Ian Kent <raven@xxxxxxxxxx> writes:
> While the dentry operation kernfs_dop_revalidate() is grouped with
> dentry type functions it also has a strong affinity to the inode
> operation ->lookup().
>
> In order to take advantage of the VFS negative dentry caching that
> can be used to reduce path lookup overhead on non-existent paths it
> will need to call kernfs_find_ns(). So, to avoid a forward declaration,
> move it to be near kernfs_iop_lookup().
>
> There's no functional change from this patch.
Does this patch compile independently?
During the code movement kernfs_active is replaced
by kernfs_active_read which does not exist yet.
Eric
> 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 7e0e62deab53c..4c69e2af82dac 100644
> --- a/fs/kernfs/dir.c
> +++ b/fs/kernfs/dir.c
> @@ -548,49 +548,6 @@ 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);
> - mutex_lock(&kernfs_mutex);
> -
> - /* The kernfs node has been deactivated */
> - if (!kernfs_active(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;
> -
> - mutex_unlock(&kernfs_mutex);
> - return 1;
> -out_bad:
> - mutex_unlock(&kernfs_mutex);
> -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
> @@ -1073,6 +1030,49 @@ 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);
> + mutex_lock(&kernfs_mutex);
> +
> + /* 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;
> +
> + mutex_unlock(&kernfs_mutex);
> + return 1;
> +out_bad:
> + mutex_unlock(&kernfs_mutex);
> +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)
