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added support for SG_IO ioctl
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async scsi commands (using read and write) do not work when you have
multiple processes, since one process's command response can get read
by another response.  The ioctl forces a blocking read after the
write.
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@joc02012
joc02012 committed Feb 9, 2013
1 parent f680ba2 commit 4856534
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Showing 2 changed files with 139 additions and 244 deletions.
130 changes: 81 additions & 49 deletions osd-initiator/device.c
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Original file line number Diff line number Diff line change
Expand Up @@ -24,84 +24,101 @@
#include "osd-util/osd-util.h"
#include <linux/bsg.h>
#include <scsi/sg.h>
#include <sys/ioctl.h>
#include "command.h"
#include "device.h"

int osd_submit_command(int fd, struct osd_command *command)
static void
osd_submit_command_setup(struct osd_command *command, struct sg_io_v4 *sg)
{
int ret;
struct sg_io_v4 sg;
memset(sg, 0, sizeof(*sg));

memset(&sg, 0, sizeof(sg));
sg.guard = 'Q';
sg.request_len = command->cdb_len;
sg.request = (uint64_t) (uintptr_t) command->cdb;
sg.max_response_len = sizeof(command->sense);
sg.response = (uint64_t) (uintptr_t) command->sense;
sg->guard = 'Q';
sg->request_len = command->cdb_len;
sg->request = (uint64_t) (uintptr_t) command->cdb;
sg->max_response_len = sizeof(command->sense);
sg->response = (uint64_t) (uintptr_t) command->sense;

if (command->outlen) {
#ifdef KERNEL_SUPPORTS_BSG_IOVEC
sg.dout_xfer_len = command->outlen;
sg.dout_xferp = (uint64_t) (uintptr_t) command->outdata;
sg.dout_iovec_count = command->iov_outlen;
sg->dout_xfer_len = command->outlen;
sg->dout_xferp = (uint64_t) (uintptr_t) command->outdata;
sg->dout_iovec_count = command->iov_outlen;
#else
// The kernel doesn't support BSG iovecs mainly because
// of a problem going from 32-bit user iovecs to a 64-bit kernel
// So, just copy the iovecs into a new buffer and use that
sg_iovec_t *iov = (sg_iovec_t *)(uintptr_t)command->outdata;
if (command->iov_outlen == 0) {
sg.dout_xfer_len = command->outlen;
sg.dout_xferp = (uint64_t) (uintptr_t) command->outdata;
sg->dout_xfer_len = command->outlen;
sg->dout_xferp = (uint64_t) (uintptr_t) command->outdata;
} else if (command->iov_outlen == 1) {
sg.dout_xfer_len = iov->iov_len;
sg.dout_xferp = (uint64_t) (uintptr_t) iov->iov_base;
sg->dout_xfer_len = iov->iov_len;
sg->dout_xferp = (uint64_t) (uintptr_t) iov->iov_base;
} else {
int i;
uint8_t *buff = Malloc(command->outlen);
sg.dout_xferp = (uint64_t) (uintptr_t) buff;
sg->dout_xferp = (uint64_t) (uintptr_t) buff;
for (i=0; i<command->iov_outlen; i++) {
memcpy(buff, iov[i].iov_base, iov[i].iov_len);
buff += iov[i].iov_len;
}
sg.dout_xfer_len = command->outlen;
sg->dout_xfer_len = command->outlen;
}
sg.dout_iovec_count = 0;
sg->dout_iovec_count = 0;
#endif
}
if (command->inlen_alloc) {
#ifdef KERNEL_SUPPORTS_BSG_IOVEC
sg.din_xfer_len = command->inlen_alloc;
sg.din_xferp = (uint64_t) (uintptr_t) command->indata;
sg.din_iovec_count = command->iov_inlen;
sg->din_xfer_len = command->inlen_alloc;
sg->din_xferp = (uint64_t) (uintptr_t) command->indata;
sg->din_iovec_count = command->iov_inlen;
#else
if (command->iov_inlen == 0) {
sg.din_xfer_len = command->inlen_alloc;
sg.din_xferp = (uint64_t) (uintptr_t) command->indata;
sg.din_iovec_count = command->iov_inlen;
sg->din_xfer_len = command->inlen_alloc;
sg->din_xferp = (uint64_t) (uintptr_t) command->indata;
sg->din_iovec_count = command->iov_inlen;
} else if (command->iov_inlen == 1) {
sg_iovec_t *iov = (sg_iovec_t *)command->indata;
sg.din_xfer_len = iov->iov_len;
sg.din_xferp = (uint64_t) (uintptr_t) iov->iov_base;
sg->din_xfer_len = iov->iov_len;
sg->din_xferp = (uint64_t) (uintptr_t) iov->iov_base;
} else {
sg.din_xfer_len = command->inlen_alloc;
sg.din_xferp = (uint64_t) (uintptr_t) (uint8_t*) Malloc(command->inlen_alloc);
sg->din_xfer_len = command->inlen_alloc;
sg->din_xferp = (uint64_t) (uintptr_t) (uint8_t*) Malloc(command->inlen_alloc);
}
sg.din_iovec_count = 0;
sg->din_iovec_count = 0;
#endif
}

/*
* Allow 30 sec for entire command. Some can be
* slow, especially with debugging messages on.
*/
sg.timeout = 30000;
sg.usr_ptr = (uint64_t) (uintptr_t) command;
ret = write(fd, &sg, sizeof(sg));
sg->timeout = 30000;
sg->usr_ptr = (uint64_t) (uintptr_t) command;
}

static void
osd_submit_command_cleanup(struct osd_command *command, struct sg_io_v4 *sg)
{
#ifndef KERNEL_SUPPORTS_BSG_IOVEC
if (command->outlen && command->iov_outlen > 1) {
free((void *) (uintptr_t) sg.dout_xferp);
free((void *) (uintptr_t) sg->dout_xferp);
}
#endif
}

int osd_submit_command(int fd, struct osd_command *command)
{
struct sg_io_v4 sg;
int ret;

osd_submit_command_setup(command, &sg);

ret = write(fd, &sg, sizeof(sg));

osd_submit_command_cleanup(command, &sg);

if (ret < 0) {
osd_error_errno("%s: write", __func__);
return -errno;
Expand All @@ -114,6 +131,8 @@ int osd_submit_command(int fd, struct osd_command *command)
return 0;
}

static void copy_sg_to_command(struct sg_io_v4 *sg, struct osd_command *command);

int osd_wait_response(int fd, struct osd_command **out_command)
{
struct sg_io_v4 sg;
Expand All @@ -132,28 +151,32 @@ int osd_wait_response(int fd, struct osd_command **out_command)
}

command = (void *)(uintptr_t) sg.usr_ptr;
copy_sg_to_command(&sg, command);

*out_command = command;

return 0;}

static void copy_sg_to_command(struct sg_io_v4 *sg, struct osd_command *command)
{
if (command->inlen_alloc)
command->inlen = command->inlen_alloc - sg.din_resid;
command->status = sg.device_status;
command->sense_len = sg.response_len;
command->inlen = command->inlen_alloc - sg->din_resid;
command->status = sg->device_status;
command->sense_len = sg->response_len;

#ifndef KERNEL_SUPPORTS_BSG_IOVEC
// copy from buffer to iovecs
if (command->inlen_alloc && command->iov_inlen > 1) {
sg_iovec_t *iov = (sg_iovec_t *) command->indata;
uint8_t *buff = (uint8_t *) (uintptr_t) sg.din_xferp;
uint8_t *buff = (uint8_t *) (uintptr_t) sg->din_xferp;
int i;
for (i=0; i<command->iov_inlen; i++) {
memcpy(iov[i].iov_base, buff, iov[i].iov_len);
buff += iov[i].iov_len;
}
free((void *) (uintptr_t) sg.din_xferp);
free((void *) (uintptr_t) sg->din_xferp);
}
#endif

*out_command = command;

return 0;
}

/*
Expand All @@ -178,17 +201,26 @@ int osd_wait_this_response(int fd, struct osd_command *command)
int osd_submit_and_wait(int fd, struct osd_command *command)
{
int ret;
struct sg_io_v4 sg;

ret = osd_submit_command(fd, command);
if (ret) {
osd_error("%s: submit failed", __func__);
return ret;
osd_submit_command_setup(command, &sg);
sg.flags = BSG_FLAG_Q_AT_TAIL;

ret = ioctl(fd, SG_IO, &sg);

osd_submit_command_cleanup(command, &sg);

if ((struct osd_command *)(uintptr_t)sg.usr_ptr != command) {
osd_error("%s: wrong command returned", __func__);
ret = -EIO;
}

ret = osd_wait_this_response(fd, command);
copy_sg_to_command(&sg, command);

if (ret) {
osd_error("%s: wait_response failed", __func__);
osd_error("%s: submit failed", __func__);
return ret;
}

return 0;
}
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