From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762275AbZLKEuh (ORCPT ); Thu, 10 Dec 2009 23:50:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760816AbZLKEuU (ORCPT ); Thu, 10 Dec 2009 23:50:20 -0500 Received: from kroah.org ([198.145.64.141]:36928 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760794AbZLKEgP (ORCPT ); Thu, 10 Dec 2009 23:36:15 -0500 X-Mailbox-Line: From linux@linux.site Thu Dec 10 20:27:59 2009 Message-Id: <20091211042759.257547227@linux.site> User-Agent: quilt/0.47-14.9 Date: Thu, 10 Dec 2009 20:25:26 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Curt Wohlgemuth , "Theodore Tso" , Greg Kroah-Hartman Subject: [48/90] ext4: Handle nested ext4_journal_start/stop calls without a journal References: <20091211042438.970725457@linux.site> Content-Disposition: inline; filename=0048-ext4-Handle-nested-ext4_journal_start-stop-calls-wit.patch In-Reply-To: <20091211043502.GA17916@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ (cherry picked from commit d3d1faf6a74496ea4435fd057c6a2cad49f3e523) This patch fixes a problem with handling nested calls to ext4_journal_start/ext4_journal_stop, when there is no journal present. Signed-off-by: Curt Wohlgemuth Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/ext4_jbd2.h | 6 ++++-- fs/ext4/namei.c | 3 ++- fs/ext4/super.c | 42 ++++++++++++++++++++++++++++++++---------- 3 files changed, 38 insertions(+), 13 deletions(-) --- a/fs/ext4/ext4_jbd2.h +++ b/fs/ext4/ext4_jbd2.h @@ -161,11 +161,13 @@ int __ext4_handle_dirty_metadata(const c handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks); int __ext4_journal_stop(const char *where, handle_t *handle); -#define EXT4_NOJOURNAL_HANDLE ((handle_t *) 0x1) +#define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096) +/* Note: Do not use this for NULL handles. This is only to determine if + * a properly allocated handle is using a journal or not. */ static inline int ext4_handle_valid(handle_t *handle) { - if (handle == EXT4_NOJOURNAL_HANDLE) + if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT) return 0; return 1; } --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -2068,7 +2068,8 @@ int ext4_orphan_del(handle_t *handle, st struct ext4_iloc iloc; int err = 0; - if (!ext4_handle_valid(handle)) + /* ext4_handle_valid() assumes a valid handle_t pointer */ + if (handle && !ext4_handle_valid(handle)) return 0; mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock); --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -189,6 +189,36 @@ void ext4_itable_unused_set(struct super bg->bg_itable_unused_hi = cpu_to_le16(count >> 16); } + +/* Just increment the non-pointer handle value */ +static handle_t *ext4_get_nojournal(void) +{ + handle_t *handle = current->journal_info; + unsigned long ref_cnt = (unsigned long)handle; + + BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT); + + ref_cnt++; + handle = (handle_t *)ref_cnt; + + current->journal_info = handle; + return handle; +} + + +/* Decrement the non-pointer handle value */ +static void ext4_put_nojournal(handle_t *handle) +{ + unsigned long ref_cnt = (unsigned long)handle; + + BUG_ON(ref_cnt == 0); + + ref_cnt--; + handle = (handle_t *)ref_cnt; + + current->journal_info = handle; +} + /* * Wrappers for jbd2_journal_start/end. * @@ -215,11 +245,7 @@ handle_t *ext4_journal_start_sb(struct s } return jbd2_journal_start(journal, nblocks); } - /* - * We're not journaling, return the appropriate indication. - */ - current->journal_info = EXT4_NOJOURNAL_HANDLE; - return current->journal_info; + return ext4_get_nojournal(); } /* @@ -235,11 +261,7 @@ int __ext4_journal_stop(const char *wher int rc; if (!ext4_handle_valid(handle)) { - /* - * Do this here since we don't call jbd2_journal_stop() in - * no-journal mode. - */ - current->journal_info = NULL; + ext4_put_nojournal(handle); return 0; } sb = handle->h_transaction->t_journal->j_private;