projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 4b5397dc PL |
1 | /* |
| 2 | * Squashfs - a compressed read only filesystem for Linux | |
| 3 | * | |
| 4 | * Copyright (c) 2010 | |
| d7f2ff67 | 5 | * Phillip Lougher <[email protected]> |
| 4b5397dc PL |
6 | * |
| 7 | * This program is free software; you can redistribute it and/or | |
| 8 | * modify it under the terms of the GNU General Public License | |
| 9 | * as published by the Free Software Foundation; either version 2, | |
| 10 | * or (at your option) any later version. | |
| 11 | * | |
| 12 | * This program is distributed in the hope that it will be useful, | |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 15 | * GNU General Public License for more details. | |
| 16 | * | |
| 17 | * You should have received a copy of the GNU General Public License | |
| 18 | * along with this program; if not, write to the Free Software | |
| 19 | * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. | |
| 20 | * | |
| 21 | * xattr_id.c | |
| 22 | */ | |
| 23 | ||
| 24 | /* | |
| 25 | * This file implements code to map the 32-bit xattr id stored in the inode | |
| 26 | * into the on disk location of the xattr data. | |
| 27 | */ | |
| 28 | ||
| 29 | #include <linux/fs.h> | |
| 30 | #include <linux/vfs.h> | |
| 31 | #include <linux/slab.h> | |
| 32 | ||
| 33 | #include "squashfs_fs.h" | |
| 34 | #include "squashfs_fs_sb.h" | |
| 4b5397dc | 35 | #include "squashfs.h" |
| 5f3b321d | 36 | #include "xattr.h" |
| 4b5397dc PL |
37 | |
| 38 | /* | |
| 39 | * Map xattr id using the xattr id look up table | |
| 40 | */ | |
| 41 | int squashfs_xattr_lookup(struct super_block *sb, unsigned int index, | |
| aa5b1894 | 42 | int *count, unsigned int *size, unsigned long long *xattr) |
| 4b5397dc PL |
43 | { |
| 44 | struct squashfs_sb_info *msblk = sb->s_fs_info; | |
| 45 | int block = SQUASHFS_XATTR_BLOCK(index); | |
| 46 | int offset = SQUASHFS_XATTR_BLOCK_OFFSET(index); | |
| 47 | u64 start_block = le64_to_cpu(msblk->xattr_id_table[block]); | |
| 48 | struct squashfs_xattr_id id; | |
| 49 | int err; | |
| 50 | ||
| 51 | err = squashfs_read_metadata(sb, &id, &start_block, &offset, | |
| 52 | sizeof(id)); | |
| 53 | if (err < 0) | |
| 54 | return err; | |
| 55 | ||
| 56 | *xattr = le64_to_cpu(id.xattr); | |
| 57 | *size = le32_to_cpu(id.size); | |
| 58 | *count = le32_to_cpu(id.count); | |
| 59 | return 0; | |
| 60 | } | |
| 61 | ||
| 62 | ||
| 63 | /* | |
| 64 | * Read uncompressed xattr id lookup table indexes from disk into memory | |
| 65 | */ | |
| 66 | __le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 start, | |
| 67 | u64 *xattr_table_start, int *xattr_ids) | |
| 68 | { | |
| 69 | unsigned int len; | |
| 82de647e PL |
70 | struct squashfs_xattr_id_table *id_table; |
| 71 | ||
| 72 | id_table = squashfs_read_table(sb, start, sizeof(*id_table)); | |
| 73 | if (IS_ERR(id_table)) | |
| 74 | return (__le64 *) id_table; | |
| 4b5397dc | 75 | |
| 82de647e PL |
76 | *xattr_table_start = le64_to_cpu(id_table->xattr_table_start); |
| 77 | *xattr_ids = le32_to_cpu(id_table->xattr_ids); | |
| 78 | kfree(id_table); | |
| 6f048645 PL |
79 | |
| 80 | /* Sanity check values */ | |
| 81 | ||
| 82 | /* there is always at least one xattr id */ | |
| 83 | if (*xattr_ids == 0) | |
| 84 | return ERR_PTR(-EINVAL); | |
| 85 | ||
| 86 | /* xattr_table should be less than start */ | |
| 87 | if (*xattr_table_start >= start) | |
| 88 | return ERR_PTR(-EINVAL); | |
| 89 | ||
| 4b5397dc PL |
90 | len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids); |
| 91 | ||
| 92 | TRACE("In read_xattr_index_table, length %d\n", len); | |
| 93 | ||
| 82de647e | 94 | return squashfs_read_table(sb, start + sizeof(*id_table), len); |
| 4b5397dc | 95 | } |