Especially when using tcmu with tcm_loop, memory allocations with GFP_KERNEL for a LUN can cause write back to the same LUN. So we have to use GFP_NOIO when allocation is done while handling commands or while holding cmdr_lock. Signed-off-by: Bodo Stroesser <bostroesser@xxxxxxxxx> --- This patch is based on Martin's for-next branch plus my short series "scsi: target: tcmu: Replace IDR and radix_tree with XArray" See: https://lore.kernel.org/linux-scsi/20210224185335.13844-1-bostroesser@xxxxxxxxx/ drivers/target/target_core_user.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index ada3ef982969..9e1b115cb032 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -518,7 +518,7 @@ static inline int tcmu_get_empty_block(struct tcmu_dev *udev, if (!page) goto err_alloc; - if (xa_store(&udev->data_blocks, dbi, page, GFP_KERNEL)) + if (xa_store(&udev->data_blocks, dbi, page, GFP_NOIO)) goto err_insert; } @@ -1272,7 +1272,7 @@ tcmu_tmr_notify(struct se_device *se_dev, enum tcm_tmreq_table tmf, pr_debug("TMR event %d on dev %s, aborted cmds %d, afflicted cmd_ids %d\n", tcmu_tmr_type(tmf), udev->name, i, cmd_cnt); - tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_KERNEL); + tmr = kmalloc(sizeof(*tmr) + cmd_cnt * sizeof(*cmd_ids), GFP_NOIO); if (!tmr) goto unlock; -- 2.12.3
