1e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall/* 2e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * symlink.c --- make a symlink in the filesystem, based on mkdir.c 3e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * 4e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * Copyright (c) 2012, Intel Corporation. 5e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * All Rights Reserved. 6e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * 7e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * %Begin-Header% 8e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * This file may be redistributed under the terms of the GNU Library 9e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * General Public License, version 2. 10e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * %End-Header% 11e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall */ 12e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 13e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#include <stdio.h> 14e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#include <string.h> 15e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#if HAVE_UNISTD_H 16e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#include <unistd.h> 17e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#endif 18e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#include <fcntl.h> 19e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#include <time.h> 20e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#if HAVE_SYS_STAT_H 21e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#include <sys/stat.h> 22e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#endif 23e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#if HAVE_SYS_TYPES_H 24e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#include <sys/types.h> 25e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#endif 26e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 27e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#include "ext2_fs.h" 28e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall#include "ext2fs.h" 29e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 30e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrallerrcode_t ext2fs_symlink(ext2_filsys fs, ext2_ino_t parent, ext2_ino_t ino, 31e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall const char *name, char *target) 32e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall{ 33e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall ext2_extent_handle_t handle; 34e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall errcode_t retval; 35e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall struct ext2_inode inode; 36e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall ext2_ino_t scratch_ino; 37e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall blk64_t blk; 38e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall int fastlink; 39e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall unsigned int target_len; 40e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall char *block_buf = 0; 41e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 42e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 43e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 44e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall /* The Linux kernel doesn't allow for links longer than a block */ 45e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall target_len = strlen(target); 46e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (target_len > fs->blocksize) { 47e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall retval = EXT2_ET_INVALID_ARGUMENT; 48e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall goto cleanup; 49e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall } 50e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 51e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall /* 52e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * Allocate a data block for slow links 53e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall */ 54e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall fastlink = (target_len < sizeof(inode.i_block)); 55e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (!fastlink) { 56e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall retval = ext2fs_new_block2(fs, 0, 0, &blk); 57e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (retval) 58e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall goto cleanup; 59e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall retval = ext2fs_get_mem(fs->blocksize, &block_buf); 60e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (retval) 61e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall goto cleanup; 62e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall } 63e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 64e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall /* 65e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * Allocate an inode, if necessary 66e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall */ 67e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (!ino) { 68e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall retval = ext2fs_new_inode(fs, parent, LINUX_S_IFLNK | 0755, 69e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 0, &ino); 70e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (retval) 71e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall goto cleanup; 72e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall } 73e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 74e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall /* 75e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * Create the inode structure.... 76e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall */ 77e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall memset(&inode, 0, sizeof(struct ext2_inode)); 78e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall inode.i_mode = LINUX_S_IFLNK | 0777; 79e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall inode.i_uid = inode.i_gid = 0; 80e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall ext2fs_iblk_set(fs, &inode, fastlink ? 0 : 1); 81e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall inode.i_links_count = 1; 82e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall inode.i_size = target_len; 83e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall /* The time fields are set by ext2fs_write_new_inode() */ 84e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 85e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (fastlink) { 86e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall /* Fast symlinks, target stored in inode */ 87e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall strcpy((char *)&inode.i_block, target); 88e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall } else { 89e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall /* Slow symlinks, target stored in the first block */ 90e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall memset(block_buf, 0, fs->blocksize); 91e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall strcpy(block_buf, target); 92e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (fs->super->s_feature_incompat & 93e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall EXT3_FEATURE_INCOMPAT_EXTENTS) { 94e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall /* 95e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * The extent bmap is setup after the inode and block 96e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * have been written out below. 97e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall */ 98e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall inode.i_flags |= EXT4_EXTENTS_FL; 99e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall } 100e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall } 101e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 102e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall /* 103e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * Write out the inode and inode data block. The inode generation 104e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * number is assigned by write_new_inode, which means that the 105e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * operations using ino must come after it. 106e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall */ 107e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall retval = ext2fs_write_new_inode(fs, ino, &inode); 108e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (retval) 109e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall goto cleanup; 110e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 111e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (!fastlink) { 112e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall retval = ext2fs_bmap2(fs, ino, &inode, NULL, BMAP_SET, 0, NULL, 113e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall &blk); 114e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (retval) 115e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall goto cleanup; 116e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 117e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall retval = io_channel_write_blk64(fs->io, blk, 1, block_buf); 118e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (retval) 119e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall goto cleanup; 120e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall } 121e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 122e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall /* 123e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * Link the symlink into the filesystem hierarchy 124e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall */ 125e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (name) { 126e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall retval = ext2fs_lookup(fs, parent, name, strlen(name), 0, 127e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall &scratch_ino); 128e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (!retval) { 129e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall retval = EXT2_ET_FILE_EXISTS; 130e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall goto cleanup; 131e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall } 132e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (retval != EXT2_ET_FILE_NOT_FOUND) 133e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall goto cleanup; 134e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall retval = ext2fs_link(fs, parent, name, ino, EXT2_FT_SYMLINK); 135e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (retval) 136e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall goto cleanup; 137e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall } 138e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 139e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall /* 140e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall * Update accounting.... 141e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall */ 142e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (!fastlink) 143e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall ext2fs_block_alloc_stats2(fs, blk, +1); 144e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall ext2fs_inode_alloc_stats2(fs, ino, +1, 0); 145e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall 146e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrallcleanup: 147e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall if (block_buf) 148e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall ext2fs_free_mem(&block_buf); 149e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall return retval; 150e0ed7404719a9ddd2ba427a80db5365c8bad18c0JP Abgrall} 151