/*
 * Copyright (c) 2016 Tom Haynes <loghyr@primarydata.com>
 *
 * The following implements a super-simple flex-file server
 * where the NFSv4.1 mds is also the ds. And the storage is
 * the same. I.e., writing to the mds via a NFSv4.1 WRITE
 * goes to the same location as the NFSv3 WRITE.
 */
#include <linux/slab.h>

#include <linux/nfsd/debug.h>

#include <linux/sunrpc/addr.h>

#include "flexfilelayoutxdr.h"
#include "pnfs.h"

#define NFSDDBG_FACILITY	NFSDDBG_PNFS

static __be32
nfsd4_ff_proc_layoutget(struct inode *inode, const struct svc_fh *fhp,
		struct nfsd4_layoutget *args)
{
	struct nfsd4_layout_seg *seg = &args->lg_seg;
	u32 device_generation = 0;
	int error;
	uid_t u;

	struct pnfs_ff_layout *fl;

	/*
	 * The super simple flex file server has 1 mirror, 1 data server,
	 * and 1 file handle. So instead of 4 allocs, do 1 for now.
	 * Zero it out for the stateid - don't want junk in there!
	 */
	error = -ENOMEM;
	fl = kzalloc(sizeof(*fl), GFP_KERNEL);
	if (!fl)
		goto out_error;
	args->lg_content = fl;

	/*
	 * Avoid layout commit, try to force the I/O to the DS,
	 * and for fun, cause all IOMODE_RW layout segments to
	 * effectively be WRITE only.
	 */
	fl->flags = FF_FLAGS_NO_LAYOUTCOMMIT | FF_FLAGS_NO_IO_THRU_MDS |
		    FF_FLAGS_NO_READ_IO;

	/* Do not allow a IOMODE_READ segment to have write pemissions */
	if (seg->iomode == IOMODE_READ) {
		u = from_kuid(&init_user_ns, inode->i_uid) + 1;
		fl->uid = make_kuid(&init_user_ns, u);
	} else
		fl->uid = inode->i_uid;
	fl->gid = inode->i_gid;

	error = nfsd4_set_deviceid(&fl->deviceid, fhp, device_generation);
	if (error)
		goto out_error;

	fl->fh.size = fhp->fh_handle.fh_size;
	memcpy(fl->fh.data, &fhp->fh_handle.fh_base, fl->fh.size);

	/* Give whole file layout segments */
	seg->offset = 0;
	seg->length = NFS4_MAX_UINT64;

	dprintk("GET: 0x%llx:0x%llx %d\n", seg->offset, seg->length,
		seg->iomode);
	return 0;

out_error:
	seg->length = 0;
	return nfserrno(error);
}

static __be32
nfsd4_ff_proc_getdeviceinfo(struct super_block *sb, struct svc_rqst *rqstp,
		struct nfs4_client *clp, struct nfsd4_getdeviceinfo *gdp)
{
	struct pnfs_ff_device_addr *da;

	u16 port;
	char addr[INET6_ADDRSTRLEN];

	da = kzalloc(sizeof(struct pnfs_ff_device_addr), GFP_KERNEL);
	if (!da)
		return nfserrno(-ENOMEM);

	gdp->gd_device = da;

	da->version = 3;
	da->minor_version = 0;

	da->rsize = svc_max_payload(rqstp);
	da->wsize = da->rsize;

	rpc_ntop((struct sockaddr *)&rqstp->rq_daddr,
		 addr, INET6_ADDRSTRLEN);
	if (rqstp->rq_daddr.ss_family == AF_INET) {
		struct sockaddr_in *sin;

		sin = (struct sockaddr_in *)&rqstp->rq_daddr;
		port = ntohs(sin->sin_port);
		snprintf(da->netaddr.netid, FF_NETID_LEN + 1, "tcp");
		da->netaddr.netid_len = 3;
	} else {
		struct sockaddr_in6 *sin6;

		sin6 = (struct sockaddr_in6 *)&rqstp->rq_daddr;
		port = ntohs(sin6->sin6_port);
		snprintf(da->netaddr.netid, FF_NETID_LEN + 1, "tcp6");
		da->netaddr.netid_len = 4;
	}

	da->netaddr.addr_len =
		snprintf(da->netaddr.addr, FF_ADDR_LEN + 1,
			 "%s.%hhu.%hhu", addr, port >> 8, port & 0xff);

	da->tightly_coupled = false;

	return 0;
}

const struct nfsd4_layout_ops ff_layout_ops = {
	.notify_types		=
			NOTIFY_DEVICEID4_DELETE | NOTIFY_DEVICEID4_CHANGE,
	.disable_recalls	= true,
	.proc_getdeviceinfo	= nfsd4_ff_proc_getdeviceinfo,
	.encode_getdeviceinfo	= nfsd4_ff_encode_getdeviceinfo,
	.proc_layoutget		= nfsd4_ff_proc_layoutget,
	.encode_layoutget	= nfsd4_ff_encode_layoutget,
};
<option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option 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>Jiri Kosina &lt;jkosina@suse.cz&gt;</td><td class='right'>2017-01-27 22:25:52 +0000</td></tr>
<tr><th>committer</th><td>Ingo Molnar &lt;mingo@kernel.org&gt;</td><td class='right'>2017-01-28 09:18:56 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/sched/cls_rsvp6.c?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>bf29bddf0417a4783da3b24e8c9e017ac649326f</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/sched/cls_rsvp6.c?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>54a05a4883b73f80e4e1d8c4b15750aa01c39932</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/sched/cls_rsvp6.c?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>net/sched/cls_rsvp6.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/sched/cls_rsvp6.c?id=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>883af14e67e8b8702b5560aa64c888c0cd0bd66c</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/sched/cls_rsvp6.c?id=bf29bddf0417a4783da3b24e8c9e017ac649326f&amp;id2=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>diff</a>)</td></tr></table>
<div class='commit-subject'>x86/efi: Always map the first physical page into the EFI pagetables</div><div class='commit-msg'>Commit:

  129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode")

stopped creating 1:1 mappings for all RAM, when running in native 64-bit mode.

It turns out though that there are 64-bit EFI implementations in the wild
(this particular problem has been reported on a Lenovo Yoga 710-11IKB),
which still make use of the first physical page for their own private use,
even though they explicitly mark it EFI_CONVENTIONAL_MEMORY in the memory
map.

In case there is no mapping for this particular frame in the EFI pagetables,
as soon as firmware tries to make use of it, a triple fault occurs and the
system reboots (in case of the Yoga 710-11IKB this is very early during bootup).

Fix that by always mapping the first page of physical memory into the EFI
pagetables. We're free to hand this page to the BIOS, as trim_bios_range()
will reserve the first page and isolate it away from memory allocators anyway.

Note that just reverting 129766708 alone is not enough on v4.9-rc1+ to fix the
regression on affected hardware, as this commit:

   ab72a27da ("x86/efi: Consolidate region mapping logic")

later made the first physical frame not to be mapped anyway.

Reported-by: Hanka Pavlikova &lt;hanka@ucw.cz&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
Signed-off-by: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Cc: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Laura Abbott &lt;labbott@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vojtech Pavlik &lt;vojtech@ucw.cz&gt;
Cc: Waiman Long &lt;waiman.long@hpe.com&gt;
Cc: linux-efi@vger.kernel.org
Cc: stable@kernel.org # v4.8+
Fixes: 129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode")
Link: http://lkml.kernel.org/r/20170127222552.22336-1-matt@codeblueprint.co.uk
[ Tidied up the changelog and the comment. ]
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>Diffstat</a> (limited to 'net/sched/cls_rsvp6.c')</div><table summary='diffstat' class='diffstat'>