/*
 * linux/fs/nfs/cache_lib.c
 *
 * Helper routines for the NFS client caches
 *
 * Copyright (c) 2009 Trond Myklebust <Trond.Myklebust@netapp.com>
 */
#include <linux/kmod.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/slab.h>
#include <linux/sunrpc/cache.h>
#include <linux/sunrpc/rpc_pipe_fs.h>
#include <net/net_namespace.h>

#include "cache_lib.h"

#define NFS_CACHE_UPCALL_PATHLEN 256
#define NFS_CACHE_UPCALL_TIMEOUT 15

static char nfs_cache_getent_prog[NFS_CACHE_UPCALL_PATHLEN] =
				"/sbin/nfs_cache_getent";
static unsigned long nfs_cache_getent_timeout = NFS_CACHE_UPCALL_TIMEOUT;

module_param_string(cache_getent, nfs_cache_getent_prog,
		sizeof(nfs_cache_getent_prog), 0600);
MODULE_PARM_DESC(cache_getent, "Path to the client cache upcall program");
module_param_named(cache_getent_timeout, nfs_cache_getent_timeout, ulong, 0600);
MODULE_PARM_DESC(cache_getent_timeout, "Timeout (in seconds) after which "
		"the cache upcall is assumed to have failed");

int nfs_cache_upcall(struct cache_detail *cd, char *entry_name)
{
	static char *envp[] = { "HOME=/",
		"TERM=linux",
		"PATH=/sbin:/usr/sbin:/bin:/usr/bin",
		NULL
	};
	char *argv[] = {
		nfs_cache_getent_prog,
		cd->name,
		entry_name,
		NULL
	};
	int ret = -EACCES;

	if (nfs_cache_getent_prog[0] == '\0')
		goto out;
	ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
	/*
	 * Disable the upcall mechanism if we're getting an ENOENT or
	 * EACCES error. The admin can re-enable it on the fly by using
	 * sysfs to set the 'cache_getent' parameter once the problem
	 * has been fixed.
	 */
	if (ret == -ENOENT || ret == -EACCES)
		nfs_cache_getent_prog[0] = '\0';
out:
	return ret > 0 ? 0 : ret;
}

/*
 * Deferred request handling
 */
void nfs_cache_defer_req_put(struct nfs_cache_defer_req *dreq)
{
	if (atomic_dec_and_test(&dreq->count))
		kfree(dreq);
}

static void nfs_dns_cache_revisit(struct cache_deferred_req *d, int toomany)
{
	struct nfs_cache_defer_req *dreq;

	dreq = container_of(d, struct nfs_cache_defer_req, deferred_req);

	complete(&dreq->completion);
	nfs_cache_defer_req_put(dreq);
}

static struct cache_deferred_req *nfs_dns_cache_defer(struct cache_req *req)
{
	struct nfs_cache_defer_req *dreq;

	dreq = container_of(req, struct nfs_cache_defer_req, req);
	dreq->deferred_req.revisit = nfs_dns_cache_revisit;
	atomic_inc(&dreq->count);

	return &dreq->deferred_req;
}

struct nfs_cache_defer_req *nfs_cache_defer_req_alloc(void)
{
	struct nfs_cache_defer_req *dreq;

	dreq = kzalloc(sizeof(*dreq), GFP_KERNEL);
	if (dreq) {
		init_completion(&dreq->completion);
		atomic_set(&dreq->count, 1);
		dreq->req.defer = nfs_dns_cache_defer;
	}
	return dreq;
}

int nfs_cache_wait_for_upcall(struct nfs_cache_defer_req *dreq)
{
	if (wait_for_completion_timeout(&dreq->completion,
			nfs_cache_getent_timeout * HZ) == 0)
		return -ETIMEDOUT;
	return 0;
}

int nfs_cache_register_sb(struct super_block *sb, struct cache_detail *cd)
{
	int ret;
	struct dentry *dir;

	dir = rpc_d_lookup_sb(sb, "cache");
	ret = sunrpc_cache_register_pipefs(dir, cd->name, 0600, cd);
	dput(dir);
	return ret;
}

int nfs_cache_register_net(struct net *net, struct cache_detail *cd)
{
	struct super_block *pipefs_sb;
	int ret = 0;

	sunrpc_init_cache_detail(cd);
	pipefs_sb = rpc_get_sb_net(net);
	if (pipefs_sb) {
		ret = nfs_cache_register_sb(pipefs_sb, cd);
		rpc_put_sb_net(net);
		if (ret)
			sunrpc_destroy_cache_detail(cd);
	}
	return ret;
}

void nfs_cache_unregister_sb(struct super_block *sb, struct cache_detail *cd)
{
	if (cd->u.pipefs.dir)
		sunrpc_cache_unregister_pipefs(cd);
}

void nfs_cache_unregister_net(struct net *net, struct cache_detail *cd)
{
	struct super_block *pipefs_sb;

	pipefs_sb = rpc_get_sb_net(net);
	if (pipefs_sb) {
		nfs_cache_unregister_sb(pipefs_sb, cd);
		rpc_put_sb_net(net);
	}
	sunrpc_destroy_cache_detail(cd);
}
tion value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Christoph Hellwig &lt;hch@lst.de&gt;</td><td class='right'>2017-01-30 13:15:41 +0100</td></tr>
<tr><th>committer</th><td>Bjorn Helgaas &lt;bhelgaas@google.com&gt;</td><td class='right'>2017-02-02 10:35:46 -0600</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/perf/util?h=nds-private-remove&amp;id=dfef358bd1beb4e7b5c94eca944be9cd23dfc752'>dfef358bd1beb4e7b5c94eca944be9cd23dfc752</a> (<a href='/cgit.cgi/linux/net-next.git/patch/tools/perf/util?id=dfef358bd1beb4e7b5c94eca944be9cd23dfc752'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=dfef358bd1beb4e7b5c94eca944be9cd23dfc752'>b9a2afb38a4c2ac8ad31f49ec0d71fe9e5b1994c</a> /<a href='/cgit.cgi/linux/net-next.git/tree/tools/perf/util?h=nds-private-remove&amp;id=dfef358bd1beb4e7b5c94eca944be9cd23dfc752'>tools/perf/util</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/perf/util?h=nds-private-remove&amp;id=030305d69fc6963c16003f50d7e8d74b02d0a143'>030305d69fc6963c16003f50d7e8d74b02d0a143</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/perf/util?h=nds-private-remove&amp;id=dfef358bd1beb4e7b5c94eca944be9cd23dfc752&amp;id2=030305d69fc6963c16003f50d7e8d74b02d0a143'>diff</a>)</td></tr></table>
<div class='commit-subject'>PCI/MSI: Don't apply affinity if there aren't enough vectors left</div><div class='commit-msg'>Bart reported a problem wіth an out of bounds access in the low-level IRQ
affinity code, which we root caused to the qla2xxx driver assigning all its
MSI-X vectors to the pre and post vectors, and not having any left for the
actually spread IRQs.

Fix this issue by not asking for affinity assignment when there are no
vectors to assign left.

Fixes: 402723ad5c62 ("PCI/MSI: Provide pci_alloc_irq_vectors_affinity()")
Link: https://lkml.kernel.org/r/1485359225.3093.3.camel@sandisk.com
Reported-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Tested-by: Bart Van Assche &lt;bart.vanassche@sandisk.com&gt;
Signed-off-by: Christoph Hellwig &lt;hch@lst.de&gt;
Signed-off-by: Bjorn Helgaas &lt;bhelgaas@google.com&gt;</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=dfef358bd1beb4e7b5c94eca944be9cd23dfc752'>Diffstat</a> (limited to 'tools/perf/util')</div><table summary='diffstat' class='diffstat'>