From patchwork Tue Apr 14 21:44:24 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 6218291 Return-Path: X-Original-To: patchwork-v9fs-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id AC7849F313 for ; Tue, 14 Apr 2015 21:44:45 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 929CF202E5 for ; Tue, 14 Apr 2015 21:44:44 +0000 (UTC) Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4A8C52021F for ; Tue, 14 Apr 2015 21:44:43 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=sfs-ml-2.v29.ch3.sourceforge.com) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Yi8dK-0007kM-S8; Tue, 14 Apr 2015 21:44:38 +0000 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Yi8dJ-0007kD-KB for v9fs-developer@lists.sourceforge.net; Tue, 14 Apr 2015 21:44:37 +0000 X-ACL-Warn: Received: from zeniv.linux.org.uk ([195.92.253.2]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1Yi8dH-0006VB-Oy for v9fs-developer@lists.sourceforge.net; Tue, 14 Apr 2015 21:44:37 +0000 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.76 #1 (Red Hat Linux)) id 1Yi8d6-0001wO-MT; Tue, 14 Apr 2015 21:44:24 +0000 Date: Tue, 14 Apr 2015 22:44:24 +0100 From: Al Viro To: Eric Van Hensbergen Message-ID: <20150414214424.GI889@ZenIV.linux.org.uk> References: <20140702135258.23882.15100.malonedeb@soybean.canonical.com> <20150410123059.26540.1036.malone@gac.canonical.com> <20150413082753.GA15891@u-blusson> <20150414160737.GX889@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-Spam-Score: -0.0 (/) X-Headers-End: 1Yi8dH-0006VB-Oy Cc: Linux FS Devel , V9FS Developers , qemu-devel , Bug 1336794 <1336794@bugs.launchpad.net> Subject: Re: [V9fs-developer] [Qemu-devel] [Bug 1336794] Re: 9pfs does not honor open file handles on unlinked files X-BeenThere: v9fs-developer@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: v9fs-developer-bounces@lists.sourceforge.net X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Tue, Apr 14, 2015 at 04:19:41PM +0000, Eric Van Hensbergen wrote: > That patch looks fine by me. Happy to put it in the queue. Thanks Al. OK... Here's one more: 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 --- ------------------------------------------------------------------------------ BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT Develop your own process in accordance with the BPMN 2 standard Learn Process modeling best practices with Bonita BPM through live exercises http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_ source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF diff --git a/fs/9p/v9fs.h b/fs/9p/v9fs.h index 099c771..48d35d8 100644 --- a/fs/9p/v9fs.h +++ b/fs/9p/v9fs.h @@ -150,8 +150,6 @@ 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 cda68f7..0ba1171 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -1224,103 +1224,46 @@ ino_t v9fs_qid2ino(struct p9_qid *qid) } /** - * v9fs_readlink - read a symlink's location (internal version) + * v9fs_vfs_follow_link - follow a symlink path * @dentry: dentry for symlink - * @buffer: buffer to load symlink location into - * @buflen: length of buffer + * @nd: nameidata * */ -static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen) +static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd) { - int retval; - - struct v9fs_session_info *v9ses; - struct p9_fid *fid; + 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); - retval = -EPERM; - v9ses = v9fs_dentry2v9ses(dentry); - fid = v9fs_fid_lookup(dentry); + p9_debug(P9_DEBUG_VFS, "%pd\n", dentry); + if (IS_ERR(fid)) - return PTR_ERR(fid); + return ERR_CAST(fid); if (!v9fs_proto_dotu(v9ses)) - return -EBADF; + return ERR_PTR(-EBADF); st = p9_client_stat(fid); if (IS_ERR(st)) - return PTR_ERR(st); + return ERR_CAST(st); if (!(st->mode & P9_DMSYMLINK)) { - retval = -EINVAL; - goto done; + p9stat_free(st); + kfree(st); + return ERR_PTR(-EINVAL); } + if (strlen(st->extension) >= PATH_MAX) + st->extension[PATH_MAX - 1] = '\0'; - /* 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: + nd_set_link(nd, st->extension); + st->extension = NULL; p9stat_free(st); kfree(st); - return retval; -} - -/** - * v9fs_vfs_follow_link - follow a symlink path - * @dentry: dentry for symlink - * @nd: nameidata - * - */ - -static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd) -{ - int len = 0; - char *link = __getname(); - - p9_debug(P9_DEBUG_VFS, "%pd\n", dentry); - - if (!link) - link = ERR_PTR(-ENOMEM); - else { - len = v9fs_readlink(dentry, link, PATH_MAX); - - if (len < 0) { - __putname(link); - link = ERR_PTR(len); - } else - link[min(len, PATH_MAX-1)] = 0; - } - nd_set_link(nd, link); - 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 * @dentry: dentry to create @@ -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 9861c7c..bc2a91f 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,