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authorBrian Foster <bfoster@redhat.com>2017-09-17 14:07:00 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-09-20 08:20:01 +0200
commitba986b3c84987bbc5e52d8ab83a851e613ce4001 (patch)
tree51af5317cf3d60adfc8d575b9a2e61ba5a7e488d
parent0f5af7eae8846fd73d01ecbe0d60309560084a74 (diff)
downloadlinux-linaro-stable-ba986b3c84987bbc5e52d8ab83a851e613ce4001.tar.gz
xfs: remove unnecessary dirty bli format check for ordered bufs
commit 6453c65d3576bc3e602abb5add15f112755c08ca upstream. xfs_buf_item_unlock() historically checked the dirty state of the buffer by manually checking the buffer log formats for dirty segments. The introduction of ordered buffers invalidated this check because ordered buffers have dirty bli's but no dirty (logged) segments. The check was updated to accommodate ordered buffers by looking at the bli state first and considering the blf only if the bli is clean. This logic is safe but unnecessary. There is no valid case where the bli is clean yet the blf has dirty segments. The bli is set dirty whenever the blf is logged (via xfs_trans_log_buf()) and the blf is cleared in the only place BLI_DIRTY is cleared (xfs_trans_binval()). Remove the conditional blf dirty checks and replace with an assert that should catch any discrepencies between bli and blf dirty states. Refactor the old blf dirty check into a helper function to be used by the assert. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/xfs/xfs_buf_item.c62
-rw-r--r--fs/xfs/xfs_buf_item.h1
2 files changed, 33 insertions, 30 deletions
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index cdae0ad5e0a5..ff076d11804a 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -575,26 +575,18 @@ xfs_buf_item_unlock(
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
struct xfs_buf *bp = bip->bli_buf;
- bool clean;
- bool aborted;
- int flags;
+ bool aborted = !!(lip->li_flags & XFS_LI_ABORTED);
+ bool hold = !!(bip->bli_flags & XFS_BLI_HOLD);
+ bool dirty = !!(bip->bli_flags & XFS_BLI_DIRTY);
+ bool ordered = !!(bip->bli_flags & XFS_BLI_ORDERED);
/* Clear the buffer's association with this transaction. */
bp->b_transp = NULL;
/*
- * If this is a transaction abort, don't return early. Instead, allow
- * the brelse to happen. Normally it would be done for stale
- * (cancelled) buffers at unpin time, but we'll never go through the
- * pin/unpin cycle if we abort inside commit.
+ * The per-transaction state has been copied above so clear it from the
+ * bli.
*/
- aborted = (lip->li_flags & XFS_LI_ABORTED) ? true : false;
- /*
- * Before possibly freeing the buf item, copy the per-transaction state
- * so we can reference it safely later after clearing it from the
- * buffer log item.
- */
- flags = bip->bli_flags;
bip->bli_flags &= ~(XFS_BLI_LOGGED | XFS_BLI_HOLD | XFS_BLI_ORDERED);
/*
@@ -602,7 +594,7 @@ xfs_buf_item_unlock(
* unlock the buffer and free the buf item when the buffer is unpinned
* for the last time.
*/
- if (flags & XFS_BLI_STALE) {
+ if (bip->bli_flags & XFS_BLI_STALE) {
trace_xfs_buf_item_unlock_stale(bip);
ASSERT(bip->__bli_format.blf_flags & XFS_BLF_CANCEL);
if (!aborted) {
@@ -620,20 +612,11 @@ xfs_buf_item_unlock(
* regardless of whether it is dirty or not. A dirty abort implies a
* shutdown, anyway.
*
- * Ordered buffers are dirty but may have no recorded changes, so ensure
- * we only release clean items here.
+ * The bli dirty state should match whether the blf has logged segments
+ * except for ordered buffers, where only the bli should be dirty.
*/
- clean = (flags & XFS_BLI_DIRTY) ? false : true;
- if (clean) {
- int i;
- for (i = 0; i < bip->bli_format_count; i++) {
- if (!xfs_bitmap_empty(bip->bli_formats[i].blf_data_map,
- bip->bli_formats[i].blf_map_size)) {
- clean = false;
- break;
- }
- }
- }
+ ASSERT((!ordered && dirty == xfs_buf_item_dirty_format(bip)) ||
+ (ordered && dirty && !xfs_buf_item_dirty_format(bip)));
/*
* Clean buffers, by definition, cannot be in the AIL. However, aborted
@@ -652,11 +635,11 @@ xfs_buf_item_unlock(
ASSERT(XFS_FORCED_SHUTDOWN(lip->li_mountp));
xfs_trans_ail_remove(lip, SHUTDOWN_LOG_IO_ERROR);
xfs_buf_item_relse(bp);
- } else if (clean)
+ } else if (!dirty)
xfs_buf_item_relse(bp);
}
- if (!(flags & XFS_BLI_HOLD))
+ if (!hold)
xfs_buf_relse(bp);
}
@@ -945,6 +928,25 @@ xfs_buf_item_log(
}
+/*
+ * Return true if the buffer has any ranges logged/dirtied by a transaction,
+ * false otherwise.
+ */
+bool
+xfs_buf_item_dirty_format(
+ struct xfs_buf_log_item *bip)
+{
+ int i;
+
+ for (i = 0; i < bip->bli_format_count; i++) {
+ if (!xfs_bitmap_empty(bip->bli_formats[i].blf_data_map,
+ bip->bli_formats[i].blf_map_size))
+ return true;
+ }
+
+ return false;
+}
+
STATIC void
xfs_buf_item_free(
xfs_buf_log_item_t *bip)
diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h
index e0e744aefaa8..9690ce62c9a7 100644
--- a/fs/xfs/xfs_buf_item.h
+++ b/fs/xfs/xfs_buf_item.h
@@ -64,6 +64,7 @@ typedef struct xfs_buf_log_item {
int xfs_buf_item_init(struct xfs_buf *, struct xfs_mount *);
void xfs_buf_item_relse(struct xfs_buf *);
void xfs_buf_item_log(xfs_buf_log_item_t *, uint, uint);
+bool xfs_buf_item_dirty_format(struct xfs_buf_log_item *);
void xfs_buf_attach_iodone(struct xfs_buf *,
void(*)(struct xfs_buf *, xfs_log_item_t *),
xfs_log_item_t *);