| Message ID | 20200707113123.3429337-2-drosen@google.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Prepare for upcoming Casefolding/Encryption patches | expand |
Daniel Rosenberg <drosen@google.com> writes: > 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 allocates 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>
On Tue, Jul 07, 2020 at 04:31:20AM -0700, Daniel Rosenberg wrote: > 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 allocates 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> You can add: Reviewed-by: Eric Biggers <ebiggers@google.com> If you have a chance please fix the grammar in the commit message though: "The existing d_hash implementations for casefolding allocate memory within rcu-walk. By avoiding this we can be more efficient and avoid worrying about a failed allocation." - Eric
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) { diff --git a/include/linux/unicode.h b/include/linux/unicode.h index 990aa97d8049..74484d44c755 100644 --- a/include/linux/unicode.h +++ b/include/linux/unicode.h @@ -27,6 +27,9 @@ int utf8_normalize(const struct unicode_map *um, const struct qstr *str, int utf8_casefold(const struct unicode_map *um, const struct qstr *str, unsigned char *dest, size_t dlen); +int utf8_casefold_hash(const struct unicode_map *um, const void *salt, + struct qstr *str); + struct unicode_map *utf8_load(const char *version); void utf8_unload(struct unicode_map *um);
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 allocates 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> --- fs/unicode/utf8-core.c | 23 ++++++++++++++++++++++- include/linux/unicode.h | 3 +++ 2 files changed, 25 insertions(+), 1 deletion(-)