Commit Graph

4324 Commits

Author SHA1 Message Date
Rick Macklem
9516bcdfb4 Modify writing to mirrored pNFS DSs to prepare for use of ext_pgs mbufs.
This patch modifies writing to mirrored pNFS DSs slightly so that there is
only one m_copym() call for a mirrored pair instead of two of them.
This call replaces the custom nfsm_copym() call, which is no longer needed
and deleted by this patch. The patch does introduce a new nfsm_split()
function that only calls m_split() for the non-ext_pgs case.
The semantics of nfsm_uiombuflist() is changed to include code that nul
pads the generated mbuf list. This was done by nfsm_copym() prior to this patch.

The main reason for this change is that it allows the data to be a list
of ext_pgs mbufs, since the m_copym() is for the entire mbuf list.
This support will be added in a future commit.

This patch only affects writing to mirrored flexible file layout pNFS servers.
2020-07-22 23:33:37 +00:00
Alexander V. Chernikov
e1c05fd290 Transition from rtrequest1_fib() to rib_action().
Remove all variations of rtrequest <rtrequest1_fib, rtrequest_fib,
 in6_rtrequest, rtrequest_fib> and their uses and switch to
 to rib_action(). This is part of the new routing KPI.

Submitted by: Neel Chauhan <neel AT neelc DOT org>
Differential Revision: https://reviews.freebsd.org/D25546
2020-07-21 19:56:13 +00:00
Mark Johnston
39bc40e3d2 ext2fs: Stop checking for failures from malloc(M_WAITOK).
PR:		240545
Submitted by:	Andrew Reiter <arr@watson.org>
Reviewed by:	fsu
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D25707
2020-07-20 14:28:26 +00:00
Alexander V. Chernikov
725871230d Temporarly revert r363319 to unbreak the build.
Reported by:	CI
Pointy hat to: melifaro
2020-07-19 10:53:15 +00:00
Alexander V. Chernikov
8cee15d9e4 Transition from rtrequest1_fib() to rib_action().
Remove all variations of rtrequest <rtrequest1_fib, rtrequest_fib,
 in6_rtrequest, rtrequest_fib> and their uses and switch to
to rib_action(). This is part of the new routing KPI.

Submitted by:	Neel Chauhan <neel AT neelc DOT org>
Differential Revision:	https://reviews.freebsd.org/D25546
2020-07-19 09:29:27 +00:00
Rick Macklem
7477442fdd Fix the pNFS flexible file layout client for servers with small write size.
The code in nfscl_dofflayout() loops when a flexible file layout server
provides a small write data limit (no extant server is known to do this).
If/when it looped, it erroneously reused the "drpc" argument for the
mirror worker thread, corrupting it.
This patch fixes the problem by only using the calling thread after the
first loop iteration.

Found during testing by simulating a server with a small write size.

Since no extant pNFS server is known to provide a small write size,
this fix it not needed in practice at this time.

MFC after:	2 weeks
2020-07-15 01:26:28 +00:00
Rick Macklem
6722f6e577 Minor code cleanup that removes "nd->nd_bpos = mcp;" in both if and else.
The statement "nd->nd_bpos = mcp;" was in both the if and else. Correct,
but potentially confusing.  This patch fixes this.

There should be no semantics change caused by this commit.
2020-07-13 01:28:45 +00:00
Rick Macklem
3eaf03766e Add support for ext_pgs mbufs to nfsm_uiombuf().
This patch uses a slightly different algorithm for the non-ext_pgs case,
where a variable called "mcp" is maintained, pointing to the current
location that mbuf data can be filled into. This avoids use of
mtod(mp, char *) + mp->m_len to calculate the location, since this does
not work for ext_pgs mbufs and I think it makes the algorithm more readable.
This change should not result in semantic changes for the non-ext_pgs case.

This is another in the series of commits that add support to the NFS client
and server for building RPC messages in ext_pgs mbufs with anonymous pages.
This is useful so that the entire mbuf list does not need to be
copied before calling sosend() when NFS over TLS is enabled.

Since ND_EXTPG is never set yet, there is no semantic change at this time.
2020-07-08 02:28:08 +00:00
Rick Macklem
022346fa62 Add support for ext_pgs mbufs to nfsrvd_rephead().
This is another in the series of commits that add support to the NFS client
and server for building RPC messages in ext_pgs mbufs with anonymous pages.
This is useful so that the entire mbuf list does not need to be
copied before calling sosend() when NFS over TLS is enabled.

Since ND_EXTPG is never set yet, there is no semantic change at this time.
2020-07-07 00:42:23 +00:00
Rick Macklem
34fc29e0c9 Add support for ext_pgs mbufs to nfsm_strtom().
Also, add a new function nfsm_add_ext_pgs() which will either add a page
or add a new ext_pgs mbuf with a page to the mbuf list. Used by nfsm_strtom().
This is another in the series of commits that add support to the NFS client
and server for building RPC messages in ext_pgs mbufs with anonymous pages.
This is useful so that the entire mbuf list does not need to be
copied before calling sosend() when NFS over TLS is enabled.

Since ND_EXTPG is never set yet, there is no semantic change at this time.
2020-07-05 21:55:16 +00:00
Mateusz Guzik
11c345b18f devfs: fix a vnode use-after-free in devfs_ioctl
The vnode to be replaced was read with a shared lock, meaning 2 racing threads
can find the same one.

While here clean it up a little bit.
2020-07-04 06:27:28 +00:00
Rick Macklem
dccb580624 Add support for ext_pgs mbufs to nfscl_reqstart() and nfsm_set().
This is another in the series of commits that add support to the NFS client
and server for building RPC messages in ext_pgs mbufs with anonymous pages.
This is useful so that the entire mbuf list does not need to be
copied before calling sosend() when NFS over TLS is enabled.

Since ND_EXTPG is never set yet, there is no semantic change at this time.
2020-07-04 03:28:13 +00:00
Rick Macklem
606007409c Fix build breakage caused by r362903. Only pmap.h is needed now, but
vm_page.h and vm_pageout.h is needed later, so put them in now.

Pointy hat goes on me.
2020-07-03 05:21:05 +00:00
Rick Macklem
2da1527844 Add support for ext_pgs mbufs to nfsm_build().
This is the first of a series of commits that add support to the NFS client
and server for building RPC messages in ext_pgs mbufs with anonymous pages.
This is useful so that the entire mbuf list does not need to be
copied before calling sosend() when NFS over TLS is enabled.

Since ND_EXTPG is never set yet, there is no semantic change at this time.
2020-07-03 01:19:29 +00:00
Rick Macklem
4476c1def0 Add a boolean argument to nfscl_reqstart() to indicate that ext_pgs mbufs
should be used.

For KERN_TLS (and possibly some other future network interface) the mbuf
list passed into sosend() must be ext_pgs mbufs. The krpc could simply
copy all the mbuf data into ext_pgs mbufs before calling sosend(), but
that would be inefficient for large RPC messages.
This patch adds an argument to nfscl_reqstart() to indicate that it should
fill the RPC message into ext_pgs mbufs.
It also adds fields to "struct nfsrv_descript" needed for building NFS RPC
messages in ext_pgs mbufs, along with new flags for this.

Since the argument is always "false", this commit should not result in any
semantic change. However, this commit prepares the code
for future commits that will add support for building of NFS RPC messages
in ext_pgs mbufs.
2020-06-26 03:11:54 +00:00
Mark Johnston
84242cf68a Call swap_pager_freespace() from vm_object_page_remove().
All vm_object_page_remove() callers, except
linux_invalidate_mapping_pages() in the LinuxKPI, free swap space when
removing a range of pages from an object.  The LinuxKPI case appears to
be an unintentional omission that could result in leaked swap blocks, so
unconditionally free swap space in vm_object_page_remove() to protect
against similar bugs in the future.

Reviewed by:	alc, kib
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D25329
2020-06-25 15:21:21 +00:00
Doug Rabson
c07782e10e Add some missing parts for supporting va_birthtime.
Reviewed by:	rmacklem
2020-06-22 08:23:16 +00:00
Thomas Munro
f270658873 vfs: track sequential reads and writes separately
For software like PostgreSQL and SQLite that sometimes reads sequentially
while also writing sequentially some distance behind with interleaved
syscalls on the same fd, performance is better on UFS if we do
sequential access heuristics separately for reads and writes.

Patch originally by Andrew Gierth in 2008, updated and proposed by me with
his permission.

Reviewed by:	mjg, kib, tmunro
Approved by:	mjg (mentor)
Obtained from:	Andrew Gierth <andrew@tao11.riddles.org.uk>
Differential Revision:	https://reviews.freebsd.org/D25024
2020-06-21 08:51:24 +00:00
Alan Somers
eea79fde5a Remove vfs_statfs and vnode_mount macros from NFS
These macro definitions are no longer needed as the NFS OSX port is long
dead.  The vfs_statfs macro conflicts with the vfsops field of the same
name.

Submitted by:	shivank@
Reviewed by:	rmacklem
MFC after:	2 weeks
Sponsored by:	Google, Inc. (GSoC 2020)
Differential Revision:	https://reviews.freebsd.org/D25263
2020-06-17 16:20:19 +00:00
Doug Rabson
3900c11481 Add support for the timecreate attribute
This maps to the va_birthtime VFS attribute.
2020-06-14 11:41:57 +00:00
Rick Macklem
1f7104d720 Fix export_args ex_flags field so that is 64bits, the same as mnt_flags.
Since mnt_flags was upgraded to 64bits there has been a quirk in
"struct export_args", since it hold a copy of mnt_flags
in ex_flags, which is an "int" (32bits).
This happens to currently work, since all the flag bits used in ex_flags are
defined in the low order 32bits. However, new export flags cannot be defined.
Also, ex_anon is a "struct xucred", which limits it to 16 additional groups.
This patch revises "struct export_args" to make ex_flags 64bits and replaces
ex_anon with ex_uid, ex_ngroups and ex_groups (which points to a
groups list, so it can be malloc'd up to NGROUPS in size.
This requires that the VFS_CHECKEXP() arguments change, so I also modified the
last "secflavors" argument to be an array pointer, so that the
secflavors could be copied in VFS_CHECKEXP() while the export entry is locked.
(Without this patch VFS_CHECKEXP() returns a pointer to the secflavors
array and then it is used after being unlocked, which is potentially
a problem if the exports entry is changed.
In practice this does not occur when mountd is run with "-S",
but I think it is worth fixing.)

This patch also deleted the vfs_oexport_conv() function, since
do_mount_update() does the conversion, as required by the old vfs_cmount()
calls.

Reviewed by:	kib, freqlabs
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D25088
2020-06-14 00:10:18 +00:00
Ryan Moeller
693d10a291 tmpfs: Preserve alignment of struct fid fields
On 64-bit platforms, the two short fields in `struct tmpfs_fid` are padded to
the 64-bit alignment of the long field.  This pushes the offsets of the
subsequent fields by 4 bytes and makes `struct tmpfs_fid` bigger than
`struct fid`.  `tmpfs_vptofh()` casts a `struct fid *` to `struct tmpfs_fid *`,
causing 4 bytes of adjacent memory to be overwritten when the struct fields are
set.  Through several layers of indirection and embedded structs, the adjacent
memory for one particular call to `tmpfs_vptofh()` happens to be the stack
canary for `nfsrvd_compound()`.  Half of the canary ends up being clobbered,
going unnoticed until eventually the stack check fails when `nfsrvd_compound()`
returns and a panic is triggered.

Instead of duplicating fields of `struct fid` in `struct tmpfs_fid`, narrow the
struct to cover only the unique fields for tmpfs and assert at compile time
that the struct fits in the allotted space.  This way we don't have to
replicate the offsets of `struct fid` fields, we just use them directly.

Reviewed by:	kib, mav, rmacklem
Approved by:	mav (mentor)
MFC after:	1 week
Sponsored by:	iXsystems, Inc.
Differential Revision:	https://reviews.freebsd.org/D25077
2020-06-03 09:38:51 +00:00
Alexander V. Chernikov
9d5df78e64 Fix NOINET6 build broken by r361575.
Reported by:	ci, hps
2020-05-28 09:52:28 +00:00
Alexander V. Chernikov
c74ce5cca3 Make NFS address selection use fib4_lookup().
fib4_lookup_nh_ represents pre-epoch generation of fib api,
providing less guarantees over pointer validness and requiring
on-stack data copying.
Switch call to use new fib4_lookup(), allowing to eventually
deprecate old api.

Differential Revision:	https://reviews.freebsd.org/D24977
2020-05-28 07:35:07 +00:00
Conrad Meyer
852c303b61 copystr(9): Move to deprecate (attempt #2)
This reapplies logical r360944 and r360946 (reverting r360955), with fixed
copystr() stand-in replacement macro.  Eventually the goal is to convert
consumers and kill the macro, but for a first step it helps if the macro is
correct.

Prior commit message:

Unlike the other copy*() functions, it does not serve to copy from one
address space to another or protect against potential faults.  It's just
an older incarnation of the now-more-common strlcpy().

Add a coccinelle script to tools/ which can be used to mechanically
convert existing instances where replacement with strlcpy is trivial.
In the two cases which matched, fuse_vfsops.c and union_vfsops.c, the
code was further refactored manually to simplify.

Replace the declaration of copystr() in systm.h with a small macro
wrapper around strlcpy (with correction from brooks@ -- thanks).

Remove N redundant MI implementations of copystr.  For MIPS, this
entailed inlining the assembler copystr into the only consumer,
copyinstr, and making the latter a leaf function.

Reviewed by:		jhb (earlier version)
Discussed with:		brooks (thanks!)
Differential Revision:	https://reviews.freebsd.org/D24672
2020-05-25 16:40:48 +00:00
Alexander V. Chernikov
2bbab0af6d Use epoch(9) for rtentries to simplify control plane operations.
Currently the only reason of refcounting rtentries is the need to report
 the rtable operation details immediately after the execution.
Delaying rtentry reclamation allows to stop refcounting and simplify the code.
Additionally, this change allows to reimplement rib_lookup_info(), which
 is used by some of the customers to get the matching prefix along
 with nexthops, in more efficient way.

The change keeps per-vnet rtzone uma zone. It adds nh_vnet field to
 nhop_priv to be able to reliably set curvnet even during vnet teardown.
Rest of the reference counting code will be removed in the D24867 .

Differential Revision:	https://reviews.freebsd.org/D24866
2020-05-23 10:21:02 +00:00
Alan Somers
bfcb817bcd Fix issues with FUSE_ACCESS when default_permissions is disabled
This patch fixes two issues relating to FUSE_ACCESS when the
default_permissions mount option is disabled:

* VOP_ACCESS() calls with VADMIN set should never be sent to a fuse server
  in the form of FUSE_ACCESS operations. The FUSE protocol has no equivalent
  of VADMIN, so we must evaluate such things kernel-side, regardless of the
  default_permissions setting.

* The FUSE protocol only requires FUSE_ACCESS to be sent for two purposes:
  for the access(2) syscall and to check directory permissions for
  searchability during lookup. FreeBSD sends it much more frequently, due to
  differences between our VFS and Linux's, for which FUSE was designed. But
  this patch does eliminate several cases not required by the FUSE protocol:

  * for any FUSE_*XATTR operation
  * when creating a new file
  * when deleting a file
  * when setting timestamps, such as by utimensat(2).

* Additionally, when default_permissions is disabled, this patch removes one
  FUSE_GETATTR operation when deleting a file.

PR:		245689
Reported by:	MooseFS FreeBSD Team <freebsd@moosefs.pro>
Reviewed by:	cem
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D24777
2020-05-22 18:11:17 +00:00
Alan Somers
7096c29e5b Disable nullfs cacheing on top of fusefs
Nullfs cacheing can keep a large number of vnodes active.  That results in
more active FUSE file handles, causing some FUSE servers to use extra
resources.  Disable nullfs cacheing for fusefs, just like we already do for
NFSv4.

PR:		245688
Reported by:	MooseFS FreeBSD Team <freebsd@moosefs.pro>
MFC after:	2 weeks
2020-05-22 18:03:14 +00:00
Ryan Moeller
245bfd34da Deduplicate fsid comparisons
Comparing fsid_t objects requires internal knowledge of the fsid structure
and yet this is duplicated across a number of places in the code.

Simplify by creating a fsidcmp function (macro).

Reviewed by:	mjg, rmacklem
Approved by:	mav (mentor)
MFC after:	1 week
Sponsored by:	iXsystems, Inc.
Differential Revision:	https://reviews.freebsd.org/D24749
2020-05-21 01:55:35 +00:00
Rick Macklem
3d7650f04c Add a function nfsm_set() to initialize "struct nfsrv_descript" for building
mbuf lists.

This function is currently trivial, but will that will change when
support for building NFS messages in ext_pgs mbufs is added.
Adding support for ext_pgs mbufs is needed for KERN_TLS, which will
be used to implement nfs-over-tls.
2020-05-18 00:07:45 +00:00
Fedor Uporov
cd3acfe7f3 Add BE architectures support.
Author of most initial version: pfg (https://reviews.freebsd.org/D23259)

Reviewed by:    pfg
MFC after:      3 months

Differential Revision:    https://reviews.freebsd.org/D24685
2020-05-17 14:52:54 +00:00
Fedor Uporov
4bd6d63dc5 Restrict the max runp and runb return values in case of extents mapping.
This restriction already present in case of indirect mapping, do the same
in case of extents.

PR:		246182
Reported by:	Teran McKinney
MFC after:	2 weeks
2020-05-17 14:10:46 +00:00
Fedor Uporov
86e2d48bf9 Fix incorrect inode link count check in case of rename.
The check was incorrect because the directory inode link count have
min value 2 after dir_nlink extfs feature introduction.
2020-05-17 14:03:13 +00:00
Fedor Uporov
ec81c9cc06 Add inode bitmap tail initialization.
Make ext2fs compatible with changes introduced in e2fsprogs v1.45.2.
Now the tail of inode bitmap is filled with 0xff pattern explicitly during
bitmap initialization phase to avoid e2fsck error like:
"Padding at end of inode bitmap is not set."
2020-05-17 14:00:54 +00:00
John Baldwin
07a34ce381 Remove unused header for DES.
The NFS port doesn't use any of the DES functions.
2020-05-13 18:35:02 +00:00
Ryan Moeller
b9cc3262bc nfs: Remove APPLESTATIC macro
It is no longer useful.

Reviewed by:	rmacklem
Approved by:	mav (mentor)
MFC after:	1 week
Sponsored by:	iXsystems, Inc.
Differential Revision:	https://reviews.freebsd.org/D24811
2020-05-12 13:23:25 +00:00
Conrad Meyer
051fc58cb3 Revert r360944 and r360946 until reported issues can be resolved
Reported by:	cy
2020-05-12 04:34:26 +00:00
Conrad Meyer
580744621f copystr(9): Move to deprecate [2/2]
Unlike the other copy*() functions, it does not serve to copy from one
address space to another or protect against potential faults.  It's just
an older incarnation of the now-more-common strlcpy().

Add a coccinelle script to tools/ which can be used to mechanically
convert existing instances where replacement with strlcpy is trivial.
In the two cases which matched, fuse_vfsops.c and union_vfsops.c, the
code was further refactored manually to simplify.

Replace the declaration of copystr() in systm.h with a small macro
wrapper around strlcpy.

Remove N redundant MI implementations of copystr.  For MIPS, this
entailed inlining the assembler copystr into the only consumer,
copyinstr, and making the latter a leaf function.

Reviewed by:	jhb
Differential Revision:	https://reviews.freebsd.org/D24672
2020-05-11 22:57:21 +00:00
Alan Somers
9d4e48aebf fusefs: better dtrace probes for asynchronous invalidation operations
MFC after:	2 weeks
2020-05-08 22:26:52 +00:00
Ryan Moeller
32033b3d30 Remove APPLEKEXT ifndefs
They are no longer useful.

Reviewed by:	rmacklem
Approved by:	mav (mentor)
MFC after:	1 week
Sponsored by:	iXsystems, Inc.
Differential Revision:	https://reviews.freebsd.org/D24752
2020-05-08 14:39:38 +00:00
Rick Macklem
04d6c514b0 Delete unused function newnfs_trimleading.
The NFS function called newnfs_trimleading() has not been used by the
code in long time. To give you a clue, it still had a K&R style function
declaration.
Delete it, since it is just cruft, as a part of the NFS mbuf handling
cleanup in preparation for adding ext_pgs mbuf support.
The ext_pgs mbuf support for the build/send side is needed by
nfs-over-tls.
2020-05-06 00:44:03 +00:00
Rick Macklem
3973ef1dfc Revert r360514, to avoid unnecessary churn of the sources.
r360514 prepared the NFS code for changes to handle ext_pgs mbufs on
the receive side. However, at this time, KERN_TLS does not pass
ext_pgs mbufs up through soreceive(). As such, as this time, only
the send/build side of the NFS mbuf code needs to handle ext_pgs mbufs.
Revert r360514 since the rather extensive changes required for receive
side ext_pgs mbufs are not yet needed.
This avoids unnecessary churn of the sources.
2020-05-05 00:58:03 +00:00
Rick Macklem
0c9cd5cacd Factor some code out of nfsm_dissct() into separate functions.
Factoring some of the code in nfsm_dissct() out into separate functions
allows these functions to be used elsewhere in the NFS mbuf handling code.
Other uses of these functions will be done in future commits.
It also makes it easier to add support for ext_pgs mbufs, which is needed
for nfs-over-tls under development in base/projects/nfs-over-tls.

Although the algorithm in nfsm_dissct() is somewhat re-written by this
patch, the semantics of nfsm_dissct() should not have changed.
2020-05-01 00:36:14 +00:00
Rick Macklem
5ecf33c6c4 Get rid of uio_XXX macros used for the Mac OS/X port.
The NFS code had a bunch of Mac OS/X accessor functions named uio_XXX
left over from the port to Mac OS/X. Since that port is long forgotten,
replace the calls with the code generated by the FreeBSD macros for these
in nfskpiport.h. This allows the macros to be deleted from nfskpiport.h
and I think makes the code more readable.

This patch should not result in any semantic change.
2020-04-28 02:11:02 +00:00
Mark Johnston
9b22722423 Call pipeselwakeup() after toggling PIPE_EOF.
This ensures that pipe_poll() and the pipe kqueue filters observe
PIPE_EOF and set EV_EOF accordingly.  As a result an extra call to
knote() after setting PIPE_EOF is unnecessary.

Submitted by:	Jan Kokemüller <jan.kokemueller@gmail.com>
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D24528
2020-04-27 15:59:07 +00:00
Rick Macklem
e4a458bb1b Remove Mac OS/X macros that did nothing for FreeBSD.
The macros CAST_USER_ADDR_T() and CAST_DOWN() were used for the Mac OS/X
port. The first of these macros was a no-op for FreeBSD and the second
is no longer used.
This patch gets rid of them. It also deletes the "mbuf_t" typedef which
is no longer used in the FreeBSD code from nfskpiport.h

This patch should not change semantics.
2020-04-25 02:18:59 +00:00
Rick Macklem
897d7d45ba Make the NFSv4.n client's recovery from NFSERR_BADSESSION RFC5661 conformant.
RFC5661 specifies that a client's recovery upon receipt of NFSERR_BADSESSION
should first consist of a CreateSession operation using the extant ClientID.
If that fails, then a full recovery beginning with the ExchangeID operation
is to be done.
Without this patch, the FreeBSD client did not attempt the CreateSession
operation with the extant ClientID and went directly to a full recovery
beginning with ExchangeID. I have had this patch several years, but since
no extant NFSv4.n server required the CreateSession with extant ClientID,
I have never committed it.
I an committing it now, since I suspect some future NFSv4.n server will
require this and it should not negatively impact recovery for extant NFSv4.n
servers, since they should all return NFSERR_STATECLIENTID for this first
CreateSession.

The patched client has been tested for recovery against both the FreeBSD
and Linux NFSv4.n servers and no problems have been observed.

MFC after:	1 month
2020-04-22 21:00:14 +00:00
Edward Tomasz Napierala
d499502db7 Silence down a warning which should really be a debug message.
MFC after:	2 weeks
Sponsored by:	DARPA
2020-04-21 13:57:51 +00:00
Rick Macklem
ae070589d3 Replace all instances of the typedef mbuf_t with "struct mbuf *".
The typedef mbuf_t was used for the Mac OS/X port of the code long ago.
Since this port is no longer used and the use of mbuf_t obscures what
the code does (and is not consistent with style(9)), it is no longer needed.
This patch replaces all instances of mbuf_t with "struct mbuf *", so that
it is no longer used.

This patch should not result in any semantic change.
2020-04-17 21:17:51 +00:00
Rick Macklem
82164bdd76 Add a sanity check for nes_numsecflavor to the NFS server.
Ryan Moeller reported crashes in the NFS server that appear to be
caused by stack corruption in nfsrv_compound(). It appears that
the stack got corrupted just after a NFSv4.1 Lookup that crosses
a server mount point.
Although it is just a "theory" at this point, the most obvious way
the stack could get corrupted would be if nfsvno_checkexp() somehow
acquires an export with a bogus nes_numsecflavor value. This would
cause the copying of the secflavors to run off the end of the array,
which is allocated on the stack below where the corruption occurs.

This sanity check is simple to do and would stop the stack corruption
if the theory is correct. Otherwise, doing the sanity check seems to
be a reasonable safety belt to add to the code.

Reported by:	freqlabs
MFC after:	2 weeks
2020-04-17 02:21:46 +00:00