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-rw-r--r--fs/cifs/cache.c331
1 files changed, 331 insertions, 0 deletions
diff --git a/fs/cifs/cache.c b/fs/cifs/cache.c
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+++ b/fs/cifs/cache.c
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+/*
+ * fs/cifs/cache.c - CIFS filesystem cache index structure definitions
+ *
+ * Copyright (c) 2010 Novell, Inc.
+ * Authors(s): Suresh Jayaraman (sjayaraman@suse.de>
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
+ * the GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include "fscache.h"
+#include "cifs_debug.h"
+
+/*
+ * CIFS filesystem definition for FS-Cache
+ */
+struct fscache_netfs cifs_fscache_netfs = {
+ .name = "cifs",
+ .version = 0,
+};
+
+/*
+ * Register CIFS for caching with FS-Cache
+ */
+int cifs_fscache_register(void)
+{
+ return fscache_register_netfs(&cifs_fscache_netfs);
+}
+
+/*
+ * Unregister CIFS for caching
+ */
+void cifs_fscache_unregister(void)
+{
+ fscache_unregister_netfs(&cifs_fscache_netfs);
+}
+
+/*
+ * Key layout of CIFS server cache index object
+ */
+struct cifs_server_key {
+ uint16_t family; /* address family */
+ uint16_t port; /* IP port */
+ union {
+ struct in_addr ipv4_addr;
+ struct in6_addr ipv6_addr;
+ } addr[0];
+};
+
+/*
+ * Server object keyed by {IPaddress,port,family} tuple
+ */
+static uint16_t cifs_server_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t maxbuf)
+{
+ const struct TCP_Server_Info *server = cookie_netfs_data;
+ const struct sockaddr *sa = (struct sockaddr *) &server->addr.sockAddr;
+ struct cifs_server_key *key = buffer;
+ uint16_t key_len = sizeof(struct cifs_server_key);
+
+ memset(key, 0, key_len);
+
+ /*
+ * Should not be a problem as sin_family/sin6_family overlays
+ * sa_family field
+ */
+ switch (sa->sa_family) {
+ case AF_INET:
+ key->family = server->addr.sockAddr.sin_family;
+ key->port = server->addr.sockAddr.sin_port;
+ key->addr[0].ipv4_addr = server->addr.sockAddr.sin_addr;
+ key_len += sizeof(key->addr[0].ipv4_addr);
+ break;
+
+ case AF_INET6:
+ key->family = server->addr.sockAddr6.sin6_family;
+ key->port = server->addr.sockAddr6.sin6_port;
+ key->addr[0].ipv6_addr = server->addr.sockAddr6.sin6_addr;
+ key_len += sizeof(key->addr[0].ipv6_addr);
+ break;
+
+ default:
+ cERROR(1, "CIFS: Unknown network family '%d'", sa->sa_family);
+ key_len = 0;
+ break;
+ }
+
+ return key_len;
+}
+
+/*
+ * Server object for FS-Cache
+ */
+const struct fscache_cookie_def cifs_fscache_server_index_def = {
+ .name = "CIFS.server",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+ .get_key = cifs_server_get_key,
+};
+
+/*
+ * Auxiliary data attached to CIFS superblock within the cache
+ */
+struct cifs_fscache_super_auxdata {
+ u64 resource_id; /* unique server resource id */
+};
+
+static char *extract_sharename(const char *treename)
+{
+ const char *src;
+ char *delim, *dst;
+ int len;
+
+ /* skip double chars at the beginning */
+ src = treename + 2;
+
+ /* share name is always preceded by '\\' now */
+ delim = strchr(src, '\\');
+ if (!delim)
+ return ERR_PTR(-EINVAL);
+ delim++;
+ len = strlen(delim);
+
+ /* caller has to free the memory */
+ dst = kstrndup(delim, len, GFP_KERNEL);
+ if (!dst)
+ return ERR_PTR(-ENOMEM);
+
+ return dst;
+}
+
+/*
+ * Superblock object currently keyed by share name
+ */
+static uint16_t cifs_super_get_key(const void *cookie_netfs_data, void *buffer,
+ uint16_t maxbuf)
+{
+ const struct cifsTconInfo *tcon = cookie_netfs_data;
+ char *sharename;
+ uint16_t len;
+
+ sharename = extract_sharename(tcon->treeName);
+ if (IS_ERR(sharename)) {
+ cFYI(1, "CIFS: couldn't extract sharename\n");
+ sharename = NULL;
+ return 0;
+ }
+
+ len = strlen(sharename);
+ if (len > maxbuf)
+ return 0;
+
+ memcpy(buffer, sharename, len);
+
+ kfree(sharename);
+
+ return len;
+}
+
+static uint16_t
+cifs_fscache_super_get_aux(const void *cookie_netfs_data, void *buffer,
+ uint16_t maxbuf)
+{
+ struct cifs_fscache_super_auxdata auxdata;
+ const struct cifsTconInfo *tcon = cookie_netfs_data;
+
+ memset(&auxdata, 0, sizeof(auxdata));
+ auxdata.resource_id = tcon->resource_id;
+
+ if (maxbuf > sizeof(auxdata))
+ maxbuf = sizeof(auxdata);
+
+ memcpy(buffer, &auxdata, maxbuf);
+
+ return maxbuf;
+}
+
+static enum
+fscache_checkaux cifs_fscache_super_check_aux(void *cookie_netfs_data,
+ const void *data,
+ uint16_t datalen)
+{
+ struct cifs_fscache_super_auxdata auxdata;
+ const struct cifsTconInfo *tcon = cookie_netfs_data;
+
+ if (datalen != sizeof(auxdata))
+ return FSCACHE_CHECKAUX_OBSOLETE;
+
+ memset(&auxdata, 0, sizeof(auxdata));
+ auxdata.resource_id = tcon->resource_id;
+
+ if (memcmp(data, &auxdata, datalen) != 0)
+ return FSCACHE_CHECKAUX_OBSOLETE;
+
+ return FSCACHE_CHECKAUX_OKAY;
+}
+
+/*
+ * Superblock object for FS-Cache
+ */
+const struct fscache_cookie_def cifs_fscache_super_index_def = {
+ .name = "CIFS.super",
+ .type = FSCACHE_COOKIE_TYPE_INDEX,
+ .get_key = cifs_super_get_key,
+ .get_aux = cifs_fscache_super_get_aux,
+ .check_aux = cifs_fscache_super_check_aux,
+};
+
+/*
+ * Auxiliary data attached to CIFS inode within the cache
+ */
+struct cifs_fscache_inode_auxdata {
+ struct timespec last_write_time;
+ struct timespec last_change_time;
+ u64 eof;
+};
+
+static uint16_t cifs_fscache_inode_get_key(const void *cookie_netfs_data,
+ void *buffer, uint16_t maxbuf)
+{
+ const struct cifsInodeInfo *cifsi = cookie_netfs_data;
+ uint16_t keylen;
+
+ /* use the UniqueId as the key */
+ keylen = sizeof(cifsi->uniqueid);
+ if (keylen > maxbuf)
+ keylen = 0;
+ else
+ memcpy(buffer, &cifsi->uniqueid, keylen);
+
+ return keylen;
+}
+
+static void
+cifs_fscache_inode_get_attr(const void *cookie_netfs_data, uint64_t *size)
+{
+ const struct cifsInodeInfo *cifsi = cookie_netfs_data;
+
+ *size = cifsi->vfs_inode.i_size;
+}
+
+static uint16_t
+cifs_fscache_inode_get_aux(const void *cookie_netfs_data, void *buffer,
+ uint16_t maxbuf)
+{
+ struct cifs_fscache_inode_auxdata auxdata;
+ const struct cifsInodeInfo *cifsi = cookie_netfs_data;
+
+ memset(&auxdata, 0, sizeof(auxdata));
+ auxdata.eof = cifsi->server_eof;
+ auxdata.last_write_time = cifsi->vfs_inode.i_mtime;
+ auxdata.last_change_time = cifsi->vfs_inode.i_ctime;
+
+ if (maxbuf > sizeof(auxdata))
+ maxbuf = sizeof(auxdata);
+
+ memcpy(buffer, &auxdata, maxbuf);
+
+ return maxbuf;
+}
+
+static enum
+fscache_checkaux cifs_fscache_inode_check_aux(void *cookie_netfs_data,
+ const void *data,
+ uint16_t datalen)
+{
+ struct cifs_fscache_inode_auxdata auxdata;
+ struct cifsInodeInfo *cifsi = cookie_netfs_data;
+
+ if (datalen != sizeof(auxdata))
+ return FSCACHE_CHECKAUX_OBSOLETE;
+
+ memset(&auxdata, 0, sizeof(auxdata));
+ auxdata.eof = cifsi->server_eof;
+ auxdata.last_write_time = cifsi->vfs_inode.i_mtime;
+ auxdata.last_change_time = cifsi->vfs_inode.i_ctime;
+
+ if (memcmp(data, &auxdata, datalen) != 0)
+ return FSCACHE_CHECKAUX_OBSOLETE;
+
+ return FSCACHE_CHECKAUX_OKAY;
+}
+
+static void cifs_fscache_inode_now_uncached(void *cookie_netfs_data)
+{
+ struct cifsInodeInfo *cifsi = cookie_netfs_data;
+ struct pagevec pvec;
+ pgoff_t first;
+ int loop, nr_pages;
+
+ pagevec_init(&pvec, 0);
+ first = 0;
+
+ cFYI(1, "cifs inode 0x%p now uncached", cifsi);
+
+ for (;;) {
+ nr_pages = pagevec_lookup(&pvec,
+ cifsi->vfs_inode.i_mapping, first,
+ PAGEVEC_SIZE - pagevec_count(&pvec));
+ if (!nr_pages)
+ break;
+
+ for (loop = 0; loop < nr_pages; loop++)
+ ClearPageFsCache(pvec.pages[loop]);
+
+ first = pvec.pages[nr_pages - 1]->index + 1;
+
+ pvec.nr = nr_pages;
+ pagevec_release(&pvec);
+ cond_resched();
+ }
+}
+
+const struct fscache_cookie_def cifs_fscache_inode_object_def = {
+ .name = "CIFS.uniqueid",
+ .type = FSCACHE_COOKIE_TYPE_DATAFILE,
+ .get_key = cifs_fscache_inode_get_key,
+ .get_attr = cifs_fscache_inode_get_attr,
+ .get_aux = cifs_fscache_inode_get_aux,
+ .check_aux = cifs_fscache_inode_check_aux,
+ .now_uncached = cifs_fscache_inode_now_uncached,
+};