| /* |
| * 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 <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; |
| 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; |
| } |