fs/afs/validation.c

2 /* vnode and volume validity verification.
19  *  (2) On a RW volume, in response to certain vnode (inode)-accessing RPC
20  *      calls, the server maintains a time-limited per-vnode promise that it
24  *      Note that a vnode-level callbacks may also be sent for other reasons,
27  *  (3) On a RO (or Backup) volume, in response to certain vnode-accessing RPC
50  *	a volume have been altered since we last checked a vnode.
63  *      vnode have been altered.
78  *  (3) When a vnode-level CB.CallBack occurs, we increment ->cb_break on the
79  *	vnode and reset its ->cb_expires_at.  If the vnode is mmapped, we also
80  *	dispatch a work item to unmap all PTEs to the vnode's pagecache to
84  *	validity of a vnode.  This first checks to see if ->cb_v_check and
86  *	exclusively and perform an FS.FetchStatus on the vnode.
88  *	After checking the volume, we check the vnode.  If there's a mismatch
89  *	between the volume counters and the vnode's mirrors of those counters,
90  *	we lock vnode->validate_lock and issue an FS.FetchStatus on the vnode.
110  *	parsed and used to set the promise in ->cb_expires_at for the vnode,
114  *      the vnode.
118  * Check the validity of a vnode/inode and its parent volume.
120 bool afs_check_validity(const struct afs_vnode *vnode)
122 	const struct afs_volume *volume = vnode->volume;
125 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
129 	    atomic64_read(&vnode->cb_expires_at)  <= deadline ||
131 	    vnode->cb_ro_snapshot != atomic_read(&volume->cb_ro_snapshot) ||
132 	    vnode->cb_scrub	  != atomic_read(&volume->cb_scrub) ||
133 	    test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
358 static void afs_zap_data(struct afs_vnode *vnode)
360 	_enter("{%llx:%llu}", vnode->fid.vid, vnode->fid.vnode);
362 	afs_invalidate_cache(vnode, 0);
367 	if (S_ISREG(vnode->netfs.inode.i_mode))
368 		invalidate_remote_inode(&vnode->netfs.inode);
370 		invalidate_inode_pages2(vnode->netfs.inode.i_mapping);
374  * validate a vnode/inode
382 int afs_validate(struct afs_vnode *vnode, struct key *key)
384 	struct afs_volume *volume = vnode->volume;
391 	       vnode->fid.vid, vnode->fid.vnode, vnode->flags,
394 	if (afs_check_validity(vnode))
395 		return test_bit(AFS_VNODE_DELETED, &vnode->flags) ? -ESTALE : 0;
397 	ret = down_write_killable(&vnode->validate_lock);
401 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
421 	if (vnode->cb_ro_snapshot != cb_ro_snapshot ||
422 	    vnode->cb_scrub	  != cb_scrub)
423 		unmap_mapping_pages(vnode->netfs.inode.i_mapping, 0, 0, false);
425 	if (vnode->cb_ro_snapshot != cb_ro_snapshot ||
426 	    vnode->cb_scrub	  != cb_scrub ||
429 	    atomic64_read(&vnode->cb_expires_at) <= deadline
431 		ret = afs_fetch_status(vnode, key, false, NULL);
434 				set_bit(AFS_VNODE_DELETED, &vnode->flags);
440 		_debug("new promise [fl=%lx]", vnode->flags);
451 	_debug("vnode inval %x==%x %x==%x",
452 	       vnode->cb_ro_snapshot, cb_ro_snapshot,
453 	       vnode->cb_scrub, cb_scrub);
454 	if (vnode->cb_scrub != cb_scrub)
456 	vnode->cb_ro_snapshot = cb_ro_snapshot;
457 	vnode->cb_scrub = cb_scrub;
459 	/* if the vnode's data version number changed then its contents are
461 	zap |= test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags);
463 		afs_zap_data(vnode);
464 	up_write(&vnode->validate_lock);
471 	up_write(&vnode->validate_lock);