| /* NFS filesystem cache interface |
| * |
| * Copyright (C) 2008 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 Licence |
| * as published by the Free Software Foundation; either version |
| * 2 of the Licence, or (at your option) any later version. |
| */ |
| |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/sched.h> |
| #include <linux/mm.h> |
| #include <linux/nfs_fs.h> |
| #include <linux/nfs_fs_sb.h> |
| #include <linux/in6.h> |
| #include <linux/seq_file.h> |
| |
| #include "internal.h" |
| #include "fscache.h" |
| |
| #define NFSDBG_FACILITY NFSDBG_FSCACHE |
| |
| static struct rb_root nfs_fscache_keys = RB_ROOT; |
| static DEFINE_SPINLOCK(nfs_fscache_keys_lock); |
| |
| /* |
| * Get the per-client index cookie for an NFS client if the appropriate mount |
| * flag was set |
| * - We always try and get an index cookie for the client, but get filehandle |
| * cookies on a per-superblock basis, depending on the mount flags |
| */ |
| void nfs_fscache_get_client_cookie(struct nfs_client *clp) |
| { |
| /* create a cache index for looking up filehandles */ |
| clp->fscache = fscache_acquire_cookie(nfs_fscache_netfs.primary_index, |
| &nfs_fscache_server_index_def, |
| clp); |
| dfprintk(FSCACHE, "NFS: get client cookie (0x%p/0x%p)\n", |
| clp, clp->fscache); |
| } |
| |
| /* |
| * Dispose of a per-client cookie |
| */ |
| void nfs_fscache_release_client_cookie(struct nfs_client *clp) |
| { |
| dfprintk(FSCACHE, "NFS: releasing client cookie (0x%p/0x%p)\n", |
| clp, clp->fscache); |
| |
| fscache_relinquish_cookie(clp->fscache, 0); |
| clp->fscache = NULL; |
| } |
| |
| /* |
| * Get the cache cookie for an NFS superblock. We have to handle |
| * uniquification here because the cache doesn't do it for us. |
| */ |
| void nfs_fscache_get_super_cookie(struct super_block *sb, |
| struct nfs_parsed_mount_data *data) |
| { |
| struct nfs_fscache_key *key, *xkey; |
| struct nfs_server *nfss = NFS_SB(sb); |
| struct rb_node **p, *parent; |
| const char *uniq = data->fscache_uniq ?: ""; |
| int diff, ulen; |
| |
| ulen = strlen(uniq); |
| key = kzalloc(sizeof(*key) + ulen, GFP_KERNEL); |
| if (!key) |
| return; |
| |
| key->nfs_client = nfss->nfs_client; |
| key->key.super.s_flags = sb->s_flags & NFS_MS_MASK; |
| key->key.nfs_server.flags = nfss->flags; |
| key->key.nfs_server.rsize = nfss->rsize; |
| key->key.nfs_server.wsize = nfss->wsize; |
| key->key.nfs_server.acregmin = nfss->acregmin; |
| key->key.nfs_server.acregmax = nfss->acregmax; |
| key->key.nfs_server.acdirmin = nfss->acdirmin; |
| key->key.nfs_server.acdirmax = nfss->acdirmax; |
| key->key.nfs_server.fsid = nfss->fsid; |
| key->key.rpc_auth.au_flavor = nfss->client->cl_auth->au_flavor; |
| |
| key->key.uniq_len = ulen; |
| memcpy(key->key.uniquifier, uniq, ulen); |
| |
| spin_lock(&nfs_fscache_keys_lock); |
| p = &nfs_fscache_keys.rb_node; |
| parent = NULL; |
| while (*p) { |
| parent = *p; |
| xkey = rb_entry(parent, struct nfs_fscache_key, node); |
| |
| if (key->nfs_client < xkey->nfs_client) |
| goto go_left; |
| if (key->nfs_client > xkey->nfs_client) |
| goto go_right; |
| |
| diff = memcmp(&key->key, &xkey->key, sizeof(key->key)); |
| if (diff < 0) |
| goto go_left; |
| if (diff > 0) |
| goto go_right; |
| |
| if (key->key.uniq_len == 0) |
| goto non_unique; |
| diff = memcmp(key->key.uniquifier, |
| xkey->key.uniquifier, |
| key->key.uniq_len); |
| if (diff < 0) |
| goto go_left; |
| if (diff > 0) |
| goto go_right; |
| goto non_unique; |
| |
| go_left: |
| p = &(*p)->rb_left; |
| continue; |
| go_right: |
| p = &(*p)->rb_right; |
| } |
| |
| rb_link_node(&key->node, parent, p); |
| rb_insert_color(&key->node, &nfs_fscache_keys); |
| spin_unlock(&nfs_fscache_keys_lock); |
| nfss->fscache_key = key; |
| |
| /* create a cache index for looking up filehandles */ |
| nfss->fscache = fscache_acquire_cookie(nfss->nfs_client->fscache, |
| &nfs_fscache_super_index_def, |
| nfss); |
| dfprintk(FSCACHE, "NFS: get superblock cookie (0x%p/0x%p)\n", |
| nfss, nfss->fscache); |
| return; |
| |
| non_unique: |
| spin_unlock(&nfs_fscache_keys_lock); |
| kfree(key); |
| nfss->fscache_key = NULL; |
| nfss->fscache = NULL; |
| printk(KERN_WARNING "NFS:" |
| " Cache request denied due to non-unique superblock keys\n"); |
| } |
| |
| /* |
| * release a per-superblock cookie |
| */ |
| void nfs_fscache_release_super_cookie(struct super_block *sb) |
| { |
| struct nfs_server *nfss = NFS_SB(sb); |
| |
| dfprintk(FSCACHE, "NFS: releasing superblock cookie (0x%p/0x%p)\n", |
| nfss, nfss->fscache); |
| |
| fscache_relinquish_cookie(nfss->fscache, 0); |
| nfss->fscache = NULL; |
| |
| if (nfss->fscache_key) { |
| spin_lock(&nfs_fscache_keys_lock); |
| rb_erase(&nfss->fscache_key->node, &nfs_fscache_keys); |
| spin_unlock(&nfs_fscache_keys_lock); |
| kfree(nfss->fscache_key); |
| nfss->fscache_key = NULL; |
| } |
| } |