kernel-fxtec-pro1x/fs/fscache/stats.c
David Howells e3d4d28b1c FS-Cache: Handle read request vs lookup, creation or other cache failure
FS-Cache doesn't correctly handle the netfs requesting a read from the cache
on an object that failed or was withdrawn by the cache.  A trace similar to
the following might be seen:

	CacheFiles: Lookup failed error -105
	[exe   ] unexpected submission OP165afe [OBJ6cac OBJECT_LC_DYING]
	[exe   ] objstate=OBJECT_LC_DYING [OBJECT_LC_DYING]
	[exe   ] objflags=0
	[exe   ] objevent=9 [fffffffffffffffb]
	[exe   ] ops=0 inp=0 exc=0
	Pid: 6970, comm: exe Not tainted 2.6.32-rc6-cachefs #50
	Call Trace:
	 [<ffffffffa0076477>] fscache_submit_op+0x3ff/0x45a [fscache]
	 [<ffffffffa0077997>] __fscache_read_or_alloc_pages+0x187/0x3c4 [fscache]
	 [<ffffffffa00b6480>] ? nfs_readpage_from_fscache_complete+0x0/0x66 [nfs]
	 [<ffffffffa00b6388>] __nfs_readpages_from_fscache+0x7e/0x176 [nfs]
	 [<ffffffff8108e483>] ? __alloc_pages_nodemask+0x11c/0x5cf
	 [<ffffffffa009d796>] nfs_readpages+0x114/0x1d7 [nfs]
	 [<ffffffff81090314>] __do_page_cache_readahead+0x15f/0x1ec
	 [<ffffffff81090228>] ? __do_page_cache_readahead+0x73/0x1ec
	 [<ffffffff810903bd>] ra_submit+0x1c/0x20
	 [<ffffffff810906bb>] ondemand_readahead+0x227/0x23a
	 [<ffffffff81090762>] page_cache_sync_readahead+0x17/0x19
	 [<ffffffff8108a99e>] generic_file_aio_read+0x236/0x5a0
	 [<ffffffffa00937bd>] nfs_file_read+0xe4/0xf3 [nfs]
	 [<ffffffff810b2fa2>] do_sync_read+0xe3/0x120
	 [<ffffffff81354cc3>] ? _spin_unlock_irq+0x2b/0x31
	 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34
	 [<ffffffff811848e5>] ? selinux_file_permission+0x5d/0x10f
	 [<ffffffff81352bdb>] ? thread_return+0x3e/0x101
	 [<ffffffff8117d7b0>] ? security_file_permission+0x11/0x13
	 [<ffffffff810b3b06>] vfs_read+0xaa/0x16f
	 [<ffffffff81058df0>] ? trace_hardirqs_on_caller+0x10c/0x130
	 [<ffffffff810b3c84>] sys_read+0x45/0x6c
	 [<ffffffff8100ae2b>] system_call_fastpath+0x16/0x1b

The object state might also be OBJECT_DYING or OBJECT_WITHDRAWING.

This should be handled by simply rejecting the new operation with ENOBUFS.
There's no need to log an error for it.  Events of this type now appear in the
stats file under Ops:rej.

Signed-off-by: David Howells <dhowells@redhat.com>
2009-11-19 18:11:32 +00:00

261 lines
8.8 KiB
C

/* FS-Cache statistics
*
* 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.
*/
#define FSCACHE_DEBUG_LEVEL THREAD
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include "internal.h"
/*
* operation counters
*/
atomic_t fscache_n_op_pend;
atomic_t fscache_n_op_run;
atomic_t fscache_n_op_enqueue;
atomic_t fscache_n_op_requeue;
atomic_t fscache_n_op_deferred_release;
atomic_t fscache_n_op_release;
atomic_t fscache_n_op_gc;
atomic_t fscache_n_op_cancelled;
atomic_t fscache_n_op_rejected;
atomic_t fscache_n_attr_changed;
atomic_t fscache_n_attr_changed_ok;
atomic_t fscache_n_attr_changed_nobufs;
atomic_t fscache_n_attr_changed_nomem;
atomic_t fscache_n_attr_changed_calls;
atomic_t fscache_n_allocs;
atomic_t fscache_n_allocs_ok;
atomic_t fscache_n_allocs_wait;
atomic_t fscache_n_allocs_nobufs;
atomic_t fscache_n_allocs_intr;
atomic_t fscache_n_alloc_ops;
atomic_t fscache_n_alloc_op_waits;
atomic_t fscache_n_retrievals;
atomic_t fscache_n_retrievals_ok;
atomic_t fscache_n_retrievals_wait;
atomic_t fscache_n_retrievals_nodata;
atomic_t fscache_n_retrievals_nobufs;
atomic_t fscache_n_retrievals_intr;
atomic_t fscache_n_retrievals_nomem;
atomic_t fscache_n_retrieval_ops;
atomic_t fscache_n_retrieval_op_waits;
atomic_t fscache_n_stores;
atomic_t fscache_n_stores_ok;
atomic_t fscache_n_stores_again;
atomic_t fscache_n_stores_nobufs;
atomic_t fscache_n_stores_oom;
atomic_t fscache_n_store_ops;
atomic_t fscache_n_store_calls;
atomic_t fscache_n_store_pages;
atomic_t fscache_n_store_radix_deletes;
atomic_t fscache_n_store_pages_over_limit;
atomic_t fscache_n_marks;
atomic_t fscache_n_uncaches;
atomic_t fscache_n_acquires;
atomic_t fscache_n_acquires_null;
atomic_t fscache_n_acquires_no_cache;
atomic_t fscache_n_acquires_ok;
atomic_t fscache_n_acquires_nobufs;
atomic_t fscache_n_acquires_oom;
atomic_t fscache_n_updates;
atomic_t fscache_n_updates_null;
atomic_t fscache_n_updates_run;
atomic_t fscache_n_relinquishes;
atomic_t fscache_n_relinquishes_null;
atomic_t fscache_n_relinquishes_waitcrt;
atomic_t fscache_n_cookie_index;
atomic_t fscache_n_cookie_data;
atomic_t fscache_n_cookie_special;
atomic_t fscache_n_object_alloc;
atomic_t fscache_n_object_no_alloc;
atomic_t fscache_n_object_lookups;
atomic_t fscache_n_object_lookups_negative;
atomic_t fscache_n_object_lookups_positive;
atomic_t fscache_n_object_created;
atomic_t fscache_n_object_avail;
atomic_t fscache_n_object_dead;
atomic_t fscache_n_checkaux_none;
atomic_t fscache_n_checkaux_okay;
atomic_t fscache_n_checkaux_update;
atomic_t fscache_n_checkaux_obsolete;
atomic_t fscache_n_cop_alloc_object;
atomic_t fscache_n_cop_lookup_object;
atomic_t fscache_n_cop_lookup_complete;
atomic_t fscache_n_cop_grab_object;
atomic_t fscache_n_cop_update_object;
atomic_t fscache_n_cop_drop_object;
atomic_t fscache_n_cop_put_object;
atomic_t fscache_n_cop_sync_cache;
atomic_t fscache_n_cop_attr_changed;
atomic_t fscache_n_cop_read_or_alloc_page;
atomic_t fscache_n_cop_read_or_alloc_pages;
atomic_t fscache_n_cop_allocate_page;
atomic_t fscache_n_cop_allocate_pages;
atomic_t fscache_n_cop_write_page;
atomic_t fscache_n_cop_uncache_page;
atomic_t fscache_n_cop_dissociate_pages;
/*
* display the general statistics
*/
static int fscache_stats_show(struct seq_file *m, void *v)
{
seq_puts(m, "FS-Cache statistics\n");
seq_printf(m, "Cookies: idx=%u dat=%u spc=%u\n",
atomic_read(&fscache_n_cookie_index),
atomic_read(&fscache_n_cookie_data),
atomic_read(&fscache_n_cookie_special));
seq_printf(m, "Objects: alc=%u nal=%u avl=%u ded=%u\n",
atomic_read(&fscache_n_object_alloc),
atomic_read(&fscache_n_object_no_alloc),
atomic_read(&fscache_n_object_avail),
atomic_read(&fscache_n_object_dead));
seq_printf(m, "ChkAux : non=%u ok=%u upd=%u obs=%u\n",
atomic_read(&fscache_n_checkaux_none),
atomic_read(&fscache_n_checkaux_okay),
atomic_read(&fscache_n_checkaux_update),
atomic_read(&fscache_n_checkaux_obsolete));
seq_printf(m, "Pages : mrk=%u unc=%u\n",
atomic_read(&fscache_n_marks),
atomic_read(&fscache_n_uncaches));
seq_printf(m, "Acquire: n=%u nul=%u noc=%u ok=%u nbf=%u"
" oom=%u\n",
atomic_read(&fscache_n_acquires),
atomic_read(&fscache_n_acquires_null),
atomic_read(&fscache_n_acquires_no_cache),
atomic_read(&fscache_n_acquires_ok),
atomic_read(&fscache_n_acquires_nobufs),
atomic_read(&fscache_n_acquires_oom));
seq_printf(m, "Lookups: n=%u neg=%u pos=%u crt=%u\n",
atomic_read(&fscache_n_object_lookups),
atomic_read(&fscache_n_object_lookups_negative),
atomic_read(&fscache_n_object_lookups_positive),
atomic_read(&fscache_n_object_created));
seq_printf(m, "Updates: n=%u nul=%u run=%u\n",
atomic_read(&fscache_n_updates),
atomic_read(&fscache_n_updates_null),
atomic_read(&fscache_n_updates_run));
seq_printf(m, "Relinqs: n=%u nul=%u wcr=%u\n",
atomic_read(&fscache_n_relinquishes),
atomic_read(&fscache_n_relinquishes_null),
atomic_read(&fscache_n_relinquishes_waitcrt));
seq_printf(m, "AttrChg: n=%u ok=%u nbf=%u oom=%u run=%u\n",
atomic_read(&fscache_n_attr_changed),
atomic_read(&fscache_n_attr_changed_ok),
atomic_read(&fscache_n_attr_changed_nobufs),
atomic_read(&fscache_n_attr_changed_nomem),
atomic_read(&fscache_n_attr_changed_calls));
seq_printf(m, "Allocs : n=%u ok=%u wt=%u nbf=%u int=%u\n",
atomic_read(&fscache_n_allocs),
atomic_read(&fscache_n_allocs_ok),
atomic_read(&fscache_n_allocs_wait),
atomic_read(&fscache_n_allocs_nobufs),
atomic_read(&fscache_n_allocs_intr));
seq_printf(m, "Allocs : ops=%u owt=%u\n",
atomic_read(&fscache_n_alloc_ops),
atomic_read(&fscache_n_alloc_op_waits));
seq_printf(m, "Retrvls: n=%u ok=%u wt=%u nod=%u nbf=%u"
" int=%u oom=%u\n",
atomic_read(&fscache_n_retrievals),
atomic_read(&fscache_n_retrievals_ok),
atomic_read(&fscache_n_retrievals_wait),
atomic_read(&fscache_n_retrievals_nodata),
atomic_read(&fscache_n_retrievals_nobufs),
atomic_read(&fscache_n_retrievals_intr),
atomic_read(&fscache_n_retrievals_nomem));
seq_printf(m, "Retrvls: ops=%u owt=%u\n",
atomic_read(&fscache_n_retrieval_ops),
atomic_read(&fscache_n_retrieval_op_waits));
seq_printf(m, "Stores : n=%u ok=%u agn=%u nbf=%u oom=%u\n",
atomic_read(&fscache_n_stores),
atomic_read(&fscache_n_stores_ok),
atomic_read(&fscache_n_stores_again),
atomic_read(&fscache_n_stores_nobufs),
atomic_read(&fscache_n_stores_oom));
seq_printf(m, "Stores : ops=%u run=%u pgs=%u rxd=%u olm=%u\n",
atomic_read(&fscache_n_store_ops),
atomic_read(&fscache_n_store_calls),
atomic_read(&fscache_n_store_pages),
atomic_read(&fscache_n_store_radix_deletes),
atomic_read(&fscache_n_store_pages_over_limit));
seq_printf(m, "Ops : pend=%u run=%u enq=%u can=%u rej=%u\n",
atomic_read(&fscache_n_op_pend),
atomic_read(&fscache_n_op_run),
atomic_read(&fscache_n_op_enqueue),
atomic_read(&fscache_n_op_cancelled),
atomic_read(&fscache_n_op_rejected));
seq_printf(m, "Ops : dfr=%u rel=%u gc=%u\n",
atomic_read(&fscache_n_op_deferred_release),
atomic_read(&fscache_n_op_release),
atomic_read(&fscache_n_op_gc));
seq_printf(m, "CacheOp: alo=%d luo=%d luc=%d gro=%d\n",
atomic_read(&fscache_n_cop_alloc_object),
atomic_read(&fscache_n_cop_lookup_object),
atomic_read(&fscache_n_cop_lookup_complete),
atomic_read(&fscache_n_cop_grab_object));
seq_printf(m, "CacheOp: upo=%d dro=%d pto=%d atc=%d syn=%d\n",
atomic_read(&fscache_n_cop_update_object),
atomic_read(&fscache_n_cop_drop_object),
atomic_read(&fscache_n_cop_put_object),
atomic_read(&fscache_n_cop_attr_changed),
atomic_read(&fscache_n_cop_sync_cache));
seq_printf(m, "CacheOp: rap=%d ras=%d alp=%d als=%d wrp=%d ucp=%d dsp=%d\n",
atomic_read(&fscache_n_cop_read_or_alloc_page),
atomic_read(&fscache_n_cop_read_or_alloc_pages),
atomic_read(&fscache_n_cop_allocate_page),
atomic_read(&fscache_n_cop_allocate_pages),
atomic_read(&fscache_n_cop_write_page),
atomic_read(&fscache_n_cop_uncache_page),
atomic_read(&fscache_n_cop_dissociate_pages));
return 0;
}
/*
* open "/proc/fs/fscache/stats" allowing provision of a statistical summary
*/
static int fscache_stats_open(struct inode *inode, struct file *file)
{
return single_open(file, fscache_stats_show, NULL);
}
const struct file_operations fscache_stats_fops = {
.owner = THIS_MODULE,
.open = fscache_stats_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};