projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 4534a70b KK |
1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* | |
| 3 | * | |
| 4 | * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved. | |
| 5 | * | |
| 6 | */ | |
| e8b8e97f | 7 | |
| f9767661 KA |
8 | #include <linux/kernel.h> |
| 9 | #include <linux/types.h> | |
| 4534a70b | 10 | |
| 4534a70b KK |
11 | #include "ntfs_fs.h" |
| 12 | ||
| 13 | static inline u16 upcase_unicode_char(const u16 *upcase, u16 chr) | |
| 14 | { | |
| 15 | if (chr < 'a') | |
| 16 | return chr; | |
| 17 | ||
| 18 | if (chr <= 'z') | |
| 19 | return chr - ('a' - 'A'); | |
| 20 | ||
| 21 | return upcase[chr]; | |
| 22 | } | |
| 23 | ||
| 24 | /* | |
| e8b8e97f KA |
25 | * ntfs_cmp_names |
| 26 | * | |
| 4534a70b KK |
27 | * Thanks Kari Argillander <kari.argillander@gmail.com> for idea and implementation 'bothcase' |
| 28 | * | |
| f8d87ed9 | 29 | * Straight way to compare names: |
| e8b8e97f KA |
30 | * - Case insensitive |
| 31 | * - If name equals and 'bothcases' then | |
| 32 | * - Case sensitive | |
| d3624466 | 33 | * 'Straight way' code scans input names twice in worst case. |
| e8b8e97f | 34 | * Optimized code scans input names only once. |
| 4534a70b KK |
35 | */ |
| 36 | int ntfs_cmp_names(const __le16 *s1, size_t l1, const __le16 *s2, size_t l2, | |
| 37 | const u16 *upcase, bool bothcase) | |
| 38 | { | |
| 39 | int diff1 = 0; | |
| 40 | int diff2; | |
| 41 | size_t len = min(l1, l2); | |
| 42 | ||
| 43 | if (!bothcase && upcase) | |
| 44 | goto case_insentive; | |
| 45 | ||
| 46 | for (; len; s1++, s2++, len--) { | |
| 47 | diff1 = le16_to_cpu(*s1) - le16_to_cpu(*s2); | |
| 48 | if (diff1) { | |
| 49 | if (bothcase && upcase) | |
| 50 | goto case_insentive; | |
| 51 | ||
| 52 | return diff1; | |
| 53 | } | |
| 54 | } | |
| 55 | return l1 - l2; | |
| 56 | ||
| 57 | case_insentive: | |
| 58 | for (; len; s1++, s2++, len--) { | |
| 59 | diff2 = upcase_unicode_char(upcase, le16_to_cpu(*s1)) - | |
| 60 | upcase_unicode_char(upcase, le16_to_cpu(*s2)); | |
| 61 | if (diff2) | |
| 62 | return diff2; | |
| 63 | } | |
| 64 | ||
| 65 | diff2 = l1 - l2; | |
| 66 | return diff2 ? diff2 : diff1; | |
| 67 | } | |
| 68 | ||
| 69 | int ntfs_cmp_names_cpu(const struct cpu_str *uni1, const struct le_str *uni2, | |
| 70 | const u16 *upcase, bool bothcase) | |
| 71 | { | |
| 72 | const u16 *s1 = uni1->name; | |
| 73 | const __le16 *s2 = uni2->name; | |
| 74 | size_t l1 = uni1->len; | |
| 75 | size_t l2 = uni2->len; | |
| 76 | size_t len = min(l1, l2); | |
| 77 | int diff1 = 0; | |
| 78 | int diff2; | |
| 79 | ||
| 80 | if (!bothcase && upcase) | |
| 81 | goto case_insentive; | |
| 82 | ||
| 83 | for (; len; s1++, s2++, len--) { | |
| 84 | diff1 = *s1 - le16_to_cpu(*s2); | |
| 85 | if (diff1) { | |
| 86 | if (bothcase && upcase) | |
| 87 | goto case_insentive; | |
| 88 | ||
| 89 | return diff1; | |
| 90 | } | |
| 91 | } | |
| 92 | return l1 - l2; | |
| 93 | ||
| 94 | case_insentive: | |
| 95 | for (; len; s1++, s2++, len--) { | |
| 96 | diff2 = upcase_unicode_char(upcase, *s1) - | |
| 97 | upcase_unicode_char(upcase, le16_to_cpu(*s2)); | |
| 98 | if (diff2) | |
| 99 | return diff2; | |
| 100 | } | |
| 101 | ||
| 102 | diff2 = l1 - l2; | |
| 103 | return diff2 ? diff2 : diff1; | |
| 104 | } | |
| a3a956c7 KK |
105 | |
| 106 | /* Helper function for ntfs_d_hash. */ | |
| 107 | unsigned long ntfs_names_hash(const u16 *name, size_t len, const u16 *upcase, | |
| 108 | unsigned long hash) | |
| 109 | { | |
| 110 | while (len--) { | |
| 111 | unsigned int c = upcase_unicode_char(upcase, *name++); | |
| 112 | hash = partial_name_hash(c, hash); | |
| 113 | } | |
| 114 | ||
| 115 | return hash; | |
| 116 | } |