From 8966be90304b394fd6a2c5af7b6b3abe2df3889c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 2 Mar 2012 14:23:30 -0800 Subject: vfs: trivial __d_lookup_rcu() cleanups These don't change any semantics, but they clean up the code a bit and mark some arguments appropriately 'const'. They came up as I was doing the word-at-a-time dcache name accessor code, and cleaning this up now allows me to send out a smaller relevant interesting patch for the experimental stuff. Signed-off-by: Linus Torvalds --- include/linux/dcache.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/dcache.h') diff --git a/include/linux/dcache.h b/include/linux/dcache.h index d64a55b23afd..61b24261e07a 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -309,7 +309,8 @@ extern struct dentry *d_ancestor(struct dentry *, struct dentry *); extern struct dentry *d_lookup(struct dentry *, struct qstr *); extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *); extern struct dentry *__d_lookup(struct dentry *, struct qstr *); -extern struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name, +extern struct dentry *__d_lookup_rcu(const struct dentry *parent, + const struct qstr *name, unsigned *seq, struct inode **inode); /** -- cgit v1.2.3-59-g8ed1b From 0145acc202ca613b23b5383e55df3c32a92ad1bf Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 2 Mar 2012 14:32:59 -0800 Subject: vfs: uninline full_name_hash() .. and also use it in lookup_one_len() rather than open-coding it. There aren't any performance-critical users, so inlining it is silly. But it wouldn't matter if it wasn't for the fact that the word-at-a-time dentry name patches want to conditionally replace the function, and uninlining it sets the stage for that. So again, this is a preparatory patch that doesn't change any semantics, and only prepares for a much cleaner and testable word-at-a-time dentry name accessor patch. Signed-off-by: Linus Torvalds --- fs/namei.c | 13 +++++++++---- include/linux/dcache.h | 9 +-------- 2 files changed, 10 insertions(+), 12 deletions(-) (limited to 'include/linux/dcache.h') diff --git a/fs/namei.c b/fs/namei.c index a780ea515c47..ec72fa1acb14 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1374,6 +1374,14 @@ static inline int can_lookup(struct inode *inode) return 1; } +unsigned int full_name_hash(const unsigned char *name, unsigned int len) +{ + unsigned long hash = init_name_hash(); + while (len--) + hash = partial_name_hash(*name++, hash); + return end_name_hash(hash); +} + /* * Name resolution. * This is the basic name resolution function, turning a pathname into @@ -1775,24 +1783,21 @@ static struct dentry *lookup_hash(struct nameidata *nd) struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) { struct qstr this; - unsigned long hash; unsigned int c; WARN_ON_ONCE(!mutex_is_locked(&base->d_inode->i_mutex)); this.name = name; this.len = len; + this.hash = full_name_hash(name, len); if (!len) return ERR_PTR(-EACCES); - hash = init_name_hash(); while (len--) { c = *(const unsigned char *)name++; if (c == '/' || c == '\0') return ERR_PTR(-EACCES); - hash = partial_name_hash(c, hash); } - this.hash = end_name_hash(hash); /* * See if the low-level filesystem might want * to use its own hash.. diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 61b24261e07a..f1c7eb8461be 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -89,14 +89,7 @@ static inline unsigned long end_name_hash(unsigned long hash) } /* Compute the hash for a name string. */ -static inline unsigned int -full_name_hash(const unsigned char *name, unsigned int len) -{ - unsigned long hash = init_name_hash(); - while (len--) - hash = partial_name_hash(*name++, hash); - return end_name_hash(hash); -} +extern unsigned int full_name_hash(const unsigned char *, unsigned int); /* * Try to keep struct dentry aligned on 64 byte cachelines (this will -- cgit v1.2.3-59-g8ed1b From 5707c87f20bca9e76969bb4096149de6ef74cbb9 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 2 Mar 2012 14:47:15 -0800 Subject: vfs: clarify and clean up dentry_cmp() It did some odd things for unclear reasons. As this is one of the functions that gets changed when doing word-at-a-time compares, this is yet another of the "don't change any semantics, but clean things up so that subsequent patches don't get obscured by the cleanups". Signed-off-by: Linus Torvalds --- include/linux/dcache.h | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'include/linux/dcache.h') diff --git a/include/linux/dcache.h b/include/linux/dcache.h index f1c7eb8461be..4270bedd2308 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -54,18 +54,17 @@ extern struct dentry_stat_t dentry_stat; static inline int dentry_cmp(const unsigned char *cs, size_t scount, const unsigned char *ct, size_t tcount) { - int ret; if (scount != tcount) return 1; + do { - ret = (*cs != *ct); - if (ret) - break; + if (*cs != *ct) + return 1; cs++; ct++; tcount--; } while (tcount); - return ret; + return 0; } /* Name hashing routines. Initial hash value */ -- cgit v1.2.3-59-g8ed1b