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[SCSI] use scatter lists for all block pc requests and simplify hw ha…
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…ndlers

Original From: Mike Christie <michaelc@cs.wisc.edu>

Add scsi_execute_req() as a replacement for scsi_wait_req()

Fixed up various pieces (added REQ_SPECIAL and caught req use after
free)

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
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James Bottomley committed Aug 28, 2005
1 parent 8e64011 commit 3921603
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Showing 3 changed files with 102 additions and 64 deletions.
51 changes: 50 additions & 1 deletion drivers/scsi/scsi_lib.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -246,7 +246,7 @@ void scsi_wait_req(struct scsi_request *sreq, const void *cmnd, void *buffer,
unsigned bufflen, int timeout, int retries)
{
DECLARE_COMPLETION(wait);
int write = sreq->sr_data_direction == DMA_TO_DEVICE;
int write = (sreq->sr_data_direction == DMA_TO_DEVICE);
struct request *req;

req = blk_get_request(sreq->sr_device->request_queue, write,
Expand Down Expand Up @@ -281,6 +281,55 @@ void scsi_wait_req(struct scsi_request *sreq, const void *cmnd, void *buffer,

EXPORT_SYMBOL(scsi_wait_req);

/**
* scsi_execute_req - insert request and wait for the result
* @sdev: scsi device
* @cmd: scsi command
* @data_direction: data direction
* @buffer: data buffer
* @bufflen: len of buffer
* @sense: optional sense buffer
* @timeout: request timeout in seconds
* @retries: number of times to retry request
*
* scsi_execute_req returns the req->errors value which is the
* the scsi_cmnd result field.
**/
int scsi_execute_req(struct scsi_device *sdev, unsigned char *cmd,
int data_direction, void *buffer, unsigned bufflen,
unsigned char *sense, int timeout, int retries)
{
struct request *req;
int write = (data_direction == DMA_TO_DEVICE);
int ret = DRIVER_ERROR << 24;

req = blk_get_request(sdev->request_queue, write, __GFP_WAIT);

if (bufflen && blk_rq_map_kern(sdev->request_queue, req,
buffer, bufflen, __GFP_WAIT))
goto out;

req->cmd_len = COMMAND_SIZE(cmd[0]);
memcpy(req->cmd, cmd, req->cmd_len);
req->sense = sense;
req->sense_len = 0;
req->timeout = timeout;
req->flags |= REQ_BLOCK_PC | REQ_SPECIAL;

/*
* head injection *required* here otherwise quiesce won't work
*/
blk_execute_rq(req->q, NULL, req, 1);

ret = req->errors;
out:
blk_put_request(req);

return ret;
}

EXPORT_SYMBOL(scsi_execute_req);

/*
* Function: scsi_init_cmd_errh()
*
Expand Down
112 changes: 49 additions & 63 deletions drivers/scsi/scsi_scan.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -111,15 +111,14 @@ MODULE_PARM_DESC(inq_timeout,

/**
* scsi_unlock_floptical - unlock device via a special MODE SENSE command
* @sreq: used to send the command
* @sdev: scsi device to send command to
* @result: area to store the result of the MODE SENSE
*
* Description:
* Send a vendor specific MODE SENSE (not a MODE SELECT) command using
* @sreq to unlock a device, storing the (unused) results into result.
* Send a vendor specific MODE SENSE (not a MODE SELECT) command.
* Called for BLIST_KEY devices.
**/
static void scsi_unlock_floptical(struct scsi_request *sreq,
static void scsi_unlock_floptical(struct scsi_device *sdev,
unsigned char *result)
{
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
Expand All @@ -129,11 +128,10 @@ static void scsi_unlock_floptical(struct scsi_request *sreq,
scsi_cmd[1] = 0;
scsi_cmd[2] = 0x2e;
scsi_cmd[3] = 0;
scsi_cmd[4] = 0x2a; /* size */
scsi_cmd[4] = 0x2a; /* size */
scsi_cmd[5] = 0;
sreq->sr_cmd_len = 0;
sreq->sr_data_direction = DMA_FROM_DEVICE;
scsi_wait_req(sreq, scsi_cmd, result, 0x2a /* size */, SCSI_TIMEOUT, 3);
scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL,
SCSI_TIMEOUT, 3);
}

/**
Expand Down Expand Up @@ -433,26 +431,26 @@ void scsi_target_reap(struct scsi_target *starget)

/**
* scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
* @sreq: used to send the INQUIRY
* @sdev: scsi_device to probe
* @inq_result: area to store the INQUIRY result
* @result_len: len of inq_result
* @bflags: store any bflags found here
*
* Description:
* Probe the lun associated with @sreq using a standard SCSI INQUIRY;
* Probe the lun associated with @req using a standard SCSI INQUIRY;
*
* If the INQUIRY is successful, sreq->sr_result is zero and: the
* If the INQUIRY is successful, zero is returned and the
* INQUIRY data is in @inq_result; the scsi_level and INQUIRY length
* are copied to the Scsi_Device at @sreq->sr_device (sdev);
* any flags value is stored in *@bflags.
* are copied to the Scsi_Device any flags value is stored in *@bflags.
**/
static void scsi_probe_lun(struct scsi_request *sreq, char *inq_result,
int *bflags)
static int scsi_probe_lun(struct scsi_device *sdev, char *inq_result,
int result_len, int *bflags)
{
struct scsi_device *sdev = sreq->sr_device; /* a bit ugly */
char sense[SCSI_SENSE_BUFFERSIZE];
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
int first_inquiry_len, try_inquiry_len, next_inquiry_len;
int response_len = 0;
int pass, count;
int pass, count, result;
struct scsi_sense_hdr sshdr;

*bflags = 0;
Expand All @@ -475,28 +473,28 @@ static void scsi_probe_lun(struct scsi_request *sreq, char *inq_result,
memset(scsi_cmd, 0, 6);
scsi_cmd[0] = INQUIRY;
scsi_cmd[4] = (unsigned char) try_inquiry_len;
sreq->sr_cmd_len = 0;
sreq->sr_data_direction = DMA_FROM_DEVICE;

memset(sense, 0, sizeof(sense));
memset(inq_result, 0, try_inquiry_len);
scsi_wait_req(sreq, (void *) scsi_cmd, (void *) inq_result,
try_inquiry_len,
HZ/2 + HZ*scsi_inq_timeout, 3);

result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
inq_result, try_inquiry_len, sense,
HZ / 2 + HZ * scsi_inq_timeout, 3);

SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO "scsi scan: INQUIRY %s "
"with code 0x%x\n",
sreq->sr_result ? "failed" : "successful",
sreq->sr_result));
result ? "failed" : "successful", result));

if (sreq->sr_result) {
if (result) {
/*
* not-ready to ready transition [asc/ascq=0x28/0x0]
* or power-on, reset [asc/ascq=0x29/0x0], continue.
* INQUIRY should not yield UNIT_ATTENTION
* but many buggy devices do so anyway.
*/
if ((driver_byte(sreq->sr_result) & DRIVER_SENSE) &&
scsi_request_normalize_sense(sreq, &sshdr)) {
if ((driver_byte(result) & DRIVER_SENSE) &&
scsi_normalize_sense(sense, sizeof(sense),
&sshdr)) {
if ((sshdr.sense_key == UNIT_ATTENTION) &&
((sshdr.asc == 0x28) ||
(sshdr.asc == 0x29)) &&
Expand All @@ -507,7 +505,7 @@ static void scsi_probe_lun(struct scsi_request *sreq, char *inq_result,
break;
}

if (sreq->sr_result == 0) {
if (result == 0) {
response_len = (unsigned char) inq_result[4] + 5;
if (response_len > 255)
response_len = first_inquiry_len; /* sanity */
Expand Down Expand Up @@ -556,8 +554,8 @@ static void scsi_probe_lun(struct scsi_request *sreq, char *inq_result,

/* If the last transfer attempt got an error, assume the
* peripheral doesn't exist or is dead. */
if (sreq->sr_result)
return;
if (result)
return -EIO;

/* Don't report any more data than the device says is valid */
sdev->inquiry_len = min(try_inquiry_len, response_len);
Expand Down Expand Up @@ -593,7 +591,7 @@ static void scsi_probe_lun(struct scsi_request *sreq, char *inq_result,
(sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1))
sdev->scsi_level++;

return;
return 0;
}

/**
Expand Down Expand Up @@ -800,9 +798,8 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
void *hostdata)
{
struct scsi_device *sdev;
struct scsi_request *sreq;
unsigned char *result;
int bflags, res = SCSI_SCAN_NO_RESPONSE;
int bflags, res = SCSI_SCAN_NO_RESPONSE, result_len = 256;
struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);

/*
Expand Down Expand Up @@ -831,16 +828,13 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
sdev = scsi_alloc_sdev(starget, lun, hostdata);
if (!sdev)
goto out;
sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
if (!sreq)
goto out_free_sdev;
result = kmalloc(256, GFP_ATOMIC |

result = kmalloc(result_len, GFP_ATOMIC |
((shost->unchecked_isa_dma) ? __GFP_DMA : 0));
if (!result)
goto out_free_sreq;
goto out_free_sdev;

scsi_probe_lun(sreq, result, &bflags);
if (sreq->sr_result)
if (scsi_probe_lun(sdev, result, result_len, &bflags))
goto out_free_result;

/*
Expand Down Expand Up @@ -868,16 +862,14 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
if (res == SCSI_SCAN_LUN_PRESENT) {
if (bflags & BLIST_KEY) {
sdev->lockable = 0;
scsi_unlock_floptical(sreq, result);
scsi_unlock_floptical(sdev, result);
}
if (bflagsp)
*bflagsp = bflags;
}

out_free_result:
kfree(result);
out_free_sreq:
scsi_release_request(sreq);
out_free_sdev:
if (res == SCSI_SCAN_LUN_PRESENT) {
if (sdevp) {
Expand Down Expand Up @@ -1065,13 +1057,14 @@ static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags,
int rescan)
{
char devname[64];
char sense[SCSI_SENSE_BUFFERSIZE];
unsigned char scsi_cmd[MAX_COMMAND_SIZE];
unsigned int length;
unsigned int lun;
unsigned int num_luns;
unsigned int retries;
int result;
struct scsi_lun *lunp, *lun_data;
struct scsi_request *sreq;
u8 *data;
struct scsi_sense_hdr sshdr;
struct scsi_target *starget = scsi_target(sdev);
Expand All @@ -1089,10 +1082,6 @@ static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags,
if (bflags & BLIST_NOLUN)
return 0;

sreq = scsi_allocate_request(sdev, GFP_ATOMIC);
if (!sreq)
goto out;

sprintf(devname, "host %d channel %d id %d",
sdev->host->host_no, sdev->channel, sdev->id);

Expand All @@ -1110,7 +1099,7 @@ static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags,
lun_data = kmalloc(length, GFP_ATOMIC |
(sdev->host->unchecked_isa_dma ? __GFP_DMA : 0));
if (!lun_data)
goto out_release_request;
goto out;

scsi_cmd[0] = REPORT_LUNS;

Expand All @@ -1129,8 +1118,6 @@ static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags,

scsi_cmd[10] = 0; /* reserved */
scsi_cmd[11] = 0; /* control */
sreq->sr_cmd_len = 0;
sreq->sr_data_direction = DMA_FROM_DEVICE;

/*
* We can get a UNIT ATTENTION, for example a power on/reset, so
Expand All @@ -1146,29 +1133,30 @@ static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags,
SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: Sending"
" REPORT LUNS to %s (try %d)\n", devname,
retries));
scsi_wait_req(sreq, scsi_cmd, lun_data, length,
SCSI_TIMEOUT + 4*HZ, 3);

memset(sense, 0, sizeof(sense));
result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE,
lun_data, length, sense,
SCSI_TIMEOUT + 4 * HZ, 3);

SCSI_LOG_SCAN_BUS(3, printk (KERN_INFO "scsi scan: REPORT LUNS"
" %s (try %d) result 0x%x\n", sreq->sr_result
? "failed" : "successful", retries,
sreq->sr_result));
if (sreq->sr_result == 0)
" %s (try %d) result 0x%x\n", result
? "failed" : "successful", retries, result));
if (result == 0)
break;
else if (scsi_request_normalize_sense(sreq, &sshdr)) {
else if (scsi_normalize_sense(sense, sizeof(sense), &sshdr)) {
if (sshdr.sense_key != UNIT_ATTENTION)
break;
}
}

if (sreq->sr_result) {
if (result) {
/*
* The device probably does not support a REPORT LUN command
*/
kfree(lun_data);
scsi_release_request(sreq);
return 1;
}
scsi_release_request(sreq);

/*
* Get the length from the first four bytes of lun_data.
Expand Down Expand Up @@ -1242,8 +1230,6 @@ static int scsi_report_lun_scan(struct scsi_device *sdev, int bflags,
kfree(lun_data);
return 0;

out_release_request:
scsi_release_request(sreq);
out:
/*
* We are out of memory, don't try scanning any further.
Expand Down
3 changes: 3 additions & 0 deletions include/scsi/scsi_request.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -54,6 +54,9 @@ extern void scsi_do_req(struct scsi_request *, const void *cmnd,
void *buffer, unsigned bufflen,
void (*done) (struct scsi_cmnd *),
int timeout, int retries);
extern int scsi_execute_req(struct scsi_device *sdev, unsigned char *cmd,
int data_direction, void *buffer, unsigned bufflen,
unsigned char *sense, int timeout, int retries);

struct scsi_mode_data {
__u32 length;
Expand Down

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