Remove raw file descriptors from unpack write paths

Instead, use stdio FILE pointers. On POSIX systems, use fileno to get
the file descriptor and hopefully create sparase files.

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

4 files changed, 52 insertions, 54 deletions

diff --git a/lib/common/data_reader_dump.c b/lib/common/data_reader_dump.c
index 4053f73..4065677 100644
--- a/lib/common/data_reader_dump.c
+++ b/lib/common/data_reader_dump.c
@@ -12,26 +12,23 @@
 #include <stdio.h>
 #include <errno.h>
 
-static int append_block(int fd, const sqfs_block_t *blk)
+static int append_block(FILE *fp, const sqfs_block_t *blk)
 {
 	const unsigned char *ptr = blk->data;
-	size_t size = blk->size;
-	ssize_t ret;
+	size_t ret, size = blk->size;
 
 	while (size > 0) {
-		ret = write(fd, ptr, size);
-
-		if (ret < 0) {
-			if (errno == EINTR)
-				continue;
-			perror("writing data block");
+		if (ferror(fp)) {
+			fputs("writing data block: error writing to file\n",
+			      stderr);
 		}
 
-		if (ret == 0) {
+		if (feof(fp)) {
 			fputs("writing data block: unexpected end of file\n",
 			      stderr);
 		}
 
+		ret = fwrite(ptr, 1, size, fp);
 		ptr += ret;
 		size -= ret;
 	}
@@ -41,7 +38,7 @@ static int append_block(int fd, const sqfs_block_t *blk)
 
 int sqfs_data_reader_dump(const char *name, sqfs_data_reader_t *data,
 			  const sqfs_inode_generic_t *inode,
-			  int outfd, size_t block_size, bool allow_sparse)
+			  FILE *fp, size_t block_size, bool allow_sparse)
 {
 	sqfs_block_t *blk;
 	sqfs_u64 filesz;
@@ -50,21 +47,23 @@ int sqfs_data_reader_dump(const char *name, sqfs_data_reader_t *data,
 
 	sqfs_inode_get_file_size(inode, &filesz);
 
-	if (allow_sparse && ftruncate(outfd, filesz))
-		goto fail_sparse;
+#if defined(_POSIX_VERSION) && (_POSIX_VERSION >= 200112L)
+	if (allow_sparse) {
+		int fd = fileno(fp);
+
+		if (ftruncate(fd, filesz))
+			goto fail_sparse;
+	}
+#else
+	allow_sparse = false;
+#endif
 
 	for (i = 0; i < inode->num_file_blocks; ++i) {
+		diff = (filesz < block_size) ? filesz : block_size;
+
 		if (SQFS_IS_SPARSE_BLOCK(inode->block_sizes[i]) &&
 		    allow_sparse) {
-			if (filesz < block_size) {
-				diff = filesz;
-				filesz = 0;
-			} else {
-				diff = block_size;
-				filesz -= block_size;
-			}
-
-			if (lseek(outfd, diff, SEEK_CUR) == (off_t)-1)
+			if (fseek(fp, diff, SEEK_CUR) < 0)
 				goto fail_sparse;
 		} else {
 			err = sqfs_data_reader_get_block(data, inode, i, &blk);
@@ -73,14 +72,14 @@ int sqfs_data_reader_dump(const char *name, sqfs_data_reader_t *data,
 				return -1;
 			}
 
-			if (append_block(outfd, blk)) {
-				free(blk);
-				return -1;
-			}
-
-			filesz -= blk->size;
+			err = append_block(fp, blk);
 			free(blk);
+
+			if (err)
+				return -1;
 		}
+
+		filesz -= diff;
 	}
 
 	if (filesz > 0) {
@@ -90,7 +89,7 @@ int sqfs_data_reader_dump(const char *name, sqfs_data_reader_t *data,
 			return -1;
 		}
 
-		if (append_block(outfd, blk)) {
+		if (append_block(fp, blk)) {
 			free(blk);
 			return -1;
 		}
diff --git a/lib/tar/padd_file.c b/lib/tar/padd_file.c
index f58cfbf..dd945a3 100644
--- a/lib/tar/padd_file.c
+++ b/lib/tar/padd_file.c
@@ -10,7 +10,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 
-int padd_file(int outfd, sqfs_u64 size)
+int padd_file(FILE *fp, sqfs_u64 size)
 {
 	size_t padd_sz = size % TAR_RECORD_SIZE;
 	int status = -1;
@@ -26,7 +26,7 @@ int padd_file(int outfd, sqfs_u64 size)
 		goto fail_errno;
 
 	if (write_retry("padding output file to block size",
-			outfd, buffer, padd_sz)) {
+			fp, buffer, padd_sz)) {
 		goto out;
 	}
 
diff --git a/lib/tar/write_header.c b/lib/tar/write_header.c
index 84aa2d3..6626d00 100644
--- a/lib/tar/write_header.c
+++ b/lib/tar/write_header.c
@@ -53,7 +53,7 @@ static void write_number_signed(char *dst, sqfs_s64 value, int digits)
 	}
 }
 
-static int write_header(int fd, const struct stat *sb, const char *name,
+static int write_header(FILE *fp, const struct stat *sb, const char *name,
 			const char *slink_target, int type)
 {
 	int maj = 0, min = 0;
@@ -88,10 +88,10 @@ static int write_header(int fd, const struct stat *sb, const char *name,
 
 	update_checksum(&hdr);
 
-	return write_retry("writing tar header record", fd, &hdr, sizeof(hdr));
+	return write_retry("writing tar header record", fp, &hdr, sizeof(hdr));
 }
 
-static int write_gnu_header(int fd, const struct stat *orig,
+static int write_gnu_header(FILE *fp, const struct stat *orig,
 			    const char *payload, size_t payload_len,
 			    int type, const char *name)
 {
@@ -101,15 +101,15 @@ static int write_gnu_header(int fd, const struct stat *orig,
 	sb.st_mode = S_IFREG | 0644;
 	sb.st_size = payload_len;
 
-	if (write_header(fd, &sb, name, NULL, type))
+	if (write_header(fp, &sb, name, NULL, type))
 		return -1;
 
 	if (write_retry("writing GNU extension header",
-			fd, payload, payload_len)) {
+			fp, payload, payload_len)) {
 		return -1;
 	}
 
-	return padd_file(fd, payload_len);
+	return padd_file(fp, payload_len);
 }
 
 static size_t num_digits(size_t num)
@@ -124,7 +124,7 @@ static size_t num_digits(size_t num)
 	return i;
 }
 
-static int write_schily_xattr(int fd, const struct stat *orig,
+static int write_schily_xattr(FILE *fp, const struct stat *orig,
 			      const char *name, const tar_xattr_t *xattr)
 {
 	static const char *prefix = "SCHILY.xattr.";
@@ -142,20 +142,20 @@ static int write_schily_xattr(int fd, const struct stat *orig,
 	sb.st_mode = S_IFREG | 0644;
 	sb.st_size = total_size;
 
-	if (write_header(fd, &sb, name, NULL, TAR_TYPE_PAX))
+	if (write_header(fp, &sb, name, NULL, TAR_TYPE_PAX))
 		return -1;
 
 	for (it = xattr; it != NULL; it = it->next) {
 		len = strlen(prefix) + strlen(it->key) + strlen(it->value) + 2;
 		len += num_digits(len) + 1;
 
-		dprintf(fd, "%zu %s%s=%s\n", len, prefix, it->key, it->value);
+		fprintf(fp, "%zu %s%s=%s\n", len, prefix, it->key, it->value);
 	}
 
-	return padd_file(fd, total_size);
+	return padd_file(fp, total_size);
 }
 
-int write_tar_header(int fd, const struct stat *sb, const char *name,
+int write_tar_header(FILE *fp, const struct stat *sb, const char *name,
 		     const char *slink_target, const tar_xattr_t *xattr,
 		     unsigned int counter)
 {
@@ -166,7 +166,7 @@ int write_tar_header(int fd, const struct stat *sb, const char *name,
 	if (xattr != NULL) {
 		sprintf(buffer, "pax/xattr%u", counter);
 
-		if (write_schily_xattr(fd, sb, buffer, xattr))
+		if (write_schily_xattr(fp, sb, buffer, xattr))
 			return -1;
 	}
 
@@ -175,7 +175,7 @@ int write_tar_header(int fd, const struct stat *sb, const char *name,
 
 	if (S_ISLNK(sb->st_mode) && sb->st_size >= 100) {
 		sprintf(buffer, "gnu/target%u", counter);
-		if (write_gnu_header(fd, sb, slink_target, sb->st_size,
+		if (write_gnu_header(fp, sb, slink_target, sb->st_size,
 				     TAR_TYPE_GNU_SLINK, buffer))
 			return -1;
 		slink_target = NULL;
@@ -184,7 +184,7 @@ int write_tar_header(int fd, const struct stat *sb, const char *name,
 	if (strlen(name) >= 100) {
 		sprintf(buffer, "gnu/name%u", counter);
 
-		if (write_gnu_header(fd, sb, name, strlen(name),
+		if (write_gnu_header(fp, sb, name, strlen(name),
 				     TAR_TYPE_GNU_PATH, buffer)) {
 			return -1;
 		}
@@ -208,7 +208,7 @@ int write_tar_header(int fd, const struct stat *sb, const char *name,
 		goto out_skip;
 	}
 
-	return write_header(fd, sb, name, slink_target, type);
+	return write_header(fp, sb, name, slink_target, type);
 out_skip:
 	fprintf(stderr, "WARNING: %s: %s\n", name, reason);
 	return 1;
diff --git a/lib/tar/write_retry.c b/lib/tar/write_retry.c
index 1ff1a7e..3977db1 100644
--- a/lib/tar/write_retry.c
+++ b/lib/tar/write_retry.c
@@ -12,23 +12,22 @@
 
 #include "tar.h"
 
-int write_retry(const char *errstr, int fd, const void *data, size_t size)
+int write_retry(const char *errstr, FILE *fp, const void *data, size_t size)
 {
-	ssize_t ret;
+	size_t ret;
 
 	while (size > 0) {
-		ret = write(fd, data, size);
-		if (ret == 0) {
+		if (feof(fp)) {
 			fprintf(stderr, "%s: write truncated\n", errstr);
 			return -1;
 		}
-		if (ret < 0) {
-			if (errno == EINTR)
-				continue;
-			perror(errstr);
+
+		if (ferror(fp)) {
+			fprintf(stderr, "%s: error writing to file\n", errstr);
 			return -1;
 		}
 
+		ret = fwrite(data, 1, size, fp);
 		data = (const char *)data + ret;
 		size -= ret;
 	}