1 files changed, 331 insertions, 0 deletions

diff --git a/fs/cifs/cache.c b/fs/cifs/cache.c
new file mode 100644
index 000000000000..224d7bbd1fcc
--- /dev/null
+++ b/fs/cifs/cache.c
@@ -0,0 +1,331 @@
+/*
+ *   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,
+};