1 files changed, 143 insertions, 81 deletions

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 4bcc095fe44a..eef466260d43 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -1,19 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2000-2002,2005 Silicon Graphics, Inc.
  * All Rights Reserved.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it would be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write the Free Software Foundation,
- * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 #include "xfs.h"
 #include "xfs_fs.h"
@@ -39,6 +27,9 @@
 #include "xfs_buf_item.h"
 #include "xfs_log.h"
 #include "xfs_ag_resv.h"
+#include "xfs_bmap.h"
+
+extern kmem_zone_t	*xfs_bmap_free_item_zone;
 
 struct workqueue_struct *xfs_alloc_wq;
 
@@ -224,15 +215,37 @@ xfs_alloc_get_rec(
 	xfs_extlen_t		*len,	/* output: length of extent */
 	int			*stat)	/* output: success/failure */
 {
+	struct xfs_mount	*mp = cur->bc_mp;
+	xfs_agnumber_t		agno = cur->bc_private.a.agno;
 	union xfs_btree_rec	*rec;
 	int			error;
 
 	error = xfs_btree_get_rec(cur, &rec, stat);
-	if (!error && *stat == 1) {
-		*bno = be32_to_cpu(rec->alloc.ar_startblock);
-		*len = be32_to_cpu(rec->alloc.ar_blockcount);
-	}
-	return error;
+	if (error || !(*stat))
+		return error;
+	if (rec->alloc.ar_blockcount == 0)
+		goto out_bad_rec;
+
+	*bno = be32_to_cpu(rec->alloc.ar_startblock);
+	*len = be32_to_cpu(rec->alloc.ar_blockcount);
+
+	/* check for valid extent range, including overflow */
+	if (!xfs_verify_agbno(mp, agno, *bno))
+		goto out_bad_rec;
+	if (*bno > *bno + *len)
+		goto out_bad_rec;
+	if (!xfs_verify_agbno(mp, agno, *bno + *len - 1))
+		goto out_bad_rec;
+
+	return 0;
+
+out_bad_rec:
+	xfs_warn(mp,
+		"%s Freespace BTree record corruption in AG %d detected!",
+		cur->bc_btnum == XFS_BTNUM_BNO ? "Block" : "Size", agno);
+	xfs_warn(mp,
+		"start block 0x%x block count 0x%x", *bno, *len);
+	return -EFSCORRUPTED;
 }
 
 /*
@@ -2060,6 +2073,30 @@ xfs_alloc_space_available(
 	return true;
 }
 
+int
+xfs_free_agfl_block(
+	struct xfs_trans	*tp,
+	xfs_agnumber_t		agno,
+	xfs_agblock_t		agbno,
+	struct xfs_buf		*agbp,
+	struct xfs_owner_info	*oinfo)
+{
+	int			error;
+	struct xfs_buf		*bp;
+
+	error = xfs_free_ag_extent(tp, agbp, agno, agbno, 1, oinfo,
+				   XFS_AG_RESV_AGFL);
+	if (error)
+		return error;
+
+	bp = xfs_btree_get_bufs(tp->t_mountp, tp, agno, agbno, 0);
+	if (!bp)
+		return -EFSCORRUPTED;
+	xfs_trans_binval(tp, bp);
+
+	return 0;
+}
+
 /*
  * Check the agfl fields of the agf for inconsistency or corruption. The purpose
  * is to detect an agfl header padding mismatch between current and early v5
@@ -2148,6 +2185,40 @@ xfs_agfl_reset(
 }
 
 /*
+ * Defer an AGFL block free. This is effectively equivalent to
+ * xfs_bmap_add_free() with some special handling particular to AGFL blocks.
+ *
+ * Deferring AGFL frees helps prevent log reservation overruns due to too many
+ * allocation operations in a transaction. AGFL frees are prone to this problem
+ * because for one they are always freed one at a time. Further, an immediate
+ * AGFL block free can cause a btree join and require another block free before
+ * the real allocation can proceed. Deferring the free disconnects freeing up
+ * the AGFL slot from freeing the block.
+ */
+STATIC void
+xfs_defer_agfl_block(
+	struct xfs_mount		*mp,
+	struct xfs_defer_ops		*dfops,
+	xfs_agnumber_t			agno,
+	xfs_fsblock_t			agbno,
+	struct xfs_owner_info		*oinfo)
+{
+	struct xfs_extent_free_item	*new;		/* new element */
+
+	ASSERT(xfs_bmap_free_item_zone != NULL);
+	ASSERT(oinfo != NULL);
+
+	new = kmem_zone_alloc(xfs_bmap_free_item_zone, KM_SLEEP);
+	new->xefi_startblock = XFS_AGB_TO_FSB(mp, agno, agbno);
+	new->xefi_blockcount = 1;
+	new->xefi_oinfo = *oinfo;
+
+	trace_xfs_agfl_free_defer(mp, agno, 0, agbno, 1);
+
+	xfs_defer_add(dfops, XFS_DEFER_OPS_TYPE_AGFL_FREE, &new->xefi_list);
+}
+
+/*
  * Decide whether to use this allocation group for this allocation.
  * If so, fix up the btree freelist's size.
  */
@@ -2247,21 +2318,20 @@ xfs_alloc_fix_freelist(
 	else
 		xfs_rmap_ag_owner(&targs.oinfo, XFS_RMAP_OWN_AG);
 	while (!(flags & XFS_ALLOC_FLAG_NOSHRINK) && pag->pagf_flcount > need) {
-		struct xfs_buf	*bp;
-
 		error = xfs_alloc_get_freelist(tp, agbp, &bno, 0);
 		if (error)
 			goto out_agbp_relse;
-		error = xfs_free_ag_extent(tp, agbp, args->agno, bno, 1,
-					   &targs.oinfo, XFS_AG_RESV_AGFL);
-		if (error)
-			goto out_agbp_relse;
-		bp = xfs_btree_get_bufs(mp, tp, args->agno, bno, 0);
-		if (!bp) {
-			error = -EFSCORRUPTED;
-			goto out_agbp_relse;
+
+		/* defer agfl frees if dfops is provided */
+		if (tp->t_agfl_dfops) {
+			xfs_defer_agfl_block(mp, tp->t_agfl_dfops, args->agno,
+					     bno, &targs.oinfo);
+		} else {
+			error = xfs_free_agfl_block(tp, args->agno, bno, agbp,
+						    &targs.oinfo);
+			if (error)
+				goto out_agbp_relse;
 		}
-		xfs_trans_binval(tp, bp);
 	}
 
 	targs.tp = tp;
@@ -2949,18 +3019,20 @@ out:
  * after fixing up the freelist.
  */
 int				/* error */
-xfs_free_extent(
+__xfs_free_extent(
 	struct xfs_trans	*tp,	/* transaction pointer */
 	xfs_fsblock_t		bno,	/* starting block number of extent */
 	xfs_extlen_t		len,	/* length of extent */
 	struct xfs_owner_info	*oinfo,	/* extent owner */
-	enum xfs_ag_resv_type	type)	/* block reservation type */
+	enum xfs_ag_resv_type	type,	/* block reservation type */
+	bool			skip_discard)
 {
 	struct xfs_mount	*mp = tp->t_mountp;
 	struct xfs_buf		*agbp;
 	xfs_agnumber_t		agno = XFS_FSB_TO_AGNO(mp, bno);
 	xfs_agblock_t		agbno = XFS_FSB_TO_AGBNO(mp, bno);
 	int			error;
+	unsigned int		busy_flags = 0;
 
 	ASSERT(len != 0);
 	ASSERT(type != XFS_AG_RESV_AGFL);
@@ -2984,7 +3056,9 @@ xfs_free_extent(
 	if (error)
 		goto err;
 
-	xfs_extent_busy_insert(tp, agno, agbno, len, 0);
+	if (skip_discard)
+		busy_flags |= XFS_EXTENT_BUSY_SKIP_DISCARD;
+	xfs_extent_busy_insert(tp, agno, agbno, len, busy_flags);
 	return 0;
 
 err:
@@ -3049,55 +3123,6 @@ xfs_alloc_query_all(
 	return xfs_btree_query_all(cur, xfs_alloc_query_range_helper, &query);
 }
 
-/* Find the size of the AG, in blocks. */
-xfs_agblock_t
-xfs_ag_block_count(
-	struct xfs_mount	*mp,
-	xfs_agnumber_t		agno)
-{
-	ASSERT(agno < mp->m_sb.sb_agcount);
-
-	if (agno < mp->m_sb.sb_agcount - 1)
-		return mp->m_sb.sb_agblocks;
-	return mp->m_sb.sb_dblocks - (agno * mp->m_sb.sb_agblocks);
-}
-
-/*
- * Verify that an AG block number pointer neither points outside the AG
- * nor points at static metadata.
- */
-bool
-xfs_verify_agbno(
-	struct xfs_mount	*mp,
-	xfs_agnumber_t		agno,
-	xfs_agblock_t		agbno)
-{
-	xfs_agblock_t		eoag;
-
-	eoag = xfs_ag_block_count(mp, agno);
-	if (agbno >= eoag)
-		return false;
-	if (agbno <= XFS_AGFL_BLOCK(mp))
-		return false;
-	return true;
-}
-
-/*
- * Verify that an FS block number pointer neither points outside the
- * filesystem nor points at static AG metadata.
- */
-bool
-xfs_verify_fsbno(
-	struct xfs_mount	*mp,
-	xfs_fsblock_t		fsbno)
-{
-	xfs_agnumber_t		agno = XFS_FSB_TO_AGNO(mp, fsbno);
-
-	if (agno >= mp->m_sb.sb_agcount)
-		return false;
-	return xfs_verify_agbno(mp, agno, XFS_FSB_TO_AGBNO(mp, fsbno));
-}
-
 /* Is there a record covering a given extent? */
 int
 xfs_alloc_has_record(
@@ -3116,3 +3141,40 @@ xfs_alloc_has_record(
 
 	return xfs_btree_has_record(cur, &low, &high, exists);
 }
+
+/*
+ * Walk all the blocks in the AGFL.  The @walk_fn can return any negative
+ * error code or XFS_BTREE_QUERY_RANGE_ABORT.
+ */
+int
+xfs_agfl_walk(
+	struct xfs_mount	*mp,
+	struct xfs_agf		*agf,
+	struct xfs_buf		*agflbp,
+	xfs_agfl_walk_fn	walk_fn,
+	void			*priv)
+{
+	__be32			*agfl_bno;
+	unsigned int		i;
+	int			error;
+
+	agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agflbp);
+	i = be32_to_cpu(agf->agf_flfirst);
+
+	/* Nothing to walk in an empty AGFL. */
+	if (agf->agf_flcount == cpu_to_be32(0))
+		return 0;
+
+	/* Otherwise, walk from first to last, wrapping as needed. */
+	for (;;) {
+		error = walk_fn(mp, be32_to_cpu(agfl_bno[i]), priv);
+		if (error)
+			return error;
+		if (i == be32_to_cpu(agf->agf_fllast))
+			break;
+		if (++i == xfs_agfl_size(mp))
+			i = 0;
+	}
+
+	return 0;
+}