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-rw-r--r--fs/smb/client/fscache.c255
1 files changed, 255 insertions, 0 deletions
diff --git a/fs/smb/client/fscache.c b/fs/smb/client/fscache.c
new file mode 100644
index 000000000..f64bad513
--- /dev/null
+++ b/fs/smb/client/fscache.c
@@ -0,0 +1,255 @@
+// SPDX-License-Identifier: LGPL-2.1
+/*
+ * CIFS filesystem cache interface
+ *
+ * Copyright (c) 2010 Novell, Inc.
+ * Author(s): Suresh Jayaraman <sjayaraman@suse.de>
+ *
+ */
+#include "fscache.h"
+#include "cifsglob.h"
+#include "cifs_debug.h"
+#include "cifs_fs_sb.h"
+#include "cifsproto.h"
+
+static void cifs_fscache_fill_volume_coherency(
+ struct cifs_tcon *tcon,
+ struct cifs_fscache_volume_coherency_data *cd)
+{
+ memset(cd, 0, sizeof(*cd));
+ cd->resource_id = cpu_to_le64(tcon->resource_id);
+ cd->vol_create_time = tcon->vol_create_time;
+ cd->vol_serial_number = cpu_to_le32(tcon->vol_serial_number);
+}
+
+int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
+{
+ struct cifs_fscache_volume_coherency_data cd;
+ struct TCP_Server_Info *server = tcon->ses->server;
+ struct fscache_volume *vcookie;
+ const struct sockaddr *sa = (struct sockaddr *)&server->dstaddr;
+ size_t slen, i;
+ char *sharename;
+ char *key;
+ int ret = -ENOMEM;
+
+ tcon->fscache = NULL;
+ switch (sa->sa_family) {
+ case AF_INET:
+ case AF_INET6:
+ break;
+ default:
+ cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
+ return -EINVAL;
+ }
+
+ memset(&key, 0, sizeof(key));
+
+ sharename = extract_sharename(tcon->tree_name);
+ if (IS_ERR(sharename)) {
+ cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__);
+ return PTR_ERR(sharename);
+ }
+
+ slen = strlen(sharename);
+ for (i = 0; i < slen; i++)
+ if (sharename[i] == '/')
+ sharename[i] = ';';
+
+ key = kasprintf(GFP_KERNEL, "cifs,%pISpc,%s", sa, sharename);
+ if (!key)
+ goto out;
+
+ cifs_fscache_fill_volume_coherency(tcon, &cd);
+ vcookie = fscache_acquire_volume(key,
+ NULL, /* preferred_cache */
+ &cd, sizeof(cd));
+ cifs_dbg(FYI, "%s: (%s/0x%p)\n", __func__, key, vcookie);
+ if (IS_ERR(vcookie)) {
+ if (vcookie != ERR_PTR(-EBUSY)) {
+ ret = PTR_ERR(vcookie);
+ goto out_2;
+ }
+ pr_err("Cache volume key already in use (%s)\n", key);
+ vcookie = NULL;
+ }
+
+ tcon->fscache = vcookie;
+ ret = 0;
+out_2:
+ kfree(key);
+out:
+ kfree(sharename);
+ return ret;
+}
+
+void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
+{
+ struct cifs_fscache_volume_coherency_data cd;
+
+ cifs_dbg(FYI, "%s: (0x%p)\n", __func__, tcon->fscache);
+
+ cifs_fscache_fill_volume_coherency(tcon, &cd);
+ fscache_relinquish_volume(tcon->fscache, &cd, false);
+ tcon->fscache = NULL;
+}
+
+void cifs_fscache_get_inode_cookie(struct inode *inode)
+{
+ struct cifs_fscache_inode_coherency_data cd;
+ 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);
+
+ cifs_fscache_fill_coherency(&cifsi->netfs.inode, &cd);
+
+ cifsi->netfs.cache =
+ fscache_acquire_cookie(tcon->fscache, 0,
+ &cifsi->uniqueid, sizeof(cifsi->uniqueid),
+ &cd, sizeof(cd),
+ i_size_read(&cifsi->netfs.inode));
+ if (cifsi->netfs.cache)
+ mapping_set_release_always(inode->i_mapping);
+}
+
+void cifs_fscache_unuse_inode_cookie(struct inode *inode, bool update)
+{
+ if (update) {
+ struct cifs_fscache_inode_coherency_data cd;
+ loff_t i_size = i_size_read(inode);
+
+ cifs_fscache_fill_coherency(inode, &cd);
+ fscache_unuse_cookie(cifs_inode_cookie(inode), &cd, &i_size);
+ } else {
+ fscache_unuse_cookie(cifs_inode_cookie(inode), NULL, NULL);
+ }
+}
+
+void cifs_fscache_release_inode_cookie(struct inode *inode)
+{
+ struct cifsInodeInfo *cifsi = CIFS_I(inode);
+ struct fscache_cookie *cookie = cifs_inode_cookie(inode);
+
+ if (cookie) {
+ cifs_dbg(FYI, "%s: (0x%p)\n", __func__, cookie);
+ fscache_relinquish_cookie(cookie, false);
+ cifsi->netfs.cache = NULL;
+ }
+}
+
+/*
+ * Fallback page reading interface.
+ */
+static int fscache_fallback_read_page(struct inode *inode, struct page *page)
+{
+ struct netfs_cache_resources cres;
+ struct fscache_cookie *cookie = cifs_inode_cookie(inode);
+ struct iov_iter iter;
+ struct bio_vec bvec[1];
+ int ret;
+
+ memset(&cres, 0, sizeof(cres));
+ bvec[0].bv_page = page;
+ bvec[0].bv_offset = 0;
+ bvec[0].bv_len = PAGE_SIZE;
+ iov_iter_bvec(&iter, ITER_DEST, bvec, ARRAY_SIZE(bvec), PAGE_SIZE);
+
+ ret = fscache_begin_read_operation(&cres, cookie);
+ if (ret < 0)
+ return ret;
+
+ ret = fscache_read(&cres, page_offset(page), &iter, NETFS_READ_HOLE_FAIL,
+ NULL, NULL);
+ fscache_end_operation(&cres);
+ return ret;
+}
+
+/*
+ * Fallback page writing interface.
+ */
+static int fscache_fallback_write_page(struct inode *inode, struct page *page,
+ bool no_space_allocated_yet)
+{
+ struct netfs_cache_resources cres;
+ struct fscache_cookie *cookie = cifs_inode_cookie(inode);
+ struct iov_iter iter;
+ struct bio_vec bvec[1];
+ loff_t start = page_offset(page);
+ size_t len = PAGE_SIZE;
+ int ret;
+
+ memset(&cres, 0, sizeof(cres));
+ bvec[0].bv_page = page;
+ bvec[0].bv_offset = 0;
+ bvec[0].bv_len = PAGE_SIZE;
+ iov_iter_bvec(&iter, ITER_SOURCE, bvec, ARRAY_SIZE(bvec), PAGE_SIZE);
+
+ ret = fscache_begin_write_operation(&cres, cookie);
+ if (ret < 0)
+ return ret;
+
+ ret = cres.ops->prepare_write(&cres, &start, &len, i_size_read(inode),
+ no_space_allocated_yet);
+ if (ret == 0)
+ ret = fscache_write(&cres, page_offset(page), &iter, NULL, NULL);
+ fscache_end_operation(&cres);
+ return ret;
+}
+
+/*
+ * 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_inode_cookie(inode), page, inode);
+
+ ret = fscache_fallback_read_page(inode, page);
+ if (ret < 0)
+ return ret;
+
+ /* Read completed synchronously */
+ SetPageUptodate(page);
+ return 0;
+}
+
+void __cifs_readpage_to_fscache(struct inode *inode, struct page *page)
+{
+ cifs_dbg(FYI, "%s: (fsc: %p, p: %p, i: %p)\n",
+ __func__, cifs_inode_cookie(inode), page, inode);
+
+ fscache_fallback_write_page(inode, page, true);
+}
+
+/*
+ * Query the cache occupancy.
+ */
+int __cifs_fscache_query_occupancy(struct inode *inode,
+ pgoff_t first, unsigned int nr_pages,
+ pgoff_t *_data_first,
+ unsigned int *_data_nr_pages)
+{
+ struct netfs_cache_resources cres;
+ struct fscache_cookie *cookie = cifs_inode_cookie(inode);
+ loff_t start, data_start;
+ size_t len, data_len;
+ int ret;
+
+ ret = fscache_begin_read_operation(&cres, cookie);
+ if (ret < 0)
+ return ret;
+
+ start = first * PAGE_SIZE;
+ len = nr_pages * PAGE_SIZE;
+ ret = cres.ops->query_occupancy(&cres, start, len, PAGE_SIZE,
+ &data_start, &data_len);
+ if (ret == 0) {
+ *_data_first = data_start / PAGE_SIZE;
+ *_data_nr_pages = len / PAGE_SIZE;
+ }
+
+ fscache_end_operation(&cres);
+ return ret;
+}