From: NeilBrown Subject: [PATCH 002 of 8] knfsd: exportfs: remove iget abuse Date: Tue, 15 May 2007 17:16:14 +1000 Message-ID: <1070515071614.16259@suse.de> References: <20070515170405.15621.patches@notabene> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: Neil Brown , linux-kernel@vger.kernel.org, Christoph Hellwig , nfs@lists.sourceforge.net, shaggy@austin.ibm.com, Christoph Hellwig To: Andrew Morton Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list2-new.sourceforge.net with esmtp (Exim 4.43) id 1HnrGo-00042l-E0 for nfs@lists.sourceforge.net; Tue, 15 May 2007 00:16:30 -0700 Received: from ns2.suse.de ([195.135.220.15] helo=mx2.suse.de) by mail.sourceforge.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.44) id 1HnrGq-0007iC-6d for nfs@lists.sourceforge.net; Tue, 15 May 2007 00:16:33 -0700 List-Id: "Discussion of NFS under Linux development, interoperability, and testing." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: nfs-bounces@lists.sourceforge.net Errors-To: nfs-bounces@lists.sourceforge.net From: Christoph Hellwig When the exportfs interface was added the expectation was that filesystems provide an operation to convert from a file handle to an inode/dentry, but it kept a backwards compat option that still calls into iget. Calling into iget from non-filesystem code is very bad, because it gives too little information to filesystem, and simply crashes if the filesystem doesn't implement the ->read_inode routine. Fortunately there are only two filesystems left using this fallback: efs and jfs. This patch moves a copy of export_iget to each of those to implement the get_dentry method. While this is a temporary increase of lines of code in the kernel it allows for a much cleaner interface and important code restructuring in later patches. Cc: shaggy@austin.ibm.com Signed-off-by: Christoph Hellwig Signed-off-by: Neil Brown ### Diffstat output ./fs/efs/namei.c | 32 ++++++++++++++++++++++++++ ./fs/efs/super.c | 1 ./fs/exportfs/expfs.c | 56 ++--------------------------------------------- ./fs/jfs/jfs_inode.h | 2 - ./fs/jfs/namei.c | 32 ++++++++++++++++++++++++++ ./fs/jfs/super.c | 1 ./include/linux/efs_fs.h | 1 7 files changed, 71 insertions(+), 54 deletions(-) diff .prev/fs/efs/namei.c ./fs/efs/namei.c --- .prev/fs/efs/namei.c 2007-05-14 11:14:52.000000000 +1000 +++ ./fs/efs/namei.c 2007-05-14 11:15:29.000000000 +1000 @@ -75,6 +75,38 @@ struct dentry *efs_lookup(struct inode * return NULL; } +struct dentry *efs_get_dentry(struct super_block *sb, void *vobjp) +{ + __u32 *objp = vobjp; + unsigned long ino = objp[0]; + __u32 generation = objp[1]; + struct inode *inode; + struct dentry *result; + + if (ino == 0) + return ERR_PTR(-ESTALE); + inode = iget(sb, ino); + if (inode == NULL) + return ERR_PTR(-ENOMEM); + + if (is_bad_inode(inode) || + (generation && inode->i_generation != generation)) { + result = ERR_PTR(-ESTALE); + goto out_iput; + } + + result = d_alloc_anon(inode); + if (!result) { + result = ERR_PTR(-ENOMEM); + goto out_iput; + } + return result; + + out_iput: + iput(inode); + return result; +} + struct dentry *efs_get_parent(struct dentry *child) { struct dentry *parent; diff .prev/fs/efs/super.c ./fs/efs/super.c --- .prev/fs/efs/super.c 2007-05-14 11:15:23.000000000 +1000 +++ ./fs/efs/super.c 2007-05-14 11:15:29.000000000 +1000 @@ -115,6 +115,7 @@ static const struct super_operations efs }; static struct export_operations efs_export_ops = { + .get_dentry = efs_get_dentry, .get_parent = efs_get_parent, }; diff .prev/fs/exportfs/expfs.c ./fs/exportfs/expfs.c --- .prev/fs/exportfs/expfs.c 2007-05-14 11:15:23.000000000 +1000 +++ ./fs/exportfs/expfs.c 2007-05-14 11:15:29.000000000 +1000 @@ -391,61 +391,11 @@ out: return error; } - -static struct dentry *export_iget(struct super_block *sb, unsigned long ino, __u32 generation) +static struct dentry *get_dentry(struct super_block *sb, void *vobjp) { - - /* iget isn't really right if the inode is currently unallocated!! - * This should really all be done inside each filesystem - * - * ext2fs' read_inode has been strengthed to return a bad_inode if - * the inode had been deleted. - * - * Currently we don't know the generation for parent directory, so - * a generation of 0 means "accept any" - */ - struct inode *inode; - struct dentry *result; - if (ino == 0) - return ERR_PTR(-ESTALE); - inode = iget(sb, ino); - if (inode == NULL) - return ERR_PTR(-ENOMEM); - if (is_bad_inode(inode) - || (generation && inode->i_generation != generation) - ) { - /* we didn't find the right inode.. */ - dprintk("fh_verify: Inode %lu, Bad count: %d %d or version %u %u\n", - inode->i_ino, - inode->i_nlink, atomic_read(&inode->i_count), - inode->i_generation, - generation); - - iput(inode); - return ERR_PTR(-ESTALE); - } - /* now to find a dentry. - * If possible, get a well-connected one - */ - result = d_alloc_anon(inode); - if (!result) { - iput(inode); - return ERR_PTR(-ENOMEM); - } - return result; + return ERR_PTR(-ESTALE); } - -static struct dentry *get_object(struct super_block *sb, void *vobjp) -{ - __u32 *objp = vobjp; - unsigned long ino = objp[0]; - __u32 generation = objp[1]; - - return export_iget(sb, ino, generation); -} - - /** * export_encode_fh - default export_operations->encode_fh function * @dentry: the dentry to encode @@ -524,7 +474,7 @@ struct export_operations export_op_defau .get_name = get_name, .get_parent = get_parent, - .get_dentry = get_object, + .get_dentry = get_dentry, }; EXPORT_SYMBOL(export_op_default); diff .prev/fs/jfs/jfs_inode.h ./fs/jfs/jfs_inode.h --- .prev/fs/jfs/jfs_inode.h 2007-05-14 11:14:52.000000000 +1000 +++ ./fs/jfs/jfs_inode.h 2007-05-14 11:15:29.000000000 +1000 @@ -31,7 +31,7 @@ extern void jfs_truncate(struct inode *) extern void jfs_truncate_nolock(struct inode *, loff_t); extern void jfs_free_zero_link(struct inode *); extern struct dentry *jfs_get_parent(struct dentry *dentry); -extern void jfs_get_inode_flags(struct jfs_inode_info *); +extern struct dentry *jfs_get_dentry(struct super_block *sb, void *vobjp); extern void jfs_set_inode_flags(struct inode *); extern int jfs_get_block(struct inode *, sector_t, struct buffer_head *, int); diff .prev/fs/jfs/namei.c ./fs/jfs/namei.c --- .prev/fs/jfs/namei.c 2007-05-14 11:14:52.000000000 +1000 +++ ./fs/jfs/namei.c 2007-05-14 11:15:29.000000000 +1000 @@ -1477,6 +1477,38 @@ static struct dentry *jfs_lookup(struct return dentry; } +struct dentry *jfs_get_dentry(struct super_block *sb, void *vobjp) +{ + __u32 *objp = vobjp; + unsigned long ino = objp[0]; + __u32 generation = objp[1]; + struct inode *inode; + struct dentry *result; + + if (ino == 0) + return ERR_PTR(-ESTALE); + inode = iget(sb, ino); + if (inode == NULL) + return ERR_PTR(-ENOMEM); + + if (is_bad_inode(inode) || + (generation && inode->i_generation != generation)) { + result = ERR_PTR(-ESTALE); + goto out_iput; + } + + result = d_alloc_anon(inode); + if (!result) { + result = ERR_PTR(-ENOMEM); + goto out_iput; + } + return result; + + out_iput: + iput(inode); + return result; +} + struct dentry *jfs_get_parent(struct dentry *dentry) { struct super_block *sb = dentry->d_inode->i_sb; diff .prev/fs/jfs/super.c ./fs/jfs/super.c --- .prev/fs/jfs/super.c 2007-05-14 11:15:23.000000000 +1000 +++ ./fs/jfs/super.c 2007-05-14 11:15:29.000000000 +1000 @@ -738,6 +738,7 @@ static const struct super_operations jfs }; static struct export_operations jfs_export_operations = { + .get_dentry = jfs_get_dentry, .get_parent = jfs_get_parent, }; diff .prev/include/linux/efs_fs.h ./include/linux/efs_fs.h --- .prev/include/linux/efs_fs.h 2007-05-14 11:14:52.000000000 +1000 +++ ./include/linux/efs_fs.h 2007-05-14 11:15:29.000000000 +1000 @@ -45,6 +45,7 @@ extern efs_block_t efs_map_block(struct extern int efs_get_block(struct inode *, sector_t, struct buffer_head *, int); extern struct dentry *efs_lookup(struct inode *, struct dentry *, struct nameidata *); +extern struct dentry *efs_get_dentry(struct super_block *sb, void *vobjp); extern struct dentry *efs_get_parent(struct dentry *); extern int efs_bmap(struct inode *, int); ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. 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