nfs: report the inode version in getattr if requested

Allow NFS to report the i_version in getattr requests. Since the cost to
fetch it is relatively cheap, do it unconditionally and just set the
flag if it looks like it's valid. Also, conditionally enable the
MONOTONIC flag when the server reports its change attr type as such.

Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jeff Layton <jlayton@kernel.org>

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index e98ee75..756ad4f 100644 (file)
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -825,6 +825,8 @@ static u32 nfs_get_valid_attrmask(struct inode *inode)
                reply_mask |= STATX_UID | STATX_GID;
        if (!(cache_validity & NFS_INO_INVALID_BLOCKS))
                reply_mask |= STATX_BLOCKS;
+       if (!(cache_validity & NFS_INO_INVALID_CHANGE))
+               reply_mask |= STATX_CHANGE_COOKIE;
        return reply_mask;
 }
 
@@ -843,7 +845,8 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 
        request_mask &= STATX_TYPE | STATX_MODE | STATX_NLINK | STATX_UID |
                        STATX_GID | STATX_ATIME | STATX_MTIME | STATX_CTIME |
-                       STATX_INO | STATX_SIZE | STATX_BLOCKS;
+                       STATX_INO | STATX_SIZE | STATX_BLOCKS | STATX_BTIME |
+                       STATX_CHANGE_COOKIE;
 
        if ((query_flags & AT_STATX_DONT_SYNC) && !force_sync) {
                if (readdirplus_enabled)
@@ -851,8 +854,8 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
                goto out_no_revalidate;
        }
 
-       /* Flush out writes to the server in order to update c/mtime.  */
-       if ((request_mask & (STATX_CTIME | STATX_MTIME)) &&
+       /* Flush out writes to the server in order to update c/mtime/version.  */
+       if ((request_mask & (STATX_CTIME | STATX_MTIME | STATX_CHANGE_COOKIE)) &&
            S_ISREG(inode->i_mode))
                filemap_write_and_wait(inode->i_mapping);
 
@@ -872,7 +875,8 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
        /* Is the user requesting attributes that might need revalidation? */
        if (!(request_mask & (STATX_MODE|STATX_NLINK|STATX_ATIME|STATX_CTIME|
                                        STATX_MTIME|STATX_UID|STATX_GID|
-                                       STATX_SIZE|STATX_BLOCKS)))
+                                       STATX_SIZE|STATX_BLOCKS|
+                                       STATX_CHANGE_COOKIE)))
                goto out_no_revalidate;
 
        /* Check whether the cached attributes are stale */
@@ -910,6 +914,10 @@ out_no_revalidate:
 
        generic_fillattr(&init_user_ns, inode, stat);
        stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
+       stat->change_cookie = inode_peek_iversion_raw(inode);
+       stat->attributes_mask |= STATX_ATTR_CHANGE_MONOTONIC;
+       if (server->change_attr_type != NFS4_CHANGE_TYPE_IS_UNDEFINED)
+               stat->attributes |= STATX_ATTR_CHANGE_MONOTONIC;
        if (S_ISDIR(inode->i_mode))
                stat->blksize = NFS_SERVER(inode)->dtsize;
 out: