[stgt] Problem with dvd burner

[FUJITA Tomonori]

On Thu, 21 Apr 2011 21:22:12 +0200
Frank Michel <michelfranck at neuf.fr> wrote:

> This a timeout problem :
> - Editing  the "tgt-1.0.15/usr/bs_sg.c"
> - Setting the "#define BS_SG_TIMEOUT" from 2000 to (30 * 1000) cleared
> the problem
> 
> As advertised in a previous patch which didn't make its way to the
> 1.0.15 release, this timeout should be adapted to the type of
> peripheral which is matching the generic sg device. For example, it
> should be longer for a tape reader.
> 
> Is there a chance that the timeout patch be merged in the next or so release ?

I forgot to apply the patch. I don't like it much since it's a
workaround. But I applied it for now.


=
From: FUJITA Tomonori <fujita.tomonori at lab.ntt.co.jp>
Subject: [PATCH] use longer timeout for sg

This adds a workaround to use longer timeout for sg. We should use
appropriate timeout for each device type.

Signed-off-by: FUJITA Tomonori <fujita.tomonori at lab.ntt.co.jp>
Tested-by: Mark Harvey <markh794 at gmail.com>
---
 usr/bs_sg.c |   47 ++++++++++++++++++++++++++++++++++++++++++++---
 1 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/usr/bs_sg.c b/usr/bs_sg.c
index 01c998a..c4c9ca0 100644
--- a/usr/bs_sg.c
+++ b/usr/bs_sg.c
@@ -46,7 +46,8 @@
 #include "tgtadm_error.h"
 
 #define BS_SG_RESVD_SZ  (512 * 1024)
-#define BS_SG_TIMEOUT	2000
+
+static unsigned int sg_timeout = 30 * 1000; /* 30 seconds */
 
 static int graceful_read(int fd, void *p_read, int to_read)
 {
@@ -149,7 +150,7 @@ static int bs_bsg_cmd_submit(struct scsi_cmd *cmd)
 	/* SCSI: (auto)sense data */
 	io_hdr.response = (unsigned long)cmd->sense_buffer;
 	/* Using the same 2000 millisecond timeout.. */
-	io_hdr.timeout = BS_SG_TIMEOUT;
+	io_hdr.timeout = sg_timeout;
 	/* [i->o] unused internally */
 	io_hdr.usr_ptr = (unsigned long)cmd;
 	dprintf("[%d] Set io_hdr->usr_ptr from cmd: %p\n", getpid(), cmd);
@@ -168,6 +169,29 @@ static int bs_bsg_cmd_submit(struct scsi_cmd *cmd)
 	return 0;
 }
 
+static void bs_sg_cmd_setup(struct sg_io_hdr *hdr,
+			   unsigned char *cmd, int cmd_len,
+			   void *data, int data_len, int direction,
+			   void *sense, int sense_len,
+			   int timeout)
+{
+	memset(hdr, 0, sizeof(*hdr));
+	hdr->interface_id = 'S';
+	hdr->cmdp = cmd;
+	hdr->cmd_len = cmd_len;
+
+	hdr->dxfer_direction = direction;
+	hdr->dxfer_len = data_len;
+	hdr->dxferp = data;
+
+	hdr->mx_sb_len = sense_len;
+	hdr->sbp = sense;
+	hdr->timeout = timeout;
+	hdr->pack_id = -1;
+	hdr->usr_ptr = NULL;
+	hdr->flags = 0;
+}
+
 static int bs_sg_cmd_submit(struct scsi_cmd *cmd)
 {
 	struct scsi_lu *dev = cmd->dev;
@@ -191,7 +215,7 @@ static int bs_sg_cmd_submit(struct scsi_cmd *cmd)
 	}
 	io_hdr.mx_sb_len = sizeof(cmd->sense_buffer);
 	io_hdr.sbp = cmd->sense_buffer;
-	io_hdr.timeout = BS_SG_TIMEOUT;
+	io_hdr.timeout = sg_timeout;
 	io_hdr.pack_id = -1;
 	io_hdr.usr_ptr = cmd;
 	io_hdr.flags |= SG_FLAG_DIRECT_IO;
@@ -344,6 +368,9 @@ static int init_bsg_device(int fd)
 static int init_sg_device(int fd)
 {
 	int t, err;
+	struct sg_io_hdr hdr;
+	unsigned char cmd[6];
+	unsigned char resp[36];
 
 	err = ioctl(fd, SG_GET_VERSION_NUM, &t);
 	if ((err < 0) || (t < 30000)) {
@@ -358,6 +385,20 @@ static int init_sg_device(int fd)
 		return -1;
 	}
 
+	memset(&cmd, 0, sizeof(cmd));
+	memset(&resp, 0, sizeof(resp));
+
+	cmd[0] = INQUIRY;
+	cmd[4] = sizeof(resp);
+
+	bs_sg_cmd_setup(&hdr, cmd, sizeof(cmd), resp, sizeof(resp),
+			SG_DXFER_FROM_DEV, NULL, 0, 30000);
+
+	err = ioctl(fd, SG_IO, &hdr);
+
+	if (!err && (resp[0] & 0x1f) == TYPE_TAPE)
+		sg_timeout = 14000 * 1000;
+
 	return 0;
 }
 
-- 
1.7.2.3

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