From edabf036a27d8825db130cf97f70fadf9f0fbad9 Mon Sep 17 00:00:00 2001
From: mav <mav@FreeBSD.org>
Date: Mon, 3 Nov 2014 03:45:41 +0000
Subject: [PATCH] MFC r273809: Implement better handling for ENOSPC error for
 both CTL and CAM.

This makes VMWare VAAI Thin Provisioning Stun primitive activate, pausing
the virtual machine, when backing storage (ZFS pool) is getting overflowed.
---
 sys/cam/ctl/ctl_backend_block.c | 17 ++++++++++-------
 sys/cam/ctl/ctl_error.c         | 12 ++++++++++++
 sys/cam/ctl/ctl_error.h         |  1 +
 sys/cam/scsi/scsi_all.c         |  2 +-
 4 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/sys/cam/ctl/ctl_backend_block.c b/sys/cam/ctl/ctl_backend_block.c
index 9ea8b9489e51..e6122a3ddccd 100644
--- a/sys/cam/ctl/ctl_backend_block.c
+++ b/sys/cam/ctl/ctl_backend_block.c
@@ -504,6 +504,8 @@ ctl_be_block_biodone(struct bio *bio)
 	if (beio->num_errors > 0) {
 		if (error == EOPNOTSUPP) {
 			ctl_set_invalid_opcode(&io->scsiio);
+		} else if (error == ENOSPC) {
+			ctl_set_space_alloc_fail(&io->scsiio);
 		} else if (beio->bio_cmd == BIO_FLUSH) {
 			/* XXX KDM is there is a better error here? */
 			ctl_set_internal_failure(&io->scsiio,
@@ -714,14 +716,12 @@ ctl_be_block_dispatch_file(struct ctl_be_block_lun *be_lun,
 		char path_str[32];
 
 		ctl_scsi_path_string(io, path_str, sizeof(path_str));
-		/*
-		 * XXX KDM ZFS returns ENOSPC when the underlying
-		 * filesystem fills up.  What kind of SCSI error should we
-		 * return for that?
-		 */
 		printf("%s%s command returned errno %d\n", path_str,
 		       (beio->bio_cmd == BIO_READ) ? "READ" : "WRITE", error);
-		ctl_set_medium_error(&io->scsiio);
+		if (error == ENOSPC) {
+			ctl_set_space_alloc_fail(&io->scsiio);
+		} else
+			ctl_set_medium_error(&io->scsiio);
 		ctl_complete_beio(beio);
 		return;
 	}
@@ -807,7 +807,10 @@ ctl_be_block_dispatch_zvol(struct ctl_be_block_lun *be_lun,
 	 * return the I/O to the user.
 	 */
 	if (error != 0) {
-		ctl_set_medium_error(&io->scsiio);
+		if (error == ENOSPC) {
+			ctl_set_space_alloc_fail(&io->scsiio);
+		} else
+			ctl_set_medium_error(&io->scsiio);
 		ctl_complete_beio(beio);
 		return;
 	}
diff --git a/sys/cam/ctl/ctl_error.c b/sys/cam/ctl/ctl_error.c
index d2edb2a95712..b6a8b89d1332 100644
--- a/sys/cam/ctl/ctl_error.c
+++ b/sys/cam/ctl/ctl_error.c
@@ -805,6 +805,18 @@ ctl_set_task_aborted(struct ctl_scsiio *ctsio)
 	ctsio->io_hdr.status = CTL_CMD_ABORTED;
 }
 
+void
+ctl_set_space_alloc_fail(struct ctl_scsiio *ctsio)
+{
+	/* "Space allocation failed write protect" */
+	ctl_set_sense(ctsio,
+		      /*current_error*/ 1,
+		      /*sense_key*/ SSD_KEY_DATA_PROTECT,
+		      /*asc*/ 0x27,
+		      /*ascq*/ 0x07,
+		      SSD_ELEM_NONE);
+}
+
 void
 ctl_set_success(struct ctl_scsiio *ctsio)
 {
diff --git a/sys/cam/ctl/ctl_error.h b/sys/cam/ctl/ctl_error.h
index 034d14bff990..d7d82aa392a0 100644
--- a/sys/cam/ctl/ctl_error.h
+++ b/sys/cam/ctl/ctl_error.h
@@ -81,6 +81,7 @@ void ctl_set_reservation_conflict(struct ctl_scsiio *ctsio);
 void ctl_set_queue_full(struct ctl_scsiio *ctsio);
 void ctl_set_busy(struct ctl_scsiio *ctsio);
 void ctl_set_task_aborted(struct ctl_scsiio *ctsio);
+void ctl_set_space_alloc_fail(struct ctl_scsiio *ctsio);
 void ctl_set_success(struct ctl_scsiio *ctsio);
 
 #endif	/* _CTL_ERROR_H_ */
diff --git a/sys/cam/scsi/scsi_all.c b/sys/cam/scsi/scsi_all.c
index cef2c51f8892..4e0dcd341d93 100644
--- a/sys/cam/scsi/scsi_all.c
+++ b/sys/cam/scsi/scsi_all.c
@@ -1733,7 +1733,7 @@ static struct asc_table_entry asc_table[] = {
 	{ SST(0x27, 0x06, SS_RDEF,	/* XXX TBD */
 	    "Conditional write protect") },
 	/* D         B    */
-	{ SST(0x27, 0x07, SS_RDEF,	/* XXX TBD */
+	{ SST(0x27, 0x07, SS_FATAL | ENOSPC,
 	    "Space allocation failed write protect") },
 	/* DTLPWROMAEBKVF */
 	{ SST(0x28, 0x00, SS_FATAL | ENXIO,