From 90e4fc8890daecea72ef73ac8047050e3e8d32db Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 14 Apr 2015 17:42:49 -0400 Subject: [PATCH] 9p: don't bother with __getname() in ->follow_link() We copy there a kmalloc'ed string and proceed to kfree that string immediately after that. Easier to just feed that string to nd_set_link() and _not_ kfree it until ->put_link() (which becomes kfree_put_link() in that case). Signed-off-by: Al Viro --- fs/9p/v9fs.h | 2 - fs/9p/vfs_inode.c | 103 +++++++++-------------------------------- fs/9p/vfs_inode_dotl.c | 31 ++++--------- 3 files changed, 31 insertions(+), 105 deletions(-) diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h index fb9ffcb43277..0923f2cf3c80 100644 --- a/fs/9p/v9fs.h +++ b/fs/9p/v9fs.h @@ -149,8 +149,6 @@ extern int v9fs_vfs_unlink(struct inode *i, struct dentry *d); extern int v9fs_vfs_rmdir(struct inode *i, struct dentry *d); extern int v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry); -extern void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, - void *p); extern struct inode *v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid, struct super_block *sb, int new); diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index cda68f70d757..0ba11712b388 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -1223,54 +1223,6 @@ ino_t v9fs_qid2ino(struct p9_qid *qid) return i; } -/** - * v9fs_readlink - read a symlink's location (internal version) - * @dentry: dentry for symlink - * @buffer: buffer to load symlink location into - * @buflen: length of buffer - * - */ - -static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen) -{ - int retval; - - struct v9fs_session_info *v9ses; - struct p9_fid *fid; - struct p9_wstat *st; - - p9_debug(P9_DEBUG_VFS, " %pd\n", dentry); - retval = -EPERM; - v9ses = v9fs_dentry2v9ses(dentry); - fid = v9fs_fid_lookup(dentry); - if (IS_ERR(fid)) - return PTR_ERR(fid); - - if (!v9fs_proto_dotu(v9ses)) - return -EBADF; - - st = p9_client_stat(fid); - if (IS_ERR(st)) - return PTR_ERR(st); - - if (!(st->mode & P9_DMSYMLINK)) { - retval = -EINVAL; - goto done; - } - - /* copy extension buffer into buffer */ - retval = min(strlen(st->extension)+1, (size_t)buflen); - memcpy(buffer, st->extension, retval); - - p9_debug(P9_DEBUG_VFS, "%pd -> %s (%.*s)\n", - dentry, st->extension, buflen, buffer); - -done: - p9stat_free(st); - kfree(st); - return retval; -} - /** * v9fs_vfs_follow_link - follow a symlink path * @dentry: dentry for symlink @@ -1280,46 +1232,37 @@ done: static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd) { - int len = 0; - char *link = __getname(); + struct v9fs_session_info *v9ses = v9fs_dentry2v9ses(dentry); + struct p9_fid *fid = v9fs_fid_lookup(dentry); + struct p9_wstat *st; p9_debug(P9_DEBUG_VFS, "%pd\n", dentry); - if (!link) - link = ERR_PTR(-ENOMEM); - else { - len = v9fs_readlink(dentry, link, PATH_MAX); + if (IS_ERR(fid)) + return ERR_CAST(fid); - if (len < 0) { - __putname(link); - link = ERR_PTR(len); - } else - link[min(len, PATH_MAX-1)] = 0; + if (!v9fs_proto_dotu(v9ses)) + return ERR_PTR(-EBADF); + + st = p9_client_stat(fid); + if (IS_ERR(st)) + return ERR_CAST(st); + + if (!(st->mode & P9_DMSYMLINK)) { + p9stat_free(st); + kfree(st); + return ERR_PTR(-EINVAL); } - nd_set_link(nd, link); + if (strlen(st->extension) >= PATH_MAX) + st->extension[PATH_MAX - 1] = '\0'; + nd_set_link(nd, st->extension); + st->extension = NULL; + p9stat_free(st); + kfree(st); return NULL; } -/** - * v9fs_vfs_put_link - release a symlink path - * @dentry: dentry for symlink - * @nd: nameidata - * @p: unused - * - */ - -void -v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p) -{ - char *s = nd_get_link(nd); - - p9_debug(P9_DEBUG_VFS, " %pd %s\n", - dentry, IS_ERR(s) ? "" : s); - if (!IS_ERR(s)) - __putname(s); -} - /** * v9fs_vfs_mkspecial - create a special file * @dir: inode to create special file in @@ -1514,7 +1457,7 @@ static const struct inode_operations v9fs_file_inode_operations = { static const struct inode_operations v9fs_symlink_inode_operations = { .readlink = generic_readlink, .follow_link = v9fs_vfs_follow_link, - .put_link = v9fs_vfs_put_link, + .put_link = kfree_put_link, .getattr = v9fs_vfs_getattr, .setattr = v9fs_vfs_setattr, }; diff --git a/fs/9p/vfs_inode_dotl.c b/fs/9p/vfs_inode_dotl.c index 9861c7c951a6..bc2a91f2b910 100644 --- a/fs/9p/vfs_inode_dotl.c +++ b/fs/9p/vfs_inode_dotl.c @@ -912,33 +912,18 @@ error: static void * v9fs_vfs_follow_link_dotl(struct dentry *dentry, struct nameidata *nd) { - int retval; - struct p9_fid *fid; - char *link = __getname(); + struct p9_fid *fid = v9fs_fid_lookup(dentry); char *target; + int retval; p9_debug(P9_DEBUG_VFS, "%pd\n", dentry); - if (!link) { - link = ERR_PTR(-ENOMEM); - goto ndset; - } - fid = v9fs_fid_lookup(dentry); - if (IS_ERR(fid)) { - __putname(link); - link = ERR_CAST(fid); - goto ndset; - } + if (IS_ERR(fid)) + return ERR_CAST(fid); retval = p9_client_readlink(fid, &target); - if (!retval) { - strcpy(link, target); - kfree(target); - goto ndset; - } - __putname(link); - link = ERR_PTR(retval); -ndset: - nd_set_link(nd, link); + if (retval) + return ERR_PTR(retval); + nd_set_link(nd, target); return NULL; } @@ -1006,7 +991,7 @@ const struct inode_operations v9fs_file_inode_operations_dotl = { const struct inode_operations v9fs_symlink_inode_operations_dotl = { .readlink = generic_readlink, .follow_link = v9fs_vfs_follow_link_dotl, - .put_link = v9fs_vfs_put_link, + .put_link = kfree_put_link, .getattr = v9fs_vfs_getattr_dotl, .setattr = v9fs_vfs_setattr_dotl, .setxattr = generic_setxattr,