From 3d7bfea8b8378277a25b42b28fe5a2a5ca76a7cf Mon Sep 17 00:00:00 2001 From: Daniel Rosenberg <drosen@google.com> Date: Wed, 8 Jul 2020 02:12:34 -0700 Subject: unicode: Add utf8_casefold_hash This adds a case insensitive hash function to allow taking the hash without needing to allocate a casefolded copy of the string. The existing d_hash implementations for casefolding allocate memory within rcu-walk, by avoiding it we can be more efficient and avoid worrying about a failed allocation. Signed-off-by: Daniel Rosenberg <drosen@google.com> Reviewed-by: Gabriel Krisman Bertazi <krisman@collabora.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> --- fs/unicode/utf8-core.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) (limited to 'fs/unicode') diff --git a/fs/unicode/utf8-core.c b/fs/unicode/utf8-core.c index 2a878b739115..dc25823bfed9 100644 --- a/fs/unicode/utf8-core.c +++ b/fs/unicode/utf8-core.c @@ -6,6 +6,7 @@ #include <linux/parser.h> #include <linux/errno.h> #include <linux/unicode.h> +#include <linux/stringhash.h> #include "utf8n.h" @@ -122,9 +123,29 @@ int utf8_casefold(const struct unicode_map *um, const struct qstr *str, } return -EINVAL; } - EXPORT_SYMBOL(utf8_casefold); +int utf8_casefold_hash(const struct unicode_map *um, const void *salt, + struct qstr *str) +{ + const struct utf8data *data = utf8nfdicf(um->version); + struct utf8cursor cur; + int c; + unsigned long hash = init_name_hash(salt); + + if (utf8ncursor(&cur, data, str->name, str->len) < 0) + return -EINVAL; + + while ((c = utf8byte(&cur))) { + if (c < 0) + return -EINVAL; + hash = partial_name_hash((unsigned char)c, hash); + } + str->hash = end_name_hash(hash); + return 0; +} +EXPORT_SYMBOL(utf8_casefold_hash); + int utf8_normalize(const struct unicode_map *um, const struct qstr *str, unsigned char *dest, size_t dlen) { -- cgit v1.2.3-58-ga151