xfs: move the repair extent list into its own file

Move the xrep_extent_list code into a separate file.  Logically, this
data structure is really just a clumsy bitmap, and in the next patch
we'll make this more obvious.  No functional changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

1 files changed, 1 insertions, 193 deletions

diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c
index 5de1cac424ec..27a904ef6189 100644
--- a/fs/xfs/scrub/repair.c
+++ b/fs/xfs/scrub/repair.c
@@ -34,6 +34,7 @@
 #include "scrub/common.h"
 #include "scrub/trace.h"
 #include "scrub/repair.h"
+#include "scrub/bitmap.h"
 
 /*
  * Attempt to repair some metadata, if the metadata is corrupt and userspace
@@ -380,200 +381,7 @@ xrep_init_btblock(
  * sublist.  As with the other btrees we subtract sublist from exlist, and the
  * result (since the rmapbt lives in the free space) are the blocks from the
  * old rmapbt.
- */
-
-/* Collect a dead btree extent for later disposal. */
-int
-xrep_collect_btree_extent(
-	struct xfs_scrub	*sc,
-	struct xrep_extent_list	*exlist,
-	xfs_fsblock_t		fsbno,
-	xfs_extlen_t		len)
-{
-	struct xrep_extent	*rex;
-
-	trace_xrep_collect_btree_extent(sc->mp,
-			XFS_FSB_TO_AGNO(sc->mp, fsbno),
-			XFS_FSB_TO_AGBNO(sc->mp, fsbno), len);
-
-	rex = kmem_alloc(sizeof(struct xrep_extent), KM_MAYFAIL);
-	if (!rex)
-		return -ENOMEM;
-
-	INIT_LIST_HEAD(&rex->list);
-	rex->fsbno = fsbno;
-	rex->len = len;
-	list_add_tail(&rex->list, &exlist->list);
-
-	return 0;
-}
-
-/*
- * An error happened during the rebuild so the transaction will be cancelled.
- * The fs will shut down, and the administrator has to unmount and run repair.
- * Therefore, free all the memory associated with the list so we can die.
- */
-void
-xrep_cancel_btree_extents(
-	struct xfs_scrub	*sc,
-	struct xrep_extent_list	*exlist)
-{
-	struct xrep_extent	*rex;
-	struct xrep_extent	*n;
-
-	for_each_xrep_extent_safe(rex, n, exlist) {
-		list_del(&rex->list);
-		kmem_free(rex);
-	}
-}
-
-/* Compare two btree extents. */
-static int
-xrep_btree_extent_cmp(
-	void			*priv,
-	struct list_head	*a,
-	struct list_head	*b)
-{
-	struct xrep_extent	*ap;
-	struct xrep_extent	*bp;
-
-	ap = container_of(a, struct xrep_extent, list);
-	bp = container_of(b, struct xrep_extent, list);
-
-	if (ap->fsbno > bp->fsbno)
-		return 1;
-	if (ap->fsbno < bp->fsbno)
-		return -1;
-	return 0;
-}
-
-/*
- * Remove all the blocks mentioned in @sublist from the extents in @exlist.
  *
- * The intent is that callers will iterate the rmapbt for all of its records
- * for a given owner to generate @exlist; and iterate all the blocks of the
- * metadata structures that are not being rebuilt and have the same rmapbt
- * owner to generate @sublist.  This routine subtracts all the extents
- * mentioned in sublist from all the extents linked in @exlist, which leaves
- * @exlist as the list of blocks that are not accounted for, which we assume
- * are the dead blocks of the old metadata structure.  The blocks mentioned in
- * @exlist can be reaped.
- */
-#define LEFT_ALIGNED	(1 << 0)
-#define RIGHT_ALIGNED	(1 << 1)
-int
-xrep_subtract_extents(
-	struct xfs_scrub	*sc,
-	struct xrep_extent_list	*exlist,
-	struct xrep_extent_list	*sublist)
-{
-	struct list_head	*lp;
-	struct xrep_extent	*ex;
-	struct xrep_extent	*newex;
-	struct xrep_extent	*subex;
-	xfs_fsblock_t		sub_fsb;
-	xfs_extlen_t		sub_len;
-	int			state;
-	int			error = 0;
-
-	if (list_empty(&exlist->list) || list_empty(&sublist->list))
-		return 0;
-	ASSERT(!list_empty(&sublist->list));
-
-	list_sort(NULL, &exlist->list, xrep_btree_extent_cmp);
-	list_sort(NULL, &sublist->list, xrep_btree_extent_cmp);
-
-	/*
-	 * Now that we've sorted both lists, we iterate exlist once, rolling
-	 * forward through sublist and/or exlist as necessary until we find an
-	 * overlap or reach the end of either list.  We do not reset lp to the
-	 * head of exlist nor do we reset subex to the head of sublist.  The
-	 * list traversal is similar to merge sort, but we're deleting
-	 * instead.  In this manner we avoid O(n^2) operations.
-	 */
-	subex = list_first_entry(&sublist->list, struct xrep_extent,
-			list);
-	lp = exlist->list.next;
-	while (lp != &exlist->list) {
-		ex = list_entry(lp, struct xrep_extent, list);
-
-		/*
-		 * Advance subex and/or ex until we find a pair that
-		 * intersect or we run out of extents.
-		 */
-		while (subex->fsbno + subex->len <= ex->fsbno) {
-			if (list_is_last(&subex->list, &sublist->list))
-				goto out;
-			subex = list_next_entry(subex, list);
-		}
-		if (subex->fsbno >= ex->fsbno + ex->len) {
-			lp = lp->next;
-			continue;
-		}
-
-		/* trim subex to fit the extent we have */
-		sub_fsb = subex->fsbno;
-		sub_len = subex->len;
-		if (subex->fsbno < ex->fsbno) {
-			sub_len -= ex->fsbno - subex->fsbno;
-			sub_fsb = ex->fsbno;
-		}
-		if (sub_len > ex->len)
-			sub_len = ex->len;
-
-		state = 0;
-		if (sub_fsb == ex->fsbno)
-			state |= LEFT_ALIGNED;
-		if (sub_fsb + sub_len == ex->fsbno + ex->len)
-			state |= RIGHT_ALIGNED;
-		switch (state) {
-		case LEFT_ALIGNED:
-			/* Coincides with only the left. */
-			ex->fsbno += sub_len;
-			ex->len -= sub_len;
-			break;
-		case RIGHT_ALIGNED:
-			/* Coincides with only the right. */
-			ex->len -= sub_len;
-			lp = lp->next;
-			break;
-		case LEFT_ALIGNED | RIGHT_ALIGNED:
-			/* Total overlap, just delete ex. */
-			lp = lp->next;
-			list_del(&ex->list);
-			kmem_free(ex);
-			break;
-		case 0:
-			/*
-			 * Deleting from the middle: add the new right extent
-			 * and then shrink the left extent.
-			 */
-			newex = kmem_alloc(sizeof(struct xrep_extent),
-					KM_MAYFAIL);
-			if (!newex) {
-				error = -ENOMEM;
-				goto out;
-			}
-			INIT_LIST_HEAD(&newex->list);
-			newex->fsbno = sub_fsb + sub_len;
-			newex->len = ex->fsbno + ex->len - newex->fsbno;
-			list_add(&newex->list, &ex->list);
-			ex->len = sub_fsb - ex->fsbno;
-			lp = lp->next;
-			break;
-		default:
-			ASSERT(0);
-			break;
-		}
-	}
-
-out:
-	return error;
-}
-#undef LEFT_ALIGNED
-#undef RIGHT_ALIGNED
-
-/*
  * Disposal of Blocks from Old per-AG Btrees
  *
  * Now that we've constructed a new btree to replace the damaged one, we want