xfs: only call xf{array,blob}_destroy if we have a valid pointer

Only call the xfarray and xfblob destructor if we have a valid pointer,
and be sure to null out that pointer afterwards.  Note that this patch
fixes a large number of commits, most of which were merged between 6.9
and 6.10.

Cc: r772577952@gmail.com
Cc: <stable@vger.kernel.org> # v6.12
Fixes: ab97f4b ("xfs: repair AGI unlinked inode bucket lists")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Jiaming Zhang <r772577952@gmail.com>

Author: Darrick J. Wong

fs/xfs/scrub/agheader_repair.c

@@ -837,8 +837,12 @@ xrep_agi_buf_cleanup(
 {
 	struct xrep_agi	*ragi = buf;
 
-	xfarray_destroy(ragi->iunlink_prev);
-	xfarray_destroy(ragi->iunlink_next);
+	if (ragi->iunlink_prev)
+		xfarray_destroy(ragi->iunlink_prev);
+	ragi->iunlink_prev = NULL;
+	if (ragi->iunlink_next)
+		xfarray_destroy(ragi->iunlink_next);
+	ragi->iunlink_next = NULL;
 	xagino_bitmap_destroy(&ragi->iunlink_bmp);
 }
 

fs/xfs/scrub/attr_repair.c

@@ -1516,8 +1516,10 @@ xrep_xattr_teardown(
 		xfblob_destroy(rx->pptr_names);
 	if (rx->pptr_recs)
 		xfarray_destroy(rx->pptr_recs);
-	xfblob_destroy(rx->xattr_blobs);
-	xfarray_destroy(rx->xattr_records);
+	if (rx->xattr_blobs)
+		xfblob_destroy(rx->xattr_blobs);
+	if (rx->xattr_records)
+		xfarray_destroy(rx->xattr_records);
 	mutex_destroy(&rx->lock);
 	kfree(rx);
 }

fs/xfs/scrub/dir_repair.c

@@ -172,8 +172,12 @@ xrep_dir_teardown(
 	struct xrep_dir		*rd = sc->buf;
 
 	xrep_findparent_scan_teardown(&rd->pscan);
-	xfblob_destroy(rd->dir_names);
-	xfarray_destroy(rd->dir_entries);
+	if (rd->dir_names)
+		xfblob_destroy(rd->dir_names);
+	rd->dir_names = NULL;
+	if (rd->dir_entries)
+		xfarray_destroy(rd->dir_entries);
+	rd->dir_names = NULL;
 }
 
 /* Set up for a directory repair. */

fs/xfs/scrub/dirtree.c

@@ -81,8 +81,12 @@ xchk_dirtree_buf_cleanup(
 		kfree(path);
 	}
 
-	xfblob_destroy(dl->path_names);
-	xfarray_destroy(dl->path_steps);
+	if (dl->path_names)
+		xfblob_destroy(dl->path_names);
+	dl->path_names = NULL;
+	if (dl->path_steps)
+		xfarray_destroy(dl->path_steps);
+	dl->path_steps = NULL;
 	mutex_destroy(&dl->lock);
 }
 

fs/xfs/scrub/nlinks.c

@@ -971,7 +971,8 @@ xchk_nlinks_teardown_scan(
 
 	xfs_dir_hook_del(xnc->sc->mp, &xnc->dhook);
 
-	xfarray_destroy(xnc->nlinks);
+	if (xnc->nlinks)
+		xfarray_destroy(xnc->nlinks);
 	xnc->nlinks = NULL;
 
 	xchk_iscan_teardown(&xnc->collect_iscan);