struct dm_table {
struct mapped_device *md;
atomic_t holders;
+ unsigned type;
/* btree table */
unsigned int depth;
/* a list of devices used by this table */
struct list_head devices;
- /*
- * These are optimistic limits taken from all the
- * targets, some targets will need smaller limits.
- */
- struct io_restrictions limits;
-
/* events get handed up using this callback */
void (*event_fn)(void *);
void *event_context;
+
+ struct dm_md_mempools *mempools;
};
/*
return result;
}
-/*
- * 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))
-
-/*
- * Combine two io_restrictions, always taking the lower value.
- */
-static void combine_restrictions_low(struct io_restrictions *lhs,
- struct io_restrictions *rhs)
-{
- lhs->max_sectors =
- min_not_zero(lhs->max_sectors, rhs->max_sectors);
-
- lhs->max_phys_segments =
- min_not_zero(lhs->max_phys_segments, rhs->max_phys_segments);
-
- lhs->max_hw_segments =
- min_not_zero(lhs->max_hw_segments, rhs->max_hw_segments);
-
- lhs->logical_block_size = max(lhs->logical_block_size,
- rhs->logical_block_size);
-
- lhs->max_segment_size =
- min_not_zero(lhs->max_segment_size, rhs->max_segment_size);
-
- lhs->max_hw_sectors =
- min_not_zero(lhs->max_hw_sectors, rhs->max_hw_sectors);
-
- lhs->seg_boundary_mask =
- min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask);
-
- lhs->bounce_pfn = min_not_zero(lhs->bounce_pfn, rhs->bounce_pfn);
-
- lhs->no_cluster |= rhs->no_cluster;
-}
-
/*
* Calculate the index of the child node of the n'th node k'th key.
*/
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);
}
}
vfree(t->highs);
/* free the device list */
- if (t->devices.next != &t->devices) {
- DMWARN("devices still present during destroy: "
- "dm_table_remove_device calls missing");
-
+ if (t->devices.next != &t->devices)
free_devices(&t->devices);
- }
+
+ dm_free_md_mempools(t->mempools);
kfree(t);
}
/*
* If possible, this checks an area of a destination device is valid.
*/
-static int check_device_area(struct dm_dev_internal *dd, sector_t start,
- sector_t len)
+static int device_area_is_valid(struct dm_target *ti, struct dm_dev *dev,
+ sector_t start, sector_t len, void *data)
{
- sector_t dev_size = dd->dm_dev.bdev->bd_inode->i_size >> SECTOR_SHIFT;
+ 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 1;
- return ((start < dev_size) && (len <= (dev_size - start)));
+ if ((start >= dev_size) || (start + len > dev_size)) {
+ DMWARN("%s: %s too small for target",
+ dm_device_name(ti->table->md), bdevname(bdev, b));
+ return 0;
+ }
+
+ if (logical_block_size_sectors <= 1)
+ return 1;
+
+ if (start & (logical_block_size_sectors - 1)) {
+ DMWARN("%s: start=%llu not aligned to h/w "
+ "logical block size %hu of %s",
+ dm_device_name(ti->table->md),
+ (unsigned long long)start,
+ limits->logical_block_size, bdevname(bdev, b));
+ return 0;
+ }
+
+ if (len & (logical_block_size_sectors - 1)) {
+ DMWARN("%s: len=%llu not aligned to h/w "
+ "logical block size %hu of %s",
+ dm_device_name(ti->table->md),
+ (unsigned long long)len,
+ limits->logical_block_size, bdevname(bdev, b));
+ return 0;
+ }
+
+ return 1;
}
/*
}
atomic_inc(&dd->count);
- if (!check_device_area(dd, start, len)) {
- DMWARN("device %s too small for target", path);
- dm_put_device(ti, &dd->dm_dev);
- return -EINVAL;
- }
-
*result = &dd->dm_dev;
-
return 0;
}
-void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev)
+/*
+ * 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);
- struct io_restrictions *rs = &ti->limits;
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;
+ return 0;
}
- /*
- * Combine the device limits low.
- *
- * FIXME: if we move an io_restriction struct
- * into q this would just be a call to
- * combine_restrictions_low()
- */
- rs->max_sectors =
- min_not_zero(rs->max_sectors, q->max_sectors);
+ if (blk_stack_limits(limits, &q->limits, start << 9) < 0)
+ DMWARN("%s: target device %s is misaligned",
+ dm_device_name(ti->table->md), bdevname(bdev, b));
/*
* Check if merge fn is supported.
*/
if (q->merge_bvec_fn && !ti->type->merge)
- rs->max_sectors =
- min_not_zero(rs->max_sectors,
+ limits->max_sectors =
+ min_not_zero(limits->max_sectors,
(unsigned int) (PAGE_SIZE >> 9));
-
- rs->max_phys_segments =
- min_not_zero(rs->max_phys_segments,
- q->max_phys_segments);
-
- rs->max_hw_segments =
- min_not_zero(rs->max_hw_segments, q->max_hw_segments);
-
- rs->logical_block_size = max(rs->logical_block_size,
- queue_logical_block_size(q));
-
- rs->max_segment_size =
- min_not_zero(rs->max_segment_size, q->max_segment_size);
-
- rs->max_hw_sectors =
- min_not_zero(rs->max_hw_sectors, q->max_hw_sectors);
-
- rs->seg_boundary_mask =
- min_not_zero(rs->seg_boundary_mask,
- q->seg_boundary_mask);
-
- rs->bounce_pfn = min_not_zero(rs->bounce_pfn, q->bounce_pfn);
-
- rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
+ return 0;
}
EXPORT_SYMBOL_GPL(dm_set_device_limits);
int dm_get_device(struct dm_target *ti, const char *path, sector_t start,
sector_t len, fmode_t mode, struct dm_dev **result)
{
- int r = __table_get_device(ti->table, ti, path,
- start, len, mode, result);
-
- if (!r)
- dm_set_device_limits(ti, (*result)->bdev);
-
- return r;
+ return __table_get_device(ti->table, ti, path,
+ start, len, mode, result);
}
+
/*
* Decrement a devices use count and remove it if necessary.
*/
return 0;
}
-static void check_for_valid_limits(struct io_restrictions *rs)
+/*
+ * 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)
{
- if (!rs->max_sectors)
- rs->max_sectors = SAFE_MAX_SECTORS;
- if (!rs->max_hw_sectors)
- rs->max_hw_sectors = SAFE_MAX_SECTORS;
- if (!rs->max_phys_segments)
- rs->max_phys_segments = MAX_PHYS_SEGMENTS;
- if (!rs->max_hw_segments)
- rs->max_hw_segments = MAX_HW_SEGMENTS;
- if (!rs->logical_block_size)
- rs->logical_block_size = 1 << SECTOR_SHIFT;
- if (!rs->max_segment_size)
- rs->max_segment_size = MAX_SEGMENT_SIZE;
- if (!rs->seg_boundary_mask)
- rs->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
- if (!rs->bounce_pfn)
- rs->bounce_pfn = -1;
+ /*
+ * 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 %hu",
+ 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,
t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
- /* FIXME: the plan is to combine high here and then have
- * the merge fn apply the target level restrictions. */
- combine_restrictions_low(&t->limits, &tgt->limits);
return 0;
bad:
return r;
}
+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;
int r = 0;
unsigned int leaf_nodes;
- check_for_valid_limits(&t->limits);
-
/* 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);
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);
+
+ /*
+ * Check each device area is consistent with the target's
+ * overall queue limits.
+ */
+ if (!ti->type->iterate_devices(ti, device_area_is_valid,
+ &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: target device "
+ "(start sect %llu len %llu) "
+ "is misaligned",
+ 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.
return;
}
-void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q)
+void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
+ struct queue_limits *limits)
{
/*
- * Make sure we obey the optimistic sub devices
- * restrictions.
+ * Each target device in the table has a data area that should normally
+ * be aligned such that the DM device's alignment_offset is 0.
+ * FIXME: Propagate alignment_offsets up the stack and warn of
+ * sub-optimal or inconsistent settings.
+ */
+ limits->alignment_offset = 0;
+ limits->misaligned = 0;
+
+ /*
+ * Copy table's limits to the DM device's request_queue
*/
- blk_queue_max_sectors(q, t->limits.max_sectors);
- q->max_phys_segments = t->limits.max_phys_segments;
- q->max_hw_segments = t->limits.max_hw_segments;
- q->logical_block_size = t->limits.logical_block_size;
- q->max_segment_size = t->limits.max_segment_size;
- q->max_hw_sectors = t->limits.max_hw_sectors;
- q->seg_boundary_mask = t->limits.seg_boundary_mask;
- q->bounce_pfn = t->limits.bounce_pfn;
-
- if (t->limits.no_cluster)
+ 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 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;
git.openpandora.org / pandora-kernel.git / blobdiff