[PATCH 2/4] kernfs: move revalidate to be near lookup

From: Ian Kent
Date: Mon May 25 2020 - 01:47:22 EST


While the dentry operation kernfs_dop_revalidate() is grouped with
dentry'ish functions it also has a strong afinity to the inode
operation ->lookup(). And when path walk improvements are applied
it will need to call kernfs_find_ns() so move it to be near
kernfs_iop_lookup() to avoid the need for a forward declaration.

There's no functional change from this patch.

Signed-off-by: Ian Kent <raven@xxxxxxxxxx>
---
fs/kernfs/dir.c | 86 ++++++++++++++++++++++++++++---------------------------
1 file changed, 43 insertions(+), 43 deletions(-)

diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index d8213fc65eba..9b315f3b20ee 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -559,49 +559,6 @@ void kernfs_put(struct kernfs_node *kn)
}
EXPORT_SYMBOL_GPL(kernfs_put);

-static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
-{
- struct kernfs_node *kn;
-
- if (flags & LOOKUP_RCU)
- return -ECHILD;
-
- /* Always perform fresh lookup for negatives */
- if (d_really_is_negative(dentry))
- goto out_bad_unlocked;
-
- kn = kernfs_dentry_node(dentry);
- down_read(&kernfs_rwsem);
-
- /* The kernfs node has been deactivated */
- if (!kernfs_active_read(kn))
- goto out_bad;
-
- /* The kernfs node has been moved? */
- if (kernfs_dentry_node(dentry->d_parent) != kn->parent)
- goto out_bad;
-
- /* The kernfs node has been renamed */
- if (strcmp(dentry->d_name.name, kn->name) != 0)
- goto out_bad;
-
- /* The kernfs node has been moved to a different namespace */
- if (kn->parent && kernfs_ns_enabled(kn->parent) &&
- kernfs_info(dentry->d_sb)->ns != kn->ns)
- goto out_bad;
-
- up_read(&kernfs_rwsem);
- return 1;
-out_bad:
- up_read(&kernfs_rwsem);
-out_bad_unlocked:
- return 0;
-}
-
-const struct dentry_operations kernfs_dops = {
- .d_revalidate = kernfs_dop_revalidate,
-};
-
/**
* kernfs_node_from_dentry - determine kernfs_node associated with a dentry
* @dentry: the dentry in question
@@ -1085,6 +1042,49 @@ struct kernfs_node *kernfs_create_empty_dir(struct kernfs_node *parent,
return ERR_PTR(rc);
}

+static int kernfs_dop_revalidate(struct dentry *dentry, unsigned int flags)
+{
+ struct kernfs_node *kn;
+
+ if (flags & LOOKUP_RCU)
+ return -ECHILD;
+
+ /* Always perform fresh lookup for negatives */
+ if (d_really_is_negative(dentry))
+ goto out_bad_unlocked;
+
+ kn = kernfs_dentry_node(dentry);
+ down_read(&kernfs_rwsem);
+
+ /* The kernfs node has been deactivated */
+ if (!kernfs_active_read(kn))
+ goto out_bad;
+
+ /* The kernfs node has been moved? */
+ if (kernfs_dentry_node(dentry->d_parent) != kn->parent)
+ goto out_bad;
+
+ /* The kernfs node has been renamed */
+ if (strcmp(dentry->d_name.name, kn->name) != 0)
+ goto out_bad;
+
+ /* The kernfs node has been moved to a different namespace */
+ if (kn->parent && kernfs_ns_enabled(kn->parent) &&
+ kernfs_info(dentry->d_sb)->ns != kn->ns)
+ goto out_bad;
+
+ up_read(&kernfs_rwsem);
+ return 1;
+out_bad:
+ up_read(&kernfs_rwsem);
+out_bad_unlocked:
+ return 0;
+}
+
+const struct dentry_operations kernfs_dops = {
+ .d_revalidate = kernfs_dop_revalidate,
+};
+
static struct dentry *kernfs_iop_lookup(struct inode *dir,
struct dentry *dentry,
unsigned int flags)