Replace direct file I/O with abstraction layer

This should make it easier to use libsquashfs with custom setups that
embedd a squashfs image inside something else. Also, it should make
it easier to port to non unix-like platforms.

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

3 files changed, 23 insertions, 21 deletions

diff --git a/mkfs/mkfs.c b/mkfs/mkfs.c
index 540dbea..05e8481 100644
--- a/mkfs/mkfs.c
+++ b/mkfs/mkfs.c
@@ -96,11 +96,11 @@ int main(int argc, char **argv)
 	sqfs_compressor_config_t cfg;
 	sqfs_compressor_t *cmp;
 	sqfs_id_table_t *idtbl;
+	sqfs_file_t *outfile;
 	data_writer_t *data;
 	sqfs_super_t super;
 	options_t opt;
 	fstree_t fs;
-	int outfd;
 
 	process_command_line(&opt, argc, argv);
 
@@ -121,22 +121,22 @@ int main(int argc, char **argv)
 	if (idtbl == NULL)
 		goto out_fstree;
 
-	outfd = open(opt.outfile, opt.outmode, 0644);
-	if (outfd < 0) {
+	outfile = sqfs_open_file(opt.outfile, opt.outmode);
+	if (outfile == NULL) {
 		perror(opt.outfile);
 		goto out_idtbl;
 	}
 
-	if (sqfs_super_write(&super, outfd))
-		goto out_outfd;
+	if (sqfs_super_write(&super, outfile))
+		goto out_outfile;
 
 	if (read_fstree(&fs, &opt))
-		goto out_outfd;
+		goto out_outfile;
 
 	tree_node_sort_recursive(fs.root);
 
 	if (fstree_gen_inode_table(&fs))
-		goto out_outfd;
+		goto out_outfile;
 
 	fstree_gen_file_list(&fs);
 
@@ -145,7 +145,7 @@ int main(int argc, char **argv)
 #ifdef WITH_SELINUX
 	if (opt.selinux != NULL) {
 		if (fstree_relabel_selinux(&fs, opt.selinux))
-			goto out_outfd;
+			goto out_outfile;
 	}
 #endif
 
@@ -154,10 +154,10 @@ int main(int argc, char **argv)
 	cmp = sqfs_compressor_create(&cfg);
 	if (cmp == NULL) {
 		fputs("Error creating compressor\n", stderr);
-		goto out_outfd;
+		goto out_outfile;
 	}
 
-	ret = cmp->write_options(cmp, outfd);
+	ret = cmp->write_options(cmp, outfile);
 	if (ret < 0)
 		goto out_cmp;
 
@@ -166,7 +166,7 @@ int main(int argc, char **argv)
 		super.bytes_used += ret;
 	}
 
-	data = data_writer_create(&super, cmp, outfd,
+	data = data_writer_create(&super, cmp, outfile,
 				  opt.devblksz, opt.num_jobs);
 	if (data == NULL)
 		goto out_cmp;
@@ -174,27 +174,27 @@ int main(int argc, char **argv)
 	if (pack_files(data, &fs, &opt))
 		goto out_data;
 
-	if (sqfs_serialize_fstree(outfd, &super, &fs, cmp, idtbl))
+	if (sqfs_serialize_fstree(outfile, &super, &fs, cmp, idtbl))
 		goto out_data;
 
 	if (data_writer_write_fragment_table(data))
 		goto out_data;
 
 	if (opt.exportable) {
-		if (write_export_table(outfd, &fs, &super, cmp))
+		if (write_export_table(outfile, &fs, &super, cmp))
 			goto out_data;
 	}
 
-	if (sqfs_id_table_write(idtbl, outfd, &super, cmp))
+	if (sqfs_id_table_write(idtbl, outfile, &super, cmp))
 		goto out_data;
 
-	if (write_xattr(outfd, &fs, &super, cmp))
+	if (write_xattr(outfile, &fs, &super, cmp))
 		goto out_data;
 
-	if (sqfs_super_write(&super, outfd))
+	if (sqfs_super_write(&super, outfile))
 		goto out_data;
 
-	if (padd_file(outfd, super.bytes_used, opt.devblksz))
+	if (padd_sqfs(outfile, super.bytes_used, opt.devblksz))
 		goto out_data;
 
 	if (!opt.quiet) {
@@ -207,8 +207,8 @@ out_data:
 	data_writer_destroy(data);
 out_cmp:
 	cmp->destroy(cmp);
-out_outfd:
-	close(outfd);
+out_outfile:
+	outfile->destroy(outfile);
 out_idtbl:
 	sqfs_id_table_destroy(idtbl);
 out_fstree:
diff --git a/mkfs/mkfs.h b/mkfs/mkfs.h
index 24f8e9c..7ad9460 100644
--- a/mkfs/mkfs.h
+++ b/mkfs/mkfs.h
@@ -13,6 +13,8 @@
 #include "sqfs/compress.h"
 #include "sqfs/id_table.h"
 #include "sqfs/data.h"
+#include "sqfs/io.h"
+
 #include "data_writer.h"
 #include "highlevel.h"
 #include "fstree.h"
diff --git a/mkfs/options.c b/mkfs/options.c
index 9e747d8..7b83ec4 100644
--- a/mkfs/options.c
+++ b/mkfs/options.c
@@ -146,7 +146,7 @@ void process_command_line(options_t *opt, int argc, char **argv)
 	int i;
 
 	memset(opt, 0, sizeof(*opt));
-	opt->outmode = O_WRONLY | O_CREAT | O_EXCL;
+	opt->outmode = 0;
 	opt->compressor = compressor_get_default();
 	opt->blksz = SQFS_DEFAULT_BLOCK_SIZE;
 	opt->devblksz = SQFS_DEVBLK_SIZE;
@@ -207,7 +207,7 @@ void process_command_line(options_t *opt, int argc, char **argv)
 			opt->exportable = true;
 			break;
 		case 'f':
-			opt->outmode = O_WRONLY | O_CREAT | O_TRUNC;
+			opt->outmode |= SQFS_FILE_OPEN_OVERWRITE;
 			break;
 		case 'q':
 			opt->quiet = true;