2007-04-27 06:57:07 +08:00
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/* AFS security handling
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*
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
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* Copyright (C) 2007, 2017 Red Hat, Inc. All Rights Reserved.
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2007-04-27 06:57:07 +08:00
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/fs.h>
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#include <linux/ctype.h>
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Detach sched.h from mm.h
First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.
This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
getting them indirectly
Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
they don't need sched.h
b) sched.h stops being dependency for significant number of files:
on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
after patch it's only 3744 (-8.3%).
Cross-compile tested on
all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
alpha alpha-up
arm
i386 i386-up i386-defconfig i386-allnoconfig
ia64 ia64-up
m68k
mips
parisc parisc-up
powerpc powerpc-up
s390 s390-up
sparc sparc-up
sparc64 sparc64-up
um-x86_64
x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig
as well as my two usual configs.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-21 05:22:52 +08:00
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#include <linux/sched.h>
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
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#include <linux/hashtable.h>
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2007-04-27 06:57:07 +08:00
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#include <keys/rxrpc-type.h>
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#include "internal.h"
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|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
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static DEFINE_HASHTABLE(afs_permits_cache, 10);
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static DEFINE_SPINLOCK(afs_permits_lock);
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2007-04-27 06:57:07 +08:00
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/*
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* get a key
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*/
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struct key *afs_request_key(struct afs_cell *cell)
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{
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struct key *key;
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_enter("{%x}", key_serial(cell->anonymous_key));
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_debug("key %s", cell->anonymous_key->description);
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key = request_key(&key_type_rxrpc, cell->anonymous_key->description,
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NULL);
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if (IS_ERR(key)) {
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if (PTR_ERR(key) != -ENOKEY) {
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_leave(" = %ld", PTR_ERR(key));
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return key;
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}
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/* act as anonymous user */
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_leave(" = {%x} [anon]", key_serial(cell->anonymous_key));
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return key_get(cell->anonymous_key);
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} else {
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/* act as authorised user */
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_leave(" = {%x} [auth]", key_serial(key));
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return key;
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}
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}
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/*
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
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* Dispose of a list of permits.
|
2007-04-27 06:57:07 +08:00
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*/
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
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static void afs_permits_rcu(struct rcu_head *rcu)
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2007-04-27 06:57:07 +08:00
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{
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struct afs_permits *permits =
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container_of(rcu, struct afs_permits, rcu);
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
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int i;
|
2007-04-27 06:57:07 +08:00
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
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for (i = 0; i < permits->nr_permits; i++)
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key_put(permits->permits[i].key);
|
2007-04-27 06:57:07 +08:00
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kfree(permits);
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}
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/*
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
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* Discard a permission cache.
|
2007-04-27 06:57:07 +08:00
|
|
|
*/
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
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void afs_put_permits(struct afs_permits *permits)
|
2007-04-27 06:57:07 +08:00
|
|
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{
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
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if (permits && refcount_dec_and_test(&permits->usage)) {
|
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spin_lock(&afs_permits_lock);
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hash_del_rcu(&permits->hash_node);
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spin_unlock(&afs_permits_lock);
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call_rcu(&permits->rcu, afs_permits_rcu);
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}
|
2007-04-27 06:57:07 +08:00
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}
|
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|
|
|
/*
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
* Clear a permit cache on callback break.
|
2007-04-27 06:57:07 +08:00
|
|
|
*/
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
void afs_clear_permits(struct afs_vnode *vnode)
|
2007-04-27 06:57:07 +08:00
|
|
|
{
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
struct afs_permits *permits;
|
2007-04-27 06:57:07 +08:00
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
spin_lock(&vnode->lock);
|
|
|
|
|
permits = rcu_dereference_protected(vnode->permit_cache,
|
|
|
|
|
lockdep_is_held(&vnode->lock));
|
|
|
|
|
RCU_INIT_POINTER(vnode->permit_cache, NULL);
|
|
|
|
|
vnode->cb_break++;
|
|
|
|
|
spin_unlock(&vnode->lock);
|
2007-04-27 06:57:07 +08:00
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
if (permits)
|
|
|
|
|
afs_put_permits(permits);
|
2007-04-27 06:57:07 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
* Hash a list of permits. Use simple addition to make it easy to add an extra
|
|
|
|
|
* one at an as-yet indeterminate position in the list.
|
2007-04-27 06:57:07 +08:00
|
|
|
*/
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
static void afs_hash_permits(struct afs_permits *permits)
|
2007-04-27 06:57:07 +08:00
|
|
|
{
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
unsigned long h = permits->nr_permits;
|
|
|
|
|
int i;
|
2007-04-27 06:57:07 +08:00
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
for (i = 0; i < permits->nr_permits; i++) {
|
|
|
|
|
h += (unsigned long)permits->permits[i].key / sizeof(void *);
|
|
|
|
|
h += permits->permits[i].access;
|
|
|
|
|
}
|
2007-04-27 06:57:07 +08:00
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
permits->h = h;
|
2007-04-27 06:57:07 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
* Cache the CallerAccess result obtained from doing a fileserver operation
|
|
|
|
|
* that returned a vnode status for a particular key. If a callback break
|
|
|
|
|
* occurs whilst the operation was in progress then we have to ditch the cache
|
|
|
|
|
* as the ACL *may* have changed.
|
2007-04-27 06:57:07 +08:00
|
|
|
*/
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
void afs_cache_permit(struct afs_vnode *vnode, struct key *key,
|
|
|
|
|
unsigned int cb_break)
|
2007-04-27 06:57:07 +08:00
|
|
|
{
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
struct afs_permits *permits, *xpermits, *replacement, *new = NULL;
|
|
|
|
|
afs_access_t caller_access = READ_ONCE(vnode->status.caller_access);
|
|
|
|
|
size_t size = 0;
|
|
|
|
|
bool changed = false;
|
|
|
|
|
int i, j;
|
|
|
|
|
|
|
|
|
|
_enter("{%x:%u},%x,%x",
|
|
|
|
|
vnode->fid.vid, vnode->fid.vnode, key_serial(key), caller_access);
|
|
|
|
|
|
|
|
|
|
rcu_read_lock();
|
|
|
|
|
|
|
|
|
|
/* Check for the common case first: We got back the same access as last
|
|
|
|
|
* time we tried and already have it recorded.
|
|
|
|
|
*/
|
|
|
|
|
permits = rcu_dereference(vnode->permit_cache);
|
|
|
|
|
if (permits) {
|
|
|
|
|
if (!permits->invalidated) {
|
|
|
|
|
for (i = 0; i < permits->nr_permits; i++) {
|
|
|
|
|
if (permits->permits[i].key < key)
|
|
|
|
|
continue;
|
|
|
|
|
if (permits->permits[i].key > key)
|
|
|
|
|
break;
|
|
|
|
|
if (permits->permits[i].access != caller_access) {
|
|
|
|
|
changed = true;
|
|
|
|
|
break;
|
|
|
|
|
}
|
2007-04-27 06:57:07 +08:00
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
if (cb_break != (vnode->cb_break +
|
|
|
|
|
vnode->cb_interest->server->cb_s_break)) {
|
|
|
|
|
changed = true;
|
|
|
|
|
break;
|
|
|
|
|
}
|
2007-04-27 06:57:07 +08:00
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
/* The cache is still good. */
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
}
|
2007-04-27 06:57:07 +08:00
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
changed |= permits->invalidated;
|
|
|
|
|
size = permits->nr_permits;
|
2007-04-27 06:57:07 +08:00
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
/* If this set of permits is now wrong, clear the permits
|
|
|
|
|
* pointer so that no one tries to use the stale information.
|
|
|
|
|
*/
|
|
|
|
|
if (changed) {
|
|
|
|
|
spin_lock(&vnode->lock);
|
|
|
|
|
if (permits != rcu_access_pointer(vnode->permit_cache))
|
|
|
|
|
goto someone_else_changed_it_unlock;
|
|
|
|
|
RCU_INIT_POINTER(vnode->permit_cache, NULL);
|
|
|
|
|
spin_unlock(&vnode->lock);
|
|
|
|
|
|
|
|
|
|
afs_put_permits(permits);
|
|
|
|
|
permits = NULL;
|
|
|
|
|
size = 0;
|
|
|
|
|
}
|
2007-04-27 06:57:07 +08:00
|
|
|
}
|
|
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
if (cb_break != (vnode->cb_break + vnode->cb_interest->server->cb_s_break)) {
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
goto someone_else_changed_it;
|
2007-04-27 06:57:07 +08:00
|
|
|
}
|
|
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
/* We need a ref on any permits list we want to copy as we'll have to
|
|
|
|
|
* drop the lock to do memory allocation.
|
|
|
|
|
*/
|
|
|
|
|
if (permits && !refcount_inc_not_zero(&permits->usage)) {
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
goto someone_else_changed_it;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
|
|
|
|
|
/* Speculatively create a new list with the revised permission set. We
|
|
|
|
|
* discard this if we find an extant match already in the hash, but
|
|
|
|
|
* it's easier to compare with memcmp this way.
|
|
|
|
|
*
|
|
|
|
|
* We fill in the key pointers at this time, but we don't get the refs
|
|
|
|
|
* yet.
|
|
|
|
|
*/
|
|
|
|
|
size++;
|
|
|
|
|
new = kzalloc(sizeof(struct afs_permits) +
|
|
|
|
|
sizeof(struct afs_permit) * size, GFP_NOFS);
|
|
|
|
|
if (!new)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
refcount_set(&new->usage, 1);
|
|
|
|
|
new->nr_permits = size;
|
|
|
|
|
i = j = 0;
|
|
|
|
|
if (permits) {
|
|
|
|
|
for (i = 0; i < permits->nr_permits; i++) {
|
|
|
|
|
if (j == i && permits->permits[i].key > key) {
|
|
|
|
|
new->permits[j].key = key;
|
|
|
|
|
new->permits[j].access = caller_access;
|
|
|
|
|
j++;
|
2007-04-27 06:57:07 +08:00
|
|
|
}
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
new->permits[j].key = permits->permits[i].key;
|
|
|
|
|
new->permits[j].access = permits->permits[i].access;
|
|
|
|
|
j++;
|
2007-04-27 06:57:07 +08:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
if (j == i) {
|
|
|
|
|
new->permits[j].key = key;
|
|
|
|
|
new->permits[j].access = caller_access;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
afs_hash_permits(new);
|
|
|
|
|
|
|
|
|
|
afs_put_permits(permits);
|
|
|
|
|
|
|
|
|
|
/* Now see if the permit list we want is actually already available */
|
|
|
|
|
spin_lock(&afs_permits_lock);
|
|
|
|
|
|
|
|
|
|
hash_for_each_possible(afs_permits_cache, xpermits, hash_node, new->h) {
|
|
|
|
|
if (xpermits->h != new->h ||
|
|
|
|
|
xpermits->invalidated ||
|
|
|
|
|
xpermits->nr_permits != new->nr_permits ||
|
|
|
|
|
memcmp(xpermits->permits, new->permits,
|
|
|
|
|
new->nr_permits * sizeof(struct afs_permit)) != 0)
|
|
|
|
|
continue;
|
|
|
|
|
|
|
|
|
|
if (refcount_inc_not_zero(&xpermits->usage)) {
|
|
|
|
|
replacement = xpermits;
|
|
|
|
|
goto found;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
break;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < new->nr_permits; i++)
|
|
|
|
|
key_get(new->permits[i].key);
|
|
|
|
|
hash_add_rcu(afs_permits_cache, &new->hash_node, new->h);
|
|
|
|
|
replacement = new;
|
|
|
|
|
new = NULL;
|
|
|
|
|
|
|
|
|
|
found:
|
|
|
|
|
spin_unlock(&afs_permits_lock);
|
|
|
|
|
|
|
|
|
|
kfree(new);
|
|
|
|
|
|
|
|
|
|
spin_lock(&vnode->lock);
|
|
|
|
|
if (cb_break != (vnode->cb_break + vnode->cb_interest->server->cb_s_break) ||
|
|
|
|
|
permits != rcu_access_pointer(vnode->permit_cache))
|
|
|
|
|
goto someone_else_changed_it_unlock;
|
|
|
|
|
rcu_assign_pointer(vnode->permit_cache, replacement);
|
|
|
|
|
spin_unlock(&vnode->lock);
|
|
|
|
|
afs_put_permits(permits);
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
someone_else_changed_it_unlock:
|
|
|
|
|
spin_unlock(&vnode->lock);
|
|
|
|
|
someone_else_changed_it:
|
|
|
|
|
/* Someone else changed the cache under us - don't recheck at this
|
|
|
|
|
* time.
|
|
|
|
|
*/
|
|
|
|
|
return;
|
2007-04-27 06:57:07 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* check with the fileserver to see if the directory or parent directory is
|
|
|
|
|
* permitted to be accessed with this authorisation, and if so, what access it
|
|
|
|
|
* is granted
|
|
|
|
|
*/
|
2017-11-14 00:59:50 +08:00
|
|
|
int afs_check_permit(struct afs_vnode *vnode, struct key *key,
|
|
|
|
|
afs_access_t *_access)
|
2007-04-27 06:57:07 +08:00
|
|
|
{
|
|
|
|
|
struct afs_permits *permits;
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
bool valid = false;
|
|
|
|
|
int i, ret;
|
2007-04-27 06:57:07 +08:00
|
|
|
|
2007-05-09 17:33:45 +08:00
|
|
|
_enter("{%x:%u},%x",
|
|
|
|
|
vnode->fid.vid, vnode->fid.vnode, key_serial(key));
|
2007-04-27 06:57:07 +08:00
|
|
|
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
permits = vnode->permit_cache;
|
2007-04-27 06:57:07 +08:00
|
|
|
|
|
|
|
|
/* check the permits to see if we've got one yet */
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
if (key == vnode->volume->cell->anonymous_key) {
|
2007-04-27 06:57:07 +08:00
|
|
|
_debug("anon");
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
*_access = vnode->status.anon_access;
|
2007-04-27 06:57:07 +08:00
|
|
|
valid = true;
|
|
|
|
|
} else {
|
|
|
|
|
rcu_read_lock();
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
permits = rcu_dereference(vnode->permit_cache);
|
2007-04-27 06:57:07 +08:00
|
|
|
if (permits) {
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
for (i = 0; i < permits->nr_permits; i++) {
|
|
|
|
|
if (permits->permits[i].key < key)
|
|
|
|
|
continue;
|
|
|
|
|
if (permits->permits[i].key > key)
|
2007-04-27 06:57:07 +08:00
|
|
|
break;
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
|
|
|
|
|
*_access = permits->permits[i].access;
|
|
|
|
|
valid = !permits->invalidated;
|
|
|
|
|
break;
|
2007-04-27 06:57:07 +08:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
rcu_read_unlock();
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
if (!valid) {
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
/* Check the status on the file we're actually interested in
|
|
|
|
|
* (the post-processing will cache the result).
|
|
|
|
|
*/
|
2007-04-27 06:57:07 +08:00
|
|
|
_debug("no valid permit");
|
|
|
|
|
|
afs: Overhaul volume and server record caching and fileserver rotation
The current code assumes that volumes and servers are per-cell and are
never shared, but this is not enforced, and, indeed, public cells do exist
that are aliases of each other. Further, an organisation can, say, set up
a public cell and a private cell with overlapping, but not identical, sets
of servers. The difference is purely in the database attached to the VL
servers.
The current code will malfunction if it sees a server in two cells as it
assumes global address -> server record mappings and that each server is in
just one cell.
Further, each server may have multiple addresses - and may have addresses
of different families (IPv4 and IPv6, say).
To this end, the following structural changes are made:
(1) Server record management is overhauled:
(a) Server records are made independent of cell. The namespace keeps
track of them, volume records have lists of them and each vnode
has a server on which its callback interest currently resides.
(b) The cell record no longer keeps a list of servers known to be in
that cell.
(c) The server records are now kept in a flat list because there's no
single address to sort on.
(d) Server records are now keyed by their UUID within the namespace.
(e) The addresses for a server are obtained with the VL.GetAddrsU
rather than with VL.GetEntryByName, using the server's UUID as a
parameter.
(f) Cached server records are garbage collected after a period of
non-use and are counted out of existence before purging is allowed
to complete. This protects the work functions against rmmod.
(g) The servers list is now in /proc/fs/afs/servers.
(2) Volume record management is overhauled:
(a) An RCU-replaceable server list is introduced. This tracks both
servers and their coresponding callback interests.
(b) The superblock is now keyed on cell record and numeric volume ID.
(c) The volume record is now tied to the superblock which mounts it,
and is activated when mounted and deactivated when unmounted.
This makes it easier to handle the cache cookie without causing a
double-use in fscache.
(d) The volume record is loaded from the VLDB using VL.GetEntryByNameU
to get the server UUID list.
(e) The volume name is updated if it is seen to have changed when the
volume is updated (the update is keyed on the volume ID).
(3) The vlocation record is got rid of and VLDB records are no longer
cached. Sufficient information is stored in the volume record, though
an update to a volume record is now no longer shared between related
volumes (volumes come in bundles of three: R/W, R/O and backup).
and the following procedural changes are made:
(1) The fileserver cursor introduced previously is now fleshed out and
used to iterate over fileservers and their addresses.
(2) Volume status is checked during iteration, and the server list is
replaced if a change is detected.
(3) Server status is checked during iteration, and the address list is
replaced if a change is detected.
(4) The abort code is saved into the address list cursor and -ECONNABORTED
returned in afs_make_call() if a remote abort happened rather than
translating the abort into an error message. This allows actions to
be taken depending on the abort code more easily.
(a) If a VMOVED abort is seen then this is handled by rechecking the
volume and restarting the iteration.
(b) If a VBUSY, VRESTARTING or VSALVAGING abort is seen then this is
handled by sleeping for a short period and retrying and/or trying
other servers that might serve that volume. A message is also
displayed once until the condition has cleared.
(c) If a VOFFLINE abort is seen, then this is handled as VBUSY for the
moment.
(d) If a VNOVOL abort is seen, the volume is rechecked in the VLDB to
see if it has been deleted; if not, the fileserver is probably
indicating that the volume couldn't be attached and needs
salvaging.
(e) If statfs() sees one of these aborts, it does not sleep, but
rather returns an error, so as not to block the umount program.
(5) The fileserver iteration functions in vnode.c are now merged into
their callers and more heavily macroised around the cursor. vnode.c
is removed.
(6) Operations on a particular vnode are serialised on that vnode because
the server will lock that vnode whilst it operates on it, so a second
op sent will just have to wait.
(7) Fileservers are probed with FS.GetCapabilities before being used.
This is where service upgrade will be done.
(8) A callback interest on a fileserver is set up before an FS operation
is performed and passed through to afs_make_call() so that it can be
set on the vnode if the operation returns a callback. The callback
interest is passed through to afs_iget() also so that it can be set
there too.
In general, record updating is done on an as-needed basis when we try to
access servers, volumes or vnodes rather than offloading it to work items
and special threads.
Notes:
(1) Pre AFS-3.4 servers are no longer supported, though this can be added
back if necessary (AFS-3.4 was released in 1998).
(2) VBUSY is retried forever for the moment at intervals of 1s.
(3) /proc/fs/afs/<cell>/servers no longer exists.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:50 +08:00
|
|
|
ret = afs_fetch_status(vnode, key);
|
2007-04-27 06:57:07 +08:00
|
|
|
if (ret < 0) {
|
|
|
|
|
*_access = 0;
|
|
|
|
|
_leave(" = %d", ret);
|
|
|
|
|
return ret;
|
|
|
|
|
}
|
2007-05-09 17:33:45 +08:00
|
|
|
*_access = vnode->status.caller_access;
|
2007-04-27 06:57:07 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
_leave(" = 0 [access %x]", *_access);
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* check the permissions on an AFS file
|
|
|
|
|
* - AFS ACLs are attached to directories only, and a file is controlled by its
|
|
|
|
|
* parent directory's ACL
|
|
|
|
|
*/
|
2011-06-21 07:28:19 +08:00
|
|
|
int afs_permission(struct inode *inode, int mask)
|
2007-04-27 06:57:07 +08:00
|
|
|
{
|
|
|
|
|
struct afs_vnode *vnode = AFS_FS_I(inode);
|
2008-02-08 20:20:53 +08:00
|
|
|
afs_access_t uninitialized_var(access);
|
2007-04-27 06:57:07 +08:00
|
|
|
struct key *key;
|
|
|
|
|
int ret;
|
|
|
|
|
|
2011-06-21 07:28:19 +08:00
|
|
|
if (mask & MAY_NOT_BLOCK)
|
2011-01-07 14:49:58 +08:00
|
|
|
return -ECHILD;
|
|
|
|
|
|
2007-05-09 17:33:45 +08:00
|
|
|
_enter("{{%x:%u},%lx},%x,",
|
2007-04-27 06:59:35 +08:00
|
|
|
vnode->fid.vid, vnode->fid.vnode, vnode->flags, mask);
|
2007-04-27 06:57:07 +08:00
|
|
|
|
|
|
|
|
key = afs_request_key(vnode->volume->cell);
|
|
|
|
|
if (IS_ERR(key)) {
|
|
|
|
|
_leave(" = %ld [key]", PTR_ERR(key));
|
|
|
|
|
return PTR_ERR(key);
|
|
|
|
|
}
|
|
|
|
|
|
2017-11-02 23:27:49 +08:00
|
|
|
ret = afs_validate(vnode, key);
|
|
|
|
|
if (ret < 0)
|
|
|
|
|
goto error;
|
2007-04-27 06:59:35 +08:00
|
|
|
|
2007-04-27 06:57:07 +08:00
|
|
|
/* check the permits to see if we've got one yet */
|
|
|
|
|
ret = afs_check_permit(vnode, key, &access);
|
2007-04-27 06:59:35 +08:00
|
|
|
if (ret < 0)
|
|
|
|
|
goto error;
|
2007-04-27 06:57:07 +08:00
|
|
|
|
|
|
|
|
/* interpret the access mask */
|
|
|
|
|
_debug("REQ %x ACC %x on %s",
|
|
|
|
|
mask, access, S_ISDIR(inode->i_mode) ? "dir" : "file");
|
|
|
|
|
|
|
|
|
|
if (S_ISDIR(inode->i_mode)) {
|
|
|
|
|
if (mask & MAY_EXEC) {
|
|
|
|
|
if (!(access & AFS_ACE_LOOKUP))
|
|
|
|
|
goto permission_denied;
|
|
|
|
|
} else if (mask & MAY_READ) {
|
2017-07-06 22:50:18 +08:00
|
|
|
if (!(access & AFS_ACE_LOOKUP))
|
2007-04-27 06:57:07 +08:00
|
|
|
goto permission_denied;
|
|
|
|
|
} else if (mask & MAY_WRITE) {
|
|
|
|
|
if (!(access & (AFS_ACE_DELETE | /* rmdir, unlink, rename from */
|
2017-07-06 22:50:18 +08:00
|
|
|
AFS_ACE_INSERT))) /* create, mkdir, symlink, rename to */
|
2007-04-27 06:57:07 +08:00
|
|
|
goto permission_denied;
|
|
|
|
|
} else {
|
|
|
|
|
BUG();
|
|
|
|
|
}
|
|
|
|
|
} else {
|
|
|
|
|
if (!(access & AFS_ACE_LOOKUP))
|
|
|
|
|
goto permission_denied;
|
2017-03-17 00:27:44 +08:00
|
|
|
if ((mask & MAY_EXEC) && !(inode->i_mode & S_IXUSR))
|
|
|
|
|
goto permission_denied;
|
2007-04-27 06:57:07 +08:00
|
|
|
if (mask & (MAY_EXEC | MAY_READ)) {
|
|
|
|
|
if (!(access & AFS_ACE_READ))
|
|
|
|
|
goto permission_denied;
|
2017-03-17 00:27:44 +08:00
|
|
|
if (!(inode->i_mode & S_IRUSR))
|
|
|
|
|
goto permission_denied;
|
2007-04-27 06:57:07 +08:00
|
|
|
} else if (mask & MAY_WRITE) {
|
|
|
|
|
if (!(access & AFS_ACE_WRITE))
|
|
|
|
|
goto permission_denied;
|
2017-03-17 00:27:44 +08:00
|
|
|
if (!(inode->i_mode & S_IWUSR))
|
|
|
|
|
goto permission_denied;
|
2007-04-27 06:57:07 +08:00
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
key_put(key);
|
2007-04-27 06:59:35 +08:00
|
|
|
_leave(" = %d", ret);
|
|
|
|
|
return ret;
|
2007-04-27 06:57:07 +08:00
|
|
|
|
|
|
|
|
permission_denied:
|
2007-04-27 06:59:35 +08:00
|
|
|
ret = -EACCES;
|
|
|
|
|
error:
|
2007-04-27 06:57:07 +08:00
|
|
|
key_put(key);
|
2007-04-27 06:59:35 +08:00
|
|
|
_leave(" = %d", ret);
|
|
|
|
|
return ret;
|
2007-04-27 06:57:07 +08:00
|
|
|
}
|
afs: Overhaul permit caching
Overhaul permit caching in AFS by making it per-vnode and sharing permit
lists where possible.
When most of the fileserver operations are called, they return a status
structure indicating the (revised) details of the vnode or vnodes involved
in the operation. This includes the access mark derived from the ACL
(named CallerAccess in the protocol definition file). This is cacheable
and if the ACL changes, the server will tell us that it is breaking the
callback promise, at which point we can discard the currently cached
permits.
With this patch, the afs_permits structure has, at the end, an array of
{ key, CallerAccess } elements, sorted by key pointer. This is then cached
in a hash table so that it can be shared between vnodes with the same
access permits.
Permit lists can only be shared if they contain the exact same set of
key->CallerAccess mappings.
Note that that table is global rather than being per-net_ns. If the keys
in a permit list cross net_ns boundaries, there is no problem sharing the
cached permits, since the permits are just integer masks.
Since permit lists pin keys, the permit cache also makes it easier for a
future patch to find all occurrences of a key and remove them by means of
setting the afs_permits::invalidated flag and then clearing the appropriate
key pointer. In such an event, memory barriers will need adding.
Lastly, the permit caching is skipped if the server has sent either a
vnode-specific or an entire-server callback since the start of the
operation.
Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-02 23:27:49 +08:00
|
|
|
|
|
|
|
|
void __exit afs_clean_up_permit_cache(void)
|
|
|
|
|
{
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
for (i = 0; i < HASH_SIZE(afs_permits_cache); i++)
|
|
|
|
|
WARN_ON_ONCE(!hlist_empty(&afs_permits_cache[i]));
|
|
|
|
|
|
|
|
|
|
}
|