On Sun, Dec 01, 2024 at 02:12:25PM +0100, Christian Brauner wrote:
> Some filesystems like kernfs and pidfs support file handles as a
> convenience to use name_to_handle_at(2) and open_by_handle_at(2) but
> don't want to and cannot be reliably exported. Add a flag that allows
> them to mark their export operations accordingly.
>
> Fixes: aa8188253474 ("kernfs: add exportfs operations")
> Cc: stable <stable@xxxxxxxxxx> # >= 4.14
> Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
> ---
> fs/nfsd/export.c | 8 +++++++-
> include/linux/exportfs.h | 1 +
> 2 files changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
> index eacafe46e3b673cb306bd3c7caabd3283a1e54b1..786551595cc1c2043e8c195c00ca72ef93c769d6 100644
> --- a/fs/nfsd/export.c
> +++ b/fs/nfsd/export.c
> @@ -417,6 +417,7 @@ static struct svc_export *svc_export_lookup(struct svc_export *);
> static int check_export(struct path *path, int *flags, unsigned char *uuid)
> {
> struct inode *inode = d_inode(path->dentry);
> + const struct export_operations *nop;
>
> /*
> * We currently export only dirs, regular files, and (for v4
> @@ -449,11 +450,16 @@ static int check_export(struct path *path, int *flags, unsigned char *uuid)
> return -EINVAL;
> }
>
> - if (!exportfs_can_decode_fh(inode->i_sb->s_export_op)) {
> + if (!exportfs_can_decode_fh(nop)) {
Where is nop initialised?
> dprintk("exp_export: export of invalid fs type.\n");
> return -EINVAL;
> }
>
> + if (nop && nop->flags & EXPORT_OP_LOCAL_FILE_HANDLE) {
Also, please use () around & operations so we can understand that
this is not an accidental typo. i.e:
if (nop && (nop->flags & EXPORT_OP_LOCAL_FILE_HANDLE)) {
clearly expresses the intent of the code, and now it is obviously
correct at a glance.
-Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
