5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Bart Van Assche bvanassche@acm.org
[ Upstream commit bf23e619039d360d503b7282d030daf2277a5d47 ]
Conditional statements are faster than indirect calls. Use a structure member to track the SCSI command submitter such that later patches can call scsi_done(scmd) instead of scmd->scsi_done(scmd).
The asymmetric behavior that scsi_send_eh_cmnd() sets the submission context to the SCSI error handler and that it does not restore the submission context to the SCSI core is retained.
Link: https://lore.kernel.org/r/20211007202923.2174984-2-bvanassche@acm.org Cc: Hannes Reinecke hare@suse.com Cc: Ming Lei ming.lei@redhat.com Cc: Christoph Hellwig hch@lst.de Reviewed-by: Benjamin Block bblock@linux.ibm.com Reviewed-by: Bean Huo beanhuo@micron.com Signed-off-by: Bart Van Assche bvanassche@acm.org Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Stable-dep-of: e193b7955dfa ("RDMA/srp: Do not call scsi_done() from srp_abort()") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/scsi_error.c | 17 ++++++----------- drivers/scsi/scsi_lib.c | 10 ++++++++++ drivers/scsi/scsi_priv.h | 1 + include/scsi/scsi_cmnd.h | 7 +++++++ 4 files changed, 24 insertions(+), 11 deletions(-)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c index dd9f5778f687d..18b99240a9062 100644 --- a/drivers/scsi/scsi_error.c +++ b/drivers/scsi/scsi_error.c @@ -50,8 +50,6 @@
#include <asm/unaligned.h>
-static void scsi_eh_done(struct scsi_cmnd *scmd); - /* * These should *probably* be handled by the host itself. * Since it is allowed to sleep, it probably should. @@ -542,7 +540,8 @@ enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd) /* handler does not care. Drop down to default handling */ }
- if (scmd->cmnd[0] == TEST_UNIT_READY && scmd->scsi_done != scsi_eh_done) + if (scmd->cmnd[0] == TEST_UNIT_READY && + scmd->submitter != SUBMITTED_BY_SCSI_ERROR_HANDLER) /* * nasty: for mid-layer issued TURs, we need to return the * actual sense data without any recovery attempt. For eh @@ -804,7 +803,7 @@ static enum scsi_disposition scsi_eh_completed_normally(struct scsi_cmnd *scmd) * scsi_eh_done - Completion function for error handling. * @scmd: Cmd that is done. */ -static void scsi_eh_done(struct scsi_cmnd *scmd) +void scsi_eh_done(struct scsi_cmnd *scmd) { struct completion *eh_action;
@@ -1104,7 +1103,7 @@ static enum scsi_disposition scsi_send_eh_cmnd(struct scsi_cmnd *scmd, shost->eh_action = &done;
scsi_log_send(scmd); - scmd->scsi_done = scsi_eh_done; + scmd->submitter = SUBMITTED_BY_SCSI_ERROR_HANDLER;
/* * Lock sdev->state_mutex to avoid that scsi_device_quiesce() can @@ -1131,6 +1130,7 @@ static enum scsi_disposition scsi_send_eh_cmnd(struct scsi_cmnd *scmd, if (rtn) { if (timeleft > stall_for) { scsi_eh_restore_cmnd(scmd, &ses); + timeleft -= stall_for; msleep(jiffies_to_msecs(stall_for)); goto retry; @@ -2360,11 +2360,6 @@ void scsi_report_device_reset(struct Scsi_Host *shost, int channel, int target) } EXPORT_SYMBOL(scsi_report_device_reset);
-static void -scsi_reset_provider_done_command(struct scsi_cmnd *scmd) -{ -} - /** * scsi_ioctl_reset: explicitly reset a host/bus/target/device * @dev: scsi_device to operate on @@ -2401,7 +2396,7 @@ scsi_ioctl_reset(struct scsi_device *dev, int __user *arg) scsi_init_command(dev, scmd); scmd->cmnd = scsi_req(rq)->cmd;
- scmd->scsi_done = scsi_reset_provider_done_command; + scmd->submitter = SUBMITTED_BY_SCSI_RESET_IOCTL; memset(&scmd->sdb, 0, sizeof(scmd->sdb));
scmd->cmd_len = 0; diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 5525e6ffee537..7bdaa6b757cd4 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1578,6 +1578,15 @@ static blk_status_t scsi_prepare_cmd(struct request *req)
static void scsi_mq_done(struct scsi_cmnd *cmd) { + switch (cmd->submitter) { + case SUBMITTED_BY_BLOCK_LAYER: + break; + case SUBMITTED_BY_SCSI_ERROR_HANDLER: + return scsi_eh_done(cmd); + case SUBMITTED_BY_SCSI_RESET_IOCTL: + return; + } + if (unlikely(blk_should_fake_timeout(scsi_cmd_to_rq(cmd)->q))) return; if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state))) @@ -1684,6 +1693,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
scsi_set_resid(cmd, 0); memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); + cmd->submitter = SUBMITTED_BY_BLOCK_LAYER; cmd->scsi_done = scsi_mq_done;
blk_mq_start_request(req); diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index 6d9152031a403..b7f9631493522 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -84,6 +84,7 @@ void scsi_eh_ready_devs(struct Scsi_Host *shost, int scsi_eh_get_sense(struct list_head *work_q, struct list_head *done_q); int scsi_noretry_cmd(struct scsi_cmnd *scmd); +void scsi_eh_done(struct scsi_cmnd *scmd);
/* scsi_lib.c */ extern int scsi_maybe_unblock_host(struct scsi_device *sdev); diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h index 685249233f2fe..0823bad7b0c90 100644 --- a/include/scsi/scsi_cmnd.h +++ b/include/scsi/scsi_cmnd.h @@ -65,6 +65,12 @@ struct scsi_pointer { #define SCMD_STATE_COMPLETE 0 #define SCMD_STATE_INFLIGHT 1
+enum scsi_cmnd_submitter { + SUBMITTED_BY_BLOCK_LAYER = 0, + SUBMITTED_BY_SCSI_ERROR_HANDLER = 1, + SUBMITTED_BY_SCSI_RESET_IOCTL = 2, +} __packed; + struct scsi_cmnd { struct scsi_request req; struct scsi_device *device; @@ -90,6 +96,7 @@ struct scsi_cmnd { unsigned char prot_op; unsigned char prot_type; unsigned char prot_flags; + enum scsi_cmnd_submitter submitter;
unsigned short cmd_len; enum dma_data_direction sc_data_direction;