Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030608AbWLIMRX (ORCPT ); Sat, 9 Dec 2006 07:17:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S936958AbWLIMRW (ORCPT ); Sat, 9 Dec 2006 07:17:22 -0500 Received: from ms-smtp-04.southeast.rr.com ([24.25.9.103]:48449 "EHLO ms-smtp-04.southeast.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936974AbWLIMRV (ORCPT ); Sat, 9 Dec 2006 07:17:21 -0500 Message-ID: <457AA94E.2030209@poochiereds.net> Date: Sat, 09 Dec 2006 07:17:18 -0500 From: Jeff Layton User-Agent: Thunderbird 1.5.0.8 (X11/20061107) MIME-Version: 1.0 To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 2/3] ensure unique i_ino in filesystems without permanent inode numbers (libfs superblock cleanup) References: <457891F4.8030501@redhat.com> In-Reply-To: <457891F4.8030501@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6356 Lines: 174 Jeff Layton wrote: > This patch ensures that the inodes allocated by the functions get_sb_pseudo > and simple_fill_super are unique, provided of course, that the filesystems > calling them play by the rules. Currently that isn't the case, but will be > as I get to each of the filesystems. > This patch is respun based on some suggestions by Josef Sipek. The different modes of simple_fill_super are different enough that they probably ought to be different functions. This makes that so. With this patch it's not necessary to change some of the callers of simple_fill_super yet, but they'll need to be changed sometime so I left that in place. Signed-off-by: Jeff Layton diff --git a/drivers/infiniband/hw/ipath/ipath_fs.c b/drivers/infiniband/hw/ipath/ipath_fs.c diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 137d76c..3f9dd93 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -107,7 +107,7 @@ static int debug_fill_super(struct super { static struct tree_descr debug_files[] = {{""}}; - return simple_fill_super(sb, DEBUGFS_MAGIC, debug_files); + return registered_fill_super(sb, DEBUGFS_MAGIC, debug_files); } static int debug_get_sb(struct file_system_type *fs_type, diff --git a/fs/fuse/control.c b/fs/fuse/control.c index 8c58bd4..1320066 100644 --- a/fs/fuse/control.c +++ b/fs/fuse/control.c @@ -163,7 +163,7 @@ static int fuse_ctl_fill_super(struct su struct fuse_conn *fc; int err; - err = simple_fill_super(sb, FUSE_CTL_SUPER_MAGIC, &empty_descr); + err = registered_fill_super(sb, FUSE_CTL_SUPER_MAGIC, &empty_descr); if (err) return err; diff --git a/fs/libfs.c b/fs/libfs.c index 503898d..ba1a887 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -215,7 +215,7 @@ int get_sb_pseudo(struct file_system_typ s->s_op = ops ? ops : &default_ops; s->s_time_gran = 1; root = new_inode(s); - if (!root) + if (!root || iunique_register(root, 0)) goto Enomem; root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR; root->i_uid = root->i_gid = 0; @@ -356,7 +356,8 @@ int simple_commit_write(struct file *fil return 0; } -int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files) +static int __simple_fill_super(struct super_block *s, int magic, + struct tree_descr *files, int sequential) { static struct super_operations s_ops = {.statfs = simple_statfs}; struct inode *inode; @@ -380,6 +381,12 @@ int simple_fill_super(struct super_block inode->i_op = &simple_dir_inode_operations; inode->i_fop = &simple_dir_operations; inode->i_nlink = 2; + /* + * set this as high as a 32 bit val as possible to avoid collisions. + * This is also well above the highest value that iunique_register + * will assign to an inode + */ + inode->i_ino = 0xffffffff; root = d_alloc_root(inode); if (!root) { iput(inode); @@ -394,12 +401,15 @@ int simple_fill_super(struct super_block inode = new_inode(s); if (!inode) goto out; + if (sequential) + inode->i_ino = i; + else if (iunique_register(inode, 0)) + goto out; inode->i_mode = S_IFREG | files->mode; inode->i_uid = inode->i_gid = 0; inode->i_blocks = 0; inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; inode->i_fop = files->ops; - inode->i_ino = i; d_add(dentry, inode); } s->s_root = root; @@ -410,6 +420,30 @@ out: return -ENOMEM; } +/* + * Fill a superblock with a standard set of fields, and add the entries in the + * "files" struct. Assign i_ino values to the files sequentially. This function + * is appropriate for filesystems that need a particular i_ino value assigned + * to a particular "files" entry. + */ +int simple_fill_super(struct super_block *s, int magic, + struct tree_descr *files) +{ + return __simple_fill_super(s, magic, files, 1); +} + +/* + * Just like simple_fill_super, but does an iunique_register on the inodes + * created for "files" entries. This function is appropriate when you don't + * need a particular i_ino value assigned to each files entry, and when the + * filesystem will have other registered inodes. + */ +int registered_fill_super(struct super_block *s, int magic, + struct tree_descr *files) +{ + return __simple_fill_super(s, magic, files, 0); +} + static DEFINE_SPINLOCK(pin_fs_lock); int simple_pin_fs(struct file_system_type *type, struct vfsmount **mount, int *count) @@ -619,6 +653,7 @@ EXPORT_SYMBOL(simple_dir_operations); EXPORT_SYMBOL(simple_empty); EXPORT_SYMBOL(d_alloc_name); EXPORT_SYMBOL(simple_fill_super); +EXPORT_SYMBOL(registered_fill_super); EXPORT_SYMBOL(simple_getattr); EXPORT_SYMBOL(simple_link); EXPORT_SYMBOL(simple_lookup); diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c diff --git a/include/linux/fs.h b/include/linux/fs.h index 6c70f1a..c98bc80 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1879,7 +1879,10 @@ extern const struct file_operations simp extern struct inode_operations simple_dir_inode_operations; struct tree_descr { char *name; const struct file_operations *ops; int mode; }; struct dentry *d_alloc_name(struct dentry *, const char *); -extern int simple_fill_super(struct super_block *, int, struct tree_descr *); +extern int simple_fill_super(struct super_block *s, int magic, + struct tree_descr *files); +extern int registered_fill_super(struct super_block *s, int magic, + struct tree_descr *files); extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count); extern void simple_release_fs(struct vfsmount **mount, int *count); diff --git a/security/inode.c b/security/inode.c index 9b16e14..e3e12b1 100644 --- a/security/inode.c +++ b/security/inode.c @@ -130,7 +130,7 @@ static int fill_super(struct super_block { static struct tree_descr files[] = {{""}}; - return simple_fill_super(sb, SECURITYFS_MAGIC, files); + return registered_fill_super(sb, SECURITYFS_MAGIC, files); } static int get_sb(struct file_system_type *fs_type, diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/