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author | Jeff Garzik <jeff@garzik.org> | 2006-09-24 01:52:47 -0400 |
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committer | Jeff Garzik <jeff@garzik.org> | 2006-09-24 01:52:47 -0400 |
commit | 23930fa1cebfea6f79881c588ccd1b0781e49e3f (patch) | |
tree | 36d29e3f83661c4f5f45b6f74ac0d5f9886867a8 /fs/nfs/getroot.c | |
parent | 36b35a5be0e4b406acd816e2122d153e875105be (diff) | |
parent | 4f5537de7c1531398e84e18a24f667e49cc94208 (diff) | |
download | kernel_samsung_smdk4412-23930fa1cebfea6f79881c588ccd1b0781e49e3f.zip kernel_samsung_smdk4412-23930fa1cebfea6f79881c588ccd1b0781e49e3f.tar.gz kernel_samsung_smdk4412-23930fa1cebfea6f79881c588ccd1b0781e49e3f.tar.bz2 |
Merge branch 'master' into upstream
Diffstat (limited to 'fs/nfs/getroot.c')
-rw-r--r-- | fs/nfs/getroot.c | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c new file mode 100644 index 0000000..76b08ae --- /dev/null +++ b/fs/nfs/getroot.c @@ -0,0 +1,311 @@ +/* getroot.c: get the root dentry for an NFS mount + * + * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/init.h> + +#include <linux/time.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <linux/stat.h> +#include <linux/errno.h> +#include <linux/unistd.h> +#include <linux/sunrpc/clnt.h> +#include <linux/sunrpc/stats.h> +#include <linux/nfs_fs.h> +#include <linux/nfs_mount.h> +#include <linux/nfs4_mount.h> +#include <linux/lockd/bind.h> +#include <linux/smp_lock.h> +#include <linux/seq_file.h> +#include <linux/mount.h> +#include <linux/nfs_idmap.h> +#include <linux/vfs.h> +#include <linux/namei.h> +#include <linux/namespace.h> +#include <linux/security.h> + +#include <asm/system.h> +#include <asm/uaccess.h> + +#include "nfs4_fs.h" +#include "delegation.h" +#include "internal.h" + +#define NFSDBG_FACILITY NFSDBG_CLIENT +#define NFS_PARANOIA 1 + +/* + * get an NFS2/NFS3 root dentry from the root filehandle + */ +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 inode *inode; + int error; + + /* create a dummy root dentry with dummy inode for this superblock */ + if (!sb->s_root) { + struct nfs_fh dummyfh; + struct dentry *root; + struct inode *iroot; + + memset(&dummyfh, 0, sizeof(dummyfh)); + memset(&fattr, 0, sizeof(fattr)); + nfs_fattr_init(&fattr); + fattr.valid = NFS_ATTR_FATTR; + fattr.type = NFDIR; + fattr.mode = S_IFDIR | S_IRUSR | S_IWUSR; + fattr.nlink = 2; + + iroot = nfs_fhget(sb, &dummyfh, &fattr); + if (IS_ERR(iroot)) + return ERR_PTR(PTR_ERR(iroot)); + + root = d_alloc_root(iroot); + if (!root) { + iput(iroot); + return ERR_PTR(-ENOMEM); + } + + sb->s_root = root; + } + + /* get the actual root for this mount */ + fsinfo.fattr = &fattr; + + 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); + } + + inode = nfs_fhget(sb, mntfh, fsinfo.fattr); + if (IS_ERR(inode)) { + dprintk("nfs_get_root: get root inode failed\n"); + return ERR_PTR(PTR_ERR(inode)); + } + + /* 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_alloc_anon(inode); + if (!mntroot) { + iput(inode); + dprintk("nfs_get_root: get root dentry failed\n"); + return ERR_PTR(-ENOMEM); + } + + security_d_instantiate(mntroot, inode); + + if (!mntroot->d_op) + mntroot->d_op = server->nfs_client->rpc_ops->dentry_ops; + + return mntroot; +} + +#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) +{ + struct nfs_fsinfo fsinfo; + struct nfs_fattr fattr; + struct nfs_fh lastfh; + struct qstr name; + int ret; + //int referral_count = 0; + + dprintk("--> nfs4_path_walk(,,%s)\n", path); + + fsinfo.fattr = &fattr; + nfs_fattr_init(&fattr); + + if (*path++ != '/') { + dprintk("nfs4_get_root: Path does not begin with a slash\n"); + return -EINVAL; + } + + /* 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; + } + + if (fattr.type != NFDIR) { + printk(KERN_ERR "nfs4_get_root:" + " getroot encountered non-directory\n"); + return -ENOTDIR; + } + + if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL) { + printk(KERN_ERR "nfs4_get_root:" + " getroot obtained referral\n"); + return -EREMOTE; + } + +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; + +eat_dot_dir: + while (*path == '/') + path++; + + if (path[0] == '.' && (path[1] == '/' || !path[1])) { + path += 2; + goto eat_dot_dir; + } + + 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 (fattr.type != NFDIR) { + printk(KERN_ERR "nfs4_get_root:" + " lookupfh encountered non-directory\n"); + return -ENOTDIR; + } + + 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; +} + +/* + * get an NFS4 root dentry from the root filehandle + */ +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 inode *inode; + int error; + + dprintk("--> nfs4_get_root()\n"); + + /* create a dummy root dentry with dummy inode for this superblock */ + if (!sb->s_root) { + struct nfs_fh dummyfh; + struct dentry *root; + struct inode *iroot; + + memset(&dummyfh, 0, sizeof(dummyfh)); + memset(&fattr, 0, sizeof(fattr)); + nfs_fattr_init(&fattr); + fattr.valid = NFS_ATTR_FATTR; + fattr.type = NFDIR; + fattr.mode = S_IFDIR | S_IRUSR | S_IWUSR; + fattr.nlink = 2; + + iroot = nfs_fhget(sb, &dummyfh, &fattr); + if (IS_ERR(iroot)) + return ERR_PTR(PTR_ERR(iroot)); + + root = d_alloc_root(iroot); + if (!root) { + iput(iroot); + return ERR_PTR(-ENOMEM); + } + + sb->s_root = root; + } + + /* get the info about the server and filesystem */ + error = nfs4_server_capabilities(server, mntfh); + if (error < 0) { + dprintk("nfs_get_root: getcaps error = %d\n", + -error); + return ERR_PTR(error); + } + + /* get the actual root for this mount */ + 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); + } + + inode = nfs_fhget(sb, mntfh, &fattr); + if (IS_ERR(inode)) { + dprintk("nfs_get_root: get root inode failed\n"); + return ERR_PTR(PTR_ERR(inode)); + } + + /* 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_alloc_anon(inode); + if (!mntroot) { + iput(inode); + dprintk("nfs_get_root: get root dentry failed\n"); + return ERR_PTR(-ENOMEM); + } + + security_d_instantiate(mntroot, inode); + + if (!mntroot->d_op) + mntroot->d_op = server->nfs_client->rpc_ops->dentry_ops; + + dprintk("<-- nfs4_get_root()\n"); + return mntroot; +} + +#endif /* CONFIG_NFS_V4 */ |