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authorManoj Naik <manoj@almaden.ibm.com>2006-06-09 09:34:28 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2006-06-09 09:34:28 -0400
commit9cdb3883c38f883436a84c2353a4cf964ff890a2 (patch)
tree7961aebf94c66d7d55bb6e7c715e99d28ad3ab9d /fs/nfs/inode.c
parent61f5164cab1f6fdf06871ea9d60fe2f912184078 (diff)
NFSv4: Ensure client submounts when following a referral
Set up mountpoint when hitting a referral on moved error by getting fs_locations. Signed-off-by: Manoj Naik <manoj@almaden.ibm.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/inode.c')
-rw-r--r--fs/nfs/inode.c270
1 files changed, 267 insertions, 3 deletions
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index ebdab885c475..0d8302e59d69 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -36,6 +36,8 @@
36#include <linux/mount.h> 36#include <linux/mount.h>
37#include <linux/nfs_idmap.h> 37#include <linux/nfs_idmap.h>
38#include <linux/vfs.h> 38#include <linux/vfs.h>
39#include <linux/inet.h>
40#include <linux/nfs_xdr.h>
39 41
40#include <asm/system.h> 42#include <asm/system.h>
41#include <asm/uaccess.h> 43#include <asm/uaccess.h>
@@ -1714,6 +1716,10 @@ struct nfs_clone_mount {
1714 const struct dentry *dentry; 1716 const struct dentry *dentry;
1715 struct nfs_fh *fh; 1717 struct nfs_fh *fh;
1716 struct nfs_fattr *fattr; 1718 struct nfs_fattr *fattr;
1719 char *hostname;
1720 char *mnt_path;
1721 struct sockaddr_in *addr;
1722 rpc_authflavor_t authflavor;
1717}; 1723};
1718 1724
1719static struct super_block *nfs_clone_generic_sb(struct nfs_clone_mount *data, 1725static struct super_block *nfs_clone_generic_sb(struct nfs_clone_mount *data,
@@ -1724,17 +1730,19 @@ static struct super_block *nfs_clone_generic_sb(struct nfs_clone_mount *data,
1724 struct nfs_server *parent = NFS_SB(data->sb); 1730 struct nfs_server *parent = NFS_SB(data->sb);
1725 struct super_block *sb = ERR_PTR(-EINVAL); 1731 struct super_block *sb = ERR_PTR(-EINVAL);
1726 void *err = ERR_PTR(-ENOMEM); 1732 void *err = ERR_PTR(-ENOMEM);
1733 char *hostname;
1727 int len; 1734 int len;
1728 1735
1729 server = kmalloc(sizeof(struct nfs_server), GFP_KERNEL); 1736 server = kmalloc(sizeof(struct nfs_server), GFP_KERNEL);
1730 if (server == NULL) 1737 if (server == NULL)
1731 goto out_err; 1738 goto out_err;
1732 memcpy(server, parent, sizeof(*server)); 1739 memcpy(server, parent, sizeof(*server));
1733 len = strlen(parent->hostname) + 1; 1740 hostname = (data->hostname != NULL) ? data->hostname : parent->hostname;
1741 len = strlen(hostname) + 1;
1734 server->hostname = kmalloc(len, GFP_KERNEL); 1742 server->hostname = kmalloc(len, GFP_KERNEL);
1735 if (server->hostname == NULL) 1743 if (server->hostname == NULL)
1736 goto free_server; 1744 goto free_server;
1737 memcpy(server->hostname, parent->hostname, len); 1745 memcpy(server->hostname, hostname, len);
1738 if (rpciod_up() != 0) 1746 if (rpciod_up() != 0)
1739 goto free_hostname; 1747 goto free_hostname;
1740 1748
@@ -2458,7 +2466,8 @@ static inline void unregister_nfs4fs(void)
2458 nfs_unregister_sysctl(); 2466 nfs_unregister_sysctl();
2459} 2467}
2460#else 2468#else
2461#define nfs4_clone_client(a,b) ERR_PTR(-EINVAL) 2469#define nfs4_fill_sb(a,b) ERR_PTR(-EINVAL)
2470#define nfs4_fill_super(a,b) ERR_PTR(-EINVAL)
2462#define nfs4_init_once(nfsi) \ 2471#define nfs4_init_once(nfsi) \
2463 do { } while (0) 2472 do { } while (0)
2464#define register_nfs4fs() (0) 2473#define register_nfs4fs() (0)
@@ -2521,6 +2530,261 @@ out:
2521 return mnt; 2530 return mnt;
2522} 2531}
2523 2532
2533/* Check if fs_root is valid */
2534static inline char *nfs4_pathname_string(struct nfs4_pathname *pathname, char *buffer, ssize_t buflen)
2535{
2536 char *end = buffer + buflen;
2537 int n;
2538
2539 *--end = '\0';
2540 buflen--;
2541
2542 n = pathname->ncomponents;
2543 while (--n >= 0) {
2544 struct nfs4_string *component = &pathname->components[n];
2545 buflen -= component->len + 1;
2546 if (buflen < 0)
2547 goto Elong;
2548 end -= component->len;
2549 memcpy(end, component->data, component->len);
2550 *--end = '/';
2551 }
2552 return end;
2553Elong:
2554 return ERR_PTR(-ENAMETOOLONG);
2555}
2556
2557/* Check if the string represents a "valid" IPv4 address */
2558static inline int valid_ipaddr4(const char *buf)
2559{
2560 int rc, count, in[4];
2561
2562 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
2563 if (rc != 4)
2564 return -EINVAL;
2565 for (count = 0; count < 4; count++) {
2566 if (in[count] > 255)
2567 return -EINVAL;
2568 }
2569 return 0;
2570}
2571
2572static struct super_block *nfs4_referral_sb(struct nfs_server *server, struct nfs_clone_mount *data)
2573{
2574 struct super_block *sb = ERR_PTR(-ENOMEM);
2575 int len;
2576
2577 len = strlen(data->mnt_path) + 1;
2578 server->mnt_path = kmalloc(len, GFP_KERNEL);
2579 if (server->mnt_path == NULL)
2580 goto err;
2581 memcpy(server->mnt_path, data->mnt_path, len);
2582 memcpy(&server->addr, data->addr, sizeof(struct sockaddr_in));
2583
2584 sb = sget(&nfs4_fs_type, nfs4_compare_super, nfs_set_super, server);
2585 if (IS_ERR(sb) || sb->s_root)
2586 goto free_path;
2587 return sb;
2588free_path:
2589 kfree(server->mnt_path);
2590err:
2591 server->mnt_path = NULL;
2592 return sb;
2593}
2594
2595static struct nfs_server *nfs4_referral_server(struct super_block *sb, struct nfs_clone_mount *data)
2596{
2597 struct nfs_server *server = NFS_SB(sb);
2598 struct rpc_timeout timeparms;
2599 int proto, timeo, retrans;
2600 void *err;
2601
2602 proto = IPPROTO_TCP;
2603 /* Since we are following a referral and there may be alternatives,
2604 set the timeouts and retries to low values */
2605 timeo = 2;
2606 retrans = 1;
2607 nfs_init_timeout_values(&timeparms, proto, timeo, retrans);
2608
2609 server->client = nfs4_create_client(server, &timeparms, proto, data->authflavor);
2610 if (IS_ERR((err = server->client)))
2611 goto out_err;
2612
2613 sb->s_time_gran = 1;
2614 sb->s_op = &nfs4_sops;
2615 err = ERR_PTR(nfs_sb_init(sb, data->authflavor));
2616 if (!IS_ERR(err))
2617 return server;
2618out_err:
2619 return (struct nfs_server *)err;
2620}
2621
2622static struct super_block *nfs_referral_nfs4_sb(struct file_system_type *fs_type,
2623 int flags, const char *dev_name, void *raw_data)
2624{
2625 struct nfs_clone_mount *data = raw_data;
2626 return nfs_clone_generic_sb(data, nfs4_referral_sb, nfs4_referral_server);
2627}
2628
2629static struct file_system_type nfs_referral_nfs4_fs_type = {
2630 .owner = THIS_MODULE,
2631 .name = "nfs4",
2632 .get_sb = nfs_referral_nfs4_sb,
2633 .kill_sb = nfs4_kill_super,
2634 .fs_flags = FS_ODD_RENAME|FS_REVAL_DOT|FS_BINARY_MOUNTDATA,
2635};
2636
2637/**
2638 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
2639 * @mnt_parent - mountpoint of parent directory
2640 * @dentry - parent directory
2641 * @fspath - fs path returned in fs_locations
2642 * @mntpath - mount path to new server
2643 * @hostname - hostname of new server
2644 * @addr - host addr of new server
2645 *
2646 */
2647struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
2648 const struct dentry *dentry, struct nfs4_fs_locations *locations)
2649{
2650 struct vfsmount *mnt = ERR_PTR(-ENOENT);
2651 struct nfs_clone_mount mountdata = {
2652 .sb = mnt_parent->mnt_sb,
2653 .dentry = dentry,
2654 .authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor,
2655 };
2656 char *page, *page2;
2657 char *path, *fs_path;
2658 char *devname;
2659 int loc, s;
2660
2661 if (locations == NULL || locations->nlocations <= 0)
2662 goto out;
2663
2664 dprintk("%s: referral at %s/%s\n", __FUNCTION__,
2665 dentry->d_parent->d_name.name, dentry->d_name.name);
2666
2667 /* Ensure fs path is a prefix of current dentry path */
2668 page = (char *) __get_free_page(GFP_USER);
2669 if (page == NULL)
2670 goto out;
2671 page2 = (char *) __get_free_page(GFP_USER);
2672 if (page2 == NULL)
2673 goto out;
2674
2675 path = nfs4_path(dentry, page, PAGE_SIZE);
2676 if (IS_ERR(path))
2677 goto out_free;
2678
2679 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
2680 if (IS_ERR(fs_path))
2681 goto out_free;
2682
2683 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
2684 dprintk("%s: path %s does not begin with fsroot %s\n", __FUNCTION__, path, fs_path);
2685 goto out_free;
2686 }
2687
2688 devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE);
2689 if (IS_ERR(devname)) {
2690 mnt = (struct vfsmount *)devname;
2691 goto out_free;
2692 }
2693
2694 loc = 0;
2695 while (loc < locations->nlocations && IS_ERR(mnt)) {
2696 struct nfs4_fs_location *location = &locations->locations[loc];
2697 char *mnt_path;
2698
2699 if (location == NULL || location->nservers <= 0 ||
2700 location->rootpath.ncomponents == 0) {
2701 loc++;
2702 continue;
2703 }
2704
2705 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
2706 if (IS_ERR(mnt_path)) {
2707 loc++;
2708 continue;
2709 }
2710 mountdata.mnt_path = mnt_path;
2711
2712 s = 0;
2713 while (s < location->nservers) {
2714 struct sockaddr_in addr = {};
2715
2716 if (location->servers[s].len <= 0 ||
2717 valid_ipaddr4(location->servers[s].data) < 0) {
2718 s++;
2719 continue;
2720 }
2721
2722 mountdata.hostname = location->servers[s].data;
2723 addr.sin_addr.s_addr = in_aton(mountdata.hostname);
2724 addr.sin_family = AF_INET;
2725 addr.sin_port = htons(NFS_PORT);
2726 mountdata.addr = &addr;
2727
2728 mnt = vfs_kern_mount(&nfs_referral_nfs4_fs_type, 0, devname, &mountdata);
2729 if (!IS_ERR(mnt)) {
2730 break;
2731 }
2732 s++;
2733 }
2734 loc++;
2735 }
2736
2737out_free:
2738 free_page((unsigned long)page);
2739 free_page((unsigned long)page2);
2740out:
2741 dprintk("%s: done\n", __FUNCTION__);
2742 return mnt;
2743}
2744
2745/*
2746 * nfs_do_refmount - handle crossing a referral on server
2747 * @dentry - dentry of referral
2748 * @nd - nameidata info
2749 *
2750 */
2751struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry)
2752{
2753 struct vfsmount *mnt = ERR_PTR(-ENOENT);
2754 struct dentry *parent;
2755 struct nfs4_fs_locations *fs_locations = NULL;
2756 struct page *page;
2757 int err;
2758
2759 /* BUG_ON(IS_ROOT(dentry)); */
2760 dprintk("%s: enter\n", __FUNCTION__);
2761
2762 page = alloc_page(GFP_KERNEL);
2763 if (page == NULL)
2764 goto out;
2765
2766 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
2767 if (fs_locations == NULL)
2768 goto out_free;
2769
2770 /* Get locations */
2771 parent = dget_parent(dentry);
2772 dprintk("%s: getting locations for %s/%s\n", __FUNCTION__, parent->d_name.name, dentry->d_name.name);
2773 err = nfs4_proc_fs_locations(parent->d_inode, dentry, fs_locations, page);
2774 dput(parent);
2775 if (err != 0 || fs_locations->nlocations <= 0 ||
2776 fs_locations->fs_path.ncomponents <= 0)
2777 goto out_free;
2778
2779 mnt = nfs_follow_referral(mnt_parent, dentry, fs_locations);
2780out_free:
2781 __free_page(page);
2782 kfree(fs_locations);
2783out:
2784 dprintk("%s: done\n", __FUNCTION__);
2785 return mnt;
2786}
2787
2524extern int nfs_init_nfspagecache(void); 2788extern int nfs_init_nfspagecache(void);
2525extern void nfs_destroy_nfspagecache(void); 2789extern void nfs_destroy_nfspagecache(void);
2526extern int nfs_init_readpagecache(void); 2790extern int nfs_init_readpagecache(void);