From patchwork Wed Dec 11 16:56:20 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sougata Santra X-Patchwork-Id: 3329371 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 990799F1F0 for ; Thu, 12 Dec 2013 00:32:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B2703207D3 for ; Thu, 12 Dec 2013 00:32:42 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 4E6E520800 for ; Thu, 12 Dec 2013 00:32:41 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 265F1FA842; Wed, 11 Dec 2013 16:32:36 -0800 (PST) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org X-Greylist: delayed 310 seconds by postgrey-1.32 at gabe; Wed, 11 Dec 2013 09:01:32 PST Received: from ex10.nebula.fi (nbl-ex10-fe01.nebula.fi [188.117.32.121]) by gabe.freedesktop.org (Postfix) with ESMTP id 17B95FA974 for ; Wed, 11 Dec 2013 09:01:32 -0800 (PST) Received: from [192.168.75.200] (194.100.106.164) by ex10.nebula.fi (188.117.32.115) with Microsoft SMTP Server (TLS) id 14.3.158.1; Wed, 11 Dec 2013 18:56:20 +0200 Message-ID: <1386780980.9524.10.camel@ultrabook> Subject: [PATCH] hfsplus: Remove hfsplus_file_lookup From: Sougata Santra To: Date: Wed, 11 Dec 2013 18:56:20 +0200 Organization: Tuxera X-Mailer: Evolution 3.6.4 (3.6.4-3.fc18) MIME-Version: 1.0 X-Originating-IP: [194.100.106.164] X-Mailman-Approved-At: Wed, 11 Dec 2013 16:32:24 -0800 Cc: linux-fsdevel@vger.kernel.org, Szabolcs Szakacsits , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.13 Precedence: list Reply-To: sougata@tuxera.com List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces@lists.freedesktop.org Errors-To: dri-devel-bounces@lists.freedesktop.org X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 From: Sougata Santra HFS+ resource fork lookup breaks opendir() library function. Since opendir first calls open() with O_DIRECTORY flag set. O_DIRECTORY means "refuse to open if not a directory". The open system call in the kernel does a check for inode->i_op->lookup and returns -ENOTDIR. So if hfsplus_file_lookup is set it allows opendir() for plain files. Also resource fork lookup in HFS+ does not work. Since it is never invoked after VFS permission checking. It will always return with -EACCES. Signed-off-by: Sougata Santra Acked-by: Christoph Hellwig --- When we call opendir() on a file, it does not return NULL. opendir() library call is based on open with O_DIRECTORY flag passed and then layered on top of getdents() system call. O_DIRECTORY means "refuse to open if not a directory". The open() system call in the kernel does a check for: do_sys_open() -->..--> can_lookup() i.e it only checks inode->i_op->lookup and returns ENOTDIR if this function pointer is not set. " In OSX, we can open "file/rsrc" to get the resource fork of "file". This behavior is emulated inside hfsplus on Linux, which means that to some degree every file acts like a directory. That is the reason lookup() inode operations is supported for files, and it is possible to do a lookup on this specific name. As a result of this open succeeds without returning ENOTDIR for HFS+ " Please see the LKML discussion thread on this issue: http://marc.info/?l=linux-fsdevel&m=122823343730412&w=2 I tried to test file/rsrc lookup in HFS+ driver and the feature does not work. From OSX: $ touch test $ echo "1234" > test/..namedfork/rsrc $ ls -l test..namedfork/rsrc --rw-r--r-- 1 tuxera staff 5 10 dec 12:59 test/..namedfork/rsrc [sougata@ultrabook tmp]$ id uid=1000(sougata) gid=1000(sougata) groups=1000(sougata),5(tty),18(dialout),1001(vboxusers) [sougata@ultrabook tmp]$ mount /dev/sdb1 on /mnt/tmp type hfsplus (rw,relatime,umask=0,uid=1000,gid=1000,nls=utf8) [sougata@ultrabook tmp]$ ls -l test/rsrc ls: cannot access test/rsrc: Permission denied According to this LKML thread it is expected behavior. http://marc.info/?t=121139033800008&r=1&w=4 I guess now that permission checking happens in vfs generic_permission() ? So it turns out that even though the lookup() inode_operation exists for HFS+ files. It cannot really get invoked ?. So if we can disable this feature to make opendir() work for HFS+. Thanks, Sougata fs/hfsplus/inode.c | 59 ------------------------------------------------------ 1 file changed, 59 deletions(-) diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c index 37213d0..3ebda92 100644 --- a/fs/hfsplus/inode.c +++ b/fs/hfsplus/inode.c @@ -178,64 +178,6 @@ const struct dentry_operations hfsplus_dentry_operations = { .d_compare = hfsplus_compare_dentry, }; -static struct dentry *hfsplus_file_lookup(struct inode *dir, - struct dentry *dentry, unsigned int flags) -{ - struct hfs_find_data fd; - struct super_block *sb = dir->i_sb; - struct inode *inode = NULL; - struct hfsplus_inode_info *hip; - int err; - - if (HFSPLUS_IS_RSRC(dir) || strcmp(dentry->d_name.name, "rsrc")) - goto out; - - inode = HFSPLUS_I(dir)->rsrc_inode; - if (inode) - goto out; - - inode = new_inode(sb); - if (!inode) - return ERR_PTR(-ENOMEM); - - hip = HFSPLUS_I(inode); - inode->i_ino = dir->i_ino; - INIT_LIST_HEAD(&hip->open_dir_list); - mutex_init(&hip->extents_lock); - hip->extent_state = 0; - hip->flags = 0; - hip->userflags = 0; - set_bit(HFSPLUS_I_RSRC, &hip->flags); - - err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd); - if (!err) { - err = hfsplus_find_cat(sb, dir->i_ino, &fd); - if (!err) - err = hfsplus_cat_read_inode(inode, &fd); - hfs_find_exit(&fd); - } - if (err) { - iput(inode); - return ERR_PTR(err); - } - hip->rsrc_inode = dir; - HFSPLUS_I(dir)->rsrc_inode = inode; - igrab(dir); - - /* - * __mark_inode_dirty expects inodes to be hashed. Since we don't - * want resource fork inodes in the regular inode space, we make them - * appear hashed, but do not put on any lists. hlist_del() - * will work fine and require no locking. - */ - hlist_add_fake(&inode->i_hash); - - mark_inode_dirty(inode); -out: - d_add(dentry, inode); - return NULL; -} - static void hfsplus_get_perms(struct inode *inode, struct hfsplus_perm *perms, int dir) { @@ -385,7 +327,6 @@ int hfsplus_file_fsync(struct file *file, loff_t start, loff_t end, } static const struct inode_operations hfsplus_file_inode_operations = { - .lookup = hfsplus_file_lookup, .setattr = hfsplus_setattr, .setxattr = generic_setxattr, .getxattr = generic_getxattr,