2 * symlink.c --- make a symlink in the filesystem, based on mkdir.c
4 * Copyright (c) 2012, Intel Corporation.
8 * This file may be redistributed under the terms of the GNU Library
9 * General Public License, version 2.
25 #include <sys/types.h>
31 errcode_t ext2fs_symlink(ext2_filsys fs, ext2_ino_t parent, ext2_ino_t ino,
32 const char *name, char *target)
35 struct ext2_inode inode;
36 ext2_ino_t scratch_ino;
39 unsigned int target_len;
42 EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
44 /* The Linux kernel doesn't allow for links longer than a block */
45 target_len = strlen(target);
46 if (target_len > fs->blocksize) {
47 retval = EXT2_ET_INVALID_ARGUMENT;
52 * Allocate a data block for slow links
54 fastlink = (target_len < sizeof(inode.i_block));
56 retval = ext2fs_new_block2(fs, 0, 0, &blk);
59 retval = ext2fs_get_mem(fs->blocksize, &block_buf);
65 * Allocate an inode, if necessary
68 retval = ext2fs_new_inode(fs, parent, LINUX_S_IFLNK | 0755,
75 * Create the inode structure....
77 memset(&inode, 0, sizeof(struct ext2_inode));
78 inode.i_mode = LINUX_S_IFLNK | 0777;
79 inode.i_uid = inode.i_gid = 0;
80 ext2fs_iblk_set(fs, &inode, fastlink ? 0 : 1);
81 inode.i_links_count = 1;
82 ext2fs_inode_size_set(fs, &inode, target_len);
83 /* The time fields are set by ext2fs_write_new_inode() */
86 /* Fast symlinks, target stored in inode */
87 strcpy((char *)&inode.i_block, target);
89 /* Slow symlinks, target stored in the first block */
90 memset(block_buf, 0, fs->blocksize);
91 strncpy(block_buf, target, fs->blocksize);
92 if (fs->super->s_feature_incompat &
93 EXT3_FEATURE_INCOMPAT_EXTENTS) {
95 * The extent bmap is setup after the inode and block
96 * have been written out below.
98 inode.i_flags |= EXT4_EXTENTS_FL;
103 * Write out the inode and inode data block. The inode generation
104 * number is assigned by write_new_inode, which means that the
105 * operations using ino must come after it.
107 retval = ext2fs_write_new_inode(fs, ino, &inode);
112 retval = ext2fs_bmap2(fs, ino, &inode, NULL, BMAP_SET, 0, NULL,
117 retval = io_channel_write_blk64(fs->io, blk, 1, block_buf);
123 * Link the symlink into the filesystem hierarchy
126 retval = ext2fs_lookup(fs, parent, name, strlen(name), 0,
129 retval = EXT2_ET_FILE_EXISTS;
132 if (retval != EXT2_ET_FILE_NOT_FOUND)
134 retval = ext2fs_link(fs, parent, name, ino, EXT2_FT_SYMLINK);
140 * Update accounting....
143 ext2fs_block_alloc_stats2(fs, blk, +1);
144 ext2fs_inode_alloc_stats2(fs, ino, +1, 0);
148 ext2fs_free_mem(&block_buf);