Merge tag 'xfs-4.12-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/x…

…fs-linux

Pull XFS fixes from Darrick Wong:
 "A few miscellaneous bug fixes & cleanups:

   - Fix indlen block reservation accounting bug when splitting delalloc
     extent

   - Fix warnings about unused variables that appeared in -rc1.

   - Don't spew errors when bmapping a local format directory

   - Fix an off-by-one error in a delalloc eof assertion

   - Make fsmap only return inode information for CAP_SYS_ADMIN

   - Fix a potential mount time deadlock recovering cow extents

   - Fix unaligned memory access in _btree_visit_blocks

   - Fix various SEEK_HOLE/SEEK_DATA bugs"

* tag 'xfs-4.12-fixes-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: Move handling of missing page into one place in xfs_find_get_desired_pgoff()
  xfs: Fix off-by-in in loop termination in xfs_find_get_desired_pgoff()
  xfs: Fix missed holes in SEEK_HOLE implementation
  xfs: fix off-by-one on max nr_pages in xfs_find_get_desired_pgoff()
  xfs: fix unaligned access in xfs_btree_visit_blocks
  xfs: avoid mount-time deadlock in CoW extent recovery
  xfs: only return detailed fsmap info if the caller has CAP_SYS_ADMIN
  xfs: bad assertion for delalloc an extent that start at i_size
  xfs: fix warnings about unused stack variables
  xfs: BMAPX shouldn't barf on inline-format directories
  xfs: fix indlen accounting error on partial delalloc conversion

fs/xfs/libxfs/xfs_bmap.c

@@ -1280,7 +1280,6 @@ xfs_bmap_read_extents(
 		xfs_bmbt_rec_t	*frp;
 		xfs_fsblock_t	nextbno;
 		xfs_extnum_t	num_recs;
-		xfs_extnum_t	start;
 
 		num_recs = xfs_btree_get_numrecs(block);
 		if (unlikely(i + num_recs > room)) {
@@ -1303,7 +1302,6 @@ xfs_bmap_read_extents(
 		 * Copy records into the extent records.
 		 */
 		frp = XFS_BMBT_REC_ADDR(mp, block, 1);
-		start = i;
 		for (j = 0; j < num_recs; j++, i++, frp++) {
 			xfs_bmbt_rec_host_t *trp = xfs_iext_get_ext(ifp, i);
 			trp->l0 = be64_to_cpu(frp->l0);
@@ -2065,8 +2063,10 @@ xfs_bmap_add_extent_delay_real(
 		}
 		temp = xfs_bmap_worst_indlen(bma->ip, temp);
 		temp2 = xfs_bmap_worst_indlen(bma->ip, temp2);
-		diff = (int)(temp + temp2 - startblockval(PREV.br_startblock) -
-			(bma->cur ? bma->cur->bc_private.b.allocated : 0));
+		diff = (int)(temp + temp2 -
+			     (startblockval(PREV.br_startblock) -
+			      (bma->cur ?
+			       bma->cur->bc_private.b.allocated : 0)));
 		if (diff > 0) {
 			error = xfs_mod_fdblocks(bma->ip->i_mount,
 						 -((int64_t)diff), false);
@@ -2123,7 +2123,6 @@ xfs_bmap_add_extent_delay_real(
 		temp = da_new;
 		if (bma->cur)
 			temp += bma->cur->bc_private.b.allocated;
-		ASSERT(temp <= da_old);
 		if (temp < da_old)
 			xfs_mod_fdblocks(bma->ip->i_mount,
 					(int64_t)(da_old - temp), false);

fs/xfs/libxfs/xfs_btree.c

@@ -4395,7 +4395,7 @@ xfs_btree_visit_blocks(
 			xfs_btree_readahead_ptr(cur, ptr, 1);
 
 			/* save for the next iteration of the loop */
-			lptr = *ptr;
+			xfs_btree_copy_ptrs(cur, &lptr, ptr, 1);
 		}
 
 		/* for each buffer in the level */

fs/xfs/libxfs/xfs_refcount.c

@@ -1629,13 +1629,28 @@ xfs_refcount_recover_cow_leftovers(
 	if (mp->m_sb.sb_agblocks >= XFS_REFC_COW_START)
 		return -EOPNOTSUPP;
 
-	error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp);
+	INIT_LIST_HEAD(&debris);
+
+	/*
+	 * In this first part, we use an empty transaction to gather up
+	 * all the leftover CoW extents so that we can subsequently
+	 * delete them.  The empty transaction is used to avoid
+	 * a buffer lock deadlock if there happens to be a loop in the
+	 * refcountbt because we're allowed to re-grab a buffer that is
+	 * already attached to our transaction.  When we're done
+	 * recording the CoW debris we cancel the (empty) transaction
+	 * and everything goes away cleanly.
+	 */
+	error = xfs_trans_alloc_empty(mp, &tp);
 	if (error)
 		return error;
-	cur = xfs_refcountbt_init_cursor(mp, NULL, agbp, agno, NULL);
+
+	error = xfs_alloc_read_agf(mp, tp, agno, 0, &agbp);
+	if (error)
+		goto out_trans;
+	cur = xfs_refcountbt_init_cursor(mp, tp, agbp, agno, NULL);
 
 	/* Find all the leftover CoW staging extents. */
-	INIT_LIST_HEAD(&debris);
 	memset(&low, 0, sizeof(low));
 	memset(&high, 0, sizeof(high));
 	low.rc.rc_startblock = XFS_REFC_COW_START;
@@ -1645,10 +1660,11 @@ xfs_refcount_recover_cow_leftovers(
 	if (error)
 		goto out_cursor;
 	xfs_btree_del_cursor(cur, XFS_BTREE_NOERROR);
-	xfs_buf_relse(agbp);
+	xfs_trans_brelse(tp, agbp);
+	xfs_trans_cancel(tp);
 
 	/* Now iterate the list to free the leftovers */
-	list_for_each_entry(rr, &debris, rr_list) {
+	list_for_each_entry_safe(rr, n, &debris, rr_list) {
 		/* Set up transaction. */
 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp);
 		if (error)
@@ -1676,8 +1692,16 @@ xfs_refcount_recover_cow_leftovers(
 		error = xfs_trans_commit(tp);
 		if (error)
 			goto out_free;
+
+		list_del(&rr->rr_list);
+		kmem_free(rr);
 	}
 
+	return error;
+out_defer:
+	xfs_defer_cancel(&dfops);
+out_trans:
+	xfs_trans_cancel(tp);
 out_free:
 	/* Free the leftover list */
 	list_for_each_entry_safe(rr, n, &debris, rr_list) {
@@ -1688,11 +1712,6 @@ xfs_refcount_recover_cow_leftovers(
 
 out_cursor:
 	xfs_btree_del_cursor(cur, XFS_BTREE_ERROR);
-	xfs_buf_relse(agbp);
-	goto out_free;
-
-out_defer:
-	xfs_defer_cancel(&dfops);
-	xfs_trans_cancel(tp);
-	goto out_free;
+	xfs_trans_brelse(tp, agbp);
+	goto out_trans;
 }

fs/xfs/xfs_bmap_util.c

@@ -582,9 +582,13 @@ xfs_getbmap(
 		}
 		break;
 	default:
+		/* Local format data forks report no extents. */
+		if (ip->i_d.di_format == XFS_DINODE_FMT_LOCAL) {
+			bmv->bmv_entries = 0;
+			return 0;
+		}
 		if (ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS &&
-		    ip->i_d.di_format != XFS_DINODE_FMT_BTREE &&
-		    ip->i_d.di_format != XFS_DINODE_FMT_LOCAL)
+		    ip->i_d.di_format != XFS_DINODE_FMT_BTREE)
 			return -EINVAL;
 
 		if (xfs_get_extsz_hint(ip) ||
@@ -712,7 +716,7 @@ xfs_getbmap(
 			 * extents.
 			 */
 			if (map[i].br_startblock == DELAYSTARTBLOCK &&
-			    map[i].br_startoff <= XFS_B_TO_FSB(mp, XFS_ISIZE(ip)))
+			    map[i].br_startoff < XFS_B_TO_FSB(mp, XFS_ISIZE(ip)))
 				ASSERT((iflags & BMV_IF_DELALLOC) != 0);
 
                         if (map[i].br_startblock == HOLESTARTBLOCK &&

fs/xfs/xfs_file.c

@@ -1043,49 +1043,17 @@ xfs_find_get_desired_pgoff(
 
 	index = startoff >> PAGE_SHIFT;
 	endoff = XFS_FSB_TO_B(mp, map->br_startoff + map->br_blockcount);
-	end = endoff >> PAGE_SHIFT;
+	end = (endoff - 1) >> PAGE_SHIFT;
 	do {
 		int		want;
 		unsigned	nr_pages;
 		unsigned int	i;
 
-		want = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
+		want = min_t(pgoff_t, end - index, PAGEVEC_SIZE - 1) + 1;
 		nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
 					  want);
-		/*
-		 * No page mapped into given range.  If we are searching holes
-		 * and if this is the first time we got into the loop, it means
-		 * that the given offset is landed in a hole, return it.
-		 *
-		 * If we have already stepped through some block buffers to find
-		 * holes but they all contains data.  In this case, the last
-		 * offset is already updated and pointed to the end of the last
-		 * mapped page, if it does not reach the endpoint to search,
-		 * that means there should be a hole between them.
-		 */
-		if (nr_pages == 0) {
-			/* Data search found nothing */
-			if (type == DATA_OFF)
-				break;
-
-			ASSERT(type == HOLE_OFF);
-			if (lastoff == startoff || lastoff < endoff) {
-				found = true;
-				*offset = lastoff;
-			}
-			break;
-		}
-
-		/*
-		 * At lease we found one page.  If this is the first time we
-		 * step into the loop, and if the first page index offset is
-		 * greater than the given search offset, a hole was found.
-		 */
-		if (type == HOLE_OFF && lastoff == startoff &&
-		    lastoff < page_offset(pvec.pages[0])) {
-			found = true;
+		if (nr_pages == 0)
 			break;
-		}
 
 		for (i = 0; i < nr_pages; i++) {
 			struct page	*page = pvec.pages[i];
@@ -1098,18 +1066,18 @@ xfs_find_get_desired_pgoff(
 			 * file mapping. However, page->index will not change
 			 * because we have a reference on the page.
 			 *
-			 * Searching done if the page index is out of range.
-			 * If the current offset is not reaches the end of
-			 * the specified search range, there should be a hole
-			 * between them.
+			 * If current page offset is beyond where we've ended,
+			 * we've found a hole.
 			 */
-			if (page->index > end) {
-				if (type == HOLE_OFF && lastoff < endoff) {
-					*offset = lastoff;
-					found = true;
-				}
+			if (type == HOLE_OFF && lastoff < endoff &&
+			    lastoff < page_offset(pvec.pages[i])) {
+				found = true;
+				*offset = lastoff;
 				goto out;
 			}
+			/* Searching done if the page index is out of range. */
+			if (page->index > end)
+				goto out;
 
 			lock_page(page);
 			/*
@@ -1151,21 +1119,20 @@ xfs_find_get_desired_pgoff(
 
 		/*
 		 * The number of returned pages less than our desired, search
-		 * done.  In this case, nothing was found for searching data,
-		 * but we found a hole behind the last offset.
+		 * done.
 		 */
-		if (nr_pages < want) {
-			if (type == HOLE_OFF) {
-				*offset = lastoff;
-				found = true;
-			}
+		if (nr_pages < want)
 			break;
-		}
 
 		index = pvec.pages[i - 1]->index + 1;
 		pagevec_release(&pvec);
 	} while (index <= end);
 
+	/* No page at lastoff and we are not done - we found a hole. */
+	if (type == HOLE_OFF && lastoff < endoff) {
+		*offset = lastoff;
+		found = true;
+	}
 out:
 	pagevec_release(&pvec);
 	return found;

fs/xfs/xfs_fsmap.c

@@ -828,6 +828,7 @@ xfs_getfsmap(
 	struct xfs_fsmap		dkeys[2];	/* per-dev keys */
 	struct xfs_getfsmap_dev		handlers[XFS_GETFSMAP_DEVS];
 	struct xfs_getfsmap_info	info = { NULL };
+	bool				use_rmap;
 	int				i;
 	int				error = 0;
 
@@ -837,12 +838,14 @@ xfs_getfsmap(
 	    !xfs_getfsmap_is_valid_device(mp, &head->fmh_keys[1]))
 		return -EINVAL;
 
+	use_rmap = capable(CAP_SYS_ADMIN) &&
+		   xfs_sb_version_hasrmapbt(&mp->m_sb);
 	head->fmh_entries = 0;
 
 	/* Set up our device handlers. */
 	memset(handlers, 0, sizeof(handlers));
 	handlers[0].dev = new_encode_dev(mp->m_ddev_targp->bt_dev);
-	if (xfs_sb_version_hasrmapbt(&mp->m_sb))
+	if (use_rmap)
 		handlers[0].fn = xfs_getfsmap_datadev_rmapbt;
 	else
 		handlers[0].fn = xfs_getfsmap_datadev_bnobt;