[PATCH] scsi: vmw-pvscsi: return DID_BUS_BUSY for adapter-initated aborts

[Jim Gill]

The vmw_pvscsi driver returns DID_ABORT for commands aborted internally
by the adapter, leading to the filesystem going read-only. Change the
result to DID_BUS_BUSY, causing the kernel to retry the command.

Signed-off-by: Jim Gill 
---
 drivers/scsi/vmw_pvscsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/vmw_pvscsi.c b/drivers/scsi/vmw_pvscsi.c
index c374e3b..777e5f1 100644
--- a/drivers/scsi/vmw_pvscsi.c
+++ b/drivers/scsi/vmw_pvscsi.c
@@ -609,7 +609,7 @@ static void pvscsi_complete_request(struct pvscsi_adapter 
*adapter,
break;
 
case BTSTAT_ABORTQUEUE:
-   cmd->result = (DID_ABORT << 16);
+   cmd->result = (DID_BUS_BUSY << 16);
break;
 
case BTSTAT_SCSIPARITY:
-- 
2.7.4

[PATCH] scsi: vmw-pvscsi: return DID_BUS_BUSY for adapter-initated aborts

[Jim Gill]

The vmw_pvscsi driver returns DID_ABORT for commands aborted internally
by the adapter, leading to the filesystem going read-only. Change the
result to DID_BUS_BUSY, causing the kernel to retry the command.

Signed-off-by: Jim Gill 
---
 drivers/scsi/vmw_pvscsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/vmw_pvscsi.c b/drivers/scsi/vmw_pvscsi.c
index c374e3b..777e5f1 100644
--- a/drivers/scsi/vmw_pvscsi.c
+++ b/drivers/scsi/vmw_pvscsi.c
@@ -609,7 +609,7 @@ static void pvscsi_complete_request(struct pvscsi_adapter 
*adapter,
break;
 
case BTSTAT_ABORTQUEUE:
-   cmd->result = (DID_ABORT << 16);
+   cmd->result = (DID_BUS_BUSY << 16);
break;
 
case BTSTAT_SCSIPARITY:
-- 
2.7.4

Re: [VERY EARLY RFC 00/13] Rework SCSI results handling

[Martin K. Petersen]

Johannes,

> here's a early preview of my SCSI results rework so we can eventually
> discuss things next week at LSF/MM (it still has compiler errors on
> aic7xxx and scsi_debug).

Here's what I'd like to see:

 - Forget about cramming everything into that dreaded u32 result. Bart's
   suggestion of making it a union is fine but it's perpetuating that
   these fields are one thing. And they really aren't.

   I'd rather not be confined to the crusty old model throughout
   SCSI. We can synthesize the u32 result the few places where it's
   actually required (i.e. returned to userland).

 - Create separate scsi_cmnd status fields for host, driver, target
   (SAM), and transport (msg). And maybe block layer errno as suggested.

 - Fix the naming so it makes sense. No more DID_SPOT_RUN. Let's have
   HOST_FOO / DRIVER_BAR / SAM_STAT_BAZ so it's clear who said what.

 - For the first iteration, maybe we can keep the message goo. But
   ideally I'd like to see the SPI-specifics moved to the SPI transport
   class. And then have an opaque transport error field in the scsi_cmnd
   that other transports can use as well.

 - If the interface naming is sensible, I don't think we need wrappers.
   But if it helps the driver conversion, I don't have a problem having
   them as long as they are self-documenting:

   scsi_set_command_status(HOST_FOO, DRIVER_SENSE, SAM_STAT_BAZ);

   is infinitely less error prone than:

   result = (NON_SENSE << 24) | (DID_RUN << 16) | (SPOT_FORGOT_TO_SHIFT);

I'll set aside a slot next week...

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: [PATCH] [v2] scsi: ips: fix firmware timestamps for 32-bit

[Martin K. Petersen]

Arnd,

> do_gettimeofday() is deprecated since it will stop working in 2038 on
> 32-bit platforms, leading to incorrect times passed to the firmware.
> On 64-bit platforms the current code appears to be fine, as the
> calculation passes an 8-bit century number into the firmware that can
> represent times long in the future (possibly until 25599).
>
> Using ktime_get_real_seconds() to get a 64-bit seconds value and
> time64_to_tm() to convert it into the firmware format greatly
> simplifies the ips timekeeping code, makes 32-bit and 64-bit behave
> the same way here, and gets us closer to removing the deprecated
> interfaces.

Applied to 4.18/scsi-queue, thanks!

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: [PATCH] [RESEND 2] scsi: esas2r: use ktime_get_real_seconds()

[Martin K. Petersen]

Arnd,

> do_gettimeofday() is deprecated because of the y2038 overflow.  Here,
> we use the result to pass into a 32-bit field in the firmware, which
> still risks an overflow, but if the firmware is written to expect
> unsigned values, it can at least last until y2106, and there is not
> much we can do about it.
>
> This changes do_gettimeofday() to ktime_get_real_seconds(), which at
> least simplifies the code a bit, and avoids the deprecated
> interface. I'm adding a comment about the overflow to document what
> happens.

Applied to 4.18/scsi-queue. Thanks!

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: [PATCH scsi-next] scsi: mvumi: Using module_pci_driver.

[Martin K. Petersen]

YueHaibing,

> Remove boilerplate code by using macro module_pci_driver.

Applied to 4.18/scsi-queue. Thank you!

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: [PATCH][V2] isci: Fix infinite loop in while loop

[Martin K. Petersen]

Colin,

> In the case when the phy_mask is bitwise anded with the phy_index bit
> is zero the continue statement currently jumps to the next iteration
> of the while loop and phy_index is never actually incremented,
> potentially causing an infinite loop if phy_index is less than
> SCI_MAX_PHS. Fix this by turning the while loop into a for loop.

Applied to 4.17/scsi-fixes. Thanks!

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: [PATCH v3 0/6] scsi: handle special return codes for ABORTED COMMAND

[Martin K. Petersen]

Martin,

> Here is another attempt to handle the special return codes for ABORTED
> COMMAND for certain SCSI devices. Following MKP's recommendation, I've
> created two new BLIST flags, simplifying the code in scsi_error.c
> compared to the previous versions. Rather than using "free" bits, I
> increased the length of blist_flag_t to 64 bit, and used previously
> unused bits. I also added checking for obsolete and unused bits.
>
> For the blist_flag_t size increase, I used sparse to try and avoid
> regressions; that necessitated fixing sparse's errors for the current
> code first.

Much better, thanks for reworking this. Applied to 4.18/scsi-queue.

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: [PATCH v2] target: Fix Fortify_panic kernel exception

[Martin K. Petersen]

Bryant,

> The bug exists in the memcmp in which the length passed in must be
> guaranteed to be 1. This bug currently exists because the second
> pointer passed in, can be smaller than the cmd->data_length, which
> causes a fortify_panic.
>
> The fix is to use memchr_inv instead to find whether or not a 0 exists
> instead of using memcmp. This way you dont have to worry about buffer
> overflow which is the reason for the fortify_panic.

Clarified the commit description a bit and applied the patch
4.17/scsi-fixes. Thanks!

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: target: clean up kernel-doc and add driver-api document

[Martin K. Petersen]

Randy,

> This patch series fixes kernel-doc warnings in drivers/target/ and its
> header files, then adds a Documentation driver-api chapter for target
> driver interfaces.

Applied to 4.18/scsi-queue. Thanks!

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: Representative Needed.

[PPMC OFFSHORE]

Good day,

  I am seeking your concept with great gratitude to present you as a 
representative to carry out business transactions with a reasonable share upon 
your interest and cooperation to work with us in trust. If interested please 
get back.

Regards
Kingsley

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

Re: [PATCH] bsg referencing bus driver module

[Anatoliy Glagolev]

 
> This patch isn't applyable because your mailer has changed all the tabs
> to spaces.
> 
> I also think there's no need to do it this way.  I think what we need
> is for fc_bsg_remove() to wait until the bsg queue is drained.  It does
> look like the author thought this happened otherwise the code wouldn't
> have the note.  If we fix it that way we can do the same thing in all
> the other transport classes that use bsg (which all have a similar
> issue).
> 
> James
> 

Thanks, James. Sorry about the tabs; re-sending.

On fc_bsg_remove()...: are you suggesting to implement the whole fix
in scsi_transport_fc.c? That would be nice, but I do not see how that
is possible. Even with the queue drained bsg still holds a reference
to the Scsi_Host via bsg_class_device; bsg_class_device itself is
referenced on bsg_open and kept around while a user-mode process keeps
a handle to bsg.
Even if we somehow implement the waiting the call may be stuck
forever if the user-mode process keeps the handle.
I think handling it via a rererence to the module is more consistent
with the way things are done in Linux. You suggested the approach
youself back in "Waiting for scsi_host_template release" discussion.


>From df939b80d02bf37b21efaaef8ede86cfd39b0cb8 Mon Sep 17 00:00:00 2001
From: Anatoliy Glagolev 
Date: Thu, 19 Apr 2018 15:06:06 -0600
Subject: [PATCH] bsg referencing parent module

Fixing a bug when bsg layer holds the last reference to device
when the device's module has been unloaded. Upon dropping the
reference the device's release function may touch memory of
the unloaded module.
---
 block/bsg-lib.c  | 24 ++--
 block/bsg.c  | 29 ++---
 drivers/scsi/scsi_transport_fc.c |  8 ++--
 include/linux/bsg-lib.h  |  4 
 include/linux/bsg.h  |  5 +
 5 files changed, 63 insertions(+), 7 deletions(-)

diff --git a/block/bsg-lib.c b/block/bsg-lib.c
index fc2e5ff..90c28fd 100644
--- a/block/bsg-lib.c
+++ b/block/bsg-lib.c
@@ -309,6 +309,25 @@ struct request_queue *bsg_setup_queue(struct device *dev, 
const char *name,
bsg_job_fn *job_fn, int dd_job_size,
void (*release)(struct device *))
 {
+   return bsg_setup_queue_ex(dev, name, job_fn, dd_job_size, release,
+   NULL);
+}
+EXPORT_SYMBOL_GPL(bsg_setup_queue);
+
+/**
+ * bsg_setup_queue - Create and add the bsg hooks so we can receive requests
+ * @dev: device to attach bsg device to
+ * @name: device to give bsg device
+ * @job_fn: bsg job handler
+ * @dd_job_size: size of LLD data needed for each job
+ * @release: @dev release function
+ * @dev_module: @dev's module
+ */
+struct request_queue *bsg_setup_queue_ex(struct device *dev, const char *name,
+   bsg_job_fn *job_fn, int dd_job_size,
+   void (*release)(struct device *),
+   struct module *dev_module)
+{
struct request_queue *q;
int ret;
 
@@ -331,7 +350,8 @@ struct request_queue *bsg_setup_queue(struct device *dev, 
const char *name,
blk_queue_softirq_done(q, bsg_softirq_done);
blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
 
-   ret = bsg_register_queue(q, dev, name, _transport_ops, release);
+   ret = bsg_register_queue_ex(q, dev, name, _transport_ops, release,
+   dev_module);
if (ret) {
printk(KERN_ERR "%s: bsg interface failed to "
   "initialize - register queue\n", dev->kobj.name);
@@ -343,4 +363,4 @@ struct request_queue *bsg_setup_queue(struct device *dev, 
const char *name,
blk_cleanup_queue(q);
return ERR_PTR(ret);
 }
-EXPORT_SYMBOL_GPL(bsg_setup_queue);
+EXPORT_SYMBOL_GPL(bsg_setup_queue_ex);
diff --git a/block/bsg.c b/block/bsg.c
index defa06c..6920c5b 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -750,7 +750,8 @@ static struct bsg_device *__bsg_get_device(int minor, 
struct request_queue *q)
return bd;
 }
 
-static struct bsg_device *bsg_get_device(struct inode *inode, struct file 
*file)
+static struct bsg_device *bsg_get_device(struct inode *inode, struct file 
*file,
+   struct bsg_class_device **pbcd)
 {
struct bsg_device *bd;
struct bsg_class_device *bcd;
@@ -766,6 +767,7 @@ static struct bsg_device *bsg_get_device(struct inode 
*inode, struct file *file)
 
if (!bcd)
return ERR_PTR(-ENODEV);
+   *pbcd = bcd;
 
bd = __bsg_get_device(iminor(inode), bcd->queue);
if (bd)
@@ -781,22 +783,34 @@ static struct bsg_device *bsg_get_device(struct inode 
*inode, struct file *file)
 static int bsg_open(struct inode *inode, struct file *file)
 {
struct bsg_device *bd;
+   struct bsg_class_device *bcd;
 
-   bd = bsg_get_device(inode, file);
+   bd = bsg_get_device(inode, file, );
 
if (IS_ERR(bd))
return PTR_ERR(bd);
 
file->private_data = bd;
+   if 

Re: [PATCH 1/2] scsi: st: Replace GFP_ATOMIC with GFP_KERNEL in st_probe

[Martin K. Petersen]

Jia-Ju,

> st_probe() is never called in atomic context.

Applied patches 1 and 2 to 4.18/scsi-queue. Thanks!

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: [PATCH v2 01/14] mpt3sas: Bug fix for big endian systems.

[Martin K. Petersen]

Chaitra,

A few comments:

> @@ -426,7 +427,7 @@ static void _clone_sg_entries(struct MPT3SAS_ADAPTER *ioc,
>   dst_addr_phys = _base_get_chain_phys(ioc,
>   smid, sge_chain_count);
>   WARN_ON(dst_addr_phys > U32_MAX);
> - sgel->Address = (u32)dst_addr_phys;
> + sgel->Address = cpu_to_le32((u32)dst_addr_phys);

I tend to prefer lower_32_bits() but that's your choice.

> @@ -3040,8 +3047,9 @@ mpt3sas_base_map_resources(struct MPT3SAS_ADAPTER *ioc)
>   }
>  
>   for (i = 0; i < ioc->combined_reply_index_count; i++) {
> - ioc->replyPostRegisterIndex[i] = (resource_size_t *)
> -  ((u8 *)>chip->Doorbell +
> + ioc->replyPostRegisterIndex[i] =
> + (volatile void __iomem *)
> +  ((u8 __force *)>chip->Doorbell +
>MPI25_SUP_REPLY_POST_HOST_INDEX_OFFSET +
>(i * MPT3_SUP_REPLY_POST_HOST_INDEX_REG_OFFSET));

Do you really need volatile here? The existing resource_size_t didn't
imply volatile.

Why the double type casts? You've already changed replyPostRegisterIndex
to be 'volatile void __iomem **' in the header file. So why not:

ioc->replyPostRegisterIndex[i] =
>chip->Doorbell +
MPI25_SUP_REPLY_POST_HOST_INDEX_OFFSET +
i * MPT3_SUP_REPLY_POST_HOST_INDEX_REG_OFFSET;

Also looks like ioc->reply_post_host_index handling a few lines further
down could lose the type casts.

> @@ -3386,7 +3394,7 @@ _base_put_smid_mpi_ep_scsi_io(struct MPT3SAS_ADAPTER 
> *ioc, u16 smid, u16 handle)
>   __le32 *mfp = (__le32 *)mpt3sas_base_get_msg_frame(ioc, smid);
>  
>   _clone_sg_entries(ioc, (void *) mfp, smid);
> - mpi_req_iomem = (void *)ioc->chip +
> + mpi_req_iomem = (void __force *)ioc->chip +
>   MPI_FRAME_START_OFFSET + (smid * ioc->request_sz);
>   _base_clone_mpi_to_sys_mem(mpi_req_iomem, (void *)mfp,
>   ioc->request_sz);

Wouldn't it be better to add __iomem to the definition of mpi_req_iomem?

> + nvme_encap_request->ErrorResponseBaseAddress =
> + cpu_to_le64(ioc->sense_dma & 0xUL);

upper_32_bits()?

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: usercopy whitelist woe in scsi_sense_cache

[Oleksandr Natalenko]

Hi.

On 20.04.2018 22:23, Kees Cook wrote:

I don't know the "how", I only found the "what". :) If you want, grab
the reproducer VM linked to earlier in this thread; it'll hit the
problem within about 30 seconds of running the reproducer.


Just to avoid a possible confusion I should note that I've removed the 
reproducer from my server, but I can re-upload it if needed.


--
  Oleksandr Natalenko (post-factum)

Re: usercopy whitelist woe in scsi_sense_cache

[Kees Cook]

On Thu, Apr 19, 2018 at 2:32 AM, Paolo Valente  wrote:
> I'm missing something here.  When the request gets completed in the
> first place, the hook bfq_finish_requeue_request gets called, and that
> hook clears both ->elv.priv elements (as the request has a non-null
> elv.icq).  So, when bfq gets the same request again, those elements
> must be NULL.  What am I getting wrong?
>
> I have some more concern on this point, but I'll stick to this for the
> moment, to not create more confusion.

I don't know the "how", I only found the "what". :) If you want, grab
the reproducer VM linked to earlier in this thread; it'll hit the
problem within about 30 seconds of running the reproducer.

-Kees

-- 
Kees Cook
Pixel Security

Re: [Patch v2] Storvsc: Select channel based on available percentage of ring buffer to write

[Martin K. Petersen]

Long,

> This is a best effort for estimating on how busy the ring buffer is
> for that channel, based on available buffer to write in percentage. It
> is still possible that at the time of actual ring buffer write, the
> space may not be available due to other processes may be writing at
> the time.
>
> Selecting a channel based on how full it is can reduce the possibility
> that a ring buffer write will fail, and avoid the situation a channel
> is over busy.
>
> Now it's possible that storvsc can use a smaller ring buffer size
> (e.g. 40k bytes) to take advantage of cache locality.

Applied to 4.18/scsi-queue. Thank you!

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: [PATCH v2] storvsc: Set up correct queue depth values for IDE devices

[Martin K. Petersen]

Long,

> If num_cpus=1, we don't have any sub channels.
>
> The host offers one sub channel for VM with 5 CPUs, after that it offers
> an additional sub channel every 4 CPUs.
>
> The primary channel is always offered.

Applied to 4.17/scsi-fixes. Thanks!

-- 
Martin K. Petersen  Oracle Linux Engineering

[PATCH] [v2] scsi: ips: fix firmware timestamps for 32-bit

[Arnd Bergmann]

do_gettimeofday() is deprecated since it will stop working in 2038 on
32-bit platforms, leading to incorrect times passed to the firmware.
On 64-bit platforms the current code appears to be fine, as the
calculation passes an 8-bit century number into the firmware that can
represent times long in the future (possibly until 25599).

Using ktime_get_real_seconds() to get a 64-bit seconds value and
time64_to_tm() to convert it into the firmware format greatly simplifies
the ips timekeeping code, makes 32-bit and 64-bit behave the same way
here, and gets us closer to removing the deprecated interfaces.

Signed-off-by: Arnd Bergmann 
---
v2: addressed review comments from Finn Thain:
  - rewrite changelog text
  - drop now-unused macros
  - fix incorrect century calculation
---
 drivers/scsi/ips.c | 78 +++---
 drivers/scsi/ips.h | 11 +---
 2 files changed, 17 insertions(+), 72 deletions(-)

diff --git a/drivers/scsi/ips.c b/drivers/scsi/ips.c
index a70f36a6d205..0e8a22c38c11 100644
--- a/drivers/scsi/ips.c
+++ b/drivers/scsi/ips.c
@@ -291,7 +291,7 @@ static void ips_freescb(ips_ha_t *, ips_scb_t *);
 static void ips_setup_funclist(ips_ha_t *);
 static void ips_statinit(ips_ha_t *);
 static void ips_statinit_memio(ips_ha_t *);
-static void ips_fix_ffdc_time(ips_ha_t *, ips_scb_t *, time_t);
+static void ips_fix_ffdc_time(ips_ha_t *, ips_scb_t *, time64_t);
 static void ips_ffdc_reset(ips_ha_t *, int);
 static void ips_ffdc_time(ips_ha_t *);
 static uint32_t ips_statupd_copperhead(ips_ha_t *);
@@ -985,10 +985,7 @@ static int __ips_eh_reset(struct scsi_cmnd *SC)
 
/* FFDC */
if (le32_to_cpu(ha->subsys->param[3]) & 0x30) {
-   struct timeval tv;
-
-   do_gettimeofday();
-   ha->last_ffdc = tv.tv_sec;
+   ha->last_ffdc = ktime_get_real_seconds();
ha->reset_count++;
ips_ffdc_reset(ha, IPS_INTR_IORL);
}
@@ -2392,7 +2389,6 @@ static int
 ips_hainit(ips_ha_t * ha)
 {
int i;
-   struct timeval tv;
 
METHOD_TRACE("ips_hainit", 1);
 
@@ -2407,8 +2403,7 @@ ips_hainit(ips_ha_t * ha)
 
/* Send FFDC */
ha->reset_count = 1;
-   do_gettimeofday();
-   ha->last_ffdc = tv.tv_sec;
+   ha->last_ffdc = ktime_get_real_seconds();
ips_ffdc_reset(ha, IPS_INTR_IORL);
 
if (!ips_read_config(ha, IPS_INTR_IORL)) {
@@ -2548,12 +2543,9 @@ ips_next(ips_ha_t * ha, int intr)
 
if ((ha->subsys->param[3] & 0x30)
&& (ha->scb_activelist.count == 0)) {
-   struct timeval tv;
-
-   do_gettimeofday();
-
-   if (tv.tv_sec - ha->last_ffdc > IPS_SECS_8HOURS) {
-   ha->last_ffdc = tv.tv_sec;
+   time64_t now = ktime_get_real_seconds();
+   if (now - ha->last_ffdc > IPS_SECS_8HOURS) {
+   ha->last_ffdc = now;
ips_ffdc_time(ha);
}
}
@@ -5988,59 +5980,21 @@ ips_ffdc_time(ips_ha_t * ha)
 /*  */
 //
 static void
-ips_fix_ffdc_time(ips_ha_t * ha, ips_scb_t * scb, time_t current_time)
+ips_fix_ffdc_time(ips_ha_t * ha, ips_scb_t * scb, time64_t current_time)
 {
-   long days;
-   long rem;
-   int i;
-   int year;
-   int yleap;
-   int year_lengths[2] = { IPS_DAYS_NORMAL_YEAR, IPS_DAYS_LEAP_YEAR };
-   int month_lengths[12][2] = { {31, 31},
-   {28, 29},
-   {31, 31},
-   {30, 30},
-   {31, 31},
-   {30, 30},
-   {31, 31},
-   {31, 31},
-   {30, 30},
-   {31, 31},
-   {30, 30},
-   {31, 31}
-   };
+   struct tm tm;
 
METHOD_TRACE("ips_fix_ffdc_time", 1);
 
-   days = current_time / IPS_SECS_DAY;
-   rem = current_time % IPS_SECS_DAY;
-
-   scb->cmd.ffdc.hour = (rem / IPS_SECS_HOUR);
-   rem = rem % IPS_SECS_HOUR;
-   scb->cmd.ffdc.minute = (rem / IPS_SECS_MIN);
-   scb->cmd.ffdc.second = (rem % IPS_SECS_MIN);
-
-   year = IPS_EPOCH_YEAR;
-   while (days < 0 || days >= year_lengths[yleap = 
IPS_IS_LEAP_YEAR(year)]) {
-   int newy;
-
-   newy = year + (days / IPS_DAYS_NORMAL_YEAR);
-   if (days < 0)
-   --newy;
-   days -= (newy - year) * IPS_DAYS_NORMAL_YEAR +
-   IPS_NUM_LEAP_YEARS_THROUGH(newy - 1) -
-   IPS_NUM_LEAP_YEARS_THROUGH(year - 1);
-   year = newy;
-   }
-
-   scb->cmd.ffdc.yearH = year / 100;
-   scb->cmd.ffdc.yearL = year % 100;
-
-   for (i = 0; days >= month_lengths[i][yleap]; ++i)
-   days -= month_lengths[i][yleap];
+   time64_to_tm(current_time, 0, );
 
-   scb->cmd.ffdc.month = i + 1;
-   scb->cmd.ffdc.day = days + 1;
+   

[PATCH] [RESEND 2] scsi: esas2r: use ktime_get_real_seconds()

[Arnd Bergmann]

do_gettimeofday() is deprecated because of the y2038 overflow.
Here, we use the result to pass into a 32-bit field in the firmware,
which still risks an overflow, but if the firmware is written
to expect unsigned values, it can at least last until y2106,
and there is not much we can do about it.

This changes do_gettimeofday() to ktime_get_real_seconds(), which
at least simplifies the code a bit, and avoids the deprecated
interface. I'm adding a comment about the overflow to document
what happens.

Signed-off-by: Arnd Bergmann 
---
Originally submitted in November 2017, no reply.
Sent again in January, still no reply.

Resending once more now, could you please apply the trivial patch?
---
 drivers/scsi/esas2r/esas2r_init.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/esas2r/esas2r_init.c 
b/drivers/scsi/esas2r/esas2r_init.c
index 9dffcb28c9b7..9db645dde35e 100644
--- a/drivers/scsi/esas2r/esas2r_init.c
+++ b/drivers/scsi/esas2r/esas2r_init.c
@@ -1202,8 +1202,6 @@ static bool esas2r_format_init_msg(struct esas2r_adapter 
*a,
case ESAS2R_INIT_MSG_START:
case ESAS2R_INIT_MSG_REINIT:
{
-   struct timeval now;
-   do_gettimeofday();
esas2r_hdebug("CFG init");
esas2r_build_cfg_req(a,
 rq,
@@ -1212,7 +1210,8 @@ static bool esas2r_format_init_msg(struct esas2r_adapter 
*a,
 NULL);
ci = (struct atto_vda_cfg_init *)>vrq->cfg.data.init;
ci->sgl_page_size = cpu_to_le32(sgl_page_size);
-   ci->epoch_time = cpu_to_le32(now.tv_sec);
+   /* firmware interface overflows in y2106 */
+   ci->epoch_time = cpu_to_le32(ktime_get_real_seconds());
rq->flags |= RF_FAILURE_OK;
a->init_msg = ESAS2R_INIT_MSG_INIT;
break;
-- 
2.9.0

Re: [Patch v2] Storvsc: Select channel based on available percentage of ring buffer to write

[Stephen Hemminger]

On Thu, 19 Apr 2018 14:54:24 -0700
Long Li  wrote:

> From: Long Li 
> 
> This is a best effort for estimating on how busy the ring buffer is for
> that channel, based on available buffer to write in percentage. It is still
> possible that at the time of actual ring buffer write, the space may not be
> available due to other processes may be writing at the time.
> 
> Selecting a channel based on how full it is can reduce the possibility that
> a ring buffer write will fail, and avoid the situation a channel is over
> busy.
> 
> Now it's possible that storvsc can use a smaller ring buffer size
> (e.g. 40k bytes) to take advantage of cache locality.
> 
> Changes.
> v2: Pre-allocate struct cpumask on the heap.
> Struct cpumask is a big structure (1k bytes) when CONFIG_NR_CPUS=8192 (default
> value when CONFIG_MAXSMP=y). Don't use kernel stack for it by pre-allocating
> them using kmalloc when channels are first initialized.
> 
> Signed-off-by: Long Li 

Reviewed-by: Stephen Hemminger 

[Bug 199435] HPSA + P420i resetting logical Direct-Access never complete

[bugzilla-daemon]

https://bugzilla.kernel.org/show_bug.cgi?id=199435

--- Comment #7 from Anthony Hausman (anthonyhaussm...@gmail.com) ---
I had a similar stack trace:

Apr 20 14:57:18 kernel: INFO: task jbd2/sdt-8:10890 blocked for more than 120
seconds.
Apr 20 14:57:18 kernel:   Tainted: G   OE   4.11.0-14-generic
#20~16.04.1-Ubuntu
Apr 20 14:57:18 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
Apr 20 14:57:18 kernel: jbd2/sdt-8  D0 10890  2 0x
Apr 20 14:57:18 kernel: Call Trace:
Apr 20 14:57:18 kernel:  __schedule+0x3b9/0x8f0
Apr 20 14:57:18 kernel:  schedule+0x36/0x80
Apr 20 14:57:18 kernel:  jbd2_journal_commit_transaction+0x241/0x1830
Apr 20 14:57:18 kernel:  ? update_load_avg+0x84/0x560
Apr 20 14:57:18 kernel:  ? update_load_avg+0x84/0x560
Apr 20 14:57:18 kernel:  ? dequeue_entity+0xed/0x4c0
Apr 20 14:57:18 kernel:  ? wake_atomic_t_function+0x60/0x60
Apr 20 14:57:18 kernel:  ? lock_timer_base+0x7d/0xa0
Apr 20 14:57:18 kernel:  kjournald2+0xca/0x250
Apr 20 14:57:18 kernel:  ? kjournald2+0xca/0x250
Apr 20 14:57:18 kernel:  ? wake_atomic_t_function+0x60/0x60
Apr 20 14:57:18 kernel:  kthread+0x109/0x140
Apr 20 14:57:18 kernel:  ? commit_timeout+0x10/0x10
Apr 20 14:57:18 kernel:  ? kthread_create_on_node+0x70/0x70
Apr 20 14:57:18 kernel:  ret_from_fork+0x25/0x30
Apr 20 14:57:18 kernel: INFO: task task:13497 blocked for more than 120
seconds.
Apr 20 14:57:18 kernel:   Tainted: G   OE   4.11.0-14-generic
#20~16.04.1-Ubuntu
Apr 20 14:57:18 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
Apr 20 14:57:18 kernel: taskD0 13497  13196 0x
Apr 20 14:57:18 kernel: Call Trace:
Apr 20 14:57:18 kernel:  __schedule+0x3b9/0x8f0
Apr 20 14:57:18 kernel:  schedule+0x36/0x80
Apr 20 14:57:18 kernel:  rwsem_down_write_failed+0x237/0x3b0
Apr 20 14:57:18 kernel:  ? copy_page_to_iter_iovec+0x97/0x170
Apr 20 14:57:18 kernel:  call_rwsem_down_write_failed+0x17/0x30
Apr 20 14:57:18 kernel:  ? call_rwsem_down_write_failed+0x17/0x30
Apr 20 14:57:18 kernel:  down_write+0x2d/0x40
Apr 20 14:57:18 kernel:  ext4_file_write_iter+0x70/0x3c0
Apr 20 14:57:18 kernel:  ? futex_wake+0x90/0x170
Apr 20 14:57:18 kernel:  new_sync_write+0xd3/0x130
Apr 20 14:57:18 kernel:  __vfs_write+0x26/0x40
Apr 20 14:57:18 kernel:  vfs_write+0xb8/0x1b0
Apr 20 14:57:18 kernel:  SyS_pwrite64+0x95/0xb0
Apr 20 14:57:18 kernel:  entry_SYSCALL_64_fastpath+0x1e/0xad
Apr 20 14:57:18 kernel: RIP: 0033:0x7fa085d92d23
Apr 20 14:57:18 kernel: RSP: 002b:7fa0801acc90 EFLAGS: 0293 ORIG_RAX:
0012
Apr 20 14:57:18 kernel: RAX: ffda RBX: 7fa0480009d0 RCX:
7fa085d92d23
Apr 20 14:57:18 kernel: RDX: 0200 RSI: 7fa004000b30 RDI:
000f
Apr 20 14:57:18 kernel: RBP: 7fa0801ad060 R08: 7fa0801acd2c R09:
0001
Apr 20 14:57:18 kernel: R10: 0001f86be000 R11: 0293 R12:
7fa0040014c0
Apr 20 14:57:18 kernel: R13: 7fa004000d80 R14: 002e R15:
7fa0480009d0
Apr 20 14:57:18 kernel: INFO: task task:13499 blocked for more than 120
seconds.
Apr 20 14:57:18 kernel:   Tainted: G   OE   4.11.0-14-generic
#20~16.04.1-Ubuntu
Apr 20 14:57:18 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
Apr 20 14:57:18 kernel: taskD0 13499  13196 0x
Apr 20 14:57:18 kernel: Call Trace:
Apr 20 14:57:18 kernel:  __schedule+0x3b9/0x8f0
Apr 20 14:57:18 kernel:  schedule+0x36/0x80
Apr 20 14:57:18 kernel:  rwsem_down_write_failed+0x237/0x3b0
Apr 20 14:57:18 kernel:  ? copy_page_to_iter_iovec+0x97/0x170
Apr 20 14:57:18 kernel:  call_rwsem_down_write_failed+0x17/0x30
Apr 20 14:57:18 kernel:  ? call_rwsem_down_write_failed+0x17/0x30
Apr 20 14:57:18 kernel:  down_write+0x2d/0x40
Apr 20 14:57:18 kernel:  ext4_file_write_iter+0x70/0x3c0
Apr 20 14:57:18 kernel:  ? futex_wake+0x90/0x170
Apr 20 14:57:18 kernel:  new_sync_write+0xd3/0x130
Apr 20 14:57:18 kernel:  __vfs_write+0x26/0x40
Apr 20 14:57:18 kernel:  vfs_write+0xb8/0x1b0
Apr 20 14:57:18 kernel:  SyS_pwrite64+0x95/0xb0
Apr 20 14:57:18 kernel:  entry_SYSCALL_64_fastpath+0x1e/0xad
Apr 20 14:57:18 kernel: RIP: 0033:0x7fa085d92d23
Apr 20 14:57:18 kernel: RSP: 002b:7fa07f9abc90 EFLAGS: 0293 ORIG_RAX:
0012
Apr 20 14:57:18 kernel: RAX: ffda RBX: 7f9fac008d00 RCX:
7fa085d92d23
Apr 20 14:57:18 kernel: RDX: 0200 RSI: 7fa0080013b0 RDI:
000f
Apr 20 14:57:18 kernel: RBP: 7fa07f9ac060 R08: 7fa07f9abd2c R09:
0001
Apr 20 14:57:18 kernel: R10: 000219541000 R11: 0293 R12:
7fa008001140
Apr 20 14:57:18 kernel: R13: 7fa0080008c0 R14: 002e R15:
7f9fac008d00
Apr 20 14:57:18 kernel: INFO: task task:13510 blocked for more than 120
seconds.
Apr 20 14:57:18 kernel:   Tainted: G   OE   4.11.0-14-generic
#20~16.04.1-Ubuntu
Apr 20 14:57:18 kernel: "echo 0 > 

Re: [PATCH] isci: Fix infinite loop in while loop

[Colin Ian King]

On 20/04/18 10:45, James Bottomley wrote:
> On Fri, 2018-04-20 at 10:03 +0100, Colin King wrote:
>> From: Colin Ian King 
>>
>> In the case when the phy_mask is bitwise anded with the
>> phy_index bit is zero the continue statement currently jumps
>> to the next iteration of the while loop and phy_index is
>> never actually incremented, potentially causing an infinite
>> loop if phy_index is less than SCI_MAX_PHS. Fix this by
>> jumping to the increment of phy_index.
>>
>> [ The goto is used to save one more level of nesting that
>> makes the code far wider than 80 columns. ]
> 
> what's wrong with replacing the while() with a for() that just works
> (removing the increment at the end).  This is effectively open coding a
> for loop anyway, which is a pattern we wouldn't want replicated.
> 
> James
> 
Good point, V2 en-route.

[PATCH][V2] isci: Fix infinite loop in while loop

[Colin King]

From: Colin Ian King 

In the case when the phy_mask is bitwise anded with the
phy_index bit is zero the continue statement currently jumps
to the next iteration of the while loop and phy_index is
never actually incremented, potentially causing an infinite
loop if phy_index is less than SCI_MAX_PHS. Fix this by turning
the while loop into a for loop.

Signed-off-by: Colin Ian King 
---
 drivers/scsi/isci/port_config.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/scsi/isci/port_config.c b/drivers/scsi/isci/port_config.c
index edb7be786c65..9e8de1462593 100644
--- a/drivers/scsi/isci/port_config.c
+++ b/drivers/scsi/isci/port_config.c
@@ -291,7 +291,7 @@ sci_mpc_agent_validate_phy_configuration(struct isci_host 
*ihost,
 * Note: We have not moved the current phy_index so we will 
actually
 *   compare the startting phy with itself.
 *   This is expected and required to add the phy to the 
port. */
-   while (phy_index < SCI_MAX_PHYS) {
+   for (; phy_index < SCI_MAX_PHYS; phy_index++) {
if ((phy_mask & (1 << phy_index)) == 0)
continue;
sci_phy_get_sas_address(>phys[phy_index],
@@ -311,7 +311,6 @@ sci_mpc_agent_validate_phy_configuration(struct isci_host 
*ihost,
  >phys[phy_index]);
 
assigned_phy_mask |= (1 << phy_index);
-   phy_index++;
}
 
}
-- 
2.17.0

Re: [PATCH] bsg referencing bus driver module

[James Bottomley]

On Thu, 2018-04-19 at 15:10 -0700, Anatoliy Glagolev wrote:
> Updated: rebased on recent Linux, cc-ed maintainers per instructions
> in MAINTAINERS file
> 
> From df939b80d02bf37b21efaaef8ede86cfd39b0cb8 Mon Sep 17 00:00:00
> 2001
> From: Anatoliy Glagolev 
> Date: Thu, 19 Apr 2018 15:06:06 -0600
> Subject: [PATCH] bsg referencing parent module
> 
> Fixing a bug when bsg layer holds the last reference to device
> when the device's module has been unloaded. Upon dropping the
> reference the device's release function may touch memory of
> the unloaded module.
> ---
>  block/bsg-lib.c  | 24 ++--
>  block/bsg.c  | 29 ++---
>  drivers/scsi/scsi_transport_fc.c |  8 ++--
>  include/linux/bsg-lib.h  |  4 
>  include/linux/bsg.h  |  5 +
>  5 files changed, 63 insertions(+), 7 deletions(-)
> 
> diff --git a/block/bsg-lib.c b/block/bsg-lib.c
> index fc2e5ff..90c28fd 100644
> --- a/block/bsg-lib.c
> +++ b/block/bsg-lib.c
> @@ -309,6 +309,25 @@ struct request_queue *bsg_setup_queue(struct
> device *dev, const char *name,
>   bsg_job_fn *job_fn, int dd_job_size,
>   void (*release)(struct device *))
>  {
> + return bsg_setup_queue_ex(dev, name, job_fn, dd_job_size, release,
> + NULL);
> +}
> +EXPORT_SYMBOL_GPL(bsg_setup_queue);
> +
> +/**
> + * bsg_setup_queue - Create and add the bsg hooks so we can receive
> requests
> + * @dev: device to attach bsg device to
> + * @name: device to give bsg device
> + * @job_fn: bsg job handler
> + * @dd_job_size: size of LLD data needed for each job
> + * @release: @dev release function
> + * @dev_module: @dev's module
> + */
> +struct request_queue *bsg_setup_queue_ex(struct device *dev, const
> char *name,
> + bsg_job_fn *job_fn, int dd_job_size,
> + void (*release)(struct device *),
> + struct module *dev_module)

This patch isn't applyable because your mailer has changed all the tabs
to spaces.

I also think there's no need to do it this way.  I think what we need
is for fc_bsg_remove() to wait until the bsg queue is drained.  It does
look like the author thought this happened otherwise the code wouldn't
have the note.  If we fix it that way we can do the same thing in all
the other transport classes that use bsg (which all have a similar
issue).

James

Re: [PATCH] isci: Fix infinite loop in while loop

[James Bottomley]

On Fri, 2018-04-20 at 10:03 +0100, Colin King wrote:
> From: Colin Ian King 
> 
> In the case when the phy_mask is bitwise anded with the
> phy_index bit is zero the continue statement currently jumps
> to the next iteration of the while loop and phy_index is
> never actually incremented, potentially causing an infinite
> loop if phy_index is less than SCI_MAX_PHS. Fix this by
> jumping to the increment of phy_index.
> 
> [ The goto is used to save one more level of nesting that
> makes the code far wider than 80 columns. ]

what's wrong with replacing the while() with a for() that just works
(removing the increment at the end).  This is effectively open coding a
for loop anyway, which is a pattern we wouldn't want replicated.

James

[PATCH] isci: Fix infinite loop in while loop

[Colin King]

From: Colin Ian King 

In the case when the phy_mask is bitwise anded with the
phy_index bit is zero the continue statement currently jumps
to the next iteration of the while loop and phy_index is
never actually incremented, potentially causing an infinite
loop if phy_index is less than SCI_MAX_PHS. Fix this by
jumping to the increment of phy_index.

[ The goto is used to save one more level of nesting that
makes the code far wider than 80 columns. ]

Fixes: 80aebef7c112 ("[SCSI] isci: Fix a infinite loop.")

Signed-off-by: Colin Ian King 
---
 drivers/scsi/isci/port_config.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/isci/port_config.c b/drivers/scsi/isci/port_config.c
index edb7be786c65..55dc7c1dbc2b 100644
--- a/drivers/scsi/isci/port_config.c
+++ b/drivers/scsi/isci/port_config.c
@@ -293,7 +293,7 @@ sci_mpc_agent_validate_phy_configuration(struct isci_host 
*ihost,
 *   This is expected and required to add the phy to the 
port. */
while (phy_index < SCI_MAX_PHYS) {
if ((phy_mask & (1 << phy_index)) == 0)
-   continue;
+   goto next_index;
sci_phy_get_sas_address(>phys[phy_index],
 _assigned_address);
 
@@ -311,6 +311,7 @@ sci_mpc_agent_validate_phy_configuration(struct isci_host 
*ihost,
  >phys[phy_index]);
 
assigned_phy_mask |= (1 << phy_index);
+next_index:
phy_index++;
}
 
-- 
2.17.0

[PATCH 3/3] scsi: avoid to hold host-wide counter of host_busy for scsi_mq

[Ming Lei]

It isn't necessary to check the host depth in scsi_queue_rq() any more
since it has been respected by blk-mq before calling scsi_queue_rq() via
getting driver tag.

Lots of LUNs may attach to same host, and per-host IOPS may reach millions
level, so we should avoid to this expensive atomic operations on the
hostwide counter in IO path.

This patch implemens scsi_host_busy() via blk_mq_tagset_busy_iter() for
reading the count of busy IOs for scsi_mq.

It is observed that IOPS is increased by 15% in IO test on scsi_debug
(32 LUNs, 32 submit queues, 1024 can_queue, libaio/dio) in one
dual-socket system.

Cc: Omar Sandoval ,
Cc: "Martin K. Petersen" ,
Cc: James Bottomley ,
Cc: Christoph Hellwig ,
Cc: Don Brace 
Cc: Kashyap Desai 
Cc: Mike Snitzer 
Cc: Hannes Reinecke 
Cc: Laurence Oberman 
Signed-off-by: Ming Lei 
---
 drivers/scsi/hosts.c| 24 +++-
 drivers/scsi/scsi_lib.c | 23 +--
 2 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 69beb30205f1..ad56e2b10ac8 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -564,13 +564,35 @@ struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
 }
 EXPORT_SYMBOL(scsi_host_get);
 
+struct scsi_host_mq_in_flight {
+   int cnt;
+};
+
+static void scsi_host_check_in_flight(struct request *rq, void *data,
+   bool reserved)
+{
+   struct scsi_host_mq_in_flight *in_flight = data;
+
+   if (blk_mq_request_started(rq))
+   in_flight->cnt++;
+}
+
 /**
  * scsi_host_busy - Return the host busy counter
  * @shost: Pointer to Scsi_Host to inc.
  **/
 int scsi_host_busy(struct Scsi_Host *shost)
 {
-   return atomic_read(>host_busy);
+   struct scsi_host_mq_in_flight in_flight = {
+   .cnt = 0,
+   };
+
+   if (!shost->use_blk_mq)
+   return atomic_read(>host_busy);
+
+   blk_mq_tagset_busy_iter(>tag_set, scsi_host_check_in_flight,
+   _flight);
+   return in_flight.cnt;
 }
 EXPORT_SYMBOL(scsi_host_busy);
 
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 0dfec0dedd5e..dc437c642934 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -345,7 +345,8 @@ static void scsi_dec_host_busy(struct Scsi_Host *shost)
unsigned long flags;
 
rcu_read_lock();
-   atomic_dec(>host_busy);
+   if (!shost->use_blk_mq)
+   atomic_dec(>host_busy);
if (unlikely(scsi_host_in_recovery(shost))) {
spin_lock_irqsave(shost->host_lock, flags);
if (shost->host_failed || shost->host_eh_scheduled)
@@ -444,7 +445,12 @@ static inline bool scsi_target_is_busy(struct scsi_target 
*starget)
 
 static inline bool scsi_host_is_busy(struct Scsi_Host *shost)
 {
-   if (shost->can_queue > 0 &&
+   /*
+* blk-mq can handle host queue busy efficiently via host-wide driver
+* tag allocation
+*/
+
+   if (!shost->use_blk_mq && shost->can_queue > 0 &&
atomic_read(>host_busy) >= shost->can_queue)
return true;
if (atomic_read(>host_blocked) > 0)
@@ -1539,9 +1545,12 @@ static inline int scsi_host_queue_ready(struct 
request_queue *q,
if (scsi_host_in_recovery(shost))
return 0;
 
-   busy = atomic_inc_return(>host_busy) - 1;
+   if (!shost->use_blk_mq)
+   busy = atomic_inc_return(>host_busy) - 1;
+   else
+   busy = 0;
if (atomic_read(>host_blocked) > 0) {
-   if (busy)
+   if (busy || scsi_host_busy(shost))
goto starved;
 
/*
@@ -1555,7 +1564,7 @@ static inline int scsi_host_queue_ready(struct 
request_queue *q,
 "unblocking host at zero depth\n"));
}
 
-   if (shost->can_queue > 0 && busy >= shost->can_queue)
+   if (!shost->use_blk_mq && shost->can_queue > 0 && busy >= 
shost->can_queue)
goto starved;
if (shost->host_self_blocked)
goto starved;
@@ -1641,7 +1650,9 @@ static void scsi_kill_request(struct request *req, struct 
request_queue *q)
 * with the locks as normal issue path does.
 */
atomic_inc(>device_busy);
-   atomic_inc(>host_busy);
+
+   if (!shost->use_blk_mq)
+   atomic_inc(>host_busy);
if (starget->can_queue > 0)
atomic_inc(>target_busy);
 
-- 
2.9.5

[PATCH 2/3] scsi: read host_busy via scsi_host_busy()

[Ming Lei]

No functional change, just replace the direct read of scsi_host->host_busy
with scsi_host_busy().

Cc: Omar Sandoval ,
Cc: "Martin K. Petersen" ,
Cc: James Bottomley ,
Cc: Christoph Hellwig ,
Cc: Don Brace 
Cc: Kashyap Desai 
Cc: Mike Snitzer 
Cc: Hannes Reinecke 
Cc: Laurence Oberman 
Signed-off-by: Ming Lei 
---
 drivers/scsi/advansys.c   | 8 
 drivers/scsi/libsas/sas_scsi_host.c   | 4 ++--
 drivers/scsi/megaraid/megaraid_sas_base.c | 2 +-
 drivers/scsi/mpt3sas/mpt3sas_base.c   | 4 ++--
 drivers/scsi/qlogicpti.c  | 2 +-
 drivers/scsi/scsi.c   | 2 +-
 drivers/scsi/scsi_error.c | 6 +++---
 drivers/scsi/scsi_sysfs.c | 2 +-
 8 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c
index 24e57e770432..38ee024cbfc7 100644
--- a/drivers/scsi/advansys.c
+++ b/drivers/scsi/advansys.c
@@ -2416,8 +2416,8 @@ static void asc_prt_scsi_host(struct Scsi_Host *s)
struct asc_board *boardp = shost_priv(s);
 
printk("Scsi_Host at addr 0x%p, device %s\n", s, dev_name(boardp->dev));
-   printk(" host_busy %u, host_no %d,\n",
-  atomic_read(>host_busy), s->host_no);
+   printk(" host_busy %d, host_no %d,\n",
+  scsi_host_busy(s), s->host_no);
 
printk(" base 0x%lx, io_port 0x%lx, irq %d,\n",
   (ulong)s->base, (ulong)s->io_port, boardp->irq);
@@ -3182,8 +3182,8 @@ static void asc_prt_driver_conf(struct seq_file *m, 
struct Scsi_Host *shost)
shost->host_no);
 
seq_printf(m,
-  " host_busy %u, max_id %u, max_lun %llu, max_channel %u\n",
-  atomic_read(>host_busy), shost->max_id,
+  " host_busy %d, max_id %u, max_lun %llu, max_channel %u\n",
+  scsi_host_busy(shost), shost->max_id,
   shost->max_lun, shost->max_channel);
 
seq_printf(m,
diff --git a/drivers/scsi/libsas/sas_scsi_host.c 
b/drivers/scsi/libsas/sas_scsi_host.c
index ceab5e5c41c2..33229348dcb6 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -759,7 +759,7 @@ void sas_scsi_recover_host(struct Scsi_Host *shost)
spin_unlock_irq(shost->host_lock);
 
SAS_DPRINTK("Enter %s busy: %d failed: %d\n",
-   __func__, atomic_read(>host_busy), 
shost->host_failed);
+   __func__, scsi_host_busy(shost), shost->host_failed);
/*
 * Deal with commands that still have SAS tasks (i.e. they didn't
 * complete via the normal sas_task completion mechanism),
@@ -801,7 +801,7 @@ void sas_scsi_recover_host(struct Scsi_Host *shost)
goto retry;
 
SAS_DPRINTK("--- Exit %s: busy: %d failed: %d tries: %d\n",
-   __func__, atomic_read(>host_busy),
+   __func__, scsi_host_busy(shost),
shost->host_failed, tries);
 }
 
diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c 
b/drivers/scsi/megaraid/megaraid_sas_base.c
index b89c6e6c0589..008a3bdfa948 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -2822,7 +2822,7 @@ static int megasas_reset_bus_host(struct scsi_cmnd *scmd)
"SCSI command pointer: (%p)\t SCSI host state: %d\t"
" SCSI host busy: %d\t FW outstanding: %d\n",
scmd, scmd->device->host->shost_state,
-   atomic_read((atomic_t *)>device->host->host_busy),
+   scsi_host_busy(scmd->device->host),
atomic_read(>fw_outstanding));
 
/*
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c 
b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 61f93a134956..b7325355df8e 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -3260,7 +3260,7 @@ _base_recovery_check(struct MPT3SAS_ADAPTER *ioc)
 * See _wait_for_commands_to_complete() call with regards to this code.
 */
if (ioc->shost_recovery && ioc->pending_io_count) {
-   ioc->pending_io_count = atomic_read(>shost->host_busy);
+   ioc->pending_io_count = scsi_host_busy(ioc->shost);
if (ioc->pending_io_count == 0)
wake_up(>reset_wq);
}
@@ -6658,7 +6658,7 @@ mpt3sas_wait_for_commands_to_complete(struct 
MPT3SAS_ADAPTER *ioc)
return;
 
/* pending command count */
-   ioc->pending_io_count = atomic_read(>shost->host_busy);
+   ioc->pending_io_count = scsi_host_busy(ioc->shost);
 
if (!ioc->pending_io_count)
return;
diff --git a/drivers/scsi/qlogicpti.c b/drivers/scsi/qlogicpti.c
index 

[PATCH 0/3] scsi: scsi-mq: don't hold host_busy in IO path

[Ming Lei]

Hi,

This patches removes the expensive atomic opeation on host-wide counter
of .host_busy for scsi-mq, and it is observed that IOPS can be increased by
15% with this change in IO test over scsi_debug.


Ming Lei (3):
  scsi: introduce scsi_host_busy()
  scsi: read host_busy via scsi_host_busy()
  scsi: avoid to hold host-wide counter of host_busy for scsi_mq

 drivers/scsi/advansys.c   |  8 
 drivers/scsi/hosts.c  | 32 +++
 drivers/scsi/libsas/sas_scsi_host.c   |  4 ++--
 drivers/scsi/megaraid/megaraid_sas_base.c |  2 +-
 drivers/scsi/mpt3sas/mpt3sas_base.c   |  4 ++--
 drivers/scsi/qlogicpti.c  |  2 +-
 drivers/scsi/scsi.c   |  2 +-
 drivers/scsi/scsi_error.c |  6 +++---
 drivers/scsi/scsi_lib.c   | 23 --
 drivers/scsi/scsi_sysfs.c |  2 +-
 include/scsi/scsi_host.h  |  1 +
 11 files changed, 65 insertions(+), 21 deletions(-)


Cc: Omar Sandoval ,
Cc: "Martin K. Petersen" ,
Cc: James Bottomley ,
Cc: Christoph Hellwig ,
Cc: Don Brace 
Cc: Kashyap Desai 
Cc: Mike Snitzer 
Cc: Hannes Reinecke 
Cc: Laurence Oberman 

-- 
2.9.5

[PATCH 1/3] scsi: introduce scsi_host_busy()

[Ming Lei]

This patch introduces SCSI middle layer API of scsi_host_busy() for
drivers to read the host-wide counter of scsi_host->host_busy.

Cc: Omar Sandoval ,
Cc: "Martin K. Petersen" ,
Cc: James Bottomley ,
Cc: Christoph Hellwig ,
Cc: Don Brace 
Cc: Kashyap Desai 
Cc: Mike Snitzer 
Cc: Hannes Reinecke 
Cc: Laurence Oberman 
Signed-off-by: Ming Lei 
---
 drivers/scsi/hosts.c | 10 ++
 include/scsi/scsi_host.h |  1 +
 2 files changed, 11 insertions(+)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 7649d63a1b8d..69beb30205f1 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -565,6 +565,16 @@ struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
 EXPORT_SYMBOL(scsi_host_get);
 
 /**
+ * scsi_host_busy - Return the host busy counter
+ * @shost: Pointer to Scsi_Host to inc.
+ **/
+int scsi_host_busy(struct Scsi_Host *shost)
+{
+   return atomic_read(>host_busy);
+}
+EXPORT_SYMBOL(scsi_host_busy);
+
+/**
  * scsi_host_put - dec a Scsi_Host ref count
  * @shost: Pointer to Scsi_Host to dec.
  **/
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 12f454cb6f61..44ab89268f30 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -758,6 +758,7 @@ extern void scsi_scan_host(struct Scsi_Host *);
 extern void scsi_rescan_device(struct device *);
 extern void scsi_remove_host(struct Scsi_Host *);
 extern struct Scsi_Host *scsi_host_get(struct Scsi_Host *);
+extern int scsi_host_busy(struct Scsi_Host *shost);
 extern void scsi_host_put(struct Scsi_Host *t);
 extern struct Scsi_Host *scsi_host_lookup(unsigned short);
 extern const char *scsi_host_state_name(enum scsi_host_state);
-- 
2.9.5