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 12/24] link_path_walk: turn inner loop into explicit goto
Date: Mon, 20 Apr 2015 19:12:56 +0100 [thread overview]
Message-ID: <1429553588-24764-12-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 | 61 ++++++++++++++++++++++++++++++++-----------------------------
1 file changed, 32 insertions(+), 29 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index 5366b6d..86d54e5 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1832,6 +1832,10 @@ static int link_path_walk(const char *name, struct nameidata *nd)
return err;
if (err) {
+ struct path link;
+ void *cookie;
+ char *s;
+
if (unlikely(nd->link_count >= MAX_NESTED_LINKS)) {
path_put_conditional(&next, nd);
path_put(&nd->path);
@@ -1842,41 +1846,40 @@ static int link_path_walk(const char *name, struct nameidata *nd)
nd->depth++;
nd->link_count++;
- do {
- struct path link = next;
- void *cookie;
- char *s = get_link(&link, nd, &cookie);
-
- if (unlikely(IS_ERR(s))) {
- err = PTR_ERR(s);
- nd->link_count--;
- nd->depth--;
- return err;
+l:
+ link = next;
+ s = get_link(&link, nd, &cookie);
+
+ if (unlikely(IS_ERR(s))) {
+ err = PTR_ERR(s);
+ nd->link_count--;
+ nd->depth--;
+ return err;
+ }
+ err = 0;
+ if (unlikely(!s)) {
+ /* jumped */
+ put_link(nd, &link, cookie);
+ } else {
+ if (*s == '/') {
+ if (!nd->root.mnt)
+ set_root(nd);
+ path_put(&nd->path);
+ nd->path = nd->root;
+ path_get(&nd->root);
+ nd->flags |= LOOKUP_JUMPED;
}
- err = 0;
- if (unlikely(!s)) {
- /* jumped */
+ nd->inode = nd->path.dentry->d_inode;
+ err = link_path_walk(s, nd);
+ if (unlikely(err)) {
put_link(nd, &link, cookie);
- break;
} else {
- if (*s == '/') {
- if (!nd->root.mnt)
- set_root(nd);
- path_put(&nd->path);
- nd->path = nd->root;
- path_get(&nd->root);
- nd->flags |= LOOKUP_JUMPED;
- }
- nd->inode = nd->path.dentry->d_inode;
- err = link_path_walk(s, nd);
- if (unlikely(err)) {
- put_link(nd, &link, cookie);
- break;
- }
err = walk_component(nd, &next, LOOKUP_FOLLOW);
put_link(nd, &link, cookie);
+ if (err > 0)
+ goto l;
}
- } while (err > 0);
+ }
nd->link_count--;
nd->depth--;
--
2.1.4
next prev parent reply other threads:[~2015-04-20 18:17 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 ` Al Viro [this message]
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 ` [PATCH 17/24] link_path_walk: split "return from recursive call" path Al Viro
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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