1 files changed, 150 insertions, 0 deletions
diff --git a/lib/ext2fs/symlink.c b/lib/ext2fs/symlink.c
new file mode 100644
index 00000000..b2ef66c2
--- /dev/null
+++ b/lib/ext2fs/symlink.c
@@ -0,0 +1,150 @@
+/*
+ * symlink.c --- make a symlink in the filesystem, based on mkdir.c
+ *
+ * Copyright (c) 2012, Intel Corporation.
+ * All Rights Reserved.
+ *
+ * %Begin-Header%
+ * This file may be redistributed under the terms of the GNU Library
+ * General Public License, version 2.
+ * %End-Header%
+ */
+
+#include "config.h"
+#include <stdio.h>
+#include <string.h>
+#if HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+#include <fcntl.h>
+#include <time.h>
+#if HAVE_SYS_STAT_H
+#include <sys/stat.h>
+#endif
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+
+#include "ext2_fs.h"
+#include "ext2fs.h"
+
+errcode_t ext2fs_symlink(ext2_filsys fs, ext2_ino_t parent, ext2_ino_t ino,
+			 const char *name, char *target)
+{
+	errcode_t		retval;
+	struct ext2_inode	inode;
+	ext2_ino_t		scratch_ino;
+	blk64_t			blk;
+	int			fastlink;
+	unsigned int		target_len;
+	char			*block_buf = 0;
+
+	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
+
+	/* The Linux kernel doesn't allow for links longer than a block */
+	target_len = strlen(target);
+	if (target_len > fs->blocksize) {
+		retval = EXT2_ET_INVALID_ARGUMENT;
+		goto cleanup;
+	}
+
+	/*
+	 * Allocate a data block for slow links
+	 */
+	fastlink = (target_len < sizeof(inode.i_block));
+	if (!fastlink) {
+		retval = ext2fs_new_block2(fs, 0, 0, &blk);
+		if (retval)
+			goto cleanup;
+		retval = ext2fs_get_mem(fs->blocksize, &block_buf);
+		if (retval)
+			goto cleanup;
+	}
+
+	/*
+	 * Allocate an inode, if necessary
+	 */
+	if (!ino) {
+		retval = ext2fs_new_inode(fs, parent, LINUX_S_IFLNK | 0755,
+					  0, &ino);
+		if (retval)
+			goto cleanup;
+	}
+
+	/*
+	 * Create the inode structure....
+	 */
+	memset(&inode, 0, sizeof(struct ext2_inode));
+	inode.i_mode = LINUX_S_IFLNK | 0777;
+	inode.i_uid = inode.i_gid = 0;
+	ext2fs_iblk_set(fs, &inode, fastlink ? 0 : 1);
+	inode.i_links_count = 1;
+	inode.i_size = target_len;
+	/* The time fields are set by ext2fs_write_new_inode() */
+
+	if (fastlink) {
+		/* Fast symlinks, target stored in inode */
+		strcpy((char *)&inode.i_block, target);
+	} else {
+		/* Slow symlinks, target stored in the first block */
+		memset(block_buf, 0, fs->blocksize);
+		strcpy(block_buf, target);
+		if (fs->super->s_feature_incompat &
+		    EXT3_FEATURE_INCOMPAT_EXTENTS) {
+			/*
+			 * The extent bmap is setup after the inode and block
+			 * have been written out below.
+			 */
+			inode.i_flags |= EXT4_EXTENTS_FL;
+		}
+	}
+
+	/*
+	 * Write out the inode and inode data block.  The inode generation
+	 * number is assigned by write_new_inode, which means that the
+	 * operations using ino must come after it.
+	 */
+	retval = ext2fs_write_new_inode(fs, ino, &inode);
+	if (retval)
+		goto cleanup;
+
+	if (!fastlink) {
+		retval = ext2fs_bmap2(fs, ino, &inode, NULL, BMAP_SET, 0, NULL,
+				      &blk);
+		if (retval)
+			goto cleanup;
+
+		retval = io_channel_write_blk64(fs->io, blk, 1, block_buf);
+		if (retval)
+			goto cleanup;
+	}
+
+	/*
+	 * Link the symlink into the filesystem hierarchy
+	 */
+	if (name) {
+		retval = ext2fs_lookup(fs, parent, name, strlen(name), 0,
+				       &scratch_ino);
+		if (!retval) {
+			retval = EXT2_ET_FILE_EXISTS;
+			goto cleanup;
+		}
+		if (retval != EXT2_ET_FILE_NOT_FOUND)
+			goto cleanup;
+		retval = ext2fs_link(fs, parent, name, ino, EXT2_FT_SYMLINK);
+		if (retval)
+			goto cleanup;
+	}
+
+	/*
+	 * Update accounting....
+	 */
+	if (!fastlink)
+		ext2fs_block_alloc_stats2(fs, blk, +1);
+	ext2fs_inode_alloc_stats2(fs, ino, +1, 0);
+
+cleanup:
+	if (block_buf)
+		ext2fs_free_mem(&block_buf);
+	return retval;
+}