The test gfp_flag & GFP_NOWAIT was always true, because both GFP_NOIO and
GFP_NOWAIT include the flag __GFP_KSWAPD_RECLAIM. Luckily, this oversight
didn't result in any harm; the loop always started with "try = 0".
This patch removes the faulty test and explicitly starts the loop with
"try = 0" (so that we don't hold the mutex in the first iteration).
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm.c | 19 +++++++++----------
1 file changed, 9 insertions(+), 10 deletions(-)
Index: linux-2.6/drivers/md/dm.c
===================================================================
--- linux-2.6.orig/drivers/md/dm.c 2025-01-08 17:24:52.000000000 +0100
+++ linux-2.6/drivers/md/dm.c 2025-01-08 17:26:52.000000000 +0100
@@ -1479,12 +1479,12 @@ static void setup_split_accounting(struc
static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci,
struct dm_target *ti, unsigned int num_bios,
- unsigned *len, gfp_t gfp_flag)
+ unsigned *len)
{
struct bio *bio;
- int try = (gfp_flag & GFP_NOWAIT) ? 0 : 1;
+ int try;
- for (; try < 2; try++) {
+ for (try = 0; try < 2; try++) {
int bio_nr;
if (try && num_bios > 1)
@@ -1508,8 +1508,7 @@ static void alloc_multiple_bios(struct b
}
static unsigned int __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti,
- unsigned int num_bios, unsigned int *len,
- gfp_t gfp_flag)
+ unsigned int num_bios, unsigned int *len)
{
struct bio_list blist = BIO_EMPTY_LIST;
struct bio *clone;
@@ -1526,7 +1525,7 @@ static unsigned int __send_duplicate_bio
* Using alloc_multiple_bios(), even if num_bios is 1, to consistently
* support allocating using GFP_NOWAIT with GFP_NOIO fallback.
*/
- alloc_multiple_bios(&blist, ci, ti, num_bios, len, gfp_flag);
+ alloc_multiple_bios(&blist, ci, ti, num_bios, len);
while ((clone = bio_list_pop(&blist))) {
if (num_bios > 1)
dm_tio_set_flag(clone_to_tio(clone), DM_TIO_IS_DUPLICATE_BIO);
@@ -1564,7 +1563,7 @@ static void __send_empty_flush(struct cl
atomic_add(ti->num_flush_bios, &ci->io->io_count);
bios = __send_duplicate_bios(ci, ti, ti->num_flush_bios,
- NULL, GFP_NOWAIT);
+ NULL);
atomic_sub(ti->num_flush_bios - bios, &ci->io->io_count);
}
} else {
@@ -1612,7 +1611,7 @@ static void __send_abnormal_io(struct cl
__max_io_len(ti, ci->sector, max_granularity, max_sectors));
atomic_add(num_bios, &ci->io->io_count);
- bios = __send_duplicate_bios(ci, ti, num_bios, &len, GFP_NOIO);
+ bios = __send_duplicate_bios(ci, ti, num_bios, &len);
/*
* alloc_io() takes one extra reference for submission, so the
* reference won't reach 0 without the following (+1) subtraction
@@ -1849,7 +1848,7 @@ static blk_status_t __send_zone_reset_al
* not go crazy with the clone allocation.
*/
alloc_multiple_bios(&blist, ci, ti, min(nr_reset, 32),
- NULL, GFP_NOIO);
+ NULL);
}
/* Get a clone and change it to a regular reset operation. */
@@ -1881,7 +1880,7 @@ static void __send_zone_reset_all_native
unsigned int bios;
atomic_add(1, &ci->io->io_count);
- bios = __send_duplicate_bios(ci, ti, 1, NULL, GFP_NOIO);
+ bios = __send_duplicate_bios(ci, ti, 1, NULL);
atomic_sub(1 - bios, &ci->io->io_count);
ci->sector_count = 0;
