Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
+10
-6
+8
-5
fs/dcache.c
+8
-5
fs/dcache.c
···
104
104
105
105
static struct hlist_bl_head *dentry_hashtable __read_mostly;
106
106
107
-
static inline struct hlist_bl_head *d_hash(struct dentry *parent,
107
+
static inline struct hlist_bl_head *d_hash(const struct dentry *parent,
108
108
unsigned long hash)
109
109
{
110
110
hash += ((unsigned long) parent ^ GOLDEN_RATIO_PRIME) / L1_CACHE_BYTES;
···
1717
1717
* child is looked up. Thus, an interlocking stepping of sequence lock checks
1718
1718
* is formed, giving integrity down the path walk.
1719
1719
*/
1720
-
struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name,
1721
-
unsigned *seq, struct inode **inode)
1720
+
struct dentry *__d_lookup_rcu(const struct dentry *parent,
1721
+
const struct qstr *name,
1722
+
unsigned *seqp, struct inode **inode)
1722
1723
{
1723
1724
unsigned int len = name->len;
1724
1725
unsigned int hash = name->hash;
···
1749
1748
* See Documentation/filesystems/path-lookup.txt for more details.
1750
1749
*/
1751
1750
hlist_bl_for_each_entry_rcu(dentry, node, b, d_hash) {
1751
+
unsigned seq;
1752
1752
struct inode *i;
1753
1753
const char *tname;
1754
1754
int tlen;
···
1758
1756
continue;
1759
1757
1760
1758
seqretry:
1761
-
*seq = read_seqcount_begin(&dentry->d_seq);
1759
+
seq = read_seqcount_begin(&dentry->d_seq);
1762
1760
if (dentry->d_parent != parent)
1763
1761
continue;
1764
1762
if (d_unhashed(dentry))
···
1773
1771
* edge of memory when walking. If we could load this
1774
1772
* atomically some other way, we could drop this check.
1775
1773
*/
1776
-
if (read_seqcount_retry(&dentry->d_seq, *seq))
1774
+
if (read_seqcount_retry(&dentry->d_seq, seq))
1777
1775
goto seqretry;
1778
1776
if (unlikely(parent->d_flags & DCACHE_OP_COMPARE)) {
1779
1777
if (parent->d_op->d_compare(parent, *inode,
···
1790
1788
* order to do anything useful with the returned dentry
1791
1789
* anyway.
1792
1790
*/
1791
+
*seqp = seq;
1793
1792
*inode = i;
1794
1793
return dentry;
1795
1794
}
+2
-1
include/linux/dcache.h
+2
-1
include/linux/dcache.h
···
309
309
extern struct dentry *d_lookup(struct dentry *, struct qstr *);
310
310
extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *);
311
311
extern struct dentry *__d_lookup(struct dentry *, struct qstr *);
312
-
extern struct dentry *__d_lookup_rcu(struct dentry *parent, struct qstr *name,
312
+
extern struct dentry *__d_lookup_rcu(const struct dentry *parent,
313
+
const struct qstr *name,
313
314
unsigned *seq, struct inode **inode);
314
315
315
316
/**