[PATCH 16/21] xfs: add data checksum support to zoned garbage collection

[Christoph Hellwig <hch@lst.de>]

Transfer the checksum from the old location to the new one.  The
implementation mirrors that of user data reads and writes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 fs/xfs/xfs_zone_gc.c | 65 ++++++++++++++++++++++++++++++++++++--------
 1 file changed, 53 insertions(+), 12 deletions(-)

diff --git a/fs/xfs/xfs_zone_gc.c b/fs/xfs/xfs_zone_gc.c
index 5fdcf98a2133..1cebd2ee2136 100644
--- a/fs/xfs/xfs_zone_gc.c
+++ b/fs/xfs/xfs_zone_gc.c
@@ -21,6 +21,7 @@
 #include "xfs_zone_alloc.h"
 #include "xfs_zone_priv.h"
 #include "xfs_zones.h"
+#include "xfs_rtcsum.h"
 #include "xfs_trace.h"
 
 /*
@@ -106,6 +107,10 @@ struct xfs_gc_bio {
 	/* Realtime group currently being reclaimed */
 	struct xfs_rtgroup		*victim_rtg;
 
+	/* Buffer for data checksums */
+	struct xfs_buf			*csum_bp;
+	void				*csum_buf;
+
 	/* Bio used for reads and writes, including the bvec used by it */
 	struct bio			bio;	/* must be last */
 };
@@ -660,6 +665,20 @@ xfs_zone_gc_alloc_blocks(
 	return true;
 }
 
+static void
+xfs_zone_gc_free_chunk(
+	struct xfs_gc_bio	*chunk)
+{
+	atomic_dec(&chunk->victim_rtg->rtg_gccount);
+	xfs_rtgroup_rele(chunk->victim_rtg);
+	list_del(&chunk->entry);
+	xfs_open_zone_put(chunk->oz);
+	if (chunk->csum_bp)
+		xfs_buf_rele(chunk->csum_bp);
+	xfs_irele(chunk->ip);
+	bio_put(&chunk->bio);
+}
+
 static void
 xfs_zone_gc_add_data(
 	struct xfs_gc_bio	*chunk)
@@ -725,6 +744,11 @@ xfs_zone_gc_start_chunk(
 	if (!xfs_zone_gc_iter_irec(mp, iter, &irec, &ip))
 		return false;
 
+	if (xfs_has_rtcsum(mp)) {
+		irec.rm_blockcount = min(irec.rm_blockcount,
+			xfs_rtcsum_max_len(mp, irec.rm_startblock));
+	}
+
 	if (!xfs_zone_gc_alloc_blocks(data, &irec.rm_blockcount, &daddr,
 			&is_seq)) {
 		xfs_irele(ip);
@@ -748,6 +772,7 @@ xfs_zone_gc_start_chunk(
 	chunk->data = data;
 	chunk->oz = data->oz;
 	chunk->victim_rtg = iter->victim_rtg;
+	chunk->csum_bp = NULL;
 	atomic_inc(&rtg_group(chunk->victim_rtg)->xg_active_ref);
 	atomic_inc(&chunk->victim_rtg->rtg_gccount);
 
@@ -764,22 +789,22 @@ xfs_zone_gc_start_chunk(
 	list_add_tail(&chunk->entry, &data->reading);
 	xfs_zone_gc_iter_advance(iter, irec.rm_blockcount);
 
+	if (xfs_is_rtcsum_inode(ip)) {
+		int error;
+
+		error = xfs_rtcsum_read_async(mp, chunk->old_startblock,
+				&chunk->csum_bp);
+		if (error) {
+			xfs_force_shutdown(mp, SHUTDOWN_META_IO_ERROR);
+			xfs_zone_gc_free_chunk(chunk);
+			return false;
+		}
+	}
+
 	submit_bio(bio);
 	return true;
 }
 
-static void
-xfs_zone_gc_free_chunk(
-	struct xfs_gc_bio	*chunk)
-{
-	atomic_dec(&chunk->victim_rtg->rtg_gccount);
-	xfs_rtgroup_rele(chunk->victim_rtg);
-	list_del(&chunk->entry);
-	xfs_open_zone_put(chunk->oz);
-	xfs_irele(chunk->ip);
-	bio_put(&chunk->bio);
-}
-
 static void
 xfs_zone_gc_submit_write(
 	struct xfs_zone_gc_data	*data,
@@ -832,6 +857,9 @@ xfs_zone_gc_split_write(
 	split_chunk->old_startblock = chunk->old_startblock;
 	split_chunk->new_daddr = chunk->new_daddr;
 	split_chunk->oz = chunk->oz;
+	split_chunk->csum_bp = chunk->csum_bp;
+	if (split_chunk->csum_bp)
+		xfs_buf_hold(split_chunk->csum_bp);
 	atomic_inc(&chunk->oz->oz_ref);
 
 	split_chunk->victim_rtg = chunk->victim_rtg;
@@ -919,6 +947,19 @@ xfs_zone_gc_finish_chunk(
 
 	if (chunk->is_seq)
 		chunk->new_daddr = chunk->bio.bi_iter.bi_sector;
+
+	if (xfs_is_rtcsum_inode(ip)) {
+		unsigned int	boff;
+
+		error = xfs_buf_read_async_wait(chunk->csum_bp);
+		if (error)
+			goto free;
+
+		boff = xfs_rtb_to_rtcsumoff(mp, chunk->old_startblock);
+		error = xfs_rtcsum_log(chunk->oz, chunk->new_daddr, chunk->len,
+				chunk->csum_bp->b_addr + boff);
+	}
+
 	error = xfs_zoned_end_io(ip, chunk->offset, chunk->len,
 			chunk->new_daddr, chunk->oz, chunk->old_startblock);
 free:
-- 
2.53.0