libsas: Convert to host_lock less w/ interrupts disabled externally
Subsystems (2)
PATCH 4/11 libsas: Convert to host_lock less w/ interrupts disabled externally
From: Nicholas Bellinger <[email protected]>
This patch converts the libsas queuecommand to run in host_lock less mode w/ the new IRQ_DISABLE_SCSI_QCMD() that disables interrupts while calling ->queuecommand() dispatch.
--- drivers/scsi/libsas/sas_scsi_host.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)
drivers/scsi/libsas/sas_scsi_host.c +2 -2
@@ -189,7 +189,7 @@ int sas_queue_up(struct sas_task *task)* Note: XXX: Remove the host unlock/lock pair when SCSI Core can * call us without holding an IRQ spinlock... */ -static int sas_queuecommand_lck(struct scsi_cmnd *cmd, +static int sas_queuecommand_irq_disable(struct scsi_cmnd *cmd, void (*scsi_done)(struct scsi_cmnd *)) __releases(host->host_lock) __acquires(dev->sata_dev.ap->lock)
@@ -254,7 +254,7 @@ out:return res; } -DEF_SCSI_QCMD (sas_queuecommand) +IRQ_DISABLE_SCSI_QCMD (sas_queuecommand) static void sas_eh_finish_cmd(struct scsi_cmnd *cmd) {
Signature · 1 line
1.7.2.3
drivers/scsi/libsas/sas_scsi_host.c int sas_queue_up(struct sas_task *task) · line 190
Quoted 3 lines
drivers/scsi/libsas/sas_scsi_host.c +0
-0@@ -189,7 +189,7 @@ int sas_queue_up(struct sas_task *task)* Note: XXX: Remove the host unlock/lock pair when SCSI Core can * call us without holding an IRQ spinlock...
That comment can be removed now.
drivers/scsi/libsas/sas_scsi_host.c int sas_queue_up(struct sas_task *task) · line 192
Quoted 2 lines
drivers/scsi/libsas/sas_scsi_host.c +0
-1*/ -static int sas_queuecommand_lck(struct scsi_cmnd *cmd,
That's now how the code looks like upstream.
drivers/scsi/libsas/sas_scsi_host.c int sas_queue_up(struct sas_task *task) · line 195
Quoted 4 lines
drivers/scsi/libsas/sas_scsi_host.c +1
-0+static int sas_queuecommand_irq_disable(struct scsi_cmnd *cmd, void (*scsi_done)(struct scsi_cmnd *)) __releases(host->host_lock) __acquires(dev->sata_dev.ap->lock)
The host_lock annotations are not incorrect, and the sata_dev ones never made sense.
drivers/scsi/libsas/sas_scsi_host.c out: · line 257
Quoted 6 lines
drivers/scsi/libsas/sas_scsi_host.c +1
-1@@ -254,7 +254,7 @@ out:return res; } -DEF_SCSI_QCMD (sas_queuecommand) +IRQ_DISABLE_SCSI_QCMD (sas_queuecommand)
And in addition this doesn't even seem correct to me. First thing sas_queuecommand upstream does is spin_unlock_irq on the host_lock which it expects to be held, then it does a spin_lock_irqsave for the sata case, or operations that do not appear to need a lock for the sas case.
Quoted 23 lines · Christoph Hellwig
Review int sas_queue_up(struct sas_task *task) · line 190
Quoted 3 lines
(quoted diff) +0
-0@@ -189,7 +189,7 @@ int sas_queue_up(struct sas_task *task) * Note: XXX: Remove the host unlock/lock pair when SCSI Core can * call us without holding an IRQ spinlock...That comment can be removed now.
Review int sas_queue_up(struct sas_task *task) · line 192
Quoted 2 lines
(quoted diff) +0
-1*/ -static int sas_queuecommand_lck(struct scsi_cmnd *cmd,That's now how the code looks like upstream.
Review int sas_queue_up(struct sas_task *task) · line 195
Quoted 4 lines
(quoted diff) +1
-0+static int sas_queuecommand_irq_disable(struct scsi_cmnd *cmd, void (*scsi_done)(struct scsi_cmnd *)) __releases(host->host_lock) __acquires(dev->sata_dev.ap->lock)The
host_lockannotations are not incorrect, and thesata_devones never made sense.Quoted 4 lines
(quoted diff) +0
-0@@ -254,7 +254,7 @@ out: return res; }
Quoted 8 lines
Review out: · line 257
Quoted 2 lines
(quoted diff) +1
-1-DEF_SCSI_QCMD(sas_queuecommand) +IRQ_DISABLE_SCSI_QCMD(sas_queuecommand)And in addition this doesn't even seem correct to me. First thing
sas_queuecommandupstream does isspin_unlock_irqon thehost_lockwhich it expects to be held, then it does aspin_lock_irqsavefor the sata case, or operations that do not appear to need a lock for the sas case.
Ugh, this was the one patch that I carried forwad and had to apply by hand, and evidently I missed the some bits. Pushing this commit now..
Thanks,
Quoted 1 line
From
444d87126389286c869d10c947707c1d33855995Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <[email protected]>
Date: Wed, 17 Nov 2010 22:38:23 +0000
Subject: [PATCH] libsas: Added dropped bits for host_lock-less operation
This patch fixes drop-lock_less usage, lockdep annotation, and comment changes that where dropped while moving the libsas forward.
--- drivers/scsi/libsas/sas_scsi_host.c | 8 -------- 1 files changed, 0 insertions(+), 8 deletions(-)
(quoted diff) +0 -0
b/drivers/scsi/libsas/sas_scsi_host.c
index 595ed21..011580f 100644
drivers/scsi/libsas/sas_scsi_host.c +0 -7
@@ -185,24 +185,17 @@ int sas_queue_up(struct sas_task *task)/** * sas_queuecommand -- Enqueue a command for processing * @parameters: See SCSI Core documentation -* -* Note: XXX: Remove the host unlock/lock pair when SCSI Core can -* call us without holding an IRQ spinlock... */ static int sas_queuecommand_irq_disable (struct scsi_cmnd *cmd,void (*scsi_done)(struct scsi_cmnd *)) - __releases(host->host_lock) __acquires(dev->sata_dev.ap->lock) __releases(dev->sata_dev.ap->lock) - __acquires(host->host_lock) {int res =0 ;struct domain_device *dev =cmd_to_domain_dev (cmd);struct Scsi_Host *host = cmd->device->host;struct sas_internal *i =to_sas_internal (host->transportt); -spin_unlock_irq (host->host_lock); - {struct sas_ha_struct *sas_ha = dev->port->ha;struct sas_task *task;
@@ -250,7 +243,6 @@ static int sas_queuecommand_irq_disable(struct
scsi_cmnd *cmd,
}
}
out:
- spin_lock_irq(host->host_lock);
return res;}
Signature · 1 line
1.7.2.3
Quoted 5 lines
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