From 815409d22df870ea0b0d86f2a3bf33c35bcef55c Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 16 Apr 2010 16:22:46 -0400 Subject: NFSv4: Eliminate nfs4_path_walk() All we really want is the ability to retrieve the root file handle. We no longer need the ability to walk down the path, since that is now done in nfs_follow_remote_path(). Signed-off-by: Trond Myklebust --- fs/nfs/getroot.c | 115 +++++++++++-------------------------------------------- 1 file changed, 22 insertions(+), 93 deletions(-) (limited to 'fs/nfs/getroot.c') diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index b35d2a616066..ada369a5647b 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -122,115 +122,44 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh) #ifdef CONFIG_NFS_V4 -/* - * Do a simple pathwalk from the root FH of the server to the nominated target - * of the mountpoint - * - give error on symlinks - * - give error on ".." occurring in the path - * - follow traversals - */ -int nfs4_path_walk(struct nfs_server *server, - struct nfs_fh *mntfh, - const char *path) +int nfs4_get_rootfh(struct nfs_server *server, struct nfs_fh *mntfh) { struct nfs_fsinfo fsinfo; - struct nfs_fattr fattr; - struct nfs_fh lastfh; - struct qstr name; - int ret; + int ret = -ENOMEM; - dprintk("--> nfs4_path_walk(,,%s)\n", path); + dprintk("--> nfs4_get_rootfh()\n"); - fsinfo.fattr = &fattr; - nfs_fattr_init(&fattr); - - /* Eat leading slashes */ - while (*path == '/') - path++; + fsinfo.fattr = nfs_alloc_fattr(); + if (fsinfo.fattr == NULL) + goto out; /* Start by getting the root filehandle from the server */ ret = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo); if (ret < 0) { - dprintk("nfs4_get_root: getroot error = %d\n", -ret); - return ret; + dprintk("nfs4_get_rootfh: getroot error = %d\n", -ret); + goto out; } - if (!S_ISDIR(fattr.mode)) { - printk(KERN_ERR "nfs4_get_root:" + if (!(fsinfo.fattr->valid & NFS_ATTR_FATTR_MODE) + || !S_ISDIR(fsinfo.fattr->mode)) { + printk(KERN_ERR "nfs4_get_rootfh:" " getroot encountered non-directory\n"); - return -ENOTDIR; + ret = -ENOTDIR; + goto out; } - /* FIXME: It is quite valid for the server to return a referral here */ - if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) { - printk(KERN_ERR "nfs4_get_root:" + if (fsinfo.fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) { + printk(KERN_ERR "nfs4_get_rootfh:" " getroot obtained referral\n"); - return -EREMOTE; + ret = -EREMOTE; + goto out; } -next_component: - dprintk("Next: %s\n", path); - - /* extract the next bit of the path */ - if (!*path) - goto path_walk_complete; - - name.name = path; - while (*path && *path != '/') - path++; - name.len = path - (const char *) name.name; - - if (name.len > NFS4_MAXNAMLEN) - return -ENAMETOOLONG; - -eat_dot_dir: - while (*path == '/') - path++; - - if (path[0] == '.' && (path[1] == '/' || !path[1])) { - path += 2; - goto eat_dot_dir; - } - - /* FIXME: Why shouldn't the user be able to use ".." in the path? */ - if (path[0] == '.' && path[1] == '.' && (path[2] == '/' || !path[2]) - ) { - printk(KERN_ERR "nfs4_get_root:" - " Mount path contains reference to \"..\"\n"); - return -EINVAL; - } - - /* lookup the next FH in the sequence */ - memcpy(&lastfh, mntfh, sizeof(lastfh)); - - dprintk("LookupFH: %*.*s [%s]\n", name.len, name.len, name.name, path); - - ret = server->nfs_client->rpc_ops->lookupfh(server, &lastfh, &name, - mntfh, &fattr); - if (ret < 0) { - dprintk("nfs4_get_root: getroot error = %d\n", -ret); - return ret; - } - - if (!S_ISDIR(fattr.mode)) { - printk(KERN_ERR "nfs4_get_root:" - " lookupfh encountered non-directory\n"); - return -ENOTDIR; - } - - /* FIXME: Referrals are quite valid here too */ - if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) { - printk(KERN_ERR "nfs4_get_root:" - " lookupfh obtained referral\n"); - return -EREMOTE; - } - - goto next_component; - -path_walk_complete: - memcpy(&server->fsid, &fattr.fsid, sizeof(server->fsid)); - dprintk("<-- nfs4_path_walk() = 0\n"); - return 0; + memcpy(&server->fsid, &fsinfo.fattr->fsid, sizeof(server->fsid)); +out: + nfs_free_fattr(fsinfo.fattr); + dprintk("<-- nfs4_get_rootfh() = %d\n", ret); + return ret; } /* -- cgit v1.2.3 From 8bac9db9cf85f2518cb523bb1d69c481975c1f9a Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 16 Apr 2010 16:22:48 -0400 Subject: NFSv4: Reduce stack footprint of nfs4_get_root() Signed-off-by: Trond Myklebust --- fs/nfs/getroot.c | 76 ++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 46 insertions(+), 30 deletions(-) (limited to 'fs/nfs/getroot.c') diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index ada369a5647b..7428f7d6273b 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -78,46 +78,52 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh) { struct nfs_server *server = NFS_SB(sb); struct nfs_fsinfo fsinfo; - struct nfs_fattr fattr; - struct dentry *mntroot; + struct dentry *ret; struct inode *inode; int error; /* get the actual root for this mount */ - fsinfo.fattr = &fattr; + fsinfo.fattr = nfs_alloc_fattr(); + if (fsinfo.fattr == NULL) + return ERR_PTR(-ENOMEM); error = server->nfs_client->rpc_ops->getroot(server, mntfh, &fsinfo); if (error < 0) { dprintk("nfs_get_root: getattr error = %d\n", -error); - return ERR_PTR(error); + ret = ERR_PTR(error); + goto out; } inode = nfs_fhget(sb, mntfh, fsinfo.fattr); if (IS_ERR(inode)) { dprintk("nfs_get_root: get root inode failed\n"); - return ERR_CAST(inode); + ret = ERR_CAST(inode); + goto out; } error = nfs_superblock_set_dummy_root(sb, inode); - if (error != 0) - return ERR_PTR(error); + if (error != 0) { + ret = ERR_PTR(error); + goto out; + } /* root dentries normally start off anonymous and get spliced in later * if the dentry tree reaches them; however if the dentry already * exists, we'll pick it up at this point and use it as the root */ - mntroot = d_obtain_alias(inode); - if (IS_ERR(mntroot)) { + ret = d_obtain_alias(inode); + if (IS_ERR(ret)) { dprintk("nfs_get_root: get root dentry failed\n"); - return mntroot; + goto out; } - security_d_instantiate(mntroot, inode); + security_d_instantiate(ret, inode); - if (!mntroot->d_op) - mntroot->d_op = server->nfs_client->rpc_ops->dentry_ops; - - return mntroot; + if (ret->d_op == NULL) + ret->d_op = server->nfs_client->rpc_ops->dentry_ops; +out: + nfs_free_fattr(fsinfo.fattr); + return ret; } #ifdef CONFIG_NFS_V4 @@ -168,8 +174,8 @@ out: struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh) { struct nfs_server *server = NFS_SB(sb); - struct nfs_fattr fattr; - struct dentry *mntroot; + struct nfs_fattr *fattr = NULL; + struct dentry *ret; struct inode *inode; int error; @@ -183,40 +189,50 @@ struct dentry *nfs4_get_root(struct super_block *sb, struct nfs_fh *mntfh) return ERR_PTR(error); } + fattr = nfs_alloc_fattr(); + if (fattr == NULL) + return ERR_PTR(-ENOMEM);; + /* get the actual root for this mount */ - error = server->nfs_client->rpc_ops->getattr(server, mntfh, &fattr); + error = server->nfs_client->rpc_ops->getattr(server, mntfh, fattr); if (error < 0) { dprintk("nfs_get_root: getattr error = %d\n", -error); - return ERR_PTR(error); + ret = ERR_PTR(error); + goto out; } - inode = nfs_fhget(sb, mntfh, &fattr); + inode = nfs_fhget(sb, mntfh, fattr); if (IS_ERR(inode)) { dprintk("nfs_get_root: get root inode failed\n"); - return ERR_CAST(inode); + ret = ERR_CAST(inode); + goto out; } error = nfs_superblock_set_dummy_root(sb, inode); - if (error != 0) - return ERR_PTR(error); + if (error != 0) { + ret = ERR_PTR(error); + goto out; + } /* root dentries normally start off anonymous and get spliced in later * if the dentry tree reaches them; however if the dentry already * exists, we'll pick it up at this point and use it as the root */ - mntroot = d_obtain_alias(inode); - if (IS_ERR(mntroot)) { + ret = d_obtain_alias(inode); + if (IS_ERR(ret)) { dprintk("nfs_get_root: get root dentry failed\n"); - return mntroot; + goto out; } - security_d_instantiate(mntroot, inode); + security_d_instantiate(ret, inode); - if (!mntroot->d_op) - mntroot->d_op = server->nfs_client->rpc_ops->dentry_ops; + if (ret->d_op == NULL) + ret->d_op = server->nfs_client->rpc_ops->dentry_ops; +out: + nfs_free_fattr(fattr); dprintk("<-- nfs4_get_root()\n"); - return mntroot; + return ret; } #endif /* CONFIG_NFS_V4 */ -- cgit v1.2.3