ata_id: Support SG_IO version 4 interface

This makes it possible to use /dev/bsg/* nodes for ata_id:

 # /lib/udev/ata_id --export /dev/bsg/0\:0\:0\:0
 ID_ATA=1
 ID_TYPE=disk
 ID_BUS=ata
 ID_MODEL=INTEL_SSDSA2MH080G1GC
 ID_MODEL_ENC=INTEL\x20SSDSA2MH080G1GC\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20
 ID_REVISION=045C8802
 [...]

This means that our cd-rom detection as per commit

 http://git.kernel.org/?p=linux/hotplug/udev.git;a=commit;h=160b069c25690bfb0c785994c7c3710289179107

needs to be reworked since we can't just use the CDROM_GET_CAPABILITY
ioctl on a /dev/bsg node (which is a character device). We do this by
just sending the SCSI INQUIRY command and checking the type (CD-ROM's
are all type 0x05 and disks are type 0x00) before we issue the ATA
IDENTIFY command through the SCSI command ATA PASS_THROUGH (12).

 (Yes, it's a bit perverse how we have to tunnel our ATA commands
 through a SCSI command  but that's how Linux currently work.)

We still support for SG_IO version 3 (we fail back if version 4 fails
with EINVAL) because testing reveals that some drivers (such as
mpt2sas) still only support version 3 on the block nodes.

Signed-off-by: David Zeuthen <davidz@redhat.com>
This commit is contained in:
David Zeuthen 2010-10-30 11:44:06 -04:00
parent d43e5e5b5a
commit 6992637e31

View file

@ -3,7 +3,7 @@
*
* Copyright (C) 2005-2008 Kay Sievers <kay.sievers@vrfy.org>
* Copyright (C) 2009 Lennart Poettering <lennart@poettering.net>
* Copyright (C) 2009 David Zeuthen <zeuthen@gmail.com>
* Copyright (C) 2009-2010 David Zeuthen <zeuthen@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@ -39,85 +39,166 @@
#include <linux/hdreg.h>
#include <linux/fs.h>
#include <linux/cdrom.h>
#include <linux/bsg.h>
#include <arpa/inet.h>
#include "libudev.h"
#include "libudev-private.h"
#define COMMAND_TIMEOUT 2000
#define COMMAND_TIMEOUT_MSEC (30 * 1000)
/* Sends a SCSI command block */
static int sg_io(int fd, int direction,
const void *cdb, size_t cdb_len,
void *data, size_t data_len,
void *sense, size_t sense_len)
static int disk_scsi_inquiry_command(int fd,
void *buf,
size_t buf_len)
{
struct sg_io_v4 io_v4;
uint8_t cdb[12];
uint8_t sense[32];
int ret;
struct sg_io_hdr io_hdr;
/*
* INQUIRY, see SPC-4 section 6.4
*/
memset(cdb, 0, sizeof(cdb));
cdb[0] = 0x12; /* OPERATION CODE: INQUIRY */
cdb[3] = (buf_len >> 8); /* ALLOCATION LENGTH */
cdb[4] = (buf_len & 0xff);
memset(&io_hdr, 0, sizeof(struct sg_io_hdr));
io_hdr.interface_id = 'S';
io_hdr.cmdp = (unsigned char*) cdb;
io_hdr.cmd_len = cdb_len;
io_hdr.dxferp = data;
io_hdr.dxfer_len = data_len;
io_hdr.sbp = sense;
io_hdr.mx_sb_len = sense_len;
io_hdr.dxfer_direction = direction;
io_hdr.timeout = COMMAND_TIMEOUT;
return ioctl(fd, SG_IO, &io_hdr);
memset(sense, 0, sizeof(sense));
memset(&io_v4, 0, sizeof(struct sg_io_v4));
io_v4.guard = 'Q';
io_v4.protocol = BSG_PROTOCOL_SCSI;
io_v4.subprotocol = BSG_SUB_PROTOCOL_SCSI_CMD;
io_v4.request_len = sizeof (cdb);
io_v4.request = (uintptr_t) cdb;
io_v4.max_response_len = sizeof (sense);
io_v4.response = (uintptr_t) sense;
io_v4.din_xfer_len = buf_len;
io_v4.din_xferp = (uintptr_t) buf;
io_v4.timeout = COMMAND_TIMEOUT_MSEC;
ret = ioctl(fd, SG_IO, &io_v4);
if (ret != 0) {
/* could be that the driver doesn't do version 4, try version 3 */
if (errno == EINVAL) {
struct sg_io_hdr io_hdr;
memset(&io_hdr, 0, sizeof(struct sg_io_hdr));
io_hdr.interface_id = 'S';
io_hdr.cmdp = (unsigned char*) cdb;
io_hdr.cmd_len = sizeof (cdb);
io_hdr.dxferp = buf;
io_hdr.dxfer_len = buf_len;
io_hdr.sbp = sense;
io_hdr.mx_sb_len = sizeof (sense);
io_hdr.dxfer_direction = SG_DXFER_FROM_DEV;
io_hdr.timeout = COMMAND_TIMEOUT_MSEC;
ret = ioctl(fd, SG_IO, &io_hdr);
if (ret != 0)
goto out;
/* even if the ioctl succeeds, we need to check the return value */
if (!(io_hdr.status == 0 &&
io_hdr.host_status == 0 &&
io_hdr.driver_status == 0)) {
errno = EIO;
ret = -1;
goto out;
}
} else {
goto out;
}
}
/* even if the ioctl succeeds, we need to check the return value */
if (!(io_v4.device_status == 0 &&
io_v4.transport_status == 0 &&
io_v4.driver_status == 0)) {
errno = EIO;
ret = -1;
goto out;
}
out:
return ret;
}
static int disk_command(int fd, int command, int direction, void *cmd_data,
void *data, size_t *len)
static int disk_identify_command(int fd,
void *buf,
size_t buf_len)
{
uint8_t *bytes = cmd_data;
struct sg_io_v4 io_v4;
uint8_t cdb[12];
uint8_t sense[32];
uint8_t *desc = sense+8;
int ret;
/*
* ATA Pass-Through 12 byte command, as described in "T10 04-262r8
* ATA Command Pass-Through":
* http://www.t10.org/ftp/t10/document.04/04-262r8.pdf
* ATA Pass-Through 12 byte command, as described in
*
* T10 04-262r8 ATA Command Pass-Through
*
* from http://www.t10.org/ftp/t10/document.04/04-262r8.pdf
*/
memset(cdb, 0, sizeof(cdb));
cdb[0] = 0xa1; /* OPERATION CODE: 12 byte pass through */
if (direction == SG_DXFER_NONE) {
cdb[1] = 3 << 1; /* PROTOCOL: Non-Data */
cdb[2] = 0x20; /* OFF_LINE=0, CK_COND=1, T_DIR=0, BYT_BLOK=0, T_LENGTH=0 */
} else if (direction == SG_DXFER_FROM_DEV) {
cdb[1] = 4 << 1; /* PROTOCOL: PIO Data-in */
cdb[2] = 0x2e; /* OFF_LINE=0, CK_COND=1, T_DIR=1, BYT_BLOK=1, T_LENGTH=2 */
} else if (direction == SG_DXFER_TO_DEV) {
cdb[1] = 5 << 1; /* PROTOCOL: PIO Data-Out */
cdb[2] = 0x26; /* OFF_LINE=0, CK_COND=1, T_DIR=0, BYT_BLOK=1, T_LENGTH=2 */
}
cdb[3] = bytes[1]; /* FEATURES */
cdb[4] = bytes[3]; /* SECTORS */
cdb[5] = bytes[9]; /* LBA LOW */
cdb[6] = bytes[8]; /* LBA MID */
cdb[7] = bytes[7]; /* LBA HIGH */
cdb[8] = bytes[10] & 0x4F; /* SELECT */
cdb[9] = (uint8_t) command;
cdb[0] = 0xa1; /* OPERATION CODE: 12 byte pass through */
cdb[1] = 4 << 1; /* PROTOCOL: PIO Data-in */
cdb[2] = 0x2e; /* OFF_LINE=0, CK_COND=1, T_DIR=1, BYT_BLOK=1, T_LENGTH=2 */
cdb[3] = 0; /* FEATURES */
cdb[4] = 1; /* SECTORS */
cdb[5] = 0; /* LBA LOW */
cdb[6] = 0; /* LBA MID */
cdb[7] = 0; /* LBA HIGH */
cdb[8] = 0 & 0x4F; /* SELECT */
cdb[9] = 0xEC; /* Command: ATA IDENTIFY DEVICE */;
memset(sense, 0, sizeof(sense));
if ((ret = sg_io(fd, direction, cdb, sizeof(cdb), data, len ? *len : 0, sense, sizeof(sense))) < 0)
return ret;
if (sense[0] != 0x72 || desc[0] != 0x9 || desc[1] != 0x0c) {
errno = EIO;
return -1;
memset(&io_v4, 0, sizeof(struct sg_io_v4));
io_v4.guard = 'Q';
io_v4.protocol = BSG_PROTOCOL_SCSI;
io_v4.subprotocol = BSG_SUB_PROTOCOL_SCSI_CMD;
io_v4.request_len = sizeof (cdb);
io_v4.request = (uintptr_t) cdb;
io_v4.max_response_len = sizeof (sense);
io_v4.response = (uintptr_t) sense;
io_v4.din_xfer_len = buf_len;
io_v4.din_xferp = (uintptr_t) buf;
io_v4.timeout = COMMAND_TIMEOUT_MSEC;
ret = ioctl(fd, SG_IO, &io_v4);
if (ret != 0) {
/* could be that the driver doesn't do version 4, try version 3 */
if (errno == EINVAL) {
struct sg_io_hdr io_hdr;
memset(&io_hdr, 0, sizeof(struct sg_io_hdr));
io_hdr.interface_id = 'S';
io_hdr.cmdp = (unsigned char*) cdb;
io_hdr.cmd_len = sizeof (cdb);
io_hdr.dxferp = buf;
io_hdr.dxfer_len = buf_len;
io_hdr.sbp = sense;
io_hdr.mx_sb_len = sizeof (sense);
io_hdr.dxfer_direction = SG_DXFER_FROM_DEV;
io_hdr.timeout = COMMAND_TIMEOUT_MSEC;
ret = ioctl(fd, SG_IO, &io_hdr);
if (ret != 0)
goto out;
} else {
goto out;
}
}
memset(bytes, 0, 12);
bytes[1] = desc[3]; /* FEATURES */
bytes[2] = desc[4]; /* STATUS */
bytes[3] = desc[5]; /* SECTORS */
bytes[9] = desc[7]; /* LBA LOW */
bytes[8] = desc[9]; /* LBA MID */
bytes[7] = desc[11]; /* LBA HIGH */
bytes[10] = desc[12]; /* SELECT */
bytes[11] = desc[13]; /* ERROR */
if (!(sense[0] == 0x72 && desc[0] == 0x9 && desc[1] == 0x0c)) {
errno = EIO;
ret = -1;
goto out;
}
out:
return ret;
}
@ -187,78 +268,74 @@ static void disk_identify_fixup_uint16 (uint8_t identify[512], unsigned int offs
* otherwise non-zero with errno set.
*/
static int disk_identify (struct udev *udev,
int fd,
uint8_t out_identify[512])
int fd,
uint8_t out_identify[512])
{
int ret;
uint64_t size;
struct stat st;
uint16_t cmd[6];
size_t len = 512;
const uint8_t *p;
uint8_t inquiry_buf[36];
int peripheral_device_type;
int all_nul_bytes;
int n;
assert (out_identify != NULL);
/* init results */
ret = -1;
memset (out_identify, '\0', 512);
if ((ret = fstat(fd, &st)) < 0)
goto fail;
if (!S_ISBLK(st.st_mode)) {
errno = ENODEV;
goto fail;
}
/*
* do not confuse optical drive firmware with ATA commands
* some drives are reported to blank CD-RWs
/* If we were to use ATA PASS_THROUGH (12) on an ATAPI device
* we could accidentally blank media. This is because MMC's BLANK
* command has the same op-code (0x61).
*
* To prevent this from happening we bail out if the device
* isn't a Direct Access Block Device, e.g. SCSI type 0x00
* (CD/DVD devices are type 0x05). So we send a SCSI INQUIRY
* command first... libata is handling this via its SCSI
* emulation layer.
*
* This also ensures that we're actually dealing with a device
* that understands SCSI commands.
*
* (Yes, it is a bit perverse that we're tunneling the ATA
* command through SCSI and relying on the ATA driver
* emulating SCSI well-enough...)
*
* (See commit 160b069c25690bfb0c785994c7c3710289179107 for
* the original bug-fix and see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=556635
* for the original bug-report.)
*/
if (ioctl(fd, CDROM_GET_CAPABILITY, NULL) >= 0) {
errno = EIO;
ret = -1;
goto fail;
}
/* So, it's a block device. Let's make sure the ioctls work */
if ((ret = ioctl(fd, BLKGETSIZE64, &size)) < 0)
goto fail;
if (size <= 0 || size == (uint64_t) -1) {
errno = EIO;
goto fail;
}
memset(cmd, 0, sizeof(cmd));
cmd[1] = htons(1);
ret = disk_command(fd,
0xEC, /* IDENTIFY DEVICE command */
SG_DXFER_FROM_DEV, cmd,
out_identify, &len);
ret = disk_scsi_inquiry_command (fd, inquiry_buf, sizeof (inquiry_buf));
if (ret != 0)
goto fail;
goto out;
if (len != 512) {
/* SPC-4, section 6.4.2: Standard INQUIRY data */
peripheral_device_type = inquiry_buf[0] & 0x1f;
if (peripheral_device_type != 0x00) {
ret = -1;
errno = EIO;
goto fail;
goto out;
}
/* Check if IDENTIFY data is all NULs */
for (p = out_identify; p < (const uint8_t*) out_identify + len; p++) {
if (*p) {
p = NULL;
/* OK, now issue the IDENTIFY DEVICE command */
ret = disk_identify_command(fd, out_identify, 512);
if (ret != 0)
goto out;
/* Check if IDENTIFY data is all NUL bytes - if so, bail */
all_nul_bytes = 1;
for (n = 0; n < 512; n++) {
if (out_identify[n] != '\0') {
all_nul_bytes = 0;
break;
}
}
if (p) {
if (all_nul_bytes) {
ret = -1;
errno = EIO;
goto fail;
goto out;
}
ret = 0;
fail:
out:
return ret;
}