Hides the xarray based lookup of a target given the channel and target
identifiers within a shost. Use this and __sstarg_for_each_device()
where useful.
Break the pattern when deleting to jump back and restart the iteration
as that seems to be a linked list quirk. May change semantics if
elements can be added in the newly created holes in the xarray at the
same time as the ongoing deletion.
Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
---
drivers/scsi/scsi.c | 24 ++++++++++++++++++++++++
drivers/scsi/scsi_error.c | 34 +++++++++++++++++-----------------
drivers/scsi/scsi_lib.c | 8 +++-----
drivers/scsi/scsi_scan.c | 4 ++--
drivers/scsi/scsi_sysfs.c | 8 +++-----
include/scsi/scsi_device.h | 2 ++
6 files changed, 51 insertions(+), 29 deletions(-)
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 9e7658aebdb7..1b1fc8d4e5c2 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -667,6 +667,30 @@ struct scsi_device *__scsi_target_iterate_devices(struct scsi_target *starg,
}
EXPORT_SYMBOL(__scsi_target_iterate_devices);
+/**
+ * __scsi_target_lookup - helper to find target given channel and target_id
+ * @shost: host to search within
+ * @chan: channel number
+ * @t_id: target identifier
+ *
+ * No locks or references taken. Returns NULL if not found.
+ */
+struct scsi_target *__scsi_target_lookup(struct Scsi_Host *shost,
+ uint chan, uint t_id)
+{
+ unsigned long l_idx;
+ struct scsi_target *starg = NULL;
+
+ if (shost) {
+ xa_for_each(&shost->__targets, l_idx, starg) {
+ if (chan == starg->channel && t_id == starg->id)
+ break;
+ }
+ }
+ return starg;
+}
+EXPORT_SYMBOL(__scsi_target_lookup);
+
/**
* starget_for_each_device - helper to walk all devices of a target
* @starg: target whose devices we want to iterate over.
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 978be1602f71..b2dbfa5f73a0 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -644,6 +644,7 @@ static void scsi_handle_queue_ramp_up(struct scsi_device *sdev)
{
struct scsi_host_template *sht = sdev->host->hostt;
struct scsi_device *tmp_sdev;
+ struct scsi_target *starg = scsi_target(sdev);
if (!sht->track_queue_depth ||
sdev->queue_depth >= sdev->max_queue_depth)
@@ -658,13 +659,10 @@ static void scsi_handle_queue_ramp_up(struct scsi_device *sdev)
return;
/*
- * Walk all devices of a target and do
- * ramp up on them.
+ * Walk all devices of a target and do ramp up on them.
*/
- shost_for_each_device(tmp_sdev, sdev->host) {
- if (tmp_sdev->channel != sdev->channel ||
- tmp_sdev->id != sdev->id ||
- tmp_sdev->queue_depth == sdev->max_queue_depth)
+ sstarg_for_each_device(tmp_sdev, starg) {
+ if (tmp_sdev->queue_depth == sdev->max_queue_depth)
continue;
scsi_change_queue_depth(tmp_sdev, tmp_sdev->queue_depth + 1);
@@ -672,25 +670,26 @@ static void scsi_handle_queue_ramp_up(struct scsi_device *sdev)
}
}
+/*
+ * queue_full corresponds to the SCSI status: "Task Set Full". Its scope is
+ * at the SCSI taret device level.
+ */
static void scsi_handle_queue_full(struct scsi_device *sdev)
{
struct scsi_host_template *sht = sdev->host->hostt;
struct scsi_device *tmp_sdev;
+ struct scsi_target *starg = scsi_target(sdev);
if (!sht->track_queue_depth)
return;
- shost_for_each_device(tmp_sdev, sdev->host) {
- if (tmp_sdev->channel != sdev->channel ||
- tmp_sdev->id != sdev->id)
- continue;
+ sstarg_for_each_device(tmp_sdev, starg)
/*
* We do not know the number of commands that were at
- * the device when we got the queue full so we start
+ * the target when we got the queue full so we start
* from the highest possible value and work our way down.
*/
scsi_track_queue_full(tmp_sdev, tmp_sdev->queue_depth - 1);
- }
}
/**
@@ -2305,12 +2304,13 @@ EXPORT_SYMBOL(scsi_report_bus_reset);
void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target)
{
struct scsi_device *sdev;
+ struct scsi_target *starg = __scsi_target_lookup(shost, channel,
+ target);
- __shost_for_each_device(sdev, shost) {
- if (channel == sdev_channel(sdev) &&
- target == sdev_id(sdev))
- __scsi_report_device_reset(sdev, NULL);
- }
+ if (!starg)
+ return;
+ __sstarg_for_each_device(sdev, starg)
+ __scsi_report_device_reset(sdev, NULL);
}
EXPORT_SYMBOL(scsi_report_device_reset);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index f484bf2b5d7d..034ec2e57d1c 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -374,7 +374,7 @@ static void scsi_single_lun_run(struct scsi_device *current_sdev)
struct Scsi_Host *shost = current_sdev->host;
struct scsi_device *sdev;
struct scsi_target *starget = scsi_target(current_sdev);
- unsigned long flags, l_idx;
+ unsigned long flags;
spin_lock_irqsave(shost->host_lock, flags);
starget->starget_sdev_user = NULL;
@@ -392,7 +392,7 @@ static void scsi_single_lun_run(struct scsi_device *current_sdev)
if (starget->starget_sdev_user)
goto out;
/* XARRAY: was list_for_each_entry_safe(); is this safe ? */
- xa_for_each(&starget->devices, l_idx, sdev) {
+ __sstarg_for_each_device(sdev, starget) {
if (sdev == current_sdev)
continue;
if (scsi_device_get(sdev))
@@ -2217,14 +2217,12 @@ scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
}
EXPORT_SYMBOL(scsi_test_unit_ready);
-/* Assume host_lock taken and that xahp->xa_lock is the same lock. */
static inline void
scsi_adjust_non_sdev_del_mark(struct scsi_device *sdev,
enum scsi_device_state old_state,
enum scsi_device_state new_state)
{
- struct xarray *xatp =
- &to_scsi_target(sdev->sdev_gendev.parent)->devices;
+ struct xarray *xatp = &scsi_target(sdev)->devices;
struct xarray *xahp = &sdev->host->__devices;
if (old_state == new_state)
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index f5a5e48ca5ae..c055ee083ea9 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1880,13 +1880,13 @@ void scsi_forget_host(struct Scsi_Host *shost)
struct scsi_device *sdev;
unsigned long flags, l_idx;
- restart:
spin_lock_irqsave(shost->host_lock, flags);
xa_for_each_marked(&shost->__devices, l_idx, sdev,
SCSI_XA_NON_SDEV_DEL) {
spin_unlock_irqrestore(shost->host_lock, flags);
__scsi_remove_device(sdev);
- goto restart;
+ /* XARRAY: was a goto to before first line */
+ spin_lock_irqsave(shost->host_lock, flags);
}
spin_unlock_irqrestore(shost->host_lock, flags);
}
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 6fdd4648f374..394230d69afd 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -1480,7 +1480,6 @@ static void __scsi_remove_target(struct scsi_target *starget)
unsigned long flags, l_idx;
spin_lock_irqsave(shost->host_lock, flags);
- restart:
xa_for_each_marked(&starget->devices, l_idx, sdev,
SCSI_XA_NON_SDEV_DEL) {
/*
@@ -1496,8 +1495,7 @@ static void __scsi_remove_target(struct scsi_target *starget)
scsi_remove_device(sdev);
put_device(&sdev->sdev_gendev);
spin_lock_irqsave(shost->host_lock, flags);
- /* XARRAY: is this goto start of loop correct ? */
- goto restart;
+ /* XARRAY: was a goto to restart loop */
}
spin_unlock_irqrestore(shost->host_lock, flags);
}
@@ -1516,7 +1514,6 @@ void scsi_remove_target(struct device *dev)
struct scsi_target *starget;
unsigned long flags, l_idx;
-restart:
spin_lock_irqsave(shost->host_lock, flags);
xa_for_each(&shost->__targets, l_idx, starget) {
if (starget->state == STARGET_DEL ||
@@ -1532,7 +1529,8 @@ void scsi_remove_target(struct device *dev)
spin_unlock_irqrestore(shost->host_lock, flags);
__scsi_remove_target(starget);
scsi_target_reap(starget);
- goto restart;
+ /* XARRAY: was a goto to before first line */
+ spin_lock_irqsave(shost->host_lock, flags);
}
}
spin_unlock_irqrestore(shost->host_lock, flags);
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 23bf686cbabc..e019621416d5 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -362,6 +362,8 @@ extern struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *,
u64);
extern struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *,
u64);
+extern struct scsi_target *__scsi_target_lookup(struct Scsi_Host *shost,
+ uint chan, uint t_id);
/* XARRAY: these visitor names too close to sstarg_for_each_device macros? */
extern void starget_for_each_device(struct scsi_target *, void *,
void (*fn)(struct scsi_device *, void *));
--
2.25.1
