linux/drivers/md/dm-table.c
Mikulas Patocka 123d87d553 dm: make dm_table_find_target return NULL
Currently, if we pass too high sector number to dm_table_find_target, it
returns zeroed dm_target structure and callers test if the structure is
zeroed with the macro dm_target_is_valid.

However, returning NULL is common practice to indicate errors.

This patch refactors the dm code, so that dm_table_find_target returns
NULL and its callers test the returned value for NULL. The macro
dm_target_is_valid is deleted. In alloc_targets, we no longer allocate an
extra zeroed target.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-08-23 10:13:12 -04:00

2140 lines
51 KiB
C

/*
* Copyright (C) 2001 Sistina Software (UK) Limited.
* Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
#include "dm-core.h"
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/blkdev.h>
#include <linux/namei.h>
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/atomic.h>
#include <linux/blk-mq.h>
#include <linux/mount.h>
#include <linux/dax.h>
#define DM_MSG_PREFIX "table"
#define MAX_DEPTH 16
#define NODE_SIZE L1_CACHE_BYTES
#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
struct dm_table {
struct mapped_device *md;
enum dm_queue_mode type;
/* btree table */
unsigned int depth;
unsigned int counts[MAX_DEPTH]; /* in nodes */
sector_t *index[MAX_DEPTH];
unsigned int num_targets;
unsigned int num_allocated;
sector_t *highs;
struct dm_target *targets;
struct target_type *immutable_target_type;
bool integrity_supported:1;
bool singleton:1;
unsigned integrity_added:1;
/*
* Indicates the rw permissions for the new logical
* device. This should be a combination of FMODE_READ
* and FMODE_WRITE.
*/
fmode_t mode;
/* a list of devices used by this table */
struct list_head devices;
/* events get handed up using this callback */
void (*event_fn)(void *);
void *event_context;
struct dm_md_mempools *mempools;
struct list_head target_callbacks;
};
/*
* Similar to ceiling(log_size(n))
*/
static unsigned int int_log(unsigned int n, unsigned int base)
{
int result = 0;
while (n > 1) {
n = dm_div_up(n, base);
result++;
}
return result;
}
/*
* Calculate the index of the child node of the n'th node k'th key.
*/
static inline unsigned int get_child(unsigned int n, unsigned int k)
{
return (n * CHILDREN_PER_NODE) + k;
}
/*
* Return the n'th node of level l from table t.
*/
static inline sector_t *get_node(struct dm_table *t,
unsigned int l, unsigned int n)
{
return t->index[l] + (n * KEYS_PER_NODE);
}
/*
* Return the highest key that you could lookup from the n'th
* node on level l of the btree.
*/
static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
{
for (; l < t->depth - 1; l++)
n = get_child(n, CHILDREN_PER_NODE - 1);
if (n >= t->counts[l])
return (sector_t) - 1;
return get_node(t, l, n)[KEYS_PER_NODE - 1];
}
/*
* Fills in a level of the btree based on the highs of the level
* below it.
*/
static int setup_btree_index(unsigned int l, struct dm_table *t)
{
unsigned int n, k;
sector_t *node;
for (n = 0U; n < t->counts[l]; n++) {
node = get_node(t, l, n);
for (k = 0U; k < KEYS_PER_NODE; k++)
node[k] = high(t, l + 1, get_child(n, k));
}
return 0;
}
void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
{
unsigned long size;
void *addr;
/*
* Check that we're not going to overflow.
*/
if (nmemb > (ULONG_MAX / elem_size))
return NULL;
size = nmemb * elem_size;
addr = vzalloc(size);
return addr;
}
EXPORT_SYMBOL(dm_vcalloc);
/*
* highs, and targets are managed as dynamic arrays during a
* table load.
*/
static int alloc_targets(struct dm_table *t, unsigned int num)
{
sector_t *n_highs;
struct dm_target *n_targets;
/*
* Allocate both the target array and offset array at once.
*/
n_highs = (sector_t *) dm_vcalloc(num, sizeof(struct dm_target) +
sizeof(sector_t));
if (!n_highs)
return -ENOMEM;
n_targets = (struct dm_target *) (n_highs + num);
memset(n_highs, -1, sizeof(*n_highs) * num);
vfree(t->highs);
t->num_allocated = num;
t->highs = n_highs;
t->targets = n_targets;
return 0;
}
int dm_table_create(struct dm_table **result, fmode_t mode,
unsigned num_targets, struct mapped_device *md)
{
struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
if (!t)
return -ENOMEM;
INIT_LIST_HEAD(&t->devices);
INIT_LIST_HEAD(&t->target_callbacks);
if (!num_targets)
num_targets = KEYS_PER_NODE;
num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
if (!num_targets) {
kfree(t);
return -ENOMEM;
}
if (alloc_targets(t, num_targets)) {
kfree(t);
return -ENOMEM;
}
t->type = DM_TYPE_NONE;
t->mode = mode;
t->md = md;
*result = t;
return 0;
}
static void free_devices(struct list_head *devices, struct mapped_device *md)
{
struct list_head *tmp, *next;
list_for_each_safe(tmp, next, devices) {
struct dm_dev_internal *dd =
list_entry(tmp, struct dm_dev_internal, list);
DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
dm_device_name(md), dd->dm_dev->name);
dm_put_table_device(md, dd->dm_dev);
kfree(dd);
}
}
void dm_table_destroy(struct dm_table *t)
{
unsigned int i;
if (!t)
return;
/* free the indexes */
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 */
free_devices(&t->devices, t->md);
dm_free_md_mempools(t->mempools);
kfree(t);
}
/*
* See if we've already got a device in the list.
*/
static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
{
struct dm_dev_internal *dd;
list_for_each_entry (dd, l, list)
if (dd->dm_dev->bdev->bd_dev == dev)
return dd;
return NULL;
}
/*
* If possible, this checks an area of a destination device is invalid.
*/
static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q;
struct queue_limits *limits = data;
struct block_device *bdev = dev->bdev;
sector_t dev_size =
i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
unsigned short logical_block_size_sectors =
limits->logical_block_size >> SECTOR_SHIFT;
char b[BDEVNAME_SIZE];
/*
* Some devices exist without request functions,
* such as loop devices not yet bound to backing files.
* Forbid the use of such devices.
*/
q = bdev_get_queue(bdev);
if (!q || !q->make_request_fn) {
DMWARN("%s: %s is not yet initialised: "
"start=%llu, len=%llu, dev_size=%llu",
dm_device_name(ti->table->md), bdevname(bdev, b),
(unsigned long long)start,
(unsigned long long)len,
(unsigned long long)dev_size);
return 1;
}
if (!dev_size)
return 0;
if ((start >= dev_size) || (start + len > dev_size)) {
DMWARN("%s: %s too small for target: "
"start=%llu, len=%llu, dev_size=%llu",
dm_device_name(ti->table->md), bdevname(bdev, b),
(unsigned long long)start,
(unsigned long long)len,
(unsigned long long)dev_size);
return 1;
}
/*
* If the target is mapped to zoned block device(s), check
* that the zones are not partially mapped.
*/
if (bdev_zoned_model(bdev) != BLK_ZONED_NONE) {
unsigned int zone_sectors = bdev_zone_sectors(bdev);
if (start & (zone_sectors - 1)) {
DMWARN("%s: start=%llu not aligned to h/w zone size %u of %s",
dm_device_name(ti->table->md),
(unsigned long long)start,
zone_sectors, bdevname(bdev, b));
return 1;
}
/*
* Note: The last zone of a zoned block device may be smaller
* than other zones. So for a target mapping the end of a
* zoned block device with such a zone, len would not be zone
* aligned. We do not allow such last smaller zone to be part
* of the mapping here to ensure that mappings with multiple
* devices do not end up with a smaller zone in the middle of
* the sector range.
*/
if (len & (zone_sectors - 1)) {
DMWARN("%s: len=%llu not aligned to h/w zone size %u of %s",
dm_device_name(ti->table->md),
(unsigned long long)len,
zone_sectors, bdevname(bdev, b));
return 1;
}
}
if (logical_block_size_sectors <= 1)
return 0;
if (start & (logical_block_size_sectors - 1)) {
DMWARN("%s: start=%llu not aligned to h/w "
"logical block size %u of %s",
dm_device_name(ti->table->md),
(unsigned long long)start,
limits->logical_block_size, bdevname(bdev, b));
return 1;
}
if (len & (logical_block_size_sectors - 1)) {
DMWARN("%s: len=%llu not aligned to h/w "
"logical block size %u of %s",
dm_device_name(ti->table->md),
(unsigned long long)len,
limits->logical_block_size, bdevname(bdev, b));
return 1;
}
return 0;
}
/*
* This upgrades the mode on an already open dm_dev, being
* careful to leave things as they were if we fail to reopen the
* device and not to touch the existing bdev field in case
* it is accessed concurrently inside dm_table_any_congested().
*/
static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
struct mapped_device *md)
{
int r;
struct dm_dev *old_dev, *new_dev;
old_dev = dd->dm_dev;
r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
dd->dm_dev->mode | new_mode, &new_dev);
if (r)
return r;
dd->dm_dev = new_dev;
dm_put_table_device(md, old_dev);
return 0;
}
/*
* Convert the path to a device
*/
dev_t dm_get_dev_t(const char *path)
{
dev_t dev;
struct block_device *bdev;
bdev = lookup_bdev(path);
if (IS_ERR(bdev))
dev = name_to_dev_t(path);
else {
dev = bdev->bd_dev;
bdput(bdev);
}
return dev;
}
EXPORT_SYMBOL_GPL(dm_get_dev_t);
/*
* Add a device to the list, or just increment the usage count if
* it's already present.
*/
int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
struct dm_dev **result)
{
int r;
dev_t dev;
struct dm_dev_internal *dd;
struct dm_table *t = ti->table;
BUG_ON(!t);
dev = dm_get_dev_t(path);
if (!dev)
return -ENODEV;
dd = find_device(&t->devices, dev);
if (!dd) {
dd = kmalloc(sizeof(*dd), GFP_KERNEL);
if (!dd)
return -ENOMEM;
if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) {
kfree(dd);
return r;
}
refcount_set(&dd->count, 1);
list_add(&dd->list, &t->devices);
goto out;
} else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
r = upgrade_mode(dd, mode, t->md);
if (r)
return r;
}
refcount_inc(&dd->count);
out:
*result = dd->dm_dev;
return 0;
}
EXPORT_SYMBOL(dm_get_device);
static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct queue_limits *limits = data;
struct block_device *bdev = dev->bdev;
struct request_queue *q = bdev_get_queue(bdev);
char b[BDEVNAME_SIZE];
if (unlikely(!q)) {
DMWARN("%s: Cannot set limits for nonexistent device %s",
dm_device_name(ti->table->md), bdevname(bdev, b));
return 0;
}
if (bdev_stack_limits(limits, bdev, start) < 0)
DMWARN("%s: adding target device %s caused an alignment inconsistency: "
"physical_block_size=%u, logical_block_size=%u, "
"alignment_offset=%u, start=%llu",
dm_device_name(ti->table->md), bdevname(bdev, b),
q->limits.physical_block_size,
q->limits.logical_block_size,
q->limits.alignment_offset,
(unsigned long long) start << SECTOR_SHIFT);
limits->zoned = blk_queue_zoned_model(q);
return 0;
}
/*
* Decrement a device's use count and remove it if necessary.
*/
void dm_put_device(struct dm_target *ti, struct dm_dev *d)
{
int found = 0;
struct list_head *devices = &ti->table->devices;
struct dm_dev_internal *dd;
list_for_each_entry(dd, devices, list) {
if (dd->dm_dev == d) {
found = 1;
break;
}
}
if (!found) {
DMWARN("%s: device %s not in table devices list",
dm_device_name(ti->table->md), d->name);
return;
}
if (refcount_dec_and_test(&dd->count)) {
dm_put_table_device(ti->table->md, d);
list_del(&dd->list);
kfree(dd);
}
}
EXPORT_SYMBOL(dm_put_device);
/*
* Checks to see if the target joins onto the end of the table.
*/
static int adjoin(struct dm_table *table, struct dm_target *ti)
{
struct dm_target *prev;
if (!table->num_targets)
return !ti->begin;
prev = &table->targets[table->num_targets - 1];
return (ti->begin == (prev->begin + prev->len));
}
/*
* Used to dynamically allocate the arg array.
*
* We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
* process messages even if some device is suspended. These messages have a
* small fixed number of arguments.
*
* On the other hand, dm-switch needs to process bulk data using messages and
* excessive use of GFP_NOIO could cause trouble.
*/
static char **realloc_argv(unsigned *size, char **old_argv)
{
char **argv;
unsigned new_size;
gfp_t gfp;
if (*size) {
new_size = *size * 2;
gfp = GFP_KERNEL;
} else {
new_size = 8;
gfp = GFP_NOIO;
}
argv = kmalloc_array(new_size, sizeof(*argv), gfp);
if (argv && old_argv) {
memcpy(argv, old_argv, *size * sizeof(*argv));
*size = new_size;
}
kfree(old_argv);
return argv;
}
/*
* Destructively splits up the argument list to pass to ctr.
*/
int dm_split_args(int *argc, char ***argvp, char *input)
{
char *start, *end = input, *out, **argv = NULL;
unsigned array_size = 0;
*argc = 0;
if (!input) {
*argvp = NULL;
return 0;
}
argv = realloc_argv(&array_size, argv);
if (!argv)
return -ENOMEM;
while (1) {
/* Skip whitespace */
start = skip_spaces(end);
if (!*start)
break; /* success, we hit the end */
/* 'out' is used to remove any back-quotes */
end = out = start;
while (*end) {
/* Everything apart from '\0' can be quoted */
if (*end == '\\' && *(end + 1)) {
*out++ = *(end + 1);
end += 2;
continue;
}
if (isspace(*end))
break; /* end of token */
*out++ = *end++;
}
/* have we already filled the array ? */
if ((*argc + 1) > array_size) {
argv = realloc_argv(&array_size, argv);
if (!argv)
return -ENOMEM;
}
/* we know this is whitespace */
if (*end)
end++;
/* terminate the string and put it in the array */
*out = '\0';
argv[*argc] = start;
(*argc)++;
}
*argvp = argv;
return 0;
}
/*
* Impose necessary and sufficient conditions on a devices's table such
* that any incoming bio which respects its logical_block_size can be
* processed successfully. If it falls across the boundary between
* two or more targets, the size of each piece it gets split into must
* be compatible with the logical_block_size of the target processing it.
*/
static int validate_hardware_logical_block_alignment(struct dm_table *table,
struct queue_limits *limits)
{
/*
* This function uses arithmetic modulo the logical_block_size
* (in units of 512-byte sectors).
*/
unsigned short device_logical_block_size_sects =
limits->logical_block_size >> SECTOR_SHIFT;
/*
* Offset of the start of the next table entry, mod logical_block_size.
*/
unsigned short next_target_start = 0;
/*
* Given an aligned bio that extends beyond the end of a
* target, how many sectors must the next target handle?
*/
unsigned short remaining = 0;
struct dm_target *uninitialized_var(ti);
struct queue_limits ti_limits;
unsigned i;
/*
* Check each entry in the table in turn.
*/
for (i = 0; i < dm_table_get_num_targets(table); i++) {
ti = dm_table_get_target(table, i);
blk_set_stacking_limits(&ti_limits);
/* combine all target devices' limits */
if (ti->type->iterate_devices)
ti->type->iterate_devices(ti, dm_set_device_limits,
&ti_limits);
/*
* If the remaining sectors fall entirely within this
* table entry are they compatible with its logical_block_size?
*/
if (remaining < ti->len &&
remaining & ((ti_limits.logical_block_size >>
SECTOR_SHIFT) - 1))
break; /* Error */
next_target_start =
(unsigned short) ((next_target_start + ti->len) &
(device_logical_block_size_sects - 1));
remaining = next_target_start ?
device_logical_block_size_sects - next_target_start : 0;
}
if (remaining) {
DMWARN("%s: table line %u (start sect %llu len %llu) "
"not aligned to h/w logical block size %u",
dm_device_name(table->md), i,
(unsigned long long) ti->begin,
(unsigned long long) ti->len,
limits->logical_block_size);
return -EINVAL;
}
return 0;
}
int dm_table_add_target(struct dm_table *t, const char *type,
sector_t start, sector_t len, char *params)
{
int r = -EINVAL, argc;
char **argv;
struct dm_target *tgt;
if (t->singleton) {
DMERR("%s: target type %s must appear alone in table",
dm_device_name(t->md), t->targets->type->name);
return -EINVAL;
}
BUG_ON(t->num_targets >= t->num_allocated);
tgt = t->targets + t->num_targets;
memset(tgt, 0, sizeof(*tgt));
if (!len) {
DMERR("%s: zero-length target", dm_device_name(t->md));
return -EINVAL;
}
tgt->type = dm_get_target_type(type);
if (!tgt->type) {
DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
return -EINVAL;
}
if (dm_target_needs_singleton(tgt->type)) {
if (t->num_targets) {
tgt->error = "singleton target type must appear alone in table";
goto bad;
}
t->singleton = true;
}
if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
tgt->error = "target type may not be included in a read-only table";
goto bad;
}
if (t->immutable_target_type) {
if (t->immutable_target_type != tgt->type) {
tgt->error = "immutable target type cannot be mixed with other target types";
goto bad;
}
} else if (dm_target_is_immutable(tgt->type)) {
if (t->num_targets) {
tgt->error = "immutable target type cannot be mixed with other target types";
goto bad;
}
t->immutable_target_type = tgt->type;
}
if (dm_target_has_integrity(tgt->type))
t->integrity_added = 1;
tgt->table = t;
tgt->begin = start;
tgt->len = len;
tgt->error = "Unknown error";
/*
* Does this target adjoin the previous one ?
*/
if (!adjoin(t, tgt)) {
tgt->error = "Gap in table";
goto bad;
}
r = dm_split_args(&argc, &argv, params);
if (r) {
tgt->error = "couldn't split parameters (insufficient memory)";
goto bad;
}
r = tgt->type->ctr(tgt, argc, argv);
kfree(argv);
if (r)
goto bad;
t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
if (!tgt->num_discard_bios && tgt->discards_supported)
DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
dm_device_name(t->md), type);
return 0;
bad:
DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
dm_put_target_type(tgt->type);
return r;
}
/*
* Target argument parsing helpers.
*/
static int validate_next_arg(const struct dm_arg *arg,
struct dm_arg_set *arg_set,
unsigned *value, char **error, unsigned grouped)
{
const char *arg_str = dm_shift_arg(arg_set);
char dummy;
if (!arg_str ||
(sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
(*value < arg->min) ||
(*value > arg->max) ||
(grouped && arg_set->argc < *value)) {
*error = arg->error;
return -EINVAL;
}
return 0;
}
int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
unsigned *value, char **error)
{
return validate_next_arg(arg, arg_set, value, error, 0);
}
EXPORT_SYMBOL(dm_read_arg);
int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
unsigned *value, char **error)
{
return validate_next_arg(arg, arg_set, value, error, 1);
}
EXPORT_SYMBOL(dm_read_arg_group);
const char *dm_shift_arg(struct dm_arg_set *as)
{
char *r;
if (as->argc) {
as->argc--;
r = *as->argv;
as->argv++;
return r;
}
return NULL;
}
EXPORT_SYMBOL(dm_shift_arg);
void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
{
BUG_ON(as->argc < num_args);
as->argc -= num_args;
as->argv += num_args;
}
EXPORT_SYMBOL(dm_consume_args);
static bool __table_type_bio_based(enum dm_queue_mode table_type)
{
return (table_type == DM_TYPE_BIO_BASED ||
table_type == DM_TYPE_DAX_BIO_BASED ||
table_type == DM_TYPE_NVME_BIO_BASED);
}
static bool __table_type_request_based(enum dm_queue_mode table_type)
{
return table_type == DM_TYPE_REQUEST_BASED;
}
void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
{
t->type = type;
}
EXPORT_SYMBOL_GPL(dm_table_set_type);
/* validate the dax capability of the target device span */
int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
int blocksize = *(int *) data;
return generic_fsdax_supported(dev->dax_dev, dev->bdev, blocksize,
start, len);
}
/* Check devices support synchronous DAX */
static int device_dax_synchronous(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
return dev->dax_dev && dax_synchronous(dev->dax_dev);
}
bool dm_table_supports_dax(struct dm_table *t,
iterate_devices_callout_fn iterate_fn, int *blocksize)
{
struct dm_target *ti;
unsigned i;
/* Ensure that all targets support DAX. */
for (i = 0; i < dm_table_get_num_targets(t); i++) {
ti = dm_table_get_target(t, i);
if (!ti->type->direct_access)
return false;
if (!ti->type->iterate_devices ||
!ti->type->iterate_devices(ti, iterate_fn, blocksize))
return false;
}
return true;
}
static bool dm_table_does_not_support_partial_completion(struct dm_table *t);
struct verify_rq_based_data {
unsigned sq_count;
unsigned mq_count;
};
static int device_is_rq_based(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
struct verify_rq_based_data *v = data;
if (queue_is_mq(q))
v->mq_count++;
else
v->sq_count++;
return queue_is_mq(q);
}
static int dm_table_determine_type(struct dm_table *t)
{
unsigned i;
unsigned bio_based = 0, request_based = 0, hybrid = 0;
struct verify_rq_based_data v = {.sq_count = 0, .mq_count = 0};
struct dm_target *tgt;
struct list_head *devices = dm_table_get_devices(t);
enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
int page_size = PAGE_SIZE;
if (t->type != DM_TYPE_NONE) {
/* target already set the table's type */
if (t->type == DM_TYPE_BIO_BASED) {
/* possibly upgrade to a variant of bio-based */
goto verify_bio_based;
}
BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
BUG_ON(t->type == DM_TYPE_NVME_BIO_BASED);
goto verify_rq_based;
}
for (i = 0; i < t->num_targets; i++) {
tgt = t->targets + i;
if (dm_target_hybrid(tgt))
hybrid = 1;
else if (dm_target_request_based(tgt))
request_based = 1;
else
bio_based = 1;
if (bio_based && request_based) {
DMERR("Inconsistent table: different target types"
" can't be mixed up");
return -EINVAL;
}
}
if (hybrid && !bio_based && !request_based) {
/*
* The targets can work either way.
* Determine the type from the live device.
* Default to bio-based if device is new.
*/
if (__table_type_request_based(live_md_type))
request_based = 1;
else
bio_based = 1;
}
if (bio_based) {
verify_bio_based:
/* We must use this table as bio-based */
t->type = DM_TYPE_BIO_BASED;
if (dm_table_supports_dax(t, device_supports_dax, &page_size) ||
(list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
t->type = DM_TYPE_DAX_BIO_BASED;
} else {
/* Check if upgrading to NVMe bio-based is valid or required */
tgt = dm_table_get_immutable_target(t);
if (tgt && !tgt->max_io_len && dm_table_does_not_support_partial_completion(t)) {
t->type = DM_TYPE_NVME_BIO_BASED;
goto verify_rq_based; /* must be stacked directly on NVMe (blk-mq) */
} else if (list_empty(devices) && live_md_type == DM_TYPE_NVME_BIO_BASED) {
t->type = DM_TYPE_NVME_BIO_BASED;
}
}
return 0;
}
BUG_ON(!request_based); /* No targets in this table */
t->type = DM_TYPE_REQUEST_BASED;
verify_rq_based:
/*
* Request-based dm supports only tables that have a single target now.
* To support multiple targets, request splitting support is needed,
* and that needs lots of changes in the block-layer.
* (e.g. request completion process for partial completion.)
*/
if (t->num_targets > 1) {
DMERR("%s DM doesn't support multiple targets",
t->type == DM_TYPE_NVME_BIO_BASED ? "nvme bio-based" : "request-based");
return -EINVAL;
}
if (list_empty(devices)) {
int srcu_idx;
struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
/* inherit live table's type */
if (live_table)
t->type = live_table->type;
dm_put_live_table(t->md, srcu_idx);
return 0;
}
tgt = dm_table_get_immutable_target(t);
if (!tgt) {
DMERR("table load rejected: immutable target is required");
return -EINVAL;
} else if (tgt->max_io_len) {
DMERR("table load rejected: immutable target that splits IO is not supported");
return -EINVAL;
}
/* Non-request-stackable devices can't be used for request-based dm */
if (!tgt->type->iterate_devices ||
!tgt->type->iterate_devices(tgt, device_is_rq_based, &v)) {
DMERR("table load rejected: including non-request-stackable devices");
return -EINVAL;
}
if (v.sq_count > 0) {
DMERR("table load rejected: not all devices are blk-mq request-stackable");
return -EINVAL;
}
return 0;
}
enum dm_queue_mode dm_table_get_type(struct dm_table *t)
{
return t->type;
}
struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
{
return t->immutable_target_type;
}
struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
{
/* Immutable target is implicitly a singleton */
if (t->num_targets > 1 ||
!dm_target_is_immutable(t->targets[0].type))
return NULL;
return t->targets;
}
struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
{
struct dm_target *ti;
unsigned i;
for (i = 0; i < dm_table_get_num_targets(t); i++) {
ti = dm_table_get_target(t, i);
if (dm_target_is_wildcard(ti->type))
return ti;
}
return NULL;
}
bool dm_table_bio_based(struct dm_table *t)
{
return __table_type_bio_based(dm_table_get_type(t));
}
bool dm_table_request_based(struct dm_table *t)
{
return __table_type_request_based(dm_table_get_type(t));
}
static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
{
enum dm_queue_mode type = dm_table_get_type(t);
unsigned per_io_data_size = 0;
unsigned min_pool_size = 0;
struct dm_target *ti;
unsigned i;
if (unlikely(type == DM_TYPE_NONE)) {
DMWARN("no table type is set, can't allocate mempools");
return -EINVAL;
}
if (__table_type_bio_based(type))
for (i = 0; i < t->num_targets; i++) {
ti = t->targets + i;
per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
min_pool_size = max(min_pool_size, ti->num_flush_bios);
}
t->mempools = dm_alloc_md_mempools(md, type, t->integrity_supported,
per_io_data_size, min_pool_size);
if (!t->mempools)
return -ENOMEM;
return 0;
}
void dm_table_free_md_mempools(struct dm_table *t)
{
dm_free_md_mempools(t->mempools);
t->mempools = NULL;
}
struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
{
return t->mempools;
}
static int setup_indexes(struct dm_table *t)
{
int i;
unsigned int total = 0;
sector_t *indexes;
/* allocate the space for *all* the indexes */
for (i = t->depth - 2; i >= 0; i--) {
t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
total += t->counts[i];
}
indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
if (!indexes)
return -ENOMEM;
/* set up internal nodes, bottom-up */
for (i = t->depth - 2; i >= 0; i--) {
t->index[i] = indexes;
indexes += (KEYS_PER_NODE * t->counts[i]);
setup_btree_index(i, t);
}
return 0;
}
/*
* Builds the btree to index the map.
*/
static int dm_table_build_index(struct dm_table *t)
{
int r = 0;
unsigned int leaf_nodes;
/* how many indexes will the btree have ? */
leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
/* leaf layer has already been set up */
t->counts[t->depth - 1] = leaf_nodes;
t->index[t->depth - 1] = t->highs;
if (t->depth >= 2)
r = setup_indexes(t);
return r;
}
static bool integrity_profile_exists(struct gendisk *disk)
{
return !!blk_get_integrity(disk);
}
/*
* Get a disk whose integrity profile reflects the table's profile.
* Returns NULL if integrity support was inconsistent or unavailable.
*/
static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t)
{
struct list_head *devices = dm_table_get_devices(t);
struct dm_dev_internal *dd = NULL;
struct gendisk *prev_disk = NULL, *template_disk = NULL;
unsigned i;
for (i = 0; i < dm_table_get_num_targets(t); i++) {
struct dm_target *ti = dm_table_get_target(t, i);
if (!dm_target_passes_integrity(ti->type))
goto no_integrity;
}
list_for_each_entry(dd, devices, list) {
template_disk = dd->dm_dev->bdev->bd_disk;
if (!integrity_profile_exists(template_disk))
goto no_integrity;
else if (prev_disk &&
blk_integrity_compare(prev_disk, template_disk) < 0)
goto no_integrity;
prev_disk = template_disk;
}
return template_disk;
no_integrity:
if (prev_disk)
DMWARN("%s: integrity not set: %s and %s profile mismatch",
dm_device_name(t->md),
prev_disk->disk_name,
template_disk->disk_name);
return NULL;
}
/*
* Register the mapped device for blk_integrity support if the
* underlying devices have an integrity profile. But all devices may
* not have matching profiles (checking all devices isn't reliable
* during table load because this table may use other DM device(s) which
* must be resumed before they will have an initialized integity
* profile). Consequently, stacked DM devices force a 2 stage integrity
* profile validation: First pass during table load, final pass during
* resume.
*/
static int dm_table_register_integrity(struct dm_table *t)
{
struct mapped_device *md = t->md;
struct gendisk *template_disk = NULL;
/* If target handles integrity itself do not register it here. */
if (t->integrity_added)
return 0;
template_disk = dm_table_get_integrity_disk(t);
if (!template_disk)
return 0;
if (!integrity_profile_exists(dm_disk(md))) {
t->integrity_supported = true;
/*
* Register integrity profile during table load; we can do
* this because the final profile must match during resume.
*/
blk_integrity_register(dm_disk(md),
blk_get_integrity(template_disk));
return 0;
}
/*
* If DM device already has an initialized integrity
* profile the new profile should not conflict.
*/
if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
DMWARN("%s: conflict with existing integrity profile: "
"%s profile mismatch",
dm_device_name(t->md),
template_disk->disk_name);
return 1;
}
/* Preserve existing integrity profile */
t->integrity_supported = true;
return 0;
}
/*
* Prepares the table for use by building the indices,
* setting the type, and allocating mempools.
*/
int dm_table_complete(struct dm_table *t)
{
int r;
r = dm_table_determine_type(t);
if (r) {
DMERR("unable to determine table type");
return r;
}
r = dm_table_build_index(t);
if (r) {
DMERR("unable to build btrees");
return r;
}
r = dm_table_register_integrity(t);
if (r) {
DMERR("could not register integrity profile.");
return r;
}
r = dm_table_alloc_md_mempools(t, t->md);
if (r)
DMERR("unable to allocate mempools");
return r;
}
static DEFINE_MUTEX(_event_lock);
void dm_table_event_callback(struct dm_table *t,
void (*fn)(void *), void *context)
{
mutex_lock(&_event_lock);
t->event_fn = fn;
t->event_context = context;
mutex_unlock(&_event_lock);
}
void dm_table_event(struct dm_table *t)
{
/*
* You can no longer call dm_table_event() from interrupt
* context, use a bottom half instead.
*/
BUG_ON(in_interrupt());
mutex_lock(&_event_lock);
if (t->event_fn)
t->event_fn(t->event_context);
mutex_unlock(&_event_lock);
}
EXPORT_SYMBOL(dm_table_event);
inline sector_t dm_table_get_size(struct dm_table *t)
{
return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
}
EXPORT_SYMBOL(dm_table_get_size);
struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
{
if (index >= t->num_targets)
return NULL;
return t->targets + index;
}
/*
* Search the btree for the correct target.
*
* Caller should check returned pointer for NULL
* to trap I/O beyond end of device.
*/
struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
{
unsigned int l, n = 0, k = 0;
sector_t *node;
if (unlikely(sector >= dm_table_get_size(t)))
return NULL;
for (l = 0; l < t->depth; l++) {
n = get_child(n, k);
node = get_node(t, l, n);
for (k = 0; k < KEYS_PER_NODE; k++)
if (node[k] >= sector)
break;
}
return &t->targets[(KEYS_PER_NODE * n) + k];
}
static int count_device(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
unsigned *num_devices = data;
(*num_devices)++;
return 0;
}
/*
* Check whether a table has no data devices attached using each
* target's iterate_devices method.
* Returns false if the result is unknown because a target doesn't
* support iterate_devices.
*/
bool dm_table_has_no_data_devices(struct dm_table *table)
{
struct dm_target *ti;
unsigned i, num_devices;
for (i = 0; i < dm_table_get_num_targets(table); i++) {
ti = dm_table_get_target(table, i);
if (!ti->type->iterate_devices)
return false;
num_devices = 0;
ti->type->iterate_devices(ti, count_device, &num_devices);
if (num_devices)
return false;
}
return true;
}
static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
enum blk_zoned_model *zoned_model = data;
return q && blk_queue_zoned_model(q) == *zoned_model;
}
static bool dm_table_supports_zoned_model(struct dm_table *t,
enum blk_zoned_model zoned_model)
{
struct dm_target *ti;
unsigned i;
for (i = 0; i < dm_table_get_num_targets(t); i++) {
ti = dm_table_get_target(t, i);
if (zoned_model == BLK_ZONED_HM &&
!dm_target_supports_zoned_hm(ti->type))
return false;
if (!ti->type->iterate_devices ||
!ti->type->iterate_devices(ti, device_is_zoned_model, &zoned_model))
return false;
}
return true;
}
static int device_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
unsigned int *zone_sectors = data;
return q && blk_queue_zone_sectors(q) == *zone_sectors;
}
static bool dm_table_matches_zone_sectors(struct dm_table *t,
unsigned int zone_sectors)
{
struct dm_target *ti;
unsigned i;
for (i = 0; i < dm_table_get_num_targets(t); i++) {
ti = dm_table_get_target(t, i);
if (!ti->type->iterate_devices ||
!ti->type->iterate_devices(ti, device_matches_zone_sectors, &zone_sectors))
return false;
}
return true;
}
static int validate_hardware_zoned_model(struct dm_table *table,
enum blk_zoned_model zoned_model,
unsigned int zone_sectors)
{
if (zoned_model == BLK_ZONED_NONE)
return 0;
if (!dm_table_supports_zoned_model(table, zoned_model)) {
DMERR("%s: zoned model is not consistent across all devices",
dm_device_name(table->md));
return -EINVAL;
}
/* Check zone size validity and compatibility */
if (!zone_sectors || !is_power_of_2(zone_sectors))
return -EINVAL;
if (!dm_table_matches_zone_sectors(table, zone_sectors)) {
DMERR("%s: zone sectors is not consistent across all devices",
dm_device_name(table->md));
return -EINVAL;
}
return 0;
}
/*
* Establish the new table's queue_limits and validate them.
*/
int dm_calculate_queue_limits(struct dm_table *table,
struct queue_limits *limits)
{
struct dm_target *ti;
struct queue_limits ti_limits;
unsigned i;
enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
unsigned int zone_sectors = 0;
blk_set_stacking_limits(limits);
for (i = 0; i < dm_table_get_num_targets(table); i++) {
blk_set_stacking_limits(&ti_limits);
ti = dm_table_get_target(table, i);
if (!ti->type->iterate_devices)
goto combine_limits;
/*
* Combine queue limits of all the devices this target uses.
*/
ti->type->iterate_devices(ti, dm_set_device_limits,
&ti_limits);
if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
/*
* After stacking all limits, validate all devices
* in table support this zoned model and zone sectors.
*/
zoned_model = ti_limits.zoned;
zone_sectors = ti_limits.chunk_sectors;
}
/* Set I/O hints portion of queue limits */
if (ti->type->io_hints)
ti->type->io_hints(ti, &ti_limits);
/*
* Check each device area is consistent with the target's
* overall queue limits.
*/
if (ti->type->iterate_devices(ti, device_area_is_invalid,
&ti_limits))
return -EINVAL;
combine_limits:
/*
* Merge this target's queue limits into the overall limits
* for the table.
*/
if (blk_stack_limits(limits, &ti_limits, 0) < 0)
DMWARN("%s: adding target device "
"(start sect %llu len %llu) "
"caused an alignment inconsistency",
dm_device_name(table->md),
(unsigned long long) ti->begin,
(unsigned long long) ti->len);
/*
* FIXME: this should likely be moved to blk_stack_limits(), would
* also eliminate limits->zoned stacking hack in dm_set_device_limits()
*/
if (limits->zoned == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
/*
* By default, the stacked limits zoned model is set to
* BLK_ZONED_NONE in blk_set_stacking_limits(). Update
* this model using the first target model reported
* that is not BLK_ZONED_NONE. This will be either the
* first target device zoned model or the model reported
* by the target .io_hints.
*/
limits->zoned = ti_limits.zoned;
}
}
/*
* Verify that the zoned model and zone sectors, as determined before
* any .io_hints override, are the same across all devices in the table.
* - this is especially relevant if .io_hints is emulating a disk-managed
* zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
* BUT...
*/
if (limits->zoned != BLK_ZONED_NONE) {
/*
* ...IF the above limits stacking determined a zoned model
* validate that all of the table's devices conform to it.
*/
zoned_model = limits->zoned;
zone_sectors = limits->chunk_sectors;
}
if (validate_hardware_zoned_model(table, zoned_model, zone_sectors))
return -EINVAL;
return validate_hardware_logical_block_alignment(table, limits);
}
/*
* Verify that all devices have an integrity profile that matches the
* DM device's registered integrity profile. If the profiles don't
* match then unregister the DM device's integrity profile.
*/
static void dm_table_verify_integrity(struct dm_table *t)
{
struct gendisk *template_disk = NULL;
if (t->integrity_added)
return;
if (t->integrity_supported) {
/*
* Verify that the original integrity profile
* matches all the devices in this table.
*/
template_disk = dm_table_get_integrity_disk(t);
if (template_disk &&
blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
return;
}
if (integrity_profile_exists(dm_disk(t->md))) {
DMWARN("%s: unable to establish an integrity profile",
dm_device_name(t->md));
blk_integrity_unregister(dm_disk(t->md));
}
}
static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
unsigned long flush = (unsigned long) data;
struct request_queue *q = bdev_get_queue(dev->bdev);
return q && (q->queue_flags & flush);
}
static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
{
struct dm_target *ti;
unsigned i;
/*
* Require at least one underlying device to support flushes.
* t->devices includes internal dm devices such as mirror logs
* so we need to use iterate_devices here, which targets
* supporting flushes must provide.
*/
for (i = 0; i < dm_table_get_num_targets(t); i++) {
ti = dm_table_get_target(t, i);
if (!ti->num_flush_bios)
continue;
if (ti->flush_supported)
return true;
if (ti->type->iterate_devices &&
ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
return true;
}
return false;
}
static int device_dax_write_cache_enabled(struct dm_target *ti,
struct dm_dev *dev, sector_t start,
sector_t len, void *data)
{
struct dax_device *dax_dev = dev->dax_dev;
if (!dax_dev)
return false;
if (dax_write_cache_enabled(dax_dev))
return true;
return false;
}
static int dm_table_supports_dax_write_cache(struct dm_table *t)
{
struct dm_target *ti;
unsigned i;
for (i = 0; i < dm_table_get_num_targets(t); i++) {
ti = dm_table_get_target(t, i);
if (ti->type->iterate_devices &&
ti->type->iterate_devices(ti,
device_dax_write_cache_enabled, NULL))
return true;
}
return false;
}
static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
return q && blk_queue_nonrot(q);
}
static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
return q && !blk_queue_add_random(q);
}
static bool dm_table_all_devices_attribute(struct dm_table *t,
iterate_devices_callout_fn func)
{
struct dm_target *ti;
unsigned i;
for (i = 0; i < dm_table_get_num_targets(t); i++) {
ti = dm_table_get_target(t, i);
if (!ti->type->iterate_devices ||
!ti->type->iterate_devices(ti, func, NULL))
return false;
}
return true;
}
static int device_no_partial_completion(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
char b[BDEVNAME_SIZE];
/* For now, NVMe devices are the only devices of this class */
return (strncmp(bdevname(dev->bdev, b), "nvme", 4) == 0);
}
static bool dm_table_does_not_support_partial_completion(struct dm_table *t)
{
return dm_table_all_devices_attribute(t, device_no_partial_completion);
}
static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
return q && !q->limits.max_write_same_sectors;
}
static bool dm_table_supports_write_same(struct dm_table *t)
{
struct dm_target *ti;
unsigned i;
for (i = 0; i < dm_table_get_num_targets(t); i++) {
ti = dm_table_get_target(t, i);
if (!ti->num_write_same_bios)
return false;
if (!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
return false;
}
return true;
}
static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
return q && !q->limits.max_write_zeroes_sectors;
}
static bool dm_table_supports_write_zeroes(struct dm_table *t)
{
struct dm_target *ti;
unsigned i = 0;
while (i < dm_table_get_num_targets(t)) {
ti = dm_table_get_target(t, i++);
if (!ti->num_write_zeroes_bios)
return false;
if (!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
return false;
}
return true;
}
static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
sector_t start, sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
return q && !blk_queue_discard(q);
}
static bool dm_table_supports_discards(struct dm_table *t)
{
struct dm_target *ti;
unsigned i;
for (i = 0; i < dm_table_get_num_targets(t); i++) {
ti = dm_table_get_target(t, i);
if (!ti->num_discard_bios)
return false;
/*
* Either the target provides discard support (as implied by setting
* 'discards_supported') or it relies on _all_ data devices having
* discard support.
*/
if (!ti->discards_supported &&
(!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
return false;
}
return true;
}
static int device_not_secure_erase_capable(struct dm_target *ti,
struct dm_dev *dev, sector_t start,
sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
return q && !blk_queue_secure_erase(q);
}
static bool dm_table_supports_secure_erase(struct dm_table *t)
{
struct dm_target *ti;
unsigned int i;
for (i = 0; i < dm_table_get_num_targets(t); i++) {
ti = dm_table_get_target(t, i);
if (!ti->num_secure_erase_bios)
return false;
if (!ti->type->iterate_devices ||
ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
return false;
}
return true;
}
static int device_requires_stable_pages(struct dm_target *ti,
struct dm_dev *dev, sector_t start,
sector_t len, void *data)
{
struct request_queue *q = bdev_get_queue(dev->bdev);
return q && bdi_cap_stable_pages_required(q->backing_dev_info);
}
/*
* If any underlying device requires stable pages, a table must require
* them as well. Only targets that support iterate_devices are considered:
* don't want error, zero, etc to require stable pages.
*/
static bool dm_table_requires_stable_pages(struct dm_table *t)
{
struct dm_target *ti;
unsigned i;
for (i = 0; i < dm_table_get_num_targets(t); i++) {
ti = dm_table_get_target(t, i);
if (ti->type->iterate_devices &&
ti->type->iterate_devices(ti, device_requires_stable_pages, NULL))
return true;
}
return false;
}
void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
struct queue_limits *limits)
{
bool wc = false, fua = false;
int page_size = PAGE_SIZE;
/*
* Copy table's limits to the DM device's request_queue
*/
q->limits = *limits;
if (!dm_table_supports_discards(t)) {
blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q);
/* Must also clear discard limits... */
q->limits.max_discard_sectors = 0;
q->limits.max_hw_discard_sectors = 0;
q->limits.discard_granularity = 0;
q->limits.discard_alignment = 0;
q->limits.discard_misaligned = 0;
} else
blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
if (dm_table_supports_secure_erase(t))
blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
wc = true;
if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
fua = true;
}
blk_queue_write_cache(q, wc, fua);
if (dm_table_supports_dax(t, device_supports_dax, &page_size)) {
blk_queue_flag_set(QUEUE_FLAG_DAX, q);
if (dm_table_supports_dax(t, device_dax_synchronous, NULL))
set_dax_synchronous(t->md->dax_dev);
}
else
blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
if (dm_table_supports_dax_write_cache(t))
dax_write_cache(t->md->dax_dev, true);
/* Ensure that all underlying devices are non-rotational. */
if (dm_table_all_devices_attribute(t, device_is_nonrot))
blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
else
blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
if (!dm_table_supports_write_same(t))
q->limits.max_write_same_sectors = 0;
if (!dm_table_supports_write_zeroes(t))
q->limits.max_write_zeroes_sectors = 0;
dm_table_verify_integrity(t);
/*
* Some devices don't use blk_integrity but still want stable pages
* because they do their own checksumming.
*/
if (dm_table_requires_stable_pages(t))
q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
else
q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
/*
* Determine whether or not this queue's I/O timings contribute
* to the entropy pool, Only request-based targets use this.
* Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
* have it set.
*/
if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
/*
* For a zoned target, the number of zones should be updated for the
* correct value to be exposed in sysfs queue/nr_zones. For a BIO based
* target, this is all that is needed. For a request based target, the
* queue zone bitmaps must also be updated.
* Use blk_revalidate_disk_zones() to handle this.
*/
if (blk_queue_is_zoned(q))
blk_revalidate_disk_zones(t->md->disk);
/* Allow reads to exceed readahead limits */
q->backing_dev_info->io_pages = limits->max_sectors >> (PAGE_SHIFT - 9);
}
unsigned int dm_table_get_num_targets(struct dm_table *t)
{
return t->num_targets;
}
struct list_head *dm_table_get_devices(struct dm_table *t)
{
return &t->devices;
}
fmode_t dm_table_get_mode(struct dm_table *t)
{
return t->mode;
}
EXPORT_SYMBOL(dm_table_get_mode);
enum suspend_mode {
PRESUSPEND,
PRESUSPEND_UNDO,
POSTSUSPEND,
};
static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
{
int i = t->num_targets;
struct dm_target *ti = t->targets;
lockdep_assert_held(&t->md->suspend_lock);
while (i--) {
switch (mode) {
case PRESUSPEND:
if (ti->type->presuspend)
ti->type->presuspend(ti);
break;
case PRESUSPEND_UNDO:
if (ti->type->presuspend_undo)
ti->type->presuspend_undo(ti);
break;
case POSTSUSPEND:
if (ti->type->postsuspend)
ti->type->postsuspend(ti);
break;
}
ti++;
}
}
void dm_table_presuspend_targets(struct dm_table *t)
{
if (!t)
return;
suspend_targets(t, PRESUSPEND);
}
void dm_table_presuspend_undo_targets(struct dm_table *t)
{
if (!t)
return;
suspend_targets(t, PRESUSPEND_UNDO);
}
void dm_table_postsuspend_targets(struct dm_table *t)
{
if (!t)
return;
suspend_targets(t, POSTSUSPEND);
}
int dm_table_resume_targets(struct dm_table *t)
{
int i, r = 0;
lockdep_assert_held(&t->md->suspend_lock);
for (i = 0; i < t->num_targets; i++) {
struct dm_target *ti = t->targets + i;
if (!ti->type->preresume)
continue;
r = ti->type->preresume(ti);
if (r) {
DMERR("%s: %s: preresume failed, error = %d",
dm_device_name(t->md), ti->type->name, r);
return r;
}
}
for (i = 0; i < t->num_targets; i++) {
struct dm_target *ti = t->targets + i;
if (ti->type->resume)
ti->type->resume(ti);
}
return 0;
}
void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
{
list_add(&cb->list, &t->target_callbacks);
}
EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
int dm_table_any_congested(struct dm_table *t, int bdi_bits)
{
struct dm_dev_internal *dd;
struct list_head *devices = dm_table_get_devices(t);
struct dm_target_callbacks *cb;
int r = 0;
list_for_each_entry(dd, devices, list) {
struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);
char b[BDEVNAME_SIZE];
if (likely(q))
r |= bdi_congested(q->backing_dev_info, bdi_bits);
else
DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
dm_device_name(t->md),
bdevname(dd->dm_dev->bdev, b));
}
list_for_each_entry(cb, &t->target_callbacks, list)
if (cb->congested_fn)
r |= cb->congested_fn(cb, bdi_bits);
return r;
}
struct mapped_device *dm_table_get_md(struct dm_table *t)
{
return t->md;
}
EXPORT_SYMBOL(dm_table_get_md);
const char *dm_table_device_name(struct dm_table *t)
{
return dm_device_name(t->md);
}
EXPORT_SYMBOL_GPL(dm_table_device_name);
void dm_table_run_md_queue_async(struct dm_table *t)
{
struct mapped_device *md;
struct request_queue *queue;
if (!dm_table_request_based(t))
return;
md = dm_table_get_md(t);
queue = dm_get_md_queue(md);
if (queue)
blk_mq_run_hw_queues(queue, true);
}
EXPORT_SYMBOL(dm_table_run_md_queue_async);