[PATCH v6 1/2] fs/dcache: export d_same_name() helper

From: Xiubo Li
Date: Wed May 25 2022 - 21:17:59 EST


Compare dentry name with case-exact name, return true if names
are same, or false.

Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
---
fs/dcache.c | 15 +++++++++++----
include/linux/dcache.h | 2 ++
2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/fs/dcache.c b/fs/dcache.c
index 93f4f5ee07bf..a409312ee0df 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2247,10 +2247,16 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
}
EXPORT_SYMBOL(d_add_ci);

-
-static inline bool d_same_name(const struct dentry *dentry,
- const struct dentry *parent,
- const struct qstr *name)
+/**
+ * d_same_name - compare dentry name with case-exact name
+ * @parent: parent dentry
+ * @dentry: the negative dentry that was passed to the parent's lookup func
+ * @name: the case-exact name to be associated with the returned dentry
+ *
+ * Return: true if names are same, or false
+ */
+bool d_same_name(const struct dentry *dentry, const struct dentry *parent,
+ const struct qstr *name)
{
if (likely(!(parent->d_flags & DCACHE_OP_COMPARE))) {
if (dentry->d_name.len != name->len)
@@ -2261,6 +2267,7 @@ static inline bool d_same_name(const struct dentry *dentry,
dentry->d_name.len, dentry->d_name.name,
name) == 0;
}
+EXPORT_SYMBOL_GPL(d_same_name);

/**
* __d_lookup_rcu - search for a dentry (racy, store-free)
diff --git a/include/linux/dcache.h b/include/linux/dcache.h
index f5bba51480b2..bb72361834de 100644
--- a/include/linux/dcache.h
+++ b/include/linux/dcache.h
@@ -233,6 +233,8 @@ extern struct dentry * d_alloc_parallel(struct dentry *, const struct qstr *,
wait_queue_head_t *);
extern struct dentry * d_splice_alias(struct inode *, struct dentry *);
extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *);
+extern bool d_same_name(const struct dentry *dentry, const struct dentry *parent,
+ const struct qstr *name);
extern struct dentry * d_exact_alias(struct dentry *, struct inode *);
extern struct dentry *d_find_any_alias(struct inode *inode);
extern struct dentry * d_obtain_alias(struct inode *);
--
2.36.0.rc1