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authorLinus Torvalds <torvalds@linux-foundation.org>2012-03-02 14:23:30 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-02 14:23:30 -0800
commit8966be90304b394fd6a2c5af7b6b3abe2df3889c (patch)
tree9893ca0f2e1c97d4ed5d37fee8502a77f0c3b7d2
parent2273d5ccb882106a74c7b780a6bfa16fb210cd24 (diff)
downloadlinux-stericsson-8966be90304b394fd6a2c5af7b6b3abe2df3889c.tar.gz
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.c13
-rw-r--r--include/linux/dcache.h3
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);
/**