diff options
author | Al Viro <viro@zeniv.linux.org.uk> | 2012-06-10 10:15:17 +0200 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-07-14 14:32:56 +0200 |
commit | 6d7b5aaed7d887b34f29f900244cdbd17a86637c (patch) | |
tree | e94341bc903a57e1c92c03c4953ae041b87f9807 /fs | |
parent | coda: use list_for_each_entry (diff) | |
download | linux-6d7b5aaed7d887b34f29f900244cdbd17a86637c.tar.xz linux-6d7b5aaed7d887b34f29f900244cdbd17a86637c.zip |
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.c | 74 |
1 files changed, 41 insertions, 33 deletions
diff --git a/fs/namei.c b/fs/namei.c index 7d694194024a..6135a14d5a84 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: |