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authorAl Viro <viro@zeniv.linux.org.uk>2012-06-10 04:15:17 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-07-14 16:32:56 +0400
commit6d7b5aaed7d887b34f29f900244cdbd17a86637c (patch)
treee94341bc903a57e1c92c03c4953ae041b87f9807 /fs
parent1d674107ea4b68669e012e654d64369b7f2bb250 (diff)
downloadop-kernel-dev-6d7b5aaed7d887b34f29f900244cdbd17a86637c.zip
op-kernel-dev-6d7b5aaed7d887b34f29f900244cdbd17a86637c.tar.gz
namei.c: let follow_link() do put_link() on failure
no need for kludgy "set cookie to ERR_PTR(...) because we failed before we did actual ->follow_link() and want to suppress put_link()", no pointless check in put_link() itself. Callers checked if follow_link() has failed anyway; might as well break out of their loops if that happened, without bothering to call put_link() first. [AV: folded fixes from hch] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r--fs/namei.c74
1 files changed, 41 insertions, 33 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 7d69419..6135a14 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -605,7 +605,7 @@ static inline void path_to_nameidata(const struct path *path,
static inline void put_link(struct nameidata *nd, struct path *link, void *cookie)
{
struct inode *inode = link->dentry->d_inode;
- if (!IS_ERR(cookie) && inode->i_op->put_link)
+ if (inode->i_op->put_link)
inode->i_op->put_link(link->dentry, nd, cookie);
path_put(link);
}
@@ -613,19 +613,19 @@ static inline void put_link(struct nameidata *nd, struct path *link, void *cooki
static __always_inline int
follow_link(struct path *link, struct nameidata *nd, void **p)
{
- int error;
struct dentry *dentry = link->dentry;
+ int error;
+ char *s;
BUG_ON(nd->flags & LOOKUP_RCU);
if (link->mnt == nd->path.mnt)
mntget(link->mnt);
- if (unlikely(current->total_link_count >= 40)) {
- *p = ERR_PTR(-ELOOP); /* no ->put_link(), please */
- path_put(&nd->path);
- return -ELOOP;
- }
+ error = -ELOOP;
+ if (unlikely(current->total_link_count >= 40))
+ goto out_put_nd_path;
+
cond_resched();
current->total_link_count++;
@@ -633,30 +633,37 @@ follow_link(struct path *link, struct nameidata *nd, void **p)
nd_set_link(nd, NULL);
error = security_inode_follow_link(link->dentry, nd);
- if (error) {
- *p = ERR_PTR(error); /* no ->put_link(), please */
- path_put(&nd->path);
- return error;
- }
+ if (error)
+ goto out_put_nd_path;
nd->last_type = LAST_BIND;
*p = dentry->d_inode->i_op->follow_link(dentry, nd);
error = PTR_ERR(*p);
- if (!IS_ERR(*p)) {
- char *s = nd_get_link(nd);
- error = 0;
- if (s)
- error = __vfs_follow_link(nd, s);
- else if (nd->last_type == LAST_BIND) {
- nd->flags |= LOOKUP_JUMPED;
- nd->inode = nd->path.dentry->d_inode;
- if (nd->inode->i_op->follow_link) {
- /* stepped on a _really_ weird one */
- path_put(&nd->path);
- error = -ELOOP;
- }
+ if (IS_ERR(*p))
+ goto out_put_link;
+
+ error = 0;
+ s = nd_get_link(nd);
+ if (s) {
+ error = __vfs_follow_link(nd, s);
+ } else if (nd->last_type == LAST_BIND) {
+ nd->flags |= LOOKUP_JUMPED;
+ nd->inode = nd->path.dentry->d_inode;
+ if (nd->inode->i_op->follow_link) {
+ /* stepped on a _really_ weird one */
+ path_put(&nd->path);
+ error = -ELOOP;
}
}
+ if (unlikely(error))
+ put_link(nd, link, *p);
+
+ return error;
+
+out_put_nd_path:
+ path_put(&nd->path);
+out_put_link:
+ path_put(link);
return error;
}
@@ -1383,9 +1390,10 @@ static inline int nested_symlink(struct path *path, struct nameidata *nd)
void *cookie;
res = follow_link(&link, nd, &cookie);
- if (!res)
- res = walk_component(nd, path, &nd->last,
- nd->last_type, LOOKUP_FOLLOW);
+ if (res)
+ break;
+ res = walk_component(nd, path, &nd->last,
+ nd->last_type, LOOKUP_FOLLOW);
put_link(nd, &link, cookie);
} while (res > 0);
@@ -1777,8 +1785,9 @@ static int path_lookupat(int dfd, const char *name,
struct path link = path;
nd->flags |= LOOKUP_PARENT;
err = follow_link(&link, nd, &cookie);
- if (!err)
- err = lookup_last(nd, &path);
+ if (err)
+ break;
+ err = lookup_last(nd, &path);
put_link(nd, &link, cookie);
}
}
@@ -2475,9 +2484,8 @@ static struct file *path_openat(int dfd, const char *pathname,
nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
error = follow_link(&link, nd, &cookie);
if (unlikely(error))
- filp = ERR_PTR(error);
- else
- filp = do_last(nd, &path, op, pathname);
+ goto out_filp;
+ filp = do_last(nd, &path, op, pathname);
put_link(nd, &link, cookie);
}
out:
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