Commit Graph

215 Commits

Author SHA1 Message Date
Conrad Meyer
b97b91b547 nfs: Remove NFSSOCKADDRALLOC, NFSSOCKADDRFREE macros
They were just thin wrappers over malloc(9) w/ M_ZERO and free(9).

Discussed with:	rmacklem, markj
Sponsored by:	Dell EMC Isilon
2018-01-25 22:38:39 +00:00
Conrad Meyer
222daa421f style: Remove remaining deprecated MALLOC/FREE macros
Mechanically replace uses of MALLOC/FREE with appropriate invocations of
malloc(9) / free(9) (a series of sed expressions).  Something like:

* MALLOC(a, b, ... -> a = malloc(...
* FREE( -> free(
* free((caddr_t) -> free(

No functional change.

For now, punt on modifying contrib ipfilter code, leaving a definition of
the macro in its KMALLOC().

Reported by:	jhb
Reviewed by:	cy, imp, markj, rmacklem
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D14035
2018-01-25 22:25:13 +00:00
John Baldwin
b1288166e0 Use long for the last argument to VOP_PATHCONF rather than a register_t.
pathconf(2) and fpathconf(2) both return a long.  The kern_[f]pathconf()
functions now accept a pointer to a long value rather than modifying
td_retval directly.  Instead, the system calls explicitly store the
returned long value in td_retval[0].

Requested by:	bde
Reviewed by:	kib
Sponsored by:	Chelsio Communications
2018-01-17 22:36:58 +00:00
Alexander Kabaev
151ba7933a Do pass removing some write-only variables from the kernel.
This reduces noise when kernel is compiled by newer GCC versions,
such as one used by external toolchain ports.

Reviewed by: kib, andrew(sys/arm and sys/arm64), emaste(partial), erj(partial)
Reviewed by: jhb (sys/dev/pci/* sys/kern/vfs_aio.c and sys/kern/kern_synch.c)
Differential Revision: https://reviews.freebsd.org/D10385
2017-12-25 04:48:39 +00:00
John Baldwin
5538424353 Replace one more LINK_MAX with NFS_LINK_MAX missed in r326991.
Sponsored by:	Chelsio Communications
2017-12-19 22:43:39 +00:00
John Baldwin
a0a073b16d Update NFS to handle larger link counts post ino64.
- Define a NFS_LINK_MAX as UINT32_MAX to match the wire protocol.
- Use NFS_LINK_MAX instead of LINK_MAX as the fallback value reported
  for a PATHCONF RPC by the NFS server.
- Use NFS_LINK_MAX instead of LINK_MAX as the default value reported
  by the NFS client pathconf() if not overridden by the NFS server.
- When reading the link count out of an RPC reply, read the full 32
  bits instead of the lower 16 bits.

Reviewed by:	rmacklem (earlier version)
Sponsored by:	Chelsio Communications
2017-12-19 19:18:48 +00:00
Rick Macklem
219afc4fe2 Define macros used by the pNFS server code.
This commit defines some macros used by the pNFS server code.
They will not be used until the main pNFS server code merge occurs,
which will probably be in April 2018.
2017-12-09 21:04:56 +00:00
Pedro F. Giffuni
d63027b668 sys/fs: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 15:15:37 +00:00
Pedro F. Giffuni
51369649b0 sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00
Rick Macklem
f49c813c1d Use taskqueue(9) to do writes/commits to mirrored DSs concurrently.
When the NFSv4.1 pNFS client is using a Flexible File Layout specifying
mirrored Data Servers, it must do the writes and commits to all mirrors.
This patch modifies the client to use a taskqueue to perform these writes
and commits concurrently.
The number of threads can't be changed for taskqueue(9), so it is set
to 4 * mp_ncpus by default, but this can be overridden by setting the
sysctl vfs.nfs.pnfsiothreads.

Differential Revision:	https://reviews.freebsd.org/D12632
2017-10-16 23:28:12 +00:00
Rick Macklem
63918d3848 Fix forced dismount when a pNFS mount is hung on a DS.
When a "pnfs" NFSv4.1 mount is hung because of an unresponsive DS,
a forced dismount wouldn't work, because the RPC socket for the DS
was not being closed. This patch fixes this.
This will only affect "pnfs" mounts where the pNFS server's DS
is unresponsive (crashed or network partitioned or...).
Found during testing of the pNFS server.

MFC after:	2 weeks
2017-10-10 21:05:40 +00:00
Rick Macklem
b949cc41d1 Add Flex File Layout support to the NFSv4.1 pNFS client.
This patch adds support for the Flexible File Layout to the pNFS client.
Although the patch is rather large, it should only affect NFS mounts
using the "pnfs" option against pNFS servers that do not support File
Layout.
There are still a couple of things missing from the Flexible File Layout
client implementation:
- The code does not yet do a LayoutReturn with I/O error stats when
  I/O error(s) occur when attempting to do I/O on a DS.
  This will be fixed in a future commit, since it is important for the
  MDS to know that I/O on a DS is failing.
- The current code does writes and commits to mirror DSs serially.
  Making them happen concurrently will be done in a future commit,
  after discussion on freebsd-current@ on the best way to do this.
- The code does not handle NFSv4.0 DSs. Since there is no extant pNFS
  server that implements NFSv4.0 DSs and NFSv4.1 DSs makes more sense
  now, I don't intend to implement this until there is a need for it.
  There is support for NFSv4.1 and NFSv3 DSs.
2017-10-05 20:10:40 +00:00
Rick Macklem
64059dce60 Add a few definitions for the Flex File Layout.
This patch adds a few definitions for the Flex File Layout.
Until a future commit adds Flex File layout support, these new fields
are not used.
This patch should not affect the "pnfs" option for File Layout.
2017-10-04 22:55:30 +00:00
Rick Macklem
efea6b20b9 Add support for Flex File Layout to the pNFS client structures.
This patch modifies the pNFS client layout and deviceinfo structures
to add fields and unions for the Flex File Layout. Until a future
commit adds Flex File layout support, these new fields are not used.
This patch should not affect the "pnfs" option for File Layout.
2017-09-29 23:13:01 +00:00
Rick Macklem
8dd62f2eaa Add the NFS client state flag that enables Flexible File Layout.
This patch adds a NFSSTA_FLEXFILE flag that will be used to enable
Flexible File Layout for the NFSv4.1 pNFS client. It is not yet
used, but will be after a future commit adds Flex File Layout support.
2017-09-28 23:05:08 +00:00
Rick Macklem
be3d32ad6e Change nfsv4_getipaddr() and nfsrpc_fillsa() to not use sockaddr_storage.
This patch changes nfsv4_getipaddr() and nfsrpc_fillsa() to use
a sockaddr_in * and sockaddr_in6 * instead of sockaddr_storage, to
avoid allocating the latter on the stack. It also moves the nfsrpc_fillsa()
call to after the completion of parsing of the DeviceInfo reply from
the server. This patch is in preparation for addition of Flex File
Layout support in a future commit.
It only affects the "pnfs" NFSv4.1 client mount option and should not
have changed its semantics.
2017-09-28 22:33:01 +00:00
Rick Macklem
a8462c582c Add major and minor version arguments to nfscl_reqstart().
This patch adds "vers" and "minorvers" arguments to nfscl_reqstart().
The patch always passes them in as "0" and that implies no change
in semantics. These arguments will be used by a future commit that
adds support for the Flexible File Layout.
2017-09-26 23:42:44 +00:00
Rick Macklem
6b43e06029 Add a few definitions for Flex File Layout for pNFS.
These definitions will be used by a future commit.
2017-09-21 00:41:12 +00:00
Rick Macklem
0f29b8292d Make the nfsrpc_layoutget() function a static.
Make the NFSv4 pNFS client function nfsrpc_layoutget() a static, since it
is only used in sys/fs/nfsclient/nfs_clrpcops.c.
This prepares the code for future patches that add Flex File layout
support.
2017-09-19 23:28:22 +00:00
Rick Macklem
2742a21091 Add a new function called nfsm_uiombuflist(), similar to nfsm_uiombuf().
This patch adds a new function called nfsm_uiombuflist(), which is
similar to nfsm_uiombuf(), but doesn't not use the fields in
struct nfsrv_descript. This new function will be used by the pNFS client
for writing to mirrors using Flex Files layout.
The function is not yet called anywhere.
Also, get rid of #ifndef APPLE, which is ancient cruft left over from
the Mac OSX port of the NFSv4 client.
2017-09-19 21:31:36 +00:00
Rick Macklem
b0932afacc Simplify nfsrpc_layoutreturn() args.
Simplify nfsrpc_layoutreturn() args. in preparation for the addition
of Flex File layout support, since File layout uses a 0 length field.
Flex Files does use a longer field, but that will be added in a
subsequent commit.
2017-09-19 20:45:25 +00:00
Rick Macklem
ab118d04be Simplify nfsrpc_layoutcommit() args.
Simplify nfsrpc_layoutcommit() args. in preparation for the addition
of Flex File layout support, since it also uses a 0 length field.
2017-09-19 20:18:41 +00:00
Rick Macklem
47cbff34fa Add kernel support for the NFS client forced dismount "umount -N" option.
When an NFS mount is hung against an unresponsive NFS server, the "umount -f"
option can be used to dismount the mount. Unfortunately, "umount -f" gets
hung as well if a "umount" without "-f" has already been done. Usually,
this is because of a vnode lock being held by the "umount" for the mounted-on
vnode.
This patch adds kernel code so that a new "-N" option can be added to "umount",
allowing it to avoid getting hung for this case.
It adds two flags. One indicates that a forced dismount is about to happen
and the other is used, along with setting mnt_data == NULL, to handshake
with the nfs_unmount() VFS call.
It includes a slight change to the interface used between the client and
common NFS modules, so I bumped __FreeBSD_version to ensure both modules are
rebuilt.

Tested by:	pho
Reviewed by:	kib
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D11735
2017-07-29 19:52:47 +00:00
Rick Macklem
16f300fa4a Replace the checks for MNTK_UNMOUNTF with a macro that does the same thing.
This patch defines a macro that checks for MNTK_UNMOUNTF and replaces
explicit checks with this macro. It has no effect on semantics, but
prepares the code for a future patch where there will also be a
NFS specific flag for "forced dismount about to occur".

Suggested by:	kib
MFC after:	2 weeks
2017-07-27 20:55:31 +00:00
Edward Tomasz Napierala
1d2fef9b9a Rename vfs.nfsd.enable_uidtostring to vfs.nfs.enable_uidtostring.
It applies to both NFS client and NFS server, and is useful for both.
This is different from vfs.nfsd.enable_stringtouid, which is specific
to server side.

Reviewed by:	rmacklem@
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2017-07-19 09:59:32 +00:00
Rick Macklem
25d694a6fa Add support for AF_LOCAL socket upcalls to the nfsuserd daemon.
This patch adds support for AF_LOCAL socket upcalls to an nfsuserd daemon
that supports them. A future patch to the nfsuserd daemon will use AF_LOCAL
sockets to avoid a problem when using upcalls to 127.0.0.1 if jails are
in use.

Suggested by:	dfr
PR:		205193
2017-07-06 00:53:12 +00:00
Edward Tomasz Napierala
3c264086aa Revert part of r320359, as suggested by rmacklem@. That case is only used
for nfsuserd -manage-gids and shouldn't depend on sysctl.

MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
2017-06-27 15:14:06 +00:00
Edward Tomasz Napierala
6a3450e178 Add vfs.nfsd.nfsd_enable_uidtostring, which works just like
vfs.nfsd.nfsd_enable_stringtouid, but in reverse - when set to 1,
it forces the NFSv4 server to return numeric UIDs and GIDs instead
of "user@domain" strings. This helps with clients that can't
translate returned identifiers, eg when rerooting.

The same can be achieved by just never running nfsuserd(8),
but the sysctl is useful to toggle the behaviour back and forth
without rebooting.

Reviewed by:	rmacklem (earlier version)
MFC after:	2 weeks
Sponsored by:	DARPA, AFRL
Differential Revision:	https://reviews.freebsd.org/D11326
2017-06-26 13:11:21 +00:00
Rick Macklem
81b07aac10 Add support to the NFSv4.1/pNFS client for commits through the DS.
A NFSv4.1/pNFS server using File Layout can specify that Commit operations
are to be done against the DS instead of MDS. Since no extant pNFS
server did this, the code was untested and "#ifdef notyet".
The FreeBSD pNFS server I am developing does specify that Commits be done
through the DS, so the code has been enabled/tested.
This patch should only affect the case of a pNFS server that specfies
Commits through the DS.

PR:		219551
MFC after:	2 weeks
2017-06-26 00:43:04 +00:00
Rick Macklem
a351e99ce6 Add two new compound RPCs to the NFSv4.1/pNFS client.
When the NFSv4.1 client is doing pNFS, it needs to get an Open and
a Layout for every file it will be doing I/O on. The current code
does two separate RPCs to get these. This patch adds two new compounds
that do the both the Open and LayoutGet in the same RPC, reducing the
RPC count.
It also factors out the code that sets up and parses the LayoutGet operation
into separate functions, so that the code doesn't get duplicated for
these new RPCs.
This patch is fairly large, but should only affect the NFSv4.1 client
when the "pnfs" option is specified.

PR:		219550
MFC after:	2 weeks
2017-06-24 20:01:21 +00:00
Rick Macklem
ee791357a2 Add the definition of maxbcachebuf to sys/buf.h.
r320070 removed the definition of maxbcachebuf from sys/param.h to
fix the build for arm.
This patch adds the definition of maxbcachebuf to sys/buf.h, which
should be ok, since sys/buf.h is not being included in arm/arm/elf_note.S.

Suggested by:	kib
MFC after:	2 weeks
2017-06-19 22:07:53 +00:00
Rick Macklem
95ac7f1a74 Fix the NFS client/server so that it actually uses the 64bit ino_t filenos.
The code still doesn't use d_off. That will come in a future commit.
The code also removes the checks for servers returning a fileno that
doesn't fit in 32bits, since that should work ok now.
Bump __FreeBSD_version since this patch changes the interface between
the NFS kernel modules.

Reviewed by:	kib
2017-06-18 21:48:31 +00:00
Rick Macklem
1d9f01b18e Take "extern int maxbcachebuf" out of sys/param.h, since it breaks the
arm build.

In the arm build, elf_note.S includes sys/param.h and then does an
elf macro called ELFNOTE(). Although the compile error doesn't make
sense to me, I believe it just means that an "extern ..." can't exist
in param.h for this inclusion case.
I suspect adding #if !defined(LOCORE) might fix the build, but this
commit just takes the definition out.
I will ask freebsd-current@ what is the best was to deal with this
and do a subsequent commit after that.

Reported by:	melounmichal@gmail.com
2017-06-18 12:28:43 +00:00
Rick Macklem
d1c5e240a8 Make MAXBCACHEBUF a tunable called vfs.maxbcachebuf.
By making MAXBCACHEBUF a tunable, it can be increased to allow for
larger read/write data sizes for the NFS client.
The tunable is limited to MAXPHYS, which is currently 128K.
Making MAXPHYS a tunable or increasing its value is being discussed,
since it would be nice to support a read/write data size of 1Mbyte
for the NFS client when mounting the AmazonEFS file service.

Reviewed by:	kib
MFC after:	2 weeks
Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D10991
2017-06-17 22:24:19 +00:00
Rick Macklem
6149361b1e Define NFS_MAXXDR as the upper bound on XDR overhead in an NFS RPC.
This definition is a part of the maxiotune2 patch that will be
committed soon. It is being committed separately to ease merging
with the pNFS projects subversion trees.

MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D10991
2017-06-12 23:41:20 +00:00
Konstantin Belousov
6992112349 Commit the 64-bit inode project.
Extend the ino_t, dev_t, nlink_t types to 64-bit ints.  Modify
struct dirent layout to add d_off, increase the size of d_fileno
to 64-bits, increase the size of d_namlen to 16-bits, and change
the required alignment.  Increase struct statfs f_mntfromname[] and
f_mntonname[] array length MNAMELEN to 1024.

ABI breakage is mitigated by providing compatibility using versioned
symbols, ingenious use of the existing padding in structures, and
by employing other tricks.  Unfortunately, not everything can be
fixed, especially outside the base system.  For instance, third-party
APIs which pass struct stat around are broken in backward and
forward incompatible ways.

Kinfo sysctl MIBs ABI is changed in backward-compatible way, but
there is no general mechanism to handle other sysctl MIBS which
return structures where the layout has changed. It was considered
that the breakage is either in the management interfaces, where we
usually allow ABI slip, or is not important.

Struct xvnode changed layout, no compat shims are provided.

For struct xtty, dev_t tty device member was reduced to uint32_t.
It was decided that keeping ABI compat in this case is more useful
than reporting 64-bit dev_t, for the sake of pstat.

Update note: strictly follow the instructions in UPDATING.  Build
and install the new kernel with COMPAT_FREEBSD11 option enabled,
then reboot, and only then install new world.

Credits: The 64-bit inode project, also known as ino64, started life
many years ago as a project by Gleb Kurtsou (gleb).  Kirk McKusick
(mckusick) then picked up and updated the patch, and acted as a
flag-waver.  Feedback, suggestions, and discussions were carried
by Ed Maste (emaste), John Baldwin (jhb), Jilles Tjoelker (jilles),
and Rick Macklem (rmacklem).  Kris Moore (kris) performed an initial
ports investigation followed by an exp-run by Antoine Brodin (antoine).
Essential and all-embracing testing was done by Peter Holm (pho).
The heavy lifting of coordinating all these efforts and bringing the
project to completion were done by Konstantin Belousov (kib).

Sponsored by:	The FreeBSD Foundation (emaste, kib)
Differential revision:	https://reviews.freebsd.org/D10439
2017-05-23 09:29:05 +00:00
Rick Macklem
6406db24cb Make the NFSv4 client to use a write open for reading if allowed by the server.
An NFSv4 server has the option of allowing a Read to be done using a Write
Open. If this is not allowed, the server will return NFSERR_OPENMODE.
This patch attempts the read with a write open and then disables this
if the server replies NFSERR_OPENMODE.
This change will avoid some uses of the special stateids. This will be
useful for pNFS/DS Reads, since they cannot use special stateids.
It will also be useful for any NFSv4 server that does not support reading
via the special stateids. It has been tested against both types of NFSv4 server.

MFC after:	2 weeks
2017-04-23 21:51:28 +00:00
Rick Macklem
0596f343f8 Don't set ND_NOMOREDATA for a failed Setattr operation (NFSv4).
The NFSv4 Setattr operation always has reply data even when it fails,
so don't set the ND_NOMOREDATA for it. This would only affect unusual
cases where Setattr fails and the RPC code wants to parse the rest of
the compound. Detected during recent development related to the pNFS server.

MFC after:	2 weeks
2017-04-21 23:01:32 +00:00
Rick Macklem
40f8ff4800 Don't create a backchannel for a DS connection.
An NFSv4.1 client connection to a Data Server (DS) should not have a
backchannel. This patch fixes the NFSv4.1/pNFS client to not do a backchannel
for this case.
Found during recent testing with the pNFS server under development.

MFC after:	2 weeks
2017-04-21 22:38:26 +00:00
Rick Macklem
8c1d0d9ce5 Set default uid/gid to nobody/nogroup for NFSv4 mapping.
The default uid/gid for NFSv4 are set by the nfsuserd(8) daemon.
However, they were 0 until the nfsuserd(8) was run. Since it is
possible to use NFSv4 without running the nfsuserd(8) daemon, set them
to nobody/nogroup initially.
Without this patch, the values would be set by the nfsuserd(8) daemon
and left changed even if the nfsuserd(8) daemon was killed. The default
values of 0 meant that setting a group to "wheel" would fail even when
done by root.
It also adds a definition of GID_NOGROUP to sys/conf.h.

Discussed on:	freebsd-current@
MFC after:	2 weeks
2017-04-21 20:08:10 +00:00
Rick Macklem
b843ada7aa Revert r317240. I didn't realize there were defined constants for
uid/gid values in sys/conf.h. I will do another commit using those.
2017-04-21 11:48:12 +00:00
Rick Macklem
1350db1780 Set default uid/gid to nobody/nogroup for NFSv4 mapping.
The default uid/gid for NFSv4 are set by the nfsuserd(8) daemon.
However, they were 0 until the nfsuserd(8) was run. Since it is
possible to use NFSv4 without running the nfsuserd(8) daemon, set them
to nobody/nogroup initially.
Without this patch, the values would be set by the nfsuserd(8) daemon
and left changed even if the nfsuserd(8) daemon was killed. Also, the default
values of 0 meant that setting a group to "wheel" would fail even when
done by root and this patch fixes this issue.

MFC after:	2 weeks
2017-04-21 01:50:41 +00:00
Rick Macklem
6d4377c1ae Remove unused "cred" argument to ncl_flush().
The "cred" argument of ncl_flush() is unused and it was confusing to have
the code passing in NULL for this argument in some cases. This patch deletes
this argument.
There is no semantic change because of this patch.

MFC after:	2 weeks
2017-04-14 13:25:45 +00:00
Rick Macklem
037a2012e9 Add an NFSv4.1 mount option for "use one openowner".
Some NFSv4.1 servers such as AmazonEFS can only support a small fixed number
of open_owner4s. This patch adds a mount option called "oneopenown" that
can be used for NFSv4.1 mounts to make the client do all Opens with the
same open_owner4 string. This option can only be used with NFSv4.1 and
may not work correctly when Delegations are is use.

Reported by:	cperciva
Tested by:	cperciva
MFC after:	2 weeks
Differential Revision:	https://reviews.freebsd.org/D8988
2017-04-13 21:54:19 +00:00
Rick Macklem
fb55679151 Set initial values for nfsstatfs in the NFSv4 client.
The AmazonEFS NFSv4.1 server does not support the FILES_FREE and FILES_TOTAL
attributes. As such, an NFSv4.1 mount to the server would return garbage
for these values. This patch initializes the fields of the nfsstatfs structure,
so that "df" and friends will at least return consistent bogus values.
This patch should have effect when mounting other NFSv4.1 servers.

Reported by:	cperciva
MFC after:	2 weeks
2017-04-10 21:49:35 +00:00
Rick Macklem
2242bc81f2 Fix the NFSv4.1 client for NFSERR_BADSESSION recovery via ReclaimComplete.
For the ReclaimComplete operation, the RPC layer should not loop on
NFSERR_BADSESSION. If it does, the recovery thread (nfscl) can get stuck
looping and will not do a recovery.
This patch fixes it so it does not loop. This bug only affects NFSv4.1 and
only when a server reboots.

Tested by:	cperciva
PR:		215886
MFC after:	2 weeks
2017-04-09 21:06:21 +00:00
Warner Losh
fbbd9655e5 Renumber copyright clause 4
Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by:	Jan Schaumann <jschauma@stevens.edu>
Pull Request:	https://github.com/freebsd/freebsd/pull/96
2017-02-28 23:42:47 +00:00
Konstantin Belousov
2f304845e2 Do not allocate struct statfs on kernel stack.
Right now size of the structure is 472 bytes on amd64, which is
already large and stack allocations are indesirable.  With the ino64
work, MNAMELEN is increased to 1024, which will make it impossible to have
struct statfs on the stack.

Extracted from:	ino64 work by gleb
Discussed with:	mckusick
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
2017-01-05 17:19:26 +00:00
Rick Macklem
b2fc0141d9 Fix NFSv4.1 client recovery from NFS4ERR_BAD_SESSION errors.
For most NFSv4.1 servers, a NFS4ERR_BAD_SESSION error is a rare failure
that indicates that the server has lost session/open/lock state.
However, recent testing by cperciva@ against the AmazonEFS server found
several problems with client recovery from this due to it generating this
failure frequently.
Briefly, the problems fixed are:
- If all session slots were in use at the time of the failure, some processes
  would continue to loop waiting for a slot on the old session forever.
- If an RPC that doesn't use open/lock state failed with NFS4ERR_BAD_SESSION,
  it would fail the RPC/syscall instead of initiating recovery and then
  looping to retry the RPC.
- If a successful reply to an RPC for an old session wasn't processed
  until after a new session was created for a NFS4ERR_BAD_SESSION error,
  it would erroneously update the new session and corrupt it.
- The use of the first element of the session list in the nfs mount
  structure (which is always the current metadata session) was slightly
  racey. With changes for the above problems it became more racey, so all
  uses of this head pointer was wrapped with a NFSLOCKMNT()/NFSUNLOCKMNT().
- Although the kernel malloc() usually allocates more bytes than requested
  and, as such, this wouldn't have caused problems, the allocation of a
  session structure was 1 byte smaller than it should have been.
  (Null termination byte for the string not included in byte count.)

There are probably still problems with a pNFS data server that fails
with NFS4ERR_BAD_SESSION, but I have no server that does this to test
against (the AmazonEFS server doesn't do pNFS), so I can't fix these yet.

Although this patch is fairly large, it should only affect the handling
of NFS4ERR_BAD_SESSION error replies from an NFSv4.1 server.
Thanks go to cperciva@ for the extension testing he did to help isolate/fix
these problems.

Reported by:	cperciva
Tested by:	cperciva
MFC after:	3 months
Differential Revision:	https://reviews.freebsd.org/D8745
2016-12-23 23:14:53 +00:00
Rick Macklem
1a2079d936 Stop "nfsstat -z" from clearing counts of NFSv4 state structures.
The "-z" option on nfsstats was erroneously zeroing out the counts
of NFSv4 state structures. These counts will normally go back down
to zero as state is released. When zeroed out by "-z", these counts
can go negative. This patch fixes this problem.

MFC after:	2 weeks
2016-11-25 23:28:09 +00:00