1 files changed, 20 insertions, 109 deletions

diff --git a/fs/smb/client/fscache.c b/fs/smb/client/fscache.c
index 340efce8f052..01424a5cdb99 100644
--- a/fs/smb/client/fscache.c
+++ b/fs/smb/client/fscache.c
@@ -43,12 +43,23 @@ int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
 	char *key;
 	int ret = -ENOMEM;
 
+	if (tcon->fscache_acquired)
+		return 0;
+
+	mutex_lock(&tcon->fscache_lock);
+	if (tcon->fscache_acquired) {
+		mutex_unlock(&tcon->fscache_lock);
+		return 0;
+	}
+	tcon->fscache_acquired = true;
+
 	tcon->fscache = NULL;
 	switch (sa->sa_family) {
 	case AF_INET:
 	case AF_INET6:
 		break;
 	default:
+		mutex_unlock(&tcon->fscache_lock);
 		cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
 		return -EINVAL;
 	}
@@ -57,6 +68,7 @@ int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
 
 	sharename = extract_sharename(tcon->tree_name);
 	if (IS_ERR(sharename)) {
+		mutex_unlock(&tcon->fscache_lock);
 		cifs_dbg(FYI, "%s: couldn't extract sharename\n", __func__);
 		return PTR_ERR(sharename);
 	}
@@ -82,6 +94,11 @@ int cifs_fscache_get_super_cookie(struct cifs_tcon *tcon)
 		}
 		pr_err("Cache volume key already in use (%s)\n", key);
 		vcookie = NULL;
+		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+				    netfs_trace_tcon_ref_see_fscache_collision);
+	} else {
+		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+				    netfs_trace_tcon_ref_see_fscache_okay);
 	}
 
 	tcon->fscache = vcookie;
@@ -90,6 +107,7 @@ out_2:
 	kfree(key);
 out:
 	kfree(sharename);
+	mutex_unlock(&tcon->fscache_lock);
 	return ret;
 }
 
@@ -102,6 +120,8 @@ void cifs_fscache_release_super_cookie(struct cifs_tcon *tcon)
 	cifs_fscache_fill_volume_coherency(tcon, &cd);
 	fscache_relinquish_volume(tcon->fscache, &cd, false);
 	tcon->fscache = NULL;
+	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
+			    netfs_trace_tcon_ref_see_fscache_relinq);
 }
 
 void cifs_fscache_get_inode_cookie(struct inode *inode)
@@ -150,112 +170,3 @@ void cifs_fscache_release_inode_cookie(struct inode *inode)
 		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;
-	int ret;
-
-	memset(&cres, 0, sizeof(cres));
-	bvec_set_page(&bvec, page, PAGE_SIZE, 0);
-	iov_iter_bvec(&iter, ITER_DEST, &bvec, 1, 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_pages(struct inode *inode, loff_t start, size_t len,
-					bool no_space_allocated_yet)
-{
-	struct netfs_cache_resources cres;
-	struct fscache_cookie *cookie = cifs_inode_cookie(inode);
-	struct iov_iter iter;
-	int ret;
-
-	memset(&cres, 0, sizeof(cres));
-	iov_iter_xarray(&iter, ITER_SOURCE, &inode->i_mapping->i_pages, start, len);
-
-	ret = fscache_begin_write_operation(&cres, cookie);
-	if (ret < 0)
-		return ret;
-
-	ret = cres.ops->prepare_write(&cres, &start, &len, len, i_size_read(inode),
-				      no_space_allocated_yet);
-	if (ret == 0)
-		ret = fscache_write(&cres, start, &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_readahead_to_fscache(struct inode *inode, loff_t pos, size_t len)
-{
-	cifs_dbg(FYI, "%s: (fsc: %p, p: %llx, l: %zx, i: %p)\n",
-		 __func__, cifs_inode_cookie(inode), pos, len, inode);
-
-	fscache_fallback_write_pages(inode, pos, len, 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;
-}