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authorIngo Molnar <mingo@kernel.org>2012-08-21 11:27:00 +0200
committerIngo Molnar <mingo@kernel.org>2012-08-21 11:27:00 +0200
commitbcada3d4b8c96b8792c2306f363992ca5ab9da42 (patch)
treee420679a5db6ea4e1694eef57f9abb6acac8d4d3 /drivers/scsi/scsi_lib.c
parent26198c21d1b286a084fe5d514a30bc7e6c712a34 (diff)
parent000078bc3ee69efb1124b8478c7527389a826074 (diff)
Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: * Fix include order for bison/flex-generated C files, from Ben Hutchings * Build fixes and documentation corrections from David Ahern * Group parsing support, from Jiri Olsa * UI/gtk refactorings and improvements from Namhyung Kim * NULL deref fix for perf script, from Namhyung Kim * Assorted cleanups from Robert Richter * Let O= makes handle relative paths, from Steven Rostedt * perf script python fixes, from Feng Tang. * Improve 'perf lock' error message when the needed tracepoints are not present, from David Ahern. * Initial bash completion support, from Frederic Weisbecker * Allow building without libelf, from Namhyung Kim. * Support DWARF CFI based unwind to have callchains when %bp based unwinding is not possible, from Jiri Olsa. * Symbol resolution fixes, while fixing support PPC64 files with an .opt ELF section was the end goal, several fixes for code that handles all architectures and cleanups are included, from Cody Schafer. * Add a description for the JIT interface, from Andi Kleen. * Assorted fixes for Documentation and build in 32 bit, from Robert Richter * Add support for non-tracepoint events in perf script python, from Feng Tang * Cache the libtraceevent event_format associated to each evsel early, so that we avoid relookups, i.e. calling pevent_find_event repeatedly when processing tracepoint events. [ This is to reduce the surface contact with libtraceevents and make clear what is that the perf tools needs from that lib: so far parsing the common and per event fields. ] Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c121
1 files changed, 67 insertions, 54 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 6dfb9785d34..ffd77739ae3 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -68,6 +68,23 @@ static struct scsi_host_sg_pool scsi_sg_pools[] = {
struct kmem_cache *scsi_sdb_cache;
+#ifdef CONFIG_ACPI
+#include <acpi/acpi_bus.h>
+
+int scsi_register_acpi_bus_type(struct acpi_bus_type *bus)
+{
+ bus->bus = &scsi_bus_type;
+ return register_acpi_bus_type(bus);
+}
+EXPORT_SYMBOL_GPL(scsi_register_acpi_bus_type);
+
+void scsi_unregister_acpi_bus_type(struct acpi_bus_type *bus)
+{
+ unregister_acpi_bus_type(bus);
+}
+EXPORT_SYMBOL_GPL(scsi_unregister_acpi_bus_type);
+#endif
+
/*
* When to reinvoke queueing after a resource shortage. It's 3 msecs to
* not change behaviour from the previous unplug mechanism, experimentation
@@ -109,7 +126,7 @@ static void scsi_unprep_request(struct request *req)
* for a requeue after completion, which should only occur in this
* file.
*/
-static int __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
+static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
{
struct Scsi_Host *host = cmd->device->host;
struct scsi_device *device = cmd->device;
@@ -155,15 +172,14 @@ static int __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
/*
* Requeue this command. It will go before all other commands
- * that are already in the queue.
+ * that are already in the queue. Schedule requeue work under
+ * lock such that the kblockd_schedule_work() call happens
+ * before blk_cleanup_queue() finishes.
*/
spin_lock_irqsave(q->queue_lock, flags);
blk_requeue_request(q, cmd->request);
- spin_unlock_irqrestore(q->queue_lock, flags);
-
kblockd_schedule_work(q, &device->requeue_work);
-
- return 0;
+ spin_unlock_irqrestore(q->queue_lock, flags);
}
/*
@@ -185,9 +201,9 @@ static int __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy)
* Notes: This could be called either from an interrupt context or a
* normal process context.
*/
-int scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
+void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
{
- return __scsi_queue_insert(cmd, reason, 1);
+ __scsi_queue_insert(cmd, reason, 1);
}
/**
* scsi_execute - insert request and wait for the result
@@ -406,10 +422,6 @@ static void scsi_run_queue(struct request_queue *q)
LIST_HEAD(starved_list);
unsigned long flags;
- /* if the device is dead, sdev will be NULL, so no queue to run */
- if (!sdev)
- return;
-
shost = sdev->host;
if (scsi_target(sdev)->single_lun)
scsi_single_lun_run(sdev);
@@ -483,15 +495,26 @@ void scsi_requeue_run_queue(struct work_struct *work)
*/
static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd)
{
+ struct scsi_device *sdev = cmd->device;
struct request *req = cmd->request;
unsigned long flags;
+ /*
+ * We need to hold a reference on the device to avoid the queue being
+ * killed after the unlock and before scsi_run_queue is invoked which
+ * may happen because scsi_unprep_request() puts the command which
+ * releases its reference on the device.
+ */
+ get_device(&sdev->sdev_gendev);
+
spin_lock_irqsave(q->queue_lock, flags);
scsi_unprep_request(req);
blk_requeue_request(q, req);
spin_unlock_irqrestore(q->queue_lock, flags);
scsi_run_queue(q);
+
+ put_device(&sdev->sdev_gendev);
}
void scsi_next_command(struct scsi_cmnd *cmd)
@@ -1173,6 +1196,7 @@ int scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
switch (sdev->sdev_state) {
case SDEV_OFFLINE:
+ case SDEV_TRANSPORT_OFFLINE:
/*
* If the device is offline we refuse to process any
* commands. The device must be brought online
@@ -1370,16 +1394,16 @@ static inline int scsi_host_queue_ready(struct request_queue *q,
* may be changed after request stacking drivers call the function,
* regardless of taking lock or not.
*
- * When scsi can't dispatch I/Os anymore and needs to kill I/Os
- * (e.g. !sdev), scsi needs to return 'not busy'.
- * Otherwise, request stacking drivers may hold requests forever.
+ * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi
+ * needs to return 'not busy'. Otherwise, request stacking drivers
+ * may hold requests forever.
*/
static int scsi_lld_busy(struct request_queue *q)
{
struct scsi_device *sdev = q->queuedata;
struct Scsi_Host *shost;
- if (!sdev)
+ if (blk_queue_dead(q))
return 0;
shost = sdev->host;
@@ -1490,12 +1514,6 @@ static void scsi_request_fn(struct request_queue *q)
struct scsi_cmnd *cmd;
struct request *req;
- if (!sdev) {
- while ((req = blk_peek_request(q)) != NULL)
- scsi_kill_request(req, q);
- return;
- }
-
if(!get_device(&sdev->sdev_gendev))
/* We must be tearing the block queue down already */
return;
@@ -1697,20 +1715,6 @@ struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
return q;
}
-void scsi_free_queue(struct request_queue *q)
-{
- unsigned long flags;
-
- WARN_ON(q->queuedata);
-
- /* cause scsi_request_fn() to kill all non-finished requests */
- spin_lock_irqsave(q->queue_lock, flags);
- q->request_fn(q);
- spin_unlock_irqrestore(q->queue_lock, flags);
-
- blk_cleanup_queue(q);
-}
-
/*
* Function: scsi_block_requests()
*
@@ -2081,6 +2085,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
switch (oldstate) {
case SDEV_CREATED:
case SDEV_OFFLINE:
+ case SDEV_TRANSPORT_OFFLINE:
case SDEV_QUIESCE:
case SDEV_BLOCK:
break;
@@ -2093,6 +2098,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
switch (oldstate) {
case SDEV_RUNNING:
case SDEV_OFFLINE:
+ case SDEV_TRANSPORT_OFFLINE:
break;
default:
goto illegal;
@@ -2100,6 +2106,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
break;
case SDEV_OFFLINE:
+ case SDEV_TRANSPORT_OFFLINE:
switch (oldstate) {
case SDEV_CREATED:
case SDEV_RUNNING:
@@ -2136,6 +2143,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
case SDEV_RUNNING:
case SDEV_QUIESCE:
case SDEV_OFFLINE:
+ case SDEV_TRANSPORT_OFFLINE:
case SDEV_BLOCK:
break;
default:
@@ -2148,6 +2156,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
case SDEV_CREATED:
case SDEV_RUNNING:
case SDEV_OFFLINE:
+ case SDEV_TRANSPORT_OFFLINE:
case SDEV_CANCEL:
break;
default:
@@ -2405,7 +2414,6 @@ EXPORT_SYMBOL(scsi_target_resume);
* (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.
- * This routine assumes the host_lock is held on entry.
*/
int
scsi_internal_device_block(struct scsi_device *sdev)
@@ -2438,6 +2446,7 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_block);
/**
* scsi_internal_device_unblock - resume a device after a block request
* @sdev: device to resume
+ * @new_state: state to set devices 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
@@ -2447,25 +2456,29 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_block);
*
* Notes:
* This routine transitions the device to the SDEV_RUNNING state
- * (which must be a legal transition) allowing the midlayer to
- * goose the queue for this device. This routine assumes the
- * host_lock is held upon entry.
+ * 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)
+scsi_internal_device_unblock(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
- * and goose the device queue if successful.
+
+ /*
+ * Try to transition the scsi device to SDEV_RUNNING or one of the
+ * offlined states and goose the device queue if successful.
*/
if (sdev->sdev_state == SDEV_BLOCK)
- sdev->sdev_state = SDEV_RUNNING;
- else if (sdev->sdev_state == SDEV_CREATED_BLOCK)
- sdev->sdev_state = SDEV_CREATED;
- else if (sdev->sdev_state != SDEV_CANCEL &&
+ sdev->sdev_state = new_state;
+ else if (sdev->sdev_state == SDEV_CREATED_BLOCK) {
+ if (new_state == SDEV_TRANSPORT_OFFLINE ||
+ new_state == SDEV_OFFLINE)
+ sdev->sdev_state = new_state;
+ else
+ sdev->sdev_state = SDEV_CREATED;
+ } else if (sdev->sdev_state != SDEV_CANCEL &&
sdev->sdev_state != SDEV_OFFLINE)
return -EINVAL;
@@ -2506,26 +2519,26 @@ EXPORT_SYMBOL_GPL(scsi_target_block);
static void
device_unblock(struct scsi_device *sdev, void *data)
{
- scsi_internal_device_unblock(sdev);
+ scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data);
}
static int
target_unblock(struct device *dev, void *data)
{
if (scsi_is_target_device(dev))
- starget_for_each_device(to_scsi_target(dev), NULL,
+ starget_for_each_device(to_scsi_target(dev), data,
device_unblock);
return 0;
}
void
-scsi_target_unblock(struct device *dev)
+scsi_target_unblock(struct device *dev, enum scsi_device_state new_state)
{
if (scsi_is_target_device(dev))
- starget_for_each_device(to_scsi_target(dev), NULL,
+ starget_for_each_device(to_scsi_target(dev), &new_state,
device_unblock);
else
- device_for_each_child(dev, NULL, target_unblock);
+ device_for_each_child(dev, &new_state, target_unblock);
}
EXPORT_SYMBOL_GPL(scsi_target_unblock);