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From: Al Viro <viro@ZenIV.linux.org.uk>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Neil Brown <neilb@suse.de>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH 17/24] link_path_walk: split "return from recursive call" path
Date: Mon, 20 Apr 2015 19:13:01 +0100	[thread overview]
Message-ID: <1429553588-24764-17-git-send-email-viro@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20150420181222.GK889@ZenIV.linux.org.uk>

From: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/namei.c | 40 +++++++++++++++++-----------------------
 1 file changed, 17 insertions(+), 23 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 4b98f4b..975918f 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1883,23 +1883,6 @@ Walked:
 				last->name = name;
 				name = s;
 				goto start;
-
-back:
-				name = last->name;
-				if (unlikely(err)) {
-					put_link(nd, &last->link, last->cookie);
-					nd->link_count--;
-					nd->depth--;
-					last--;
-					goto Err;
-				} else {
-					err = walk_component(nd, &next, LOOKUP_FOLLOW);
-					put_link(nd, &last->link, last->cookie);
-					nd->link_count--;
-					nd->depth--;
-					last--;
-					goto Walked;
-				}
 			}
 		}
 		if (!d_can_lookup(nd->path.dentry)) {
@@ -1909,13 +1892,24 @@ back:
 	}
 	terminate_walk(nd);
 Err:
-	if (likely(!nd->depth))
-		return err;
-	goto back;
+	while (unlikely(nd->depth)) {
+		put_link(nd, &last->link, last->cookie);
+		nd->link_count--;
+		nd->depth--;
+		last--;
+	}
+	return err;
 OK:
-	if (likely(!nd->depth))
-		return 0;
-	goto back;
+	if (unlikely(nd->depth)) {
+		name = last->name;
+		err = walk_component(nd, &next, LOOKUP_FOLLOW);
+		put_link(nd, &last->link, last->cookie);
+		nd->link_count--;
+		nd->depth--;
+		last--;
+		goto Walked;
+	}
+	return 0;
 }
 
 static int path_init(int dfd, const struct filename *name, unsigned int flags,
-- 
2.1.4


  parent reply	other threads:[~2015-04-20 18:14 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-20 18:12 [RFC][PATCHSET] non-recursive link_path_walk() and reducing stack footprint Al Viro
2015-04-20 18:12 ` [PATCH 01/24] lustre: rip the private symlink nesting limit out Al Viro
2015-04-20 19:08   ` Andreas Dilger
2015-04-20 19:22     ` Al Viro
2015-04-20 20:35       ` Al Viro
2015-04-20 18:12 ` [PATCH 02/24] VFS: replace {, total_}link_count in task_struct with pointer to nameidata Al Viro
2015-04-20 18:12 ` [PATCH 03/24] ovl: rearrange ovl_follow_link to it doesn't need to call ->put_link Al Viro
2015-04-20 18:12 ` [PATCH 04/24] VFS: replace nameidata arg to ->put_link with a char* Al Viro
2015-04-20 18:12 ` [PATCH 05/24] SECURITY: remove nameidata arg from inode_follow_link Al Viro
2015-04-20 18:12 ` [PATCH 06/24] VFS: remove nameidata args from ->follow_link Al Viro
2015-04-20 18:12 ` [PATCH 07/24] namei: expand nested_symlink() in its only caller Al Viro
2015-04-20 18:12 ` [PATCH 08/24] namei.c: separate the parts of follow_link() that find the link body Al Viro
2015-04-20 18:12 ` [PATCH 09/24] namei: fold follow_link() into link_path_walk() Al Viro
2015-04-20 18:12 ` [PATCH 10/24] link_path_walk: handle get_link() returning ERR_PTR() immediately Al Viro
2015-04-20 18:12 ` [PATCH 11/24] link_path_walk: don't bother with walk_component() after jumping link Al Viro
2015-04-20 18:12 ` [PATCH 12/24] link_path_walk: turn inner loop into explicit goto Al Viro
2015-04-20 18:12 ` [PATCH 13/24] link_path_walk: massage a bit more Al Viro
2015-04-20 18:12 ` [PATCH 14/24] link_path_walk: get rid of duplication Al Viro
2015-04-20 18:12 ` [PATCH 15/24] link_path_walk: final preparations to killing recursion Al Viro
2015-04-20 18:13 ` [PATCH 16/24] link_path_walk: kill the recursion Al Viro
2015-04-20 21:04   ` Linus Torvalds
2015-04-20 21:32     ` Al Viro
2015-04-20 21:39       ` Linus Torvalds
2015-04-20 21:51         ` Al Viro
2015-04-20 21:41       ` Linus Torvalds
2015-04-20 21:42         ` Linus Torvalds
2015-04-20 21:59           ` Al Viro
2015-04-20 21:52         ` Al Viro
2015-04-20 18:13 ` Al Viro [this message]
2015-04-20 18:13 ` [PATCH 18/24] link_path_walk: cleanup - turn goto start; into continue; Al Viro
2015-04-20 18:13 ` [PATCH 19/24] namei: fold may_follow_link() into follow_link() Al Viro
2015-04-20 18:13 ` [PATCH 20/24] namei: introduce nameidata->stack Al Viro
2015-04-20 18:13 ` [PATCH 21/24] namei: regularize use of put_link() and follow_link(), trim arguments Al Viro
2015-04-20 18:13 ` [PATCH 22/24] namei: trim the arguments of get_link() Al Viro
2015-04-20 18:13 ` [PATCH 23/24] new ->follow_link() and ->put_link() calling conventions Al Viro
2015-04-20 18:13 ` [PATCH 24/24] uninline walk_component() Al Viro
2015-04-21 14:49 ` [RFC][PATCHSET] non-recursive link_path_walk() and reducing stack footprint Al Viro
2015-04-21 15:04   ` Christoph Hellwig
2015-04-21 15:12     ` Richard Weinberger
2015-04-21 15:45       ` Al Viro
2015-04-21 16:46         ` Boaz Harrosh
2015-04-21 21:20         ` Al Viro
2015-04-22 18:07           ` Al Viro
2015-04-22 20:12             ` Al Viro
2015-04-22 21:05               ` Al Viro
2015-04-23  7:45                 ` NeilBrown
2015-04-23 18:07                   ` Al Viro
2015-04-24  6:35                     ` NeilBrown
2015-04-24 13:42                       ` Al Viro
2015-05-04  5:11                         ` Al Viro
2015-05-04  7:30                           ` NeilBrown
2015-04-23  5:01           ` Al Viro

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