1f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart/* 2f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * symlink.c --- make a symlink in the filesystem, based on mkdir.c 3f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * 4f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * Copyright (c) 2012, Intel Corporation. 5f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * All Rights Reserved. 6f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * 7f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * %Begin-Header% 8f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * This file may be redistributed under the terms of the GNU Library 9f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * General Public License, version 2. 10f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * %End-Header% 11f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart */ 12f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 13f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#include "config.h" 14f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#include <stdio.h> 15f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#include <string.h> 16f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#if HAVE_UNISTD_H 17f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#include <unistd.h> 18f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#endif 19f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#include <fcntl.h> 20f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#include <time.h> 21f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#if HAVE_SYS_STAT_H 22f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#include <sys/stat.h> 23f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#endif 24f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#if HAVE_SYS_TYPES_H 25f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#include <sys/types.h> 26f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#endif 27f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 28f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#include "ext2_fs.h" 29f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart#include "ext2fs.h" 30f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 31f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Harterrcode_t ext2fs_symlink(ext2_filsys fs, ext2_ino_t parent, ext2_ino_t ino, 324e222d9b88b7ff145ad03272acf752c1e7a18964Theodore Ts'o const char *name, const char *target) 33f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart{ 34f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart errcode_t retval; 35f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart struct ext2_inode inode; 36f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart ext2_ino_t scratch_ino; 37f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart blk64_t blk; 388a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong int fastlink, inlinelink; 39e48bf256e99e4923c6193ff78000af18c700d93dTheodore Ts'o unsigned int target_len; 40f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart char *block_buf = 0; 41f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 42f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS); 43f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 44f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart /* The Linux kernel doesn't allow for links longer than a block */ 454e222d9b88b7ff145ad03272acf752c1e7a18964Theodore Ts'o target_len = strnlen(target, fs->blocksize + 1); 46f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (target_len > fs->blocksize) { 47f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart retval = EXT2_ET_INVALID_ARGUMENT; 48f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart goto cleanup; 49f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart } 50f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 51f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart /* 52f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * Allocate a data block for slow links 53f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart */ 544e222d9b88b7ff145ad03272acf752c1e7a18964Theodore Ts'o retval = ext2fs_get_mem(fs->blocksize+1, &block_buf); 554e222d9b88b7ff145ad03272acf752c1e7a18964Theodore Ts'o if (retval) 564e222d9b88b7ff145ad03272acf752c1e7a18964Theodore Ts'o goto cleanup; 574e222d9b88b7ff145ad03272acf752c1e7a18964Theodore Ts'o memset(block_buf, 0, fs->blocksize+1); 584e222d9b88b7ff145ad03272acf752c1e7a18964Theodore Ts'o strncpy(block_buf, target, fs->blocksize); 594e222d9b88b7ff145ad03272acf752c1e7a18964Theodore Ts'o 607b486ec08cda3bc67b7f6bdcbcc9cb5783322e6cDarrick J. Wong memset(&inode, 0, sizeof(struct ext2_inode)); 61f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart fastlink = (target_len < sizeof(inode.i_block)); 62f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (!fastlink) { 637b486ec08cda3bc67b7f6bdcbcc9cb5783322e6cDarrick J. Wong retval = ext2fs_new_block2(fs, ext2fs_find_inode_goal(fs, ino, 647b486ec08cda3bc67b7f6bdcbcc9cb5783322e6cDarrick J. Wong &inode, 657b486ec08cda3bc67b7f6bdcbcc9cb5783322e6cDarrick J. Wong 0), 667b486ec08cda3bc67b7f6bdcbcc9cb5783322e6cDarrick J. Wong NULL, &blk); 67f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (retval) 68f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart goto cleanup; 69f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart } 70f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 71f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart /* 72f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * Allocate an inode, if necessary 73f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart */ 74f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (!ino) { 75f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart retval = ext2fs_new_inode(fs, parent, LINUX_S_IFLNK | 0755, 76f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 0, &ino); 77f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (retval) 78f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart goto cleanup; 79f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart } 80f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 81f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart /* 82f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * Create the inode structure.... 83f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart */ 84f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart inode.i_mode = LINUX_S_IFLNK | 0777; 85f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart inode.i_uid = inode.i_gid = 0; 86f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart inode.i_links_count = 1; 8797c607b1a25e1f4e83bf246c76b679d91470f5dcDarrick J. Wong ext2fs_inode_size_set(fs, &inode, target_len); 88f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart /* The time fields are set by ext2fs_write_new_inode() */ 89f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 908a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong inlinelink = !fastlink && 9177b3e9871877fce9908b0696250787fd6ea61af9Darrick J. Wong ext2fs_has_feature_inline_data(fs->super) && 928a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong (target_len < fs->blocksize); 93f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (fastlink) { 94f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart /* Fast symlinks, target stored in inode */ 95f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart strcpy((char *)&inode.i_block, target); 968a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong } else if (inlinelink) { 978a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong /* Try inserting an inline data symlink */ 988a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong inode.i_flags |= EXT4_INLINE_DATA_FL; 998a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong retval = ext2fs_write_new_inode(fs, ino, &inode); 1008a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong if (retval) 1018a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong goto cleanup; 1024e222d9b88b7ff145ad03272acf752c1e7a18964Theodore Ts'o retval = ext2fs_inline_data_set(fs, ino, &inode, block_buf, 1038a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong target_len); 1048a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong if (retval) { 1058a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong inode.i_flags &= ~EXT4_INLINE_DATA_FL; 1068a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong inlinelink = 0; 1078a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong goto need_block; 1088a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong } 1098a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong retval = ext2fs_read_inode(fs, ino, &inode); 1108a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong if (retval) 1118a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong goto cleanup; 112f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart } else { 1138a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wongneed_block: 114f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart /* Slow symlinks, target stored in the first block */ 1154e222d9b88b7ff145ad03272acf752c1e7a18964Theodore Ts'o ext2fs_iblk_set(fs, &inode, 1); 11677b3e9871877fce9908b0696250787fd6ea61af9Darrick J. Wong if (ext2fs_has_feature_extents(fs->super)) { 117f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart /* 118f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * The extent bmap is setup after the inode and block 119f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * have been written out below. 120f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart */ 121f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart inode.i_flags |= EXT4_EXTENTS_FL; 122f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart } 123f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart } 124f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 125f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart /* 126f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * Write out the inode and inode data block. The inode generation 127f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * number is assigned by write_new_inode, which means that the 128f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * operations using ino must come after it. 129f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart */ 1308a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong if (inlinelink) 1318a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong retval = ext2fs_write_inode(fs, ino, &inode); 1328a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong else 1338a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong retval = ext2fs_write_new_inode(fs, ino, &inode); 134f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (retval) 135f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart goto cleanup; 136f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 1378a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong if (!fastlink && !inlinelink) { 13862f17f36031102a2a40fac338e063c556f73b94aDarrick J. Wong retval = ext2fs_bmap2(fs, ino, &inode, NULL, BMAP_SET, 0, NULL, 13962f17f36031102a2a40fac338e063c556f73b94aDarrick J. Wong &blk); 140f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (retval) 141f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart goto cleanup; 142f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 14362f17f36031102a2a40fac338e063c556f73b94aDarrick J. Wong retval = io_channel_write_blk64(fs->io, blk, 1, block_buf); 14462f17f36031102a2a40fac338e063c556f73b94aDarrick J. Wong if (retval) 14562f17f36031102a2a40fac338e063c556f73b94aDarrick J. Wong goto cleanup; 146f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart } 147f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 148f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart /* 149f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * Link the symlink into the filesystem hierarchy 150f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart */ 151f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (name) { 152f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart retval = ext2fs_lookup(fs, parent, name, strlen(name), 0, 153f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart &scratch_ino); 154f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (!retval) { 155f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart retval = EXT2_ET_FILE_EXISTS; 156f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart goto cleanup; 157f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart } 158f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (retval != EXT2_ET_FILE_NOT_FOUND) 159f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart goto cleanup; 160f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart retval = ext2fs_link(fs, parent, name, ino, EXT2_FT_SYMLINK); 161f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (retval) 162f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart goto cleanup; 163f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart } 164f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 165f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart /* 166f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart * Update accounting.... 167f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart */ 1688a17df7195430f55345c515a9cdbc4a8da5cbbd9Darrick J. Wong if (!fastlink && !inlinelink) 169f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart ext2fs_block_alloc_stats2(fs, blk, +1); 170f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart ext2fs_inode_alloc_stats2(fs, ino, +1, 0); 171f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart 172f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hartcleanup: 173f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart if (block_buf) 174f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart ext2fs_free_mem(&block_buf); 175f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart return retval; 176f01c1a6bce5e6674cbfa5260db1691bca01a4410Darren Hart} 177