This is only allowed by root and only used by the nfs daemon, which
should not provide an incorrect value. However, it's still good
practice to validate data provided by userland.
PR: 206626
Reported by: CTurt <cturt@hardenedbsd.org>
Reviewed by: rmacklem
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D6201
The ordering of acquisition of the state and session mutexes was
reversed in two cases executed when an NFSv4.1 client created/freed
a session. Since clients will typically do this only when mounting
and dismounting, the likelyhood of causing a deadlock was low but possible.
This can only occur for NFSv4.1 mounts, since the others do not
use sessions.
This was detected while testing the pNFS server/client where the
client crashed during dismounting.
The patch also reorders the unlocks, although that isn't necessary
for correct operation.
MFC after: 2 weeks
the old and new NFS clients. He did a good job of isolating the problem
which was caused by the new NFS client not setting the post write mtime
correctly. The new NFS client code was cloned from the old client, but
was incorrect, because the mtime in the nfs vnode's cache wasn't yet
updated. This patch fixes this problem. The patch also adds missing mutex
locking.
Reported and tested by: bde
MFC after: 2 weeks
* Use standard IPv6 SAS instead of rt->rt_ifa address.
* Make address lookup work for IPv6 LLA.
* Save address into buffer provided by caller instead of using static vars.
Discussed with: rmacklem
This leak was introduced by r291527.
Since the nfscommon.ko module is rarely unloaded, this leak would not
have been much of an issue.
MFC after: 2 weeks
option that will be added to the nfsuserd daemon in a future
commit. It modifies the cache used by NFSv4 for name<-->id
translation (both username/uid and group/gid) to support this.
When "-manage-gids" is set, the server looks up each uid
for the RPC and uses the list of groups cached in the server
instead of the list of groups provided in the RPC request.
The cached group list is acquired for the cache by the nfsuserd
daemon via getgrouplist(3).
This avoids the 16 groups limit for the list in the RPC request.
Since the cache is now used for every RPC when "-manage-gids"
is enabled, the code also modifies the cache to use a separate
mutex for each hash list instead of a single global mutex.
Suggested by: jpaetzel
Tested by: jpaetzel
MFC after: 2 weeks
the name of a filesystem when setting it as the first parameter to the
getnewvnode() function. Most filesystems call getnewvnode from just one
place so can use a literal string as the first parameter. However, NFS
calls getnewvnode from two places, so we create a global constant string
that can be used by the two instances. This change also collapses two
instances of getnewvnode() in the UFS filesystem to a single call.
Reviewed by: kib
Tested by: Peter Holm
(opens, locks, etc) is retained, which I believe is correct behaviour.
However, for NFSv4.1, the server also retained a reference to the xprt
(RPC transport socket structure) for the backchannel. This caused
svcpool_destroy() to not call SVC_DESTROY() for the xprt and allowed
a socket upcall to occur after the mutexes in the svcpool were destroyed,
causing a crash.
This patch fixes the code so that the backchannel xprt structure is
dereferenced just before svcpool_destroy() is called, so the code
does do an SVC_DESTROY() on the xprt, which shuts down the socket upcall.
Tested by: g_amanakis@yahoo.com
PR: 204340
MFC after: 2 weeks
sign on every directory exported via NFSv4 with NFSv4 ACLs enabled.
Reviewed by: rmacklem@
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D3502
No appreciable change in performance was observed after increasing
the sizes of these tables and then testing with a single client.
However, there was an email that indicated high CPU overheads for
a heavily loaded NFSv4 and it is hoped that increasing the sizes
of the hash tables via these tunables might help.
The tables remain the same size by default.
Differential Revision: https://reviews.freebsd.org/D2596
MFC after: 2 weeks
years for head. However, it is continuously misused as the mpsafe argument
for callout_init(9). Deprecate the flag and clean up callout_init() calls
to make them more consistent.
Differential Revision: https://reviews.freebsd.org/D2613
Reviewed by: jhb
MFC after: 2 weeks
largest size for a buffer in the buffer cache. This patch
defines a new constant MAXBCACHEBUF, which is the largest
size for a buffer in the buffer cache. Having a separate
constant allows MAXBCACHEBUF to be set larger than MAXBSIZE
on a per-architecture basis, so that NFS can do larger read/writes
for these architectures. It modifies sys/param.h so that BKVASIZE
can also be set on a per-architecture basis.
A couple of cases where NFS used MAXBSIZE instead of NFS_MAXBSIZE
is fixed as well.
Differential Revision: https://reviews.freebsd.org/D2330
Reviewed by: mav, kib
MFC after: 2 weeks
can perform better when using a 128K read/write data size.
This patch changes NFS_MAXDATA from 64K to 128K so that
clients can use 128K for NFS mounts to allow this.
The patch also renames NFS_MAXDATA to NFS_SRVMAXIO so
that it is clear that it applies to the NFS server side
only. It also avoids a name conflict with the NFS_MAXDATA
defined in rpcsvc/nfs_prot.h, that is used for userland RPC.
Tested by: mav
Reviewed by: mav
MFC after: 2 weeks
in the NFS server; garbage collect now-unused NFSMSIZ() and M_HASCL()
macros. Also garbage collect now-unused versions in headers for the
removed previous NFS client and server.
Reviewed by: rmacklem
Sponsored by: EMC / Isilon Storage Division
which means that the NFSCLIENT and NFSSERVER
kernel options will no longer work. This commit
only removes the kernel components. Removal of
unused code in the user utilities will be done
later. This commit does not include an addition
to UPDATING, but that will be committed in a
few minutes.
Discussed on: freebsd-fs
This assertion was added in r246213 as a guard against corrupted mbufs
arriving from drivers, the key distinguishing factor of said mbufs being
that they had a negative length. Given we're in a while loop specifically
designed to skip over zero-length mbufs, panicking on a zero-length mbuf
seems incorrect.
No objection from: kib
This fix addresses only issues with the pynfs reports, none of these
issues are know to create problems for extant real clients.
Submitted by: Bart Hsiao <bart.hsiao@gmail.com>
Reworked by: myself
Reviewed by: rmacklem
Approved by: rmacklem
Sponsored by: QNAP Systems Inc.
mbuf-initialisation logic that is best left to centralised mbuf utility
code rather than scattered around the kernel.
MFC after: 3 days
Sponsored by: EMC / Isilon Storage Division
It overflows witness.
Shorten the names of some nfs mutexes.
Reported and tested by: pho
No objections from: rmacklem, mav
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
into head. The code is not believed to have any effect
on the semantics of non-NFSv4.1 server behaviour.
It is a rather large merge, but I am hoping that there will
not be any regressions for the NFS server.
MFC after: 1 month
should either accept owner and owner_group strings that are just
the digits of the uid/gid or return NFS4ERR_BADOWNER.
This patch adds a sysctl vfs.nfsd.enable_stringtouid, which can
be set to enable the server w.r.t. accepting numeric string. It
also ensures that NFS4ERR_BADOWNER is returned if numeric uid/gid
strings are not enabled. This fixes the server for recent Linux
nfs4 clients that use numeric uid/gid strings by default.
Reported and tested by: craigyk@gmail.com
MFC after: 2 weeks
attributes. This allows the client to cache directory names
when they are looked up, reducing the Lookup RPC count by
about 40% for software builds.
MFC after: 2 weeks
- Introduce additional hash to group requests by hash of sockref. This
allows to process TCP acknowledgements without looping though all the cache,
and as result allows to do it every time.
- Indroduce additional callbacks to notify application layer about sockets
disconnection. Without this last few requests processed just before socket
disconnection never processed their ACKs and stuck in cache for many hours.
- Implement transport-specific method for tracking reply acknowledgements.
New implementation does not cross multiple stack layers to get the data and
does not have race conditions that previously made some requests stuck
in cache. This could be done more efficiently at sockbuf layer, but that
would broke some KBIs, while I don't know other consumers for it aside NFS.
- Instead of traversing all DRC twice per request, run cleaning only once
per request, and except in some conditions traverse only single hash slot
at a time.
Together this limits NFS DRC growth only to situations of real connectivity
problems. If network is working well, and so all replies are acknowledged,
cache remains almost empty even after hours of heavy load. Without this
change on the same test cache was growing to many thousand requests even
with perfectly working local network.
As another result this reduces CPU time spent on the DRC handling during
SPEC NFS benchmark from about 10% to 0.5%.
Sponsored by: iXsystems, Inc.
when a Getattr for a file is done by a client other than the one that
holds the file's delegation. This would only happen when delegations
are enabled and the problem is fixed by this patch.
MFC after: 1 week
nfsv4_fillattr() as NULLs for the Getattr callback. This caused
nfsv4_fillattr() to not fill in the Change attribute for the reply.
I believe this was a violation of the RFC, but had little effect on
server behaviour. This patch passes a non-NULL p argument to fix this.
MFC after: 1 week
option, unbreak the lock tracing release semantic by embedding
calls to LOCKSTAT_PROFILE_RELEASE_LOCK() direclty in the inlined
version of the releasing functions for mutex, rwlock and sxlock.
Failing to do so skips the lockstat_probe_func invokation for
unlocking.
- As part of the LOCKSTAT support is inlined in mutex operation, for
kernel compiled without lock debugging options, potentially every
consumer must be compiled including opt_kdtrace.h.
Fix this by moving KDTRACE_HOOKS into opt_global.h and remove the
dependency by opt_kdtrace.h for all files, as now only KDTRACE_FRAMES
is linked there and it is only used as a compile-time stub [0].
[0] immediately shows some new bug as DTRACE-derived support for debug
in sfxge is broken and it was never really tested. As it was not
including correctly opt_kdtrace.h before it was never enabled so it
was kept broken for a while. Fix this by using a protection stub,
leaving sfxge driver authors the responsibility for fixing it
appropriately [1].
Sponsored by: EMC / Isilon storage division
Discussed with: rstone
[0] Reported by: rstone
[1] Discussed with: philip
The hang occurred in nfsv4_setsequence() when it couldn't find an
available session slot and is fixed by checking for a forced dismount
in progress and just returning for this case.
MFC after: 1 month
CLNT_CONTROL() would be called on "client" after it was
released via CLNT_RELEASE(). It was unlikely that this
code path gets executed and I have not heard of any problem
report caused by this bug. This patch fixes the code so that
this cannot happen.
MFC after: 2 months
to this event, adding if_var.h to files that do need it. Also, include
all includes that now are included due to implicit pollution via if_var.h
Sponsored by: Netflix
Sponsored by: Nginx, Inc.
DRC for NFS over TCP.
- Increase the size of the hash tables.
- Create a separate mutex for each hash list of the TCP hash table.
- Single thread the code that deletes stale cache entries.
- Add a tunable called vfs.nfsd.tcphighwater, which can be increased
to allow the cache to grow larger, avoiding the overhead of frequent
scans to delete stale cache entries.
(The default value will result in frequent scans to delete stale cache
entries, analagous to what the pre-patched code does.)
- Add a tunable called vfs.nfsd.cachetcp that can be used to disable
DRC caching for NFS over TCP, since the old NFS server didn't DRC cache TCP.
It also adjusts the size of nfsrc_floodlevel dynamically, so that it is
always greater than vfs.nfsd.tcphighwater.
For UDP the algorithm remains the same as the pre-patched code, but the
tunable vfs.nfsd.udphighwater can be used to allow the cache to grow
larger and reduce the overhead caused by frequent scans for stale entries.
UDP also uses a larger hash table size than the pre-patched code.
Reported by: wollman
Tested by: wollman (earlier version of patch)
Submitted by: ivoras (earlier patch)
Reviewed by: jhb (earlier version of patch)
MFC after: 1 month
the attribute bitmap argument would be non-zero. This caused an
interoperability problem for a recent patch to the Linux NFSv4 client.
The Linux folks have changed their patch to avoid this, but this
patch fixes the problem on the server.
Reported and tested by: Andre Heider (a.heider@gmail.com)
MFC after: 3 days
credentials to the kernel rpc. Modify the NFSv4 client to add
support for the gssname and allgssname mount options to use this
capability. Requires the gssd daemon to be running with the "-h" option.
Reviewed by: jhb
it will work with either the old or new server.
The FHA code keeps a cache of currently active file handles for
NFSv2 and v3 requests, so that read and write requests for the same
file are directed to the same group of threads (reads) or thread
(writes). It does not currently work for NFSv4 requests. They are
more complex, and will take more work to support.
This improves read-ahead performance, especially with ZFS, if the
FHA tuning parameters are configured appropriately. Without the
FHA code, concurrent reads that are part of a sequential read from
a file will be directed to separate NFS threads. This has the
effect of confusing the ZFS zfetch (prefetch) code and makes
sequential reads significantly slower with clients like Linux that
do a lot of prefetching.
The FHA code has also been updated to direct write requests to nearby
file offsets to the same thread in the same way it batches reads,
and the FHA code will now also send writes to multiple threads when
needed.
This improves sequential write performance in ZFS, because writes
to a file are now more ordered. Since NFS writes (generally
less than 64K) are smaller than the typical ZFS record size
(usually 128K), out of order NFS writes to the same block can
trigger a read in ZFS. Sending them down the same thread increases
the odds of their being in order.
In order for multiple write threads per file in the FHA code to be
useful, writes in the NFS server have been changed to use a LK_SHARED
vnode lock, and upgrade that to LK_EXCLUSIVE if the filesystem
doesn't allow multiple writers to a file at once. ZFS is currently
the only filesystem that allows multiple writers to a file, because
it has internal file range locking. This change does not affect the
NFSv4 code.
This improves random write performance to a single file in ZFS, since
we can now have multiple writers inside ZFS at one time.
I have changed the default tuning parameters to a 22 bit (4MB)
window size (from 256K) and unlimited commands per thread as a
result of my benchmarking with ZFS.
The FHA code has been updated to allow configuring the tuning
parameters from loader tunable variables in addition to sysctl
variables. The read offset window calculation has been slightly
modified as well. Instead of having separate bins, each file
handle has a rolling window of bin_shift size. This minimizes
glitches in throughput when shifting from one bin to another.
sys/conf/files:
Add nfs_fha_new.c and nfs_fha_old.c. Compile nfs_fha.c
when either the old or the new NFS server is built.
sys/fs/nfs/nfsport.h,
sys/fs/nfs/nfs_commonport.c:
Bring in changes from Rick Macklem to newnfs_realign that
allow it to operate in blocking (M_WAITOK) or non-blocking
(M_NOWAIT) mode.
sys/fs/nfs/nfs_commonsubs.c,
sys/fs/nfs/nfs_var.h:
Bring in a change from Rick Macklem to allow telling
nfsm_dissect() whether or not to wait for mallocs.
sys/fs/nfs/nfsm_subs.h:
Bring in changes from Rick Macklem to create a new
nfsm_dissect_nonblock() inline function and
NFSM_DISSECT_NONBLOCK() macro.
sys/fs/nfs/nfs_commonkrpc.c,
sys/fs/nfsclient/nfs_clkrpc.c:
Add the malloc wait flag to a newnfs_realign() call.
sys/fs/nfsserver/nfs_nfsdkrpc.c:
Setup the new NFS server's RPC thread pool so that it will
call the FHA code.
Add the malloc flag argument to newnfs_realign().
Unstaticize newnfs_nfsv3_procid[] so that we can use it in
the FHA code.
sys/fs/nfsserver/nfs_nfsdsocket.c:
In nfsrvd_dorpc(), add NFSPROC_WRITE to the list of RPC types
that use the LK_SHARED lock type.
sys/fs/nfsserver/nfs_nfsdport.c:
In nfsd_fhtovp(), if we're starting a write, check to see
whether the underlying filesystem supports shared writes.
If not, upgrade the lock type from LK_SHARED to LK_EXCLUSIVE.
sys/nfsserver/nfs_fha.c:
Remove all code that is specific to the NFS server
implementation. Anything that is server-specific is now
accessed through a callback supplied by that server's FHA
shim in the new softc.
There are now separate sysctls and tunables for the FHA
implementations for the old and new NFS servers. The new
NFS server has its tunables under vfs.nfsd.fha, the old
NFS server's tunables are under vfs.nfsrv.fha as before.
In fha_extract_info(), use callouts for all server-specific
code. Getting file handles and offsets is now done in the
individual server's shim module.
In fha_hash_entry_choose_thread(), change the way we decide
whether two reads are in proximity to each other.
Previously, the calculation was a simple shift operation to
see whether the offsets were in the same power of 2 bucket.
The issue was that there would be a bucket (and therefore
thread) transition, even if the reads were in close
proximity. When there is a thread transition, reads wind
up going somewhat out of order, and ZFS gets confused.
The new calculation simply tries to see whether the offsets
are within 1 << bin_shift of each other. If they are, the
reads will be sent to the same thread.
The effect of this change is that for sequential reads, if
the client doesn't exceed the max_reqs_per_nfsd parameter
and the bin_shift is set to a reasonable value (22, or
4MB works well in my tests), the reads in any sequential
stream will largely be confined to a single thread.
Change fha_assign() so that it takes a softc argument. It
is now called from the individual server's shim code, which
will pass in the softc.
Change fhe_stats_sysctl() so that it takes a softc
parameter. It is now called from the individual server's
shim code. Add the current offset to the list of things
printed out about each active thread.
Change the num_reads and num_writes counters in the
fha_hash_entry structure to 32-bit values, and rename them
num_rw and num_exclusive, respectively, to reflect their
changed usage.
Add an enable sysctl and tunable that allows the user to
disable the FHA code (when vfs.XXX.fha.enable = 0). This
is useful for before/after performance comparisons.
nfs_fha.h:
Move most structure definitions out of nfs_fha.c and into
the header file, so that the individual server shims can
see them.
Change the default bin_shift to 22 (4MB) instead of 18
(256K). Allow unlimited commands per thread.
sys/nfsserver/nfs_fha_old.c,
sys/nfsserver/nfs_fha_old.h,
sys/fs/nfsserver/nfs_fha_new.c,
sys/fs/nfsserver/nfs_fha_new.h:
Add shims for the old and new NFS servers to interface with
the FHA code, and callbacks for the
The shims contain all of the code and definitions that are
specific to the NFS servers.
They setup the server-specific callbacks and set the server
name for the sysctl and loader tunable variables.
sys/nfsserver/nfs_srvkrpc.c:
Configure the RPC code to call fhaold_assign() instead of
fha_assign().
sys/modules/nfsd/Makefile:
Add nfs_fha.c and nfs_fha_new.c.
sys/modules/nfsserver/Makefile:
Add nfs_fha_old.c.
Reviewed by: rmacklem
Sponsored by: Spectra Logic
MFC after: 2 weeks
- Capability is no longer separate descriptor type. Now every descriptor
has set of its own capability rights.
- The cap_new(2) system call is left, but it is no longer documented and
should not be used in new code.
- The new syscall cap_rights_limit(2) should be used instead of
cap_new(2), which limits capability rights of the given descriptor
without creating a new one.
- The cap_getrights(2) syscall is renamed to cap_rights_get(2).
- If CAP_IOCTL capability right is present we can further reduce allowed
ioctls list with the new cap_ioctls_limit(2) syscall. List of allowed
ioctls can be retrived with cap_ioctls_get(2) syscall.
- If CAP_FCNTL capability right is present we can further reduce fcntls
that can be used with the new cap_fcntls_limit(2) syscall and retrive
them with cap_fcntls_get(2).
- To support ioctl and fcntl white-listing the filedesc structure was
heavly modified.
- The audit subsystem, kdump and procstat tools were updated to
recognize new syscalls.
- Capability rights were revised and eventhough I tried hard to provide
backward API and ABI compatibility there are some incompatible changes
that are described in detail below:
CAP_CREATE old behaviour:
- Allow for openat(2)+O_CREAT.
- Allow for linkat(2).
- Allow for symlinkat(2).
CAP_CREATE new behaviour:
- Allow for openat(2)+O_CREAT.
Added CAP_LINKAT:
- Allow for linkat(2). ABI: Reuses CAP_RMDIR bit.
- Allow to be target for renameat(2).
Added CAP_SYMLINKAT:
- Allow for symlinkat(2).
Removed CAP_DELETE. Old behaviour:
- Allow for unlinkat(2) when removing non-directory object.
- Allow to be source for renameat(2).
Removed CAP_RMDIR. Old behaviour:
- Allow for unlinkat(2) when removing directory.
Added CAP_RENAMEAT:
- Required for source directory for the renameat(2) syscall.
Added CAP_UNLINKAT (effectively it replaces CAP_DELETE and CAP_RMDIR):
- Allow for unlinkat(2) on any object.
- Required if target of renameat(2) exists and will be removed by this
call.
Removed CAP_MAPEXEC.
CAP_MMAP old behaviour:
- Allow for mmap(2) with any combination of PROT_NONE, PROT_READ and
PROT_WRITE.
CAP_MMAP new behaviour:
- Allow for mmap(2)+PROT_NONE.
Added CAP_MMAP_R:
- Allow for mmap(PROT_READ).
Added CAP_MMAP_W:
- Allow for mmap(PROT_WRITE).
Added CAP_MMAP_X:
- Allow for mmap(PROT_EXEC).
Added CAP_MMAP_RW:
- Allow for mmap(PROT_READ | PROT_WRITE).
Added CAP_MMAP_RX:
- Allow for mmap(PROT_READ | PROT_EXEC).
Added CAP_MMAP_WX:
- Allow for mmap(PROT_WRITE | PROT_EXEC).
Added CAP_MMAP_RWX:
- Allow for mmap(PROT_READ | PROT_WRITE | PROT_EXEC).
Renamed CAP_MKDIR to CAP_MKDIRAT.
Renamed CAP_MKFIFO to CAP_MKFIFOAT.
Renamed CAP_MKNODE to CAP_MKNODEAT.
CAP_READ old behaviour:
- Allow pread(2).
- Disallow read(2), readv(2) (if there is no CAP_SEEK).
CAP_READ new behaviour:
- Allow read(2), readv(2).
- Disallow pread(2) (CAP_SEEK was also required).
CAP_WRITE old behaviour:
- Allow pwrite(2).
- Disallow write(2), writev(2) (if there is no CAP_SEEK).
CAP_WRITE new behaviour:
- Allow write(2), writev(2).
- Disallow pwrite(2) (CAP_SEEK was also required).
Added convinient defines:
#define CAP_PREAD (CAP_SEEK | CAP_READ)
#define CAP_PWRITE (CAP_SEEK | CAP_WRITE)
#define CAP_MMAP_R (CAP_MMAP | CAP_SEEK | CAP_READ)
#define CAP_MMAP_W (CAP_MMAP | CAP_SEEK | CAP_WRITE)
#define CAP_MMAP_X (CAP_MMAP | CAP_SEEK | 0x0000000000000008ULL)
#define CAP_MMAP_RW (CAP_MMAP_R | CAP_MMAP_W)
#define CAP_MMAP_RX (CAP_MMAP_R | CAP_MMAP_X)
#define CAP_MMAP_WX (CAP_MMAP_W | CAP_MMAP_X)
#define CAP_MMAP_RWX (CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X)
#define CAP_RECV CAP_READ
#define CAP_SEND CAP_WRITE
#define CAP_SOCK_CLIENT \
(CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \
CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN)
#define CAP_SOCK_SERVER \
(CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \
CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \
CAP_SETSOCKOPT | CAP_SHUTDOWN)
Added defines for backward API compatibility:
#define CAP_MAPEXEC CAP_MMAP_X
#define CAP_DELETE CAP_UNLINKAT
#define CAP_MKDIR CAP_MKDIRAT
#define CAP_RMDIR CAP_UNLINKAT
#define CAP_MKFIFO CAP_MKFIFOAT
#define CAP_MKNOD CAP_MKNODAT
#define CAP_SOCK_ALL (CAP_SOCK_CLIENT | CAP_SOCK_SERVER)
Sponsored by: The FreeBSD Foundation
Reviewed by: Christoph Mallon <christoph.mallon@gmx.de>
Many aspects discussed with: rwatson, benl, jonathan
ABI compatibility discussed with: kib
changes in r246417 were incomplete as they did not add explicit calls to
sigdeferstop() around all the places that previously passed SBDRY to
_sleep(). In addition, nfs_getcacheblk() could trigger a write RPC from
getblk() resulting in sigdeferstop() recursing. Rather than manually
deferring stop signals in specific places, change the VFS_*() and VOP_*()
methods to defer stop signals for filesystems which request this behavior
via a new VFCF_SBDRY flag. Note that this has to be a VFC flag rather than
a MNTK flag so that it works properly with VFS_MOUNT() when the mount is
not yet fully constructed. For now, only the NFS clients are set this new
flag in VFS_SET().
A few other related changes:
- Add an assertion to ensure that TDF_SBDRY doesn't leak to userland.
- When a lookup request uses VOP_READLINK() to follow a symlink, mark
the request as being on behalf of the thread performing the lookup
(cnp_thread) rather than using a NULL thread pointer. This causes
NFS to properly handle signals during this VOP on an interruptible
mount.
PR: kern/176179
Reported by: Russell Cattelan (sigdeferstop() recursion)
Reviewed by: kib
MFC after: 1 month
195702, 195703, and 195821 prevented a thread from suspending while holding
locks inside of NFS by forcing the thread to fail sleeps with EINTR or
ERESTART but defer the thread suspension to the user boundary. However,
this had the effect that stopping a process during an NFS request could
abort the request and trigger EINTR errors that were visible to userland
processes (previously the thread would have suspended and completed the
request once it was resumed).
This change instead effectively masks stop signals while in the NFS client.
It uses the existing TDF_SBDRY flag to effect this since SIGSTOP cannot
be masked directly. Also, instead of setting PBDRY on individual sleeps,
the NFS client now sets the TDF_SBDRY flag around each NFS request and
stop signals are masked for all sleeps during that region (the previous
change missed sleeps in lockmgr locks). The end result is that stop
signals sent to threads performing an NFS request are completely
ignored until after the NFS request has finished processing and the
thread prepares to return to userland. This restores the behavior of
stop signals being transparent to userland processes while still
preventing threads from suspending while holding NFS locks.
Reviewed by: kib
MFC after: 1 month
this check is somewhere in the network code, but this assertion
already proven to be useful in catching what seems to be driver bugs
causing NFS scrambling random memory.
Discussed with: rmacklem
MFC after: 1 week
- Use NFSD_MONOSEC (which maps to time_uptime) instead of the seconds
portion of wall-time stamps to manage timeouts on events.
- Remove unused nd_starttime from the per-request structure in the new
NFS server.
- Use nanotime() for the modification time on a delegation to get as
precise a time as possible.
- Use time_second instead of extracting the second from a call to
getmicrotime().
Submitted by: bde (3)
Reviewed by: bde, rmacklem
MFC after: 2 weeks
by returning an error of EINTR rather than EACCES.
- While here, bring back some (but not all) of the NFS RPC statistics lost
when krpc was committed.
Reviewed by: rmacklem
MFC after: 1 week
