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linux/drivers/s390/block/dasd.c
Horst Hummel 90f0094dc6 [PATCH] s390: dasd partition detection 
DASD allows to open a device as soon as gendisk is registered, which means the
device is a fake device (capacity=0) and we do know nothing about blocksize
and partitions at that point of time.  In case the device is opened by
someone, the bdev and inode creation is done with the fake device info and the
following partition detection code is just using the wrong data.

To avoid this modify the DASD state machine to make sure that the open is
rejected until the device analysis is either finished or an unformatted device
was detected.

Signed-off-by: Horst Hummel <horst.hummel@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-08 14:14:01 -08:00

2163 lines
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/*
* File...........: linux/drivers/s390/block/dasd.c
* Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
* Horst Hummel <Horst.Hummel@de.ibm.com>
* Carsten Otte <Cotte@de.ibm.com>
* Martin Schwidefsky <schwidefsky@de.ibm.com>
* Bugreports.to..: <Linux390@de.ibm.com>
* (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999-2001
*
*/
#include <linux/config.h>
#include <linux/kmod.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/ctype.h>
#include <linux/major.h>
#include <linux/slab.h>
#include <linux/buffer_head.h>
#include <linux/hdreg.h>
#include <asm/ccwdev.h>
#include <asm/ebcdic.h>
#include <asm/idals.h>
#include <asm/todclk.h>
/* This is ugly... */
#define PRINTK_HEADER "dasd:"
#include "dasd_int.h"
/*
* SECTION: Constant definitions to be used within this file
*/
#define DASD_CHANQ_MAX_SIZE 4
/*
* SECTION: exported variables of dasd.c
*/
debug_info_t *dasd_debug_area;
struct dasd_discipline *dasd_diag_discipline_pointer;
MODULE_AUTHOR("Holger Smolinski <Holger.Smolinski@de.ibm.com>");
MODULE_DESCRIPTION("Linux on S/390 DASD device driver,"
" Copyright 2000 IBM Corporation");
MODULE_SUPPORTED_DEVICE("dasd");
MODULE_PARM(dasd, "1-" __MODULE_STRING(256) "s");
MODULE_LICENSE("GPL");
/*
* SECTION: prototypes for static functions of dasd.c
*/
static int dasd_alloc_queue(struct dasd_device * device);
static void dasd_setup_queue(struct dasd_device * device);
static void dasd_free_queue(struct dasd_device * device);
static void dasd_flush_request_queue(struct dasd_device *);
static void dasd_int_handler(struct ccw_device *, unsigned long, struct irb *);
static void dasd_flush_ccw_queue(struct dasd_device *, int);
static void dasd_tasklet(struct dasd_device *);
static void do_kick_device(void *data);
/*
* SECTION: Operations on the device structure.
*/
static wait_queue_head_t dasd_init_waitq;
/*
* Allocate memory for a new device structure.
*/
struct dasd_device *
dasd_alloc_device(void)
{
struct dasd_device *device;
device = kmalloc(sizeof (struct dasd_device), GFP_ATOMIC);
if (device == NULL)
return ERR_PTR(-ENOMEM);
memset(device, 0, sizeof (struct dasd_device));
/* open_count = 0 means device online but not in use */
atomic_set(&device->open_count, -1);
/* Get two pages for normal block device operations. */
device->ccw_mem = (void *) __get_free_pages(GFP_ATOMIC | GFP_DMA, 1);
if (device->ccw_mem == NULL) {
kfree(device);
return ERR_PTR(-ENOMEM);
}
/* Get one page for error recovery. */
device->erp_mem = (void *) get_zeroed_page(GFP_ATOMIC | GFP_DMA);
if (device->erp_mem == NULL) {
free_pages((unsigned long) device->ccw_mem, 1);
kfree(device);
return ERR_PTR(-ENOMEM);
}
dasd_init_chunklist(&device->ccw_chunks, device->ccw_mem, PAGE_SIZE*2);
dasd_init_chunklist(&device->erp_chunks, device->erp_mem, PAGE_SIZE);
spin_lock_init(&device->mem_lock);
spin_lock_init(&device->request_queue_lock);
atomic_set (&device->tasklet_scheduled, 0);
tasklet_init(&device->tasklet,
(void (*)(unsigned long)) dasd_tasklet,
(unsigned long) device);
INIT_LIST_HEAD(&device->ccw_queue);
init_timer(&device->timer);
INIT_WORK(&device->kick_work, do_kick_device, device);
device->state = DASD_STATE_NEW;
device->target = DASD_STATE_NEW;
return device;
}
/*
* Free memory of a device structure.
*/
void
dasd_free_device(struct dasd_device *device)
{
kfree(device->private);
free_page((unsigned long) device->erp_mem);
free_pages((unsigned long) device->ccw_mem, 1);
kfree(device);
}
/*
* Make a new device known to the system.
*/
static inline int
dasd_state_new_to_known(struct dasd_device *device)
{
int rc;
/*
* As long as the device is not in state DASD_STATE_NEW we want to
* keep the reference count > 0.
*/
dasd_get_device(device);
rc = dasd_alloc_queue(device);
if (rc) {
dasd_put_device(device);
return rc;
}
device->state = DASD_STATE_KNOWN;
return 0;
}
/*
* Let the system forget about a device.
*/
static inline void
dasd_state_known_to_new(struct dasd_device * device)
{
/* Forget the discipline information. */
if (device->discipline)
module_put(device->discipline->owner);
device->discipline = NULL;
if (device->base_discipline)
module_put(device->base_discipline->owner);
device->base_discipline = NULL;
device->state = DASD_STATE_NEW;
dasd_free_queue(device);
/* Give up reference we took in dasd_state_new_to_known. */
dasd_put_device(device);
}
/*
* Request the irq line for the device.
*/
static inline int
dasd_state_known_to_basic(struct dasd_device * device)
{
int rc;
/* Allocate and register gendisk structure. */
rc = dasd_gendisk_alloc(device);
if (rc)
return rc;
/* register 'device' debug area, used for all DBF_DEV_XXX calls */
device->debug_area = debug_register(device->cdev->dev.bus_id, 1, 2,
8 * sizeof (long));
debug_register_view(device->debug_area, &debug_sprintf_view);
debug_set_level(device->debug_area, DBF_EMERG);
DBF_DEV_EVENT(DBF_EMERG, device, "%s", "debug area created");
device->state = DASD_STATE_BASIC;
return 0;
}
/*
* Release the irq line for the device. Terminate any running i/o.
*/
static inline void
dasd_state_basic_to_known(struct dasd_device * device)
{
dasd_gendisk_free(device);
dasd_flush_ccw_queue(device, 1);
DBF_DEV_EVENT(DBF_EMERG, device, "%p debug area deleted", device);
if (device->debug_area != NULL) {
debug_unregister(device->debug_area);
device->debug_area = NULL;
}
device->state = DASD_STATE_KNOWN;
}
/*
* Do the initial analysis. The do_analysis function may return
* -EAGAIN in which case the device keeps the state DASD_STATE_BASIC
* until the discipline decides to continue the startup sequence
* by calling the function dasd_change_state. The eckd disciplines
* uses this to start a ccw that detects the format. The completion
* interrupt for this detection ccw uses the kernel event daemon to
* trigger the call to dasd_change_state. All this is done in the
* discipline code, see dasd_eckd.c.
* After the analysis ccw is done (do_analysis returned 0) the block
* device is setup.
* In case the analysis returns an error, the device setup is stopped
* (a fake disk was already added to allow formatting).
*/
static inline int
dasd_state_basic_to_ready(struct dasd_device * device)
{
int rc;
rc = 0;
if (device->discipline->do_analysis != NULL)
rc = device->discipline->do_analysis(device);
if (rc) {
if (rc != -EAGAIN)
device->state = DASD_STATE_UNFMT;
return rc;
}
/* make disk known with correct capacity */
dasd_setup_queue(device);
set_capacity(device->gdp, device->blocks << device->s2b_shift);
device->state = DASD_STATE_READY;
rc = dasd_scan_partitions(device);
if (rc)
device->state = DASD_STATE_BASIC;
return rc;
}
/*
* Remove device from block device layer. Destroy dirty buffers.
* Forget format information. Check if the target level is basic
* and if it is create fake disk for formatting.
*/
static inline void
dasd_state_ready_to_basic(struct dasd_device * device)
{
dasd_flush_ccw_queue(device, 0);
dasd_destroy_partitions(device);
dasd_flush_request_queue(device);
device->blocks = 0;
device->bp_block = 0;
device->s2b_shift = 0;
device->state = DASD_STATE_BASIC;
}
/*
* Back to basic.
*/
static inline void
dasd_state_unfmt_to_basic(struct dasd_device * device)
{
device->state = DASD_STATE_BASIC;
}
/*
* Make the device online and schedule the bottom half to start
* the requeueing of requests from the linux request queue to the
* ccw queue.
*/
static inline int
dasd_state_ready_to_online(struct dasd_device * device)
{
device->state = DASD_STATE_ONLINE;
dasd_schedule_bh(device);
return 0;
}
/*
* Stop the requeueing of requests again.
*/
static inline void
dasd_state_online_to_ready(struct dasd_device * device)
{
device->state = DASD_STATE_READY;
}
/*
* Device startup state changes.
*/
static inline int
dasd_increase_state(struct dasd_device *device)
{
int rc;
rc = 0;
if (device->state == DASD_STATE_NEW &&
device->target >= DASD_STATE_KNOWN)
rc = dasd_state_new_to_known(device);
if (!rc &&
device->state == DASD_STATE_KNOWN &&
device->target >= DASD_STATE_BASIC)
rc = dasd_state_known_to_basic(device);
if (!rc &&
device->state == DASD_STATE_BASIC &&
device->target >= DASD_STATE_READY)
rc = dasd_state_basic_to_ready(device);
if (!rc &&
device->state == DASD_STATE_READY &&
device->target >= DASD_STATE_ONLINE)
rc = dasd_state_ready_to_online(device);
return rc;
}
/*
* Device shutdown state changes.
*/
static inline int
dasd_decrease_state(struct dasd_device *device)
{
if (device->state == DASD_STATE_ONLINE &&
device->target <= DASD_STATE_READY)
dasd_state_online_to_ready(device);
if (device->state == DASD_STATE_READY &&
device->target <= DASD_STATE_BASIC)
dasd_state_ready_to_basic(device);
if (device->state == DASD_STATE_UNFMT &&
device->target <= DASD_STATE_BASIC)
dasd_state_unfmt_to_basic(device);
if (device->state == DASD_STATE_BASIC &&
device->target <= DASD_STATE_KNOWN)
dasd_state_basic_to_known(device);
if (device->state == DASD_STATE_KNOWN &&
device->target <= DASD_STATE_NEW)
dasd_state_known_to_new(device);
return 0;
}
/*
* This is the main startup/shutdown routine.
*/
static void
dasd_change_state(struct dasd_device *device)
{
int rc;
if (device->state == device->target)
/* Already where we want to go today... */
return;
if (device->state < device->target)
rc = dasd_increase_state(device);
else
rc = dasd_decrease_state(device);
if (rc && rc != -EAGAIN)
device->target = device->state;
if (device->state == device->target)
wake_up(&dasd_init_waitq);
}
/*
* Kick starter for devices that did not complete the startup/shutdown
* procedure or were sleeping because of a pending state.
* dasd_kick_device will schedule a call do do_kick_device to the kernel
* event daemon.
*/
static void
do_kick_device(void *data)
{
struct dasd_device *device;
device = (struct dasd_device *) data;
dasd_change_state(device);
dasd_schedule_bh(device);
dasd_put_device(device);
}
void
dasd_kick_device(struct dasd_device *device)
{
dasd_get_device(device);
/* queue call to dasd_kick_device to the kernel event daemon. */
schedule_work(&device->kick_work);
}
/*
* Set the target state for a device and starts the state change.
*/
void
dasd_set_target_state(struct dasd_device *device, int target)
{
/* If we are in probeonly mode stop at DASD_STATE_READY. */
if (dasd_probeonly && target > DASD_STATE_READY)
target = DASD_STATE_READY;
if (device->target != target) {
if (device->state == target)
wake_up(&dasd_init_waitq);
device->target = target;
}
if (device->state != device->target)
dasd_change_state(device);
}
/*
* Enable devices with device numbers in [from..to].
*/
static inline int
_wait_for_device(struct dasd_device *device)
{
return (device->state == device->target);
}
void
dasd_enable_device(struct dasd_device *device)
{
dasd_set_target_state(device, DASD_STATE_ONLINE);
if (device->state <= DASD_STATE_KNOWN)
/* No discipline for device found. */
dasd_set_target_state(device, DASD_STATE_NEW);
/* Now wait for the devices to come up. */
wait_event(dasd_init_waitq, _wait_for_device(device));
}
/*
* SECTION: device operation (interrupt handler, start i/o, term i/o ...)
*/
#ifdef CONFIG_DASD_PROFILE
struct dasd_profile_info_t dasd_global_profile;
unsigned int dasd_profile_level = DASD_PROFILE_OFF;
/*
* Increments counter in global and local profiling structures.
*/
#define dasd_profile_counter(value, counter, device) \
{ \
int index; \
for (index = 0; index < 31 && value >> (2+index); index++); \
dasd_global_profile.counter[index]++; \
device->profile.counter[index]++; \
}
/*
* Add profiling information for cqr before execution.
*/
static inline void
dasd_profile_start(struct dasd_device *device, struct dasd_ccw_req * cqr,
struct request *req)
{
struct list_head *l;
unsigned int counter;
if (dasd_profile_level != DASD_PROFILE_ON)
return;
/* count the length of the chanq for statistics */
counter = 0;
list_for_each(l, &device->ccw_queue)
if (++counter >= 31)
break;
dasd_global_profile.dasd_io_nr_req[counter]++;
device->profile.dasd_io_nr_req[counter]++;
}
/*
* Add profiling information for cqr after execution.
*/
static inline void
dasd_profile_end(struct dasd_device *device, struct dasd_ccw_req * cqr,
struct request *req)
{
long strtime, irqtime, endtime, tottime; /* in microseconds */
long tottimeps, sectors;
if (dasd_profile_level != DASD_PROFILE_ON)
return;
sectors = req->nr_sectors;
if (!cqr->buildclk || !cqr->startclk ||
!cqr->stopclk || !cqr->endclk ||
!sectors)
return;
strtime = ((cqr->startclk - cqr->buildclk) >> 12);
irqtime = ((cqr->stopclk - cqr->startclk) >> 12);
endtime = ((cqr->endclk - cqr->stopclk) >> 12);
tottime = ((cqr->endclk - cqr->buildclk) >> 12);
tottimeps = tottime / sectors;
if (!dasd_global_profile.dasd_io_reqs)
memset(&dasd_global_profile, 0,
sizeof (struct dasd_profile_info_t));
dasd_global_profile.dasd_io_reqs++;
dasd_global_profile.dasd_io_sects += sectors;
if (!device->profile.dasd_io_reqs)
memset(&device->profile, 0,
sizeof (struct dasd_profile_info_t));
device->profile.dasd_io_reqs++;
device->profile.dasd_io_sects += sectors;
dasd_profile_counter(sectors, dasd_io_secs, device);
dasd_profile_counter(tottime, dasd_io_times, device);
dasd_profile_counter(tottimeps, dasd_io_timps, device);
dasd_profile_counter(strtime, dasd_io_time1, device);
dasd_profile_counter(irqtime, dasd_io_time2, device);
dasd_profile_counter(irqtime / sectors, dasd_io_time2ps, device);
dasd_profile_counter(endtime, dasd_io_time3, device);
}
#else
#define dasd_profile_start(device, cqr, req) do {} while (0)
#define dasd_profile_end(device, cqr, req) do {} while (0)
#endif /* CONFIG_DASD_PROFILE */
/*
* Allocate memory for a channel program with 'cplength' channel
* command words and 'datasize' additional space. There are two
* variantes: 1) dasd_kmalloc_request uses kmalloc to get the needed
* memory and 2) dasd_smalloc_request uses the static ccw memory
* that gets allocated for each device.
*/
struct dasd_ccw_req *
dasd_kmalloc_request(char *magic, int cplength, int datasize,
struct dasd_device * device)
{
struct dasd_ccw_req *cqr;
/* Sanity checks */
if ( magic == NULL || datasize > PAGE_SIZE ||
(cplength*sizeof(struct ccw1)) > PAGE_SIZE)
BUG();
cqr = kmalloc(sizeof(struct dasd_ccw_req), GFP_ATOMIC);
if (cqr == NULL)
return ERR_PTR(-ENOMEM);
memset(cqr, 0, sizeof(struct dasd_ccw_req));
cqr->cpaddr = NULL;
if (cplength > 0) {
cqr->cpaddr = kmalloc(cplength*sizeof(struct ccw1),
GFP_ATOMIC | GFP_DMA);
if (cqr->cpaddr == NULL) {
kfree(cqr);
return ERR_PTR(-ENOMEM);
}
memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
}
cqr->data = NULL;
if (datasize > 0) {
cqr->data = kmalloc(datasize, GFP_ATOMIC | GFP_DMA);
if (cqr->data == NULL) {
kfree(cqr->cpaddr);
kfree(cqr);
return ERR_PTR(-ENOMEM);
}
memset(cqr->data, 0, datasize);
}
strncpy((char *) &cqr->magic, magic, 4);
ASCEBC((char *) &cqr->magic, 4);
set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
dasd_get_device(device);
return cqr;
}
struct dasd_ccw_req *
dasd_smalloc_request(char *magic, int cplength, int datasize,
struct dasd_device * device)
{
unsigned long flags;
struct dasd_ccw_req *cqr;
char *data;
int size;
/* Sanity checks */
if ( magic == NULL || datasize > PAGE_SIZE ||
(cplength*sizeof(struct ccw1)) > PAGE_SIZE)
BUG();
size = (sizeof(struct dasd_ccw_req) + 7L) & -8L;
if (cplength > 0)
size += cplength * sizeof(struct ccw1);
if (datasize > 0)
size += datasize;
spin_lock_irqsave(&device->mem_lock, flags);
cqr = (struct dasd_ccw_req *)
dasd_alloc_chunk(&device->ccw_chunks, size);
spin_unlock_irqrestore(&device->mem_lock, flags);
if (cqr == NULL)
return ERR_PTR(-ENOMEM);
memset(cqr, 0, sizeof(struct dasd_ccw_req));
data = (char *) cqr + ((sizeof(struct dasd_ccw_req) + 7L) & -8L);
cqr->cpaddr = NULL;
if (cplength > 0) {
cqr->cpaddr = (struct ccw1 *) data;
data += cplength*sizeof(struct ccw1);
memset(cqr->cpaddr, 0, cplength*sizeof(struct ccw1));
}
cqr->data = NULL;
if (datasize > 0) {
cqr->data = data;
memset(cqr->data, 0, datasize);
}
strncpy((char *) &cqr->magic, magic, 4);
ASCEBC((char *) &cqr->magic, 4);
set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
dasd_get_device(device);
return cqr;
}
/*
* Free memory of a channel program. This function needs to free all the
* idal lists that might have been created by dasd_set_cda and the
* struct dasd_ccw_req itself.
*/
void
dasd_kfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
{
#ifdef CONFIG_64BIT
struct ccw1 *ccw;
/* Clear any idals used for the request. */
ccw = cqr->cpaddr;
do {
clear_normalized_cda(ccw);
} while (ccw++->flags & (CCW_FLAG_CC | CCW_FLAG_DC));
#endif
kfree(cqr->cpaddr);
kfree(cqr->data);
kfree(cqr);
dasd_put_device(device);
}
void
dasd_sfree_request(struct dasd_ccw_req * cqr, struct dasd_device * device)
{
unsigned long flags;
spin_lock_irqsave(&device->mem_lock, flags);
dasd_free_chunk(&device->ccw_chunks, cqr);
spin_unlock_irqrestore(&device->mem_lock, flags);
dasd_put_device(device);
}
/*
* Check discipline magic in cqr.
*/
static inline int
dasd_check_cqr(struct dasd_ccw_req *cqr)
{
struct dasd_device *device;
if (cqr == NULL)
return -EINVAL;
device = cqr->device;
if (strncmp((char *) &cqr->magic, device->discipline->ebcname, 4)) {
DEV_MESSAGE(KERN_WARNING, device,
" dasd_ccw_req 0x%08x magic doesn't match"
" discipline 0x%08x",
cqr->magic,
*(unsigned int *) device->discipline->name);
return -EINVAL;
}
return 0;
}
/*
* Terminate the current i/o and set the request to clear_pending.
* Timer keeps device runnig.
* ccw_device_clear can fail if the i/o subsystem
* is in a bad mood.
*/
int
dasd_term_IO(struct dasd_ccw_req * cqr)
{
struct dasd_device *device;
int retries, rc;
/* Check the cqr */
rc = dasd_check_cqr(cqr);
if (rc)
return rc;
retries = 0;
device = (struct dasd_device *) cqr->device;
while ((retries < 5) && (cqr->status == DASD_CQR_IN_IO)) {
rc = ccw_device_clear(device->cdev, (long) cqr);
switch (rc) {
case 0: /* termination successful */
cqr->retries--;
cqr->status = DASD_CQR_CLEAR;
cqr->stopclk = get_clock();
DBF_DEV_EVENT(DBF_DEBUG, device,
"terminate cqr %p successful",
cqr);
break;
case -ENODEV:
DBF_DEV_EVENT(DBF_ERR, device, "%s",
"device gone, retry");
break;
case -EIO:
DBF_DEV_EVENT(DBF_ERR, device, "%s",
"I/O error, retry");
break;
case -EINVAL:
case -EBUSY:
DBF_DEV_EVENT(DBF_ERR, device, "%s",
"device busy, retry later");
break;
default:
DEV_MESSAGE(KERN_ERR, device,
"line %d unknown RC=%d, please "
"report to linux390@de.ibm.com",
__LINE__, rc);
BUG();
break;
}
retries++;
}
dasd_schedule_bh(device);
return rc;
}
/*
* Start the i/o. This start_IO can fail if the channel is really busy.
* In that case set up a timer to start the request later.
*/
int
dasd_start_IO(struct dasd_ccw_req * cqr)
{
struct dasd_device *device;
int rc;
/* Check the cqr */
rc = dasd_check_cqr(cqr);
if (rc)
return rc;
device = (struct dasd_device *) cqr->device;
if (cqr->retries < 0) {
DEV_MESSAGE(KERN_DEBUG, device,
"start_IO: request %p (%02x/%i) - no retry left.",
cqr, cqr->status, cqr->retries);
cqr->status = DASD_CQR_FAILED;
return -EIO;
}
cqr->startclk = get_clock();
cqr->starttime = jiffies;
cqr->retries--;
rc = ccw_device_start(device->cdev, cqr->cpaddr, (long) cqr,
cqr->lpm, 0);
switch (rc) {
case 0:
cqr->status = DASD_CQR_IN_IO;
DBF_DEV_EVENT(DBF_DEBUG, device,
"start_IO: request %p started successful",
cqr);
break;
case -EBUSY:
DBF_DEV_EVENT(DBF_ERR, device, "%s",
"start_IO: device busy, retry later");
break;
case -ETIMEDOUT:
DBF_DEV_EVENT(DBF_ERR, device, "%s",
"start_IO: request timeout, retry later");
break;
case -EACCES:
/* -EACCES indicates that the request used only a
* subset of the available pathes and all these
* pathes are gone.
* Do a retry with all available pathes.
*/
cqr->lpm = LPM_ANYPATH;
DBF_DEV_EVENT(DBF_ERR, device, "%s",
"start_IO: selected pathes gone,"
" retry on all pathes");
break;
case -ENODEV:
case -EIO:
DBF_DEV_EVENT(DBF_ERR, device, "%s",
"start_IO: device gone, retry");
break;
default:
DEV_MESSAGE(KERN_ERR, device,
"line %d unknown RC=%d, please report"
" to linux390@de.ibm.com", __LINE__, rc);
BUG();
break;
}
return rc;
}
/*
* Timeout function for dasd devices. This is used for different purposes
* 1) missing interrupt handler for normal operation
* 2) delayed start of request where start_IO failed with -EBUSY
* 3) timeout for missing state change interrupts
* The head of the ccw queue will have status DASD_CQR_IN_IO for 1),
* DASD_CQR_QUEUED for 2) and 3).
*/
static void
dasd_timeout_device(unsigned long ptr)
{
unsigned long flags;
struct dasd_device *device;
device = (struct dasd_device *) ptr;
spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
/* re-activate request queue */
device->stopped &= ~DASD_STOPPED_PENDING;
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
dasd_schedule_bh(device);
}
/*
* Setup timeout for a device in jiffies.
*/
void
dasd_set_timer(struct dasd_device *device, int expires)
{
if (expires == 0) {
if (timer_pending(&device->timer))
del_timer(&device->timer);
return;
}
if (timer_pending(&device->timer)) {
if (mod_timer(&device->timer, jiffies + expires))
return;
}
device->timer.function = dasd_timeout_device;
device->timer.data = (unsigned long) device;
device->timer.expires = jiffies + expires;
add_timer(&device->timer);
}
/*
* Clear timeout for a device.
*/
void
dasd_clear_timer(struct dasd_device *device)
{
if (timer_pending(&device->timer))
del_timer(&device->timer);
}
static void
dasd_handle_killed_request(struct ccw_device *cdev, unsigned long intparm)
{
struct dasd_ccw_req *cqr;
struct dasd_device *device;
cqr = (struct dasd_ccw_req *) intparm;
if (cqr->status != DASD_CQR_IN_IO) {
MESSAGE(KERN_DEBUG,
"invalid status in handle_killed_request: "
"bus_id %s, status %02x",
cdev->dev.bus_id, cqr->status);
return;
}
device = (struct dasd_device *) cqr->device;
if (device == NULL ||
device != dasd_device_from_cdev(cdev) ||
strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
cdev->dev.bus_id);
return;
}
/* Schedule request to be retried. */
cqr->status = DASD_CQR_QUEUED;
dasd_clear_timer(device);
dasd_schedule_bh(device);
dasd_put_device(device);
}
static void
dasd_handle_state_change_pending(struct dasd_device *device)
{
struct dasd_ccw_req *cqr;
struct list_head *l, *n;
device->stopped &= ~DASD_STOPPED_PENDING;
/* restart all 'running' IO on queue */
list_for_each_safe(l, n, &device->ccw_queue) {
cqr = list_entry(l, struct dasd_ccw_req, list);
if (cqr->status == DASD_CQR_IN_IO) {
cqr->status = DASD_CQR_QUEUED;
}
}
dasd_clear_timer(device);
dasd_schedule_bh(device);
}
/*
* Interrupt handler for "normal" ssch-io based dasd devices.
*/
void
dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
struct irb *irb)
{
struct dasd_ccw_req *cqr, *next;
struct dasd_device *device;
unsigned long long now;
int expires;
dasd_era_t era;
char mask;
if (IS_ERR(irb)) {
switch (PTR_ERR(irb)) {
case -EIO:
dasd_handle_killed_request(cdev, intparm);
break;
case -ETIMEDOUT:
printk(KERN_WARNING"%s(%s): request timed out\n",
__FUNCTION__, cdev->dev.bus_id);
//FIXME - dasd uses own timeout interface...
break;
default:
printk(KERN_WARNING"%s(%s): unknown error %ld\n",
__FUNCTION__, cdev->dev.bus_id, PTR_ERR(irb));
}
return;
}
now = get_clock();
DBF_EVENT(DBF_ERR, "Interrupt: bus_id %s CS/DS %04x ip %08x",
cdev->dev.bus_id, ((irb->scsw.cstat<<8)|irb->scsw.dstat),
(unsigned int) intparm);
/* first of all check for state change pending interrupt */
mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
if ((irb->scsw.dstat & mask) == mask) {
device = dasd_device_from_cdev(cdev);
if (!IS_ERR(device)) {
dasd_handle_state_change_pending(device);
dasd_put_device(device);
}
return;
}
cqr = (struct dasd_ccw_req *) intparm;
/* check for unsolicited interrupts */
if (cqr == NULL) {
MESSAGE(KERN_DEBUG,
"unsolicited interrupt received: bus_id %s",
cdev->dev.bus_id);
return;
}
device = (struct dasd_device *) cqr->device;
if (device == NULL ||
strncmp(device->discipline->ebcname, (char *) &cqr->magic, 4)) {
MESSAGE(KERN_DEBUG, "invalid device in request: bus_id %s",
cdev->dev.bus_id);
return;
}
/* Check for clear pending */
if (cqr->status == DASD_CQR_CLEAR &&
irb->scsw.fctl & SCSW_FCTL_CLEAR_FUNC) {
cqr->status = DASD_CQR_QUEUED;
dasd_clear_timer(device);
dasd_schedule_bh(device);
return;
}
/* check status - the request might have been killed by dyn detach */
if (cqr->status != DASD_CQR_IN_IO) {
MESSAGE(KERN_DEBUG,
"invalid status: bus_id %s, status %02x",
cdev->dev.bus_id, cqr->status);
return;
}
DBF_DEV_EVENT(DBF_DEBUG, device, "Int: CS/DS 0x%04x for cqr %p",
((irb->scsw.cstat << 8) | irb->scsw.dstat), cqr);
/* Find out the appropriate era_action. */
if (irb->scsw.fctl & SCSW_FCTL_HALT_FUNC)
era = dasd_era_fatal;
else if (irb->scsw.dstat == (DEV_STAT_CHN_END | DEV_STAT_DEV_END) &&
irb->scsw.cstat == 0 &&
!irb->esw.esw0.erw.cons)
era = dasd_era_none;
else if (!test_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags))
era = dasd_era_fatal; /* don't recover this request */
else if (irb->esw.esw0.erw.cons)
era = device->discipline->examine_error(cqr, irb);
else
era = dasd_era_recover;
DBF_DEV_EVENT(DBF_DEBUG, device, "era_code %d", era);
expires = 0;
if (era == dasd_era_none) {
cqr->status = DASD_CQR_DONE;
cqr->stopclk = now;
/* Start first request on queue if possible -> fast_io. */
if (cqr->list.next != &device->ccw_queue) {
next = list_entry(cqr->list.next,
struct dasd_ccw_req, list);
if ((next->status == DASD_CQR_QUEUED) &&
(!device->stopped)) {
if (device->discipline->start_IO(next) == 0)
expires = next->expires;
else
DEV_MESSAGE(KERN_DEBUG, device, "%s",
"Interrupt fastpath "
"failed!");
}
}
} else { /* error */
memcpy(&cqr->irb, irb, sizeof (struct irb));
#ifdef ERP_DEBUG
/* dump sense data */
dasd_log_sense(cqr, irb);
#endif
switch (era) {
case dasd_era_fatal:
cqr->status = DASD_CQR_FAILED;
cqr->stopclk = now;
break;
case dasd_era_recover:
cqr->status = DASD_CQR_ERROR;
break;
default:
BUG();
}
}
if (expires != 0)
dasd_set_timer(device, expires);
else
dasd_clear_timer(device);
dasd_schedule_bh(device);
}
/*
* posts the buffer_cache about a finalized request
*/
static inline void
dasd_end_request(struct request *req, int uptodate)
{
if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
BUG();
add_disk_randomness(req->rq_disk);
end_that_request_last(req, uptodate);
}
/*
* Process finished error recovery ccw.
*/
static inline void
__dasd_process_erp(struct dasd_device *device, struct dasd_ccw_req *cqr)
{
dasd_erp_fn_t erp_fn;
if (cqr->status == DASD_CQR_DONE)
DBF_DEV_EVENT(DBF_NOTICE, device, "%s", "ERP successful");
else
DEV_MESSAGE(KERN_ERR, device, "%s", "ERP unsuccessful");
erp_fn = device->discipline->erp_postaction(cqr);
erp_fn(cqr);
}
/*
* Process ccw request queue.
*/
static inline void
__dasd_process_ccw_queue(struct dasd_device * device,
struct list_head *final_queue)
{
struct list_head *l, *n;
struct dasd_ccw_req *cqr;
dasd_erp_fn_t erp_fn;
restart:
/* Process request with final status. */
list_for_each_safe(l, n, &device->ccw_queue) {
cqr = list_entry(l, struct dasd_ccw_req, list);
/* Stop list processing at the first non-final request. */
if (cqr->status != DASD_CQR_DONE &&
cqr->status != DASD_CQR_FAILED &&
cqr->status != DASD_CQR_ERROR)
break;
/* Process requests with DASD_CQR_ERROR */
if (cqr->status == DASD_CQR_ERROR) {
if (cqr->irb.scsw.fctl & SCSW_FCTL_HALT_FUNC) {
cqr->status = DASD_CQR_FAILED;
cqr->stopclk = get_clock();
} else {
if (cqr->irb.esw.esw0.erw.cons) {
erp_fn = device->discipline->
erp_action(cqr);
erp_fn(cqr);
} else
dasd_default_erp_action(cqr);
}
goto restart;
}
/* Process finished ERP request. */
if (cqr->refers) {
__dasd_process_erp(device, cqr);
goto restart;
}
/* Rechain finished requests to final queue */
cqr->endclk = get_clock();
list_move_tail(&cqr->list, final_queue);
}
}
static void
dasd_end_request_cb(struct dasd_ccw_req * cqr, void *data)
{
struct request *req;
struct dasd_device *device;
int status;
req = (struct request *) data;
device = cqr->device;
dasd_profile_end(device, cqr, req);
status = cqr->device->discipline->free_cp(cqr,req);
spin_lock_irq(&device->request_queue_lock);
dasd_end_request(req, status);
spin_unlock_irq(&device->request_queue_lock);
}
/*
* Fetch requests from the block device queue.
*/
static inline void
__dasd_process_blk_queue(struct dasd_device * device)
{
request_queue_t *queue;
struct request *req;
struct dasd_ccw_req *cqr;
int nr_queued;
queue = device->request_queue;
/* No queue ? Then there is nothing to do. */
if (queue == NULL)
return;
/*
* We requeue request from the block device queue to the ccw
* queue only in two states. In state DASD_STATE_READY the
* partition detection is done and we need to requeue requests
* for that. State DASD_STATE_ONLINE is normal block device
* operation.
*/
if (device->state != DASD_STATE_READY &&
device->state != DASD_STATE_ONLINE)
return;
nr_queued = 0;
/* Now we try to fetch requests from the request queue */
list_for_each_entry(cqr, &device->ccw_queue, list)
if (cqr->status == DASD_CQR_QUEUED)
nr_queued++;
while (!blk_queue_plugged(queue) &&
elv_next_request(queue) &&
nr_queued < DASD_CHANQ_MAX_SIZE) {
req = elv_next_request(queue);
if (device->features & DASD_FEATURE_READONLY &&
rq_data_dir(req) == WRITE) {
DBF_DEV_EVENT(DBF_ERR, device,
"Rejecting write request %p",
req);
blkdev_dequeue_request(req);
dasd_end_request(req, 0);
continue;
}
if (device->stopped & DASD_STOPPED_DC_EIO) {
blkdev_dequeue_request(req);
dasd_end_request(req, 0);
continue;
}
cqr = device->discipline->build_cp(device, req);
if (IS_ERR(cqr)) {
if (PTR_ERR(cqr) == -ENOMEM)
break; /* terminate request queue loop */
DBF_DEV_EVENT(DBF_ERR, device,
"CCW creation failed (rc=%ld) "
"on request %p",
PTR_ERR(cqr), req);
blkdev_dequeue_request(req);
dasd_end_request(req, 0);
continue;
}
cqr->callback = dasd_end_request_cb;
cqr->callback_data = (void *) req;
cqr->status = DASD_CQR_QUEUED;
blkdev_dequeue_request(req);
list_add_tail(&cqr->list, &device->ccw_queue);
dasd_profile_start(device, cqr, req);
nr_queued++;
}
}
/*
* Take a look at the first request on the ccw queue and check
* if it reached its expire time. If so, terminate the IO.
*/
static inline void
__dasd_check_expire(struct dasd_device * device)
{
struct dasd_ccw_req *cqr;
if (list_empty(&device->ccw_queue))
return;
cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
if (cqr->status == DASD_CQR_IN_IO && cqr->expires != 0) {
if (time_after_eq(jiffies, cqr->expires + cqr->starttime)) {
if (device->discipline->term_IO(cqr) != 0)
/* Hmpf, try again in 1/10 sec */
dasd_set_timer(device, 10);
}
}
}
/*
* Take a look at the first request on the ccw queue and check
* if it needs to be started.
*/
static inline void
__dasd_start_head(struct dasd_device * device)
{
struct dasd_ccw_req *cqr;
int rc;
if (list_empty(&device->ccw_queue))
return;
cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
/* check FAILFAST */
if (device->stopped & ~DASD_STOPPED_PENDING &&
test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags)) {
cqr->status = DASD_CQR_FAILED;
dasd_schedule_bh(device);
}
if ((cqr->status == DASD_CQR_QUEUED) &&
(!device->stopped)) {
/* try to start the first I/O that can be started */
rc = device->discipline->start_IO(cqr);
if (rc == 0)
dasd_set_timer(device, cqr->expires);
else if (rc == -EACCES) {
dasd_schedule_bh(device);
} else
/* Hmpf, try again in 1/2 sec */
dasd_set_timer(device, 50);
}
}
/*
* Remove requests from the ccw queue.
*/
static void
dasd_flush_ccw_queue(struct dasd_device * device, int all)
{
struct list_head flush_queue;
struct list_head *l, *n;
struct dasd_ccw_req *cqr;
INIT_LIST_HEAD(&flush_queue);
spin_lock_irq(get_ccwdev_lock(device->cdev));
list_for_each_safe(l, n, &device->ccw_queue) {
cqr = list_entry(l, struct dasd_ccw_req, list);
/* Flush all request or only block device requests? */
if (all == 0 && cqr->callback == dasd_end_request_cb)
continue;
if (cqr->status == DASD_CQR_IN_IO)
device->discipline->term_IO(cqr);
if (cqr->status != DASD_CQR_DONE ||
cqr->status != DASD_CQR_FAILED) {
cqr->status = DASD_CQR_FAILED;
cqr->stopclk = get_clock();
}
/* Process finished ERP request. */
if (cqr->refers) {
__dasd_process_erp(device, cqr);
continue;
}
/* Rechain request on device request queue */
cqr->endclk = get_clock();
list_move_tail(&cqr->list, &flush_queue);
}
spin_unlock_irq(get_ccwdev_lock(device->cdev));
/* Now call the callback function of flushed requests */
list_for_each_safe(l, n, &flush_queue) {
cqr = list_entry(l, struct dasd_ccw_req, list);
if (cqr->callback != NULL)
(cqr->callback)(cqr, cqr->callback_data);
}
}
/*
* Acquire the device lock and process queues for the device.
*/
static void
dasd_tasklet(struct dasd_device * device)
{
struct list_head final_queue;
struct list_head *l, *n;
struct dasd_ccw_req *cqr;
atomic_set (&device->tasklet_scheduled, 0);
INIT_LIST_HEAD(&final_queue);
spin_lock_irq(get_ccwdev_lock(device->cdev));
/* Check expire time of first request on the ccw queue. */
__dasd_check_expire(device);
/* Finish off requests on ccw queue */
__dasd_process_ccw_queue(device, &final_queue);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
/* Now call the callback function of requests with final status */
list_for_each_safe(l, n, &final_queue) {
cqr = list_entry(l, struct dasd_ccw_req, list);
list_del_init(&cqr->list);
if (cqr->callback != NULL)
(cqr->callback)(cqr, cqr->callback_data);
}
spin_lock_irq(&device->request_queue_lock);
spin_lock(get_ccwdev_lock(device->cdev));
/* Get new request from the block device request queue */
__dasd_process_blk_queue(device);
/* Now check if the head of the ccw queue needs to be started. */
__dasd_start_head(device);
spin_unlock(get_ccwdev_lock(device->cdev));
spin_unlock_irq(&device->request_queue_lock);
dasd_put_device(device);
}
/*
* Schedules a call to dasd_tasklet over the device tasklet.
*/
void
dasd_schedule_bh(struct dasd_device * device)
{
/* Protect against rescheduling. */
if (atomic_cmpxchg (&device->tasklet_scheduled, 0, 1) != 0)
return;
dasd_get_device(device);
tasklet_hi_schedule(&device->tasklet);
}
/*
* Queue a request to the head of the ccw_queue. Start the I/O if
* possible.
*/
void
dasd_add_request_head(struct dasd_ccw_req *req)
{
struct dasd_device *device;
unsigned long flags;
device = req->device;
spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
req->status = DASD_CQR_QUEUED;
req->device = device;
list_add(&req->list, &device->ccw_queue);
/* let the bh start the request to keep them in order */
dasd_schedule_bh(device);
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
}
/*
* Queue a request to the tail of the ccw_queue. Start the I/O if
* possible.
*/
void
dasd_add_request_tail(struct dasd_ccw_req *req)
{
struct dasd_device *device;
unsigned long flags;
device = req->device;
spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
req->status = DASD_CQR_QUEUED;
req->device = device;
list_add_tail(&req->list, &device->ccw_queue);
/* let the bh start the request to keep them in order */
dasd_schedule_bh(device);
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
}
/*
* Wakeup callback.
*/
static void
dasd_wakeup_cb(struct dasd_ccw_req *cqr, void *data)
{
wake_up((wait_queue_head_t *) data);
}
static inline int
_wait_for_wakeup(struct dasd_ccw_req *cqr)
{
struct dasd_device *device;
int rc;
device = cqr->device;
spin_lock_irq(get_ccwdev_lock(device->cdev));
rc = ((cqr->status == DASD_CQR_DONE ||
cqr->status == DASD_CQR_FAILED) &&
list_empty(&cqr->list));
spin_unlock_irq(get_ccwdev_lock(device->cdev));
return rc;
}
/*
* Attempts to start a special ccw queue and waits for its completion.
*/
int
dasd_sleep_on(struct dasd_ccw_req * cqr)
{
wait_queue_head_t wait_q;
struct dasd_device *device;
int rc;
device = cqr->device;
spin_lock_irq(get_ccwdev_lock(device->cdev));
init_waitqueue_head (&wait_q);
cqr->callback = dasd_wakeup_cb;
cqr->callback_data = (void *) &wait_q;
cqr->status = DASD_CQR_QUEUED;
list_add_tail(&cqr->list, &device->ccw_queue);
/* let the bh start the request to keep them in order */
dasd_schedule_bh(device);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
wait_event(wait_q, _wait_for_wakeup(cqr));
/* Request status is either done or failed. */
rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
return rc;
}
/*
* Attempts to start a special ccw queue and wait interruptible
* for its completion.
*/
int
dasd_sleep_on_interruptible(struct dasd_ccw_req * cqr)
{
wait_queue_head_t wait_q;
struct dasd_device *device;
int rc, finished;
device = cqr->device;
spin_lock_irq(get_ccwdev_lock(device->cdev));
init_waitqueue_head (&wait_q);
cqr->callback = dasd_wakeup_cb;
cqr->callback_data = (void *) &wait_q;
cqr->status = DASD_CQR_QUEUED;
list_add_tail(&cqr->list, &device->ccw_queue);
/* let the bh start the request to keep them in order */
dasd_schedule_bh(device);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
finished = 0;
while (!finished) {
rc = wait_event_interruptible(wait_q, _wait_for_wakeup(cqr));
if (rc != -ERESTARTSYS) {
/* Request is final (done or failed) */
rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
break;
}
spin_lock_irq(get_ccwdev_lock(device->cdev));
switch (cqr->status) {
case DASD_CQR_IN_IO:
/* terminate runnig cqr */
if (device->discipline->term_IO) {
cqr->retries = -1;
device->discipline->term_IO(cqr);
/*nished =
* wait (non-interruptible) for final status
* because signal ist still pending
*/
spin_unlock_irq(get_ccwdev_lock(device->cdev));
wait_event(wait_q, _wait_for_wakeup(cqr));
spin_lock_irq(get_ccwdev_lock(device->cdev));
rc = (cqr->status == DASD_CQR_DONE) ? 0 : -EIO;
finished = 1;
}
break;
case DASD_CQR_QUEUED:
/* request */
list_del_init(&cqr->list);
rc = -EIO;
finished = 1;
break;
default:
/* cqr with 'non-interruptable' status - just wait */
break;
}
spin_unlock_irq(get_ccwdev_lock(device->cdev));
}
return rc;
}
/*
* Whoa nelly now it gets really hairy. For some functions (e.g. steal lock
* for eckd devices) the currently running request has to be terminated
* and be put back to status queued, before the special request is added
* to the head of the queue. Then the special request is waited on normally.
*/
static inline int
_dasd_term_running_cqr(struct dasd_device *device)
{
struct dasd_ccw_req *cqr;
int rc;
if (list_empty(&device->ccw_queue))
return 0;
cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list);
rc = device->discipline->term_IO(cqr);
if (rc == 0) {
/* termination successful */
cqr->status = DASD_CQR_QUEUED;
cqr->startclk = cqr->stopclk = 0;
cqr->starttime = 0;
}
return rc;
}
int
dasd_sleep_on_immediatly(struct dasd_ccw_req * cqr)
{
wait_queue_head_t wait_q;
struct dasd_device *device;
int rc;
device = cqr->device;
spin_lock_irq(get_ccwdev_lock(device->cdev));
rc = _dasd_term_running_cqr(device);
if (rc) {
spin_unlock_irq(get_ccwdev_lock(device->cdev));
return rc;
}
init_waitqueue_head (&wait_q);
cqr->callback = dasd_wakeup_cb;
cqr->callback_data = (void *) &wait_q;
cqr->status = DASD_CQR_QUEUED;
list_add(&cqr->list, &device->ccw_queue);
/* let the bh start the request to keep them in order */
dasd_schedule_bh(device);
spin_unlock_irq(get_ccwdev_lock(device->cdev));
wait_event(wait_q, _wait_for_wakeup(cqr));
/* Request status is either done or failed. */
rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
return rc;
}
/*
* Cancels a request that was started with dasd_sleep_on_req.
* This is useful to timeout requests. The request will be
* terminated if it is currently in i/o.
* Returns 1 if the request has been terminated.
*/
int
dasd_cancel_req(struct dasd_ccw_req *cqr)
{
struct dasd_device *device = cqr->device;
unsigned long flags;
int rc;
rc = 0;
spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
switch (cqr->status) {
case DASD_CQR_QUEUED:
/* request was not started - just set to failed */
cqr->status = DASD_CQR_FAILED;
break;
case DASD_CQR_IN_IO:
/* request in IO - terminate IO and release again */
if (device->discipline->term_IO(cqr) != 0)
/* what to do if unable to terminate ??????
e.g. not _IN_IO */
cqr->status = DASD_CQR_FAILED;
cqr->stopclk = get_clock();
rc = 1;
break;
case DASD_CQR_DONE:
case DASD_CQR_FAILED:
/* already finished - do nothing */
break;
default:
DEV_MESSAGE(KERN_ALERT, device,
"invalid status %02x in request",
cqr->status);
BUG();
}
spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
dasd_schedule_bh(device);
return rc;
}
/*
* SECTION: Block device operations (request queue, partitions, open, release).
*/
/*
* Dasd request queue function. Called from ll_rw_blk.c
*/
static void
do_dasd_request(request_queue_t * queue)
{
struct dasd_device *device;
device = (struct dasd_device *) queue->queuedata;
spin_lock(get_ccwdev_lock(device->cdev));
/* Get new request from the block device request queue */
__dasd_process_blk_queue(device);
/* Now check if the head of the ccw queue needs to be started. */
__dasd_start_head(device);
spin_unlock(get_ccwdev_lock(device->cdev));
}
/*
* Allocate and initialize request queue and default I/O scheduler.
*/
static int
dasd_alloc_queue(struct dasd_device * device)
{
int rc;
device->request_queue = blk_init_queue(do_dasd_request,
&device->request_queue_lock);
if (device->request_queue == NULL)
return -ENOMEM;
device->request_queue->queuedata = device;
elevator_exit(device->request_queue->elevator);
rc = elevator_init(device->request_queue, "deadline");
if (rc) {
blk_cleanup_queue(device->request_queue);
return rc;
}
return 0;
}
/*
* Allocate and initialize request queue.
*/
static void
dasd_setup_queue(struct dasd_device * device)
{
int max;
blk_queue_hardsect_size(device->request_queue, device->bp_block);
max = device->discipline->max_blocks << device->s2b_shift;
blk_queue_max_sectors(device->request_queue, max);
blk_queue_max_phys_segments(device->request_queue, -1L);
blk_queue_max_hw_segments(device->request_queue, -1L);
blk_queue_max_segment_size(device->request_queue, -1L);
blk_queue_segment_boundary(device->request_queue, -1L);
blk_queue_ordered(device->request_queue, QUEUE_ORDERED_TAG, NULL);
}
/*
* Deactivate and free request queue.
*/
static void
dasd_free_queue(struct dasd_device * device)
{
if (device->request_queue) {
blk_cleanup_queue(device->request_queue);
device->request_queue = NULL;
}
}
/*
* Flush request on the request queue.
*/
static void
dasd_flush_request_queue(struct dasd_device * device)
{
struct request *req;
if (!device->request_queue)
return;
spin_lock_irq(&device->request_queue_lock);
while (!list_empty(&device->request_queue->queue_head)) {
req = elv_next_request(device->request_queue);
if (req == NULL)
break;
dasd_end_request(req, 0);
blkdev_dequeue_request(req);
}
spin_unlock_irq(&device->request_queue_lock);
}
static int
dasd_open(struct inode *inp, struct file *filp)
{
struct gendisk *disk = inp->i_bdev->bd_disk;
struct dasd_device *device = disk->private_data;
int rc;
atomic_inc(&device->open_count);
if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
rc = -ENODEV;
goto unlock;
}
if (!try_module_get(device->discipline->owner)) {
rc = -EINVAL;
goto unlock;
}
if (dasd_probeonly) {
DEV_MESSAGE(KERN_INFO, device, "%s",
"No access to device due to probeonly mode");
rc = -EPERM;
goto out;
}
if (device->state <= DASD_STATE_BASIC) {
DBF_DEV_EVENT(DBF_ERR, device, " %s",
" Cannot open unrecognized device");
rc = -ENODEV;
goto out;
}
return 0;
out:
module_put(device->discipline->owner);
unlock:
atomic_dec(&device->open_count);
return rc;
}
static int
dasd_release(struct inode *inp, struct file *filp)
{
struct gendisk *disk = inp->i_bdev->bd_disk;
struct dasd_device *device = disk->private_data;
atomic_dec(&device->open_count);
module_put(device->discipline->owner);
return 0;
}
/*
* Return disk geometry.
*/
static int
dasd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
struct dasd_device *device;
device = bdev->bd_disk->private_data;
if (!device)
return -ENODEV;
if (!device->discipline ||
!device->discipline->fill_geometry)
return -EINVAL;
device->discipline->fill_geometry(device, geo);
geo->start = get_start_sect(bdev) >> device->s2b_shift;
return 0;
}
struct block_device_operations
dasd_device_operations = {
.owner = THIS_MODULE,
.open = dasd_open,
.release = dasd_release,
.ioctl = dasd_ioctl,
.compat_ioctl = dasd_compat_ioctl,
.getgeo = dasd_getgeo,
};
static void
dasd_exit(void)
{
#ifdef CONFIG_PROC_FS
dasd_proc_exit();
#endif
dasd_ioctl_exit();
if (dasd_page_cache != NULL) {
kmem_cache_destroy(dasd_page_cache);
dasd_page_cache = NULL;
}
dasd_gendisk_exit();
dasd_devmap_exit();
devfs_remove("dasd");
if (dasd_debug_area != NULL) {
debug_unregister(dasd_debug_area);
dasd_debug_area = NULL;
}
}
/*
* SECTION: common functions for ccw_driver use
*/
/*
* Initial attempt at a probe function. this can be simplified once
* the other detection code is gone.
*/
int
dasd_generic_probe (struct ccw_device *cdev,
struct dasd_discipline *discipline)
{
int ret;
ret = dasd_add_sysfs_files(cdev);
if (ret) {
printk(KERN_WARNING
"dasd_generic_probe: could not add sysfs entries "
"for %s\n", cdev->dev.bus_id);
} else {
cdev->handler = &dasd_int_handler;
}
return ret;
}
/*
* This will one day be called from a global not_oper handler.
* It is also used by driver_unregister during module unload.
*/
void
dasd_generic_remove (struct ccw_device *cdev)
{
struct dasd_device *device;
cdev->handler = NULL;
dasd_remove_sysfs_files(cdev);
device = dasd_device_from_cdev(cdev);
if (IS_ERR(device))
return;
if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
/* Already doing offline processing */
dasd_put_device(device);
return;
}
/*
* This device is removed unconditionally. Set offline
* flag to prevent dasd_open from opening it while it is
* no quite down yet.
*/
dasd_set_target_state(device, DASD_STATE_NEW);
/* dasd_delete_device destroys the device reference. */
dasd_delete_device(device);
}
/*
* Activate a device. This is called from dasd_{eckd,fba}_probe() when either
* the device is detected for the first time and is supposed to be used
* or the user has started activation through sysfs.
*/
int
dasd_generic_set_online (struct ccw_device *cdev,
struct dasd_discipline *base_discipline)
{
struct dasd_discipline *discipline;
struct dasd_device *device;
int rc;
device = dasd_create_device(cdev);
if (IS_ERR(device))
return PTR_ERR(device);
discipline = base_discipline;
if (device->features & DASD_FEATURE_USEDIAG) {
if (!dasd_diag_discipline_pointer) {
printk (KERN_WARNING
"dasd_generic couldn't online device %s "
"- discipline DIAG not available\n",
cdev->dev.bus_id);
dasd_delete_device(device);
return -ENODEV;
}
discipline = dasd_diag_discipline_pointer;
}
if (!try_module_get(base_discipline->owner)) {
dasd_delete_device(device);
return -EINVAL;
}
if (!try_module_get(discipline->owner)) {
module_put(base_discipline->owner);
dasd_delete_device(device);
return -EINVAL;
}
device->base_discipline = base_discipline;
device->discipline = discipline;
rc = discipline->check_device(device);
if (rc) {
printk (KERN_WARNING
"dasd_generic couldn't online device %s "
"with discipline %s rc=%i\n",
cdev->dev.bus_id, discipline->name, rc);
module_put(discipline->owner);
module_put(base_discipline->owner);
dasd_delete_device(device);
return rc;
}
dasd_set_target_state(device, DASD_STATE_ONLINE);
if (device->state <= DASD_STATE_KNOWN) {
printk (KERN_WARNING
"dasd_generic discipline not found for %s\n",
cdev->dev.bus_id);
rc = -ENODEV;
dasd_set_target_state(device, DASD_STATE_NEW);
dasd_delete_device(device);
} else
pr_debug("dasd_generic device %s found\n",
cdev->dev.bus_id);
/* FIXME: we have to wait for the root device but we don't want
* to wait for each single device but for all at once. */
wait_event(dasd_init_waitq, _wait_for_device(device));
dasd_put_device(device);
return rc;
}
int
dasd_generic_set_offline (struct ccw_device *cdev)
{
struct dasd_device *device;
int max_count;
device = dasd_device_from_cdev(cdev);
if (IS_ERR(device))
return PTR_ERR(device);
if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
/* Already doing offline processing */
dasd_put_device(device);
return 0;
}
/*
* We must make sure that this device is currently not in use.
* The open_count is increased for every opener, that includes
* the blkdev_get in dasd_scan_partitions. We are only interested
* in the other openers.
*/
max_count = device->bdev ? 0 : -1;
if (atomic_read(&device->open_count) > max_count) {
printk (KERN_WARNING "Can't offline dasd device with open"
" count = %i.\n",
atomic_read(&device->open_count));
clear_bit(DASD_FLAG_OFFLINE, &device->flags);
dasd_put_device(device);
return -EBUSY;
}
dasd_set_target_state(device, DASD_STATE_NEW);
/* dasd_delete_device destroys the device reference. */
dasd_delete_device(device);
return 0;
}
int
dasd_generic_notify(struct ccw_device *cdev, int event)
{
struct dasd_device *device;
struct dasd_ccw_req *cqr;
unsigned long flags;
int ret;
device = dasd_device_from_cdev(cdev);
if (IS_ERR(device))
return 0;
spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
ret = 0;
switch (event) {
case CIO_GONE:
case CIO_NO_PATH:
if (device->state < DASD_STATE_BASIC)
break;
/* Device is active. We want to keep it. */
if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
list_for_each_entry(cqr, &device->ccw_queue, list)
if (cqr->status == DASD_CQR_IN_IO)
cqr->status = DASD_CQR_FAILED;
device->stopped |= DASD_STOPPED_DC_EIO;
} else {
list_for_each_entry(cqr, &device->ccw_queue, list)
if (cqr->status == DASD_CQR_IN_IO) {
cqr->status = DASD_CQR_QUEUED;
cqr->retries++;
}
device->stopped |= DASD_STOPPED_DC_WAIT;
dasd_set_timer(device, 0);
}
dasd_schedule_bh(device);
ret = 1;
break;
case CIO_OPER:
/* FIXME: add a sanity check. */
device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
dasd_schedule_bh(device);
ret = 1;
break;
}
spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
dasd_put_device(device);
return ret;
}
/*
* Automatically online either all dasd devices (dasd_autodetect) or
* all devices specified with dasd= parameters.
*/
static int
__dasd_auto_online(struct device *dev, void *data)
{
struct ccw_device *cdev;
cdev = to_ccwdev(dev);
if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
ccw_device_set_online(cdev);
return 0;
}
void
dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
{
struct device_driver *drv;
drv = get_driver(&dasd_discipline_driver->driver);
driver_for_each_device(drv, NULL, NULL, __dasd_auto_online);
put_driver(drv);
}
static int __init
dasd_init(void)
{
int rc;
init_waitqueue_head(&dasd_init_waitq);
/* register 'common' DASD debug area, used for all DBF_XXX calls */
dasd_debug_area = debug_register("dasd", 1, 2, 8 * sizeof (long));
if (dasd_debug_area == NULL) {
rc = -ENOMEM;
goto failed;
}
debug_register_view(dasd_debug_area, &debug_sprintf_view);
debug_set_level(dasd_debug_area, DBF_EMERG);
DBF_EVENT(DBF_EMERG, "%s", "debug area created");
dasd_diag_discipline_pointer = NULL;
rc = devfs_mk_dir("dasd");
if (rc)
goto failed;
rc = dasd_devmap_init();
if (rc)
goto failed;
rc = dasd_gendisk_init();
if (rc)
goto failed;
rc = dasd_parse();
if (rc)
goto failed;
rc = dasd_ioctl_init();
if (rc)
goto failed;
#ifdef CONFIG_PROC_FS
rc = dasd_proc_init();
if (rc)
goto failed;
#endif
return 0;
failed:
MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
dasd_exit();
return rc;
}
module_init(dasd_init);
module_exit(dasd_exit);
EXPORT_SYMBOL(dasd_debug_area);
EXPORT_SYMBOL(dasd_diag_discipline_pointer);
EXPORT_SYMBOL(dasd_add_request_head);
EXPORT_SYMBOL(dasd_add_request_tail);
EXPORT_SYMBOL(dasd_cancel_req);
EXPORT_SYMBOL(dasd_clear_timer);
EXPORT_SYMBOL(dasd_enable_device);
EXPORT_SYMBOL(dasd_int_handler);
EXPORT_SYMBOL(dasd_kfree_request);
EXPORT_SYMBOL(dasd_kick_device);
EXPORT_SYMBOL(dasd_kmalloc_request);
EXPORT_SYMBOL(dasd_schedule_bh);
EXPORT_SYMBOL(dasd_set_target_state);
EXPORT_SYMBOL(dasd_set_timer);
EXPORT_SYMBOL(dasd_sfree_request);
EXPORT_SYMBOL(dasd_sleep_on);
EXPORT_SYMBOL(dasd_sleep_on_immediatly);
EXPORT_SYMBOL(dasd_sleep_on_interruptible);
EXPORT_SYMBOL(dasd_smalloc_request);
EXPORT_SYMBOL(dasd_start_IO);
EXPORT_SYMBOL(dasd_term_IO);
EXPORT_SYMBOL_GPL(dasd_generic_probe);
EXPORT_SYMBOL_GPL(dasd_generic_remove);
EXPORT_SYMBOL_GPL(dasd_generic_notify);
EXPORT_SYMBOL_GPL(dasd_generic_set_online);
EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
EXPORT_SYMBOL_GPL(dasd_generic_auto_online);
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-indent-level: 4
* c-brace-imaginary-offset: 0
* c-brace-offset: -4
* c-argdecl-indent: 4
* c-label-offset: -4
* c-continued-statement-offset: 4
* c-continued-brace-offset: 0
* indent-tabs-mode: 1
* tab-width: 8
* End:
*/
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