From 8ee3ee9c71418dbdb73d4350c17056024fb7ec41 Mon Sep 17 00:00:00 2001
From: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Date: Sun, 15 Sep 2019 17:56:07 +0200
Subject: Replace file descriptor IO in data_writer with sqfs_file_t

First, this commit moves the create-blocks-from-fd function over to
libsquashfs and ports it to work on an sqfs_file_t instead.

Second, the function in the data_writer that reads from a file descriptor
is adjusted to use an sqfs_file_t instead.

Finally, the tools that use it have to be adjusted accordingly.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
---
 lib/sqfs/io.c | 146 +++++++---------------------------------------------------
 1 file changed, 17 insertions(+), 129 deletions(-)

(limited to 'lib/sqfs/io.c')

diff --git a/lib/sqfs/io.c b/lib/sqfs/io.c
index f8773d0..4afb489 100644
--- a/lib/sqfs/io.c
+++ b/lib/sqfs/io.c
@@ -9,143 +9,31 @@
 
 #include "sqfs/io.h"
 #include "sqfs/error.h"
+#include "sqfs/block_processor.h"
+#include "util.h"
 
 #include <stdlib.h>
-#include <unistd.h>
-#include <errno.h>
-#include <fcntl.h>
 
-
-typedef struct {
-	sqfs_file_t base;
-
-	uint64_t size;
-	int fd;
-} sqfs_file_stdio_t;
-
-
-static void stdio_destroy(sqfs_file_t *base)
-{
-	sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
-
-	close(file->fd);
-	free(file);
-}
-
-static int stdio_read_at(sqfs_file_t *base, uint64_t offset,
-			 void *buffer, size_t size)
-{
-	sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
-	ssize_t ret;
-
-	while (size > 0) {
-		ret = pread(file->fd, buffer, size, offset);
-
-		if (ret < 0) {
-			if (errno == EINTR)
-				continue;
-			return SQFS_ERROR_IO;
-		}
-
-		if (ret == 0)
-			return SQFS_ERROR_OUT_OF_BOUNDS;
-
-		buffer = (char *)buffer + ret;
-		size -= ret;
-		offset += ret;
-	}
-
-	return 0;
-}
-
-static int stdio_write_at(sqfs_file_t *base, uint64_t offset,
-			  const void *buffer, size_t size)
+int sqfs_file_create_block(sqfs_file_t *file, uint64_t offset,
+			   size_t size, void *user, uint32_t flags,
+			   sqfs_block_t **out)
 {
-	sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
-	ssize_t ret;
-
-	while (size > 0) {
-		ret = pwrite(file->fd, buffer, size, offset);
-
-		if (ret < 0) {
-			if (errno == EINTR)
-				continue;
-			return SQFS_ERROR_IO;
-		}
+	sqfs_block_t *blk = alloc_flex(sizeof(*blk), 1, size);
+	int err;
 
-		if (ret == 0)
-			return SQFS_ERROR_OUT_OF_BOUNDS;
+	if (blk == NULL)
+		return SQFS_ERROR_ALLOC;
 
-		buffer = (const char *)buffer + ret;
-		size -= ret;
-		offset += ret;
+	err = file->read_at(file, offset, blk->data, size);
+	if (err) {
+		free(blk);
+		return err;
 	}
 
-	if (offset >= file->size)
-		file->size = offset;
+	blk->user = user;
+	blk->size = size;
+	blk->flags = flags;
 
+	*out = blk;
 	return 0;
 }
-
-static uint64_t stdio_get_size(const sqfs_file_t *base)
-{
-	const sqfs_file_stdio_t *file = (const sqfs_file_stdio_t *)base;
-
-	return file->size;
-}
-
-static int stdio_truncate(sqfs_file_t *base, uint64_t size)
-{
-	sqfs_file_stdio_t *file = (sqfs_file_stdio_t *)base;
-
-	if (ftruncate(file->fd, size))
-		return SQFS_ERROR_IO;
-
-	file->size = size;
-	return 0;
-}
-
-
-sqfs_file_t *sqfs_open_file(const char *filename, int flags)
-{
-	sqfs_file_stdio_t *file;
-	int open_mode, temp;
-	sqfs_file_t *base;
-
-	if (flags & ~SQFS_FILE_OPEN_ALL_FLAGS) {
-		errno = EINVAL;
-		return NULL;
-	}
-
-	file = calloc(1, sizeof(*file));
-	base = (sqfs_file_t *)file;
-	if (file == NULL)
-		return NULL;
-
-	if (flags & SQFS_FILE_OPEN_READ_ONLY) {
-		open_mode = O_RDONLY;
-	} else {
-		open_mode = O_CREAT | O_RDWR;
-
-		if (flags & SQFS_FILE_OPEN_OVERWRITE) {
-			open_mode |= O_TRUNC;
-		} else {
-			open_mode |= O_EXCL;
-		}
-	}
-
-	file->fd = open(filename, open_mode, 0600);
-	if (file->fd < 0) {
-		temp = errno;
-		free(file);
-		errno = temp;
-		return NULL;
-	}
-
-	base->destroy = stdio_destroy;
-	base->read_at = stdio_read_at;
-	base->write_at = stdio_write_at;
-	base->get_size = stdio_get_size;
-	base->truncate = stdio_truncate;
-	return base;
-}
-- 
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