* [PATCH v3 01/12] Avoid that scsi_exit_rq() triggers a use-after-free
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
@ 2017-06-02 21:21 ` Bart Van Assche
2017-06-02 21:21 ` [PATCH v3 02/12] Split scsi_internal_device_block() Bart Van Assche
` (12 subsequent siblings)
13 siblings, 0 replies; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:21 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche, Hannes Reinecke,
Scott Bauer, Jan Kara, stable
Dereferencing shost from scsi_exit_rq() is not safe because the
SCSI host may already have been freed when scsi_exit_rq() is
called. Increasing the shost reference count in scsi_init_rq()
and dropping that reference in scsi_exit_rq() is nontrivial since
scsi_host_dev_release() may sleep and since scsi_exit_rq() may
be called from interrupt context. Since scsi_exit_rq() only needs
a single bit from shost, copy that bit into struct scsi_cmnd.
Reported-by: Scott Bauer <scott.bauer@intel.com>
Fixes: e9c787e65c0c ("scsi: allocate scsi_cmnd structures as part of struct request")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Scott Bauer <scott.bauer@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
---
drivers/scsi/scsi_lib.c | 47 +++++++++++++++++++++++++++++------------------
include/scsi/scsi_cmnd.h | 1 +
2 files changed, 30 insertions(+), 18 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 814a4bd8405d..cc9f792cd12b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -44,23 +44,23 @@ static struct kmem_cache *scsi_sense_isadma_cache;
static DEFINE_MUTEX(scsi_sense_cache_mutex);
static inline struct kmem_cache *
-scsi_select_sense_cache(struct Scsi_Host *shost)
+scsi_select_sense_cache(bool unchecked_isa_dma)
{
- return shost->unchecked_isa_dma ?
- scsi_sense_isadma_cache : scsi_sense_cache;
+ return unchecked_isa_dma ? scsi_sense_isadma_cache : scsi_sense_cache;
}
-static void scsi_free_sense_buffer(struct Scsi_Host *shost,
- unsigned char *sense_buffer)
+static void scsi_free_sense_buffer(bool unchecked_isa_dma,
+ unsigned char *sense_buffer)
{
- kmem_cache_free(scsi_select_sense_cache(shost), sense_buffer);
+ kmem_cache_free(scsi_select_sense_cache(unchecked_isa_dma),
+ sense_buffer);
}
-static unsigned char *scsi_alloc_sense_buffer(struct Scsi_Host *shost,
+static unsigned char *scsi_alloc_sense_buffer(bool unchecked_isa_dma,
gfp_t gfp_mask, int numa_node)
{
- return kmem_cache_alloc_node(scsi_select_sense_cache(shost), gfp_mask,
- numa_node);
+ return kmem_cache_alloc_node(scsi_select_sense_cache(unchecked_isa_dma),
+ gfp_mask, numa_node);
}
int scsi_init_sense_cache(struct Scsi_Host *shost)
@@ -68,7 +68,7 @@ int scsi_init_sense_cache(struct Scsi_Host *shost)
struct kmem_cache *cache;
int ret = 0;
- cache = scsi_select_sense_cache(shost);
+ cache = scsi_select_sense_cache(shost->unchecked_isa_dma);
if (cache)
return 0;
@@ -1137,6 +1137,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
{
void *buf = cmd->sense_buffer;
void *prot = cmd->prot_sdb;
+ unsigned int unchecked_isa_dma = cmd->flags & SCMD_UNCHECKED_ISA_DMA;
unsigned long flags;
/* zero out the cmd, except for the embedded scsi_request */
@@ -1146,6 +1147,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
cmd->device = dev;
cmd->sense_buffer = buf;
cmd->prot_sdb = prot;
+ cmd->flags = unchecked_isa_dma;
INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
cmd->jiffies_at_alloc = jiffies;
@@ -1846,6 +1848,7 @@ static int scsi_mq_prep_fn(struct request *req)
struct scsi_device *sdev = req->q->queuedata;
struct Scsi_Host *shost = sdev->host;
unsigned char *sense_buf = cmd->sense_buffer;
+ unsigned int unchecked_isa_dma = cmd->flags & SCMD_UNCHECKED_ISA_DMA;
struct scatterlist *sg;
/* zero out the cmd, except for the embedded scsi_request */
@@ -1857,6 +1860,7 @@ static int scsi_mq_prep_fn(struct request *req)
cmd->request = req;
cmd->device = sdev;
cmd->sense_buffer = sense_buf;
+ cmd->flags = unchecked_isa_dma;
cmd->tag = req->tag;
@@ -2003,10 +2007,13 @@ static int scsi_init_request(struct blk_mq_tag_set *set, struct request *rq,
unsigned int hctx_idx, unsigned int numa_node)
{
struct Scsi_Host *shost = set->driver_data;
+ const bool unchecked_isa_dma = shost->unchecked_isa_dma;
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
- cmd->sense_buffer =
- scsi_alloc_sense_buffer(shost, GFP_KERNEL, numa_node);
+ if (unchecked_isa_dma)
+ cmd->flags |= SCMD_UNCHECKED_ISA_DMA;
+ cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma,
+ GFP_KERNEL, numa_node);
if (!cmd->sense_buffer)
return -ENOMEM;
cmd->req.sense = cmd->sense_buffer;
@@ -2016,10 +2023,10 @@ static int scsi_init_request(struct blk_mq_tag_set *set, struct request *rq,
static void scsi_exit_request(struct blk_mq_tag_set *set, struct request *rq,
unsigned int hctx_idx)
{
- struct Scsi_Host *shost = set->driver_data;
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
- scsi_free_sense_buffer(shost, cmd->sense_buffer);
+ scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA,
+ cmd->sense_buffer);
}
static int scsi_map_queues(struct blk_mq_tag_set *set)
@@ -2092,11 +2099,15 @@ EXPORT_SYMBOL_GPL(__scsi_init_queue);
static int scsi_init_rq(struct request_queue *q, struct request *rq, gfp_t gfp)
{
struct Scsi_Host *shost = q->rq_alloc_data;
+ const bool unchecked_isa_dma = shost->unchecked_isa_dma;
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
memset(cmd, 0, sizeof(*cmd));
- cmd->sense_buffer = scsi_alloc_sense_buffer(shost, gfp, NUMA_NO_NODE);
+ if (unchecked_isa_dma)
+ cmd->flags |= SCMD_UNCHECKED_ISA_DMA;
+ cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma, gfp,
+ NUMA_NO_NODE);
if (!cmd->sense_buffer)
goto fail;
cmd->req.sense = cmd->sense_buffer;
@@ -2110,19 +2121,19 @@ static int scsi_init_rq(struct request_queue *q, struct request *rq, gfp_t gfp)
return 0;
fail_free_sense:
- scsi_free_sense_buffer(shost, cmd->sense_buffer);
+ scsi_free_sense_buffer(unchecked_isa_dma, cmd->sense_buffer);
fail:
return -ENOMEM;
}
static void scsi_exit_rq(struct request_queue *q, struct request *rq)
{
- struct Scsi_Host *shost = q->rq_alloc_data;
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
if (cmd->prot_sdb)
kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
- scsi_free_sense_buffer(shost, cmd->sense_buffer);
+ scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA,
+ cmd->sense_buffer);
}
struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index b379f93a2c48..16351de31243 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -56,6 +56,7 @@ struct scsi_pointer {
/* for scmd->flags */
#define SCMD_TAGGED (1 << 0)
+#define SCMD_UNCHECKED_ISA_DMA (1 << 1)
struct scsi_cmnd {
struct scsi_request req;
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 01/12] Avoid that scsi_exit_rq() triggers a use-after-free
@ 2017-06-02 21:21 ` Bart Van Assche
0 siblings, 0 replies; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:21 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche, Hannes Reinecke,
Scott Bauer, Jan Kara, stable
Dereferencing shost from scsi_exit_rq() is not safe because the
SCSI host may already have been freed when scsi_exit_rq() is
called. Increasing the shost reference count in scsi_init_rq()
and dropping that reference in scsi_exit_rq() is nontrivial since
scsi_host_dev_release() may sleep and since scsi_exit_rq() may
be called from interrupt context. Since scsi_exit_rq() only needs
a single bit from shost, copy that bit into struct scsi_cmnd.
Reported-by: Scott Bauer <scott.bauer@intel.com>
Fixes: e9c787e65c0c ("scsi: allocate scsi_cmnd structures as part of struct request")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Scott Bauer <scott.bauer@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: <stable@vger.kernel.org>
---
drivers/scsi/scsi_lib.c | 47 +++++++++++++++++++++++++++++------------------
include/scsi/scsi_cmnd.h | 1 +
2 files changed, 30 insertions(+), 18 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 814a4bd8405d..cc9f792cd12b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -44,23 +44,23 @@ static struct kmem_cache *scsi_sense_isadma_cache;
static DEFINE_MUTEX(scsi_sense_cache_mutex);
static inline struct kmem_cache *
-scsi_select_sense_cache(struct Scsi_Host *shost)
+scsi_select_sense_cache(bool unchecked_isa_dma)
{
- return shost->unchecked_isa_dma ?
- scsi_sense_isadma_cache : scsi_sense_cache;
+ return unchecked_isa_dma ? scsi_sense_isadma_cache : scsi_sense_cache;
}
-static void scsi_free_sense_buffer(struct Scsi_Host *shost,
- unsigned char *sense_buffer)
+static void scsi_free_sense_buffer(bool unchecked_isa_dma,
+ unsigned char *sense_buffer)
{
- kmem_cache_free(scsi_select_sense_cache(shost), sense_buffer);
+ kmem_cache_free(scsi_select_sense_cache(unchecked_isa_dma),
+ sense_buffer);
}
-static unsigned char *scsi_alloc_sense_buffer(struct Scsi_Host *shost,
+static unsigned char *scsi_alloc_sense_buffer(bool unchecked_isa_dma,
gfp_t gfp_mask, int numa_node)
{
- return kmem_cache_alloc_node(scsi_select_sense_cache(shost), gfp_mask,
- numa_node);
+ return kmem_cache_alloc_node(scsi_select_sense_cache(unchecked_isa_dma),
+ gfp_mask, numa_node);
}
int scsi_init_sense_cache(struct Scsi_Host *shost)
@@ -68,7 +68,7 @@ int scsi_init_sense_cache(struct Scsi_Host *shost)
struct kmem_cache *cache;
int ret = 0;
- cache = scsi_select_sense_cache(shost);
+ cache = scsi_select_sense_cache(shost->unchecked_isa_dma);
if (cache)
return 0;
@@ -1137,6 +1137,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
{
void *buf = cmd->sense_buffer;
void *prot = cmd->prot_sdb;
+ unsigned int unchecked_isa_dma = cmd->flags & SCMD_UNCHECKED_ISA_DMA;
unsigned long flags;
/* zero out the cmd, except for the embedded scsi_request */
@@ -1146,6 +1147,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
cmd->device = dev;
cmd->sense_buffer = buf;
cmd->prot_sdb = prot;
+ cmd->flags = unchecked_isa_dma;
INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
cmd->jiffies_at_alloc = jiffies;
@@ -1846,6 +1848,7 @@ static int scsi_mq_prep_fn(struct request *req)
struct scsi_device *sdev = req->q->queuedata;
struct Scsi_Host *shost = sdev->host;
unsigned char *sense_buf = cmd->sense_buffer;
+ unsigned int unchecked_isa_dma = cmd->flags & SCMD_UNCHECKED_ISA_DMA;
struct scatterlist *sg;
/* zero out the cmd, except for the embedded scsi_request */
@@ -1857,6 +1860,7 @@ static int scsi_mq_prep_fn(struct request *req)
cmd->request = req;
cmd->device = sdev;
cmd->sense_buffer = sense_buf;
+ cmd->flags = unchecked_isa_dma;
cmd->tag = req->tag;
@@ -2003,10 +2007,13 @@ static int scsi_init_request(struct blk_mq_tag_set *set, struct request *rq,
unsigned int hctx_idx, unsigned int numa_node)
{
struct Scsi_Host *shost = set->driver_data;
+ const bool unchecked_isa_dma = shost->unchecked_isa_dma;
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
- cmd->sense_buffer =
- scsi_alloc_sense_buffer(shost, GFP_KERNEL, numa_node);
+ if (unchecked_isa_dma)
+ cmd->flags |= SCMD_UNCHECKED_ISA_DMA;
+ cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma,
+ GFP_KERNEL, numa_node);
if (!cmd->sense_buffer)
return -ENOMEM;
cmd->req.sense = cmd->sense_buffer;
@@ -2016,10 +2023,10 @@ static int scsi_init_request(struct blk_mq_tag_set *set, struct request *rq,
static void scsi_exit_request(struct blk_mq_tag_set *set, struct request *rq,
unsigned int hctx_idx)
{
- struct Scsi_Host *shost = set->driver_data;
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
- scsi_free_sense_buffer(shost, cmd->sense_buffer);
+ scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA,
+ cmd->sense_buffer);
}
static int scsi_map_queues(struct blk_mq_tag_set *set)
@@ -2092,11 +2099,15 @@ EXPORT_SYMBOL_GPL(__scsi_init_queue);
static int scsi_init_rq(struct request_queue *q, struct request *rq, gfp_t gfp)
{
struct Scsi_Host *shost = q->rq_alloc_data;
+ const bool unchecked_isa_dma = shost->unchecked_isa_dma;
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
memset(cmd, 0, sizeof(*cmd));
- cmd->sense_buffer = scsi_alloc_sense_buffer(shost, gfp, NUMA_NO_NODE);
+ if (unchecked_isa_dma)
+ cmd->flags |= SCMD_UNCHECKED_ISA_DMA;
+ cmd->sense_buffer = scsi_alloc_sense_buffer(unchecked_isa_dma, gfp,
+ NUMA_NO_NODE);
if (!cmd->sense_buffer)
goto fail;
cmd->req.sense = cmd->sense_buffer;
@@ -2110,19 +2121,19 @@ static int scsi_init_rq(struct request_queue *q, struct request *rq, gfp_t gfp)
return 0;
fail_free_sense:
- scsi_free_sense_buffer(shost, cmd->sense_buffer);
+ scsi_free_sense_buffer(unchecked_isa_dma, cmd->sense_buffer);
fail:
return -ENOMEM;
}
static void scsi_exit_rq(struct request_queue *q, struct request *rq)
{
- struct Scsi_Host *shost = q->rq_alloc_data;
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
if (cmd->prot_sdb)
kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
- scsi_free_sense_buffer(shost, cmd->sense_buffer);
+ scsi_free_sense_buffer(cmd->flags & SCMD_UNCHECKED_ISA_DMA,
+ cmd->sense_buffer);
}
struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index b379f93a2c48..16351de31243 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -56,6 +56,7 @@ struct scsi_pointer {
/* for scmd->flags */
#define SCMD_TAGGED (1 << 0)
+#define SCMD_UNCHECKED_ISA_DMA (1 << 1)
struct scsi_cmnd {
struct scsi_request req;
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 02/12] Split scsi_internal_device_block()
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
2017-06-02 21:21 ` Bart Van Assche
@ 2017-06-02 21:21 ` Bart Van Assche
2017-06-02 21:21 ` [PATCH v3 03/12] Create two versions of scsi_internal_device_unblock() Bart Van Assche
` (11 subsequent siblings)
13 siblings, 0 replies; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:21 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche, Sreekanth Reddy
Instead of passing a "wait" argument to scsi_internal_device_block(),
split this function into a function that waits and a function that
doesn't wait. This will make it easier to serialize SCSI device state
changes through a mutex.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
---
drivers/scsi/mpt3sas/mpt3sas_scsih.c | 4 +-
drivers/scsi/scsi_lib.c | 73 +++++++++++++++++++++++-------------
include/scsi/scsi_device.h | 2 +-
3 files changed, 50 insertions(+), 29 deletions(-)
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index a5d872664257..c63bc5ccce37 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -2859,7 +2859,7 @@ _scsih_internal_device_block(struct scsi_device *sdev,
sas_device_priv_data->sas_target->handle);
sas_device_priv_data->block = 1;
- r = scsi_internal_device_block(sdev, false);
+ r = scsi_internal_device_block_nowait(sdev);
if (r == -EINVAL)
sdev_printk(KERN_WARNING, sdev,
"device_block failed with return(%d) for handle(0x%04x)\n",
@@ -2895,7 +2895,7 @@ _scsih_internal_device_unblock(struct scsi_device *sdev,
"performing a block followed by an unblock\n",
r, sas_device_priv_data->sas_target->handle);
sas_device_priv_data->block = 1;
- r = scsi_internal_device_block(sdev, false);
+ r = scsi_internal_device_block_nowait(sdev);
if (r)
sdev_printk(KERN_WARNING, sdev, "retried device_block "
"failed with return(%d) for handle(0x%04x)\n",
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index cc9f792cd12b..c9ce36d16df0 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2943,28 +2943,20 @@ scsi_target_resume(struct scsi_target *starget)
EXPORT_SYMBOL(scsi_target_resume);
/**
- * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state
- * @sdev: device to block
- * @wait: Whether or not to wait until ongoing .queuecommand() /
- * .queue_rq() calls have finished.
+ * scsi_internal_device_block_nowait - try to transition to the SDEV_BLOCK state
+ * @sdev: device to block
*
- * Block request made by scsi lld's to temporarily stop all
- * scsi commands on the specified device. May sleep.
+ * Pause SCSI command processing on the specified device. Does not sleep.
*
- * Returns zero if successful or error if not
+ * Returns zero if successful or a negative error code upon failure.
*
- * Notes:
- * This routine transitions the device to the SDEV_BLOCK state
- * (which must be a legal transition). When the device is in this
- * state, all commands are deferred until the scsi lld reenables
- * the device with scsi_device_unblock or device_block_tmo fires.
- *
- * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after
- * scsi_internal_device_block() has blocked a SCSI device and also
- * remove the rport mutex lock and unlock calls from srp_queuecommand().
+ * Notes:
+ * This routine transitions the device to the SDEV_BLOCK state (which must be
+ * a legal transition). When the device is in this state, command processing
+ * is paused until the device leaves the SDEV_BLOCK state. See also
+ * scsi_internal_device_unblock_nowait().
*/
-int
-scsi_internal_device_block(struct scsi_device *sdev, bool wait)
+int scsi_internal_device_block_nowait(struct scsi_device *sdev)
{
struct request_queue *q = sdev->request_queue;
unsigned long flags;
@@ -2984,21 +2976,50 @@ scsi_internal_device_block(struct scsi_device *sdev, bool wait)
* request queue.
*/
if (q->mq_ops) {
- if (wait)
- blk_mq_quiesce_queue(q);
- else
- blk_mq_stop_hw_queues(q);
+ blk_mq_stop_hw_queues(q);
} else {
spin_lock_irqsave(q->queue_lock, flags);
blk_stop_queue(q);
spin_unlock_irqrestore(q->queue_lock, flags);
- if (wait)
- scsi_wait_for_queuecommand(sdev);
}
return 0;
}
-EXPORT_SYMBOL_GPL(scsi_internal_device_block);
+EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
+
+/**
+ * scsi_internal_device_block - try to transition to the SDEV_BLOCK state
+ * @sdev: device to block
+ *
+ * Pause SCSI command processing on the specified device and wait until all
+ * ongoing scsi_request_fn() / scsi_queue_rq() calls have finished. May sleep.
+ *
+ * Returns zero if successful or a negative error code upon failure.
+ *
+ * Note:
+ * This routine transitions the device to the SDEV_BLOCK state (which must be
+ * a legal transition). When the device is in this state, command processing
+ * is paused until the device leaves the SDEV_BLOCK state. See also
+ * scsi_internal_device_unblock().
+ *
+ * To do: avoid that scsi_send_eh_cmnd() calls queuecommand() after
+ * scsi_internal_device_block() has blocked a SCSI device and also
+ * remove the rport mutex lock and unlock calls from srp_queuecommand().
+ */
+static int scsi_internal_device_block(struct scsi_device *sdev)
+{
+ struct request_queue *q = sdev->request_queue;
+ int err;
+
+ err = scsi_internal_device_block_nowait(sdev);
+ if (err == 0) {
+ if (q->mq_ops)
+ blk_mq_quiesce_queue(q);
+ else
+ scsi_wait_for_queuecommand(sdev);
+ }
+ return err;
+}
/**
* scsi_internal_device_unblock - resume a device after a block request
@@ -3055,7 +3076,7 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_unblock);
static void
device_block(struct scsi_device *sdev, void *data)
{
- scsi_internal_device_block(sdev, true);
+ scsi_internal_device_block(sdev);
}
static int
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 05641aebd181..6ce6888f3c69 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -472,7 +472,7 @@ static inline int scsi_device_created(struct scsi_device *sdev)
sdev->sdev_state == SDEV_CREATED_BLOCK;
}
-int scsi_internal_device_block(struct scsi_device *sdev, bool wait);
+int scsi_internal_device_block_nowait(struct scsi_device *sdev);
int scsi_internal_device_unblock(struct scsi_device *sdev,
enum scsi_device_state new_state);
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 03/12] Create two versions of scsi_internal_device_unblock()
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
2017-06-02 21:21 ` Bart Van Assche
2017-06-02 21:21 ` [PATCH v3 02/12] Split scsi_internal_device_block() Bart Van Assche
@ 2017-06-02 21:21 ` Bart Van Assche
2017-06-02 21:21 ` [PATCH v3 04/12] Protect SCSI device state changes with a mutex Bart Van Assche
` (10 subsequent siblings)
13 siblings, 0 replies; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:21 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche, Sreekanth Reddy
This will make it easier to serialize SCSI device state changes
through a mutex.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Sreekanth Reddy <sreekanth.reddy@broadcom.com>
---
drivers/scsi/mpt3sas/mpt3sas_scsih.c | 4 ++--
drivers/scsi/scsi_lib.c | 46 +++++++++++++++++++++++++-----------
include/scsi/scsi_device.h | 4 ++--
3 files changed, 36 insertions(+), 18 deletions(-)
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index c63bc5ccce37..22998cbd538f 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -2883,7 +2883,7 @@ _scsih_internal_device_unblock(struct scsi_device *sdev,
sdev_printk(KERN_WARNING, sdev, "device_unblock and setting to running, "
"handle(0x%04x)\n", sas_device_priv_data->sas_target->handle);
sas_device_priv_data->block = 0;
- r = scsi_internal_device_unblock(sdev, SDEV_RUNNING);
+ r = scsi_internal_device_unblock_nowait(sdev, SDEV_RUNNING);
if (r == -EINVAL) {
/* The device has been set to SDEV_RUNNING by SD layer during
* device addition but the request queue is still stopped by
@@ -2902,7 +2902,7 @@ _scsih_internal_device_unblock(struct scsi_device *sdev,
r, sas_device_priv_data->sas_target->handle);
sas_device_priv_data->block = 0;
- r = scsi_internal_device_unblock(sdev, SDEV_RUNNING);
+ r = scsi_internal_device_unblock_nowait(sdev, SDEV_RUNNING);
if (r)
sdev_printk(KERN_WARNING, sdev, "retried device_unblock"
" failed with return(%d) for handle(0x%04x)\n",
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index c9ce36d16df0..aa84b77e41dc 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -3022,24 +3022,22 @@ static int scsi_internal_device_block(struct scsi_device *sdev)
}
/**
- * scsi_internal_device_unblock - resume a device after a block request
+ * scsi_internal_device_unblock_nowait - resume a device after a block request
* @sdev: device to resume
- * @new_state: state to set devices to after unblocking
+ * @new_state: state to set the device to after unblocking
*
- * Called by scsi lld's or the midlayer to restart the device queue
- * for the previously suspended scsi device. Called from interrupt or
- * normal process context.
+ * Restart the device queue for a previously suspended SCSI device. Does not
+ * sleep.
*
- * Returns zero if successful or error if not.
+ * Returns zero if successful or a negative error code upon failure.
*
- * Notes:
- * This routine transitions the device to the SDEV_RUNNING state
- * or to one of the offline states (which must be a legal transition)
- * allowing the midlayer to goose the queue for this device.
+ * Notes:
+ * This routine transitions the device to the SDEV_RUNNING state or to one of
+ * the offline states (which must be a legal transition) allowing the midlayer
+ * to goose the queue for this device.
*/
-int
-scsi_internal_device_unblock(struct scsi_device *sdev,
- enum scsi_device_state new_state)
+int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
+ enum scsi_device_state new_state)
{
struct request_queue *q = sdev->request_queue;
unsigned long flags;
@@ -3071,7 +3069,27 @@ scsi_internal_device_unblock(struct scsi_device *sdev,
return 0;
}
-EXPORT_SYMBOL_GPL(scsi_internal_device_unblock);
+EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait);
+
+/**
+ * scsi_internal_device_unblock - resume a device after a block request
+ * @sdev: device to resume
+ * @new_state: state to set the device to after unblocking
+ *
+ * Restart the device queue for a previously suspended SCSI device. May sleep.
+ *
+ * Returns zero if successful or a negative error code upon failure.
+ *
+ * Notes:
+ * This routine transitions the device to the SDEV_RUNNING state or to one of
+ * the offline states (which must be a legal transition) allowing the midlayer
+ * to goose the queue for this device.
+ */
+static int scsi_internal_device_unblock(struct scsi_device *sdev,
+ enum scsi_device_state new_state)
+{
+ return scsi_internal_device_unblock_nowait(sdev, new_state);
+}
static void
device_block(struct scsi_device *sdev, void *data)
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 6ce6888f3c69..5f24dae2a8e1 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -473,8 +473,8 @@ static inline int scsi_device_created(struct scsi_device *sdev)
}
int scsi_internal_device_block_nowait(struct scsi_device *sdev);
-int scsi_internal_device_unblock(struct scsi_device *sdev,
- enum scsi_device_state new_state);
+int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
+ enum scsi_device_state new_state);
/* accessor functions for the SCSI parameters */
static inline int scsi_device_sync(struct scsi_device *sdev)
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 04/12] Protect SCSI device state changes with a mutex
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
` (2 preceding siblings ...)
2017-06-02 21:21 ` [PATCH v3 03/12] Create two versions of scsi_internal_device_unblock() Bart Van Assche
@ 2017-06-02 21:21 ` Bart Van Assche
2017-06-05 8:09 ` Christoph Hellwig
2017-06-02 21:21 ` [PATCH v3 05/12] Introduce scsi_start_queue() Bart Van Assche
` (9 subsequent siblings)
13 siblings, 1 reply; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:21 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche, Hannes Reinecke,
Johannes Thumshirn
Serializing SCSI device state changes avoids that two state changes
can occur concurrently, e.g. the state changes in scsi_target_block()
and __scsi_remove_device(). This serialization is essential to make
patch "Make __scsi_remove_device go straight from BLOCKED to DEL"
work reliably.
Enable this mechanism for all scsi_target_*block() callers but not
for the scsi_internal_device_unblock() calls from the mpt3sas driver
because that driver can call scsi_internal_device_unblock() from
atomic context.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
---
drivers/scsi/scsi_error.c | 8 +++++++-
drivers/scsi/scsi_lib.c | 27 +++++++++++++++++++++------
drivers/scsi/scsi_scan.c | 16 +++++++++-------
drivers/scsi/scsi_sysfs.c | 24 +++++++++++++++++++-----
drivers/scsi/scsi_transport_srp.c | 7 ++++---
drivers/scsi/sd.c | 7 +++++--
include/scsi/scsi_device.h | 1 +
7 files changed, 66 insertions(+), 24 deletions(-)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index ecc07dab893d..ac3196420435 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1628,11 +1628,17 @@ static void scsi_eh_offline_sdevs(struct list_head *work_q,
struct list_head *done_q)
{
struct scsi_cmnd *scmd, *next;
+ struct scsi_device *sdev;
list_for_each_entry_safe(scmd, next, work_q, eh_entry) {
sdev_printk(KERN_INFO, scmd->device, "Device offlined - "
"not ready after error recovery\n");
- scsi_device_set_state(scmd->device, SDEV_OFFLINE);
+ sdev = scmd->device;
+
+ mutex_lock(&sdev->state_mutex);
+ scsi_device_set_state(sdev, SDEV_OFFLINE);
+ mutex_unlock(&sdev->state_mutex);
+
scsi_eh_finish_cmd(scmd, done_q);
}
return;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index aa84b77e41dc..845d47244e70 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2881,7 +2881,12 @@ static void scsi_wait_for_queuecommand(struct scsi_device *sdev)
int
scsi_device_quiesce(struct scsi_device *sdev)
{
- int err = scsi_device_set_state(sdev, SDEV_QUIESCE);
+ int err;
+
+ mutex_lock(&sdev->state_mutex);
+ err = scsi_device_set_state(sdev, SDEV_QUIESCE);
+ mutex_unlock(&sdev->state_mutex);
+
if (err)
return err;
@@ -2909,10 +2914,11 @@ void scsi_device_resume(struct scsi_device *sdev)
* so assume the state is being managed elsewhere (for example
* device deleted during suspend)
*/
- if (sdev->sdev_state != SDEV_QUIESCE ||
- scsi_device_set_state(sdev, SDEV_RUNNING))
- return;
- scsi_run_queue(sdev->request_queue);
+ mutex_lock(&sdev->state_mutex);
+ if (sdev->sdev_state == SDEV_QUIESCE &&
+ scsi_device_set_state(sdev, SDEV_RUNNING) == 0)
+ scsi_run_queue(sdev->request_queue);
+ mutex_unlock(&sdev->state_mutex);
}
EXPORT_SYMBOL(scsi_device_resume);
@@ -3011,6 +3017,7 @@ static int scsi_internal_device_block(struct scsi_device *sdev)
struct request_queue *q = sdev->request_queue;
int err;
+ mutex_lock(&sdev->state_mutex);
err = scsi_internal_device_block_nowait(sdev);
if (err == 0) {
if (q->mq_ops)
@@ -3018,6 +3025,8 @@ static int scsi_internal_device_block(struct scsi_device *sdev)
else
scsi_wait_for_queuecommand(sdev);
}
+ mutex_unlock(&sdev->state_mutex);
+
return err;
}
@@ -3088,7 +3097,13 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_unblock_nowait);
static int scsi_internal_device_unblock(struct scsi_device *sdev,
enum scsi_device_state new_state)
{
- return scsi_internal_device_unblock_nowait(sdev, new_state);
+ int ret;
+
+ mutex_lock(&sdev->state_mutex);
+ ret = scsi_internal_device_unblock_nowait(sdev, new_state);
+ mutex_unlock(&sdev->state_mutex);
+
+ return ret;
}
static void
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 6f7128f49c30..e6de4eee97a3 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -231,6 +231,7 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget,
sdev->id = starget->id;
sdev->lun = lun;
sdev->channel = starget->channel;
+ mutex_init(&sdev->state_mutex);
sdev->sdev_state = SDEV_CREATED;
INIT_LIST_HEAD(&sdev->siblings);
INIT_LIST_HEAD(&sdev->same_target_siblings);
@@ -943,16 +944,17 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
/* set the device running here so that slave configure
* may do I/O */
+ mutex_lock(&sdev->state_mutex);
ret = scsi_device_set_state(sdev, SDEV_RUNNING);
- if (ret) {
+ if (ret)
ret = scsi_device_set_state(sdev, SDEV_BLOCK);
+ mutex_unlock(&sdev->state_mutex);
- if (ret) {
- sdev_printk(KERN_ERR, sdev,
- "in wrong state %s to complete scan\n",
- scsi_device_state_name(sdev->sdev_state));
- return SCSI_SCAN_NO_RESPONSE;
- }
+ if (ret) {
+ sdev_printk(KERN_ERR, sdev,
+ "in wrong state %s to complete scan\n",
+ scsi_device_state_name(sdev->sdev_state));
+ return SCSI_SCAN_NO_RESPONSE;
}
if (*bflags & BLIST_MS_192_BYTES_FOR_3F)
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 82dfe07b1d47..a91537a3abbf 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -719,7 +719,7 @@ static ssize_t
store_state_field(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
- int i;
+ int i, ret;
struct scsi_device *sdev = to_scsi_device(dev);
enum scsi_device_state state = 0;
@@ -734,9 +734,11 @@ store_state_field(struct device *dev, struct device_attribute *attr,
if (!state)
return -EINVAL;
- if (scsi_device_set_state(sdev, state))
- return -EINVAL;
- return count;
+ mutex_lock(&sdev->state_mutex);
+ ret = scsi_device_set_state(sdev, state);
+ mutex_unlock(&sdev->state_mutex);
+
+ return ret == 0 ? count : -EINVAL;
}
static ssize_t
@@ -1272,6 +1274,7 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev)
void __scsi_remove_device(struct scsi_device *sdev)
{
struct device *dev = &sdev->sdev_gendev;
+ int res;
/*
* This cleanup path is not reentrant and while it is impossible
@@ -1282,7 +1285,15 @@ void __scsi_remove_device(struct scsi_device *sdev)
return;
if (sdev->is_visible) {
- if (scsi_device_set_state(sdev, SDEV_CANCEL) != 0)
+ /*
+ * If scsi_internal_target_block() is running concurrently,
+ * wait until it has finished before changing the device state.
+ */
+ mutex_lock(&sdev->state_mutex);
+ res = scsi_device_set_state(sdev, SDEV_CANCEL);
+ mutex_unlock(&sdev->state_mutex);
+
+ if (res != 0)
return;
bsg_unregister_queue(sdev->request_queue);
@@ -1298,7 +1309,10 @@ void __scsi_remove_device(struct scsi_device *sdev)
* scsi_run_queue() invocations have finished before tearing down the
* device.
*/
+ mutex_lock(&sdev->state_mutex);
scsi_device_set_state(sdev, SDEV_DEL);
+ mutex_unlock(&sdev->state_mutex);
+
blk_cleanup_queue(sdev->request_queue);
cancel_work_sync(&sdev->requeue_work);
diff --git a/drivers/scsi/scsi_transport_srp.c b/drivers/scsi/scsi_transport_srp.c
index 3c5d89852e9f..f617021c94f7 100644
--- a/drivers/scsi/scsi_transport_srp.c
+++ b/drivers/scsi/scsi_transport_srp.c
@@ -554,11 +554,12 @@ int srp_reconnect_rport(struct srp_rport *rport)
* invoking scsi_target_unblock() won't change the state of
* these devices into running so do that explicitly.
*/
- spin_lock_irq(shost->host_lock);
- __shost_for_each_device(sdev, shost)
+ shost_for_each_device(sdev, shost) {
+ mutex_lock(&sdev->state_mutex);
if (sdev->sdev_state == SDEV_OFFLINE)
sdev->sdev_state = SDEV_RUNNING;
- spin_unlock_irq(shost->host_lock);
+ mutex_unlock(&sdev->state_mutex);
+ }
} else if (rport->state == SRP_RPORT_RUNNING) {
/*
* srp_reconnect_rport() has been invoked with fast_io_fail
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index f9d1432d7cc5..aea55f5afed0 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1798,8 +1798,9 @@ static void sd_eh_reset(struct scsi_cmnd *scmd)
static int sd_eh_action(struct scsi_cmnd *scmd, int eh_disp)
{
struct scsi_disk *sdkp = scsi_disk(scmd->request->rq_disk);
+ struct scsi_device *sdev = scmd->device;
- if (!scsi_device_online(scmd->device) ||
+ if (!scsi_device_online(sdev) ||
!scsi_medium_access_command(scmd) ||
host_byte(scmd->result) != DID_TIME_OUT ||
eh_disp != SUCCESS)
@@ -1825,7 +1826,9 @@ static int sd_eh_action(struct scsi_cmnd *scmd, int eh_disp)
if (sdkp->medium_access_timed_out >= sdkp->max_medium_access_timeouts) {
scmd_printk(KERN_ERR, scmd,
"Medium access timeout failure. Offlining disk!\n");
- scsi_device_set_state(scmd->device, SDEV_OFFLINE);
+ mutex_lock(&sdev->state_mutex);
+ scsi_device_set_state(sdev, SDEV_OFFLINE);
+ mutex_unlock(&sdev->state_mutex);
return SUCCESS;
}
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 5f24dae2a8e1..d13bc80825b1 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -207,6 +207,7 @@ struct scsi_device {
void *handler_data;
unsigned char access_state;
+ struct mutex state_mutex;
enum scsi_device_state sdev_state;
unsigned long sdev_data[0];
} __attribute__((aligned(sizeof(unsigned long))));
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* Re: [PATCH v3 04/12] Protect SCSI device state changes with a mutex
2017-06-02 21:21 ` [PATCH v3 04/12] Protect SCSI device state changes with a mutex Bart Van Assche
@ 2017-06-05 8:09 ` Christoph Hellwig
2017-06-05 15:18 ` Bart Van Assche
0 siblings, 1 reply; 21+ messages in thread
From: Christoph Hellwig @ 2017-06-05 8:09 UTC (permalink / raw)
To: Bart Van Assche
Cc: Martin K . Petersen, James Bottomley, linux-scsi,
Christoph Hellwig, Hannes Reinecke, Johannes Thumshirn
On Fri, Jun 02, 2017 at 02:21:55PM -0700, Bart Van Assche wrote:
> Serializing SCSI device state changes avoids that two state changes
> can occur concurrently, e.g. the state changes in scsi_target_block()
> and __scsi_remove_device(). This serialization is essential to make
> patch "Make __scsi_remove_device go straight from BLOCKED to DEL"
> work reliably.
>
> Enable this mechanism for all scsi_target_*block() callers but not
> for the scsi_internal_device_unblock() calls from the mpt3sas driver
> because that driver can call scsi_internal_device_unblock() from
> atomic context.
And not taking the lock in that path is safe because of what conditions?
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v3 04/12] Protect SCSI device state changes with a mutex
2017-06-05 8:09 ` Christoph Hellwig
@ 2017-06-05 15:18 ` Bart Van Assche
2017-06-05 18:36 ` Bart Van Assche
0 siblings, 1 reply; 21+ messages in thread
From: Bart Van Assche @ 2017-06-05 15:18 UTC (permalink / raw)
To: hch; +Cc: linux-scsi, James.Bottomley, hare, jthumshirn, martin.petersen
On Mon, 2017-06-05 at 10:09 +0200, Christoph Hellwig wrote:
> On Fri, Jun 02, 2017 at 02:21:55PM -0700, Bart Van Assche wrote:
> > Serializing SCSI device state changes avoids that two state changes
> > can occur concurrently, e.g. the state changes in scsi_target_block()
> > and __scsi_remove_device(). This serialization is essential to make
> > patch "Make __scsi_remove_device go straight from BLOCKED to DEL"
> > work reliably.
> >
> > Enable this mechanism for all scsi_target_*block() callers but not
> > for the scsi_internal_device_unblock() calls from the mpt3sas driver
> > because that driver can call scsi_internal_device_unblock() from
> > atomic context.
>
> And not taking the lock in that path is safe because of what conditions?
Hello Christoph,
The mpt3sas driver is the only driver that calls scsi_internal_device_block()
and scsi_internal_device_unblock() from atomic context. Since it's not an option
to protect the SCSI device state changes with a spinlock I prefer that the
mpt3sas authors convert the scsi_internal_device_block() calls into
scsi_target_block() calls.
Bart.
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v3 04/12] Protect SCSI device state changes with a mutex
2017-06-05 15:18 ` Bart Van Assche
@ 2017-06-05 18:36 ` Bart Van Assche
2017-06-08 15:53 ` hch
0 siblings, 1 reply; 21+ messages in thread
From: Bart Van Assche @ 2017-06-05 18:36 UTC (permalink / raw)
To: hch; +Cc: linux-scsi, James.Bottomley, hare, jthumshirn, martin.petersen
On Mon, 2017-06-05 at 15:18 +0000, Bart Van Assche wrote:
> On Mon, 2017-06-05 at 10:09 +0200, Christoph Hellwig wrote:
> > On Fri, Jun 02, 2017 at 02:21:55PM -0700, Bart Van Assche wrote:
> > > Serializing SCSI device state changes avoids that two state changes
> > > can occur concurrently, e.g. the state changes in scsi_target_block()
> > > and __scsi_remove_device(). This serialization is essential to make
> > > patch "Make __scsi_remove_device go straight from BLOCKED to DEL"
> > > work reliably.
> > >
> > > Enable this mechanism for all scsi_target_*block() callers but not
> > > for the scsi_internal_device_unblock() calls from the mpt3sas driver
> > > because that driver can call scsi_internal_device_unblock() from
> > > atomic context.
> >
> > And not taking the lock in that path is safe because of what conditions?
>
> The mpt3sas driver is the only driver that calls scsi_internal_device_block()
> and scsi_internal_device_unblock() from atomic context. Since it's not an option
> to protect the SCSI device state changes with a spinlock I prefer that the
> mpt3sas authors convert the scsi_internal_device_block() calls into
> scsi_target_block() calls.
Please also note that although this patch series doesn't improve the mpt3sas
driver, it doesn't change its behavior.
Bart.
^ permalink raw reply [flat|nested] 21+ messages in thread
* Re: [PATCH v3 04/12] Protect SCSI device state changes with a mutex
2017-06-05 18:36 ` Bart Van Assche
@ 2017-06-08 15:53 ` hch
0 siblings, 0 replies; 21+ messages in thread
From: hch @ 2017-06-08 15:53 UTC (permalink / raw)
To: Bart Van Assche
Cc: hch, linux-scsi, James.Bottomley, hare, jthumshirn, martin.petersen
On Mon, Jun 05, 2017 at 06:36:19PM +0000, Bart Van Assche wrote:
> > The mpt3sas driver is the only driver that calls scsi_internal_device_block()
> > and scsi_internal_device_unblock() from atomic context. Since it's not an option
> > to protect the SCSI device state changes with a spinlock I prefer that the
> > mpt3sas authors convert the scsi_internal_device_block() calls into
> > scsi_target_block() calls.
>
> Please also note that although this patch series doesn't improve the mpt3sas
> driver, it doesn't change its behavior.
Yes. And normally we try to get things right. I guess this series is
useful enough without fixing everyone up, but adding a FIXME or getting
the broadcom folks involved would be even better.
^ permalink raw reply [flat|nested] 21+ messages in thread
* [PATCH v3 05/12] Introduce scsi_start_queue()
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
` (3 preceding siblings ...)
2017-06-02 21:21 ` [PATCH v3 04/12] Protect SCSI device state changes with a mutex Bart Van Assche
@ 2017-06-02 21:21 ` Bart Van Assche
2017-06-02 21:21 ` [PATCH v3 06/12] Make __scsi_remove_device go straight from BLOCKED to DEL Bart Van Assche
` (8 subsequent siblings)
13 siblings, 0 replies; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:21 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche, Israel Rukshin,
Max Gurtovoy, Benjamin Block
This patch does not change any functionality.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Israel Rukshin <israelr@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Benjamin Block <bblock@linux.vnet.ibm.com>
---
drivers/scsi/scsi_lib.c | 25 +++++++++++++++----------
drivers/scsi/scsi_priv.h | 1 +
2 files changed, 16 insertions(+), 10 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 845d47244e70..6a58a124714f 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -3030,6 +3030,20 @@ static int scsi_internal_device_block(struct scsi_device *sdev)
return err;
}
+void scsi_start_queue(struct scsi_device *sdev)
+{
+ struct request_queue *q = sdev->request_queue;
+ unsigned long flags;
+
+ if (q->mq_ops) {
+ blk_mq_start_stopped_hw_queues(q, false);
+ } else {
+ spin_lock_irqsave(q->queue_lock, flags);
+ blk_start_queue(q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+ }
+}
+
/**
* scsi_internal_device_unblock_nowait - resume a device after a block request
* @sdev: device to resume
@@ -3048,9 +3062,6 @@ static int scsi_internal_device_block(struct scsi_device *sdev)
int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
enum scsi_device_state new_state)
{
- struct request_queue *q = sdev->request_queue;
- unsigned long flags;
-
/*
* Try to transition the scsi device to SDEV_RUNNING or one of the
* offlined states and goose the device queue if successful.
@@ -3068,13 +3079,7 @@ int scsi_internal_device_unblock_nowait(struct scsi_device *sdev,
sdev->sdev_state != SDEV_OFFLINE)
return -EINVAL;
- if (q->mq_ops) {
- blk_mq_start_stopped_hw_queues(q, false);
- } else {
- spin_lock_irqsave(q->queue_lock, flags);
- blk_start_queue(q);
- spin_unlock_irqrestore(q->queue_lock, flags);
- }
+ scsi_start_queue(sdev);
return 0;
}
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index 59ebc1795bb3..f86057842f9a 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -88,6 +88,7 @@ extern void scsi_run_host_queues(struct Scsi_Host *shost);
extern void scsi_requeue_run_queue(struct work_struct *work);
extern struct request_queue *scsi_alloc_queue(struct scsi_device *sdev);
extern struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev);
+extern void scsi_start_queue(struct scsi_device *sdev);
extern int scsi_mq_setup_tags(struct Scsi_Host *shost);
extern void scsi_mq_destroy_tags(struct Scsi_Host *shost);
extern int scsi_init_queue(void);
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 06/12] Make __scsi_remove_device go straight from BLOCKED to DEL
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
` (4 preceding siblings ...)
2017-06-02 21:21 ` [PATCH v3 05/12] Introduce scsi_start_queue() Bart Van Assche
@ 2017-06-02 21:21 ` Bart Van Assche
2017-06-02 21:21 ` [PATCH v3 07/12] Only add commands to the device command list if required by the LLD Bart Van Assche
` (7 subsequent siblings)
13 siblings, 0 replies; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:21 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche, Israel Rukshin,
Max Gurtovoy, Benjamin Block
If a device is blocked, make __scsi_remove_device() cause it to
transition to the DEL state. This means that all the commands
issued in .shutdown() will error in the mid-layer, thus making
the removal proceed without being stopped.
This patch is a slightly modified version of a patch from James
Bottomley. This patch avoids that the following lockup occurs:
Call Trace:
schedule+0x35/0x80
schedule_timeout+0x237/0x2d0
io_schedule_timeout+0xa6/0x110
wait_for_completion_io+0xa3/0x110
blk_execute_rq+0xdf/0x120
scsi_execute+0xce/0x150 [scsi_mod]
scsi_execute_req_flags+0x8f/0xf0 [scsi_mod]
sd_sync_cache+0xa9/0x190 [sd_mod]
sd_shutdown+0x6a/0x100 [sd_mod]
sd_remove+0x64/0xc0 [sd_mod]
__device_release_driver+0x8d/0x120
device_release_driver+0x1e/0x30
bus_remove_device+0xf9/0x170
device_del+0x127/0x240
__scsi_remove_device+0xc1/0xd0 [scsi_mod]
scsi_forget_host+0x57/0x60 [scsi_mod]
scsi_remove_host+0x72/0x110 [scsi_mod]
srp_remove_work+0x8b/0x200 [ib_srp]
Reported-by: Israel Rukshin <israelr@mellanox.com>
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Israel Rukshin <israelr@mellanox.com>
Cc: Max Gurtovoy <maxg@mellanox.com>
Cc: Benjamin Block <bblock@linux.vnet.ibm.com>
---
drivers/scsi/scsi_lib.c | 2 +-
drivers/scsi/scsi_sysfs.c | 10 ++++++++++
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 6a58a124714f..8665eccd2fc8 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2624,7 +2624,6 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
case SDEV_QUIESCE:
case SDEV_OFFLINE:
case SDEV_TRANSPORT_OFFLINE:
- case SDEV_BLOCK:
break;
default:
goto illegal;
@@ -2638,6 +2637,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
case SDEV_OFFLINE:
case SDEV_TRANSPORT_OFFLINE:
case SDEV_CANCEL:
+ case SDEV_BLOCK:
case SDEV_CREATED_BLOCK:
break;
default:
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index a91537a3abbf..ce470f62a8ae 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1290,7 +1290,17 @@ void __scsi_remove_device(struct scsi_device *sdev)
* wait until it has finished before changing the device state.
*/
mutex_lock(&sdev->state_mutex);
+ /*
+ * If blocked, we go straight to DEL and restart the queue so
+ * any commands issued during driver shutdown (like sync
+ * cache) are errored immediately.
+ */
res = scsi_device_set_state(sdev, SDEV_CANCEL);
+ if (res != 0) {
+ res = scsi_device_set_state(sdev, SDEV_DEL);
+ if (res == 0)
+ scsi_start_queue(sdev);
+ }
mutex_unlock(&sdev->state_mutex);
if (res != 0)
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 07/12] Only add commands to the device command list if required by the LLD
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
` (5 preceding siblings ...)
2017-06-02 21:21 ` [PATCH v3 06/12] Make __scsi_remove_device go straight from BLOCKED to DEL Bart Van Assche
@ 2017-06-02 21:21 ` Bart Van Assche
2017-06-02 21:21 ` [PATCH v3 08/12] Introduce scsi_mq_sgl_size() Bart Van Assche
` (6 subsequent siblings)
13 siblings, 0 replies; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:21 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche, Johannes Thumshirn
Just like for the scsi-mq code path, in the single queue SCSI code
path only add commands to the per-device command list if required
by the SCSI LLD. This patch will make it easier to merge the
single-queue and multiqueue command initialization code.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
---
drivers/scsi/scsi.c | 9 +--------
drivers/scsi/scsi_lib.c | 52 +++++++++++++++++++++++++++++-------------------
drivers/scsi/scsi_priv.h | 2 ++
3 files changed, 35 insertions(+), 28 deletions(-)
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 7bfbcfa7af40..485684aafb9b 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -108,14 +108,7 @@ EXPORT_SYMBOL(scsi_sd_pm_domain);
*/
void scsi_put_command(struct scsi_cmnd *cmd)
{
- unsigned long flags;
-
- /* serious error if the command hasn't come from a device list */
- spin_lock_irqsave(&cmd->device->list_lock, flags);
- BUG_ON(list_empty(&cmd->list));
- list_del_init(&cmd->list);
- spin_unlock_irqrestore(&cmd->device->list_lock, flags);
-
+ scsi_del_cmd_from_list(cmd);
BUG_ON(delayed_work_pending(&cmd->abort_work));
}
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 8665eccd2fc8..2c43b500e9f4 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -583,19 +583,9 @@ static void scsi_mq_free_sgtables(struct scsi_cmnd *cmd)
static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
{
- struct scsi_device *sdev = cmd->device;
- struct Scsi_Host *shost = sdev->host;
- unsigned long flags;
-
scsi_mq_free_sgtables(cmd);
scsi_uninit_cmd(cmd);
-
- if (shost->use_cmd_list) {
- BUG_ON(list_empty(&cmd->list));
- spin_lock_irqsave(&sdev->list_lock, flags);
- list_del_init(&cmd->list);
- spin_unlock_irqrestore(&sdev->list_lock, flags);
- }
+ scsi_del_cmd_from_list(cmd);
}
/*
@@ -1133,12 +1123,40 @@ int scsi_init_io(struct scsi_cmnd *cmd)
}
EXPORT_SYMBOL(scsi_init_io);
+/* Add a command to the list used by the aacraid and dpt_i2o drivers */
+void scsi_add_cmd_to_list(struct scsi_cmnd *cmd)
+{
+ struct scsi_device *sdev = cmd->device;
+ struct Scsi_Host *shost = sdev->host;
+ unsigned long flags;
+
+ if (shost->use_cmd_list) {
+ spin_lock_irqsave(&sdev->list_lock, flags);
+ list_add_tail(&cmd->list, &sdev->cmd_list);
+ spin_unlock_irqrestore(&sdev->list_lock, flags);
+ }
+}
+
+/* Remove a command from the list used by the aacraid and dpt_i2o drivers */
+void scsi_del_cmd_from_list(struct scsi_cmnd *cmd)
+{
+ struct scsi_device *sdev = cmd->device;
+ struct Scsi_Host *shost = sdev->host;
+ unsigned long flags;
+
+ if (shost->use_cmd_list) {
+ spin_lock_irqsave(&sdev->list_lock, flags);
+ BUG_ON(list_empty(&cmd->list));
+ list_del_init(&cmd->list);
+ spin_unlock_irqrestore(&sdev->list_lock, flags);
+ }
+}
+
void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
{
void *buf = cmd->sense_buffer;
void *prot = cmd->prot_sdb;
unsigned int unchecked_isa_dma = cmd->flags & SCMD_UNCHECKED_ISA_DMA;
- unsigned long flags;
/* zero out the cmd, except for the embedded scsi_request */
memset((char *)cmd + sizeof(cmd->req), 0,
@@ -1151,9 +1169,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
cmd->jiffies_at_alloc = jiffies;
- spin_lock_irqsave(&dev->list_lock, flags);
- list_add_tail(&cmd->list, &dev->cmd_list);
- spin_unlock_irqrestore(&dev->list_lock, flags);
+ scsi_add_cmd_to_list(cmd);
}
static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req)
@@ -1870,11 +1886,7 @@ static int scsi_mq_prep_fn(struct request *req)
INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
cmd->jiffies_at_alloc = jiffies;
- if (shost->use_cmd_list) {
- spin_lock_irq(&sdev->list_lock);
- list_add_tail(&cmd->list, &sdev->cmd_list);
- spin_unlock_irq(&sdev->list_lock);
- }
+ scsi_add_cmd_to_list(cmd);
sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
cmd->sdb.table.sgl = sg;
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index f86057842f9a..c11c1f9c912c 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -80,6 +80,8 @@ int scsi_eh_get_sense(struct list_head *work_q,
int scsi_noretry_cmd(struct scsi_cmnd *scmd);
/* scsi_lib.c */
+extern void scsi_add_cmd_to_list(struct scsi_cmnd *cmd);
+extern void scsi_del_cmd_from_list(struct scsi_cmnd *cmd);
extern int scsi_maybe_unblock_host(struct scsi_device *sdev);
extern void scsi_device_unbusy(struct scsi_device *sdev);
extern void scsi_queue_insert(struct scsi_cmnd *cmd, int reason);
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 08/12] Introduce scsi_mq_sgl_size()
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
` (6 preceding siblings ...)
2017-06-02 21:21 ` [PATCH v3 07/12] Only add commands to the device command list if required by the LLD Bart Van Assche
@ 2017-06-02 21:21 ` Bart Van Assche
2017-06-02 21:22 ` [PATCH v3 09/12] Make scsi_mq_prep_fn() call scsi_init_command() Bart Van Assche
` (5 subsequent siblings)
13 siblings, 0 replies; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:21 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche, Hannes Reinecke,
Johannes Thumshirn
This patch does not change any functionality but makes the next
patch easier to read.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
---
drivers/scsi/scsi_lib.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 2c43b500e9f4..6b4fb48033fb 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1858,6 +1858,13 @@ static inline int prep_to_mq(int ret)
}
}
+/* Size in bytes of the sg-list stored in the scsi-mq command-private data. */
+static unsigned int scsi_mq_sgl_size(struct Scsi_Host *shost)
+{
+ return min_t(unsigned int, shost->sg_tablesize, SG_CHUNK_SIZE) *
+ sizeof(struct scatterlist);
+}
+
static int scsi_mq_prep_fn(struct request *req)
{
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
@@ -1892,10 +1899,7 @@ static int scsi_mq_prep_fn(struct request *req)
cmd->sdb.table.sgl = sg;
if (scsi_host_get_prot(shost)) {
- cmd->prot_sdb = (void *)sg +
- min_t(unsigned int,
- shost->sg_tablesize, SG_CHUNK_SIZE) *
- sizeof(struct scatterlist);
+ cmd->prot_sdb = (void *)sg + scsi_mq_sgl_size(shost);
memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer));
cmd->prot_sdb->table.sgl =
@@ -2201,12 +2205,9 @@ struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev)
int scsi_mq_setup_tags(struct Scsi_Host *shost)
{
- unsigned int cmd_size, sgl_size, tbl_size;
+ unsigned int cmd_size, sgl_size;
- tbl_size = shost->sg_tablesize;
- if (tbl_size > SG_CHUNK_SIZE)
- tbl_size = SG_CHUNK_SIZE;
- sgl_size = tbl_size * sizeof(struct scatterlist);
+ sgl_size = scsi_mq_sgl_size(shost);
cmd_size = sizeof(struct scsi_cmnd) + shost->hostt->cmd_size + sgl_size;
if (scsi_host_get_prot(shost))
cmd_size += sizeof(struct scsi_data_buffer) + sgl_size;
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 09/12] Make scsi_mq_prep_fn() call scsi_init_command()
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
` (7 preceding siblings ...)
2017-06-02 21:21 ` [PATCH v3 08/12] Introduce scsi_mq_sgl_size() Bart Van Assche
@ 2017-06-02 21:22 ` Bart Van Assche
2017-06-05 8:10 ` Christoph Hellwig
2017-06-02 21:22 ` [PATCH v3 10/12] snic: Remove code that zeroes driver-private command data Bart Van Assche
` (4 subsequent siblings)
13 siblings, 1 reply; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:22 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche, Hannes Reinecke,
Johannes Thumshirn
This patch reduces code duplication. There are two functional changes
in this patch:
- It causes scsi_mq_prep_fn() to clear driver-private
command data, just like the already upstream commit 1bad6c4a57ef
("scsi: zero per-cmd private driver data for each MQ I/O").
- The initialization of .prot_sdb is moved from scsi_mq_prep_fn()
into scsi_init_request().
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
---
drivers/scsi/scsi_lib.c | 25 +++++++++----------------
1 file changed, 9 insertions(+), 16 deletions(-)
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 6b4fb48033fb..ef4e33319407 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1870,36 +1870,21 @@ static int scsi_mq_prep_fn(struct request *req)
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
struct scsi_device *sdev = req->q->queuedata;
struct Scsi_Host *shost = sdev->host;
- unsigned char *sense_buf = cmd->sense_buffer;
- unsigned int unchecked_isa_dma = cmd->flags & SCMD_UNCHECKED_ISA_DMA;
struct scatterlist *sg;
- /* zero out the cmd, except for the embedded scsi_request */
- memset((char *)cmd + sizeof(cmd->req), 0,
- sizeof(*cmd) - sizeof(cmd->req));
+ scsi_init_command(sdev, cmd);
req->special = cmd;
cmd->request = req;
- cmd->device = sdev;
- cmd->sense_buffer = sense_buf;
- cmd->flags = unchecked_isa_dma;
cmd->tag = req->tag;
-
cmd->prot_op = SCSI_PROT_NORMAL;
- INIT_LIST_HEAD(&cmd->list);
- INIT_DELAYED_WORK(&cmd->abort_work, scmd_eh_abort_handler);
- cmd->jiffies_at_alloc = jiffies;
-
- scsi_add_cmd_to_list(cmd);
-
sg = (void *)cmd + sizeof(struct scsi_cmnd) + shost->hostt->cmd_size;
cmd->sdb.table.sgl = sg;
if (scsi_host_get_prot(shost)) {
- cmd->prot_sdb = (void *)sg + scsi_mq_sgl_size(shost);
memset(cmd->prot_sdb, 0, sizeof(struct scsi_data_buffer));
cmd->prot_sdb->table.sgl =
@@ -2025,6 +2010,7 @@ static int scsi_init_request(struct blk_mq_tag_set *set, struct request *rq,
struct Scsi_Host *shost = set->driver_data;
const bool unchecked_isa_dma = shost->unchecked_isa_dma;
struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(rq);
+ struct scatterlist *sg;
if (unchecked_isa_dma)
cmd->flags |= SCMD_UNCHECKED_ISA_DMA;
@@ -2033,6 +2019,13 @@ static int scsi_init_request(struct blk_mq_tag_set *set, struct request *rq,
if (!cmd->sense_buffer)
return -ENOMEM;
cmd->req.sense = cmd->sense_buffer;
+
+ if (scsi_host_get_prot(shost)) {
+ sg = (void *)cmd + sizeof(struct scsi_cmnd) +
+ shost->hostt->cmd_size;
+ cmd->prot_sdb = (void *)sg + scsi_mq_sgl_size(shost);
+ }
+
return 0;
}
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 10/12] snic: Remove code that zeroes driver-private command data
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
` (8 preceding siblings ...)
2017-06-02 21:22 ` [PATCH v3 09/12] Make scsi_mq_prep_fn() call scsi_init_command() Bart Van Assche
@ 2017-06-02 21:22 ` Bart Van Assche
2017-06-02 21:22 ` [PATCH v3 11/12] virtio_scsi: " Bart Van Assche
` (3 subsequent siblings)
13 siblings, 0 replies; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:22 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche, Sesidhar Baddela,
Johannes Thumshirn
Since the SCSI core zeroes driver-private command data, remove
that code from the snic driver.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Narsimhulu Musini <nmusini@cisco.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Sesidhar Baddela <sebaddel@cisco.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
---
drivers/scsi/snic/snic_scsi.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/scsi/snic/snic_scsi.c b/drivers/scsi/snic/snic_scsi.c
index da979a73baa0..05c3a7282d4a 100644
--- a/drivers/scsi/snic/snic_scsi.c
+++ b/drivers/scsi/snic/snic_scsi.c
@@ -359,8 +359,6 @@ snic_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *sc)
SNIC_SCSI_DBG(shost, "sc %p Tag %d (sc %0x) lun %lld in snic_qcmd\n",
sc, snic_cmd_tag(sc), sc->cmnd[0], sc->device->lun);
- memset(scsi_cmd_priv(sc), 0, sizeof(struct snic_internal_io_state));
-
ret = snic_issue_scsi_req(snic, tgt, sc);
if (ret) {
SNIC_HOST_ERR(shost, "Failed to Q, Scsi Req w/ err %d.\n", ret);
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 11/12] virtio_scsi: Remove code that zeroes driver-private command data
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
` (9 preceding siblings ...)
2017-06-02 21:22 ` [PATCH v3 10/12] snic: Remove code that zeroes driver-private command data Bart Van Assche
@ 2017-06-02 21:22 ` Bart Van Assche
2017-06-02 21:22 ` [PATCH v3 12/12] xen/scsifront: " Bart Van Assche
` (2 subsequent siblings)
13 siblings, 0 replies; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:22 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche,
Michael S . Tsirkin, Johannes Thumshirn
Since the SCSI core zeroes driver-private command data, remove
that code from the virtio driver.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
---
drivers/scsi/virtio_scsi.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index f8dbfeee6c63..dc2e97c543a5 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -547,7 +547,6 @@ static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
dev_dbg(&sc->device->sdev_gendev,
"cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
- memset(cmd, 0, sizeof(*cmd));
cmd->sc = sc;
BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 12/12] xen/scsifront: Remove code that zeroes driver-private command data
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
` (10 preceding siblings ...)
2017-06-02 21:22 ` [PATCH v3 11/12] virtio_scsi: " Bart Van Assche
@ 2017-06-02 21:22 ` Bart Van Assche
2017-06-02 21:22 ` Bart Van Assche
2017-06-13 1:04 ` [PATCH v3 00/12] SCSI patches for kernel v4.13 Martin K. Petersen
13 siblings, 0 replies; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:22 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: Bart Van Assche, Johannes Thumshirn, Christoph Hellwig,
linux-scsi, xen-devel
Since the SCSI core zeroes driver-private command data, remove
that code from the xen-scsifront driver.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: xen-devel@lists.xenproject.org
Cc: Johannes Thumshirn <jthumshirn@suse.de>
---
drivers/scsi/xen-scsifront.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
index a6a8b60d4902..36f59a1be7e9 100644
--- a/drivers/scsi/xen-scsifront.c
+++ b/drivers/scsi/xen-scsifront.c
@@ -534,7 +534,6 @@ static int scsifront_queuecommand(struct Scsi_Host *shost,
int err;
sc->result = 0;
- memset(shadow, 0, sizeof(*shadow));
shadow->sc = sc;
shadow->act = VSCSIIF_ACT_SCSI_CDB;
--
2.12.2
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
https://lists.xen.org/xen-devel
^ permalink raw reply related [flat|nested] 21+ messages in thread
* [PATCH v3 12/12] xen/scsifront: Remove code that zeroes driver-private command data
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
` (11 preceding siblings ...)
2017-06-02 21:22 ` [PATCH v3 12/12] xen/scsifront: " Bart Van Assche
@ 2017-06-02 21:22 ` Bart Van Assche
2017-06-13 1:04 ` [PATCH v3 00/12] SCSI patches for kernel v4.13 Martin K. Petersen
13 siblings, 0 replies; 21+ messages in thread
From: Bart Van Assche @ 2017-06-02 21:22 UTC (permalink / raw)
To: Martin K . Petersen, James Bottomley
Cc: linux-scsi, Christoph Hellwig, Bart Van Assche, xen-devel,
Johannes Thumshirn
Since the SCSI core zeroes driver-private command data, remove
that code from the xen-scsifront driver.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: xen-devel@lists.xenproject.org
Cc: Johannes Thumshirn <jthumshirn@suse.de>
---
drivers/scsi/xen-scsifront.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/scsi/xen-scsifront.c b/drivers/scsi/xen-scsifront.c
index a6a8b60d4902..36f59a1be7e9 100644
--- a/drivers/scsi/xen-scsifront.c
+++ b/drivers/scsi/xen-scsifront.c
@@ -534,7 +534,6 @@ static int scsifront_queuecommand(struct Scsi_Host *shost,
int err;
sc->result = 0;
- memset(shadow, 0, sizeof(*shadow));
shadow->sc = sc;
shadow->act = VSCSIIF_ACT_SCSI_CDB;
--
2.12.2
^ permalink raw reply related [flat|nested] 21+ messages in thread
* Re: [PATCH v3 00/12] SCSI patches for kernel v4.13
2017-06-02 21:21 [PATCH v3 00/12] SCSI patches for kernel v4.13 Bart Van Assche
` (12 preceding siblings ...)
2017-06-02 21:22 ` Bart Van Assche
@ 2017-06-13 1:04 ` Martin K. Petersen
13 siblings, 0 replies; 21+ messages in thread
From: Martin K. Petersen @ 2017-06-13 1:04 UTC (permalink / raw)
To: Bart Van Assche
Cc: Martin K . Petersen, James Bottomley, linux-scsi, Christoph Hellwig
Bart,
> This patch series consists of the bug fixes and improvements I came up
> with during the past two months. This patch series has been developed
> on top of your 4.13/scsi-queue branch. Please consider these patches
> for kernel v4.13.
Applied to 4.13/scsi-queue, thanks!
--
Martin K. Petersen Oracle Linux Engineering
^ permalink raw reply [flat|nested] 21+ messages in thread