[PATCH 14/34] xfs: fix EFI transaction cancellation.

Dave Chinner
2010-12-21T07:28:36Z

XFS_EFI_CANCELED has not been set in the code base since
xfs_efi_cancel() was removed back in 2006 by commit
065d312e15902976d256ddaf396a7950ec0350a8 ("[XFS] Remove unused
iop_abort log item operation), and even then xfs_efi_cancel() was
never called. I haven't tracked it back further than that (beyond
git history), but it indicates that the handling of EFIs in
cancelled transactions has been broken for a long time.

Basically, when we get an IOP_UNPIN(lip, 1); call from
xfs_trans_uncommit() (i.e. remove == 1), if we don't free the log
item descriptor we leak it. Fix the behviour to be correct and kill
the XFS_EFI_CANCELED flag.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/xfs_extfree_item.c | 20 +++++++++-----------
fs/xfs/xfs_extfree_item.h | 1 -
2 files changed, 9 insertions(+), 12 deletions(-)

diff --git a/fs/xfs/xfs_extfree_item.c b/fs/xfs/xfs_extfree_item.c
index a55e687..5997efa 100644
--- a/fs/xfs/xfs_extfree_item.c
+++ b/fs/xfs/xfs_extfree_item.c
@@ -99,10 +99,11 @@ xfs_efi_item_pin(
}

/*
- * While EFIs cannot really be pinned, the unpin operation is the
- * last place at which the EFI is manipulated during a transaction.
- * Here we coordinate with xfs_efi_cancel() to determine who gets to
- * free the EFI.
+ * While EFIs cannot really be pinned, the unpin operation is the last place at
+ * which the EFI is manipulated during a transaction. If we are being asked to
+ * remove the EFI it's because the transaction has been cancelled and by
+ * definition that means the EFI cannot be in the AIL so remove it from the
+ * transaction and free it.
*/
STATIC void
xfs_efi_item_unpin(
@@ -113,17 +114,14 @@ xfs_efi_item_unpin(
struct xfs_ail *ailp = lip->li_ailp;

spin_lock(&ailp->xa_lock);
- if (efip->efi_flags & XFS_EFI_CANCELED) {
- if (remove)
- xfs_trans_del_item(lip);
-
- /* xfs_trans_ail_delete() drops the AIL lock. */
- xfs_trans_ail_delete(ailp, lip);
+ if (remove) {
+ ASSERT(!(lip->li_flags & XFS_LI_IN_AIL));
+ xfs_trans_del_item(lip);
xfs_efi_item_free(efip);
} else {
efip->efi_flags |= XFS_EFI_COMMITTED;
- spin_unlock(&ailp->xa_lock);
}
+ spin_unlock(&ailp->xa_lock);
}

/*
diff --git a/fs/xfs/xfs_extfree_item.h b/fs/xfs/xfs_extfree_item.h
index 0d22c56..f7834ec 100644
--- a/fs/xfs/xfs_extfree_item.h
+++ b/fs/xfs/xfs_extfree_item.h
@@ -115,7 +115,6 @@ typedef struct xfs_efd_log_format_64 {
*/
#define XFS_EFI_RECOVERED 0x1
#define XFS_EFI_COMMITTED 0x2
-#define XFS_EFI_CANCELED 0x4

/*
* This is the "extent free intention" log item. It is used