| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * symlink.c |
| 3 | * |
| 4 | * PURPOSE |
| 5 | * Symlink handling routines for the OSTA-UDF(tm) filesystem. |
| 6 | * |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 7 | * COPYRIGHT |
| 8 | * This file is distributed under the terms of the GNU General Public |
| 9 | * License (GPL). Copies of the GPL can be obtained from: |
| 10 | * ftp://prep.ai.mit.edu/pub/gnu/GPL |
| 11 | * Each contributing author retains all rights to their own work. |
| 12 | * |
| 13 | * (C) 1998-2001 Ben Fennema |
| 14 | * (C) 1999 Stelias Computing Inc |
| 15 | * |
| 16 | * HISTORY |
| 17 | * |
| 18 | * 04/16/99 blf Created. |
| 19 | * |
| 20 | */ |
| 21 | |
| 22 | #include "udfdecl.h" |
| 23 | #include <asm/uaccess.h> |
| 24 | #include <linux/errno.h> |
| 25 | #include <linux/fs.h> |
| 26 | #include <linux/udf_fs.h> |
| 27 | #include <linux/time.h> |
| 28 | #include <linux/mm.h> |
| 29 | #include <linux/stat.h> |
| 30 | #include <linux/slab.h> |
| 31 | #include <linux/pagemap.h> |
| 32 | #include <linux/smp_lock.h> |
| 33 | #include <linux/buffer_head.h> |
| 34 | #include "udf_i.h" |
| 35 | |
| 36 | static void udf_pc_to_char(struct super_block *sb, char *from, int fromlen, char *to) |
| 37 | { |
| 38 | struct pathComponent *pc; |
| 39 | int elen = 0; |
| 40 | char *p = to; |
| 41 | |
| 42 | while (elen < fromlen) |
| 43 | { |
| 44 | pc = (struct pathComponent *)(from + elen); |
| 45 | switch (pc->componentType) |
| 46 | { |
| 47 | case 1: |
| 48 | if (pc->lengthComponentIdent == 0) |
| 49 | { |
| 50 | p = to; |
| 51 | *p++ = '/'; |
| 52 | } |
| 53 | break; |
| 54 | case 3: |
| 55 | memcpy(p, "../", 3); |
| 56 | p += 3; |
| 57 | break; |
| 58 | case 4: |
| 59 | memcpy(p, "./", 2); |
| 60 | p += 2; |
| 61 | /* that would be . - just ignore */ |
| 62 | break; |
| 63 | case 5: |
| 64 | p += udf_get_filename(sb, pc->componentIdent, p, pc->lengthComponentIdent); |
| 65 | *p++ = '/'; |
| 66 | break; |
| 67 | } |
| 68 | elen += sizeof(struct pathComponent) + pc->lengthComponentIdent; |
| 69 | } |
| 70 | if (p > to+1) |
| 71 | p[-1] = '\0'; |
| 72 | else |
| 73 | p[0] = '\0'; |
| 74 | } |
| 75 | |
| 76 | static int udf_symlink_filler(struct file *file, struct page *page) |
| 77 | { |
| 78 | struct inode *inode = page->mapping->host; |
| 79 | struct buffer_head *bh = NULL; |
| 80 | char *symlink; |
| 81 | int err = -EIO; |
| 82 | char *p = kmap(page); |
| 83 | |
| 84 | lock_kernel(); |
| 85 | if (UDF_I_ALLOCTYPE(inode) == ICBTAG_FLAG_AD_IN_ICB) |
| 86 | symlink = UDF_I_DATA(inode) + UDF_I_LENEATTR(inode); |
| 87 | else |
| 88 | { |
| 89 | bh = sb_bread(inode->i_sb, udf_block_map(inode, 0)); |
| 90 | |
| 91 | if (!bh) |
| 92 | goto out; |
| 93 | |
| 94 | symlink = bh->b_data; |
| 95 | } |
| 96 | |
| 97 | udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p); |
| 98 | udf_release_data(bh); |
| 99 | |
| 100 | unlock_kernel(); |
| 101 | SetPageUptodate(page); |
| 102 | kunmap(page); |
| 103 | unlock_page(page); |
| 104 | return 0; |
| 105 | out: |
| 106 | unlock_kernel(); |
| 107 | SetPageError(page); |
| 108 | kunmap(page); |
| 109 | unlock_page(page); |
| 110 | return err; |
| 111 | } |
| 112 | |
| 113 | /* |
| 114 | * symlinks can't do much... |
| 115 | */ |
| 116 | struct address_space_operations udf_symlink_aops = { |
| 117 | .readpage = udf_symlink_filler, |
| 118 | }; |