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520 lines
14 KiB
520 lines
14 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* NFS filesystem cache interface |
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* |
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* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved. |
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* Written by David Howells ([email protected]) |
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*/ |
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|
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#include <linux/init.h> |
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#include <linux/kernel.h> |
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#include <linux/sched.h> |
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#include <linux/mm.h> |
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#include <linux/nfs_fs.h> |
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#include <linux/nfs_fs_sb.h> |
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#include <linux/in6.h> |
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#include <linux/seq_file.h> |
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#include <linux/slab.h> |
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#include <linux/iversion.h> |
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#include "internal.h" |
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#include "iostat.h" |
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#include "fscache.h" |
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#define NFSDBG_FACILITY NFSDBG_FSCACHE |
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static struct rb_root nfs_fscache_keys = RB_ROOT; |
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static DEFINE_SPINLOCK(nfs_fscache_keys_lock); |
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|
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/* |
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* Layout of the key for an NFS server cache object. |
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*/ |
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struct nfs_server_key { |
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struct { |
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uint16_t nfsversion; /* NFS protocol version */ |
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uint32_t minorversion; /* NFSv4 minor version */ |
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uint16_t family; /* address family */ |
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__be16 port; /* IP port */ |
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} hdr; |
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union { |
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struct in_addr ipv4_addr; /* IPv4 address */ |
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struct in6_addr ipv6_addr; /* IPv6 address */ |
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}; |
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} __packed; |
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|
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/* |
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* Get the per-client index cookie for an NFS client if the appropriate mount |
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* flag was set |
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* - We always try and get an index cookie for the client, but get filehandle |
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* cookies on a per-superblock basis, depending on the mount flags |
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*/ |
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void nfs_fscache_get_client_cookie(struct nfs_client *clp) |
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{ |
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const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &clp->cl_addr; |
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const struct sockaddr_in *sin = (struct sockaddr_in *) &clp->cl_addr; |
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struct nfs_server_key key; |
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uint16_t len = sizeof(key.hdr); |
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memset(&key, 0, sizeof(key)); |
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key.hdr.nfsversion = clp->rpc_ops->version; |
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key.hdr.minorversion = clp->cl_minorversion; |
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key.hdr.family = clp->cl_addr.ss_family; |
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switch (clp->cl_addr.ss_family) { |
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case AF_INET: |
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key.hdr.port = sin->sin_port; |
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key.ipv4_addr = sin->sin_addr; |
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len += sizeof(key.ipv4_addr); |
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break; |
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case AF_INET6: |
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key.hdr.port = sin6->sin6_port; |
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key.ipv6_addr = sin6->sin6_addr; |
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len += sizeof(key.ipv6_addr); |
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break; |
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default: |
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printk(KERN_WARNING "NFS: Unknown network family '%d'\n", |
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clp->cl_addr.ss_family); |
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clp->fscache = NULL; |
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return; |
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} |
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/* create a cache index for looking up filehandles */ |
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clp->fscache = fscache_acquire_cookie(nfs_fscache_netfs.primary_index, |
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&nfs_fscache_server_index_def, |
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&key, len, |
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NULL, 0, |
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clp, 0, true); |
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dfprintk(FSCACHE, "NFS: get client cookie (0x%p/0x%p)\n", |
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clp, clp->fscache); |
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} |
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|
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/* |
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* Dispose of a per-client cookie |
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*/ |
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void nfs_fscache_release_client_cookie(struct nfs_client *clp) |
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{ |
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dfprintk(FSCACHE, "NFS: releasing client cookie (0x%p/0x%p)\n", |
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clp, clp->fscache); |
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fscache_relinquish_cookie(clp->fscache, NULL, false); |
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clp->fscache = NULL; |
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} |
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/* |
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* Get the cache cookie for an NFS superblock. We have to handle |
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* uniquification here because the cache doesn't do it for us. |
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* |
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* The default uniquifier is just an empty string, but it may be overridden |
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* either by the 'fsc=xxx' option to mount, or by inheriting it from the parent |
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* superblock across an automount point of some nature. |
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*/ |
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void nfs_fscache_get_super_cookie(struct super_block *sb, const char *uniq, int ulen) |
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{ |
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struct nfs_fscache_key *key, *xkey; |
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struct nfs_server *nfss = NFS_SB(sb); |
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struct rb_node **p, *parent; |
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int diff; |
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nfss->fscache_key = NULL; |
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nfss->fscache = NULL; |
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if (!uniq) { |
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uniq = ""; |
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ulen = 1; |
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} |
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key = kzalloc(sizeof(*key) + ulen, GFP_KERNEL); |
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if (!key) |
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return; |
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key->nfs_client = nfss->nfs_client; |
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key->key.super.s_flags = sb->s_flags & NFS_SB_MASK; |
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key->key.nfs_server.flags = nfss->flags; |
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key->key.nfs_server.rsize = nfss->rsize; |
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key->key.nfs_server.wsize = nfss->wsize; |
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key->key.nfs_server.acregmin = nfss->acregmin; |
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key->key.nfs_server.acregmax = nfss->acregmax; |
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key->key.nfs_server.acdirmin = nfss->acdirmin; |
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key->key.nfs_server.acdirmax = nfss->acdirmax; |
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key->key.nfs_server.fsid = nfss->fsid; |
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key->key.rpc_auth.au_flavor = nfss->client->cl_auth->au_flavor; |
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key->key.uniq_len = ulen; |
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memcpy(key->key.uniquifier, uniq, ulen); |
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spin_lock(&nfs_fscache_keys_lock); |
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p = &nfs_fscache_keys.rb_node; |
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parent = NULL; |
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while (*p) { |
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parent = *p; |
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xkey = rb_entry(parent, struct nfs_fscache_key, node); |
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if (key->nfs_client < xkey->nfs_client) |
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goto go_left; |
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if (key->nfs_client > xkey->nfs_client) |
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goto go_right; |
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diff = memcmp(&key->key, &xkey->key, sizeof(key->key)); |
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if (diff < 0) |
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goto go_left; |
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if (diff > 0) |
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goto go_right; |
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if (key->key.uniq_len == 0) |
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goto non_unique; |
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diff = memcmp(key->key.uniquifier, |
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xkey->key.uniquifier, |
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key->key.uniq_len); |
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if (diff < 0) |
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goto go_left; |
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if (diff > 0) |
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goto go_right; |
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goto non_unique; |
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go_left: |
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p = &(*p)->rb_left; |
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continue; |
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go_right: |
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p = &(*p)->rb_right; |
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} |
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rb_link_node(&key->node, parent, p); |
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rb_insert_color(&key->node, &nfs_fscache_keys); |
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spin_unlock(&nfs_fscache_keys_lock); |
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nfss->fscache_key = key; |
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/* create a cache index for looking up filehandles */ |
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nfss->fscache = fscache_acquire_cookie(nfss->nfs_client->fscache, |
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&nfs_fscache_super_index_def, |
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&key->key, |
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sizeof(key->key) + ulen, |
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NULL, 0, |
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nfss, 0, true); |
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dfprintk(FSCACHE, "NFS: get superblock cookie (0x%p/0x%p)\n", |
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nfss, nfss->fscache); |
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return; |
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non_unique: |
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spin_unlock(&nfs_fscache_keys_lock); |
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kfree(key); |
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nfss->fscache_key = NULL; |
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nfss->fscache = NULL; |
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printk(KERN_WARNING "NFS:" |
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" Cache request denied due to non-unique superblock keys\n"); |
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} |
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/* |
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* release a per-superblock cookie |
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*/ |
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void nfs_fscache_release_super_cookie(struct super_block *sb) |
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{ |
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struct nfs_server *nfss = NFS_SB(sb); |
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dfprintk(FSCACHE, "NFS: releasing superblock cookie (0x%p/0x%p)\n", |
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nfss, nfss->fscache); |
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fscache_relinquish_cookie(nfss->fscache, NULL, false); |
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nfss->fscache = NULL; |
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if (nfss->fscache_key) { |
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spin_lock(&nfs_fscache_keys_lock); |
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rb_erase(&nfss->fscache_key->node, &nfs_fscache_keys); |
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spin_unlock(&nfs_fscache_keys_lock); |
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kfree(nfss->fscache_key); |
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nfss->fscache_key = NULL; |
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} |
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} |
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static void nfs_fscache_update_auxdata(struct nfs_fscache_inode_auxdata *auxdata, |
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struct nfs_inode *nfsi) |
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{ |
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memset(auxdata, 0, sizeof(*auxdata)); |
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auxdata->mtime_sec = nfsi->vfs_inode.i_mtime.tv_sec; |
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auxdata->mtime_nsec = nfsi->vfs_inode.i_mtime.tv_nsec; |
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auxdata->ctime_sec = nfsi->vfs_inode.i_ctime.tv_sec; |
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auxdata->ctime_nsec = nfsi->vfs_inode.i_ctime.tv_nsec; |
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if (NFS_SERVER(&nfsi->vfs_inode)->nfs_client->rpc_ops->version == 4) |
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auxdata->change_attr = inode_peek_iversion_raw(&nfsi->vfs_inode); |
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} |
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/* |
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* Initialise the per-inode cache cookie pointer for an NFS inode. |
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*/ |
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void nfs_fscache_init_inode(struct inode *inode) |
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{ |
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struct nfs_fscache_inode_auxdata auxdata; |
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struct nfs_server *nfss = NFS_SERVER(inode); |
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struct nfs_inode *nfsi = NFS_I(inode); |
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nfsi->fscache = NULL; |
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if (!(nfss->fscache && S_ISREG(inode->i_mode))) |
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return; |
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nfs_fscache_update_auxdata(&auxdata, nfsi); |
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nfsi->fscache = fscache_acquire_cookie(NFS_SB(inode->i_sb)->fscache, |
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&nfs_fscache_inode_object_def, |
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nfsi->fh.data, nfsi->fh.size, |
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&auxdata, sizeof(auxdata), |
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nfsi, nfsi->vfs_inode.i_size, false); |
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} |
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/* |
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* Release a per-inode cookie. |
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*/ |
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void nfs_fscache_clear_inode(struct inode *inode) |
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{ |
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struct nfs_fscache_inode_auxdata auxdata; |
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struct nfs_inode *nfsi = NFS_I(inode); |
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struct fscache_cookie *cookie = nfs_i_fscache(inode); |
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dfprintk(FSCACHE, "NFS: clear cookie (0x%p/0x%p)\n", nfsi, cookie); |
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nfs_fscache_update_auxdata(&auxdata, nfsi); |
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fscache_relinquish_cookie(cookie, &auxdata, false); |
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nfsi->fscache = NULL; |
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} |
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static bool nfs_fscache_can_enable(void *data) |
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{ |
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struct inode *inode = data; |
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return !inode_is_open_for_write(inode); |
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} |
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/* |
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* Enable or disable caching for a file that is being opened as appropriate. |
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* The cookie is allocated when the inode is initialised, but is not enabled at |
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* that time. Enablement is deferred to file-open time to avoid stat() and |
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* access() thrashing the cache. |
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* |
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* For now, with NFS, only regular files that are open read-only will be able |
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* to use the cache. |
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* |
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* We enable the cache for an inode if we open it read-only and it isn't |
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* currently open for writing. We disable the cache if the inode is open |
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* write-only. |
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* |
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* The caller uses the file struct to pin i_writecount on the inode before |
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* calling us when a file is opened for writing, so we can make use of that. |
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* |
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* Note that this may be invoked multiple times in parallel by parallel |
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* nfs_open() functions. |
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*/ |
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void nfs_fscache_open_file(struct inode *inode, struct file *filp) |
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{ |
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struct nfs_fscache_inode_auxdata auxdata; |
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struct nfs_inode *nfsi = NFS_I(inode); |
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struct fscache_cookie *cookie = nfs_i_fscache(inode); |
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if (!fscache_cookie_valid(cookie)) |
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return; |
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nfs_fscache_update_auxdata(&auxdata, nfsi); |
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if (inode_is_open_for_write(inode)) { |
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dfprintk(FSCACHE, "NFS: nfsi 0x%p disabling cache\n", nfsi); |
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clear_bit(NFS_INO_FSCACHE, &nfsi->flags); |
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fscache_disable_cookie(cookie, &auxdata, true); |
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fscache_uncache_all_inode_pages(cookie, inode); |
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} else { |
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dfprintk(FSCACHE, "NFS: nfsi 0x%p enabling cache\n", nfsi); |
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fscache_enable_cookie(cookie, &auxdata, nfsi->vfs_inode.i_size, |
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nfs_fscache_can_enable, inode); |
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if (fscache_cookie_enabled(cookie)) |
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set_bit(NFS_INO_FSCACHE, &NFS_I(inode)->flags); |
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} |
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} |
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EXPORT_SYMBOL_GPL(nfs_fscache_open_file); |
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/* |
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* Release the caching state associated with a page, if the page isn't busy |
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* interacting with the cache. |
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* - Returns true (can release page) or false (page busy). |
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*/ |
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int nfs_fscache_release_page(struct page *page, gfp_t gfp) |
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{ |
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if (PageFsCache(page)) { |
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struct fscache_cookie *cookie = nfs_i_fscache(page->mapping->host); |
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BUG_ON(!cookie); |
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dfprintk(FSCACHE, "NFS: fscache releasepage (0x%p/0x%p/0x%p)\n", |
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cookie, page, NFS_I(page->mapping->host)); |
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if (!fscache_maybe_release_page(cookie, page, gfp)) |
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return 0; |
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nfs_inc_fscache_stats(page->mapping->host, |
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NFSIOS_FSCACHE_PAGES_UNCACHED); |
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} |
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return 1; |
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} |
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/* |
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* Release the caching state associated with a page if undergoing complete page |
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* invalidation. |
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*/ |
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void __nfs_fscache_invalidate_page(struct page *page, struct inode *inode) |
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{ |
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struct fscache_cookie *cookie = nfs_i_fscache(inode); |
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BUG_ON(!cookie); |
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dfprintk(FSCACHE, "NFS: fscache invalidatepage (0x%p/0x%p/0x%p)\n", |
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cookie, page, NFS_I(inode)); |
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fscache_wait_on_page_write(cookie, page); |
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BUG_ON(!PageLocked(page)); |
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fscache_uncache_page(cookie, page); |
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nfs_inc_fscache_stats(page->mapping->host, |
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NFSIOS_FSCACHE_PAGES_UNCACHED); |
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} |
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/* |
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* Handle completion of a page being read from the cache. |
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* - Called in process (keventd) context. |
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*/ |
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static void nfs_readpage_from_fscache_complete(struct page *page, |
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void *context, |
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int error) |
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{ |
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dfprintk(FSCACHE, |
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"NFS: readpage_from_fscache_complete (0x%p/0x%p/%d)\n", |
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page, context, error); |
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/* |
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* If the read completes with an error, mark the page with PG_checked, |
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* unlock the page, and let the VM reissue the readpage. |
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*/ |
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if (!error) |
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SetPageUptodate(page); |
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else |
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SetPageChecked(page); |
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unlock_page(page); |
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} |
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/* |
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* Retrieve a page from fscache |
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*/ |
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int __nfs_readpage_from_fscache(struct nfs_open_context *ctx, |
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struct inode *inode, struct page *page) |
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{ |
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int ret; |
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dfprintk(FSCACHE, |
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"NFS: readpage_from_fscache(fsc:%p/p:%p(i:%lx f:%lx)/0x%p)\n", |
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nfs_i_fscache(inode), page, page->index, page->flags, inode); |
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if (PageChecked(page)) { |
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ClearPageChecked(page); |
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return 1; |
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} |
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ret = fscache_read_or_alloc_page(nfs_i_fscache(inode), |
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page, |
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nfs_readpage_from_fscache_complete, |
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ctx, |
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GFP_KERNEL); |
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switch (ret) { |
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case 0: /* read BIO submitted (page in fscache) */ |
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dfprintk(FSCACHE, |
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"NFS: readpage_from_fscache: BIO submitted\n"); |
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nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK); |
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return ret; |
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case -ENOBUFS: /* inode not in cache */ |
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case -ENODATA: /* page not in cache */ |
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nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL); |
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dfprintk(FSCACHE, |
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"NFS: readpage_from_fscache %d\n", ret); |
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return 1; |
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default: |
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dfprintk(FSCACHE, "NFS: readpage_from_fscache %d\n", ret); |
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nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL); |
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} |
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return ret; |
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} |
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/* |
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* Retrieve a set of pages from fscache |
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*/ |
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int __nfs_readpages_from_fscache(struct nfs_open_context *ctx, |
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struct inode *inode, |
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struct address_space *mapping, |
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struct list_head *pages, |
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unsigned *nr_pages) |
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{ |
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unsigned npages = *nr_pages; |
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int ret; |
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dfprintk(FSCACHE, "NFS: nfs_getpages_from_fscache (0x%p/%u/0x%p)\n", |
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nfs_i_fscache(inode), npages, inode); |
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ret = fscache_read_or_alloc_pages(nfs_i_fscache(inode), |
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mapping, pages, nr_pages, |
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nfs_readpage_from_fscache_complete, |
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ctx, |
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mapping_gfp_mask(mapping)); |
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if (*nr_pages < npages) |
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nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_OK, |
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npages); |
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if (*nr_pages > 0) |
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nfs_add_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_READ_FAIL, |
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*nr_pages); |
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|
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switch (ret) { |
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case 0: /* read submitted to the cache for all pages */ |
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BUG_ON(!list_empty(pages)); |
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BUG_ON(*nr_pages != 0); |
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dfprintk(FSCACHE, |
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"NFS: nfs_getpages_from_fscache: submitted\n"); |
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return ret; |
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case -ENOBUFS: /* some pages aren't cached and can't be */ |
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case -ENODATA: /* some pages aren't cached */ |
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dfprintk(FSCACHE, |
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"NFS: nfs_getpages_from_fscache: no page: %d\n", ret); |
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return 1; |
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|
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default: |
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dfprintk(FSCACHE, |
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"NFS: nfs_getpages_from_fscache: ret %d\n", ret); |
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} |
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return ret; |
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} |
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|
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/* |
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* Store a newly fetched page in fscache |
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* - PG_fscache must be set on the page |
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*/ |
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void __nfs_readpage_to_fscache(struct inode *inode, struct page *page, int sync) |
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{ |
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int ret; |
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|
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dfprintk(FSCACHE, |
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"NFS: readpage_to_fscache(fsc:%p/p:%p(i:%lx f:%lx)/%d)\n", |
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nfs_i_fscache(inode), page, page->index, page->flags, sync); |
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ret = fscache_write_page(nfs_i_fscache(inode), page, |
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inode->i_size, GFP_KERNEL); |
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dfprintk(FSCACHE, |
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"NFS: readpage_to_fscache: p:%p(i:%lu f:%lx) ret %d\n", |
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page, page->index, page->flags, ret); |
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|
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if (ret != 0) { |
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fscache_uncache_page(nfs_i_fscache(inode), page); |
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nfs_inc_fscache_stats(inode, |
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NFSIOS_FSCACHE_PAGES_WRITTEN_FAIL); |
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nfs_inc_fscache_stats(inode, NFSIOS_FSCACHE_PAGES_UNCACHED); |
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} else { |
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nfs_inc_fscache_stats(inode, |
|
NFSIOS_FSCACHE_PAGES_WRITTEN_OK); |
|
} |
|
}
|
|
|