linux/fs/afs/afs_fs.h

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/* AFS File Service definitions
*
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef AFS_FS_H
#define AFS_FS_H
#define AFS_FS_PORT 7000 /* AFS file server port */
#define FS_SERVICE 1 /* AFS File Service ID */
enum AFS_FS_Operations {
FSFETCHDATA = 130, /* AFS Fetch file data */
FSFETCHSTATUS = 132, /* AFS Fetch file status */
FSSTOREDATA = 133, /* AFS Store file data */
FSSTORESTATUS = 135, /* AFS Store file status */
FSREMOVEFILE = 136, /* AFS Remove a file */
FSCREATEFILE = 137, /* AFS Create a file */
FSRENAME = 138, /* AFS Rename or move a file or directory */
FSSYMLINK = 139, /* AFS Create a symbolic link */
FSLINK = 140, /* AFS Create a hard link */
FSMAKEDIR = 141, /* AFS Create a directory */
FSREMOVEDIR = 142, /* AFS Remove a directory */
FSGIVEUPCALLBACKS = 147, /* AFS Discard callback promises */
FSGETVOLUMEINFO = 148, /* AFS Get information about a volume */
FSGETVOLUMESTATUS = 149, /* AFS Get volume status information */
FSGETROOTVOLUME = 151, /* AFS Get root volume name */
FSSETLOCK = 156, /* AFS Request a file lock */
FSEXTENDLOCK = 157, /* AFS Extend a file lock */
FSRELEASELOCK = 158, /* AFS Release a file lock */
FSLOOKUP = 161, /* AFS lookup file in directory */
FSFETCHDATA64 = 65537, /* AFS Fetch file data */
FSSTOREDATA64 = 65538, /* AFS Store file data */
afs: Overhaul the callback handling Overhaul the AFS callback handling by the following means: (1) Don't give up callback promises on vnodes that we are no longer using, rather let them just expire on the server or let the server break them. This is actually more efficient for the server as the callback lookup is expensive if there are lots of extant callbacks. (2) Only give up the callback promises we have from a server when the server record is destroyed. Then we can just give up *all* the callback promises on it in one go. (3) Servers can end up being shared between cells if cells are aliased, so don't add all the vnodes being backed by a particular server into a big FID-indexed tree on that server as there may be duplicates. Instead have each volume instance (~= superblock) register an interest in a server as it starts to make use of it and use this to allow the processor for callbacks from the server to find the superblock and thence the inode corresponding to the FID being broken by means of ilookup_nowait(). (4) Rather than iterating over the entire callback list when a mass-break comes in from the server, maintain a counter of mass-breaks in afs_server (cb_seq) and make afs_validate() check it against the copy in afs_vnode. It would be nice not to have to take a read_lock whilst doing this, but that's tricky without using RCU. (5) Save a ref on the fileserver we're using for a call in the afs_call struct so that we can access its cb_s_break during call decoding. (6) Write-lock around callback and status storage in a vnode and read-lock around getattr so that we don't see the status mid-update. This has the following consequences: (1) Data invalidation isn't seen until someone calls afs_validate() on a vnode. Unfortunately, we need to use a key to query the server, but getting one from a background thread is tricky without caching loads of keys all over the place. (2) Mass invalidation isn't seen until someone calls afs_validate(). (3) Callback breaking is going to hit the inode_hash_lock quite a bit. Could this be replaced with rcu_read_lock() since inodes are destroyed under RCU conditions. Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 15:27:49 +00:00
FSGIVEUPALLCALLBACKS = 65539, /* AFS Give up all outstanding callbacks on a server */
};
enum AFS_FS_Errors {
VRESTARTING = -100, /* Server is restarting */
VSALVAGE = 101, /* volume needs salvaging */
VNOVNODE = 102, /* no such file/dir (vnode) */
VNOVOL = 103, /* no such volume or volume unavailable */
VVOLEXISTS = 104, /* volume name already exists */
VNOSERVICE = 105, /* volume not currently in service */
VOFFLINE = 106, /* volume is currently offline (more info available [VVL-spec]) */
VONLINE = 107, /* volume is already online */
VDISKFULL = 108, /* disk partition is full */
VOVERQUOTA = 109, /* volume's maximum quota exceeded */
VBUSY = 110, /* volume is temporarily unavailable */
VMOVED = 111, /* volume moved to new server - ask this FS where */
VIO = 112, /* I/O error in volume */
VSALVAGING = 113, /* Volume is being salvaged */
VRESTRICTED = 120, /* Volume is restricted from using */
};
#endif /* AFS_FS_H */