static int ca_load(struct count_array *ca, struct dm_space_map *sm)
{
int r;
uint32_t count;
dm_block_t nr_blocks, i;
r = dm_sm_get_nr_blocks(sm, &nr_blocks);
if (r)
return r;
BUG_ON(ca->nr != nr_blocks);
DMWARN("Loading debug space map from disk. This may take some time");
for (i = 0; i < nr_blocks; i++) {
r = dm_sm_get_count(sm, i, &count);
if (r) {
DMERR("load failed");
return r;
}
ca_set_count(ca, i, count);
}
DMWARN("Load complete");
return 0;
}
/*
* get_type
* @type_name
*
* Attempt to retrieve the dm_dirty_log_type by name. If not already
* available, attempt to load the appropriate module.
*
* Log modules are named "dm-log-" followed by the 'type_name'.
* Modules may contain multiple types.
* This function will first try the module "dm-log-<type_name>",
* then truncate 'type_name' on the last '-' and try again.
*
* For example, if type_name was "clustered-disk", it would search
* 'dm-log-clustered-disk' then 'dm-log-clustered'.
*
* Returns: dirty_log_type* on success, NULL on failure
*/
static struct dm_dirty_log_type *get_type(const char *type_name)
{
char *p, *type_name_dup;
struct dm_dirty_log_type *log_type;
if (!type_name)
return NULL;
log_type = _get_dirty_log_type(type_name);
if (log_type)
return log_type;
type_name_dup = kstrdup(type_name, GFP_KERNEL);
if (!type_name_dup) {
DMWARN("No memory left to attempt log module load for \"%s\"",
type_name);
return NULL;
}
while (request_module("dm-log-%s", type_name_dup) ||
!(log_type = _get_dirty_log_type(type_name))) {
p = strrchr(type_name_dup, '-');
if (!p)
break;
p[0] = '\0';
}
if (!log_type)
DMWARN("Module for logging type \"%s\" not found.", type_name);
kfree(type_name_dup);
return log_type;
}
static int persistent_read_metadata(struct exception_store *store)
{
int r, new_snapshot;
struct pstore *ps = get_info(store);
/*
* Read the snapshot header.
*/
r = read_header(ps, &new_snapshot);
if (r)
return r;
/*
* Do we need to setup a new snapshot ?
*/
if (new_snapshot) {
r = write_header(ps);
if (r) {
DMWARN("write_header failed");
return r;
}
r = zero_area(ps, 0);
if (r) {
DMWARN("zero_area(0) failed");
return r;
}
} else {
/*
* Sanity checks.
*/
if (!ps->valid) {
DMWARN("snapshot is marked invalid");
return -EINVAL;
}
if (ps->version != SNAPSHOT_DISK_VERSION) {
DMWARN("unable to handle snapshot disk version %d",
ps->version);
return -EINVAL;
}
/*
* Read the metadata.
*/
r = read_exceptions(ps);
if (r)
return r;
}
return 0;
}
static int disk_resume(struct dirty_log *log)
{
int r = 0;
unsigned i;
struct log_c *lc = (struct log_c *) log->context;
size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
/*
* Read the disk header, but only if we know it is good.
* Assume the worst in the event of failure.
*/
if (!lc->log_dev_failed && (r = read_header(lc))) {
DMWARN("Read %s failed on mirror log device, %s.",
r ? "header" : "bits", lc->log_dev->name);
fail_log_device(lc);
lc->header.nr_regions = 0;
}
/* set or clear any new bits -- device has grown */
if (lc->sync == NOSYNC)
for (i = lc->header.nr_regions; i < lc->region_count; i++)
/* FIXME: amazingly inefficient */
log_set_bit(lc, lc->clean_bits, i);
else
for (i = lc->header.nr_regions; i < lc->region_count; i++)
/* FIXME: amazingly inefficient */
log_clear_bit(lc, lc->clean_bits, i);
/* clear any old bits if device has shrunk */
for (i = lc->region_count; i % 32; i++)
log_clear_bit(lc, lc->clean_bits, i);
/* copy clean across to sync */
memcpy(lc->sync_bits, lc->clean_bits, size);
lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
lc->sync_search = 0;
/* set the correct number of regions in the header */
lc->header.nr_regions = lc->region_count;
/* write out the log */
if ((r = write_header(lc))) {
DMWARN("Write header failed on mirror log device, %s.",
lc->log_dev->name);
fail_log_device(lc);
} else
restore_log_device(lc);
return r;
}
static int build_constructor_string(struct dm_target *ti,
unsigned argc, char **argv,
char **ctr_str)
{
int i, str_size;
char *str = NULL;
*ctr_str = NULL;
/*
* Determine overall size of the string.
*/
for (i = 0, str_size = 0; i < argc; i++)
str_size += strlen(argv[i]) + 1; /* +1 for space between args */
str_size += 20; /* Max number of chars in a printed u64 number */
str = kzalloc(str_size, GFP_KERNEL);
if (!str) {
DMWARN("Unable to allocate memory for constructor string");
return -ENOMEM;
}
str_size = sprintf(str, "%llu", (unsigned long long)ti->len);
for (i = 0; i < argc; i++)
str_size += sprintf(str + str_size, " %s", argv[i]);
*ctr_str = str;
return str_size;
}
static int read_header(struct log_c *log)
{
int r;
r = rw_header(log, READ);
if (r)
return r;
header_from_disk(&log->header, log->disk_header);
/* New log required? */
if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
log->header.magic = MIRROR_MAGIC;
log->header.version = MIRROR_DISK_VERSION;
log->header.nr_regions = 0;
}
/* Version 2 is like version 1 but always little endian on disk. */
#ifdef __LITTLE_ENDIAN
if (log->header.version == 1)
log->header.version = 2;
#endif
if (log->header.version != MIRROR_DISK_VERSION) {
DMWARN("incompatible disk log version");
return -EINVAL;
}
return 0;
}
static int __init dm_dirty_log_init(void)
{
int r;
r = dm_dirty_log_type_register(&_core_type);
if (r)
DMWARN("couldn't register core log");
r = dm_dirty_log_type_register(&_disk_type);
if (r) {
DMWARN("couldn't register disk type");
dm_dirty_log_type_unregister(&_core_type);
}
return r;
}
static int read_header(struct pstore *ps, int *new_snapshot)
{
int r;
struct disk_header *dh;
r = chunk_io(ps, 0, READ);
if (r)
return r;
dh = (struct disk_header *) ps->area;
if (le32_to_cpu(dh->magic) == 0) {
*new_snapshot = 1;
} else if (le32_to_cpu(dh->magic) == SNAP_MAGIC) {
*new_snapshot = 0;
ps->valid = le32_to_cpu(dh->valid);
ps->version = le32_to_cpu(dh->version);
ps->chunk_size = le32_to_cpu(dh->chunk_size);
} else {
DMWARN("Invalid/corrupt snapshot");
r = -ENXIO;
}
return r;
}
static void table_destroy(struct dm_table *t)
{
unsigned int i;
/* free the indexes (see dm_table_complete) */
if (t->depth >= 2)
vfree(t->index[t->depth - 2]);
/* free the targets */
for (i = 0; i < t->num_targets; i++) {
struct dm_target *tgt = t->targets + i;
if (tgt->type->dtr)
tgt->type->dtr(tgt);
dm_put_target_type(tgt->type);
}
vfree(t->highs);
/* free the device list */
if (t->devices.next != &t->devices) {
DMWARN("devices still present during destroy: "
"dm_table_remove_device calls missing");
free_devices(&t->devices);
}
kfree(t);
}
static int read_header(struct log_c *log)
{
int r;
unsigned long ebits;
r = dm_io_sync_vm(1, &log->header_location, READ,
log->disk_header, &ebits);
if (r)
return r;
header_from_disk(&log->header, log->disk_header);
/* New log required? */
if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
log->header.magic = MIRROR_MAGIC;
log->header.version = MIRROR_DISK_VERSION;
log->header.nr_regions = 0;
}
#ifdef __LITTLE_ENDIAN
if (log->header.version == 1)
log->header.version = 2;
#endif
if (log->header.version != MIRROR_DISK_VERSION) {
DMWARN("incompatible disk log version");
return -EINVAL;
}
return 0;
}
/*
* Functions to lock and unlock any filesystem running on the
* device.
*/
static int lock_fs(struct mapped_device *md)
{
int r = -ENOMEM;
md->frozen_bdev = bdget_disk(md->disk, 0);
if (!md->frozen_bdev) {
DMWARN("bdget failed in lock_fs");
goto out;
}
WARN_ON(md->frozen_sb);
md->frozen_sb = freeze_bdev(md->frozen_bdev);
if (IS_ERR(md->frozen_sb)) {
r = PTR_ERR(md->frozen_sb);
goto out_bdput;
}
/* don't bdput right now, we don't want the bdev
* to go away while it is locked. We'll bdput
* in unlock_fs
*/
return 0;
out_bdput:
bdput(md->frozen_bdev);
md->frozen_sb = NULL;
md->frozen_bdev = NULL;
out:
return r;
}
/*
* hp_sw_end_io - Completion handler for HP path activation.
* @req: path activation request
* @error: scsi-ml error
*
* Check sense data, free request structure, and notify dm that
* pg initialization has completed.
*
* Context: scsi-ml softirq
*
*/
static void hp_sw_end_io(struct request *req, int error)
{
struct dm_path *path = req->end_io_data;
unsigned err_flags = 0;
if (!error) {
DMDEBUG("%s path activation command - success",
path->dev->name);
goto out;
}
if (hp_sw_error_is_retryable(req)) {
DMDEBUG("%s path activation command - retry",
path->dev->name);
err_flags = MP_RETRY;
goto out;
}
DMWARN("%s path activation fail - error=0x%x",
path->dev->name, error);
err_flags = MP_FAIL_PATH;
out:
req->end_io_data = NULL;
__blk_put_request(req->q, req);
dm_pg_init_complete(path, err_flags);
}
static void dm_done(struct request *clone, int error, bool mapped)
{
int r = error;
struct dm_rq_target_io *tio = clone->end_io_data;
dm_request_endio_fn rq_end_io = NULL;
if (tio->ti) {
rq_end_io = tio->ti->type->rq_end_io;
if (mapped && rq_end_io)
r = rq_end_io(tio->ti, clone, error, &tio->info);
}
if (unlikely(r == -EREMOTEIO && (clone->cmd_flags & REQ_WRITE_SAME) &&
!clone->q->limits.max_write_same_sectors))
disable_write_same(tio->md);
if (r <= 0)
/* The target wants to complete the I/O */
dm_end_request(clone, r);
else if (r == DM_ENDIO_INCOMPLETE)
/* The target will handle the I/O */
return;
else if (r == DM_ENDIO_REQUEUE)
/* The target wants to requeue the I/O */
dm_requeue_original_request(tio->md, tio->orig);
else {
DMWARN("unimplemented target endio return value: %d", r);
BUG();
}
}
/**ltl
* 功能: 将目标设备加入到列表中
* 参数: t ->映射表
* ti ->映射目标
* path ->映射目标<major:minor>
* start-> 映射目标相对低层设备的起始偏移量(类似磁盘分区的起始地址)
* len -> 此目标设备在dm设备的长度
* mode -> rw
* result-> 底层设备对象
* 返回值:
* 说明:
*/
static int __table_get_device(struct dm_table *t, struct dm_target *ti,
const char *path, sector_t start, sector_t len,
int mode, struct dm_dev **result)
{
int r;
dev_t dev;
struct dm_dev *dd;
unsigned int major, minor;
BUG_ON(!t);
/* 获取主设备号和次设备号 */
if (sscanf(path, "%u:%u", &major, &minor) == 2) {
/* Extract the major/minor numbers */
dev = MKDEV(major, minor);
if (MAJOR(dev) != major || MINOR(dev) != minor)
return -EOVERFLOW;
} else {
/* convert the path to a device */
if ((r = lookup_device(path, &dev))) /* 根据设备路径/dev/sdb获取<major:minor> */
return r;
}
/* 在列表中查找映射目标 */
dd = find_device(&t->devices, dev);
if (!dd) {
dd = kmalloc(sizeof(*dd), GFP_KERNEL);
if (!dd)
return -ENOMEM;
dd->mode = mode;
dd->bdev = NULL;
/* 打开设备 */
if ((r = open_dev(dd, dev, t->md))) {
kfree(dd);
return r;
}
format_dev_t(dd->name, dev); /* 主设备号次设备号 */
atomic_set(&dd->count, 0);
/* 将目标设备插入到映射表中 */
list_add(&dd->list, &t->devices);
} else if (dd->mode != (mode | dd->mode)) {
r = upgrade_mode(dd, mode, t->md);
if (r)
return r;
}
atomic_inc(&dd->count);
/* 检查区域是否超过设备 */
if (!check_device_area(dd, start, len)) {
DMWARN("device %s too small for target", path);
dm_put_device(ti, dd);
return -EINVAL;
}
*result = dd;
return 0;
}
/*----------------------------------------------------------------
* disk log constructor/destructor
*
* argv contains log_device region_size followed optionally by [no]sync
*--------------------------------------------------------------*/
static int disk_ctr(struct dirty_log *log, struct dm_target *ti,
unsigned int argc, char **argv)
{
int r;
size_t size;
struct log_c *lc;
struct dm_dev *dev;
if (argc < 2 || argc > 3) {
DMWARN("wrong number of arguments to disk mirror log");
return -EINVAL;
}
r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
FMODE_READ | FMODE_WRITE, &dev);
if (r)
return r;
r = core_ctr(log, ti, argc - 1, argv + 1);
if (r) {
dm_put_device(ti, dev);
return r;
}
lc = (struct log_c *) log->context;
lc->log_dev = dev;
/* setup the disk header fields */
lc->header_location.bdev = lc->log_dev->bdev;
lc->header_location.sector = 0;
lc->header_location.count = 1;
/*
* We can't read less than this amount, even though we'll
* not be using most of this space.
*/
lc->disk_header = vmalloc(1 << SECTOR_SHIFT);
if (!lc->disk_header)
goto bad;
/* setup the disk bitset fields */
lc->bits_location.bdev = lc->log_dev->bdev;
lc->bits_location.sector = LOG_OFFSET;
size = dm_round_up(lc->bitset_uint32_count * sizeof(uint32_t),
1 << SECTOR_SHIFT);
lc->bits_location.count = size >> SECTOR_SHIFT;
lc->disk_bits = vmalloc(size);
if (!lc->disk_bits) {
vfree(lc->disk_header);
goto bad;
}
return 0;
bad:
dm_put_device(ti, lc->log_dev);
core_dtr(log);
return -ENOMEM;
}
static void persistent_drop(struct exception_store *store)
{
struct pstore *ps = get_info(store);
ps->valid = 0;
if (write_header(ps))
DMWARN("write header failed");
}
/*
* Add a device to the list, or just increment the usage count if
* it's already present.
*/
static int __table_get_device(struct dm_table *t, struct dm_target *ti,
const char *path, sector_t start, sector_t len,
int mode, struct dm_dev **result)
{
int r;
dev_t dev;
struct dm_dev *dd;
unsigned int major, minor;
if (!t)
BUG();
if (sscanf(path, "%u:%u", &major, &minor) == 2) {
/* Extract the major/minor numbers */
dev = MKDEV(major, minor);
if (MAJOR(dev) != major || MINOR(dev) != minor)
return -EOVERFLOW;
} else {
/* convert the path to a device */
if ((r = lookup_device(path, &dev)))
return r;
}
dd = find_device(&t->devices, dev);
if (!dd) {
dd = kmalloc(sizeof(*dd), GFP_KERNEL);
if (!dd)
return -ENOMEM;
dd->mode = mode;
dd->bdev = NULL;
if ((r = open_dev(dd, dev))) {
kfree(dd);
return r;
}
atomic_set(&dd->count, 0);
list_add(&dd->list, &t->devices);
} else if (dd->mode != (mode | dd->mode)) {
r = upgrade_mode(dd, mode);
if (r)
return r;
}
atomic_inc(&dd->count);
if (!check_device_area(dd, start, len)) {
DMWARN("device %s too small for target", path);
dm_put_device(ti, dd);
return -EINVAL;
}
*result = dd;
return 0;
}
/*
* Returns:
* DM_MAPIO_* : the request has been processed as indicated
* DM_MAPIO_REQUEUE : the original request needs to be immediately requeued
* < 0 : the request was completed due to failure
*/
static int map_request(struct dm_rq_target_io *tio)
{
int r;
struct dm_target *ti = tio->ti;
struct mapped_device *md = tio->md;
struct request *rq = tio->orig;
struct request *clone = NULL;
blk_status_t ret;
r = ti->type->clone_and_map_rq(ti, rq, &tio->info, &clone);
check_again:
switch (r) {
case DM_MAPIO_SUBMITTED:
/* The target has taken the I/O to submit by itself later */
break;
case DM_MAPIO_REMAPPED:
if (setup_clone(clone, rq, tio, GFP_ATOMIC)) {
/* -ENOMEM */
ti->type->release_clone_rq(clone);
return DM_MAPIO_REQUEUE;
}
/* The target has remapped the I/O so dispatch it */
trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)),
blk_rq_pos(rq));
ret = dm_dispatch_clone_request(clone, rq);
if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) {
blk_rq_unprep_clone(clone);
tio->ti->type->release_clone_rq(clone);
tio->clone = NULL;
if (!rq->q->mq_ops)
r = DM_MAPIO_DELAY_REQUEUE;
else
r = DM_MAPIO_REQUEUE;
goto check_again;
}
break;
case DM_MAPIO_REQUEUE:
/* The target wants to requeue the I/O */
break;
case DM_MAPIO_DELAY_REQUEUE:
/* The target wants to requeue the I/O after a delay */
dm_requeue_original_request(tio, true);
break;
case DM_MAPIO_KILL:
/* The target wants to complete the I/O */
dm_kill_unmapped_request(rq, BLK_STS_IOERR);
break;
default:
DMWARN("unimplemented target map return value: %d", r);
BUG();
}
return r;
}
/*
* Returns:
* 0 : the request has been processed
* DM_MAPIO_REQUEUE : the original request needs to be requeued
* < 0 : the request was completed due to failure
*/
static int map_request(struct dm_rq_target_io *tio, struct request *rq,
struct mapped_device *md)
{
int r;
struct dm_target *ti = tio->ti;
struct request *clone = NULL;
if (tio->clone) {
clone = tio->clone;
r = ti->type->map_rq(ti, clone, &tio->info);
} else {
r = ti->type->clone_and_map_rq(ti, rq, &tio->info, &clone);
if (r < 0) {
/* The target wants to complete the I/O */
dm_kill_unmapped_request(rq, r);
return r;
}
if (r != DM_MAPIO_REMAPPED)
return r;
if (setup_clone(clone, rq, tio, GFP_ATOMIC)) {
/* -ENOMEM */
ti->type->release_clone_rq(clone);
return DM_MAPIO_REQUEUE;
}
}
switch (r) {
case DM_MAPIO_SUBMITTED:
/* The target has taken the I/O to submit by itself later */
break;
case DM_MAPIO_REMAPPED:
/* The target has remapped the I/O so dispatch it */
trace_block_rq_remap(clone->q, clone, disk_devt(dm_disk(md)),
blk_rq_pos(rq));
dm_dispatch_clone_request(clone, rq);
break;
case DM_MAPIO_REQUEUE:
/* The target wants to requeue the I/O */
dm_requeue_original_request(md, tio->orig);
break;
default:
if (r > 0) {
DMWARN("unimplemented target map return value: %d", r);
BUG();
}
/* The target wants to complete the I/O */
dm_kill_unmapped_request(rq, r);
return r;
}
return 0;
}
int dm_unregister_dirty_log_type(struct dirty_log_type *type)
{
spin_lock(&_lock);
if (type->use_count)
DMWARN("Attempt to unregister a log type that is still in use");
else
list_del(&type->list);
spin_unlock(&_lock);
return 0;
}
/*
* Set the geometry of a device.
*/
int dm_set_geometry(struct mapped_device *md, struct hd_geometry *geo)
{
sector_t sz = (sector_t)geo->cylinders * geo->heads * geo->sectors;
if (geo->start > sz) {
DMWARN("Start sector is beyond the geometry limits.");
return -EINVAL;
}
md->geometry = *geo;
return 0;
}
int dm_unregister_dirty_log_type(struct dirty_log_type *type)
{
spin_lock(&_lock);
if (type->use_count)
DMWARN("Unregister failed: log type '%s' still in use",
type->name);
else
list_del(&type->list);
spin_unlock(&_lock);
return 0;
}
static struct dirty_log_type *get_type(const char *type_name)
{
struct dirty_log_type *type;
if ((type = _get_type(type_name)))
return type;
/* Logging type not found. Try to find module. */
if (load_log_module(type_name)) {
DMWARN("Module for logging type \"%s\" not found.", type_name);
return NULL;
}
return _get_type(type_name);
}
/*
* See if the device with a specific minor # is free.
*/
static int specific_minor(unsigned int minor)
{
int r = -EBUSY;
if (minor >= MAX_DEVICES) {
DMWARN("request for a mapped_device beyond MAX_DEVICES (%d)",
MAX_DEVICES);
return -EINVAL;
}
spin_lock(&_minor_lock);
if (!test_and_set_bit(minor, _minor_bits))
r = 0;
spin_unlock(&_minor_lock);
return r;
}
static void __map_bio(struct dm_target *ti, struct bio *clone,
struct target_io *tio)
{
int r;
sector_t sector;
struct mapped_device *md;
/*
* Sanity checks.
*/
BUG_ON(!clone->bi_size);
clone->bi_end_io = clone_endio;
clone->bi_private = tio;
/*
* Map the clone. If r == 0 we don't need to do
* anything, the target has assumed ownership of
* this io.
*/
atomic_inc(&tio->io->io_count);
sector = clone->bi_sector;
r = ti->type->map(ti, clone, &tio->info);
if (r == DM_MAPIO_REMAPPED) {
/* the bio has been remapped so dispatch it */
blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone,
tio->io->bio->bi_bdev->bd_dev, sector,
clone->bi_sector);
generic_make_request(clone);
} else if (r < 0 || r == DM_MAPIO_REQUEUE) {
/* error the io and bail out, or requeue it if needed */
md = tio->io->md;
dec_pending(tio->io, r);
/*
* Store bio_set for cleanup.
*/
clone->bi_private = md->bs;
bio_put(clone);
free_tio(md, tio);
} else if (r) {
DMWARN("unimplemented target map return value: %d", r);
BUG();
}
}
static int __unlock_fs(struct mapped_device *md)
{
struct block_device *bdev;
if (!test_and_clear_bit(DMF_FS_LOCKED, &md->flags))
return 0;
bdev = bdget_disk(md->disk, 0);
if (!bdev) {
DMWARN("bdget failed in __unlock_fs");
return -ENOMEM;
}
thaw_bdev(bdev, md->frozen_sb);
md->frozen_sb = NULL;
bdput(bdev);
bdput(bdev);
return 0;
}
static int flush_header(struct log_c *lc)
{
struct dm_io_region null_location = {
.bdev = lc->header_location.bdev,
.sector = 0,
.count = 0,
};
lc->io_req.bi_op = REQ_OP_WRITE;
lc->io_req.bi_op_flags = WRITE_FLUSH;
return dm_io(&lc->io_req, 1, &null_location, NULL);
}
static int read_header(struct log_c *log)
{
int r;
r = rw_header(log, REQ_OP_READ);
if (r)
return r;
header_from_disk(&log->header, log->disk_header);
/* New log required? */
if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
log->header.magic = MIRROR_MAGIC;
log->header.version = MIRROR_DISK_VERSION;
log->header.nr_regions = 0;
}
#ifdef __LITTLE_ENDIAN
if (log->header.version == 1)
log->header.version = 2;
#endif
if (log->header.version != MIRROR_DISK_VERSION) {
DMWARN("incompatible disk log version");
return -EINVAL;
}
return 0;
}
static void dm_done(struct request *clone, blk_status_t error, bool mapped)
{
int r = DM_ENDIO_DONE;
struct dm_rq_target_io *tio = clone->end_io_data;
dm_request_endio_fn rq_end_io = NULL;
if (tio->ti) {
rq_end_io = tio->ti->type->rq_end_io;
if (mapped && rq_end_io)
r = rq_end_io(tio->ti, clone, error, &tio->info);
}
if (unlikely(error == BLK_STS_TARGET)) {
if (req_op(clone) == REQ_OP_WRITE_SAME &&
!clone->q->limits.max_write_same_sectors)
disable_write_same(tio->md);
if (req_op(clone) == REQ_OP_WRITE_ZEROES &&
!clone->q->limits.max_write_zeroes_sectors)
disable_write_zeroes(tio->md);
}
switch (r) {
case DM_ENDIO_DONE:
/* The target wants to complete the I/O */
dm_end_request(clone, error);
break;
case DM_ENDIO_INCOMPLETE:
/* The target will handle the I/O */
return;
case DM_ENDIO_REQUEUE:
/* The target wants to requeue the I/O */
dm_requeue_original_request(tio, false);
break;
case DM_ENDIO_DELAY_REQUEUE:
/* The target wants to requeue the I/O after a delay */
dm_requeue_original_request(tio, true);
break;
default:
DMWARN("unimplemented target endio return value: %d", r);
BUG();
}
}
/*
* Called with the queue lock held.
*/
static int dm_old_prep_fn(struct request_queue *q, struct request *rq)
{
struct mapped_device *md = q->queuedata;
struct dm_rq_target_io *tio;
if (unlikely(rq->special)) {
DMWARN("Already has something in rq->special.");
return BLKPREP_KILL;
}
tio = dm_old_prep_tio(rq, md, GFP_ATOMIC);
if (!tio)
return BLKPREP_DEFER;
rq->special = tio;
rq->cmd_flags |= REQ_DONTPREP;
return BLKPREP_OK;
}
static int emc_create(struct hw_handler *hwh, unsigned argc, char **argv)
{
struct emc_handler *h;
unsigned hr, short_trespass;
if (argc == 0) {
/* No arguments: use defaults */
hr = 0;
short_trespass = 0;
} else if (argc != 2) {
DMWARN("dm-emc hwhandler: incorrect number of arguments");
return -EINVAL;
} else {
if ((sscanf(argv[0], "%u", &short_trespass) != 1)
|| (short_trespass > 1)) {
DMWARN("dm-emc: invalid trespass mode selected");
return -EINVAL;
}
if ((sscanf(argv[1], "%u", &hr) != 1)
|| (hr > 1)) {
DMWARN("dm-emc: invalid honor reservation flag selected");
return -EINVAL;
}
}
h = alloc_emc_handler();
if (!h)
return -ENOMEM;
hwh->context = h;
if ((h->short_trespass = short_trespass))
DMWARN("dm-emc: short trespass command will be send");
else
DMWARN("dm-emc: long trespass command will be send");
if ((h->hr = hr))
DMWARN("dm-emc: honor reservation bit will be set");
else
DMWARN("dm-emc: honor reservation bit will not be set (default)");
return 0;
}
