}
EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);
-/**
- * blk_set_default_limits - reset limits to default values
- * @lim: the queue_limits structure to reset
- *
- * Description:
- * Returns a queue_limit struct to its default state.
- */
-void blk_set_default_limits(struct queue_limits *lim)
-{
- lim->max_segments = BLK_MAX_SEGMENTS;
- lim->max_discard_segments = 1;
- lim->max_integrity_segments = 0;
- lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
- lim->virt_boundary_mask = 0;
- lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
- lim->max_sectors = lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
- lim->max_user_sectors = lim->max_dev_sectors = 0;
- lim->chunk_sectors = 0;
- lim->max_write_zeroes_sectors = 0;
- lim->max_zone_append_sectors = 0;
- lim->max_discard_sectors = 0;
- lim->max_hw_discard_sectors = 0;
- lim->max_secure_erase_sectors = 0;
- lim->discard_granularity = 512;
- lim->discard_alignment = 0;
- lim->discard_misaligned = 0;
- lim->logical_block_size = lim->physical_block_size = lim->io_min = 512;
- lim->bounce = BLK_BOUNCE_NONE;
- lim->alignment_offset = 0;
- lim->io_opt = 0;
- lim->misaligned = 0;
- lim->zoned = false;
- lim->zone_write_granularity = 0;
- lim->dma_alignment = 511;
-}
-
/**
* blk_set_stacking_limits - set default limits for stacking devices
* @lim: the queue_limits structure to reset
*
- * Description:
- * Returns a queue_limit struct to its default state. Should be used
- * by stacking drivers like DM that have no internal limits.
+ * Prepare queue limits for applying limits from underlying devices using
+ * blk_stack_limits().
*/
void blk_set_stacking_limits(struct queue_limits *lim)
{
- blk_set_default_limits(lim);
+ memset(lim, 0, sizeof(*lim));
+ lim->logical_block_size = SECTOR_SIZE;
+ lim->physical_block_size = SECTOR_SIZE;
+ lim->io_min = SECTOR_SIZE;
+ lim->discard_granularity = SECTOR_SIZE;
+ lim->dma_alignment = SECTOR_SIZE - 1;
+ lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
/* Inherit limits from component devices */
lim->max_segments = USHRT_MAX;
lim->max_dev_sectors = UINT_MAX;
lim->max_write_zeroes_sectors = UINT_MAX;
lim->max_zone_append_sectors = UINT_MAX;
+ lim->max_user_discard_sectors = UINT_MAX;
}
EXPORT_SYMBOL(blk_set_stacking_limits);
+static void blk_apply_bdi_limits(struct backing_dev_info *bdi,
+ struct queue_limits *lim)
+{
+ /*
+ * For read-ahead of large files to be effective, we need to read ahead
+ * at least twice the optimal I/O size.
+ */
+ bdi->ra_pages = max(lim->io_opt * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
+ bdi->io_pages = lim->max_sectors >> PAGE_SECTORS_SHIFT;
+}
+
+static int blk_validate_zoned_limits(struct queue_limits *lim)
+{
+ if (!lim->zoned) {
+ if (WARN_ON_ONCE(lim->max_open_zones) ||
+ WARN_ON_ONCE(lim->max_active_zones) ||
+ WARN_ON_ONCE(lim->zone_write_granularity) ||
+ WARN_ON_ONCE(lim->max_zone_append_sectors))
+ return -EINVAL;
+ return 0;
+ }
+
+ if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_BLK_DEV_ZONED)))
+ return -EINVAL;
+
+ if (lim->zone_write_granularity < lim->logical_block_size)
+ lim->zone_write_granularity = lim->logical_block_size;
+
+ if (lim->max_zone_append_sectors) {
+ /*
+ * The Zone Append size is limited by the maximum I/O size
+ * and the zone size given that it can't span zones.
+ */
+ lim->max_zone_append_sectors =
+ min3(lim->max_hw_sectors,
+ lim->max_zone_append_sectors,
+ lim->chunk_sectors);
+ }
+
+ return 0;
+}
+
+/*
+ * Check that the limits in lim are valid, initialize defaults for unset
+ * values, and cap values based on others where needed.
+ */
+static int blk_validate_limits(struct queue_limits *lim)
+{
+ unsigned int max_hw_sectors;
+
+ /*
+ * Unless otherwise specified, default to 512 byte logical blocks and a
+ * physical block size equal to the logical block size.
+ */
+ if (!lim->logical_block_size)
+ lim->logical_block_size = SECTOR_SIZE;
+ if (lim->physical_block_size < lim->logical_block_size)
+ lim->physical_block_size = lim->logical_block_size;
+
+ /*
+ * The minimum I/O size defaults to the physical block size unless
+ * explicitly overridden.
+ */
+ if (lim->io_min < lim->physical_block_size)
+ lim->io_min = lim->physical_block_size;
+
+ /*
+ * max_hw_sectors has a somewhat weird default for historical reason,
+ * but driver really should set their own instead of relying on this
+ * value.
+ *
+ * The block layer relies on the fact that every driver can
+ * handle at lest a page worth of data per I/O, and needs the value
+ * aligned to the logical block size.
+ */
+ if (!lim->max_hw_sectors)
+ lim->max_hw_sectors = BLK_SAFE_MAX_SECTORS;
+ if (WARN_ON_ONCE(lim->max_hw_sectors < PAGE_SECTORS))
+ return -EINVAL;
+ lim->max_hw_sectors = round_down(lim->max_hw_sectors,
+ lim->logical_block_size >> SECTOR_SHIFT);
+
+ /*
+ * The actual max_sectors value is a complex beast and also takes the
+ * max_dev_sectors value (set by SCSI ULPs) and a user configurable
+ * value into account. The ->max_sectors value is always calculated
+ * from these, so directly setting it won't have any effect.
+ */
+ max_hw_sectors = min_not_zero(lim->max_hw_sectors,
+ lim->max_dev_sectors);
+ if (lim->max_user_sectors) {
+ if (lim->max_user_sectors < PAGE_SIZE / SECTOR_SIZE)
+ return -EINVAL;
+ lim->max_sectors = min(max_hw_sectors, lim->max_user_sectors);
+ } else {
+ lim->max_sectors = min(max_hw_sectors, BLK_DEF_MAX_SECTORS_CAP);
+ }
+ lim->max_sectors = round_down(lim->max_sectors,
+ lim->logical_block_size >> SECTOR_SHIFT);
+
+ /*
+ * Random default for the maximum number of segments. Driver should not
+ * rely on this and set their own.
+ */
+ if (!lim->max_segments)
+ lim->max_segments = BLK_MAX_SEGMENTS;
+
+ lim->max_discard_sectors =
+ min(lim->max_hw_discard_sectors, lim->max_user_discard_sectors);
+
+ if (!lim->max_discard_segments)
+ lim->max_discard_segments = 1;
+
+ if (lim->discard_granularity < lim->physical_block_size)
+ lim->discard_granularity = lim->physical_block_size;
+
+ /*
+ * By default there is no limit on the segment boundary alignment,
+ * but if there is one it can't be smaller than the page size as
+ * that would break all the normal I/O patterns.
+ */
+ if (!lim->seg_boundary_mask)
+ lim->seg_boundary_mask = BLK_SEG_BOUNDARY_MASK;
+ if (WARN_ON_ONCE(lim->seg_boundary_mask < PAGE_SIZE - 1))
+ return -EINVAL;
+
+ /*
+ * Stacking device may have both virtual boundary and max segment
+ * size limit, so allow this setting now, and long-term the two
+ * might need to move out of stacking limits since we have immutable
+ * bvec and lower layer bio splitting is supposed to handle the two
+ * correctly.
+ */
+ if (!lim->virt_boundary_mask) {
+ /*
+ * The maximum segment size has an odd historic 64k default that
+ * drivers probably should override. Just like the I/O size we
+ * require drivers to at least handle a full page per segment.
+ */
+ if (!lim->max_segment_size)
+ lim->max_segment_size = BLK_MAX_SEGMENT_SIZE;
+ if (WARN_ON_ONCE(lim->max_segment_size < PAGE_SIZE))
+ return -EINVAL;
+ }
+
+ /*
+ * We require drivers to at least do logical block aligned I/O, but
+ * historically could not check for that due to the separate calls
+ * to set the limits. Once the transition is finished the check
+ * below should be narrowed down to check the logical block size.
+ */
+ if (!lim->dma_alignment)
+ lim->dma_alignment = SECTOR_SIZE - 1;
+ if (WARN_ON_ONCE(lim->dma_alignment > PAGE_SIZE))
+ return -EINVAL;
+
+ if (lim->alignment_offset) {
+ lim->alignment_offset &= (lim->physical_block_size - 1);
+ lim->misaligned = 0;
+ }
+
+ return blk_validate_zoned_limits(lim);
+}
+
+/*
+ * Set the default limits for a newly allocated queue. @lim contains the
+ * initial limits set by the driver, which could be no limit in which case
+ * all fields are cleared to zero.
+ */
+int blk_set_default_limits(struct queue_limits *lim)
+{
+ /*
+ * Most defaults are set by capping the bounds in blk_validate_limits,
+ * but max_user_discard_sectors is special and needs an explicit
+ * initialization to the max value here.
+ */
+ lim->max_user_discard_sectors = UINT_MAX;
+ return blk_validate_limits(lim);
+}
+
+/**
+ * queue_limits_commit_update - commit an atomic update of queue limits
+ * @q: queue to update
+ * @lim: limits to apply
+ *
+ * Apply the limits in @lim that were obtained from queue_limits_start_update()
+ * and updated by the caller to @q.
+ *
+ * Returns 0 if successful, else a negative error code.
+ */
+int queue_limits_commit_update(struct request_queue *q,
+ struct queue_limits *lim)
+ __releases(q->limits_lock)
+{
+ int error = blk_validate_limits(lim);
+
+ if (!error) {
+ q->limits = *lim;
+ if (q->disk)
+ blk_apply_bdi_limits(q->disk->bdi, lim);
+ }
+ mutex_unlock(&q->limits_lock);
+ return error;
+}
+EXPORT_SYMBOL_GPL(queue_limits_commit_update);
+
+/**
+ * queue_limits_set - apply queue limits to queue
+ * @q: queue to update
+ * @lim: limits to apply
+ *
+ * Apply the limits in @lim that were freshly initialized to @q.
+ * To update existing limits use queue_limits_start_update() and
+ * queue_limits_commit_update() instead.
+ *
+ * Returns 0 if successful, else a negative error code.
+ */
+int queue_limits_set(struct request_queue *q, struct queue_limits *lim)
+{
+ mutex_lock(&q->limits_lock);
+ return queue_limits_commit_update(q, lim);
+}
+EXPORT_SYMBOL_GPL(queue_limits_set);
+
/**
* blk_queue_bounce_limit - set bounce buffer limit for queue
* @q: the request queue for the device
void blk_queue_max_discard_sectors(struct request_queue *q,
unsigned int max_discard_sectors)
{
- q->limits.max_hw_discard_sectors = max_discard_sectors;
- q->limits.max_discard_sectors = max_discard_sectors;
+ struct queue_limits *lim = &q->limits;
+
+ lim->max_hw_discard_sectors = max_discard_sectors;
+ lim->max_discard_sectors =
+ min(max_discard_sectors, lim->max_user_discard_sectors);
}
EXPORT_SYMBOL(blk_queue_max_discard_sectors);
void disk_update_readahead(struct gendisk *disk)
{
- struct request_queue *q = disk->queue;
-
- /*
- * For read-ahead of large files to be effective, we need to read ahead
- * at least twice the optimal I/O size.
- */
- disk->bdi->ra_pages =
- max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
- disk->bdi->io_pages = queue_max_sectors(q) >> (PAGE_SHIFT - 9);
+ blk_apply_bdi_limits(disk->bdi, &disk->queue->limits);
}
EXPORT_SYMBOL_GPL(disk_update_readahead);
t->zone_write_granularity = max(t->zone_write_granularity,
b->zone_write_granularity);
t->zoned = max(t->zoned, b->zoned);
+ if (!t->zoned) {
+ t->zone_write_granularity = 0;
+ t->max_zone_append_sectors = 0;
+ }
return ret;
}
EXPORT_SYMBOL(blk_stack_limits);
/**
- * disk_stack_limits - adjust queue limits for stacked drivers
- * @disk: MD/DM gendisk (top)
+ * queue_limits_stack_bdev - adjust queue_limits for stacked devices
+ * @t: the stacking driver limits (top device)
* @bdev: the underlying block device (bottom)
* @offset: offset to beginning of data within component device
+ * @pfx: prefix to use for warnings logged
*
* Description:
- * Merges the limits for a top level gendisk and a bottom level
- * block_device.
+ * This function is used by stacking drivers like MD and DM to ensure
+ * that all component devices have compatible block sizes and
+ * alignments. The stacking driver must provide a queue_limits
+ * struct (top) and then iteratively call the stacking function for
+ * all component (bottom) devices. The stacking function will
+ * attempt to combine the values and ensure proper alignment.
*/
-void disk_stack_limits(struct gendisk *disk, struct block_device *bdev,
- sector_t offset)
+void queue_limits_stack_bdev(struct queue_limits *t, struct block_device *bdev,
+ sector_t offset, const char *pfx)
{
- struct request_queue *t = disk->queue;
-
- if (blk_stack_limits(&t->limits, &bdev_get_queue(bdev)->limits,
- get_start_sect(bdev) + (offset >> 9)) < 0)
+ if (blk_stack_limits(t, &bdev_get_queue(bdev)->limits,
+ get_start_sect(bdev) + offset))
pr_notice("%s: Warning: Device %pg is misaligned\n",
- disk->disk_name, bdev);
-
- disk_update_readahead(disk);
+ pfx, bdev);
}
-EXPORT_SYMBOL(disk_stack_limits);
+EXPORT_SYMBOL_GPL(queue_limits_stack_bdev);
/**
* blk_queue_update_dma_pad - update pad mask
projects / linux-block.git / blobdiff