[PATCH] erofs-utils: mkfs: add block list support for chunked files

[David Anderson]

When using the --block-list-file option, add block mapping lines for
chunked files. The extent printing code has been slightly refactored to
accommodate multiple extent ranges.

Signed-off-by: David Anderson <dvander at google.com>
---
 include/erofs/block_list.h |  7 +++++++
 lib/blobchunk.c            | 27 ++++++++++++++++++++++++-
 lib/block_list.c           | 41 +++++++++++++++++++++++++++++---------
 3 files changed, 65 insertions(+), 10 deletions(-)

diff --git a/include/erofs/block_list.h b/include/erofs/block_list.h
index dcc0e50..40df228 100644
--- a/include/erofs/block_list.h
+++ b/include/erofs/block_list.h
@@ -15,11 +15,18 @@ void erofs_droid_blocklist_write(struct erofs_inode *inode,
 				 erofs_blk_t blk_start, erofs_blk_t nblocks);
 void erofs_droid_blocklist_write_tail_end(struct erofs_inode *inode,
 					  erofs_blk_t blkaddr);
+void erofs_droid_blocklist_write_extent(struct erofs_inode *inode,
+					erofs_blk_t blk_start, erofs_blk_t nblocks,
+					bool first_extent, bool last_extent);
 #else
 static inline void erofs_droid_blocklist_write(struct erofs_inode *inode,
 				 erofs_blk_t blk_start, erofs_blk_t nblocks) {}
 static inline void
 erofs_droid_blocklist_write_tail_end(struct erofs_inode *inode,
 					  erofs_blk_t blkaddr) {}
+static inline void
+erofs_droid_blocklist_write_extent(struct erofs_inode *inode,
+				   erofs_blk_t blk_start, erofs_blk_t nblocks,
+				   bool first_extent, bool last_extent) {}
 #endif
 #endif
diff --git a/lib/blobchunk.c b/lib/blobchunk.c
index 661c5d0..a2e62be 100644
--- a/lib/blobchunk.c
+++ b/lib/blobchunk.c
@@ -7,6 +7,7 @@
 #define _GNU_SOURCE
 #include "erofs/hashmap.h"
 #include "erofs/blobchunk.h"
+#include "erofs/block_list.h"
 #include "erofs/cache.h"
 #include "erofs/io.h"
 #include <unistd.h>
@@ -101,7 +102,10 @@ int erofs_blob_write_chunk_indexes(struct erofs_inode *inode,
 				   erofs_off_t off)
 {
 	struct erofs_inode_chunk_index idx = {0};
-	unsigned int dst, src, unit;
+	erofs_blk_t extent_start = EROFS_NULL_ADDR;
+	erofs_blk_t extent_end = EROFS_NULL_ADDR;
+	unsigned int dst, src, unit, num_extents;
+	bool first_extent = true;
 
 	if (inode->u.chunkformat & EROFS_CHUNK_FORMAT_INDEXES)
 		unit = sizeof(struct erofs_inode_chunk_index);
@@ -115,6 +119,20 @@ int erofs_blob_write_chunk_indexes(struct erofs_inode *inode,
 		chunk = *(void **)(inode->chunkindexes + src);
 
 		idx.blkaddr = chunk->blkaddr + remapped_base;
+		if (extent_start != EROFS_NULL_ADDR &&
+		    idx.blkaddr == extent_end + 1) {
+			extent_end = idx.blkaddr;
+		} else {
+			if (extent_start != EROFS_NULL_ADDR) {
+				erofs_droid_blocklist_write_extent(inode,
+					extent_start,
+					(extent_end - extent_start) + 1,
+					first_extent, false);
+				first_extent = false;
+			}
+			extent_start = idx.blkaddr;
+			extent_end = idx.blkaddr;
+		}
 		if (unit == EROFS_BLOCK_MAP_ENTRY_SIZE)
 			memcpy(inode->chunkindexes + dst, &idx.blkaddr, unit);
 		else
@@ -122,6 +140,13 @@ int erofs_blob_write_chunk_indexes(struct erofs_inode *inode,
 	}
 	off = roundup(off, unit);
 
+	if (extent_start == EROFS_NULL_ADDR)
+		num_extents = 0;
+	else
+		num_extents = (extent_end - extent_start) + 1;
+	erofs_droid_blocklist_write_extent(inode, extent_start, num_extents,
+		first_extent, true);
+
 	return dev_write(inode->chunkindexes, off, inode->extent_isize);
 }
 
diff --git a/lib/block_list.c b/lib/block_list.c
index 096dc9b..87609a9 100644
--- a/lib/block_list.c
+++ b/lib/block_list.c
@@ -32,25 +32,48 @@ void erofs_droid_blocklist_fclose(void)
 }
 
 static void blocklist_write(const char *path, erofs_blk_t blk_start,
-			    erofs_blk_t nblocks, bool has_tail)
+			    erofs_blk_t nblocks, bool first_extent,
+			    bool last_extent)
 {
 	const char *fspath = erofs_fspath(path);
 
-	fprintf(block_list_fp, "/%s", cfg.mount_point);
+	if (first_extent) {
+		fprintf(block_list_fp, "/%s", cfg.mount_point);
 
-	if (fspath[0] != '/')
-		fprintf(block_list_fp, "/");
+		if (fspath[0] != '/')
+			fprintf(block_list_fp, "/");
+
+		fprintf(block_list_fp, "%s", fspath);
+	}
 
 	if (nblocks == 1)
-		fprintf(block_list_fp, "%s %u", fspath, blk_start);
+		fprintf(block_list_fp, " %u", blk_start);
 	else
-		fprintf(block_list_fp, "%s %u-%u", fspath, blk_start,
+		fprintf(block_list_fp, " %u-%u", blk_start,
 			blk_start + nblocks - 1);
 
-	if (!has_tail)
+	if (last_extent)
 		fprintf(block_list_fp, "\n");
 }
 
+void erofs_droid_blocklist_write_extent(struct erofs_inode *inode,
+					erofs_blk_t blk_start,
+					erofs_blk_t nblocks, bool first_extent,
+					bool last_extent)
+{
+	if (!block_list_fp || !cfg.mount_point)
+		return;
+
+	if (!nblocks) {
+		if (last_extent)
+			fprintf(block_list_fp, "\n");
+		return;
+	}
+
+	blocklist_write(inode->i_srcpath, blk_start, nblocks, first_extent,
+			last_extent);
+}
+
 void erofs_droid_blocklist_write(struct erofs_inode *inode,
 				 erofs_blk_t blk_start, erofs_blk_t nblocks)
 {
@@ -58,7 +81,7 @@ void erofs_droid_blocklist_write(struct erofs_inode *inode,
 		return;
 
 	blocklist_write(inode->i_srcpath, blk_start, nblocks,
-			!!inode->idata_size);
+			true, !inode->idata_size);
 }
 
 void erofs_droid_blocklist_write_tail_end(struct erofs_inode *inode,
@@ -80,6 +103,6 @@ void erofs_droid_blocklist_write_tail_end(struct erofs_inode *inode,
 		return;
 	}
 	if (blkaddr != NULL_ADDR)
-		blocklist_write(inode->i_srcpath, blkaddr, 1, false);
+		blocklist_write(inode->i_srcpath, blkaddr, 1, true, true);
 }
 #endif
-- 
2.34.0.rc0.344.g81b53c2807-goog