| /* |
| * 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.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 <asm/atomic.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) |
| |
| /* |
| * The table has always exactly one reference from either mapped_device->map |
| * or hash_cell->new_map. This reference is not counted in table->holders. |
| * A pair of dm_create_table/dm_destroy_table functions is used for table |
| * creation/destruction. |
| * |
| * Temporary references from the other code increase table->holders. A pair |
| * of dm_table_get/dm_table_put functions is used to manipulate it. |
| * |
| * When the table is about to be destroyed, we wait for table->holders to |
| * drop to zero. |
| */ |
| |
| struct dm_table { |
| struct mapped_device *md; |
| atomic_t holders; |
| unsigned 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; |
| |
| /* |
| * 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; |
| }; |
| |
| /* |
| * 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 = vmalloc(size); |
| if (addr) |
| memset(addr, 0, size); |
| |
| return addr; |
| } |
| |
| /* |
| * 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; |
| int n = t->num_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); |
| |
| if (n) { |
| memcpy(n_highs, t->highs, sizeof(*n_highs) * n); |
| memcpy(n_targets, t->targets, sizeof(*n_targets) * n); |
| } |
| |
| memset(n_highs + n, -1, sizeof(*n_highs) * (num - n)); |
| 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); |
| atomic_set(&t->holders, 0); |
| |
| if (!num_targets) |
| num_targets = KEYS_PER_NODE; |
| |
| num_targets = dm_round_up(num_targets, KEYS_PER_NODE); |
| |
| if (alloc_targets(t, num_targets)) { |
| kfree(t); |
| t = NULL; |
| return -ENOMEM; |
| } |
| |
| t->mode = mode; |
| t->md = md; |
| *result = t; |
| return 0; |
| } |
| |
| static void free_devices(struct list_head *devices) |
| { |
| 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("dm_table_destroy: dm_put_device call missing for %s", |
| dd->dm_dev.name); |
| kfree(dd); |
| } |
| } |
| |
| void dm_table_destroy(struct dm_table *t) |
| { |
| unsigned int i; |
| |
| if (!t) |
| return; |
| |
| while (atomic_read(&t->holders)) |
| msleep(1); |
| smp_mb(); |
| |
| /* 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 */ |
| if (t->devices.next != &t->devices) |
| free_devices(&t->devices); |
| |
| dm_free_md_mempools(t->mempools); |
| |
| kfree(t); |
| } |
| |
| void dm_table_get(struct dm_table *t) |
| { |
| atomic_inc(&t->holders); |
| } |
| |
| void dm_table_put(struct dm_table *t) |
| { |
| if (!t) |
| return; |
| |
| smp_mb__before_atomic_dec(); |
| atomic_dec(&t->holders); |
| } |
| |
| /* |
| * Checks to see if we need to extend highs or targets. |
| */ |
| static inline int check_space(struct dm_table *t) |
| { |
| if (t->num_targets >= t->num_allocated) |
| return alloc_targets(t, t->num_allocated * 2); |
| |
| return 0; |
| } |
| |
| /* |
| * 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; |
| } |
| |
| /* |
| * Open a device so we can use it as a map destination. |
| */ |
| static int open_dev(struct dm_dev_internal *d, dev_t dev, |
| struct mapped_device *md) |
| { |
| static char *_claim_ptr = "I belong to device-mapper"; |
| struct block_device *bdev; |
| |
| int r; |
| |
| BUG_ON(d->dm_dev.bdev); |
| |
| bdev = open_by_devnum(dev, d->dm_dev.mode); |
| if (IS_ERR(bdev)) |
| return PTR_ERR(bdev); |
| r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md)); |
| if (r) |
| blkdev_put(bdev, d->dm_dev.mode); |
| else |
| d->dm_dev.bdev = bdev; |
| return r; |
| } |
| |
| /* |
| * Close a device that we've been using. |
| */ |
| static void close_dev(struct dm_dev_internal *d, struct mapped_device *md) |
| { |
| if (!d->dm_dev.bdev) |
| return; |
| |
| bd_release_from_disk(d->dm_dev.bdev, dm_disk(md)); |
| blkdev_put(d->dm_dev.bdev, d->dm_dev.mode); |
| d->dm_dev.bdev = 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 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]; |
| |
| 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 (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_internal dd_new, dd_old; |
| |
| dd_new = dd_old = *dd; |
| |
| dd_new.dm_dev.mode |= new_mode; |
| dd_new.dm_dev.bdev = NULL; |
| |
| r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md); |
| if (r) |
| return r; |
| |
| dd->dm_dev.mode |= new_mode; |
| close_dev(&dd_old, md); |
| |
| return 0; |
| } |
| |
| /* |
| * Add a device to the list, or just increment the usage count if |
| * it's already present. |
| */ |
| static int __table_get_device(struct dm_table *t, struct dm_target *ti, |
| const char *path, fmode_t mode, struct dm_dev **result) |
| { |
| int r; |
| dev_t uninitialized_var(dev); |
| struct dm_dev_internal *dd; |
| unsigned int major, minor; |
| |
| BUG_ON(!t); |
| |
| if (sscanf(path, "%u:%u", &major, &minor) == 2) { |
| /* Extract the major/minor numbers */ |
| dev = MKDEV(major, minor); |
| if (MAJOR(dev) != major || MINOR(dev) != minor) |
| return -EOVERFLOW; |
| } else { |
| /* convert the path to a device */ |
| struct block_device *bdev = lookup_bdev(path); |
| |
| if (IS_ERR(bdev)) |
| return PTR_ERR(bdev); |
| dev = bdev->bd_dev; |
| bdput(bdev); |
| } |
| |
| dd = find_device(&t->devices, dev); |
| if (!dd) { |
| dd = kmalloc(sizeof(*dd), GFP_KERNEL); |
| if (!dd) |
| return -ENOMEM; |
| |
| dd->dm_dev.mode = mode; |
| dd->dm_dev.bdev = NULL; |
| |
| if ((r = open_dev(dd, dev, t->md))) { |
| kfree(dd); |
| return r; |
| } |
| |
| format_dev_t(dd->dm_dev.name, dev); |
| |
| atomic_set(&dd->count, 0); |
| list_add(&dd->list, &t->devices); |
| |
| } else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) { |
| r = upgrade_mode(dd, mode, t->md); |
| if (r) |
| return r; |
| } |
| atomic_inc(&dd->count); |
| |
| *result = &dd->dm_dev; |
| return 0; |
| } |
| |
| /* |
| * Returns the minimum that is _not_ zero, unless both are zero. |
| */ |
| #define min_not_zero(l, r) (l == 0) ? r : ((r == 0) ? l : min(l, r)) |
| |
| 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); |
| |
| /* |
| * Check if merge fn is supported. |
| * If not we'll force DM to use PAGE_SIZE or |
| * smaller I/O, just to be safe. |
| */ |
| |
| if (q->merge_bvec_fn && !ti->type->merge) |
| limits->max_sectors = |
| min_not_zero(limits->max_sectors, |
| (unsigned int) (PAGE_SIZE >> 9)); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(dm_set_device_limits); |
| |
| int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode, |
| struct dm_dev **result) |
| { |
| return __table_get_device(ti->table, ti, path, mode, result); |
| } |
| |
| |
| /* |
| * Decrement a devices use count and remove it if necessary. |
| */ |
| void dm_put_device(struct dm_target *ti, struct dm_dev *d) |
| { |
| struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal, |
| dm_dev); |
| |
| if (atomic_dec_and_test(&dd->count)) { |
| close_dev(dd, ti->table->md); |
| list_del(&dd->list); |
| kfree(dd); |
| } |
| } |
| |
| /* |
| * 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. |
| */ |
| static char **realloc_argv(unsigned *array_size, char **old_argv) |
| { |
| char **argv; |
| unsigned new_size; |
| |
| new_size = *array_size ? *array_size * 2 : 64; |
| argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL); |
| if (argv) { |
| memcpy(argv, old_argv, *array_size * sizeof(*argv)); |
| *array_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 = 0; |
| |
| /* |
| * Check each entry in the table in turn. |
| */ |
| while (i < dm_table_get_num_targets(table)) { |
| ti = dm_table_get_target(table, i++); |
| |
| blk_set_default_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 ((r = check_space(t))) |
| return r; |
| |
| 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; |
| } |
| |
| 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"; |
| r = -EINVAL; |
| 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; |
| |
| return 0; |
| |
| bad: |
| DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error); |
| dm_put_target_type(tgt->type); |
| return r; |
| } |
| |
| static int dm_table_set_type(struct dm_table *t) |
| { |
| unsigned i; |
| unsigned bio_based = 0, request_based = 0; |
| struct dm_target *tgt; |
| struct dm_dev_internal *dd; |
| struct list_head *devices; |
| |
| for (i = 0; i < t->num_targets; i++) { |
| tgt = t->targets + i; |
| if (dm_target_request_based(tgt)) |
| request_based = 1; |
| else |
| bio_based = 1; |
| |
| if (bio_based && request_based) { |
| DMWARN("Inconsistent table: different target types" |
| " can't be mixed up"); |
| return -EINVAL; |
| } |
| } |
| |
| if (bio_based) { |
| /* We must use this table as bio-based */ |
| t->type = DM_TYPE_BIO_BASED; |
| return 0; |
| } |
| |
| BUG_ON(!request_based); /* No targets in this table */ |
| |
| /* Non-request-stackable devices can't be used for request-based dm */ |
| devices = dm_table_get_devices(t); |
| list_for_each_entry(dd, devices, list) { |
| if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) { |
| DMWARN("table load rejected: including" |
| " non-request-stackable devices"); |
| return -EINVAL; |
| } |
| } |
| |
| /* |
| * 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) { |
| DMWARN("Request-based dm doesn't support multiple targets yet"); |
| return -EINVAL; |
| } |
| |
| t->type = DM_TYPE_REQUEST_BASED; |
| |
| return 0; |
| } |
| |
| unsigned dm_table_get_type(struct dm_table *t) |
| { |
| return t->type; |
| } |
| |
| bool dm_table_request_based(struct dm_table *t) |
| { |
| return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED; |
| } |
| |
| int dm_table_alloc_md_mempools(struct dm_table *t) |
| { |
| unsigned type = dm_table_get_type(t); |
| |
| if (unlikely(type == DM_TYPE_NONE)) { |
| DMWARN("no table type is set, can't allocate mempools"); |
| return -EINVAL; |
| } |
| |
| t->mempools = dm_alloc_md_mempools(type); |
| 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; |
| } |
| |
| /* |
| * Register the mapped device for blk_integrity support if |
| * the underlying devices support it. |
| */ |
| static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md) |
| { |
| struct list_head *devices = dm_table_get_devices(t); |
| struct dm_dev_internal *dd; |
| |
| list_for_each_entry(dd, devices, list) |
| if (bdev_get_integrity(dd->dm_dev.bdev)) |
| return blk_integrity_register(dm_disk(md), NULL); |
| |
| 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_set_type(t); |
| if (r) { |
| DMERR("unable to set table type"); |
| return r; |
| } |
| |
| r = dm_table_build_index(t); |
| if (r) { |
| DMERR("unable to build btrees"); |
| return r; |
| } |
| |
| r = dm_table_prealloc_integrity(t, t->md); |
| if (r) { |
| DMERR("could not register integrity profile."); |
| return r; |
| } |
| |
| r = dm_table_alloc_md_mempools(t); |
| 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); |
| } |
| |
| sector_t dm_table_get_size(struct dm_table *t) |
| { |
| return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; |
| } |
| |
| 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; |
| |
| 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]; |
| } |
| |
| /* |
| * 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 *uninitialized_var(ti); |
| struct queue_limits ti_limits; |
| unsigned i = 0; |
| |
| blk_set_default_limits(limits); |
| |
| while (i < dm_table_get_num_targets(table)) { |
| blk_set_default_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); |
| |
| /* 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); |
| } |
| |
| return validate_hardware_logical_block_alignment(table, limits); |
| } |
| |
| /* |
| * Set the integrity profile for this device if all devices used have |
| * matching profiles. |
| */ |
| static void dm_table_set_integrity(struct dm_table *t) |
| { |
| struct list_head *devices = dm_table_get_devices(t); |
| struct dm_dev_internal *prev = NULL, *dd = NULL; |
| |
| if (!blk_get_integrity(dm_disk(t->md))) |
| return; |
| |
| list_for_each_entry(dd, devices, list) { |
| if (prev && |
| blk_integrity_compare(prev->dm_dev.bdev->bd_disk, |
| dd->dm_dev.bdev->bd_disk) < 0) { |
| DMWARN("%s: integrity not set: %s and %s mismatch", |
| dm_device_name(t->md), |
| prev->dm_dev.bdev->bd_disk->disk_name, |
| dd->dm_dev.bdev->bd_disk->disk_name); |
| goto no_integrity; |
| } |
| prev = dd; |
| } |
| |
| if (!prev || !bdev_get_integrity(prev->dm_dev.bdev)) |
| goto no_integrity; |
| |
| blk_integrity_register(dm_disk(t->md), |
| bdev_get_integrity(prev->dm_dev.bdev)); |
| |
| return; |
| |
| no_integrity: |
| blk_integrity_register(dm_disk(t->md), NULL); |
| |
| return; |
| } |
| |
| void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q, |
| struct queue_limits *limits) |
| { |
| /* |
| * Copy table's limits to the DM device's request_queue |
| */ |
| q->limits = *limits; |
| |
| if (limits->no_cluster) |
| queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q); |
| else |
| queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q); |
| |
| dm_table_set_integrity(t); |
| |
| /* |
| * QUEUE_FLAG_STACKABLE must be set after all queue settings are |
| * visible to other CPUs because, once the flag is set, incoming bios |
| * are processed by request-based dm, which refers to the queue |
| * settings. |
| * Until the flag set, bios are passed to bio-based dm and queued to |
| * md->deferred where queue settings are not needed yet. |
| * Those bios are passed to request-based dm at the resume time. |
| */ |
| smp_mb(); |
| if (dm_table_request_based(t)) |
| queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, 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; |
| } |
| |
| static void suspend_targets(struct dm_table *t, unsigned postsuspend) |
| { |
| int i = t->num_targets; |
| struct dm_target *ti = t->targets; |
| |
| while (i--) { |
| if (postsuspend) { |
| if (ti->type->postsuspend) |
| ti->type->postsuspend(ti); |
| } else if (ti->type->presuspend) |
| ti->type->presuspend(ti); |
| |
| ti++; |
| } |
| } |
| |
| void dm_table_presuspend_targets(struct dm_table *t) |
| { |
| if (!t) |
| return; |
| |
| suspend_targets(t, 0); |
| } |
| |
| void dm_table_postsuspend_targets(struct dm_table *t) |
| { |
| if (!t) |
| return; |
| |
| suspend_targets(t, 1); |
| } |
| |
| int dm_table_resume_targets(struct dm_table *t) |
| { |
| int i, r = 0; |
| |
| 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) |
| 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; |
| } |
| |
| 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); |
| 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)); |
| } |
| |
| return r; |
| } |
| |
| int dm_table_any_busy_target(struct dm_table *t) |
| { |
| unsigned i; |
| struct dm_target *ti; |
| |
| for (i = 0; i < t->num_targets; i++) { |
| ti = t->targets + i; |
| if (ti->type->busy && ti->type->busy(ti)) |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| void dm_table_unplug_all(struct dm_table *t) |
| { |
| struct dm_dev_internal *dd; |
| struct list_head *devices = dm_table_get_devices(t); |
| |
| 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)) |
| blk_unplug(q); |
| else |
| DMWARN_LIMIT("%s: Cannot unplug nonexistent device %s", |
| dm_device_name(t->md), |
| bdevname(dd->dm_dev.bdev, b)); |
| } |
| } |
| |
| struct mapped_device *dm_table_get_md(struct dm_table *t) |
| { |
| return t->md; |
| } |
| |
| EXPORT_SYMBOL(dm_vcalloc); |
| EXPORT_SYMBOL(dm_get_device); |
| EXPORT_SYMBOL(dm_put_device); |
| EXPORT_SYMBOL(dm_table_event); |
| EXPORT_SYMBOL(dm_table_get_size); |
| EXPORT_SYMBOL(dm_table_get_mode); |
| EXPORT_SYMBOL(dm_table_get_md); |
| EXPORT_SYMBOL(dm_table_put); |
| EXPORT_SYMBOL(dm_table_get); |
| EXPORT_SYMBOL(dm_table_unplug_all); |