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FAILED: patch "[PATCH] block: Limit zone array allocation size" failed to apply to 5.1-stable tree

PATCH [email protected] 2 participants 4 messages Jul 23, 2019 – Jul 25, 2019

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Stable branch Block layer Zoned block device (block layer)
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[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 5.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 26202928fafad8bda8b478edb7e62c885be623d7 Mon Sep 17 00:00:00 2001
From: Damien Le Moal <[email protected]>
Date: Mon, 1 Jul 2019 14:09:18 +0900
Subject: [PATCH] block: Limit zone array allocation size

Limit the size of the struct blk_zone array used in blk_revalidate_disk_zones() to avoid memory allocation failures leading to disk revalidation failure. Also further reduce the likelyhood of such failures by using kvcalloc() (that is vmalloc()) instead of allocating contiguous pages with alloc_pages().

Fixes 515ce6061312 ("scsi: sd_zbc: Fix sd_zbc_report_zones() buffer allocation")
Fixes e76239a3748c ("block: add a report_zones method")
Cc [email protected]
Reviewed-by Christoph Hellwig <[email protected]>
Reviewed-by Martin K. Petersen <[email protected]>
Signed-off-by Damien Le Moal <[email protected]>
Signed-off-by Jens Axboe <[email protected]>
block/blk-zoned.c +20 -16
index 58ced170b424..6c503824ba3f 100644
@@ -14,6 +14,8 @@
 #include <linux/rbtree.h>
 #include <linux/blkdev.h>
 #include <linux/blk-mq.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
 #include <linux/sched/mm.h>
 
 #include "blk.h"

@@ -371,22 +373,25 @@ static inline unsigned long *blk_alloc_zone_bitmap(int node,
  * Allocate an array of struct blk_zone to get nr_zones zone information.
  * The allocated array may be smaller than nr_zones.
  */
-static struct blk_zone *blk_alloc_zones(int node, unsigned int *nr_zones)
+static struct blk_zone *blk_alloc_zones(unsigned int *nr_zones)
 {
-	size_t size = *nr_zones * sizeof(struct blk_zone);
-	struct page *page;
-	int order;
-
-	for (order = get_order(size); order >= 0; order--) {
-		page = alloc_pages_node(node, GFP_NOIO | __GFP_ZERO, order);
-		if (page) {
-			*nr_zones = min_t(unsigned int, *nr_zones,
-				(PAGE_SIZE << order) / sizeof(struct blk_zone));
-			return page_address(page);
-		}
+	struct blk_zone *zones;
+	size_t nrz = min(*nr_zones, BLK_ZONED_REPORT_MAX_ZONES);
+
+	/*
+	 * GFP_KERNEL here is meaningless as the caller task context has
+	 * the PF_MEMALLOC_NOIO flag set in blk_revalidate_disk_zones()
+	 * with memalloc_noio_save().
+	 */
+	zones = kvcalloc(nrz, sizeof(struct blk_zone), GFP_KERNEL);
+	if (!zones) {
+		*nr_zones = 0;
+		return NULL;
 	}
 
-	return NULL;
+	*nr_zones = nrz;
+
+	return zones;
 }
 
 void blk_queue_free_zone_bitmaps(struct request_queue *q)

@@ -448,7 +453,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
 
 	/* Get zone information and initialize seq_zones_bitmap */
 	rep_nr_zones = nr_zones;
-	zones = blk_alloc_zones(q->node, &rep_nr_zones);
+	zones = blk_alloc_zones(&rep_nr_zones);
 	if (!zones)
 		goto out;
 

@@ -487,8 +492,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
 out:
 	memalloc_noio_restore(noio_flag);
 
-	free_pages((unsigned long)zones,
-		   get_order(rep_nr_zones * sizeof(struct blk_zone)));
+	kvfree(zones);
 	kfree(seq_zones_wlock);
 	kfree(seq_zones_bitmap);
include/linux/blkdev.h +5 -0
index 05036e3e3458..1ef375dafb1c 100644
@@ -344,6 +344,11 @@ struct queue_limits {
 
 #ifdef CONFIG_BLK_DEV_ZONED
 
+/*
+ * Maximum number of zones to report with a single report zones command.
+ */
+#define BLK_ZONED_REPORT_MAX_ZONES	8192U
+
 extern unsigned int blkdev_nr_zones(struct block_device *bdev);
 extern int blkdev_report_zones(struct block_device *bdev,
 			       sector_t sector, struct blk_zone *zones,
#1 lore raw
Quoted 8 lines · On Tue, 2019-07-23 at 13:56 +0200, [email protected] wrote:

The patch below does not apply to the 5.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

Greg,

I sent you a backported version that applies cleanly to both 5.1 and 5.2 stable trees.

Best regards.

Signature · 2 lines
Damien Le Moal
Western Digital Research
author maintainer
#2 lore raw
Quoted 6 lines · Damien Le Moal
Quoted 5 lines · On Tue, 2019-07-23 at 13:56 +0200, [email protected] wrote:

The patch below does not apply to the 5.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Quoted 8 lines
Quoted 3 lines

thanks,

greg k-h

Greg,

I sent you a backported version that applies cleanly to both 5.1 and 5.2 stable trees.

Please fix up your backports and send them in a format that I can use that does not lie about the author of the patch :)

thanks,

greg k-h

#3 lore raw
Quoted 16 lines · On Thu, 2019-07-25 at 08:34 +0200, [email protected] wrote:
Quoted 6 lines · Damien Le Moal
Quoted 5 lines · On Tue, 2019-07-23 at 13:56 +0200, [email protected] wrote:

The patch below does not apply to the 5.1-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

Quoted 8 lines
Quoted 3 lines

thanks,

greg k-h

Greg,

I sent you a backported version that applies cleanly to both 5.1 and 5.2 stable trees.

Quoted 6 lines

Please fix up your backports and send them in a format that I can use that does not lie about the author of the patch :)

thanks,

greg k-h

Ooops. Sorry about that. Fixing and resending.

Signature · 2 lines
Damien Le Moal
Western Digital Research