[PATCH 5.10 475/663] scsi: sd: sd_zbc: Dont pass GFP_NOIO to kvcalloc

From: Greg Kroah-Hartman
Date: Mon Mar 01 2021 - 18:14:01 EST


From: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>

[ Upstream commit 9acced3f58ad24407c1f9ebf53a8892c1e24cdb5 ]

Dan reported we're passing in GFP_NOIO to kvmalloc() which will then
fallback to doing kmalloc() instead of an optional vmalloc() if the size
exceeds kmalloc()s limits. This will break with drives that have zone
numbers exceeding PAGE_SIZE/sizeof(u32).

Instead of passing in GFP_NOIO, enter an implicit GFP_NOIO allocation
scope.

Link: https://lore.kernel.org/r/YCuvSfKw4qEQBr/t@mwanda
Link: https://lore.kernel.org/r/5a6345e2989fd06c049ac4e4627f6acb492c15b8.1613569821.git.johannes.thumshirn@xxxxxxx
Fixes: 5795eb443060: ("scsi: sd_zbc: emulate ZONE_APPEND commands")
Cc: Damien Le Moal <Damien.LeMoal@xxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/scsi/sd_zbc.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index cf07b7f935790..87a7274e4632b 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -688,6 +688,7 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
unsigned int nr_zones = sdkp->rev_nr_zones;
u32 max_append;
int ret = 0;
+ unsigned int flags;

/*
* For all zoned disks, initialize zone append emulation data if not
@@ -720,16 +721,19 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
disk->queue->nr_zones == nr_zones)
goto unlock;

+ flags = memalloc_noio_save();
sdkp->zone_blocks = zone_blocks;
sdkp->nr_zones = nr_zones;
- sdkp->rev_wp_offset = kvcalloc(nr_zones, sizeof(u32), GFP_NOIO);
+ sdkp->rev_wp_offset = kvcalloc(nr_zones, sizeof(u32), GFP_KERNEL);
if (!sdkp->rev_wp_offset) {
ret = -ENOMEM;
+ memalloc_noio_restore(flags);
goto unlock;
}

ret = blk_revalidate_disk_zones(disk, sd_zbc_revalidate_zones_cb);

+ memalloc_noio_restore(flags);
kvfree(sdkp->rev_wp_offset);
sdkp->rev_wp_offset = NULL;

--
2.27.0