diff options
| -rw-r--r-- | fs/namei.c | 68 |
1 files changed, 46 insertions, 22 deletions
diff --git a/fs/namei.c b/fs/namei.c index 40929d3cdf76..928cbc856d5b 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2163,9 +2163,11 @@ EXPORT_SYMBOL(hashlen_string); /* * Calculate the length and hash of the path component, and - * return the "hash_len" as the result. + * return the length as the result. */ -static inline unsigned long hash_name(struct nameidata *nd, const char *name) +static inline unsigned long hash_name(struct nameidata *nd, + const char *name, + unsigned long *lastword) { unsigned long a = 0, b, x = 0, y = (unsigned long)nd->path.dentry; unsigned long adata, bdata, mask, len; @@ -2185,7 +2187,9 @@ inside: adata = prep_zero_mask(a, adata, &constants); bdata = prep_zero_mask(b, bdata, &constants); mask = create_zero_mask(adata | bdata); - x ^= a & zero_bytemask(mask); + a &= zero_bytemask(mask); + *lastword = a; + x ^= a; len += find_zero(mask); nd->last.hash = fold_hash(x, y); @@ -2193,6 +2197,15 @@ inside: return len; } +/* + * Note that the 'last' word is always zero-masked, but + * was loaded as a possibly big-endian word. + */ +#ifdef __BIG_ENDIAN + #define LAST_WORD_IS_DOT (0x2eul << (BITS_PER_LONG-8)) + #define LAST_WORD_IS_DOTDOT (0x2e2eul << (BITS_PER_LONG-16)) +#endif + #else /* !CONFIG_DCACHE_WORD_ACCESS: Slow, byte-at-a-time version */ /* Return the hash of a string of known length */ @@ -2225,17 +2238,19 @@ EXPORT_SYMBOL(hashlen_string); * We know there's a real path component here of at least * one character. */ -static inline unsigned long hash_name(struct nameidata *nd, const char *name) +static inline unsigned long hash_name(struct nameidata *nd, const char *name, unsigned long *lastword) { unsigned long hash = init_name_hash(nd->path.dentry); - unsigned long len = 0, c; + unsigned long len = 0, c, last = 0; c = (unsigned char)*name; do { + last = (last << 8) + c; len++; hash = partial_name_hash(c, hash); c = (unsigned char)name[len]; } while (c && c != '/'); + *lastword = last; nd->last.hash = end_name_hash(hash); nd->last.len = len; return len; @@ -2243,6 +2258,11 @@ static inline unsigned long hash_name(struct nameidata *nd, const char *name) #endif +#ifndef LAST_WORD_IS_DOT + #define LAST_WORD_IS_DOT 0x2e + #define LAST_WORD_IS_DOTDOT 0x2e2e +#endif + /* * Name resolution. * This is the basic name resolution function, turning a pathname into @@ -2271,8 +2291,8 @@ static int link_path_walk(const char *name, struct nameidata *nd) for(;;) { struct mnt_idmap *idmap; const char *link; + unsigned long lastword; unsigned int len; - int type; idmap = mnt_idmap(nd->path.mnt); err = may_lookup(idmap, nd); @@ -2280,25 +2300,29 @@ static int link_path_walk(const char *name, struct nameidata *nd) return err; nd->last.name = name; - len = hash_name(nd, name); + len = hash_name(nd, name, &lastword); name += len; - type = LAST_NORM; - /* We know len is at least 1, so compare against 2 */ - if (len <= 2 && name[-1] == '.') { - if (len == 2) { - if (name[-2] == '.') { - type = LAST_DOTDOT; - nd->state |= ND_JUMPED; - } - } else { - type = LAST_DOT; - } - } - nd->last_type = type; - if (likely(type == LAST_NORM)) { - struct dentry *parent = nd->path.dentry; + switch(lastword) { + case LAST_WORD_IS_DOTDOT: + if (len != 2) + goto normal; + nd->last_type = LAST_DOTDOT; + nd->state |= ND_JUMPED; + break; + + case LAST_WORD_IS_DOT: + if (len != 1) + goto normal; + nd->last_type = LAST_DOT; + break; + + default: + normal: + nd->last_type = LAST_NORM; nd->state &= ~ND_JUMPED; + + struct dentry *parent = nd->path.dentry; if (unlikely(parent->d_flags & DCACHE_OP_HASH)) { err = parent->d_op->d_hash(parent, &nd->last); if (err < 0) |