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authorTrond Myklebust <Trond.Myklebust@netapp.com>2006-06-09 09:34:19 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2006-06-09 09:34:19 -0400
commit55a975937d40cac582e981ddc8ed783b3dcc043c (patch)
tree13507eaebdab5e9c9dd615fe373ec6c0ddcbade4 /fs/nfs/inode.c
parent8b4bdcf8995dd92b23d2ec22b32aee8fbbb50e1c (diff)
NFS: Ensure the client submounts, when it crosses a server mountpoint.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/inode.c')
-rw-r--r--fs/nfs/inode.c303
1 files changed, 300 insertions, 3 deletions
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 1a809f6f8989..47167ab64f5b 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -221,6 +221,14 @@ nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
221 return nfs_block_bits(bsize, nrbitsp); 221 return nfs_block_bits(bsize, nrbitsp);
222} 222}
223 223
224static inline void
225nfs_super_set_maxbytes(struct super_block *sb, __u64 maxfilesize)
226{
227 sb->s_maxbytes = (loff_t)maxfilesize;
228 if (sb->s_maxbytes > MAX_LFS_FILESIZE || sb->s_maxbytes <= 0)
229 sb->s_maxbytes = MAX_LFS_FILESIZE;
230}
231
224/* 232/*
225 * Obtain the root inode of the file system. 233 * Obtain the root inode of the file system.
226 */ 234 */
@@ -331,9 +339,7 @@ nfs_sb_init(struct super_block *sb, rpc_authflavor_t authflavor)
331 } 339 }
332 server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD; 340 server->backing_dev_info.ra_pages = server->rpages * NFS_MAX_READAHEAD;
333 341
334 sb->s_maxbytes = fsinfo.maxfilesize; 342 nfs_super_set_maxbytes(sb, fsinfo.maxfilesize);
335 if (sb->s_maxbytes > MAX_LFS_FILESIZE)
336 sb->s_maxbytes = MAX_LFS_FILESIZE;
337 343
338 server->client->cl_intr = (server->flags & NFS_MOUNT_INTR) ? 1 : 0; 344 server->client->cl_intr = (server->flags & NFS_MOUNT_INTR) ? 1 : 0;
339 server->client->cl_softrtry = (server->flags & NFS_MOUNT_SOFT) ? 1 : 0; 345 server->client->cl_softrtry = (server->flags & NFS_MOUNT_SOFT) ? 1 : 0;
@@ -877,6 +883,11 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
877 if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS) 883 if (nfs_server_capable(inode, NFS_CAP_READDIRPLUS)
878 && fattr->size <= NFS_LIMIT_READDIRPLUS) 884 && fattr->size <= NFS_LIMIT_READDIRPLUS)
879 set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode)); 885 set_bit(NFS_INO_ADVISE_RDPLUS, &NFS_FLAGS(inode));
886 /* Deal with crossing mountpoints */
887 if (!nfs_fsid_equal(&NFS_SB(sb)->fsid, &fattr->fsid)) {
888 inode->i_op = &nfs_mountpoint_inode_operations;
889 inode->i_fop = NULL;
890 }
880 } else if (S_ISLNK(inode->i_mode)) 891 } else if (S_ISLNK(inode->i_mode))
881 inode->i_op = &nfs_symlink_inode_operations; 892 inode->i_op = &nfs_symlink_inode_operations;
882 else 893 else
@@ -1650,6 +1661,141 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr)
1650 * File system information 1661 * File system information
1651 */ 1662 */
1652 1663
1664/*
1665 * nfs_path - reconstruct the path given an arbitrary dentry
1666 * @base - arbitrary string to prepend to the path
1667 * @dentry - pointer to dentry
1668 * @buffer - result buffer
1669 * @buflen - length of buffer
1670 *
1671 * Helper function for constructing the path from the
1672 * root dentry to an arbitrary hashed dentry.
1673 *
1674 * This is mainly for use in figuring out the path on the
1675 * server side when automounting on top of an existing partition.
1676 */
1677static char *nfs_path(const char *base, const struct dentry *dentry,
1678 char *buffer, ssize_t buflen)
1679{
1680 char *end = buffer+buflen;
1681 int namelen;
1682
1683 *--end = '\0';
1684 buflen--;
1685 spin_lock(&dcache_lock);
1686 while (!IS_ROOT(dentry)) {
1687 namelen = dentry->d_name.len;
1688 buflen -= namelen + 1;
1689 if (buflen < 0)
1690 goto Elong;
1691 end -= namelen;
1692 memcpy(end, dentry->d_name.name, namelen);
1693 *--end = '/';
1694 dentry = dentry->d_parent;
1695 }
1696 spin_unlock(&dcache_lock);
1697 namelen = strlen(base);
1698 /* Strip off excess slashes in base string */
1699 while (namelen > 0 && base[namelen - 1] == '/')
1700 namelen--;
1701 buflen -= namelen;
1702 if (buflen < 0)
1703 goto Elong;
1704 end -= namelen;
1705 memcpy(end, base, namelen);
1706 return end;
1707Elong:
1708 return ERR_PTR(-ENAMETOOLONG);
1709}
1710
1711struct nfs_clone_mount {
1712 const struct super_block *sb;
1713 const struct dentry *dentry;
1714 struct nfs_fh *fh;
1715 struct nfs_fattr *fattr;
1716};
1717
1718static struct super_block *nfs_clone_generic_sb(struct nfs_clone_mount *data,
1719 struct super_block *(*clone_client)(struct nfs_server *, struct nfs_clone_mount *))
1720{
1721 struct nfs_server *server;
1722 struct nfs_server *parent = NFS_SB(data->sb);
1723 struct super_block *sb = ERR_PTR(-EINVAL);
1724 void *err = ERR_PTR(-ENOMEM);
1725 struct inode *root_inode;
1726 struct nfs_fsinfo fsinfo;
1727 int len;
1728
1729 server = kmalloc(sizeof(struct nfs_server), GFP_KERNEL);
1730 if (server == NULL)
1731 goto out_err;
1732 memcpy(server, parent, sizeof(*server));
1733 len = strlen(parent->hostname) + 1;
1734 server->hostname = kmalloc(len, GFP_KERNEL);
1735 if (server->hostname == NULL)
1736 goto free_server;
1737 memcpy(server->hostname, parent->hostname, len);
1738 server->fsid = data->fattr->fsid;
1739 nfs_copy_fh(&server->fh, data->fh);
1740 if (rpciod_up() != 0)
1741 goto free_hostname;
1742
1743 sb = clone_client(server, data);
1744 if (IS_ERR((err = sb)) || sb->s_root)
1745 goto kill_rpciod;
1746
1747 sb->s_op = data->sb->s_op;
1748 sb->s_blocksize = data->sb->s_blocksize;
1749 sb->s_blocksize_bits = data->sb->s_blocksize_bits;
1750 sb->s_maxbytes = data->sb->s_maxbytes;
1751
1752 server->client_sys = server->client_acl = ERR_PTR(-EINVAL);
1753 err = ERR_PTR(-ENOMEM);
1754 server->io_stats = nfs_alloc_iostats();
1755 if (server->io_stats == NULL)
1756 goto out_deactivate;
1757
1758 server->client = rpc_clone_client(parent->client);
1759 if (IS_ERR((err = server->client)))
1760 goto out_deactivate;
1761 if (!IS_ERR(parent->client_sys)) {
1762 server->client_sys = rpc_clone_client(parent->client_sys);
1763 if (IS_ERR((err = server->client_sys)))
1764 goto out_deactivate;
1765 }
1766 if (!IS_ERR(parent->client_acl)) {
1767 server->client_acl = rpc_clone_client(parent->client_acl);
1768 if (IS_ERR((err = server->client_acl)))
1769 goto out_deactivate;
1770 }
1771 root_inode = nfs_fhget(sb, data->fh, data->fattr);
1772 if (!root_inode)
1773 goto out_deactivate;
1774 sb->s_root = d_alloc_root(root_inode);
1775 if (!sb->s_root)
1776 goto out_put_root;
1777 fsinfo.fattr = data->fattr;
1778 if (NFS_PROTO(root_inode)->fsinfo(server, data->fh, &fsinfo) == 0)
1779 nfs_super_set_maxbytes(sb, fsinfo.maxfilesize);
1780 sb->s_root->d_op = server->rpc_ops->dentry_ops;
1781 sb->s_flags |= MS_ACTIVE;
1782 return sb;
1783out_put_root:
1784 iput(root_inode);
1785out_deactivate:
1786 up_write(&sb->s_umount);
1787 deactivate_super(sb);
1788 return (struct super_block *)err;
1789kill_rpciod:
1790 rpciod_down();
1791free_hostname:
1792 kfree(server->hostname);
1793free_server:
1794 kfree(server);
1795out_err:
1796 return (struct super_block *)err;
1797}
1798
1653static int nfs_set_super(struct super_block *s, void *data) 1799static int nfs_set_super(struct super_block *s, void *data)
1654{ 1800{
1655 s->s_fs_info = data; 1801 s->s_fs_info = data;
@@ -1807,6 +1953,31 @@ static struct file_system_type nfs_fs_type = {
1807 .fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA, 1953 .fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
1808}; 1954};
1809 1955
1956static struct super_block *nfs_clone_client(struct nfs_server *server, struct nfs_clone_mount *data)
1957{
1958 struct super_block *sb;
1959
1960 sb = sget(&nfs_fs_type, nfs_compare_super, nfs_set_super, server);
1961 if (!IS_ERR(sb) && sb->s_root == NULL && !(server->flags & NFS_MOUNT_NONLM))
1962 lockd_up();
1963 return sb;
1964}
1965
1966static struct super_block *nfs_clone_nfs_sb(struct file_system_type *fs_type,
1967 int flags, const char *dev_name, void *raw_data)
1968{
1969 struct nfs_clone_mount *data = raw_data;
1970 return nfs_clone_generic_sb(data, nfs_clone_client);
1971}
1972
1973static struct file_system_type clone_nfs_fs_type = {
1974 .owner = THIS_MODULE,
1975 .name = "nfs",
1976 .get_sb = nfs_clone_nfs_sb,
1977 .kill_sb = nfs_kill_super,
1978 .fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
1979};
1980
1810#ifdef CONFIG_NFS_V4 1981#ifdef CONFIG_NFS_V4
1811 1982
1812static void nfs4_clear_inode(struct inode *); 1983static void nfs4_clear_inode(struct inode *);
@@ -2156,6 +2327,75 @@ static int param_set_idmap_timeout(const char *val, struct kernel_param *kp)
2156module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int, 2327module_param_call(idmap_cache_timeout, param_set_idmap_timeout, param_get_int,
2157 &nfs_idmap_cache_timeout, 0644); 2328 &nfs_idmap_cache_timeout, 0644);
2158 2329
2330/* Constructs the SERVER-side path */
2331static inline char *nfs4_path(const struct dentry *dentry, char *buffer, ssize_t buflen)
2332{
2333 return nfs_path(NFS_SB(dentry->d_sb)->mnt_path, dentry, buffer, buflen);
2334}
2335
2336static inline char *nfs4_dup_path(const struct dentry *dentry)
2337{
2338 char *page = (char *) __get_free_page(GFP_USER);
2339 char *path;
2340
2341 path = nfs4_path(dentry, page, PAGE_SIZE);
2342 if (!IS_ERR(path)) {
2343 int len = PAGE_SIZE + page - path;
2344 char *tmp = path;
2345
2346 path = kmalloc(len, GFP_KERNEL);
2347 if (path)
2348 memcpy(path, tmp, len);
2349 else
2350 path = ERR_PTR(-ENOMEM);
2351 }
2352 free_page((unsigned long)page);
2353 return path;
2354}
2355
2356static struct super_block *nfs4_clone_client(struct nfs_server *server, struct nfs_clone_mount *data)
2357{
2358 const struct dentry *dentry = data->dentry;
2359 struct nfs4_client *clp = server->nfs4_state;
2360 struct super_block *sb;
2361
2362 server->mnt_path = nfs4_dup_path(dentry);
2363 if (IS_ERR(server->mnt_path)) {
2364 sb = (struct super_block *)server->mnt_path;
2365 goto err;
2366 }
2367 sb = sget(&nfs4_fs_type, nfs4_compare_super, nfs_set_super, server);
2368 if (IS_ERR(sb) || sb->s_root)
2369 goto free_path;
2370 nfs4_server_capabilities(server, &server->fh);
2371
2372 down_write(&clp->cl_sem);
2373 atomic_inc(&clp->cl_count);
2374 list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
2375 up_write(&clp->cl_sem);
2376 return sb;
2377free_path:
2378 kfree(server->mnt_path);
2379err:
2380 server->mnt_path = NULL;
2381 return sb;
2382}
2383
2384static struct super_block *nfs_clone_nfs4_sb(struct file_system_type *fs_type,
2385 int flags, const char *dev_name, void *raw_data)
2386{
2387 struct nfs_clone_mount *data = raw_data;
2388 return nfs_clone_generic_sb(data, nfs4_clone_client);
2389}
2390
2391static struct file_system_type clone_nfs4_fs_type = {
2392 .owner = THIS_MODULE,
2393 .name = "nfs",
2394 .get_sb = nfs_clone_nfs4_sb,
2395 .kill_sb = nfs4_kill_super,
2396 .fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
2397};
2398
2159#define nfs4_init_once(nfsi) \ 2399#define nfs4_init_once(nfsi) \
2160 do { \ 2400 do { \
2161 INIT_LIST_HEAD(&(nfsi)->open_states); \ 2401 INIT_LIST_HEAD(&(nfsi)->open_states); \
@@ -2183,12 +2423,69 @@ static inline void unregister_nfs4fs(void)
2183 nfs_unregister_sysctl(); 2423 nfs_unregister_sysctl();
2184} 2424}
2185#else 2425#else
2426#define nfs4_clone_client(a,b) ERR_PTR(-EINVAL)
2186#define nfs4_init_once(nfsi) \ 2427#define nfs4_init_once(nfsi) \
2187 do { } while (0) 2428 do { } while (0)
2188#define register_nfs4fs() (0) 2429#define register_nfs4fs() (0)
2189#define unregister_nfs4fs() 2430#define unregister_nfs4fs()
2190#endif 2431#endif
2191 2432
2433static inline char *nfs_devname(const struct vfsmount *mnt_parent,
2434 const struct dentry *dentry,
2435 char *buffer, ssize_t buflen)
2436{
2437 return nfs_path(mnt_parent->mnt_devname, dentry, buffer, buflen);
2438}
2439
2440/**
2441 * nfs_do_submount - set up mountpoint when crossing a filesystem boundary
2442 * @mnt_parent - mountpoint of parent directory
2443 * @dentry - parent directory
2444 * @fh - filehandle for new root dentry
2445 * @fattr - attributes for new root inode
2446 *
2447 */
2448struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent,
2449 const struct dentry *dentry, struct nfs_fh *fh,
2450 struct nfs_fattr *fattr)
2451{
2452 struct nfs_clone_mount mountdata = {
2453 .sb = mnt_parent->mnt_sb,
2454 .dentry = dentry,
2455 .fh = fh,
2456 .fattr = fattr,
2457 };
2458 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
2459 char *page = (char *) __get_free_page(GFP_USER);
2460 char *devname;
2461
2462 dprintk("%s: submounting on %s/%s\n", __FUNCTION__,
2463 dentry->d_parent->d_name.name,
2464 dentry->d_name.name);
2465 if (page == NULL)
2466 goto out;
2467 devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE);
2468 mnt = (struct vfsmount *)devname;
2469 if (IS_ERR(devname))
2470 goto free_page;
2471 switch (NFS_SB(mnt_parent->mnt_sb)->rpc_ops->version) {
2472 case 2:
2473 case 3:
2474 mnt = vfs_kern_mount(&clone_nfs_fs_type, 0, devname, &mountdata);
2475 break;
2476 case 4:
2477 mnt = vfs_kern_mount(&clone_nfs4_fs_type, 0, devname, &mountdata);
2478 break;
2479 default:
2480 BUG();
2481 }
2482free_page:
2483 free_page((unsigned long)page);
2484out:
2485 dprintk("%s: done\n", __FUNCTION__);
2486 return mnt;
2487}
2488
2192extern int nfs_init_nfspagecache(void); 2489extern int nfs_init_nfspagecache(void);
2193extern void nfs_destroy_nfspagecache(void); 2490extern void nfs_destroy_nfspagecache(void);
2194extern int nfs_init_readpagecache(void); 2491extern int nfs_init_readpagecache(void);