[dm-devel] [PATCH] dm: fix dm_revalidate_zones() memory allocation
Damien Le Moal
damien.lemoal at wdc.com
Fri Jun 18 23:15:19 UTC 2021
Make sure that the zone write pointer offset array is allocated with a
vmalloc in dm_zone_revalidate_cb() by passing GFP_KERNEL gfp flag to
kvcalloc(). However, since we do not want to trigger IOs while
revalidating zones, change dm_revalidate_zones() to have the zone scan
done in GFP_NOIO context using memalloc_noio_save/restore calls.
Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
Fixes: bb37d77239af ("dm: introduce zone append emulation")
Signed-off-by: Damien Le Moal <damien.lemoal at wdc.com>
---
drivers/md/dm-zone.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/md/dm-zone.c b/drivers/md/dm-zone.c
index c2f26949f5ee..6d82a34438c8 100644
--- a/drivers/md/dm-zone.c
+++ b/drivers/md/dm-zone.c
@@ -205,7 +205,7 @@ static int dm_zone_revalidate_cb(struct blk_zone *zone, unsigned int idx,
if (!md->zwp_offset) {
md->zwp_offset =
kvcalloc(q->nr_zones, sizeof(unsigned int),
- GFP_NOIO);
+ GFP_KERNEL);
if (!md->zwp_offset)
return -ENOMEM;
}
@@ -230,6 +230,7 @@ static int dm_zone_revalidate_cb(struct blk_zone *zone, unsigned int idx,
static int dm_revalidate_zones(struct mapped_device *md, struct dm_table *t)
{
struct request_queue *q = md->queue;
+ unsigned int noio_flag;
int ret;
/*
@@ -241,9 +242,14 @@ static int dm_revalidate_zones(struct mapped_device *md, struct dm_table *t)
if (md->nr_zones)
return 0;
- /* Scan all zones to initialize everything */
+ /*
+ * Scan all zones to initialize everything. Ensure that all vmalloc
+ * operations in this context are done as if GFP_NOIO was specified.
+ */
+ noio_flag = memalloc_noio_save();
ret = dm_blk_do_report_zones(md, t, 0, q->nr_zones,
dm_zone_revalidate_cb, md);
+ memalloc_noio_restore(noio_flag);
if (ret < 0)
goto err;
if (ret != q->nr_zones) {
--
2.31.1
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