This prevents a soft hang if called d_add_ci is called from the FS
layer, when doing a CI search but the result dentry is the exact match.
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxxxx>
---
fs/dcache.c | 33 ++++++++++++++++++---------------
1 file changed, 18 insertions(+), 15 deletions(-)
diff --git a/fs/dcache.c b/fs/dcache.c
index 4bd28d7caa53..30c5eff31e88 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2049,6 +2049,20 @@ struct dentry *d_obtain_root(struct inode *inode)
}
EXPORT_SYMBOL(d_obtain_root);
+static inline 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)
+ return false;
+ return dentry_cmp(dentry, name->name, name->len) == 0;
+ }
+ return parent->d_op->d_compare(dentry,
+ dentry->d_name.len, dentry->d_name.name,
+ name) == 0;
+}
+
static inline bool d_same_name_ci(const struct dentry *dentry,
const struct dentry *parent,
const struct qstr *name)
@@ -2080,6 +2094,10 @@ struct dentry *d_add_ci(struct dentry *dentry, struct inode *inode,
{
struct dentry *found, *res;
+ /* Trivial case: CI search is exact match. */
+ if (d_same_name(dentry, dentry->d_parent, name))
+ return d_splice_alias(inode, dentry);
+
/*
* First check if a dentry matching the name already exists,
* if not go ahead and create it now.
@@ -2112,21 +2130,6 @@ 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)
-{
- if (likely(!(parent->d_flags & DCACHE_OP_COMPARE))) {
- if (dentry->d_name.len != name->len)
- return false;
- return dentry_cmp(dentry, name->name, name->len) == 0;
- }
- return parent->d_op->d_compare(dentry,
- dentry->d_name.len, dentry->d_name.name,
- name) == 0;
-}
-
/**
* __d_lookup_rcu - search for a dentry (racy, store-free)
* @parent: parent dentry
--
2.17.0
