From: Allison Henderson <allison.henderson@oracle.com>
To: linux-xfs@vger.kernel.org
Subject: [PATCH v25 01/12] xfs: Fix double unlock in defer capture code
Date: Tue, 16 Nov 2021 21:13:32 -0700 [thread overview]
Message-ID: <20211117041343.3050202-2-allison.henderson@oracle.com> (raw)
In-Reply-To: <20211117041343.3050202-1-allison.henderson@oracle.com>
The new deferred attr patch set uncovered a double unlock in the
recent port of the defer ops capture and continue code. During log
recovery, we're allowed to hold buffers to a transaction that's being
used to replay an intent item. When we capture the resources as part
of scheduling a continuation of an intent chain, we call xfs_buf_hold
to retain our reference to the buffer beyond the transaction commit,
but we do /not/ call xfs_trans_bhold to maintain the buffer lock.
This means that xfs_defer_ops_continue needs to relock the buffers
before xfs_defer_restore_resources joins then tothe new transaction.
Additionally, the buffers should not be passed back via the dres
structure since they need to remain locked unlike the inodes. So
simply set dr_bufs to zero after populating the dres structure.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
---
fs/xfs/libxfs/xfs_defer.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c
index 0805ade2d300..6dac8d6b8c21 100644
--- a/fs/xfs/libxfs/xfs_defer.c
+++ b/fs/xfs/libxfs/xfs_defer.c
@@ -22,6 +22,7 @@
#include "xfs_refcount.h"
#include "xfs_bmap.h"
#include "xfs_alloc.h"
+#include "xfs_buf.h"
static struct kmem_cache *xfs_defer_pending_cache;
@@ -774,17 +775,25 @@ xfs_defer_ops_continue(
struct xfs_trans *tp,
struct xfs_defer_resources *dres)
{
+ unsigned int i;
+
ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
ASSERT(!(tp->t_flags & XFS_TRANS_DIRTY));
- /* Lock and join the captured inode to the new transaction. */
+ /* Lock the captured resources to the new transaction. */
if (dfc->dfc_held.dr_inos == 2)
xfs_lock_two_inodes(dfc->dfc_held.dr_ip[0], XFS_ILOCK_EXCL,
dfc->dfc_held.dr_ip[1], XFS_ILOCK_EXCL);
else if (dfc->dfc_held.dr_inos == 1)
xfs_ilock(dfc->dfc_held.dr_ip[0], XFS_ILOCK_EXCL);
+
+ for (i = 0; i < dfc->dfc_held.dr_bufs; i++)
+ xfs_buf_lock(dfc->dfc_held.dr_bp[i]);
+
+ /* Join the captured resources to the new transaction. */
xfs_defer_restore_resources(tp, &dfc->dfc_held);
memcpy(dres, &dfc->dfc_held, sizeof(struct xfs_defer_resources));
+ dres->dr_bufs = 0;
/* Move captured dfops chain and state to the transaction. */
list_splice_init(&dfc->dfc_dfops, &tp->t_dfops);
--
2.25.1
next prev parent reply other threads:[~2021-11-17 4:13 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-17 4:13 [PATCH v25 00/12] Log Attribute Replay Allison Henderson
2021-11-17 4:13 ` Allison Henderson [this message]
2021-11-17 4:13 ` [PATCH v25 02/12] xfs: don't commit the first deferred transaction without intents Allison Henderson
2021-11-23 23:28 ` Darrick J. Wong
2021-12-01 7:34 ` Allison Henderson
2021-11-17 4:13 ` [PATCH v25 03/12] xfs: Return from xfs_attr_set_iter if there are no more rmtblks to process Allison Henderson
2021-11-17 4:13 ` [PATCH v25 04/12] xfs: Set up infrastructure for log attribute replay Allison Henderson
2021-11-23 23:50 ` Darrick J. Wong
2021-12-01 7:35 ` Allison Henderson
2021-11-17 4:13 ` [PATCH v25 05/12] xfs: Implement attr logging and replay Allison Henderson
2021-11-24 0:11 ` Darrick J. Wong
2021-12-01 7:34 ` Allison Henderson
2021-12-01 17:52 ` Darrick J. Wong
2021-11-17 4:13 ` [PATCH v25 06/12] xfs: Skip flip flags for delayed attrs Allison Henderson
2021-11-17 4:13 ` [PATCH v25 07/12] xfs: Add xfs_attr_set_deferred and xfs_attr_remove_deferred Allison Henderson
2021-11-17 4:13 ` [PATCH v25 08/12] xfs: Remove unused xfs_attr_*_args Allison Henderson
2021-11-17 4:13 ` [PATCH v25 09/12] xfs: Add log attribute error tag Allison Henderson
2021-11-17 4:13 ` [PATCH v25 10/12] xfs: Add larp debug option Allison Henderson
2021-11-23 23:29 ` Darrick J. Wong
2021-12-01 7:34 ` Allison Henderson
2021-11-17 4:13 ` [PATCH v25 11/12] xfs: Merge xfs_delattr_context into xfs_attr_item Allison Henderson
2021-11-17 4:13 ` [PATCH v25 12/12] xfs: Add helper function xfs_attr_leaf_addname Allison Henderson
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