smb: client: set ATTR_TEMPORARY with O_TMPFILE | O_EXCL

Set ATTR_TEMPORARY attribute on temporary delete-on-close files when
O_EXCL is specified in conjunction with O_TMPFILE to let some servers
cache as much data as possible and possibly never persist them into
storage, thereby improving performance.

Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: pcacjr

fs/smb/client/dir.c

@@ -1014,28 +1014,21 @@ static int cifs_ci_compare(const struct dentry *dentry,
 	return 0;
 }
 
-static int set_hidden_attr(const unsigned int xid,
-			   struct TCP_Server_Info *server,
-			   struct file *file)
+static int set_tmpfile_attr(const unsigned int xid, unsigned int oflags,
+			    struct inode *inode, const char *full_path,
+			    struct TCP_Server_Info *server)
 {
-	struct dentry *dentry = file->f_path.dentry;
-	struct cifsInodeInfo *cinode = CIFS_I(d_inode(dentry));
-	FILE_BASIC_INFO fi = {
-		.Attributes = cpu_to_le32(cinode->cifsAttrs |
-					  ATTR_HIDDEN),
-	};
-	void *page = alloc_dentry_path();
-	const char *full_path;
-	int rc;
+	struct cifsInodeInfo *cinode = CIFS_I(inode);
+	FILE_BASIC_INFO fi;
 
-	full_path = build_path_from_dentry(dentry, page);
-	if (IS_ERR(full_path))
-		rc = PTR_ERR(full_path);
-	else
-		rc =  server->ops->set_file_info(d_inode(dentry),
-						 full_path, &fi, xid);
-	free_dentry_path(page);
-	return rc;
+	cinode->cifsAttrs |= ATTR_HIDDEN;
+	if (oflags & O_EXCL)
+		cinode->cifsAttrs |= ATTR_TEMPORARY;
+
+	fi = (FILE_BASIC_INFO) {
+		.Attributes = cpu_to_le32(cinode->cifsAttrs),
+	};
+	return server->ops->set_file_info(inode, full_path, &fi, xid);
 }
 
 /*
@@ -1049,6 +1042,8 @@ int cifs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 {
 	struct dentry *dentry = file->f_path.dentry;
 	struct cifs_sb_info *cifs_sb = CIFS_SB(dir);
+	char *path __free(kfree) = NULL, *name;
+	unsigned int oflags = file->f_flags;
 	size_t size = CIFS_TMPNAME_LEN + 1;
 	int retries = 0, max_retries = 16;
 	struct TCP_Server_Info *server;
@@ -1059,7 +1054,6 @@ int cifs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 	struct cifs_tcon *tcon;
 	unsigned int sbflags;
 	struct inode *inode;
-	char *path, *name;
 	unsigned int xid;
 	__u32 oplock;
 	int rc;
@@ -1089,6 +1083,7 @@ int cifs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 	if (IS_ERR(path)) {
 		cifs_del_pending_open(&open);
 		rc = PTR_ERR(path);
+		path = NULL;
 		goto out;
 	}
 
@@ -1098,9 +1093,8 @@ int cifs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 			  CIFS_TMPNAME_PREFIX "%0*x",
 			  CIFS_TMPNAME_COUNTER_LEN,
 			  atomic_inc_return(&cifs_tmpcounter));
-		rc = __cifs_do_create(dir, dentry, path, xid, tlink,
-				      file->f_flags, mode, &oplock,
-				      &fid, NULL, &inode);
+		rc = __cifs_do_create(dir, dentry, path, xid, tlink, oflags,
+				      mode, &oplock, &fid, NULL, &inode);
 		if (!rc) {
 			set_nlink(inode, 0);
 			mark_inode_dirty(inode);
@@ -1110,7 +1104,6 @@ int cifs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 		}
 	} while (unlikely(rc == -EEXIST) && ++retries < max_retries);
 
-	kfree(path);
 	if (rc) {
 		cifs_del_pending_open(&open);
 		goto out;
@@ -1134,7 +1127,7 @@ int cifs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
 		goto err_open;
 	}
 
-	rc = set_hidden_attr(xid, server, file);
+	rc = set_tmpfile_attr(xid, oflags, inode, path, server);
 	if (rc)
 		goto out;
 

fs/smb/client/smb2inode.c

@@ -1237,6 +1237,20 @@ int smb2_rename_path(const unsigned int xid,
 	return rc;
 }
 
+static int clear_tmpfile_attr(const unsigned int xid, struct cifs_tcon *tcon,
+			      struct inode *inode, const char *full_path)
+{
+	struct TCP_Server_Info *server = cifs_pick_channel(tcon->ses);
+	struct cifsInodeInfo *cinode = CIFS_I(inode);
+	FILE_BASIC_INFO fi;
+
+	cinode->cifsAttrs &= ~(ATTR_TEMPORARY | ATTR_HIDDEN);
+	fi = (FILE_BASIC_INFO) {
+		.Attributes = cpu_to_le32(cinode->cifsAttrs),
+	};
+	return server->ops->set_file_info(inode, full_path, &fi, xid);
+}
+
 int smb2_create_hardlink(const unsigned int xid,
 			 struct cifs_tcon *tcon,
 			 struct dentry *source_dentry,
@@ -1246,24 +1260,14 @@ int smb2_create_hardlink(const unsigned int xid,
 	struct inode *inode = source_dentry ? d_inode(source_dentry) : NULL;
 	__u32 co = file_create_options(source_dentry);
 	struct cifsFileInfo *cfile;
+	int rc;
 
-	if (inode) {
-		struct cifsInodeInfo *cinode = CIFS_I(inode);
-		FILE_BASIC_INFO fi;
-		__le32 attrs;
-		int rc;
-
-		if (!test_bit(CIFS_INO_TMPFILE, &CIFS_I(inode)->flags))
-			goto out;
-
-		attrs = cpu_to_le32(cinode->cifsAttrs & ~ATTR_HIDDEN);
-		fi = (FILE_BASIC_INFO){ .Attributes = attrs, };
-		rc = smb2_set_file_info(inode, from_name, &fi, xid);
+	if (inode && test_bit(CIFS_INO_TMPFILE, &CIFS_I(inode)->flags)) {
+		rc = clear_tmpfile_attr(xid, tcon, inode, from_name);
 		if (rc)
 			return rc;
 	}
 
-out:
 	cifs_get_writable_path(tcon, from_name, inode,
 			       FIND_WITH_DELETE, &cfile);
 	return smb2_set_path_attr(xid, tcon, from_name, to_name,