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-rw-r--r--block/blk-zoned.c257
1 files changed, 257 insertions, 0 deletions
diff --git a/block/blk-zoned.c b/block/blk-zoned.c
new file mode 100644
index 000000000000..1603573f9605
--- /dev/null
+++ b/block/blk-zoned.c
@@ -0,0 +1,257 @@
+/*
+ * Zoned block device handling
+ *
+ * Copyright (c) 2015, Hannes Reinecke
+ * Copyright (c) 2015, SUSE Linux GmbH
+ *
+ * Copyright (c) 2016, Damien Le Moal
+ * Copyright (c) 2016, Western Digital
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rbtree.h>
+#include <linux/blkdev.h>
+
+static inline sector_t blk_zone_start(struct request_queue *q,
+ sector_t sector)
+{
+ sector_t zone_mask = blk_queue_zone_size(q) - 1;
+
+ return sector & ~zone_mask;
+}
+
+/*
+ * Check that a zone report belongs to the partition.
+ * If yes, fix its start sector and write pointer, copy it in the
+ * zone information array and return true. Return false otherwise.
+ */
+static bool blkdev_report_zone(struct block_device *bdev,
+ struct blk_zone *rep,
+ struct blk_zone *zone)
+{
+ sector_t offset = get_start_sect(bdev);
+
+ if (rep->start < offset)
+ return false;
+
+ rep->start -= offset;
+ if (rep->start + rep->len > bdev->bd_part->nr_sects)
+ return false;
+
+ if (rep->type == BLK_ZONE_TYPE_CONVENTIONAL)
+ rep->wp = rep->start + rep->len;
+ else
+ rep->wp -= offset;
+ memcpy(zone, rep, sizeof(struct blk_zone));
+
+ return true;
+}
+
+/**
+ * blkdev_report_zones - Get zones information
+ * @bdev: Target block device
+ * @sector: Sector from which to report zones
+ * @zones: Array of zone structures where to return the zones information
+ * @nr_zones: Number of zone structures in the zone array
+ * @gfp_mask: Memory allocation flags (for bio_alloc)
+ *
+ * Description:
+ * Get zone information starting from the zone containing @sector.
+ * The number of zone information reported may be less than the number
+ * requested by @nr_zones. The number of zones actually reported is
+ * returned in @nr_zones.
+ */
+int blkdev_report_zones(struct block_device *bdev,
+ sector_t sector,
+ struct blk_zone *zones,
+ unsigned int *nr_zones,
+ gfp_t gfp_mask)
+{
+ struct request_queue *q = bdev_get_queue(bdev);
+ struct blk_zone_report_hdr *hdr;
+ unsigned int nrz = *nr_zones;
+ struct page *page;
+ unsigned int nr_rep;
+ size_t rep_bytes;
+ unsigned int nr_pages;
+ struct bio *bio;
+ struct bio_vec *bv;
+ unsigned int i, n, nz;
+ unsigned int ofst;
+ void *addr;
+ int ret = 0;
+
+ if (!q)
+ return -ENXIO;
+
+ if (!blk_queue_is_zoned(q))
+ return -EOPNOTSUPP;
+
+ if (!nrz)
+ return 0;
+
+ if (sector > bdev->bd_part->nr_sects) {
+ *nr_zones = 0;
+ return 0;
+ }
+
+ /*
+ * The zone report has a header. So make room for it in the
+ * payload. Also make sure that the report fits in a single BIO
+ * that will not be split down the stack.
+ */
+ rep_bytes = sizeof(struct blk_zone_report_hdr) +
+ sizeof(struct blk_zone) * nrz;
+ rep_bytes = (rep_bytes + PAGE_SIZE - 1) & PAGE_MASK;
+ if (rep_bytes > (queue_max_sectors(q) << 9))
+ rep_bytes = queue_max_sectors(q) << 9;
+
+ nr_pages = min_t(unsigned int, BIO_MAX_PAGES,
+ rep_bytes >> PAGE_SHIFT);
+ nr_pages = min_t(unsigned int, nr_pages,
+ queue_max_segments(q));
+
+ bio = bio_alloc(gfp_mask, nr_pages);
+ if (!bio)
+ return -ENOMEM;
+
+ bio->bi_bdev = bdev;
+ bio->bi_iter.bi_sector = blk_zone_start(q, sector);
+ bio_set_op_attrs(bio, REQ_OP_ZONE_REPORT, 0);
+
+ for (i = 0; i < nr_pages; i++) {
+ page = alloc_page(gfp_mask);
+ if (!page) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ if (!bio_add_page(bio, page, PAGE_SIZE, 0)) {
+ __free_page(page);
+ break;
+ }
+ }
+
+ if (i == 0)
+ ret = -ENOMEM;
+ else
+ ret = submit_bio_wait(bio);
+ if (ret)
+ goto out;
+
+ /*
+ * Process the report result: skip the header and go through the
+ * reported zones to fixup and fixup the zone information for
+ * partitions. At the same time, return the zone information into
+ * the zone array.
+ */
+ n = 0;
+ nz = 0;
+ nr_rep = 0;
+ bio_for_each_segment_all(bv, bio, i) {
+
+ if (!bv->bv_page)
+ break;
+
+ addr = kmap_atomic(bv->bv_page);
+
+ /* Get header in the first page */
+ ofst = 0;
+ if (!nr_rep) {
+ hdr = (struct blk_zone_report_hdr *) addr;
+ nr_rep = hdr->nr_zones;
+ ofst = sizeof(struct blk_zone_report_hdr);
+ }
+
+ /* Fixup and report zones */
+ while (ofst < bv->bv_len &&
+ n < nr_rep && nz < nrz) {
+ if (blkdev_report_zone(bdev, addr + ofst, &zones[nz]))
+ nz++;
+ ofst += sizeof(struct blk_zone);
+ n++;
+ }
+
+ kunmap_atomic(addr);
+
+ if (n >= nr_rep || nz >= nrz)
+ break;
+
+ }
+
+out:
+ bio_for_each_segment_all(bv, bio, i)
+ __free_page(bv->bv_page);
+ bio_put(bio);
+
+ if (ret == 0)
+ *nr_zones = nz;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(blkdev_report_zones);
+
+/**
+ * blkdev_reset_zones - Reset zones write pointer
+ * @bdev: Target block device
+ * @sector: Start sector of the first zone to reset
+ * @nr_sectors: Number of sectors, at least the length of one zone
+ * @gfp_mask: Memory allocation flags (for bio_alloc)
+ *
+ * Description:
+ * Reset the write pointer of the zones contained in the range
+ * @sector..@sector+@nr_sectors. Specifying the entire disk sector range
+ * is valid, but the specified range should not contain conventional zones.
+ */
+int blkdev_reset_zones(struct block_device *bdev,
+ sector_t sector, sector_t nr_sectors,
+ gfp_t gfp_mask)
+{
+ struct request_queue *q = bdev_get_queue(bdev);
+ sector_t zone_sectors;
+ sector_t end_sector = sector + nr_sectors;
+ struct bio *bio;
+ int ret;
+
+ if (!q)
+ return -ENXIO;
+
+ if (!blk_queue_is_zoned(q))
+ return -EOPNOTSUPP;
+
+ if (end_sector > bdev->bd_part->nr_sects)
+ /* Out of range */
+ return -EINVAL;
+
+ /* Check alignment (handle eventual smaller last zone) */
+ zone_sectors = blk_queue_zone_size(q);
+ if (sector & (zone_sectors - 1))
+ return -EINVAL;
+
+ if ((nr_sectors & (zone_sectors - 1)) &&
+ end_sector != bdev->bd_part->nr_sects)
+ return -EINVAL;
+
+ while (sector < end_sector) {
+
+ bio = bio_alloc(gfp_mask, 0);
+ bio->bi_iter.bi_sector = sector;
+ bio->bi_bdev = bdev;
+ bio_set_op_attrs(bio, REQ_OP_ZONE_RESET, 0);
+
+ ret = submit_bio_wait(bio);
+ bio_put(bio);
+
+ if (ret)
+ return ret;
+
+ sector += zone_sectors;
+
+ /* This may take a while, so be nice to others */
+ cond_resched();
+
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(blkdev_reset_zones);