1*229bf1afSpooka.\" $NetBSD: puffs_flush.3,v 1.8 2009/02/20 14:26:56 pooka Exp $ 2809ae5f8Spooka.\" 3809ae5f8Spooka.\" Copyright (c) 2007 Antti Kantee. All rights reserved. 4809ae5f8Spooka.\" 5809ae5f8Spooka.\" Redistribution and use in source and binary forms, with or without 6809ae5f8Spooka.\" modification, are permitted provided that the following conditions 7809ae5f8Spooka.\" are met: 8809ae5f8Spooka.\" 1. Redistributions of source code must retain the above copyright 9809ae5f8Spooka.\" notice, this list of conditions and the following disclaimer. 10809ae5f8Spooka.\" 2. Redistributions in binary form must reproduce the above copyright 11809ae5f8Spooka.\" notice, this list of conditions and the following disclaimer in the 12809ae5f8Spooka.\" documentation and/or other materials provided with the distribution. 13809ae5f8Spooka.\" 14809ae5f8Spooka.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15809ae5f8Spooka.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16809ae5f8Spooka.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17809ae5f8Spooka.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18809ae5f8Spooka.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19809ae5f8Spooka.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20809ae5f8Spooka.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21809ae5f8Spooka.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22809ae5f8Spooka.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23809ae5f8Spooka.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24809ae5f8Spooka.\" SUCH DAMAGE. 25809ae5f8Spooka.\" 26622f8591Spooka.Dd April 7, 2007 27809ae5f8Spooka.Dt PUFFS_FLUSH 3 28809ae5f8Spooka.Os 29809ae5f8Spooka.Sh NAME 30809ae5f8Spooka.Nm puffs_flush 31809ae5f8Spooka.Nd puffs kernel cache flushing and invalidation routines 32809ae5f8Spooka.Sh LIBRARY 33809ae5f8Spooka.Lb libpuffs 34809ae5f8Spooka.Sh SYNOPSIS 35809ae5f8Spooka.In puffs.h 36809ae5f8Spooka.Ft int 37ff423327Spooka.Fo puffs_inval_namecache_dir 38ff423327Spooka.Fa "struct puffs_usermount *pu" "puffs_cookie_t cookie" 39ff423327Spooka.Fc 40809ae5f8Spooka.Ft int 41809ae5f8Spooka.Fn puffs_inval_namecache_all "struct puffs_usermount *pu" 42622f8591Spooka.Ft int 43ff423327Spooka.Fo puffs_inval_pagecache_node 44ff423327Spooka.Fa "struct puffs_usermount *pu" "puffs_cookie_t cookie" 45622f8591Spooka.Fc 46f7d8f113Spooka.Ft int 47ff423327Spooka.Fo puffs_inval_pagecache_node_range 48ff423327Spooka.Fa "struct puffs_usermount *pu" "puffs_cookie_t cookie" "off_t start" 49ff423327Spooka.Fa "off_t end" 50ff423327Spooka.Fc 51ff423327Spooka.Ft int 52ff423327Spooka.Fo puffs_flush_pagecache_node 53ff423327Spooka.Fa "struct puffs_usermount *pu" "puffs_cookie_t cookie" 54ff423327Spooka.Fc 55f7d8f113Spooka.Ft int 56f7d8f113Spooka.Fo puffs_flush_pagecache_node_range 57ff423327Spooka.Fa "struct puffs_usermount *pu" "puffs_cookie_t cookie" "off_t start" 58ff423327Spooka.Fa "off_t end" 59f7d8f113Spooka.Fc 60809ae5f8Spooka.Sh DESCRIPTION 61809ae5f8SpookaThese routines are used inform the kernel that any information it might 62809ae5f8Spookahave cached is no longer valid. 63809ae5f8Spooka.Fn puffs_inval_namecache_dir 64809ae5f8Spookainvalidates the name cache for a given directory. 65809ae5f8SpookaThe argument 66809ae5f8Spooka.Va cookie 67809ae5f8Spookashould describe an existing and valid directory cookie for the file 68809ae5f8Spookasystem. 69809ae5f8SpookaSimilarly, 70809ae5f8Spooka.Fn puffs_inval_namecache_all 71809ae5f8Spookainvalidates the name cache for the entire file system 72809ae5f8Spooka(this routine might go away). 73622f8591Spooka.Pp 74622f8591SpookaThe cached pages (file contents) for a regular file described by 75622f8591Spooka.Va cookie 76622f8591Spookaare invalidated using 77622f8591Spooka.Fn puffs_inval_pagecache_node . 78622f8591SpookaA specific range can be invalidated using 79622f8591Spooka.Fn puffs_inval_pagecache_node_range 80622f8591Spookafor a platform specific page level granularity. 81622f8591SpookaThe offset 82622f8591Spooka.Va start 83622f8591Spookawill be 84622f8591Spooka.Em truncated 85622f8591Spookato a page boundary while 86622f8591Spooka.Va end 87622f8591Spookawill be 88622f8591Spooka.Em "rounded up" 89622f8591Spookato the next page boundary. 90622f8591SpookaAs a special case, specifying 0 as 91622f8591Spooka.Va end 92622f8591Spookawill invalidate all contents from 93622f8591Spooka.Va start 94622f8591Spookato the end of the file. 95622f8591Spooka.Pp 96622f8591SpookaIt is especially important to note that these routines will not only 97622f8591Spookainvalidate data in the "read cache", but also data in the "write back" 98622f8591Spookacache (conceptually speaking; in reality they are the same cache), which 99622f8591Spookahas not yet been flushed to the file server. 100622f8591SpookaTherefore any unflushed data will be lost. 101f7d8f113Spooka.Pp 102f7d8f113SpookaThe counterparts of the invalidation routines are the flushing routines 103f7d8f113Spooka.Fn puffs_flush_pagecache_node 104f7d8f113Spookaand 105f7d8f113Spooka.Fn puffs_flush_pagecache_node_range , 106f7d8f113Spookawhich force unwritten data from the kernel page cache to be written. 107f7d8f113SpookaFor the flush range version, the same range rules as with the 108f7d8f113Spookainvalidation routine apply. 109f7d8f113SpookaThe data is flushed asynchronously, i.e. if the routine returns 1109429ef03Swizsuccessfully, all the caller knows is that the data has been queued 111f7d8f113Spookafor writing. 112809ae5f8Spooka.Sh SEE ALSO 113809ae5f8Spooka.Xr puffs 3 114