From 3cc55f4434b421d37300aa9a167ace7d60b45ccf Mon Sep 17 00:00:00 2001 From: J. Bruce Fields Date: Fri, 29 Jan 2021 14:26:29 -0500 Subject: nfs: use change attribute for NFS re-exports When exporting NFS, we may as well use the real change attribute returned by the original server instead of faking up a change attribute from the ctime. Note we can't do that by setting I_VERSION--that would also turn on the logic in iversion.h which treats the lower bit specially, and that doesn't make sense for NFS. So instead we define a new export operation for filesystems like NFS that want to manage the change attribute themselves. Signed-off-by: J. Bruce Fields Reviewed-by: Christoph Hellwig Signed-off-by: Chuck Lever --- fs/nfs/export.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'fs/nfs') diff --git a/fs/nfs/export.c b/fs/nfs/export.c index 7412bb164fa7..f2b34cfe286c 100644 --- a/fs/nfs/export.c +++ b/fs/nfs/export.c @@ -167,10 +167,28 @@ out: return parent; } +static u64 nfs_fetch_iversion(struct inode *inode) +{ + struct nfs_server *server = NFS_SERVER(inode); + + /* Is this the right call?: */ + nfs_revalidate_inode(server, inode); + /* + * Also, note we're ignoring any returned error. That seems to be + * the practice for cache consistency information elsewhere in + * the server, but I'm not sure why. + */ + if (server->nfs_client->rpc_ops->version >= 4) + return inode_peek_iversion_raw(inode); + else + return time_to_chattr(&inode->i_ctime); +} + 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 = nfs_fetch_iversion, .flags = EXPORT_OP_NOWCC|EXPORT_OP_NOSUBTREECHK| EXPORT_OP_CLOSE_BEFORE_UNLINK|EXPORT_OP_REMOTE_FS| EXPORT_OP_NOATOMIC_ATTR, -- cgit v1.2.3