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-rw-r--r--drivers/md/raid5-cache.c243
1 files changed, 240 insertions, 3 deletions
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c
index a42f522f52e7..2b9ed0e3af37 100644
--- a/drivers/md/raid5-cache.c
+++ b/drivers/md/raid5-cache.c
@@ -717,11 +717,248 @@ static void r5l_wake_reclaim(struct r5l_log *log, sector_t space)
md_wakeup_thread(log->reclaim_thread);
}
+struct r5l_recovery_ctx {
+ struct page *meta_page; /* current meta */
+ sector_t meta_total_blocks; /* total size of current meta and data */
+ sector_t pos; /* recovery position */
+ u64 seq; /* recovery position seq */
+};
+
+static int r5l_read_meta_block(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx)
+{
+ struct page *page = ctx->meta_page;
+ struct r5l_meta_block *mb;
+ u32 crc, stored_crc;
+
+ if (!sync_page_io(log->rdev, ctx->pos, PAGE_SIZE, page, READ, false))
+ return -EIO;
+
+ mb = page_address(page);
+ stored_crc = le32_to_cpu(mb->checksum);
+ mb->checksum = 0;
+
+ if (le32_to_cpu(mb->magic) != R5LOG_MAGIC ||
+ le64_to_cpu(mb->seq) != ctx->seq ||
+ mb->version != R5LOG_VERSION ||
+ le64_to_cpu(mb->position) != ctx->pos)
+ return -EINVAL;
+
+ crc = crc32_le(log->uuid_checksum, (void *)mb, PAGE_SIZE);
+ if (stored_crc != crc)
+ return -EINVAL;
+
+ if (le32_to_cpu(mb->meta_size) > PAGE_SIZE)
+ return -EINVAL;
+
+ ctx->meta_total_blocks = BLOCK_SECTORS;
+
+ return 0;
+}
+
+static int r5l_recovery_flush_one_stripe(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx,
+ sector_t stripe_sect,
+ int *offset, sector_t *log_offset)
+{
+ struct r5conf *conf = log->rdev->mddev->private;
+ struct stripe_head *sh;
+ struct r5l_payload_data_parity *payload;
+ int disk_index;
+
+ sh = raid5_get_active_stripe(conf, stripe_sect, 0, 0, 0);
+ while (1) {
+ payload = page_address(ctx->meta_page) + *offset;
+
+ if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_DATA) {
+ raid5_compute_sector(conf,
+ le64_to_cpu(payload->location), 0,
+ &disk_index, sh);
+
+ sync_page_io(log->rdev, *log_offset, PAGE_SIZE,
+ sh->dev[disk_index].page, READ, false);
+ sh->dev[disk_index].log_checksum =
+ le32_to_cpu(payload->checksum[0]);
+ set_bit(R5_Wantwrite, &sh->dev[disk_index].flags);
+ ctx->meta_total_blocks += BLOCK_SECTORS;
+ } else {
+ disk_index = sh->pd_idx;
+ sync_page_io(log->rdev, *log_offset, PAGE_SIZE,
+ sh->dev[disk_index].page, READ, false);
+ sh->dev[disk_index].log_checksum =
+ le32_to_cpu(payload->checksum[0]);
+ set_bit(R5_Wantwrite, &sh->dev[disk_index].flags);
+
+ if (sh->qd_idx >= 0) {
+ disk_index = sh->qd_idx;
+ sync_page_io(log->rdev,
+ r5l_ring_add(log, *log_offset, BLOCK_SECTORS),
+ PAGE_SIZE, sh->dev[disk_index].page,
+ READ, false);
+ sh->dev[disk_index].log_checksum =
+ le32_to_cpu(payload->checksum[1]);
+ set_bit(R5_Wantwrite,
+ &sh->dev[disk_index].flags);
+ }
+ ctx->meta_total_blocks += BLOCK_SECTORS * conf->max_degraded;
+ }
+
+ *log_offset = r5l_ring_add(log, *log_offset,
+ le32_to_cpu(payload->size));
+ *offset += sizeof(struct r5l_payload_data_parity) +
+ sizeof(__le32) *
+ (le32_to_cpu(payload->size) >> (PAGE_SHIFT - 9));
+ if (le16_to_cpu(payload->header.type) == R5LOG_PAYLOAD_PARITY)
+ break;
+ }
+
+ for (disk_index = 0; disk_index < sh->disks; disk_index++) {
+ void *addr;
+ u32 checksum;
+
+ if (!test_bit(R5_Wantwrite, &sh->dev[disk_index].flags))
+ continue;
+ addr = kmap_atomic(sh->dev[disk_index].page);
+ checksum = crc32_le(log->uuid_checksum, addr, PAGE_SIZE);
+ kunmap_atomic(addr);
+ if (checksum != sh->dev[disk_index].log_checksum)
+ goto error;
+ }
+
+ for (disk_index = 0; disk_index < sh->disks; disk_index++) {
+ struct md_rdev *rdev, *rrdev;
+
+ if (!test_and_clear_bit(R5_Wantwrite,
+ &sh->dev[disk_index].flags))
+ continue;
+
+ /* in case device is broken */
+ rdev = rcu_dereference(conf->disks[disk_index].rdev);
+ if (rdev)
+ sync_page_io(rdev, stripe_sect, PAGE_SIZE,
+ sh->dev[disk_index].page, WRITE, false);
+ rrdev = rcu_dereference(conf->disks[disk_index].replacement);
+ if (rrdev)
+ sync_page_io(rrdev, stripe_sect, PAGE_SIZE,
+ sh->dev[disk_index].page, WRITE, false);
+ }
+ raid5_release_stripe(sh);
+ return 0;
+
+error:
+ for (disk_index = 0; disk_index < sh->disks; disk_index++)
+ sh->dev[disk_index].flags = 0;
+ raid5_release_stripe(sh);
+ return -EINVAL;
+}
+
+static int r5l_recovery_flush_one_meta(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx)
+{
+ struct r5conf *conf = log->rdev->mddev->private;
+ struct r5l_payload_data_parity *payload;
+ struct r5l_meta_block *mb;
+ int offset;
+ sector_t log_offset;
+ sector_t stripe_sector;
+
+ mb = page_address(ctx->meta_page);
+ offset = sizeof(struct r5l_meta_block);
+ log_offset = r5l_ring_add(log, ctx->pos, BLOCK_SECTORS);
+
+ while (offset < le32_to_cpu(mb->meta_size)) {
+ int dd;
+
+ payload = (void *)mb + offset;
+ stripe_sector = raid5_compute_sector(conf,
+ le64_to_cpu(payload->location), 0, &dd, NULL);
+ if (r5l_recovery_flush_one_stripe(log, ctx, stripe_sector,
+ &offset, &log_offset))
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/* copy data/parity from log to raid disks */
+static void r5l_recovery_flush_log(struct r5l_log *log,
+ struct r5l_recovery_ctx *ctx)
+{
+ while (1) {
+ if (r5l_read_meta_block(log, ctx))
+ return;
+ if (r5l_recovery_flush_one_meta(log, ctx))
+ return;
+ ctx->seq++;
+ ctx->pos = r5l_ring_add(log, ctx->pos, ctx->meta_total_blocks);
+ }
+}
+
+static int r5l_log_write_empty_meta_block(struct r5l_log *log, sector_t pos,
+ u64 seq)
+{
+ struct page *page;
+ struct r5l_meta_block *mb;
+ u32 crc;
+
+ page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!page)
+ return -ENOMEM;
+ mb = page_address(page);
+ mb->magic = cpu_to_le32(R5LOG_MAGIC);
+ mb->version = R5LOG_VERSION;
+ mb->meta_size = cpu_to_le32(sizeof(struct r5l_meta_block));
+ mb->seq = cpu_to_le64(seq);
+ mb->position = cpu_to_le64(pos);
+ crc = crc32_le(log->uuid_checksum, (void *)mb, PAGE_SIZE);
+ mb->checksum = cpu_to_le32(crc);
+
+ if (!sync_page_io(log->rdev, pos, PAGE_SIZE, page, WRITE_FUA, false)) {
+ __free_page(page);
+ return -EIO;
+ }
+ __free_page(page);
+ return 0;
+}
+
static int r5l_recovery_log(struct r5l_log *log)
{
- /* fake recovery */
- log->seq = log->last_cp_seq + 1;
- log->log_start = r5l_ring_add(log, log->last_checkpoint, BLOCK_SECTORS);
+ struct r5l_recovery_ctx ctx;
+
+ ctx.pos = log->last_checkpoint;
+ ctx.seq = log->last_cp_seq;
+ ctx.meta_page = alloc_page(GFP_KERNEL);
+ if (!ctx.meta_page)
+ return -ENOMEM;
+
+ r5l_recovery_flush_log(log, &ctx);
+ __free_page(ctx.meta_page);
+
+ /*
+ * we did a recovery. Now ctx.pos points to an invalid meta block. New
+ * log will start here. but we can't let superblock point to last valid
+ * meta block. The log might looks like:
+ * | meta 1| meta 2| meta 3|
+ * meta 1 is valid, meta 2 is invalid. meta 3 could be valid. If
+ * superblock points to meta 1, we write a new valid meta 2n. if crash
+ * happens again, new recovery will start from meta 1. Since meta 2n is
+ * valid now, recovery will think meta 3 is valid, which is wrong.
+ * The solution is we create a new meta in meta2 with its seq == meta
+ * 1's seq + 10 and let superblock points to meta2. The same recovery will
+ * not think meta 3 is a valid meta, because its seq doesn't match
+ */
+ if (ctx.seq > log->last_cp_seq + 1) {
+ int ret;
+
+ ret = r5l_log_write_empty_meta_block(log, ctx.pos, ctx.seq + 10);
+ if (ret)
+ return ret;
+ log->seq = ctx.seq + 11;
+ log->log_start = r5l_ring_add(log, ctx.pos, BLOCK_SECTORS);
+ r5l_write_super(log, ctx.pos);
+ } else {
+ log->log_start = ctx.pos;
+ log->seq = ctx.seq;
+ }
return 0;
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-15 19:20:42 +0000