diff options
| -rw-r--r-- | fs/dcache.c | 3 | ||||
| -rw-r--r-- | fs/namei.c | 51 | ||||
| -rw-r--r-- | include/linux/stringhash.h | 8 |
3 files changed, 53 insertions, 9 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index d5ecc6e477da..19b751806789 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1653,8 +1653,7 @@ struct dentry *d_alloc_name(struct dentry *parent, const char *name) struct qstr q; q.name = name; - q.len = strlen(name); - q.hash = full_name_hash(q.name, q.len); + q.hash_len = hashlen_string(name); return d_alloc(parent, &q); } EXPORT_SYMBOL(d_alloc_name); diff --git a/fs/namei.c b/fs/namei.c index 42f8ca038254..dd98d43a54f8 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1822,19 +1822,20 @@ static inline unsigned long mix_hash(unsigned long hash) #endif -unsigned int full_name_hash(const unsigned char *name, unsigned int len) +/* Return the hash of a string of known length */ +unsigned int full_name_hash(const char *name, unsigned int len) { unsigned long a, hash = 0; for (;;) { + if (!len) + goto done; a = load_unaligned_zeropad(name); if (len < sizeof(unsigned long)) break; hash = mix_hash(hash + a); name += sizeof(unsigned long); len -= sizeof(unsigned long); - if (!len) - goto done; } hash += a & bytemask_from_count(len); done: @@ -1842,6 +1843,29 @@ done: } EXPORT_SYMBOL(full_name_hash); +/* Return the "hash_len" (hash and length) of a null-terminated string */ +u64 hashlen_string(const char *name) +{ + unsigned long a, adata, mask, hash, len; + const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS; + + hash = a = 0; + len = -sizeof(unsigned long); + do { + hash = mix_hash(hash + a); + len += sizeof(unsigned long); + a = load_unaligned_zeropad(name+len); + } while (!has_zero(a, &adata, &constants)); + + adata = prep_zero_mask(a, adata, &constants); + mask = create_zero_mask(adata); + hash += a & zero_bytemask(mask); + len += find_zero(mask); + + return hashlen_create(fold_hash(hash), len); +} +EXPORT_SYMBOL(hashlen_string); + /* * Calculate the length and hash of the path component, and * return the "hash_len" as the result. @@ -1872,15 +1896,32 @@ static inline u64 hash_name(const char *name) #else -unsigned int full_name_hash(const unsigned char *name, unsigned int len) +/* Return the hash of a string of known length */ +unsigned int full_name_hash(const char *name, unsigned int len) { unsigned long hash = init_name_hash(); while (len--) - hash = partial_name_hash(*name++, hash); + hash = partial_name_hash((unsigned char)*name++, hash); return end_name_hash(hash); } EXPORT_SYMBOL(full_name_hash); +/* Return the "hash_len" (hash and length) of a null-terminated string */ +u64 hash_string(const char *name) +{ + unsigned long hash = init_name_hash(); + unsigned long len = 0, c; + + c = (unsigned char)*name; + do { + len++; + hash = partial_name_hash(c, hash); + c = (unsigned char)name[len]; + } while (c); + return hashlen_create(end_name_hash(hash), len); +} +EXPORT_SYMBOL(hash_string); + /* * We know there's a real path component here of at least * one character. diff --git a/include/linux/stringhash.h b/include/linux/stringhash.h index 2eaaaf6d2776..451771d9b9c0 100644 --- a/include/linux/stringhash.h +++ b/include/linux/stringhash.h @@ -1,7 +1,8 @@ #ifndef __LINUX_STRINGHASH_H #define __LINUX_STRINGHASH_H -#include <linux/types.h> +#include <linux/compiler.h> /* For __pure */ +#include <linux/types.h> /* For u32, u64 */ /* * Routines for hashing strings of bytes to a 32-bit hash value. @@ -59,7 +60,7 @@ static inline unsigned long end_name_hash(unsigned long hash) * * If not set, this falls back to a wrapper around the preceding. */ -extern unsigned int full_name_hash(const unsigned char *, unsigned int); +extern unsigned int __pure full_name_hash(const char *, unsigned int); /* * A hash_len is a u64 with the hash of a string in the low @@ -69,4 +70,7 @@ extern unsigned int full_name_hash(const unsigned char *, unsigned int); #define hashlen_len(hashlen) ((u32)((hashlen) >> 32)) #define hashlen_create(hash, len) ((u64)(len)<<32 | (u32)(hash)) +/* Return the "hash_len" (hash and length) of a null-terminated string */ +extern u64 __pure hashlen_string(const char *name); + #endif /* __LINUX_STRINGHASH_H */ |