Merge patch series "scsi: fixes for targets with many LUNs, and scsi_target_block rework"

Martin Wilck <mwilck@suse.com> says:

This patch series addresses some issues we saw in a test setup with a
large number of SCSI LUNs. The first two patches simply increase the
number of available sg and bsg devices. 3-5 fix a large delay we
encountered between blocking a Fibre Channel remote port and the
dev_loss_tmo. 6 renames scsi_target_block() to scsi_block_targets(),
and makes additional changes to this API, as suggested in the review
of the v2 series. 7 improves a warning message.

Link: https://lore.kernel.org/r/20230614103616.31857-1-mwilck@suse.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Martin K. Petersen 2023-06-16 12:21:04 -04:00
commit af92c02fb2
8 changed files with 50 additions and 49 deletions

View File

@ -36,7 +36,7 @@ static inline struct bsg_device *to_bsg_device(struct inode *inode)
}
#define BSG_DEFAULT_CMDS 64
#define BSG_MAX_DEVS 32768
#define BSG_MAX_DEVS (1 << MINORBITS)
static DEFINE_IDA(bsg_minor_ida);
static struct class *bsg_class;

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@ -2731,24 +2731,16 @@ void scsi_start_queue(struct scsi_device *sdev)
blk_mq_unquiesce_queue(sdev->request_queue);
}
static void scsi_stop_queue(struct scsi_device *sdev, bool nowait)
static void scsi_stop_queue(struct scsi_device *sdev)
{
/*
* The atomic variable of ->queue_stopped covers that
* blk_mq_quiesce_queue* is balanced with blk_mq_unquiesce_queue.
*
* However, we still need to wait until quiesce is done
* in case that queue has been stopped.
* The caller needs to wait until quiesce is done.
*/
if (!cmpxchg(&sdev->queue_stopped, 0, 1)) {
if (nowait)
if (!cmpxchg(&sdev->queue_stopped, 0, 1))
blk_mq_quiesce_queue_nowait(sdev->request_queue);
else
blk_mq_quiesce_queue(sdev->request_queue);
} else {
if (!nowait)
blk_mq_wait_quiesce_done(sdev->request_queue->tag_set);
}
}
/**
@ -2775,19 +2767,19 @@ int scsi_internal_device_block_nowait(struct scsi_device *sdev)
* request queue.
*/
if (!ret)
scsi_stop_queue(sdev, true);
scsi_stop_queue(sdev);
return ret;
}
EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
/**
* scsi_internal_device_block - try to transition to the SDEV_BLOCK state
* scsi_device_block - try to transition to the SDEV_BLOCK state
* @sdev: device to block
* @data: dummy argument, ignored
*
* 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.
* Pause SCSI command processing on the specified device. Callers must wait
* until all ongoing scsi_queue_rq() calls have finished after this function
* returns.
*
* Note:
* This routine transitions the device to the SDEV_BLOCK state (which must be
@ -2795,17 +2787,26 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_block_nowait);
* is paused until the device leaves the SDEV_BLOCK state. See also
* scsi_internal_device_unblock().
*/
static int scsi_internal_device_block(struct scsi_device *sdev)
static void scsi_device_block(struct scsi_device *sdev, void *data)
{
int err;
enum scsi_device_state state;
mutex_lock(&sdev->state_mutex);
err = __scsi_internal_device_block_nowait(sdev);
state = sdev->sdev_state;
if (err == 0)
scsi_stop_queue(sdev, false);
/*
* scsi_stop_queue() must be called with the state_mutex
* held. Otherwise a simultaneous scsi_start_queue() call
* might unquiesce the queue before we quiesce it.
*/
scsi_stop_queue(sdev);
mutex_unlock(&sdev->state_mutex);
return err;
WARN_ONCE(err, "%s: failed to block %s in state %d\n",
__func__, dev_name(&sdev->sdev_gendev), state);
}
/**
@ -2888,36 +2889,35 @@ static int scsi_internal_device_unblock(struct scsi_device *sdev,
return ret;
}
static void
device_block(struct scsi_device *sdev, void *data)
{
int ret;
ret = scsi_internal_device_block(sdev);
WARN_ONCE(ret, "scsi_internal_device_block(%s) failed: ret = %d\n",
dev_name(&sdev->sdev_gendev), ret);
}
static int
target_block(struct device *dev, void *data)
{
if (scsi_is_target_device(dev))
starget_for_each_device(to_scsi_target(dev), NULL,
device_block);
scsi_device_block);
return 0;
}
/**
* scsi_block_targets - transition all SCSI child devices to SDEV_BLOCK state
* @dev: a parent device of one or more scsi_target devices
* @shost: the Scsi_Host to which this device belongs
*
* Iterate over all children of @dev, which should be scsi_target devices,
* and switch all subordinate scsi devices to SDEV_BLOCK state. Wait for
* ongoing scsi_queue_rq() calls to finish. May sleep.
*
* Note:
* @dev must not itself be a scsi_target device.
*/
void
scsi_target_block(struct device *dev)
scsi_block_targets(struct Scsi_Host *shost, struct device *dev)
{
if (scsi_is_target_device(dev))
starget_for_each_device(to_scsi_target(dev), NULL,
device_block);
else
WARN_ON_ONCE(scsi_is_target_device(dev));
device_for_each_child(dev, NULL, target_block);
blk_mq_wait_quiesce_done(&shost->tag_set);
}
EXPORT_SYMBOL_GPL(scsi_target_block);
EXPORT_SYMBOL_GPL(scsi_block_targets);
static void
device_unblock(struct scsi_device *sdev, void *data)

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@ -3451,7 +3451,7 @@ fc_remote_port_delete(struct fc_rport *rport)
spin_unlock_irqrestore(shost->host_lock, flags);
scsi_target_block(&rport->dev);
scsi_block_targets(shost, &rport->dev);
/* see if we need to kill io faster than waiting for device loss */
if ((rport->fast_io_fail_tmo != -1) &&

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@ -1943,13 +1943,14 @@ static void __iscsi_block_session(struct work_struct *work)
struct iscsi_cls_session *session =
container_of(work, struct iscsi_cls_session,
block_work);
struct Scsi_Host *shost = iscsi_session_to_shost(session);
unsigned long flags;
ISCSI_DBG_TRANS_SESSION(session, "Blocking session\n");
spin_lock_irqsave(&session->lock, flags);
session->state = ISCSI_SESSION_FAILED;
spin_unlock_irqrestore(&session->lock, flags);
scsi_target_block(&session->dev);
scsi_block_targets(shost, &session->dev);
ISCSI_DBG_TRANS_SESSION(session, "Completed SCSI target blocking\n");
if (session->recovery_tmo >= 0)
queue_delayed_work(session->workq,

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@ -396,7 +396,7 @@ static void srp_reconnect_work(struct work_struct *work)
}
/*
* scsi_target_block() must have been called before this function is
* scsi_block_targets() must have been called before this function is
* called to guarantee that no .queuecommand() calls are in progress.
*/
static void __rport_fail_io_fast(struct srp_rport *rport)
@ -480,7 +480,7 @@ static void __srp_start_tl_fail_timers(struct srp_rport *rport)
srp_rport_set_state(rport, SRP_RPORT_BLOCKED) == 0) {
pr_debug("%s new state: %d\n", dev_name(&shost->shost_gendev),
rport->state);
scsi_target_block(&shost->shost_gendev);
scsi_block_targets(shost, &shost->shost_gendev);
if (fast_io_fail_tmo >= 0)
queue_delayed_work(system_long_wq,
&rport->fast_io_fail_work,
@ -548,7 +548,7 @@ int srp_reconnect_rport(struct srp_rport *rport)
* later is ok though, scsi_internal_device_unblock_nowait()
* treats SDEV_TRANSPORT_OFFLINE like SDEV_BLOCK.
*/
scsi_target_block(&shost->shost_gendev);
scsi_block_targets(shost, &shost->shost_gendev);
res = rport->state != SRP_RPORT_LOST ? i->f->reconnect(rport) : -ENODEV;
pr_debug("%s (state %d): transport.reconnect() returned %d\n",
dev_name(&shost->shost_gendev), rport->state, res);

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@ -71,7 +71,7 @@ static int sg_proc_init(void);
#define SG_ALLOW_DIO_DEF 0
#define SG_MAX_DEVS 32768
#define SG_MAX_DEVS (1 << MINORBITS)
/* SG_MAX_CDB_SIZE should be 260 (spc4r37 section 3.1.30) however the type
* of sg_io_hdr::cmd_len can only represent 255. All SCSI commands greater

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@ -214,7 +214,7 @@ snic_tgt_del(struct work_struct *work)
scsi_flush_work(shost);
/* Block IOs on child devices, stops new IOs */
scsi_target_block(&tgt->dev);
scsi_block_targets(shost, &tgt->dev);
/* Cleanup IOs */
snic_tgt_scsi_abort_io(tgt);

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@ -456,7 +456,7 @@ extern void scsi_scan_target(struct device *parent, unsigned int channel,
unsigned int id, u64 lun,
enum scsi_scan_mode rescan);
extern void scsi_target_reap(struct scsi_target *);
extern void scsi_target_block(struct device *);
void scsi_block_targets(struct Scsi_Host *shost, struct device *dev);
extern void scsi_target_unblock(struct device *, enum scsi_device_state);
extern void scsi_remove_target(struct device *);
extern const char *scsi_device_state_name(enum scsi_device_state);