commit: 1e7de68c57daf75ec4b721f101f88cccf029e38c
From: Nicholas Bellinger <n...@linux-iscsi.org>
Date: Thu, 19 May 2011 20:19:10 -0700
Subject: [PATCH] [SCSI] target: Fix interrupt context bug with stats_lock and
core_tmr_alloc_req
This patch fixes two bugs wrt to the interrupt context usage of target
core with HW target mode drivers. It first converts the usage of struct
se_device->stats_lock in transport_get_lun_for_cmd() and core_tmr_lun_reset()
to properly use spin_lock_irq() to address an BUG with CONFIG_LOCKDEP_SUPPORT=y
enabled.
This patch also adds a 'in_interrupt()' check to allow GFP_ATOMIC usage from
core_tmr_alloc_req() to fix a 'sleeping in interrupt context' BUG with HW
target fabrics that require this logic to function.
Signed-off-by: Nicholas Bellinger <n...@linux-iscsi.org>
Cc: sta...@kernel.org
Signed-off-by: James Bottomley <jbottom...@parallels.com>
---
drivers/target/target_core_device.c | 4 ++--
drivers/target/target_core_tmr.c | 7 ++++---
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/target/target_core_device.c
b/drivers/target/target_core_device.c
index d25e208..fc10ed4 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -150,13 +150,13 @@ out:
{
struct se_device *dev = se_lun->lun_se_dev;
- spin_lock(&dev->stats_lock);
+ spin_lock_irq(&dev->stats_lock);
dev->num_cmds++;
if (se_cmd->data_direction == DMA_TO_DEVICE)
dev->write_bytes += se_cmd->data_length;
else if (se_cmd->data_direction == DMA_FROM_DEVICE)
dev->read_bytes += se_cmd->data_length;
- spin_unlock(&dev->stats_lock);
+ spin_unlock_irq(&dev->stats_lock);
}
/*
diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index 4a10983..59b8b9c 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -55,7 +55,8 @@ struct se_tmr_req *core_tmr_alloc_req(
{
struct se_tmr_req *tmr;
- tmr = kmem_cache_zalloc(se_tmr_req_cache, GFP_KERNEL);
+ tmr = kmem_cache_zalloc(se_tmr_req_cache, (in_interrupt()) ?
+ GFP_ATOMIC : GFP_KERNEL);
if (!(tmr)) {
printk(KERN_ERR "Unable to allocate struct se_tmr_req\n");
return ERR_PTR(-ENOMEM);
@@ -398,9 +399,9 @@ int core_tmr_lun_reset(
printk(KERN_INFO "LUN_RESET: SCSI-2 Released reservation\n");
}
- spin_lock(&dev->stats_lock);
+ spin_lock_irq(&dev->stats_lock);
dev->num_resets++;
- spin_unlock(&dev->stats_lock);
+ spin_unlock_irq(&dev->stats_lock);
DEBUG_LR("LUN_RESET: %s for [%s] Complete\n",
(preempt_and_abort_list) ? "Preempt" : "TMR",
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