linux/drivers/s390/char/tape_std.c
Michael Holzheu 5f38433885 [PATCH] s390: fix endless retry loop in tape driver
If a tape device is assigned to another host, the interrupt for the assign
operation comes back with deferred condition code 1.  Under some conditions
this can lead to an endless loop of retries.  Check if the current request is
still in IO in deferred condition code handling and prevent retries when the
request has already been cancelled.

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-24 07:33:18 -08:00

764 lines
19 KiB
C

/*
* drivers/s390/char/tape_std.c
* standard tape device functions for ibm tapes.
*
* S390 and zSeries version
* Copyright (C) 2001,2002 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Carsten Otte <cotte@de.ibm.com>
* Michael Holzheu <holzheu@de.ibm.com>
* Tuan Ngo-Anh <ngoanh@de.ibm.com>
* Martin Schwidefsky <schwidefsky@de.ibm.com>
* Stefan Bader <shbader@de.ibm.com>
*/
#include <linux/config.h>
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/bio.h>
#include <linux/timer.h>
#include <asm/types.h>
#include <asm/idals.h>
#include <asm/ebcdic.h>
#include <asm/tape390.h>
#define TAPE_DBF_AREA tape_core_dbf
#include "tape.h"
#include "tape_std.h"
#define PRINTK_HEADER "TAPE_STD: "
/*
* tape_std_assign
*/
static void
tape_std_assign_timeout(unsigned long data)
{
struct tape_request * request;
struct tape_device * device;
int rc;
request = (struct tape_request *) data;
if ((device = request->device) == NULL)
BUG();
DBF_EVENT(3, "%08x: Assignment timeout. Device busy.\n",
device->cdev_id);
rc = tape_cancel_io(device, request);
if(rc)
PRINT_ERR("(%s): Assign timeout: Cancel failed with rc = %i\n",
device->cdev->dev.bus_id, rc);
}
int
tape_std_assign(struct tape_device *device)
{
int rc;
struct timer_list timeout;
struct tape_request *request;
request = tape_alloc_request(2, 11);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_ASSIGN;
tape_ccw_cc(request->cpaddr, ASSIGN, 11, request->cpdata);
tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
/*
* The assign command sometimes blocks if the device is assigned
* to another host (actually this shouldn't happen but it does).
* So we set up a timeout for this call.
*/
init_timer(&timeout);
timeout.function = tape_std_assign_timeout;
timeout.data = (unsigned long) request;
timeout.expires = jiffies + 2 * HZ;
add_timer(&timeout);
rc = tape_do_io_interruptible(device, request);
del_timer(&timeout);
if (rc != 0) {
PRINT_WARN("%s: assign failed - device might be busy\n",
device->cdev->dev.bus_id);
DBF_EVENT(3, "%08x: assign failed - device might be busy\n",
device->cdev_id);
} else {
DBF_EVENT(3, "%08x: Tape assigned\n", device->cdev_id);
}
tape_free_request(request);
return rc;
}
/*
* tape_std_unassign
*/
int
tape_std_unassign (struct tape_device *device)
{
int rc;
struct tape_request *request;
if (device->tape_state == TS_NOT_OPER) {
DBF_EVENT(3, "(%08x): Can't unassign device\n",
device->cdev_id);
PRINT_WARN("(%s): Can't unassign device - device gone\n",
device->cdev->dev.bus_id);
return -EIO;
}
request = tape_alloc_request(2, 11);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_UNASSIGN;
tape_ccw_cc(request->cpaddr, UNASSIGN, 11, request->cpdata);
tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
if ((rc = tape_do_io(device, request)) != 0) {
DBF_EVENT(3, "%08x: Unassign failed\n", device->cdev_id);
PRINT_WARN("%s: Unassign failed\n", device->cdev->dev.bus_id);
} else {
DBF_EVENT(3, "%08x: Tape unassigned\n", device->cdev_id);
}
tape_free_request(request);
return rc;
}
/*
* TAPE390_DISPLAY: Show a string on the tape display.
*/
int
tape_std_display(struct tape_device *device, struct display_struct *disp)
{
struct tape_request *request;
int rc;
request = tape_alloc_request(2, 17);
if (IS_ERR(request)) {
DBF_EVENT(3, "TAPE: load display failed\n");
return PTR_ERR(request);
}
request->op = TO_DIS;
*(unsigned char *) request->cpdata = disp->cntrl;
DBF_EVENT(5, "TAPE: display cntrl=%04x\n", disp->cntrl);
memcpy(((unsigned char *) request->cpdata) + 1, disp->message1, 8);
memcpy(((unsigned char *) request->cpdata) + 9, disp->message2, 8);
ASCEBC(((unsigned char*) request->cpdata) + 1, 16);
tape_ccw_cc(request->cpaddr, LOAD_DISPLAY, 17, request->cpdata);
tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
rc = tape_do_io_interruptible(device, request);
tape_free_request(request);
return rc;
}
/*
* Read block id.
*/
int
tape_std_read_block_id(struct tape_device *device, __u64 *id)
{
struct tape_request *request;
int rc;
request = tape_alloc_request(3, 8);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_RBI;
/* setup ccws */
tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
tape_ccw_cc(request->cpaddr + 1, READ_BLOCK_ID, 8, request->cpdata);
tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
/* execute it */
rc = tape_do_io(device, request);
if (rc == 0)
/* Get result from read buffer. */
*id = *(__u64 *) request->cpdata;
tape_free_request(request);
return rc;
}
int
tape_std_terminate_write(struct tape_device *device)
{
int rc;
if(device->required_tapemarks == 0)
return 0;
DBF_LH(5, "tape%d: terminate write %dxEOF\n", device->first_minor,
device->required_tapemarks);
rc = tape_mtop(device, MTWEOF, device->required_tapemarks);
if (rc)
return rc;
device->required_tapemarks = 0;
return tape_mtop(device, MTBSR, 1);
}
/*
* MTLOAD: Loads the tape.
* The default implementation just wait until the tape medium state changes
* to MS_LOADED.
*/
int
tape_std_mtload(struct tape_device *device, int count)
{
return wait_event_interruptible(device->state_change_wq,
(device->medium_state == MS_LOADED));
}
/*
* MTSETBLK: Set block size.
*/
int
tape_std_mtsetblk(struct tape_device *device, int count)
{
struct idal_buffer *new;
DBF_LH(6, "tape_std_mtsetblk(%d)\n", count);
if (count <= 0) {
/*
* Just set block_size to 0. tapechar_read/tapechar_write
* will realloc the idal buffer if a bigger one than the
* current is needed.
*/
device->char_data.block_size = 0;
return 0;
}
if (device->char_data.idal_buf != NULL &&
device->char_data.idal_buf->size == count)
/* We already have a idal buffer of that size. */
return 0;
if (count > MAX_BLOCKSIZE) {
DBF_EVENT(3, "Invalid block size (%d > %d) given.\n",
count, MAX_BLOCKSIZE);
PRINT_ERR("Invalid block size (%d > %d) given.\n",
count, MAX_BLOCKSIZE);
return -EINVAL;
}
/* Allocate a new idal buffer. */
new = idal_buffer_alloc(count, 0);
if (new == NULL)
return -ENOMEM;
if (device->char_data.idal_buf != NULL)
idal_buffer_free(device->char_data.idal_buf);
device->char_data.idal_buf = new;
device->char_data.block_size = count;
DBF_LH(6, "new blocksize is %d\n", device->char_data.block_size);
return 0;
}
/*
* MTRESET: Set block size to 0.
*/
int
tape_std_mtreset(struct tape_device *device, int count)
{
DBF_EVENT(6, "TCHAR:devreset:\n");
device->char_data.block_size = 0;
return 0;
}
/*
* MTFSF: Forward space over 'count' file marks. The tape is positioned
* at the EOT (End of Tape) side of the file mark.
*/
int
tape_std_mtfsf(struct tape_device *device, int mt_count)
{
struct tape_request *request;
struct ccw1 *ccw;
request = tape_alloc_request(mt_count + 2, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_FSF;
/* setup ccws */
ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
device->modeset_byte);
ccw = tape_ccw_repeat(ccw, FORSPACEFILE, mt_count);
ccw = tape_ccw_end(ccw, NOP, 0, NULL);
/* execute it */
return tape_do_io_free(device, request);
}
/*
* MTFSR: Forward space over 'count' tape blocks (blocksize is set
* via MTSETBLK.
*/
int
tape_std_mtfsr(struct tape_device *device, int mt_count)
{
struct tape_request *request;
struct ccw1 *ccw;
int rc;
request = tape_alloc_request(mt_count + 2, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_FSB;
/* setup ccws */
ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
device->modeset_byte);
ccw = tape_ccw_repeat(ccw, FORSPACEBLOCK, mt_count);
ccw = tape_ccw_end(ccw, NOP, 0, NULL);
/* execute it */
rc = tape_do_io(device, request);
if (rc == 0 && request->rescnt > 0) {
DBF_LH(3, "FSR over tapemark\n");
rc = 1;
}
tape_free_request(request);
return rc;
}
/*
* MTBSR: Backward space over 'count' tape blocks.
* (blocksize is set via MTSETBLK.
*/
int
tape_std_mtbsr(struct tape_device *device, int mt_count)
{
struct tape_request *request;
struct ccw1 *ccw;
int rc;
request = tape_alloc_request(mt_count + 2, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_BSB;
/* setup ccws */
ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
device->modeset_byte);
ccw = tape_ccw_repeat(ccw, BACKSPACEBLOCK, mt_count);
ccw = tape_ccw_end(ccw, NOP, 0, NULL);
/* execute it */
rc = tape_do_io(device, request);
if (rc == 0 && request->rescnt > 0) {
DBF_LH(3, "BSR over tapemark\n");
rc = 1;
}
tape_free_request(request);
return rc;
}
/*
* MTWEOF: Write 'count' file marks at the current position.
*/
int
tape_std_mtweof(struct tape_device *device, int mt_count)
{
struct tape_request *request;
struct ccw1 *ccw;
request = tape_alloc_request(mt_count + 2, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_WTM;
/* setup ccws */
ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
device->modeset_byte);
ccw = tape_ccw_repeat(ccw, WRITETAPEMARK, mt_count);
ccw = tape_ccw_end(ccw, NOP, 0, NULL);
/* execute it */
return tape_do_io_free(device, request);
}
/*
* MTBSFM: Backward space over 'count' file marks.
* The tape is positioned at the BOT (Begin Of Tape) side of the
* last skipped file mark.
*/
int
tape_std_mtbsfm(struct tape_device *device, int mt_count)
{
struct tape_request *request;
struct ccw1 *ccw;
request = tape_alloc_request(mt_count + 2, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_BSF;
/* setup ccws */
ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
device->modeset_byte);
ccw = tape_ccw_repeat(ccw, BACKSPACEFILE, mt_count);
ccw = tape_ccw_end(ccw, NOP, 0, NULL);
/* execute it */
return tape_do_io_free(device, request);
}
/*
* MTBSF: Backward space over 'count' file marks. The tape is positioned at
* the EOT (End of Tape) side of the last skipped file mark.
*/
int
tape_std_mtbsf(struct tape_device *device, int mt_count)
{
struct tape_request *request;
struct ccw1 *ccw;
int rc;
request = tape_alloc_request(mt_count + 2, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_BSF;
/* setup ccws */
ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
device->modeset_byte);
ccw = tape_ccw_repeat(ccw, BACKSPACEFILE, mt_count);
ccw = tape_ccw_end(ccw, NOP, 0, NULL);
/* execute it */
rc = tape_do_io_free(device, request);
if (rc == 0) {
rc = tape_mtop(device, MTFSR, 1);
if (rc > 0)
rc = 0;
}
return rc;
}
/*
* MTFSFM: Forward space over 'count' file marks.
* The tape is positioned at the BOT (Begin Of Tape) side
* of the last skipped file mark.
*/
int
tape_std_mtfsfm(struct tape_device *device, int mt_count)
{
struct tape_request *request;
struct ccw1 *ccw;
int rc;
request = tape_alloc_request(mt_count + 2, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_FSF;
/* setup ccws */
ccw = tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
device->modeset_byte);
ccw = tape_ccw_repeat(ccw, FORSPACEFILE, mt_count);
ccw = tape_ccw_end(ccw, NOP, 0, NULL);
/* execute it */
rc = tape_do_io_free(device, request);
if (rc == 0) {
rc = tape_mtop(device, MTBSR, 1);
if (rc > 0)
rc = 0;
}
return rc;
}
/*
* MTREW: Rewind the tape.
*/
int
tape_std_mtrew(struct tape_device *device, int mt_count)
{
struct tape_request *request;
request = tape_alloc_request(3, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_REW;
/* setup ccws */
tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1,
device->modeset_byte);
tape_ccw_cc(request->cpaddr + 1, REWIND, 0, NULL);
tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
/* execute it */
return tape_do_io_free(device, request);
}
/*
* MTOFFL: Rewind the tape and put the drive off-line.
* Implement 'rewind unload'
*/
int
tape_std_mtoffl(struct tape_device *device, int mt_count)
{
struct tape_request *request;
request = tape_alloc_request(3, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_RUN;
/* setup ccws */
tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
tape_ccw_cc(request->cpaddr + 1, REWIND_UNLOAD, 0, NULL);
tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
/* execute it */
return tape_do_io_free(device, request);
}
/*
* MTNOP: 'No operation'.
*/
int
tape_std_mtnop(struct tape_device *device, int mt_count)
{
struct tape_request *request;
request = tape_alloc_request(2, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_NOP;
/* setup ccws */
tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
/* execute it */
return tape_do_io_free(device, request);
}
/*
* MTEOM: positions at the end of the portion of the tape already used
* for recordind data. MTEOM positions after the last file mark, ready for
* appending another file.
*/
int
tape_std_mteom(struct tape_device *device, int mt_count)
{
int rc;
/*
* Seek from the beginning of tape (rewind).
*/
if ((rc = tape_mtop(device, MTREW, 1)) < 0)
return rc;
/*
* The logical end of volume is given by two sewuential tapemarks.
* Look for this by skipping to the next file (over one tapemark)
* and then test for another one (fsr returns 1 if a tapemark was
* encountered).
*/
do {
if ((rc = tape_mtop(device, MTFSF, 1)) < 0)
return rc;
if ((rc = tape_mtop(device, MTFSR, 1)) < 0)
return rc;
} while (rc == 0);
return tape_mtop(device, MTBSR, 1);
}
/*
* MTRETEN: Retension the tape, i.e. forward space to end of tape and rewind.
*/
int
tape_std_mtreten(struct tape_device *device, int mt_count)
{
struct tape_request *request;
int rc;
request = tape_alloc_request(4, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_FSF;
/* setup ccws */
tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
tape_ccw_cc(request->cpaddr + 1,FORSPACEFILE, 0, NULL);
tape_ccw_cc(request->cpaddr + 2, NOP, 0, NULL);
tape_ccw_end(request->cpaddr + 3, CCW_CMD_TIC, 0, request->cpaddr);
/* execute it, MTRETEN rc gets ignored */
rc = tape_do_io_interruptible(device, request);
tape_free_request(request);
return tape_mtop(device, MTREW, 1);
}
/*
* MTERASE: erases the tape.
*/
int
tape_std_mterase(struct tape_device *device, int mt_count)
{
struct tape_request *request;
request = tape_alloc_request(6, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_DSE;
/* setup ccws */
tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
tape_ccw_cc(request->cpaddr + 1, REWIND, 0, NULL);
tape_ccw_cc(request->cpaddr + 2, ERASE_GAP, 0, NULL);
tape_ccw_cc(request->cpaddr + 3, DATA_SEC_ERASE, 0, NULL);
tape_ccw_cc(request->cpaddr + 4, REWIND, 0, NULL);
tape_ccw_end(request->cpaddr + 5, NOP, 0, NULL);
/* execute it */
return tape_do_io_free(device, request);
}
/*
* MTUNLOAD: Rewind the tape and unload it.
*/
int
tape_std_mtunload(struct tape_device *device, int mt_count)
{
return tape_mtop(device, MTOFFL, mt_count);
}
/*
* MTCOMPRESSION: used to enable compression.
* Sets the IDRC on/off.
*/
int
tape_std_mtcompression(struct tape_device *device, int mt_count)
{
struct tape_request *request;
if (mt_count < 0 || mt_count > 1) {
DBF_EXCEPTION(6, "xcom parm\n");
if (*device->modeset_byte & 0x08)
PRINT_INFO("(%s) Compression is currently on\n",
device->cdev->dev.bus_id);
else
PRINT_INFO("(%s) Compression is currently off\n",
device->cdev->dev.bus_id);
PRINT_INFO("Use 1 to switch compression on, 0 to "
"switch it off\n");
return -EINVAL;
}
request = tape_alloc_request(2, 0);
if (IS_ERR(request))
return PTR_ERR(request);
request->op = TO_NOP;
/* setup ccws */
*device->modeset_byte = (mt_count == 0) ? 0x00 : 0x08;
tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
tape_ccw_end(request->cpaddr + 1, NOP, 0, NULL);
/* execute it */
return tape_do_io_free(device, request);
}
/*
* Read Block
*/
struct tape_request *
tape_std_read_block(struct tape_device *device, size_t count)
{
struct tape_request *request;
/*
* We have to alloc 4 ccws in order to be able to transform request
* into a read backward request in error case.
*/
request = tape_alloc_request(4, 0);
if (IS_ERR(request)) {
DBF_EXCEPTION(6, "xrbl fail");
return request;
}
request->op = TO_RFO;
tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
tape_ccw_end_idal(request->cpaddr + 1, READ_FORWARD,
device->char_data.idal_buf);
DBF_EVENT(6, "xrbl ccwg\n");
return request;
}
/*
* Read Block backward transformation function.
*/
void
tape_std_read_backward(struct tape_device *device, struct tape_request *request)
{
/*
* We have allocated 4 ccws in tape_std_read, so we can now
* transform the request to a read backward, followed by a
* forward space block.
*/
request->op = TO_RBA;
tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
tape_ccw_cc_idal(request->cpaddr + 1, READ_BACKWARD,
device->char_data.idal_buf);
tape_ccw_cc(request->cpaddr + 2, FORSPACEBLOCK, 0, NULL);
tape_ccw_end(request->cpaddr + 3, NOP, 0, NULL);
DBF_EVENT(6, "xrop ccwg");}
/*
* Write Block
*/
struct tape_request *
tape_std_write_block(struct tape_device *device, size_t count)
{
struct tape_request *request;
request = tape_alloc_request(2, 0);
if (IS_ERR(request)) {
DBF_EXCEPTION(6, "xwbl fail\n");
return request;
}
request->op = TO_WRI;
tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
tape_ccw_end_idal(request->cpaddr + 1, WRITE_CMD,
device->char_data.idal_buf);
DBF_EVENT(6, "xwbl ccwg\n");
return request;
}
/*
* This routine is called by frontend after an ENOSP on write
*/
void
tape_std_process_eov(struct tape_device *device)
{
/*
* End of volume: We have to backspace the last written record, then
* we TRY to write a tapemark and then backspace over the written TM
*/
if (tape_mtop(device, MTBSR, 1) == 0 &&
tape_mtop(device, MTWEOF, 1) == 0) {
tape_mtop(device, MTBSR, 1);
}
}
EXPORT_SYMBOL(tape_std_assign);
EXPORT_SYMBOL(tape_std_unassign);
EXPORT_SYMBOL(tape_std_display);
EXPORT_SYMBOL(tape_std_read_block_id);
EXPORT_SYMBOL(tape_std_mtload);
EXPORT_SYMBOL(tape_std_mtsetblk);
EXPORT_SYMBOL(tape_std_mtreset);
EXPORT_SYMBOL(tape_std_mtfsf);
EXPORT_SYMBOL(tape_std_mtfsr);
EXPORT_SYMBOL(tape_std_mtbsr);
EXPORT_SYMBOL(tape_std_mtweof);
EXPORT_SYMBOL(tape_std_mtbsfm);
EXPORT_SYMBOL(tape_std_mtbsf);
EXPORT_SYMBOL(tape_std_mtfsfm);
EXPORT_SYMBOL(tape_std_mtrew);
EXPORT_SYMBOL(tape_std_mtoffl);
EXPORT_SYMBOL(tape_std_mtnop);
EXPORT_SYMBOL(tape_std_mteom);
EXPORT_SYMBOL(tape_std_mtreten);
EXPORT_SYMBOL(tape_std_mterase);
EXPORT_SYMBOL(tape_std_mtunload);
EXPORT_SYMBOL(tape_std_mtcompression);
EXPORT_SYMBOL(tape_std_read_block);
EXPORT_SYMBOL(tape_std_read_backward);
EXPORT_SYMBOL(tape_std_write_block);
EXPORT_SYMBOL(tape_std_process_eov);