Overhaul sqfs_istream_t/sqfs_ostream_t error handling

Report an error number from the implementations, change the users to
forward that error number (which also means libtar write header/link
now returns an error code) and all subsequent binaries to use
sqfs_perror() instead of relying on the function to print an error
internally.

Also, make sure to preserve errno/GetLastError() in the implementations
and print out a stringified error in sqfs_perror() if the error code
indicates an I/O error.

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

1 files changed, 8 insertions, 6 deletions

diff --git a/lib/common/src/data_reader_dump.c b/lib/common/src/data_reader_dump.c
index e3cbb87..920b2bd 100644
--- a/lib/common/src/data_reader_dump.c
+++ b/lib/common/src/data_reader_dump.c
@@ -26,8 +26,7 @@ int sqfs_data_reader_dump(const char *name, sqfs_data_reader_t *data,
 		diff = (filesz < block_size) ? filesz : block_size;
 
 		if (SQFS_IS_SPARSE_BLOCK(inode->extra[i])) {
-			if (fp->append(fp, NULL, diff))
-				return -1;
+			err = fp->append(fp, NULL, diff);
 		} else {
 			err = sqfs_data_reader_get_block(data, inode, i,
 							 &chunk_size, &chunk);
@@ -38,11 +37,11 @@ int sqfs_data_reader_dump(const char *name, sqfs_data_reader_t *data,
 
 			err = fp->append(fp, chunk, chunk_size);
 			free(chunk);
-
-			if (err)
-				return -1;
 		}
 
+		if (err)
+			goto fail_io;
+
 		filesz -= diff;
 	}
 
@@ -58,8 +57,11 @@ int sqfs_data_reader_dump(const char *name, sqfs_data_reader_t *data,
 		free(chunk);
 
 		if (err)
-			return -1;
+			goto fail_io;
 	}
 
 	return 0;
+fail_io:
+	sqfs_perror(fp->get_filename(fp), "writing data block", err);
+	return -1;
 }