1 files changed, 236 insertions, 0 deletions

diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
new file mode 100644
index 00000000000..9f3f5c4be16
--- /dev/null
+++ b/fs/cifs/fscache.c
@@ -0,0 +1,236 @@
+/*
+ *   fs/cifs/fscache.c - CIFS filesystem cache interface
+ *
+ *   Copyright (c) 2010 Novell, Inc.
+ *   Author(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 "cifsglob.h"
+#include "cifs_debug.h"
+#include "cifs_fs_sb.h"
+
+void cifs_fscache_get_client_cookie(struct TCP_Server_Info *server)
+{
+        server->fscache =
+                fscache_acquire_cookie(cifs_fscache_netfs.primary_index,
+                                &cifs_fscache_server_index_def, server);
+        cFYI(1, "CIFS: get client cookie (0x%p/0x%p)", server,
+                                server->fscache);
+}
+
+void cifs_fscache_release_client_cookie(struct TCP_Server_Info *server)
+{
+        cFYI(1, "CIFS: release client cookie (0x%p/0x%p)", server,
+                                server->fscache);
+        fscache_relinquish_cookie(server->fscache, 0);
+        server->fscache = NULL;
+}
+
+void cifs_fscache_get_super_cookie(struct cifsTconInfo *tcon)
+{
+        struct TCP_Server_Info *server = tcon->ses->server;
+
+        tcon->fscache =
+                fscache_acquire_cookie(server->fscache,
+                                &cifs_fscache_super_index_def, tcon);
+        cFYI(1, "CIFS: get superblock cookie (0x%p/0x%p)",
+                                server->fscache, tcon->fscache);
+}
+
+void cifs_fscache_release_super_cookie(struct cifsTconInfo *tcon)
+{
+        cFYI(1, "CIFS: releasing superblock cookie (0x%p)", tcon->fscache);
+        fscache_relinquish_cookie(tcon->fscache, 0);
+        tcon->fscache = NULL;
+}
+
+static void cifs_fscache_enable_inode_cookie(struct inode *inode)
+{
+        struct cifsInodeInfo *cifsi = CIFS_I(inode);
+        struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+
+        if (cifsi->fscache)
+                return;
+
+        cifsi->fscache = fscache_acquire_cookie(cifs_sb->tcon->fscache,
+                                &cifs_fscache_inode_object_def,
+                                cifsi);
+        cFYI(1, "CIFS: got FH cookie (0x%p/0x%p)",
+                        cifs_sb->tcon->fscache, cifsi->fscache);
+}
+
+void cifs_fscache_release_inode_cookie(struct inode *inode)
+{
+        struct cifsInodeInfo *cifsi = CIFS_I(inode);
+
+        if (cifsi->fscache) {
+                cFYI(1, "CIFS releasing inode cookie (0x%p)",
+                                cifsi->fscache);
+                fscache_relinquish_cookie(cifsi->fscache, 0);
+                cifsi->fscache = NULL;
+        }
+}
+
+static void cifs_fscache_disable_inode_cookie(struct inode *inode)
+{
+        struct cifsInodeInfo *cifsi = CIFS_I(inode);
+
+        if (cifsi->fscache) {
+                cFYI(1, "CIFS disabling inode cookie (0x%p)",
+                                cifsi->fscache);
+                fscache_relinquish_cookie(cifsi->fscache, 1);
+                cifsi->fscache = NULL;
+        }
+}
+
+void cifs_fscache_set_inode_cookie(struct inode *inode, struct file *filp)
+{
+        if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
+                cifs_fscache_disable_inode_cookie(inode);
+        else {
+                cifs_fscache_enable_inode_cookie(inode);
+                cFYI(1, "CIFS: fscache inode cookie set");
+        }
+}
+
+void cifs_fscache_reset_inode_cookie(struct inode *inode)
+{
+        struct cifsInodeInfo *cifsi = CIFS_I(inode);
+        struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+        struct fscache_cookie *old = cifsi->fscache;
+
+        if (cifsi->fscache) {
+                /* retire the current fscache cache and get a new one */
+                fscache_relinquish_cookie(cifsi->fscache, 1);
+
+                cifsi->fscache = fscache_acquire_cookie(cifs_sb->tcon->fscache,
+                                        &cifs_fscache_inode_object_def,
+                                        cifsi);
+                cFYI(1, "CIFS: new cookie 0x%p oldcookie 0x%p",
+                                cifsi->fscache, old);
+        }
+}
+
+int cifs_fscache_release_page(struct page *page, gfp_t gfp)
+{
+        if (PageFsCache(page)) {
+                struct inode *inode = page->mapping->host;
+                struct cifsInodeInfo *cifsi = CIFS_I(inode);
+
+                cFYI(1, "CIFS: fscache release page (0x%p/0x%p)",
+                                page, cifsi->fscache);
+                if (!fscache_maybe_release_page(cifsi->fscache, page, gfp))
+                        return 0;
+        }
+
+        return 1;
+}
+
+static void cifs_readpage_from_fscache_complete(struct page *page, void *ctx,
+                                                int error)
+{
+        cFYI(1, "CFS: readpage_from_fscache_complete (0x%p/%d)",
+                        page, error);
+        if (!error)
+                SetPageUptodate(page);
+        unlock_page(page);
+}
+
+/*
+ * Retrieve a page from FS-Cache
+ */
+int __cifs_readpage_from_fscache(struct inode *inode, struct page *page)
+{
+        int ret;
+
+        cFYI(1, "CIFS: readpage_from_fscache(fsc:%p, p:%p, i:0x%p",
+                        CIFS_I(inode)->fscache, page, inode);
+        ret = fscache_read_or_alloc_page(CIFS_I(inode)->fscache, page,
+                                         cifs_readpage_from_fscache_complete,
+                                         NULL,
+                                         GFP_KERNEL);
+        switch (ret) {
+
+        case 0: /* page found in fscache, read submitted */
+                cFYI(1, "CIFS: readpage_from_fscache: submitted");
+                return ret;
+        case -ENOBUFS:  /* page won't be cached */
+        case -ENODATA:  /* page not in cache */
+                cFYI(1, "CIFS: readpage_from_fscache %d", ret);
+                return 1;
+
+        default:
+                cERROR(1, "unknown error ret = %d", ret);
+        }
+        return ret;
+}
+
+/*
+ * Retrieve a set of pages from FS-Cache
+ */
+int __cifs_readpages_from_fscache(struct inode *inode,
+                                struct address_space *mapping,
+                                struct list_head *pages,
+                                unsigned *nr_pages)
+{
+        int ret;
+
+        cFYI(1, "CIFS: __cifs_readpages_from_fscache (0x%p/%u/0x%p)",
+                        CIFS_I(inode)->fscache, *nr_pages, inode);
+        ret = fscache_read_or_alloc_pages(CIFS_I(inode)->fscache, mapping,
+                                          pages, nr_pages,
+                                          cifs_readpage_from_fscache_complete,
+                                          NULL,
+                                          mapping_gfp_mask(mapping));
+        switch (ret) {
+        case 0: /* read submitted to the cache for all pages */
+                cFYI(1, "CIFS: readpages_from_fscache: submitted");
+                return ret;
+
+        case -ENOBUFS:  /* some pages are not cached and can't be */
+        case -ENODATA:  /* some pages are not cached */
+                cFYI(1, "CIFS: readpages_from_fscache: no page");
+                return 1;
+
+        default:
+                cFYI(1, "unknown error ret = %d", ret);
+        }
+
+        return ret;
+}
+
+void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
+{
+        int ret;
+
+        cFYI(1, "CIFS: readpage_to_fscache(fsc: %p, p: %p, i: %p",
+                        CIFS_I(inode)->fscache, page, inode);
+        ret = fscache_write_page(CIFS_I(inode)->fscache, page, GFP_KERNEL);
+        if (ret != 0)
+                fscache_uncache_page(CIFS_I(inode)->fscache, page);
+}
+
+void __cifs_fscache_invalidate_page(struct page *page, struct inode *inode)
+{
+        struct cifsInodeInfo *cifsi = CIFS_I(inode);
+        struct fscache_cookie *cookie = cifsi->fscache;
+
+        cFYI(1, "CIFS: fscache invalidatepage (0x%p/0x%p)", page, cookie);
+        fscache_wait_on_page_write(cookie, page);
+        fscache_uncache_page(cookie, page);
+}
+