` Jan Rekorajski
2009-06-08 19:57   ` Valerie Aurora
2009-06-08 22:44     ` Jan Rekorajski
2009-06-08 22:48       ` Valerie Aurora
2009-06-15  9:55         ` Jan Rekorajski
2009-06-18  3:23           ` Valerie Aurora
2009-06-04 11:38 ` Scott James Remnant
2009-06-09 22:15   ` Valerie Aurora

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