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>
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Родитель
1d674107ea
Коммит
6d7b5aaed7
74
fs/namei.c
74
fs/namei.c
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@ -605,7 +605,7 @@ static inline void path_to_nameidata(const struct path *path,
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static inline void put_link(struct nameidata *nd, struct path *link, void *cookie)
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{
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struct inode *inode = link->dentry->d_inode;
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if (!IS_ERR(cookie) && inode->i_op->put_link)
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if (inode->i_op->put_link)
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inode->i_op->put_link(link->dentry, nd, cookie);
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path_put(link);
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}
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@ -613,19 +613,19 @@ static inline void put_link(struct nameidata *nd, struct path *link, void *cooki
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static __always_inline int
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follow_link(struct path *link, struct nameidata *nd, void **p)
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{
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int error;
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struct dentry *dentry = link->dentry;
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int error;
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char *s;
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BUG_ON(nd->flags & LOOKUP_RCU);
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if (link->mnt == nd->path.mnt)
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mntget(link->mnt);
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if (unlikely(current->total_link_count >= 40)) {
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*p = ERR_PTR(-ELOOP); /* no ->put_link(), please */
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path_put(&nd->path);
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return -ELOOP;
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}
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error = -ELOOP;
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if (unlikely(current->total_link_count >= 40))
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goto out_put_nd_path;
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cond_resched();
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current->total_link_count++;
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@ -633,30 +633,37 @@ follow_link(struct path *link, struct nameidata *nd, void **p)
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nd_set_link(nd, NULL);
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error = security_inode_follow_link(link->dentry, nd);
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if (error) {
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*p = ERR_PTR(error); /* no ->put_link(), please */
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path_put(&nd->path);
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return error;
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}
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if (error)
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goto out_put_nd_path;
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nd->last_type = LAST_BIND;
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*p = dentry->d_inode->i_op->follow_link(dentry, nd);
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error = PTR_ERR(*p);
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if (!IS_ERR(*p)) {
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char *s = nd_get_link(nd);
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error = 0;
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if (s)
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error = __vfs_follow_link(nd, s);
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else if (nd->last_type == LAST_BIND) {
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nd->flags |= LOOKUP_JUMPED;
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nd->inode = nd->path.dentry->d_inode;
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if (nd->inode->i_op->follow_link) {
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/* stepped on a _really_ weird one */
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path_put(&nd->path);
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error = -ELOOP;
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}
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if (IS_ERR(*p))
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goto out_put_link;
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error = 0;
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s = nd_get_link(nd);
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if (s) {
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error = __vfs_follow_link(nd, s);
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} else if (nd->last_type == LAST_BIND) {
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nd->flags |= LOOKUP_JUMPED;
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nd->inode = nd->path.dentry->d_inode;
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if (nd->inode->i_op->follow_link) {
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/* stepped on a _really_ weird one */
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path_put(&nd->path);
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error = -ELOOP;
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}
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}
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if (unlikely(error))
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put_link(nd, link, *p);
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return error;
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out_put_nd_path:
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path_put(&nd->path);
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out_put_link:
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path_put(link);
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return error;
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}
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@ -1383,9 +1390,10 @@ static inline int nested_symlink(struct path *path, struct nameidata *nd)
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void *cookie;
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res = follow_link(&link, nd, &cookie);
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if (!res)
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res = walk_component(nd, path, &nd->last,
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nd->last_type, LOOKUP_FOLLOW);
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if (res)
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break;
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res = walk_component(nd, path, &nd->last,
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nd->last_type, LOOKUP_FOLLOW);
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put_link(nd, &link, cookie);
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} while (res > 0);
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@ -1777,8 +1785,9 @@ static int path_lookupat(int dfd, const char *name,
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struct path link = path;
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nd->flags |= LOOKUP_PARENT;
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err = follow_link(&link, nd, &cookie);
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if (!err)
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err = lookup_last(nd, &path);
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if (err)
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break;
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err = lookup_last(nd, &path);
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put_link(nd, &link, cookie);
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}
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}
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@ -2475,9 +2484,8 @@ static struct file *path_openat(int dfd, const char *pathname,
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nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
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error = follow_link(&link, nd, &cookie);
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if (unlikely(error))
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filp = ERR_PTR(error);
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else
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filp = do_last(nd, &path, op, pathname);
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goto out_filp;
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filp = do_last(nd, &path, op, pathname);
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put_link(nd, &link, cookie);
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}
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out:
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