No need for the commands_lock. The cmdr_lock is already held during
idr addition and deletion, so just grab it during traversal.
Note: This also fixes a issue where we should have been using at
least _bh locking in tcmu_handle_completions when taking the commands
lock to prevent the case where tcmu_handle_completions could be
interrupted by a timer softirq while the commands_lock is held.
Signed-off-by: Mike Christie <mchri...@redhat.com>
---
drivers/target/target_core_user.c | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)
diff --git a/drivers/target/target_core_user.c
b/drivers/target/target_core_user.c
index 7271ec2..5226b82 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -139,7 +139,6 @@ struct tcmu_dev {
struct radix_tree_root data_blocks;
struct idr commands;
- spinlock_t commands_lock;
struct timer_list timeout;
unsigned int cmd_time_out;
@@ -1012,10 +1011,7 @@ static unsigned int tcmu_handle_completions(struct
tcmu_dev *udev)
}
WARN_ON(tcmu_hdr_get_op(entry->hdr.len_op) != TCMU_OP_CMD);
- spin_lock(&udev->commands_lock);
cmd = idr_remove(&udev->commands, entry->hdr.cmd_id);
- spin_unlock(&udev->commands_lock);
-
if (!cmd) {
pr_err("cmd_id not found, ring is broken\n");
set_bit(TCMU_DEV_BIT_BROKEN, &udev->flags);
@@ -1113,7 +1109,6 @@ static struct se_device *tcmu_alloc_device(struct se_hba
*hba, const char *name)
INIT_LIST_HEAD(&udev->timedout_entry);
idr_init(&udev->commands);
- spin_lock_init(&udev->commands_lock);
setup_timer(&udev->timeout, tcmu_device_timedout,
(unsigned long)udev);
@@ -1332,16 +1327,14 @@ static void tcmu_dev_kref_release(struct kref *kref)
spin_unlock_bh(&timed_out_udevs_lock);
/* Upper layer should drain all requests before calling this */
- spin_lock_irq(&udev->commands_lock);
+ mutex_lock(&udev->cmdr_lock);
idr_for_each_entry(&udev->commands, cmd, i) {
if (tcmu_check_and_free_pending_cmd(cmd) != 0)
all_expired = false;
}
idr_destroy(&udev->commands);
- spin_unlock_irq(&udev->commands_lock);
WARN_ON(!all_expired);
- mutex_lock(&udev->cmdr_lock);
tcmu_blocks_release(&udev->data_blocks, 0, udev->dbi_max + 1);
mutex_unlock(&udev->cmdr_lock);
@@ -2058,9 +2051,9 @@ static void check_timedout_devices(void)
list_del_init(&udev->timedout_entry);
spin_unlock_bh(&timed_out_udevs_lock);
- spin_lock(&udev->commands_lock);
+ mutex_lock(&udev->cmdr_lock);
idr_for_each(&udev->commands, tcmu_check_expired_cmd, NULL);
- spin_unlock(&udev->commands_lock);
+ mutex_unlock(&udev->cmdr_lock);
spin_lock_bh(&timed_out_udevs_lock);
}
--
1.8.3.1
