On Mon, 2020-11-16 at 22:18 -0500, J. Bruce Fields wrote:
> From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
>
> The i_version on NFS has pretty much opaque to the client, so we don't
> want to give the low bit any special interpretation.
>
> Define a new FS_PRIVATE_I_VERSION flag for filesystems that manage the
> i_version on their own.
>
Description here doesn't quite match the patch...
> Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
> ---
> fs/nfs/export.c | 1 +
> include/linux/exportfs.h | 1 +
> include/linux/iversion.h | 4 ++++
> 3 files changed, 6 insertions(+)
>
> diff --git a/fs/nfs/export.c b/fs/nfs/export.c
> index 3430d6891e89..c2eb915a54ca 100644
> --- a/fs/nfs/export.c
> +++ b/fs/nfs/export.c
> @@ -171,4 +171,5 @@ const struct export_operations nfs_export_ops = {
> .encode_fh = nfs_encode_fh,
> .fh_to_dentry = nfs_fh_to_dentry,
> .get_parent = nfs_get_parent,
> + .fetch_iversion = inode_peek_iversion_raw,
> };
> diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h
> index 3ceb72b67a7a..6000121a201f 100644
> --- a/include/linux/exportfs.h
> +++ b/include/linux/exportfs.h
> @@ -213,6 +213,7 @@ struct export_operations {
> bool write, u32 *device_generation);
> int (*commit_blocks)(struct inode *inode, struct iomap *iomaps,
> int nr_iomaps, struct iattr *iattr);
> + u64 (*fetch_iversion)(const struct inode *);
> };
>
>
>
>
>
>
>
>
> extern int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid,
> diff --git a/include/linux/iversion.h b/include/linux/iversion.h
> index 2917ef990d43..481b3debf6bb 100644
> --- a/include/linux/iversion.h
> +++ b/include/linux/iversion.h
> @@ -3,6 +3,7 @@
> #define _LINUX_IVERSION_H
>
>
>
>
>
>
>
>
> #include <linux/fs.h>
> +#include <linux/exportfs.h>
>
>
>
>
>
>
>
>
> /*
> * The inode->i_version field:
> @@ -306,6 +307,9 @@ inode_query_iversion(struct inode *inode)
> {
> u64 cur, old, new;
>
>
>
>
>
>
>
>
> + if (inode->i_sb->s_export_op->fetch_iversion)
> + return inode->i_sb->s_export_op->fetch_iversion(inode);
> +
This looks dangerous -- s_export_op could be a NULL pointer.
> cur = inode_peek_iversion_raw(inode);
> for (;;) {
> /* If flag is already set, then no need to swap */
--
Jeff Layton <jlayton@xxxxxxxxxx>
