block processor: move sparse block detection into worker thread

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

4 files changed, 71 insertions, 57 deletions

diff --git a/lib/sqfs/block_processor/common.c b/lib/sqfs/block_processor/common.c
index 002dad4..3859916 100644
--- a/lib/sqfs/block_processor/common.c
+++ b/lib/sqfs/block_processor/common.c
@@ -13,6 +13,11 @@ int process_completed_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
 	sqfs_u32 size;
 	int err;
 
+	err = sqfs_block_writer_write(proc->wr, blk->size, blk->checksum,
+				      blk->flags, blk->data, &location);
+	if (err)
+		return err;
+
 	if (blk->flags & SQFS_BLK_IS_SPARSE) {
 		sqfs_inode_make_extended(blk->inode);
 		blk->inode->data.file_ext.sparse += blk->size;
@@ -20,19 +25,11 @@ int process_completed_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
 		blk->inode->num_file_blocks += 1;
 
 		proc->stats.sparse_block_count += 1;
-		return 0;
-	}
-
-	size = blk->size;
-	if (!(blk->flags & SQFS_BLK_IS_COMPRESSED))
-		size |= 1 << 24;
-
-	err = sqfs_block_writer_write(proc->wr, blk->size, blk->checksum,
-				      blk->flags, blk->data, &location);
-	if (err)
-		return err;
+	} else if (blk->size != 0) {
+		size = blk->size;
+		if (!(blk->flags & SQFS_BLK_IS_COMPRESSED))
+			size |= 1 << 24;
 
-	if (blk->size != 0) {
 		if (blk->flags & SQFS_BLK_FRAGMENT_BLOCK) {
 			err = sqfs_frag_table_set(proc->frag_tbl, blk->index,
 						  location, size);
@@ -52,12 +49,23 @@ int process_completed_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
 	return 0;
 }
 
+static bool is_zero_block(unsigned char *ptr, size_t size)
+{
+	return ptr[0] == 0 && memcmp(ptr, ptr + 1, size - 1) == 0;
+}
+
 int block_processor_do_block(sqfs_block_t *block, sqfs_compressor_t *cmp,
 			     sqfs_u8 *scratch, size_t scratch_size)
 {
 	ssize_t ret;
 
-	if (block->size == 0 || (block->flags & SQFS_BLK_IS_SPARSE)) {
+	if (block->size == 0) {
+		block->checksum = 0;
+		return 0;
+	}
+
+	if (is_zero_block(block->data, block->size)) {
+		block->flags |= SQFS_BLK_IS_SPARSE;
 		block->checksum = 0;
 		return 0;
 	}
@@ -90,6 +98,16 @@ int process_completed_fragment(sqfs_block_processor_t *proc, sqfs_block_t *frag,
 	size_t size;
 	int err;
 
+	if (frag->flags & SQFS_BLK_IS_SPARSE) {
+		sqfs_inode_make_extended(frag->inode);
+		frag->inode->data.file_ext.sparse += frag->size;
+		frag->inode->extra[frag->inode->num_file_blocks] = 0;
+		frag->inode->num_file_blocks += 1;
+
+		proc->stats.sparse_block_count += 1;
+		return 0;
+	}
+
 	proc->stats.total_frag_count += 1;
 
 	err = sqfs_frag_table_find_tail_end(proc->frag_tbl,
diff --git a/lib/sqfs/block_processor/fileapi.c b/lib/sqfs/block_processor/fileapi.c
index 7ca189e..abaf3d2 100644
--- a/lib/sqfs/block_processor/fileapi.c
+++ b/lib/sqfs/block_processor/fileapi.c
@@ -7,11 +7,6 @@
 #define SQFS_BUILDING_DLL
 #include "internal.h"
 
-static bool is_zero_block(unsigned char *ptr, size_t size)
-{
-	return ptr[0] == 0 && memcmp(ptr, ptr + 1, size - 1) == 0;
-}
-
 static int enqueue_block(sqfs_block_processor_t *proc, sqfs_block_t *block)
 {
 	int status;
@@ -58,10 +53,8 @@ static int flush_block(sqfs_block_processor_t *proc, sqfs_block_t *block)
 	block->flags = proc->blk_flags;
 	block->inode = proc->inode;
 
-	if (is_zero_block(block->data, block->size)) {
-		block->flags |= SQFS_BLK_IS_SPARSE;
-	} else if (block->size < proc->max_block_size &&
-		   !(block->flags & SQFS_BLK_DONT_FRAGMENT)) {
+	if (block->size < proc->max_block_size &&
+	    !(block->flags & SQFS_BLK_DONT_FRAGMENT)) {
 		block->flags |= SQFS_BLK_IS_FRAGMENT;
 	} else {
 		proc->blk_flags &= ~SQFS_BLK_FIRST_BLOCK;
diff --git a/lib/sqfs/block_processor/serial.c b/lib/sqfs/block_processor/serial.c
index c9ee164..1d2c2db 100644
--- a/lib/sqfs/block_processor/serial.c
+++ b/lib/sqfs/block_processor/serial.c
@@ -43,35 +43,33 @@ int append_to_work_queue(sqfs_block_processor_t *proc, sqfs_block_t *block)
 {
 	sqfs_block_t *fragblk = NULL;
 
-	if (proc->status != 0 || block == NULL) {
-		free(block);
-		return proc->status;
-	}
+	if (proc->status != 0)
+		goto done;
 
-	if (block->flags & SQFS_BLK_IS_FRAGMENT) {
-		block->checksum = crc32(0, block->data, block->size);
+	proc->status = block_processor_do_block(block, proc->cmp,
+						proc->scratch,
+						proc->max_block_size);
+	if (proc->status != 0)
+		goto done;
 
+	if (block->flags & SQFS_BLK_IS_FRAGMENT) {
 		proc->status = process_completed_fragment(proc, block,
 							  &fragblk);
-		free(block);
-
-		if (proc->status != 0) {
-			free(fragblk);
-			return proc->status;
-		}
-
 		if (fragblk == NULL)
-			return 0;
+			goto done;
 
+		free(block);
 		block = fragblk;
-	}
-
-	proc->status = block_processor_do_block(block, proc->cmp, proc->scratch,
-						proc->max_block_size);
 
-	if (proc->status == 0)
-		proc->status = process_completed_block(proc, block);
+		proc->status = block_processor_do_block(block, proc->cmp,
+							proc->scratch,
+							proc->max_block_size);
+		if (proc->status != 0)
+			goto done;
+	}
 
+	proc->status = process_completed_block(proc, block);
+done:
 	free(block);
 	return proc->status;
 }
diff --git a/lib/sqfs/block_writer.c b/lib/sqfs/block_writer.c
index 63f8c61..73dcb14 100644
--- a/lib/sqfs/block_writer.c
+++ b/lib/sqfs/block_writer.c
@@ -191,14 +191,14 @@ int sqfs_block_writer_write(sqfs_block_writer_t *wr, sqfs_u32 size,
 		}
 	}
 
-	if (size != 0) {
+	offset = wr->file->get_size(wr->file);
+	*location = offset;
+
+	if (size != 0 && !(flags & SQFS_BLK_IS_SPARSE)) {
 		out = size;
 		if (!(flags & SQFS_BLK_IS_COMPRESSED))
 			out |= 1 << 24;
 
-		offset = wr->file->get_size(wr->file);
-		*location = offset;
-
 		err = store_block_location(wr, offset, out, checksum);
 		if (err)
 			return err;
@@ -226,19 +226,24 @@ int sqfs_block_writer_write(sqfs_block_writer_t *wr, sqfs_u32 size,
 		}
 
 		count = wr->num_blocks - wr->file_start;
-		start = deduplicate_blocks(wr, count);
-		offset = wr->blocks[start].offset;
-
-		*location = offset;
-		if (start >= wr->file_start)
-			return 0;
 
-		offset = start + count;
-		if (offset >= wr->file_start) {
-			count = wr->num_blocks - offset;
-			wr->num_blocks = offset;
+		if (count == 0) {
+			*location = 0;
 		} else {
-			wr->num_blocks = wr->file_start;
+			start = deduplicate_blocks(wr, count);
+			offset = wr->blocks[start].offset;
+
+			*location = offset;
+			if (start >= wr->file_start)
+				return 0;
+
+			offset = start + count;
+			if (offset >= wr->file_start) {
+				count = wr->num_blocks - offset;
+				wr->num_blocks = offset;
+			} else {
+				wr->num_blocks = wr->file_start;
+			}
 		}
 
 		err = wr->file->truncate(wr->file, wr->start);