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Diffstat (limited to 'fs/dcache.c')
-rw-r--r--fs/dcache.c41
1 files changed, 32 insertions, 9 deletions
diff --git a/fs/dcache.c b/fs/dcache.c
index 16a53cc2cc02..bcbdb33fcc20 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;
@@ -137,6 +137,26 @@ int proc_nr_dentry(ctl_table *table, int write, void __user *buffer,
}
#endif
+/*
+ * Compare 2 name strings, return 0 if they match, otherwise non-zero.
+ * The strings are both count bytes long, and count is non-zero.
+ */
+static inline int dentry_cmp(const unsigned char *cs, size_t scount,
+ const unsigned char *ct, size_t tcount)
+{
+ if (scount != tcount)
+ return 1;
+
+ do {
+ if (*cs != *ct)
+ return 1;
+ cs++;
+ ct++;
+ tcount--;
+ } while (tcount);
+ return 0;
+}
+
static void __d_free(struct rcu_head *head)
{
struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu);
@@ -1717,8 +1737,9 @@ 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 +1769,7 @@ 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 +1778,7 @@ 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 +1793,7 @@ 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 +1810,7 @@ seqretry:
* order to do anything useful with the returned dentry
* anyway.
*/
+ *seqp = seq;
*inode = i;
return dentry;
}
@@ -2968,7 +2991,7 @@ __setup("dhash_entries=", set_dhash_entries);
static void __init dcache_init_early(void)
{
- int loop;
+ unsigned int loop;
/* If hashes are distributed across NUMA nodes, defer
* hash allocation until vmalloc space is available.
@@ -2986,13 +3009,13 @@ static void __init dcache_init_early(void)
&d_hash_mask,
0);
- for (loop = 0; loop < (1 << d_hash_shift); loop++)
+ for (loop = 0; loop < (1U << d_hash_shift); loop++)
INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
}
static void __init dcache_init(void)
{
- int loop;
+ unsigned int loop;
/*
* A constructor could be added for stable state like the lists,
@@ -3016,7 +3039,7 @@ static void __init dcache_init(void)
&d_hash_mask,
0);
- for (loop = 0; loop < (1 << d_hash_shift); loop++)
+ for (loop = 0; loop < (1U << d_hash_shift); loop++)
INIT_HLIST_BL_HEAD(dentry_hashtable + loop);
}