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Diffstat (limited to 'fs/kernfs/dir.c')
-rw-r--r--fs/kernfs/dir.c55
1 files changed, 35 insertions, 20 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index b3d1bc0f317d..0b21a8f961ac 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -1039,9 +1039,31 @@ static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
if (flags & LOOKUP_RCU)
return -ECHILD;
- /* Always perform fresh lookup for negatives */
- if (d_really_is_negative(dentry))
- goto out_bad_unlocked;
+ /* Negative hashed dentry? */
+ if (d_really_is_negative(dentry)) {
+ struct kernfs_node *parent;
+
+ /* If the kernfs parent node has changed discard and
+ * proceed to ->lookup.
+ */
+ mutex_lock(&kernfs_mutex);
+ spin_lock(&dentry->d_lock);
+ parent = kernfs_dentry_node(dentry->d_parent);
+ if (parent) {
+ if (kernfs_dir_changed(parent, dentry)) {
+ spin_unlock(&dentry->d_lock);
+ mutex_unlock(&kernfs_mutex);
+ return 0;
+ }
+ }
+ spin_unlock(&dentry->d_lock);
+ mutex_unlock(&kernfs_mutex);
+
+ /* The kernfs parent node hasn't changed, leave the
+ * dentry negative and return success.
+ */
+ return 1;
+ }
kn = kernfs_dentry_node(dentry);
mutex_lock(&kernfs_mutex);
@@ -1067,7 +1089,6 @@ static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
return 1;
out_bad:
mutex_unlock(&kernfs_mutex);
-out_bad_unlocked:
return 0;
}
@@ -1082,33 +1103,27 @@ static struct dentry *kernfs_iop_lookup(struct inode *dir,
struct dentry *ret;
struct kernfs_node *parent = dir->i_private;
struct kernfs_node *kn;
- struct inode *inode;
+ struct inode *inode = NULL;
const void *ns = NULL;
mutex_lock(&kernfs_mutex);
-
if (kernfs_ns_enabled(parent))
ns = kernfs_info(dir->i_sb)->ns;
kn = kernfs_find_ns(parent, dentry->d_name.name, ns);
-
- /* no such entry */
- if (!kn || !kernfs_active(kn)) {
- ret = NULL;
- goto out_unlock;
- }
-
/* attach dentry and inode */
- inode = kernfs_get_inode(dir->i_sb, kn);
- if (!inode) {
- ret = ERR_PTR(-ENOMEM);
- goto out_unlock;
+ if (kn && kernfs_active(kn)) {
+ inode = kernfs_get_inode(dir->i_sb, kn);
+ if (!inode)
+ inode = ERR_PTR(-ENOMEM);
}
-
- /* instantiate and hash dentry */
+ /* Needed only for negative dentry validation */
+ if (!inode)
+ kernfs_set_rev(parent, dentry);
+ /* instantiate and hash (possibly negative) dentry */
ret = d_splice_alias(inode, dentry);
- out_unlock:
mutex_unlock(&kernfs_mutex);
+
return ret;
}