Initial import

1 files changed, 242 insertions, 0 deletions

diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
new file mode 100644
index 000000000..8d4b7bc8a
--- /dev/null
+++ b/fs/cifs/fscache.c
@@ -0,0 +1,242 @@
+/*
+ *   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, true);
+	cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
+		 __func__, server, server->fscache);
+}
+
+void cifs_fscache_release_client_cookie(struct TCP_Server_Info *server)
+{
+	cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
+		 __func__, server, server->fscache);
+	fscache_relinquish_cookie(server->fscache, 0);
+	server->fscache = NULL;
+}
+
+void cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
+{
+	struct TCP_Server_Info *server = tcon->ses->server;
+
+	tcon->fscache =
+		fscache_acquire_cookie(server->fscache,
+				&cifs_fscache_super_index_def, tcon, true);
+	cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
+		 __func__, server->fscache, tcon->fscache);
+}
+
+void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
+{
+	cifs_dbg(FYI, "%s: (0x%p)\n", __func__, 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);
+	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
+
+	if (cifsi->fscache)
+		return;
+
+	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE) {
+		cifsi->fscache = fscache_acquire_cookie(tcon->fscache,
+				&cifs_fscache_inode_object_def, cifsi, true);
+		cifs_dbg(FYI, "%s: got FH cookie (0x%p/0x%p)\n",
+			 __func__, tcon->fscache, cifsi->fscache);
+	}
+}
+
+void cifs_fscache_release_inode_cookie(struct inode *inode)
+{
+	struct cifsInodeInfo *cifsi = CIFS_I(inode);
+
+	if (cifsi->fscache) {
+		cifs_dbg(FYI, "%s: (0x%p)\n", __func__, 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) {
+		cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cifsi->fscache);
+		fscache_uncache_all_inode_pages(cifsi->fscache, inode);
+		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);
+}
+
+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_master_tcon(cifs_sb)->fscache,
+					&cifs_fscache_inode_object_def,
+					cifsi, true);
+		cifs_dbg(FYI, "%s: new cookie 0x%p oldcookie 0x%p\n",
+			 __func__, 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);
+
+		cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",
+			 __func__, 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)
+{
+	cifs_dbg(FYI, "%s: (0x%p/%d)\n", __func__, 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;
+
+	cifs_dbg(FYI, "%s: (fsc:%p, p:%p, i:0x%p\n",
+		 __func__, 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 */
+		cifs_dbg(FYI, "%s: submitted\n", __func__);
+		return ret;
+	case -ENOBUFS:	/* page won't be cached */
+	case -ENODATA:	/* page not in cache */
+		cifs_dbg(FYI, "%s: %d\n", __func__, ret);
+		return 1;
+
+	default:
+		cifs_dbg(VFS, "unknown error ret = %d\n", 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;
+
+	cifs_dbg(FYI, "%s: (0x%p/%u/0x%p)\n",
+		 __func__, 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 */
+		cifs_dbg(FYI, "%s: submitted\n", __func__);
+		return ret;
+
+	case -ENOBUFS:	/* some pages are not cached and can't be */
+	case -ENODATA:	/* some pages are not cached */
+		cifs_dbg(FYI, "%s: no page\n", __func__);
+		return 1;
+
+	default:
+		cifs_dbg(FYI, "unknown error ret = %d\n", ret);
+	}
+
+	return ret;
+}
+
+void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
+{
+	int ret;
+
+	cifs_dbg(FYI, "%s: (fsc: %p, p: %p, i: %p)\n",
+		 __func__, 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_readpages_cancel(struct inode *inode, struct list_head *pages)
+{
+	cifs_dbg(FYI, "%s: (fsc: %p, i: %p)\n",
+		 __func__, CIFS_I(inode)->fscache, inode);
+	fscache_readpages_cancel(CIFS_I(inode)->fscache, pages);
+}
+
+void __cifs_fscache_invalidate_page(struct page *page, struct inode *inode)
+{
+	struct cifsInodeInfo *cifsi = CIFS_I(inode);
+	struct fscache_cookie *cookie = cifsi->fscache;
+
+	cifs_dbg(FYI, "%s: (0x%p/0x%p)\n", __func__, page, cookie);
+	fscache_wait_on_page_write(cookie, page);
+	fscache_uncache_page(cookie, page);
+}
+