[PATCH 5/6] libata: Honor RQF_QUIET flag

[Damien Le Moal <damien.lemoal@xxxxxxx>]

Currently, libata ignores requests RQF_QUIET flag and print error
messages for failed commands, regardless if this flag is set in the
command request. Fix this by introducing the ata_eh_quiet() function and
using this function in ata_eh_link_autopsy() to determine if the EH
context should be quiet. This works by counting the number of failed
commands and the number of commands with the quiet flag set. If both
numbers are equal, the the EH context can be set to quiet and all error
messages suppressed. Otherwise, only the error messages for the failed
commands are suppressed and the link Emask and irq_stat messages printed.

Signed-off-by: Damien Le Moal <damien.lemoal@xxxxxxx>
---
 drivers/ata/libata-eh.c   | 26 +++++++++++++++++++++++++-
 drivers/ata/libata-scsi.c |  3 +++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 006ea1507dcf..c9f0c8660a7b 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -2156,6 +2156,21 @@ static inline int ata_eh_worth_retry(struct ata_queued_cmd *qc)
 	return qc->err_mask != AC_ERR_DEV;  /* retry if not dev error */
 }
 
+/**
+ *      ata_eh_quiet - check if we need to be quiet about a command error
+ *      @qc: qc to check
+ *
+ *      Look at the qc flags anbd its scsi command request flags to determine
+ *      if we need to be quiet about the command failure.
+ */
+static inline bool ata_eh_quiet(struct ata_queued_cmd *qc)
+{
+	if (qc->scsicmd &&
+	    qc->scsicmd->request->rq_flags & RQF_QUIET)
+		qc->flags |= ATA_QCFLAG_QUIET;
+	return qc->flags & ATA_QCFLAG_QUIET;
+}
+
 /**
  *	ata_eh_link_autopsy - analyze error and determine recovery action
  *	@link: host link to perform autopsy on
@@ -2173,7 +2188,7 @@ static void ata_eh_link_autopsy(struct ata_link *link)
 	struct ata_eh_context *ehc = &link->eh_context;
 	struct ata_device *dev;
 	unsigned int all_err_mask = 0, eflags = 0;
-	int tag;
+	int tag, nr_failed = 0, nr_quiet = 0;
 	u32 serror;
 	int rc;
 
@@ -2239,8 +2254,17 @@ static void ata_eh_link_autopsy(struct ata_link *link)
 		if (qc->flags & ATA_QCFLAG_IO)
 			eflags |= ATA_EFLAG_IS_IO;
 		trace_ata_eh_link_autopsy_qc(qc);
+
+		/* Count quiet errors */
+		if (ata_eh_quiet(qc))
+			nr_quiet++;
+		nr_failed++;
 	}
 
+	/* If all failed commands requested silence, then be quiet */
+	if (nr_quiet == nr_failed)
+		ehc->i.flags |= ATA_EHI_QUIET;
+
 	/* enforce default EH actions */
 	if (ap->pflags & ATA_PFLAG_FROZEN ||
 	    all_err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT))
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 66be961c93a4..84b6fc8906a2 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -872,6 +872,9 @@ static struct ata_queued_cmd *ata_scsi_qc_new(struct ata_device *dev,
 
 		qc->sg = scsi_sglist(cmd);
 		qc->n_elem = scsi_sg_count(cmd);
+
+		if (cmd->request->rq_flags & RQF_QUIET)
+			qc->flags |= ATA_QCFLAG_QUIET;
 	} else {
 		cmd->result = (DID_OK << 16) | (QUEUE_FULL << 1);
 		cmd->scsi_done(cmd);
-- 
2.14.3