From patchwork Fri Jan 20 20:34:44 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Kara X-Patchwork-Id: 137100 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 8B56DB6F13 for ; Sat, 21 Jan 2012 07:38:08 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755877Ab2ATUfM (ORCPT ); Fri, 20 Jan 2012 15:35:12 -0500 Received: from cantor2.suse.de ([195.135.220.15]:44769 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755376Ab2ATUfH (ORCPT ); Fri, 20 Jan 2012 15:35:07 -0500 Received: from relay2.suse.de (unknown [195.135.220.254]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx2.suse.de (Postfix) with ESMTP id D1C4E8FFEB; Fri, 20 Jan 2012 21:35:05 +0100 (CET) Received: by quack.suse.cz (Postfix, from userid 1000) id 58C8C205E3; Fri, 20 Jan 2012 21:34:51 +0100 (CET) From: Jan Kara To: linux-fsdevel@vger.kernel.org Cc: Eric Sandeen , Dave Chinner , Surbhi Palande , Kamal Mostafa , Christoph Hellwig , LKML , xfs@oss.sgi.com, linux-ext4@vger.kernel.org, Jan Kara Subject: [PATCH 6/8] xfs: Use generic writers counter instead of m_active_trans counter Date: Fri, 20 Jan 2012 21:34:44 +0100 Message-Id: <1327091686-23177-7-git-send-email-jack@suse.cz> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1327091686-23177-1-git-send-email-jack@suse.cz> References: <1327091686-23177-1-git-send-email-jack@suse.cz> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org m_active_trans counter is racy wrt filesystem freezing. The patch replaces it with generic counter of running transactions which is properly synchronized with filesystem freezing. Things are a bit more complex because we need to log a dummy transaction and free block counters after the filesystem is frozen so we need to pass information to _xfs_trans_alloc() whether the transaction is part of filesystem freezing or not. Signed-off-by: Jan Kara --- fs/xfs/xfs_fsops.c | 5 +++-- fs/xfs/xfs_fsops.h | 2 +- fs/xfs/xfs_iomap.c | 4 ++-- fs/xfs/xfs_mount.c | 2 +- fs/xfs/xfs_mount.h | 2 -- fs/xfs/xfs_super.c | 3 +-- fs/xfs/xfs_sync.c | 13 +++---------- fs/xfs/xfs_trans.c | 19 ++++++++++++------- fs/xfs/xfs_trans.h | 3 ++- 9 files changed, 25 insertions(+), 28 deletions(-) diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c index 1c6fdeb..503fdfa 100644 --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -645,12 +645,13 @@ out: */ int xfs_fs_log_dummy( - xfs_mount_t *mp) + xfs_mount_t *mp, + bool for_freeze) { xfs_trans_t *tp; int error; - tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1, KM_SLEEP); + tp = _xfs_trans_alloc(mp, XFS_TRANS_DUMMY1, KM_SLEEP, for_freeze); error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0, XFS_DEFAULT_LOG_COUNT); if (error) { diff --git a/fs/xfs/xfs_fsops.h b/fs/xfs/xfs_fsops.h index 1b6a98b..4d6253e 100644 --- a/fs/xfs/xfs_fsops.h +++ b/fs/xfs/xfs_fsops.h @@ -25,6 +25,6 @@ extern int xfs_fs_counts(xfs_mount_t *mp, xfs_fsop_counts_t *cnt); extern int xfs_reserve_blocks(xfs_mount_t *mp, __uint64_t *inval, xfs_fsop_resblks_t *outval); extern int xfs_fs_goingdown(xfs_mount_t *mp, __uint32_t inflags); -extern int xfs_fs_log_dummy(struct xfs_mount *mp); +extern int xfs_fs_log_dummy(struct xfs_mount *mp, bool for_freeze); #endif /* __XFS_FSOPS_H__ */ diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index 9afa282..fd47f6e 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -679,8 +679,8 @@ xfs_iomap_write_unwritten( * the same inode that we complete here and might deadlock * on the iolock. */ - xfs_wait_for_freeze(mp, SB_FREEZE_TRANS); - tp = _xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE, KM_NOFS); + tp = _xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE, + KM_NOFS, false); tp->t_flags |= XFS_TRANS_RESERVE; error = xfs_trans_reserve(tp, resblks, XFS_WRITE_LOG_RES(mp), 0, diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c index d06afbc..74a93c9 100644 --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -1572,7 +1572,7 @@ xfs_log_sbcount(xfs_mount_t *mp) if (!xfs_sb_version_haslazysbcount(&mp->m_sb)) return 0; - tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP); + tp = _xfs_trans_alloc(mp, XFS_TRANS_SB_COUNT, KM_SLEEP, true); error = xfs_trans_reserve(tp, 0, mp->m_sb.sb_sectsize + 128, 0, 0, XFS_DEFAULT_LOG_COUNT); if (error) { diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h index bb24dac..1317018 100644 --- a/fs/xfs/xfs_mount.h +++ b/fs/xfs/xfs_mount.h @@ -195,7 +195,6 @@ typedef struct xfs_mount { uint m_chsize; /* size of next field */ struct xfs_chash *m_chash; /* fs private inode per-cluster * hash table */ - atomic_t m_active_trans; /* number trans frozen */ #ifdef HAVE_PERCPU_SB xfs_icsb_cnts_t __percpu *m_sb_cnts; /* per-cpu superblock counters */ unsigned long m_icsb_counters; /* disabled per-cpu counters */ @@ -312,7 +311,6 @@ void xfs_do_force_shutdown(struct xfs_mount *mp, int flags, char *fname, #define SHUTDOWN_DEVICE_REQ 0x0020 /* failed all paths to the device */ #define xfs_test_for_freeze(mp) ((mp)->m_super->s_frozen) -#define xfs_wait_for_freeze(mp,l) vfs_check_frozen((mp)->m_super, (l)) /* * Flags for xfs_mountfs diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 3eca58f..2c333be 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -1242,7 +1242,7 @@ xfs_fs_freeze( xfs_save_resvblks(mp); xfs_quiesce_attr(mp); - return -xfs_fs_log_dummy(mp); + return -xfs_fs_log_dummy(mp, true); } STATIC int @@ -1329,7 +1329,6 @@ xfs_fs_fill_super( spin_lock_init(&mp->m_sb_lock); mutex_init(&mp->m_growlock); - atomic_set(&mp->m_active_trans, 0); mp->m_super = sb; sb->s_fs_info = mp; diff --git a/fs/xfs/xfs_sync.c b/fs/xfs/xfs_sync.c index aa3dc1a..24f4d7c 100644 --- a/fs/xfs/xfs_sync.c +++ b/fs/xfs/xfs_sync.c @@ -373,7 +373,7 @@ xfs_quiesce_data( /* mark the log as covered if needed */ if (xfs_log_need_covered(mp)) - error2 = xfs_fs_log_dummy(mp); + error2 = xfs_fs_log_dummy(mp, false); /* flush data-only devices */ if (mp->m_rtdev_targp) @@ -421,18 +421,11 @@ xfs_quiesce_attr( int error = 0; /* wait for all modifications to complete */ - while (atomic_read(&mp->m_active_trans) > 0) - delay(100); + sb_wait_write(mp->m_super, SB_FREEZE_TRANS); /* flush inodes and push all remaining buffers out to disk */ xfs_quiesce_fs(mp); - /* - * Just warn here till VFS can correctly support - * read-only remount without racing. - */ - WARN_ON(atomic_read(&mp->m_active_trans) != 0); - /* Push the superblock and write an unmount record */ error = xfs_log_sbcount(mp); if (error) @@ -467,7 +460,7 @@ xfs_sync_worker( /* dgc: errors ignored here */ if (mp->m_super->s_frozen == SB_UNFROZEN && xfs_log_need_covered(mp)) - error = xfs_fs_log_dummy(mp); + error = xfs_fs_log_dummy(mp, false); else xfs_log_force(mp, 0); error = xfs_qm_sync(mp, SYNC_TRYLOCK); diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index 1f35b2f..e97014b 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -577,24 +577,28 @@ xfs_trans_alloc( xfs_mount_t *mp, uint type) { - xfs_wait_for_freeze(mp, SB_FREEZE_TRANS); - return _xfs_trans_alloc(mp, type, KM_SLEEP); + return _xfs_trans_alloc(mp, type, KM_SLEEP, false); } xfs_trans_t * _xfs_trans_alloc( xfs_mount_t *mp, uint type, - uint memflags) + uint memflags, + bool freezing) { xfs_trans_t *tp; - atomic_inc(&mp->m_active_trans); - + if (!freezing) + sb_start_write(mp->m_super, SB_FREEZE_TRANS); + else + WARN_ON(xfs_test_for_freeze(mp) != SB_FREEZE_TRANS); tp = kmem_zone_zalloc(xfs_trans_zone, memflags); tp->t_magic = XFS_TRANS_MAGIC; tp->t_type = type; tp->t_mountp = mp; + if (freezing) + tp->t_flags |= XFS_TRANS_FREEZING; INIT_LIST_HEAD(&tp->t_items); INIT_LIST_HEAD(&tp->t_busy); return tp; @@ -611,7 +615,8 @@ xfs_trans_free( xfs_alloc_busy_sort(&tp->t_busy); xfs_alloc_busy_clear(tp->t_mountp, &tp->t_busy, false); - atomic_dec(&tp->t_mountp->m_active_trans); + if (!(tp->t_flags & XFS_TRANS_FREEZING)) + sb_end_write(tp->t_mountp->m_super, SB_FREEZE_TRANS); xfs_trans_free_dqinfo(tp); kmem_zone_free(xfs_trans_zone, tp); } @@ -654,7 +659,7 @@ xfs_trans_dup( xfs_trans_dup_dqinfo(tp, ntp); - atomic_inc(&tp->t_mountp->m_active_trans); + sb_dup_write(tp->t_mountp->m_super, SB_FREEZE_TRANS); return ntp; } diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h index 3ae713c..8a04d8e 100644 --- a/fs/xfs/xfs_trans.h +++ b/fs/xfs/xfs_trans.h @@ -180,6 +180,7 @@ struct xfs_log_item_desc { #define XFS_TRANS_SYNC 0x08 /* make commit synchronous */ #define XFS_TRANS_DQ_DIRTY 0x10 /* at least one dquot in trx dirty */ #define XFS_TRANS_RESERVE 0x20 /* OK to use reserved data blocks */ +#define XFS_TRANS_FREEZING 0x40 /* can happen on frozen filesystem */ /* * Values for call flags parameter. @@ -448,7 +449,7 @@ typedef struct xfs_trans { * XFS transaction mechanism exported interfaces. */ xfs_trans_t *xfs_trans_alloc(struct xfs_mount *, uint); -xfs_trans_t *_xfs_trans_alloc(struct xfs_mount *, uint, uint); +xfs_trans_t *_xfs_trans_alloc(struct xfs_mount *, uint, uint, bool); xfs_trans_t *xfs_trans_dup(xfs_trans_t *); int xfs_trans_reserve(xfs_trans_t *, uint, uint, uint, uint, uint);