Negative dentries are still invalidated, triggering a lookup in the
disk.
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxxxx>
---
fs/dcache.c | 43 +++++++++++++++++++++++++++++++++---------
fs/namei.c | 5 +++--
include/linux/dcache.h | 8 ++++++--
3 files changed, 43 insertions(+), 13 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 7c38f39958bc..4bd28d7caa53 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2049,6 +2049,16 @@ struct dentry *d_obtain_root(struct inode *inode)
}
EXPORT_SYMBOL(d_obtain_root);
+static inline bool d_same_name_ci(const struct dentry *dentry,
+ const struct dentry *parent,
+ const struct qstr *name)
+{
+ return parent->d_op->d_compare_ci(dentry,
+ dentry->d_name.len,
+ dentry->d_name.name,
+ name) == 0;
+}
+
/**
* d_add_ci - lookup or allocate new dentry with case-exact name
* @inode: the inode case-insensitive lookup has found
@@ -2122,6 +2132,7 @@ static inline bool d_same_name(const struct dentry *dentry,
* @parent: parent dentry
* @name: qstr of name we wish to find
* @seqp: returns d_seq value at the point where the dentry was found
+ * @ci_lookup: Whether d_lookup_rcu should do a CI lookup
* Returns: dentry, or NULL
*
* __d_lookup_rcu is the dcache lookup function for rcu-walk name
@@ -2148,7 +2159,7 @@ static inline bool d_same_name(const struct dentry *dentry,
*/
struct dentry *__d_lookup_rcu(const struct dentry *parent,
const struct qstr *name,
- unsigned *seqp)
+ unsigned *seqp, int ci_lookup)
{
u64 hashlen = name->hash_len;
const unsigned char *str = name->name;
@@ -2215,9 +2226,16 @@ struct dentry *__d_lookup_rcu(const struct dentry *parent,
cpu_relax();
goto seqretry;
}
- if (parent->d_op->d_compare(dentry,
- tlen, tname, name) != 0)
- continue;
+
+ if (ci_lookup) {
+ if (parent->d_op->d_compare_ci(dentry, tlen,
+ tname, name) != 0)
+ continue;
+ } else {
+ if (parent->d_op->d_compare(dentry, tlen,
+ tname, name) != 0)
+ continue;
+ }
} else {
if (dentry->d_name.hash_len != hashlen)
continue;
@@ -2248,7 +2266,7 @@ struct dentry *d_lookup(const struct dentry *parent, const struct qstr *name)
do {
seq = read_seqbegin(&rename_lock);
- dentry = __d_lookup(parent, name);
+ dentry = __d_lookup(parent, name, 0);
if (dentry)
break;
} while (read_seqretry(&rename_lock, seq));
@@ -2260,6 +2278,7 @@ EXPORT_SYMBOL(d_lookup);
* __d_lookup - search for a dentry (racy)
* @parent: parent dentry
* @name: qstr of name we wish to find
+ * @ci_lookup: Whether d_lookup_rcu should do a CI lookup
* Returns: dentry, or NULL
*
* __d_lookup is like d_lookup, however it may (rarely) return a
@@ -2271,7 +2290,8 @@ EXPORT_SYMBOL(d_lookup);
*
* __d_lookup callers must be commented.
*/
-struct dentry *__d_lookup(const struct dentry *parent, const struct qstr *name)
+struct dentry *__d_lookup(const struct dentry *parent, const struct qstr *name,
+ int ci_lookup)
{
unsigned int hash = name->hash;
struct hlist_bl_head *b = d_hash(hash);
@@ -2312,8 +2332,13 @@ struct dentry *__d_lookup(const struct dentry *parent, const struct qstr *name)
if (d_unhashed(dentry))
goto next;
- if (!d_same_name(dentry, parent, name))
- goto next;
+ if (ci_lookup) {
+ if (!d_same_name_ci(dentry, parent, name))
+ goto next;
+ } else {
+ if (!d_same_name(dentry, parent, name))
+ goto next;
+ }
dentry->d_lockref.count++;
found = dentry;
@@ -2476,7 +2501,7 @@ struct dentry *d_alloc_parallel(struct dentry *parent,
rcu_read_lock();
seq = smp_load_acquire(&parent->d_inode->i_dir_seq) & ~1;
r_seq = read_seqbegin(&rename_lock);
- dentry = __d_lookup_rcu(parent, name, &d_seq);
+ dentry = __d_lookup_rcu(parent, name, &d_seq, 0);
if (unlikely(dentry)) {
if (!lockref_get_not_dead(&dentry->d_lockref)) {
rcu_read_unlock();
diff --git a/fs/namei.c b/fs/namei.c
index 135a9a4e676b..1ebe5e775a9a 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1540,6 +1540,7 @@ static int lookup_fast(struct nameidata *nd,
struct dentry *dentry, *parent = nd->path.dentry;
int status = 1;
int err;
+ int ci_lookup = (nd->flags & LOOKUP_CASEFOLD);
/*
* Rename seqlock is not required here because in the off chance
@@ -1549,7 +1550,7 @@ static int lookup_fast(struct nameidata *nd,
if (nd->flags & LOOKUP_RCU) {
unsigned seq;
bool negative;
- dentry = __d_lookup_rcu(parent, &nd->last, &seq);
+ dentry = __d_lookup_rcu(parent, &nd->last, &seq, ci_lookup);
if (unlikely(!dentry)) {
if (unlazy_walk(nd))
return -ECHILD;
@@ -1595,7 +1596,7 @@ static int lookup_fast(struct nameidata *nd,
/* we'd been told to redo it in non-rcu mode */
status = d_revalidate(dentry, nd->flags);
} else {
- dentry = __d_lookup(parent, &nd->last);
+ dentry = __d_lookup(parent, &nd->last, ci_lookup);
if (unlikely(!dentry))
return 0;
status = d_revalidate(dentry, nd->flags);
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index 82a99d366aec..a4ce5ea207ad 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -139,6 +139,8 @@ struct dentry_operations {
int (*d_hash)(const struct dentry *, struct qstr *);
int (*d_compare)(const struct dentry *,
unsigned int, const char *, const struct qstr *);
+ int (*d_compare_ci)(const struct dentry *,
+ unsigned int, const char *, const struct qstr *);
int (*d_delete)(const struct dentry *);
int (*d_init)(struct dentry *);
void (*d_release)(struct dentry *);
@@ -282,9 +284,11 @@ extern struct dentry *d_ancestor(struct dentry *, struct dentry *);
/* appendix may either be NULL or be used for transname suffixes */
extern struct dentry *d_lookup(const struct dentry *, const struct qstr *);
extern struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *);
-extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *);
+extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *,
+ int ci_lookup);
extern struct dentry *__d_lookup_rcu(const struct dentry *parent,
- const struct qstr *name, unsigned *seq);
+ const struct qstr *name, unsigned *seq,
+ int ci_lookup);
static inline unsigned d_count(const struct dentry *dentry)
{
--
2.17.0
