afs: Rearrange status mapping

Rearrange the AFSFetchStatus to inode attribute mapping code in a number of
ways:

 (1) Use an XDR structure rather than a series of incremented pointer
     accesses when decoding an AFSFetchStatus object.  This allows
     out-of-order decode.

 (2) Don't store the if_version value but rather just check it and abort if
     it's not something we can handle.

 (3) Store the owner and group in the status record as raw values rather
     than converting them to kuid/kgid.  Do that when they're mapped into
     i_uid/i_gid.

 (4) Validate the type and abort code up front and abort if they're wrong.

 (5) Split the inode attribute setting out into its own function from the
     XDR decode of an AFSFetchStatus object.  This allows it to be called
     from elsewhere too.

 (6) Differentiate changes to data from changes to metadata.

 (7) Use the split-out attribute mapping function from afs_iget().

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 7 insertions, 16 deletions

diff --git a/fs/afs/inode.c b/fs/afs/inode.c
index 488abd78dc26..2e32d475ec11 100644
--- a/fs/afs/inode.c
+++ b/fs/afs/inode.c
@@ -30,12 +30,11 @@ static const struct inode_operations afs_symlink_inode_operations = {
 };
 
 /*
- * map the AFS file status to the inode member variables
+ * Initialise an inode from the vnode status.
  */
-static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
+static int afs_inode_init_from_status(struct afs_vnode *vnode, struct key *key)
 {
 	struct inode *inode = AFS_VNODE_TO_I(vnode);
-	bool changed;
 
 	_debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
 	       vnode->status.type,
@@ -46,6 +45,9 @@ static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
 
 	read_seqlock_excl(&vnode->cb_lock);
 
+	afs_update_inode_from_status(vnode, &vnode->status, NULL,
+				     AFS_VNODE_NOT_YET_SET);
+
 	switch (vnode->status.type) {
 	case AFS_FTYPE_FILE:
 		inode->i_mode	= S_IFREG | vnode->status.mode;
@@ -79,24 +81,13 @@ static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
 		return -EBADMSG;
 	}
 
-	changed = (vnode->status.size != inode->i_size);
-
-	set_nlink(inode, vnode->status.nlink);
-	inode->i_uid		= vnode->status.owner;
-	inode->i_gid            = vnode->status.group;
-	inode->i_size		= vnode->status.size;
-	inode->i_ctime.tv_sec	= vnode->status.mtime_client;
-	inode->i_ctime.tv_nsec	= 0;
-	inode->i_atime		= inode->i_mtime = inode->i_ctime;
 	inode->i_blocks		= 0;
-	inode->i_generation	= vnode->fid.unique;
-	inode_set_iversion_raw(inode, vnode->status.data_version);
 	inode->i_mapping->a_ops	= &afs_fs_aops;
 
 	read_sequnlock_excl(&vnode->cb_lock);
 
 #ifdef CONFIG_AFS_FSCACHE
-	if (changed)
+	if (vnode->status.size > 0)
 		fscache_attr_changed(vnode->cache);
 #endif
 	return 0;
@@ -331,7 +322,7 @@ struct inode *afs_iget(struct super_block *sb, struct key *key,
 		vnode->cb_expires_at += ktime_get_real_seconds();
 	}
 
-	ret = afs_inode_map_status(vnode, key);
+	ret = afs_inode_init_from_status(vnode, key);
 	if (ret < 0)
 		goto bad_inode;