From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933407AbcBYRsU (ORCPT ); Thu, 25 Feb 2016 12:48:20 -0500 Received: from 78-80-28-91.tmcz.cz ([78.80.28.91]:43776 "EHLO leontynka.twibright.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S932381AbcBYRsS (ORCPT ); Thu, 25 Feb 2016 12:48:18 -0500 Date: Thu, 25 Feb 2016 18:17:38 +0100 (CET) From: Mikulas Patocka X-X-Sender: mikulas@leontynka To: Linus Torvalds cc: Al Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] hpfs: don't truncate the file when delete fails Message-ID: User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The delete opration can allocate additional space on the HPFS filesystem due to btree split. The HPFS driver checks in advance if there is available space, so that it won't corrupt the btree if we run out of space during splitting. If there is not enough available space, the HPFS driver attempted to truncate the file, but this results in a deadlock since the commit 7dd29d8d865efdb00c0542a5d2c87af8c52ea6c7 ("HPFS: Introduce a global mutex and lock it on every callback from VFS"). This patch removes the code that tries to truncate the file and -ENOSPC is returned instead. If the user hits -ENOSPC on delete, he should try to delete other files (that are stored in a leaf btree node), so that the delete operation will make some space for deleting the file stored in non-leaf btree node. Reported-by: Al Viro Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org # 2.6.39+ Index: linux-4.4.2/fs/hpfs/namei.c =================================================================== --- linux-4.4.2.orig/fs/hpfs/namei.c +++ linux-4.4.2/fs/hpfs/namei.c @@ -375,12 +375,11 @@ static int hpfs_unlink(struct inode *dir struct inode *inode = d_inode(dentry); dnode_secno dno; int r; - int rep = 0; int err; hpfs_lock(dir->i_sb); hpfs_adjust_length(name, &len); -again: + err = -ENOENT; de = map_dirent(dir, hpfs_i(dir)->i_dno, name, len, &dno, &qbh); if (!de) @@ -400,33 +399,9 @@ again: hpfs_error(dir->i_sb, "there was error when removing dirent"); err = -EFSERROR; break; - case 2: /* no space for deleting, try to truncate file */ - + case 2: /* no space for deleting */ err = -ENOSPC; - if (rep++) - break; - - dentry_unhash(dentry); - if (!d_unhashed(dentry)) { - hpfs_unlock(dir->i_sb); - return -ENOSPC; - } - if (generic_permission(inode, MAY_WRITE) || - !S_ISREG(inode->i_mode) || - get_write_access(inode)) { - d_rehash(dentry); - } else { - struct iattr newattrs; - /*pr_info("truncating file before delete.\n");*/ - newattrs.ia_size = 0; - newattrs.ia_valid = ATTR_SIZE | ATTR_CTIME; - err = notify_change(dentry, &newattrs, NULL); - put_write_access(inode); - if (!err) - goto again; - } - hpfs_unlock(dir->i_sb); - return -ENOSPC; + break; default: drop_nlink(inode); err = 0;