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-rw-r--r--lib/ext2fs/symlink.c159
1 files changed, 159 insertions, 0 deletions
diff --git a/lib/ext2fs/symlink.c b/lib/ext2fs/symlink.c
new file mode 100644
index 00000000..da6e3a8a
--- /dev/null
+++ b/lib/ext2fs/symlink.c
@@ -0,0 +1,159 @@
+/*
+ * 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)
+{
+ ext2_extent_handle_t handle;
+ errcode_t retval;
+ struct ext2_inode inode;
+ ext2_ino_t scratch_ino;
+ blk64_t blk;
+ int fastlink;
+ 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;
+ } else {
+ inode.i_block[0] = blk;
+ }
+ }
+
+ /*
+ * 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 = io_channel_write_blk(fs->io, blk, 1, block_buf);
+ if (retval)
+ goto cleanup;
+
+ if (fs->super->s_feature_incompat &
+ EXT3_FEATURE_INCOMPAT_EXTENTS) {
+ retval = ext2fs_extent_open2(fs, ino, &inode, &handle);
+ if (retval)
+ goto cleanup;
+ retval = ext2fs_extent_set_bmap(handle, 0, blk, 0);
+ ext2fs_extent_free(handle);
+ 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;
+}