diff options
Diffstat (limited to 'drivers/md/dm-table.c')
| -rw-r--r-- | drivers/md/dm-table.c | 2121 |
1 files changed, 2121 insertions, 0 deletions
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c new file mode 100644 index 000000000..71d3fdbce --- /dev/null +++ b/drivers/md/dm-table.c @@ -0,0 +1,2121 @@ +/* + * 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; + bool all_blk_mq: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. + * Append an empty entry to catch sectors beyond the end of + * the device. + */ + n_highs = (sector_t *) dm_vcalloc(num + 1, 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; + unsigned int major, minor; + char dummy; + struct dm_dev_internal *dd; + struct dm_table *t = ti->table; + + BUG_ON(!t); + + if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) { + /* Extract the major/minor numbers */ + dev = MKDEV(major, minor); + if (MAJOR(dev) != major || MINOR(dev) != minor) + return -EOVERFLOW; + } else { + 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 || + table_type == DM_TYPE_MQ_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); + +static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev, + sector_t start, sector_t len, void *data) +{ + return !bdev_dax_supported(dev->bdev, PAGE_SIZE); +} + +static bool dm_table_supports_dax(struct dm_table *t) +{ + 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, device_not_dax_capable, NULL)) + 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 (q->mq_ops) + v->mq_count++; + else + v->sq_count++; + + return queue_is_rq_based(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); + + 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) || + (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 */ + + /* + * The only way to establish DM_TYPE_MQ_REQUEST_BASED is by + * having a compatible target use dm_table_set_type. + */ + 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 and all_blk_mq */ + if (live_table) { + t->type = live_table->type; + t->all_blk_mq = live_table->all_blk_mq; + } + 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 && v.mq_count) { + DMERR("table load rejected: not all devices are blk-mq request-stackable"); + return -EINVAL; + } + t->all_blk_mq = v.mq_count > 0; + + if (!t->all_blk_mq && + (t->type == DM_TYPE_MQ_REQUEST_BASED || t->type == DM_TYPE_NVME_BIO_BASED)) { + DMERR("table load rejected: all devices are not 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)); +} + +bool dm_table_all_blk_mq_devices(struct dm_table *t) +{ + return t->all_blk_mq; +} + +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) +{ + 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 with dm_target_is_valid() + * 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 &t->targets[t->num_targets]; + + 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]; +} + +/* + * type->iterate_devices() should be called when the sanity check needs to + * iterate and check all underlying data devices. iterate_devices() will + * iterate all underlying data devices until it encounters a non-zero return + * code, returned by whether the input iterate_devices_callout_fn, or + * iterate_devices() itself internally. + * + * For some target type (e.g. dm-stripe), one call of iterate_devices() may + * iterate multiple underlying devices internally, in which case a non-zero + * return code returned by iterate_devices_callout_fn will stop the iteration + * in advance. + * + * Cases requiring _any_ underlying device supporting some kind of attribute, + * should use the iteration structure like dm_table_any_dev_attr(), or call + * it directly. @func should handle semantics of positive examples, e.g. + * capable of something. + * + * Cases requiring _all_ underlying devices supporting some kind of attribute, + * should use the iteration structure like dm_table_supports_nowait() or + * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that + * uses an @anti_func that handle semantics of counter examples, e.g. not + * capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data); + */ +static bool dm_table_any_dev_attr(struct dm_table *t, + iterate_devices_callout_fn func, void *data) +{ + 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->type->iterate_devices && + ti->type->iterate_devices(ti, func, data)) + return true; + } + + return false; +} + +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_not_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_not_zoned_model, &zoned_model)) + return false; + } + + return true; +} + +static int device_not_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 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_any_dev_attr(table, device_not_matches_zone_sectors, &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 device_is_rotational(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 int queue_no_sg_merge(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 && test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags); +} + +static int device_is_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_any_dev_attr(t, device_is_partial_completion, NULL); +} + +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); +} + +void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, + struct queue_limits *limits) +{ + bool wc = false, fua = false; + + /* + * 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)) + blk_queue_flag_set(QUEUE_FLAG_DAX, q); + else + blk_queue_flag_clear(QUEUE_FLAG_DAX, q); + + if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL)) + dax_write_cache(t->md->dax_dev, true); + + /* Ensure that all underlying devices are non-rotational. */ + if (dm_table_any_dev_attr(t, device_is_rotational, NULL)) + blk_queue_flag_clear(QUEUE_FLAG_NONROT, q); + else + blk_queue_flag_set(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; + + if (dm_table_any_dev_attr(t, queue_no_sg_merge, NULL)) + blk_queue_flag_set(QUEUE_FLAG_NO_SG_MERGE, q); + else + blk_queue_flag_clear(QUEUE_FLAG_NO_SG_MERGE, q); + + dm_table_verify_integrity(t); + + /* + * Some devices don't use blk_integrity but still want stable pages + * because they do their own checksumming. + * 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. + */ + if (dm_table_any_dev_attr(t, device_requires_stable_pages, NULL)) + 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_any_dev_attr(t, device_is_not_random, NULL)) + blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q); +} + +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); + +void dm_table_run_md_queue_async(struct dm_table *t) +{ + struct mapped_device *md; + struct request_queue *queue; + unsigned long flags; + + if (!dm_table_request_based(t)) + return; + + md = dm_table_get_md(t); + queue = dm_get_md_queue(md); + if (queue) { + if (queue->mq_ops) + blk_mq_run_hw_queues(queue, true); + else { + spin_lock_irqsave(queue->queue_lock, flags); + blk_run_queue_async(queue); + spin_unlock_irqrestore(queue->queue_lock, flags); + } + } +} +EXPORT_SYMBOL(dm_table_run_md_queue_async); + |