[PATCH V4 05/11] misc/create_inode.c: copy regular file

[Robert Yang <liezhi.yang@windriver.com>]

The do_write_internal() is used for copying file from native fs to
target, most of the code are from debugfs/debugfs.c, the
debugfs/debugfs.c will be modified to use this function.

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Reviewed-by: Darren Hart <dvhart@linux.intel.com>
---
 misc/create_inode.c |  183 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 183 insertions(+)

diff --git a/misc/create_inode.c b/misc/create_inode.c
index f845103..98f4a93 100644
--- a/misc/create_inode.c
+++ b/misc/create_inode.c
@@ -8,6 +8,16 @@
 # endif
 #endif
 
+/* 64KiB is the minimium blksize to best minimize system call overhead. */
+#ifndef IO_BUFSIZE
+#define IO_BUFSIZE 64*1024
+#endif
+
+/* Block size for `st_blocks' */
+#ifndef S_BLKSIZE
+#define S_BLKSIZE 512
+#endif
+
 /* Make a special file which is block, character and fifo */
 errcode_t do_mknod_internal(ext2_ino_t cwd, const char *name, struct stat *st)
 {
@@ -127,9 +137,182 @@ errcode_t do_mkdir_internal(ext2_ino_t cwd, const char *name, struct stat *st)
 {
 }
 
+static errcode_t copy_file(int fd, ext2_ino_t newfile, int bufsize, int make_holes)
+{
+	ext2_file_t	e2_file;
+	errcode_t	retval;
+	int		got;
+	unsigned int	written;
+	char		*buf;
+	char		*ptr;
+	char		*zero_buf;
+	int		cmp;
+
+	retval = ext2fs_file_open(current_fs, newfile,
+				  EXT2_FILE_WRITE, &e2_file);
+	if (retval)
+		return retval;
+
+	retval = ext2fs_get_mem(bufsize, &buf);
+	if (retval) {
+		com_err("copy_file", retval, "can't allocate buffer\n");
+		return retval;
+	}
+
+	/* This is used for checking whether the whole block is zero */
+	retval = ext2fs_get_memzero(bufsize, &zero_buf);
+	if (retval) {
+		com_err("copy_file", retval, "can't allocate buffer\n");
+		ext2fs_free_mem(&buf);
+		return retval;
+	}
+
+	while (1) {
+		got = read(fd, buf, bufsize);
+		if (got == 0)
+			break;
+		if (got < 0) {
+			retval = errno;
+			goto fail;
+		}
+		ptr = buf;
+
+		/* Sparse copy */
+		if (make_holes) {
+			/* Check whether all is zero */
+			cmp = memcmp(ptr, zero_buf, got);
+			if (cmp == 0) {
+				 /* The whole block is zero, make a hole */
+				retval = ext2fs_file_lseek(e2_file, got, EXT2_SEEK_CUR, NULL);
+				if (retval)
+					goto fail;
+				got = 0;
+			}
+		}
+
+		/* Normal copy */
+		while (got > 0) {
+			retval = ext2fs_file_write(e2_file, ptr,
+						   got, &written);
+			if (retval)
+				goto fail;
+
+			got -= written;
+			ptr += written;
+		}
+	}
+	ext2fs_free_mem(&buf);
+	ext2fs_free_mem(&zero_buf);
+	retval = ext2fs_file_close(e2_file);
+	return retval;
+
+fail:
+	ext2fs_free_mem(&buf);
+	ext2fs_free_mem(&zero_buf);
+	(void) ext2fs_file_close(e2_file);
+	return retval;
+}
+
 /* Copy the native file to the fs */
 errcode_t do_write_internal(ext2_ino_t cwd, const char *src, const char *dest)
 {
+	int		fd;
+	struct stat	statbuf;
+	ext2_ino_t	newfile;
+	errcode_t	retval;
+	struct ext2_inode inode;
+	int		bufsize = IO_BUFSIZE;
+	int		make_holes = 0;
+
+	fd = open(src, O_RDONLY);
+	if (fd < 0) {
+		com_err(src, errno, 0);
+		return errno;
+	}
+	if (fstat(fd, &statbuf) < 0) {
+		com_err(src, errno, 0);
+		close(fd);
+		return errno;
+	}
+
+	retval = ext2fs_namei(current_fs, root, cwd, dest, &newfile);
+	if (retval == 0) {
+		com_err(__func__, 0, "The file '%s' already exists\n", dest);
+		close(fd);
+		return errno;
+	}
+
+	retval = ext2fs_new_inode(current_fs, cwd, 010755, 0, &newfile);
+	if (retval) {
+		com_err(__func__, retval, 0);
+		close(fd);
+		return errno;
+	}
+#ifdef DEBUGFS
+	printf("Allocated inode: %u\n", newfile);
+#endif
+	retval = ext2fs_link(current_fs, cwd, dest, newfile,
+				EXT2_FT_REG_FILE);
+	if (retval == EXT2_ET_DIR_NO_SPACE) {
+		retval = ext2fs_expand_dir(current_fs, cwd);
+		if (retval) {
+			com_err(__func__, retval, "while expanding directory");
+			close(fd);
+			return errno;
+		}
+		retval = ext2fs_link(current_fs, cwd, dest, newfile,
+					EXT2_FT_REG_FILE);
+	}
+	if (retval) {
+		com_err(dest, retval, 0);
+		close(fd);
+		return errno;
+	}
+        if (ext2fs_test_inode_bitmap2(current_fs->inode_map, newfile))
+		com_err(__func__, 0, "Warning: inode already set");
+	ext2fs_inode_alloc_stats2(current_fs, newfile, +1, 0);
+	memset(&inode, 0, sizeof(inode));
+	inode.i_mode = (statbuf.st_mode & ~LINUX_S_IFMT) | LINUX_S_IFREG;
+	inode.i_atime = inode.i_ctime = inode.i_mtime =
+		current_fs->now ? current_fs->now : time(0);
+	inode.i_links_count = 1;
+	inode.i_size = statbuf.st_size;
+	if (current_fs->super->s_feature_incompat &
+	    EXT3_FEATURE_INCOMPAT_EXTENTS) {
+		int i;
+		struct ext3_extent_header *eh;
+
+		eh = (struct ext3_extent_header *) &inode.i_block[0];
+		eh->eh_depth = 0;
+		eh->eh_entries = 0;
+		eh->eh_magic = ext2fs_cpu_to_le16(EXT3_EXT_MAGIC);
+		i = (sizeof(inode.i_block) - sizeof(*eh)) /
+			sizeof(struct ext3_extent);
+		eh->eh_max = ext2fs_cpu_to_le16(i);
+		inode.i_flags |= EXT4_EXTENTS_FL;
+	}
+
+	if ((retval = ext2fs_write_new_inode(current_fs, newfile, &inode))) {
+		com_err(__func__, retval, "while creating inode %u", newfile);
+		close(fd);
+		return errno;
+	}
+	if (LINUX_S_ISREG(inode.i_mode)) {
+		if (statbuf.st_blocks < statbuf.st_size / S_BLKSIZE) {
+			make_holes = 1;
+			/*
+			 * Use I/O blocksize as buffer size when
+			 * copying sparse files.
+			 */
+			bufsize = statbuf.st_blksize;
+		}
+		retval = copy_file(fd, newfile, bufsize, make_holes);
+		if (retval)
+			com_err("copy_file", retval, 0);
+	}
+	close(fd);
+
+	return 0;
 }
 
 /* Copy files from source_dir to fs */
-- 
1.7.10.4