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| author |   Nicholas Bellinger <nab@linux-iscsi.org> | 2013-06-06 01:35:18 -0700 |
|---|---|---|
| committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-06-20 14:10:39 -0700 |
| commit | 862e6389a78992d4ee44bf4f60051fe560470320 (patch) | |
| tree | 0b0cceedf17564748ca12e5b25d37ff1f9ac050f | |
| parent | target: Don't allocate pages for NULLIO devices (diff) | |
| download | linux-dev-862e6389a78992d4ee44bf4f60051fe560470320.tar.xz linux-dev-862e6389a78992d4ee44bf4f60051fe560470320.zip | |
target: Add transport_cmd_check_stop write_pending bit
This patch adds a new transport_cmd_check_stop() parameter for signaling
when TRANSPORT_WRITE_PENDING needs to be set.
This allows transport_generic_new_cmd() to avoid the extra lock acquire/release
of ->t_state_lock in the fast path for DMA_TO_DEVICE operations ahead of
transport_cmd_check_stop() + se_tfo->write_pending().
Cc: Christoph Hellwig <hch@lst.de>
Cc: Roland Dreier <roland@kernel.org>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Moussa Ba <moussaba@micron.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
| -rw-r--r-- | drivers/target/target_core_transport.c | 19 |
1 files changed, 9 insertions, 10 deletions
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c index 21e315874a54..39319efe50c1 100644 --- a/drivers/target/target_core_transport.c +++ b/drivers/target/target_core_transport.c @@ -446,11 +446,15 @@ static void target_remove_from_state_list(struct se_cmd *cmd) spin_unlock_irqrestore(&dev->execute_task_lock, flags); } -static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists) +static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists, + bool write_pending) { unsigned long flags; spin_lock_irqsave(&cmd->t_state_lock, flags); + if (write_pending) + cmd->t_state = TRANSPORT_WRITE_PENDING; + /* * Determine if IOCTL context caller in requesting the stopping of this * command for LUN shutdown purposes. @@ -515,7 +519,7 @@ static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists) static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd) { - return transport_cmd_check_stop(cmd, true); + return transport_cmd_check_stop(cmd, true, false); } static void transport_lun_remove_cmd(struct se_cmd *cmd) @@ -2116,12 +2120,7 @@ transport_generic_new_cmd(struct se_cmd *cmd) target_execute_cmd(cmd); return 0; } - - spin_lock_irq(&cmd->t_state_lock); - cmd->t_state = TRANSPORT_WRITE_PENDING; - spin_unlock_irq(&cmd->t_state_lock); - - transport_cmd_check_stop(cmd, false); + transport_cmd_check_stop(cmd, false, true); ret = cmd->se_tfo->write_pending(cmd); if (ret == -EAGAIN || ret == -ENOMEM) @@ -2319,7 +2318,7 @@ static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun) pr_debug("ConfigFS ITT[0x%08x] - CMD_T_STOP, skipping\n", cmd->se_tfo->get_task_tag(cmd)); spin_unlock_irqrestore(&cmd->t_state_lock, flags); - transport_cmd_check_stop(cmd, false); + transport_cmd_check_stop(cmd, false, false); return -EPERM; } cmd->transport_state |= CMD_T_LUN_FE_STOP; @@ -2427,7 +2426,7 @@ check_cond: spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags); - transport_cmd_check_stop(cmd, false); + transport_cmd_check_stop(cmd, false, false); complete(&cmd->transport_lun_fe_stop_comp); spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags); continue; |