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314 lines
6.9 KiB
314 lines
6.9 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (c) 2012 Bryan Schumaker <[email protected]> |
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*/ |
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#include <linux/init.h> |
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#include <linux/module.h> |
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#include <linux/mount.h> |
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#include <linux/nfs4_mount.h> |
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#include <linux/nfs_fs.h> |
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#include <linux/nfs_ssc.h> |
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#include "delegation.h" |
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#include "internal.h" |
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#include "nfs4_fs.h" |
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#include "nfs4idmap.h" |
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#include "dns_resolve.h" |
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#include "pnfs.h" |
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#include "nfs.h" |
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#define NFSDBG_FACILITY NFSDBG_VFS |
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static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc); |
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static void nfs4_evict_inode(struct inode *inode); |
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static const struct super_operations nfs4_sops = { |
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.alloc_inode = nfs_alloc_inode, |
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.free_inode = nfs_free_inode, |
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.write_inode = nfs4_write_inode, |
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.drop_inode = nfs_drop_inode, |
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.statfs = nfs_statfs, |
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.evict_inode = nfs4_evict_inode, |
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.umount_begin = nfs_umount_begin, |
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.show_options = nfs_show_options, |
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.show_devname = nfs_show_devname, |
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.show_path = nfs_show_path, |
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.show_stats = nfs_show_stats, |
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}; |
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struct nfs_subversion nfs_v4 = { |
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.owner = THIS_MODULE, |
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.nfs_fs = &nfs4_fs_type, |
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.rpc_vers = &nfs_version4, |
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.rpc_ops = &nfs_v4_clientops, |
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.sops = &nfs4_sops, |
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.xattr = nfs4_xattr_handlers, |
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}; |
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static int nfs4_write_inode(struct inode *inode, struct writeback_control *wbc) |
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{ |
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int ret = nfs_write_inode(inode, wbc); |
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if (ret == 0) |
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ret = pnfs_layoutcommit_inode(inode, |
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wbc->sync_mode == WB_SYNC_ALL); |
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return ret; |
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} |
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/* |
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* Clean out any remaining NFSv4 state that might be left over due |
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* to open() calls that passed nfs_atomic_lookup, but failed to call |
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* nfs_open(). |
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*/ |
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static void nfs4_evict_inode(struct inode *inode) |
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{ |
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truncate_inode_pages_final(&inode->i_data); |
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clear_inode(inode); |
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/* If we are holding a delegation, return and free it */ |
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nfs_inode_evict_delegation(inode); |
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/* Note that above delegreturn would trigger pnfs return-on-close */ |
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pnfs_return_layout(inode); |
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pnfs_destroy_layout_final(NFS_I(inode)); |
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/* First call standard NFS clear_inode() code */ |
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nfs_clear_inode(inode); |
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nfs4_xattr_cache_zap(inode); |
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} |
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struct nfs_referral_count { |
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struct list_head list; |
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const struct task_struct *task; |
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unsigned int referral_count; |
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}; |
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static LIST_HEAD(nfs_referral_count_list); |
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static DEFINE_SPINLOCK(nfs_referral_count_list_lock); |
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static struct nfs_referral_count *nfs_find_referral_count(void) |
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{ |
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struct nfs_referral_count *p; |
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list_for_each_entry(p, &nfs_referral_count_list, list) { |
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if (p->task == current) |
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return p; |
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} |
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return NULL; |
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} |
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#define NFS_MAX_NESTED_REFERRALS 2 |
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static int nfs_referral_loop_protect(void) |
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{ |
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struct nfs_referral_count *p, *new; |
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int ret = -ENOMEM; |
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new = kmalloc(sizeof(*new), GFP_KERNEL); |
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if (!new) |
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goto out; |
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new->task = current; |
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new->referral_count = 1; |
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ret = 0; |
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spin_lock(&nfs_referral_count_list_lock); |
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p = nfs_find_referral_count(); |
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if (p != NULL) { |
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if (p->referral_count >= NFS_MAX_NESTED_REFERRALS) |
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ret = -ELOOP; |
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else |
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p->referral_count++; |
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} else { |
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list_add(&new->list, &nfs_referral_count_list); |
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new = NULL; |
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} |
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spin_unlock(&nfs_referral_count_list_lock); |
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kfree(new); |
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out: |
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return ret; |
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} |
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static void nfs_referral_loop_unprotect(void) |
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{ |
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struct nfs_referral_count *p; |
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spin_lock(&nfs_referral_count_list_lock); |
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p = nfs_find_referral_count(); |
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p->referral_count--; |
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if (p->referral_count == 0) |
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list_del(&p->list); |
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else |
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p = NULL; |
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spin_unlock(&nfs_referral_count_list_lock); |
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kfree(p); |
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} |
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static int do_nfs4_mount(struct nfs_server *server, |
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struct fs_context *fc, |
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const char *hostname, |
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const char *export_path) |
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{ |
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struct nfs_fs_context *root_ctx; |
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struct fs_context *root_fc; |
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struct vfsmount *root_mnt; |
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struct dentry *dentry; |
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size_t len; |
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int ret; |
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struct fs_parameter param = { |
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.key = "source", |
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.type = fs_value_is_string, |
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.dirfd = -1, |
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}; |
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if (IS_ERR(server)) |
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return PTR_ERR(server); |
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root_fc = vfs_dup_fs_context(fc); |
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if (IS_ERR(root_fc)) { |
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nfs_free_server(server); |
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return PTR_ERR(root_fc); |
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} |
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kfree(root_fc->source); |
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root_fc->source = NULL; |
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root_ctx = nfs_fc2context(root_fc); |
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root_ctx->internal = true; |
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root_ctx->server = server; |
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/* We leave export_path unset as it's not used to find the root. */ |
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len = strlen(hostname) + 5; |
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param.string = kmalloc(len, GFP_KERNEL); |
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if (param.string == NULL) { |
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put_fs_context(root_fc); |
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return -ENOMEM; |
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} |
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/* Does hostname needs to be enclosed in brackets? */ |
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if (strchr(hostname, ':')) |
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param.size = snprintf(param.string, len, "[%s]:/", hostname); |
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else |
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param.size = snprintf(param.string, len, "%s:/", hostname); |
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ret = vfs_parse_fs_param(root_fc, ¶m); |
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kfree(param.string); |
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if (ret < 0) { |
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put_fs_context(root_fc); |
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return ret; |
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} |
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root_mnt = fc_mount(root_fc); |
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put_fs_context(root_fc); |
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if (IS_ERR(root_mnt)) |
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return PTR_ERR(root_mnt); |
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ret = nfs_referral_loop_protect(); |
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if (ret) { |
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mntput(root_mnt); |
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return ret; |
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} |
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dentry = mount_subtree(root_mnt, export_path); |
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nfs_referral_loop_unprotect(); |
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if (IS_ERR(dentry)) |
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return PTR_ERR(dentry); |
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fc->root = dentry; |
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return 0; |
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} |
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int nfs4_try_get_tree(struct fs_context *fc) |
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{ |
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struct nfs_fs_context *ctx = nfs_fc2context(fc); |
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int err; |
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dfprintk(MOUNT, "--> nfs4_try_get_tree()\n"); |
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/* We create a mount for the server's root, walk to the requested |
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* location and then create another mount for that. |
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*/ |
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err= do_nfs4_mount(nfs4_create_server(fc), |
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fc, ctx->nfs_server.hostname, |
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ctx->nfs_server.export_path); |
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if (err) { |
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nfs_ferrorf(fc, MOUNT, "NFS4: Couldn't follow remote path"); |
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dfprintk(MOUNT, "<-- nfs4_try_get_tree() = %d [error]\n", err); |
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} else { |
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dfprintk(MOUNT, "<-- nfs4_try_get_tree() = 0\n"); |
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} |
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return err; |
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} |
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/* |
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* Create an NFS4 server record on referral traversal |
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*/ |
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int nfs4_get_referral_tree(struct fs_context *fc) |
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{ |
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struct nfs_fs_context *ctx = nfs_fc2context(fc); |
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int err; |
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dprintk("--> nfs4_referral_mount()\n"); |
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/* create a new volume representation */ |
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err = do_nfs4_mount(nfs4_create_referral_server(fc), |
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fc, ctx->nfs_server.hostname, |
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ctx->nfs_server.export_path); |
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if (err) { |
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nfs_ferrorf(fc, MOUNT, "NFS4: Couldn't follow remote path"); |
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dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = %d [error]\n", err); |
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} else { |
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dfprintk(MOUNT, "<-- nfs4_get_referral_tree() = 0\n"); |
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} |
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return err; |
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} |
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static int __init init_nfs_v4(void) |
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{ |
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int err; |
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err = nfs_dns_resolver_init(); |
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if (err) |
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goto out; |
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err = nfs_idmap_init(); |
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if (err) |
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goto out1; |
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#ifdef CONFIG_NFS_V4_2 |
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err = nfs4_xattr_cache_init(); |
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if (err) |
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goto out2; |
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#endif |
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err = nfs4_register_sysctl(); |
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if (err) |
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goto out2; |
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#ifdef CONFIG_NFS_V4_2 |
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nfs42_ssc_register_ops(); |
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#endif |
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register_nfs_version(&nfs_v4); |
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return 0; |
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out2: |
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nfs_idmap_quit(); |
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out1: |
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nfs_dns_resolver_destroy(); |
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out: |
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return err; |
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} |
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static void __exit exit_nfs_v4(void) |
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{ |
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/* Not called in the _init(), conditionally loaded */ |
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nfs4_pnfs_v3_ds_connect_unload(); |
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unregister_nfs_version(&nfs_v4); |
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#ifdef CONFIG_NFS_V4_2 |
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nfs4_xattr_cache_exit(); |
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nfs42_ssc_unregister_ops(); |
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#endif |
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nfs4_unregister_sysctl(); |
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nfs_idmap_quit(); |
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nfs_dns_resolver_destroy(); |
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} |
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MODULE_LICENSE("GPL"); |
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module_init(init_nfs_v4); |
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module_exit(exit_nfs_v4);
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