[stgt] [PATCH] 1/1 Honour media capacity

[Mark Harvey]

>From 8838e603da133001d3284f0ee1f0a6c71f906d09 Mon Sep 17 00:00:00 2001
From: Mark Harvey <markh794 at gmail.com>
Date: Tue, 13 Oct 2009 18:36:15 +1100
Subject: Honour media capacity.

Return NO_SENSE with 'EOM' set once 'media capacity' number of bytes
written to backing store file.

Signed-off-by: Mark Harvey <markh794 at gmail.com>
---
 usr/bs_ssc.c |   23 +++++++++++++++++++++--
 1 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/usr/bs_ssc.c b/usr/bs_ssc.c
index ce5c3bf..b2ad7c7 100644
--- a/usr/bs_ssc.c
+++ b/usr/bs_ssc.c
@@ -40,6 +40,12 @@
 #include "ssc.h"
 #include "libssc.h"
 
+#define SENSE_FILEMARK	0x80
+#define SENSE_EOM	0x40
+#define SENSE_ILI	0X20
+
+static uint64_t media_capacity;
+
 static void ssc_sense_data_build(struct scsi_cmd *cmd, uint8_t key,
 				 uint16_t asc, uint8_t *info, int info_len)
 {
@@ -109,6 +115,12 @@ static int resp_rewind(struct scsi_lu *lu)
 	return skip_next_header(lu);
 }
 
+static unsigned long current_size(struct scsi_cmd *cmd)
+{
+	struct ssc_info *ssc = dtype_priv(cmd->dev);
+	return ssc->c_blk.curr;
+}
+
 static int append_blk(struct scsi_cmd *cmd, uint8_t *data,
 		      int size, int orig_sz, int type)
 {
@@ -184,8 +196,6 @@ static int append_blk(struct scsi_cmd *cmd, uint8_t *data,
 	return SAM_STAT_GOOD;
 }
 
-#define SENSE_FILEMARK 0x80
-
 static int space_filemark_reverse(struct scsi_cmd *cmd, int32_t count)
 {
 	struct ssc_info *ssc = dtype_priv(cmd->dev);
@@ -515,6 +525,14 @@ static void tape_rdwr_request(struct scsi_cmd *cmd)
 			count, length, ret, (fixed) ? "Yes" : "No",
 			block_length);
 
+		/* Check for end of media */
+		if (current_size(cmd) > media_capacity) {
+			sense_data_build(cmd, NO_SENSE|SENSE_EOM,
+						NO_ADDITIONAL_SENSE);
+			result = SAM_STAT_CHECK_CONDITION;
+			break;
+		}
+
 		if (ret != length) {
 			sense_data_build(cmd, MEDIUM_ERROR, ASC_WRITE_ERROR);
 			result = SAM_STAT_CHECK_CONDITION;
@@ -630,6 +648,7 @@ static int bs_ssc_open(struct scsi_lu *lu, char *path, int *fd, uint64_t *size)
 		eprintf("Failed to read MAM: %d %m\n", (int)rd);
 		return -1;
 	}
+	media_capacity = ssc->mam.max_capacity;
 
 	rd = ssc_read_blkhdr(*fd, h, h->next);
 	if (rd) {
-- 
1.6.0.4



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