bcachefs: fix fallocate + compression

2 files changed, 29 insertions, 6 deletions

diff --git a/drivers/md/bcache/extents.h b/drivers/md/bcache/extents.h
index 42db3d1ca933..e861492c731e 100644
--- a/drivers/md/bcache/extents.h
+++ b/drivers/md/bcache/extents.h
@@ -354,6 +354,29 @@ static inline struct bch_extent_crc64 crc_to_64(const union bch_extent_crc *crc)
 	}
 }
 
+static inline bool bkey_extent_is_compressed(struct cache_set *c,
+					     struct bkey_s_c k)
+{
+	struct bkey_s_c_extent e;
+	const struct bch_extent_ptr *ptr;
+	const union bch_extent_crc *crc;
+
+	switch (k.k->type) {
+	case BCH_EXTENT:
+	case BCH_EXTENT_CACHED:
+		e = bkey_s_c_to_extent(k);
+
+		extent_for_each_ptr_crc(e, ptr, crc)
+			if (bch_extent_ptr_is_dirty(c, e, ptr) &&
+			    crc_to_64(crc).compression_type != BCH_COMPRESSION_NONE &&
+			    crc_to_64(crc).compressed_size < k.k->size)
+				return true;
+		return true;
+	default:
+		return false;
+	}
+}
+
 void extent_adjust_pointers(struct bkey_s_extent, union bch_extent_entry *);
 
 /* Doesn't cleanup redundant crcs */
diff --git a/drivers/md/bcache/fs-io.c b/drivers/md/bcache/fs-io.c
index 5c8ff61cee69..0ffe10fb0b98 100644
--- a/drivers/md/bcache/fs-io.c
+++ b/drivers/md/bcache/fs-io.c
@@ -699,6 +699,10 @@ static void bchfs_read(struct cache_set *c, struct bch_read_bio *rbio, u64 inode
 		unsigned bytes, sectors;
 		bool is_last;
 
+		if (!bkey_extent_is_allocation(k.k) ||
+		    bkey_extent_is_compressed(c, k))
+			bch_mark_pages_unalloc(bio);
+
 		bch_extent_pick_ptr(c, k, &pick);
 		bch_btree_iter_unlock(&iter);
 
@@ -715,11 +719,6 @@ static void bchfs_read(struct cache_set *c, struct bch_read_bio *rbio, u64 inode
 		is_last = bytes == bio->bi_iter.bi_size;
 		swap(bio->bi_iter.bi_size, bytes);
 
-		if (!(k.k->type == BCH_RESERVATION ||
-		      (pick.ca &&
-		       pick.crc.compression_type == BCH_COMPRESSION_NONE)))
-			bch_mark_pages_unalloc(bio);
-
 		if (bkey_extent_is_allocation(k.k))
 			bch_add_page_sectors(bio, k.k);
 
@@ -2350,7 +2349,8 @@ static long bch_fallocate(struct inode *inode, int mode,
 
 		sectors = reservation.k.size;
 
-		if (!bkey_extent_is_allocation(k.k)) {
+		if (!bkey_extent_is_allocation(k.k) ||
+		    bkey_extent_is_compressed(c, k)) {
 			ret = bch_disk_reservation_get(c, &disk_res, sectors);
 			if (ret)
 				goto err_put_sectors_dirty;