diff options
| author |   Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-02 14:23:30 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-03-02 14:23:30 -0800 |
| commit | 8966be90304b394fd6a2c5af7b6b3abe2df3889c (patch) | |
| tree | 9893ca0f2e1c97d4ed5d37fee8502a77f0c3b7d2 | |
| parent | Merge branches 'core-urgent-for-linus', 'perf-urgent-for-linus' and 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip (diff) | |
| download | linux-dev-8966be90304b394fd6a2c5af7b6b3abe2df3889c.tar.xz linux-dev-8966be90304b394fd6a2c5af7b6b3abe2df3889c.zip | |
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 <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/dcache.c | 13 | ||||
| -rw-r--r-- | include/linux/dcache.h | 3 |
2 files changed, 10 insertions, 6 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index fe19ac13f75f..138be96e25b6 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -104,7 +104,7 @@ static unsigned int d_hash_shift __read_mostly; static struct hlist_bl_head *dentry_hashtable __read_mostly; -static inline struct hlist_bl_head *d_hash(struct dentry *parent, +static inline struct hlist_bl_head *d_hash(const struct dentry *parent, unsigned long hash) { hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES; @@ -1717,8 +1717,9 @@ EXPORT_SYMBOL(d_add_ci); * child is looked up. Thus, an interlocking stepping of sequence lock checks * is formed, giving integrity down the path walk. */ -struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name, - unsigned *seq, struct inode **inode) +struct dentry *__d_lookup_rcu(const struct dentry *parent, + const struct qstr *name, + unsigned *seqp, struct inode **inode) { unsigned int len = name->len; unsigned int hash = name->hash; @@ -1748,6 +1749,7 @@ struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name, * See Documentation/filesystems/path-lookup.txt for more details. */ hlist_bl_for_each_entry_rcu(dentry, node, b, d_hash) { + unsigned seq; struct inode *i; const char *tname; int tlen; @@ -1756,7 +1758,7 @@ struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name, continue; seqretry: - *seq = read_seqcount_begin(&dentry->d_seq); + seq = read_seqcount_begin(&dentry->d_seq); if (dentry->d_parent != parent) continue; if (d_unhashed(dentry)) @@ -1771,7 +1773,7 @@ seqretry: * edge of memory when walking. If we could load this * atomically some other way, we could drop this check. */ - if (read_seqcount_retry(&dentry->d_seq, *seq)) + if (read_seqcount_retry(&dentry->d_seq, seq)) goto seqretry; if (unlikely(parent->d_flags & DCACHE_OP_COMPARE)) { if (parent->d_op->d_compare(parent, *inode, @@ -1788,6 +1790,7 @@ seqretry: * order to do anything useful with the returned dentry * anyway. */ + *seqp = seq; *inode = i; return dentry; } 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); /** |