file via NFS. Specifically, to satisfy close-to-open-consistency, the NFS
client always performs at least one RPC on a file during an open(2) to see
if the file has changed. Normally this RPC is an ACCESS or GETATTR RPC
that is forced by flushing a file's attribute cache during nfs_open() and
then requesting new attributes. However, if the file is noticed to be
stale during nfs_open(), the only recourse is to fail the open(2) call
with ESTALE. On the other hand, if the ACCESS or GETATTR RPC is sent
during nfs_lookup(), then the NFS client can fall back to a LOOKUP RPC to
obtain the new file handle in the case that a file has been replaced.
This change causes the NFS client to flush the attribute cache during
nfs_lookup() when validating a name cache hit if the attributes fetched
during nfs_lookup() can be reused in nfs_open(). This allows the client
to open a replaced file via the new file handle the first time that it
notices a replaced file rather than failing with ESTALE in some cases.
Reviewed by: rmacklem, bde
Reviewed by: mohans (older version)
MFC after: 1 week
the jail(8) command. [10:04]
Fix a one-NUL-byte buffer overflow in libopie. [10:05]
Correctly sanity-check a buffer length in nfs mount. [10:06]
Approved by: so (cperciva)
Approved by: re (kensmith)
Security: FreeBSD-SA-10:04.jail
Security: FreeBSD-SA-10:05.opie
Security: FreeBSD-SA-10:06.nfsclient
managed pages that didn't already have that lock held. (Freeing an
unmanaged page, such as the various pmaps use, doesn't require the page
lock.)
This allows a change in vm_page_remove()'s locking requirements. It now
expects the page lock to be held instead of the page queues lock.
Consequently, the page queues lock is no longer required at all by callers
to vm_page_rename().
Discussed with: kib
module. With r203732 it became apparent that creating the sysctl nodes
twice causes at least a warning, however the whole code shouldn't be
present twice in the first place.
Discussed with: rmacklem
remove the NFS server version in order to reduce code duplication.
The shared version now uses a second parameter how, which is passed
on to m_get(9) and m_getcl(9) as the server used M_WAIT while the
client requires M_DONTWAIT, and replaces the the previously unused
parameter hsiz.
- Change nfs_realign() to use nfsm_aligned() so as with other NFS code
the alignment check isn't actually performed on platforms without
strict alignment requirements for performance reasons because as the
comment suggests unaligned data only occasionally occurs with TCP.
- Change fha_extract_info() to use nfs_realign() with M_DONTWAIT rather
than M_WAIT because it's called with the RPC sp_lock held.
Reviewed by: jhb, rmacklem
MFC after: 1 week
Without this patch it was possible for a different thread that calls
nfs_asyncio() to snitch a newly created nfsiod thread that was
intended for another caller of nfs_asyncio(), because the nfs_iod_mtx
mutex was unlocked while the new nfsiod thread was created. This patch
labels the newly created nfsiod, so that it is not taken by another
caller of nfs_asyncio(). This is believed to fix the problem reported
on the freebsd-stable email list under the subject:
FreeBSD NFS client/Linux NFS server issue.
Tested by: to DOT my DOT trociny AT gmail DOT com
Reviewed by: jhb
MFC after: 2 weeks
This avoids a bogus negative name cache entry from persisting forever
when another client creates an entry with the same name within the
same NFS server time of day clock tick. The mount option negnametimeo
can be used to override the default timeout interval on a
per-mount-point basis. Setting negnametimeo to 0 disables negative
name caching for the mount point.
I also fixed one obvious typo where args.timeo should be
args.maxgrouplist.
Submitted by: jhb (earlier version)
Reviewed by: jhb
MFC after: 2 weeks
kernel to boot from NFS. [1]
Note: this is not a full virtualization of nfsclient. It is only does
what advertised above and nothing more.
Requested by: public demand [1]
Tested by: kris, ..
MFC after: 5 days
Specifically, clients only trust -ve cache entries while the directory
remains unchanged and discard any -ve cache entries for a directory when
they notice that the modification time of a directory entry changes. The
race involves two concurrent lookups as follows:
- Thread A does a lookup for file 'foo' which sends a lookup RPC to the
server. The lookup fails and the server replies.
- The 'foo' file is created (either by the same client or a different
client) updating the modification time on the parent directory of 'foo'.
- Thread B does a lookup for a different file 'bar' which updates the
cached attributes of the parent directory of 'foo' to reflect the new
modification time after 'foo' was created.
- Thread A finally resumes execution to parse the reply from the NFS
server. It adds a -ve cache entry and sets the cached value of the
directory's modification time that is used for invalidating -ve cached
lookups to the new modification time set by thread B.
At this point, future lookups of 'foo' will honor the -ve cached entry
until the cached entry is pushed out of the name cache's LRU or the
modification time of the parent directory is changed again by some other
change. The fix is to read the directory's modification time before
sending the lookup RPC and use that cached modification time when setting
the directory's cached modification time. Also, we do not add a -ve cache
entry if another thread has added -ve cache entry that set the directory's
cached modification time to a newer value than the value we read before
sending the lookup RPC.
Reviewed by: rmacklem
MFC after: 1 week
fixes their issues but one reports a failure in NFS ROOT. Revert
the change for now pending further investigation.
Reviewed by: bz
MFC after: immediately
module tries to install the same address again. This extra code
is removed, which was discovered by the removal of a call to
in_ifscrub() in r196714. This call to in_ifscrub is put back here
because the SIOCAIFADDR command can be used to change the prefix
length of an existing alias.
Reviewed by: kmacy
vnodes, since these nodes are not linked into the mount queue and,
as such, the vn_lock() cannot cause a deadlock so LORs are harmless.
Suggested by: kib
Approved by: kib (mentor)
MFC after: 3 days
context inside the RPC code.
Temporarily set td's cred to mount's cred before calling socreate() via
__rpc_nconf2socket().
Submitted by: rmacklem (in part)
Reviewed by: rmacklem, rwatson
Discussed with: dfr, bz
Approved by: re (rwatson), julian (mentor)
MFC after: 3 days
several critical bugs, including race conditions and lock order issues:
Replace the single rwlock, ifnet_lock, with two locks, an rwlock and an
sxlock. Either can be held to stablize the lists and indexes, but both
are required to write. This allows the list to be held stable in both
network interrupt contexts and sleepable user threads across sleeping
memory allocations or device driver interactions. As before, writes to
the interface list must occur from sleepable contexts.
Reviewed by: bz, julian
MFC after: 3 days
pathes, as far as I see and testing seems to confirm it. Comparision of
old_lock with LK_SHARED make sense only if vnode is locked by current
thread.
When downgrading, pass LK_RETRY to the vn_lock(), since otherwise
vn_lock() unlocks the doomed vnode, causing extra unlock.
Reported and tested by: pho
Approved by: re (rwatson)
MFC after: 3 weeks
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks. Minor cleanups are done in the process,
and comments updated to reflect these changes.
Reviewed by: bz
Approved by: re (vimage blanket)
r195704 for the experimental client. The patch avoids calling vn_lock()
for the case where nfs_nget() has acquired the same vnode as dvp,
since nfs_nget() has already locked the vnode.
Reviewed by: kib, jhb
Approved by: re (kensmith), kib (mentor)
kernel resources that block other threads, like vnode locks. The SIGSTOP
sent to such thread (process, rather) shall not stop it until thread
releases the resources.
Tested by: pho
Reviewed by: jhb
Approved by: re (kensmith)
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator. Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...). This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.
Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack. Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory. Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.
Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy. Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address. When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.
This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.
Bump __FreeBSD_version and update UPDATING.
Portions submitted by: bz
Reviewed by: bz, zec
Discussed with: gnn, jamie, jeff, jhb, julian, sam
Suggested by: peter
Approved by: re (kensmith)
around the sequence that drop vnode lock and then busies the mount point.
Not having vlocked node or direct reference to the mp allows for the
forced unmount to proceed, making mp unmounted or reused.
Tested by: pho
Reviewed by: jeff
Approved by: re (kensmith)
MFC after: 2 weeks
in_ifaddrhead and INADDR_HASH address lists.
Previously, these lists were used unsynchronized as they were effectively
never changed in steady state, but we've seen increasing reports of
writer-writer races on very busy VPN servers as core count has gone up
(and similar configurations where address lists change frequently and
concurrently).
For the time being, use rwlocks rather than rmlocks in order to take
advantage of their better lock debugging support. As a result, we don't
enable ip_input()'s read-locking of INADDR_HASH until an rmlock conversion
is complete and a performance analysis has been done. This means that one
class of reader-writer races still exists.
MFC after: 6 weeks
Reviewed by: bz
operating on the unmounted mount point and freed mount data in case of
forced unmount performed while dvp is unlocked to nget the target vnode.
Add missed calls to m_freem(mrep) there on error exits [1].
Submitted by: rmacklem [1]
Tested by: pho
MFC after: 2 weeks
nfs_bioread_check_cons(). This is required since it is possible
for the vnode to be vgonel()'d while in nfs_upgrade_vnlock() when
a forced dismount is in progress. Also, move the check for VI_DOOMED
in nfs_vinvalbuf() down to after nfs_upgrade_vnlock() and replace the
out of date comment for it.
Submitted by: jhb
Tested by: pho
Approved by: kib (mentor)
MFC after: 1 month
the ROUTETABLES kernel option thus there is no need to include opt_route.h
anymore in all consumers of vnet.h and no longer depend on it for module
builds.
Remove the hidden include in flowtable.h as well and leave the two
explicit #includes in ip_input.c and ip_output.c.
- Each socket upcall is now invoked with the appropriate socket buffer
locked. It is not permissible to call soisconnected() with this lock
held; however, so socket upcalls now return an integer value. The two
possible values are SU_OK and SU_ISCONNECTED. If an upcall returns
SU_ISCONNECTED, then the soisconnected() will be invoked on the
socket after the socket buffer lock is dropped.
- A new API is provided for setting and clearing socket upcalls. The
API consists of soupcall_set() and soupcall_clear().
- To simplify locking, each socket buffer now has a separate upcall.
- When a socket upcall returns SU_ISCONNECTED, the upcall is cleared from
the receive socket buffer automatically. Note that a SO_SND upcall
should never return SU_ISCONNECTED.
- All this means that accept filters should now return SU_ISCONNECTED
instead of calling soisconnected() directly. They also no longer need
to explicitly clear the upcall on the new socket.
- The HTTP accept filter still uses soupcall_set() to manage its internal
state machine, but other accept filters no longer have any explicit
knowlege of socket upcall internals aside from their return value.
- The various RPC client upcalls currently drop the socket buffer lock
while invoking soreceive() as a temporary band-aid. The plan for
the future is to add a new flag to allow soreceive() to be called with
the socket buffer locked.
- The AIO callback for socket I/O is now also invoked with the socket
buffer locked. Previously sowakeup() would drop the socket buffer
lock only to call aio_swake() which immediately re-acquired the socket
buffer lock for the duration of the function call.
Discussed with: rwatson, rmacklem
an accessor function to get the correct rnh pointer back.
Update netstat to get the correct pointer using kvm_read()
as well.
This not only fixes the ABI problem depending on the kernel
option but also permits the tunable to overwrite the kernel
option at boot time up to MAXFIBS, enlarging the number of
FIBs without having to recompile. So people could just use
GENERIC now.
Reviewed by: julian, rwatson, zec
X-MFC: not possible
The system hostname is now stored in prison0, and the global variable
"hostname" has been removed, as has the hostname_mtx mutex. Jails may
have their own host information, or they may inherit it from the
parent/system. The proper way to read the hostname is via
getcredhostname(), which will copy either the hostname associated with
the passed cred, or the system hostname if you pass NULL. The system
hostname can still be accessed directly (and without locking) at
prison0.pr_host, but that should be avoided where possible.
The "similar information" referred to is domainname, hostid, and
hostuuid, which have also become prison parameters and had their
associated global variables removed.
Approved by: bz (mentor)
on platforms with strict alignment requirements. In particular, this fixes the
problems with the new RPC transport on the arm platform.
Note: this adds yet another copy of nfs_realign(). I will attempt to refactor
after NFS_LEGACYRPC is removed.
Submitted by: sam
the VFS. Now all the VFS_* functions and relating parts don't want the
context as long as it always refers to curthread.
In some points, in particular when dealing with VOPs and functions living
in the same namespace (eg. vflush) which still need to be converted,
pass curthread explicitly in order to retain the old behaviour.
Such loose ends will be fixed ASAP.
While here fix a bug: now, UFS_EXTATTR can be compiled alone without the
UFS_EXTATTR_AUTOSTART option.
VFS KPI is heavilly changed by this commit so thirdy parts modules needs
to be recompiled. Bump __FreeBSD_version in order to signal such
situation.
previously always pointing to the default vnet context, to a
dynamically changing thread-local one. The currvnet context
should be set on entry to networking code via CURVNET_SET() macros,
and reverted to previous state via CURVNET_RESTORE(). Recursions
on curvnet are permitted, though strongly discuouraged.
This change should have no functional impact on nooptions VIMAGE
kernel builds, where CURVNET_* macros expand to whitespace.
The curthread->td_vnet (aka curvnet) variable's purpose is to be an
indicator of the vnet context in which the current network-related
operation takes place, in case we cannot deduce the current vnet
context from any other source, such as by looking at mbuf's
m->m_pkthdr.rcvif->if_vnet, sockets's so->so_vnet etc. Moreover, so
far curvnet has turned out to be an invaluable consistency checking
aid: it helps to catch cases when sockets, ifnets or any other
vnet-aware structures may have leaked from one vnet to another.
The exact placement of the CURVNET_SET() / CURVNET_RESTORE() macros
was a result of an empirical iterative process, whith an aim to
reduce recursions on CURVNET_SET() to a minimum, while still reducing
the scope of CURVNET_SET() to networking only operations - the
alternative would be calling CURVNET_SET() on each system call entry.
In general, curvnet has to be set in three typicall cases: when
processing socket-related requests from userspace or from within the
kernel; when processing inbound traffic flowing from device drivers
to upper layers of the networking stack, and when executing
timer-driven networking functions.
This change also introduces a DDB subcommand to show the list of all
vnet instances.
Approved by: julian (mentor)
the removal of NQNFS, but was left in in case it was required for NFSv4.
Since our new NFSv4 client and server can't use it for their
requirements, GC the old mechanism, as well as other unused lease-
related code and interfaces.
Due to its impact on kernel programming and binary interfaces, this
change should not be MFC'd.
Proposed by: jeff
Reviewed by: jeff
Discussed with: rmacklem, zach loafman @ isilon
Check the condition and return ENOENT then.
In nfs_lookup(), respect ENOENT return from cache_lookup() when it is caused
by dvp reclaim.
Reported and tested by: pho
an NFS node including the access and attribute caches. Previously the NFS
client only purged any name cache entries associated with the file.
PR: kern/123755
Submitted by: Jaakko Heinonen jh of saunalahti fi
Reported by: Timo Sirainen tss of iki fi
Reviewed by: rwatson, rmacklem
MFC after: 1 month
client from 30 seconds to 3 seconds. After the recent changes to add
caching of negative name cache lookups, a negative name cache hit will
persist until the client notices the parent directory has changed. The
higher the attribute cache timeout on directories, the longer that can take,
so lower the default timeout for directories to match that of regular files.
Suggested by: bde, mohans
MFC after: 1 month
- Trace non-error loads into the access cache once, not zero times or
twice.
- Sometimes attr cache loads fail due to a race, in which case they are
aborted leading to an invalidation; in this case, trace only the flush,
not a load.
MFC after: 1 month
Sponsored by: Google, Inc.
events are:
nfsclient:accesscache:flush:done
nfsclient:accesscache:get:hit
nfsclient:accesscache:get:miss
nfsclient:accesscache:load:done
They pass the vnode, uid, and requested or loaded access mode (if any);
the load event may also report a load error if the RPC fails.
The attribute cache events are:
nfsclient:attrcache:flush:done
nfsclient:attrcache:get:hit
nfsclient:attrcache:get:miss
nfsclient:attrcache:load:done
They pass the vnode, optionally the vattr if one is present (hit or load),
and in the case of a load event, also a possible RPC error.
MFC after: 1 month
Sponsored by: Google, Inc.
provider. The NFS client exposes 'start' and 'done' probes for NFSv2
and NFSv3 RPCs when using the new RPC implementation, passing in the
vnode, mbuf chain, credential, and NFSv2 or NFSv3 procedure number.
For 'done' probes, the error number is also available.
Probes are named in the following way:
...
nfsclient:nfs2:write:start
nfsclient:nfs2:write:done
...
nfsclient:nfs3:access:start
nfsclient:nfs3:access:done
...
Access to the unmarshalled arguments is not easily available at this
point in the stack, but the passed probe arguments are sufficient to
to a lot of interesting things in practice. Technically, these probes
may cover multiple RPC retransmits, and even transactions if the
transaction ID change as a result of authentication failure or a
jukebox error from the server, but usefully capture the intent of a
single NFS request, such as access, getattr, write, etc.
Typical use might involve profiling RPC latency by system call, number
of RPCs, how often a getattr leads to a call to access, when failed
access control checks occur, etc. More detailed RPC information might
best be provided by adding a krpc provider. It would also be useful
to add NFS client probes for events such as the access cache or
attribute cache satisfying requests without an RPC.
Sponsored by: Google, Inc.
MFC after: 1 month
definitely doing an NFSv2 or NFSv3 RPC, rather than sometimes doing
so and sometimes not. This makes it easier to add a DTrace return
probe at a single point in the function.
MFC after: 1 week
The number of entries in the cache defaults to 8 but is easily changed in
nfsclient/nfs.h. When the cache is filled, the oldest cache entry is
evicted when space is needed.
I mirrored the changes to the NFSv[23] client in the NFSv4 client to fix
compile breakage. However, the NFSv4 client doesn't actually use the
access cache currently.
Submitted by: rmacklem
hit in the name cache. cache_lookup() doesn't actually return ENOENT
for such requests to force the filesystem to do an explicit lookup, so
this was effectively dead code.
- Grab the nfsnode mutex while writing to n_dmtime. We don't grab the lock
when comparing the time against the cached directory mod time (just as
we don't when comparing ctime's for +ve name cache hits) since the
attribute caching is already racy for NFS clients as it is.
Discussed with: bde
net/route.h.
Remove the hidden include of opt_route.h and net/route.h from net/vnet.h.
We need to make sure that both opt_route.h and net/route.h are included
before net/vnet.h because of the way MRT figures out the number of FIBs
from the kernel option. If we do not, we end up with the default number
of 1 when including net/vnet.h and array sizes are wrong.
This does not change the list of files which depend on opt_route.h
but we can identify them now more easily.
an NFS file. Now the priming is conditional on a new
vfs.nfs.prime_access_cache sysctl. For now I've left the default setting
to disabling the priming.
Requested by: scottl
stale entries, we save a copy of the directory's modification time when
the first negative cache entry was added in the directory's NFS node.
When a negative cache entry is hit during a pathname lookup, the parent
directory's modification time is checked. If it has changed, all of the
negative cache entries for that parent are purged and the lookup falls
back to using the RPC. This required adding a new cache_purge_negative()
method to the name cache to purge only negative cache entries for a given
directory.
Submitted by: mohans, Rick Macklem, Ricardo Labiaga @ NetApp
Reviewed by: mohans
opportunistic ACCESS RPC to populate both the access and attribute caches
of the file and instead always use a GETATTR RPC. On many modern NFS
servers, an ACCESS RPC is much more expensive to service than a GETATTR
RPC.
Submitted by: mohans
open() of the same file will load fresh attributes, so they do not need to
be explicitly flushed in close() to guarantee close to open consistency.
However, other file desciptors may still reference this file and clearing
the attributes in close() forces those other file descriptors to fetch
fresh attributes the next time they need them.
Reviewed by: mohans
MFC after: 1 week
Inside the kernel, the minor() function was responsible for obtaining
the device minor number of a character device. Because we made device
numbers dynamically allocated and independent of the unit number passed
to make_dev() a long time ago, it was actually a misnomer. If you really
want to obtain the device number, you should use dev2udev().
We already converted all the drivers to use dev2unit() to obtain the
device unit number, which is still used by a lot of drivers. I've
noticed not a single driver passes NULL to dev2unit(). Even if they
would, its behaviour would make little sense. This is why I've removed
the NULL check.
Ths commit removes minor(), minor2unit() and unit2minor() from the
kernel. Because there was a naming collision with uminor(), we can
rename umajor() and uminor() back to major() and minor(). This means
that the makedev(3) manual page also applies to kernel space code now.
I suspect umajor() and uminor() isn't used that often in external code,
but to make it easier for other parties to port their code, I've
increased __FreeBSD_version to 800062.
VOP_MARKATIME() since unlike the rest of VOP_SETATTR(), VA_MARKATIME
can be performed while holding a shared vnode lock (the same functionality
is done internally by VOP_READ which can run with a shared vnode lock).
Add missing locking of the vnode interlock to the ufs implementation and
remove a special note and test from the NFS client about not supporting the
feature.
Inspired by: ups
Tested by: pho
directly include only the header files needed. This reduces the
unneeded spamming of various headers into lots of files.
For now, this leaves us with very few modules including vnet.h
and thus needing to depend on opt_route.h.
Reviewed by: brooks, gnn, des, zec, imp
Sponsored by: The FreeBSD Foundation
I have fixed the reported problems - if you still have trouble with it, please
contact me with as much detail as possible so that I can track down any other
issues as quickly as possible.
fix the problems a few people have noticed with the new code. People who want
to continue testing the new code or who need RPCSEC_GSS support should use
the new option NFS_NEWRPC to select it.
and server. This replaces the RPC implementation of the NFS client and
server with the newer RPC implementation originally developed
(actually ported from the userland sunrpc code) to support the NFS
Lock Manager. I have tested this code extensively and I believe it is
stable and that performance is at least equal to the legacy RPC
implementation.
The NFS code currently contains support for both the new RPC
implementation and the older legacy implementation inherited from the
original NFS codebase. The default is to use the new implementation -
add the NFS_LEGACYRPC option to fall back to the old code. When I
merge this support back to RELENG_7, I will probably change this so
that users have to 'opt in' to get the new code.
To use RPCSEC_GSS on either client or server, you must build a kernel
which includes the KGSSAPI option and the crypto device. On the
userland side, you must build at least a new libc, mountd, mount_nfs
and gssd. You must install new versions of /etc/rc.d/gssd and
/etc/rc.d/nfsd and add 'gssd_enable=YES' to /etc/rc.conf.
As long as gssd is running, you should be able to mount an NFS
filesystem from a server that requires RPCSEC_GSS authentication. The
mount itself can happen without any kerberos credentials but all
access to the filesystem will be denied unless the accessing user has
a valid ticket file in the standard place (/tmp/krb5cc_<uid>). There
is currently no support for situations where the ticket file is in a
different place, such as when the user logged in via SSH and has
delegated credentials from that login. This restriction is also
present in Solaris and Linux. In theory, we could improve this in
future, possibly using Brooks Davis' implementation of variant
symlinks.
Supporting RPCSEC_GSS on a server is nearly as simple. You must create
service creds for the server in the form 'nfs/<fqdn>@<REALM>' and
install them in /etc/krb5.keytab. The standard heimdal utility ktutil
makes this fairly easy. After the service creds have been created, you
can add a '-sec=krb5' option to /etc/exports and restart both mountd
and nfsd.
The only other difference an administrator should notice is that nfsd
doesn't fork to create service threads any more. In normal operation,
there will be two nfsd processes, one in userland waiting for TCP
connections and one in the kernel handling requests. The latter
process will create as many kthreads as required - these should be
visible via 'top -H'. The code has some support for varying the number
of service threads according to load but initially at least, nfsd uses
a fixed number of threads according to the value supplied to its '-n'
option.
Sponsored by: Isilon Systems
MFC after: 1 month
- Implement real draining for vfs consumers by not relying on the
mnt_lock and using instead a refcount in order to keep track of lock
requesters.
- Due to the change above, remove the mnt_lock lockmgr because it is now
useless.
- Due to the change above, vfs_busy() is no more linked to a lockmgr.
Change so its KPI by removing the interlock argument and defining 2 new
flags for it: MBF_NOWAIT which basically replaces the LK_NOWAIT of the
old version (which was unlinked from the lockmgr alredy) and
MBF_MNTLSTLOCK which provides the ability to drop the mountlist_mtx
once the mnt interlock is held (ability still desired by most consumers).
- The stub used into vfs_mount_destroy(), that allows to override the
mnt_ref if running for more than 3 seconds, make it totally useless.
Remove it as it was thought to work into older versions.
If a problem of "refcount held never going away" should appear, we will
need to fix properly instead than trust on such hackish solution.
- Fix a bug where returning (with an error) from dounmount() was still
leaving the MNTK_MWAIT flag on even if it the waiters were actually
woken up. Just a place in vfs_mount_destroy() is left because it is
going to recycle the structure in any case, so it doesn't matter.
- Remove the markercnt refcount as it is useless.
This patch modifies VFS ABI and breaks KPI for vfs_busy() so manpages and
__FreeBSD_version will be modified accordingly.
Discussed with: kib
Tested by: pho
to add more V* constants, and the variables changed by this patch were often
being assigned to mode_t variables, which is 16 bit.
Approved by: rwatson (mentor)
In particular following functions KPI results modified:
- bufobj_invalbuf()
- bufsync()
and BO_SYNC() "virtual method" of the buffer objects set.
Main consumers of bufobj functions are affected by this change too and,
in particular, functions which changed their KPI are:
- vinvalbuf()
- g_vfs_close()
Due to the KPI breakage, __FreeBSD_version will be bumped in a later
commit.
As a side note, please consider just temporary the 'curthread' argument
passing to VOP_SYNC() (in bufsync()) as it will be axed out ASAP
Reviewed by: kib
Tested by: Giovanni Trematerra <giovanni dot trematerra at gmail dot com>
from the vimage project, as per plan established at devsummit 08/08:
http://wiki.freebsd.org/Image/Notes200808DevSummit
Introduce INIT_VNET_*() initializer macros, VNET_FOREACH() iterator
macros, and CURVNET_SET() context setting macros, all currently
resolving to NOPs.
Prepare for virtualization of selected SYSCTL objects by introducing a
family of SYSCTL_V_*() macros, currently resolving to their global
counterparts, i.e. SYSCTL_V_INT() == SYSCTL_INT().
Move selected #defines from sys/sys/vimage.h to newly introduced header
files specific to virtualized subsystems (sys/net/vnet.h,
sys/netinet/vinet.h etc.).
All the changes are verified to have zero functional impact at this
point in time by doing MD5 comparision between pre- and post-change
object files(*).
(*) netipsec/keysock.c did not validate depending on compile time options.
Implemented by: julian, bz, brooks, zec
Reviewed by: julian, bz, brooks, kris, rwatson, ...
Approved by: julian (mentor)
Obtained from: //depot/projects/vimage-commit2/...
X-MFC after: never
Sponsored by: NLnet Foundation, The FreeBSD Foundation
unmounts. When we upgrade a vnode lock from shared to exclusive during
a name cache lookup, fail the lookup with EBADF if the vnode is invalidated
while we are waiting for the exclusive lock.
Also, for correctness (though I'm not sure it can occur in practice),
downgrade an exclusively locked vnode if it should be share locked.
Tested by: pho
initialize the vattr structure in VOP_GETATTR() with VATTR_NULL(),
vattr_null() or by zeroing it. Remove these to allow preinitialization
of fields work in vn_stat(). This is needed to get birthtime initialized
correctly.
Submitted by: Jaakko Heinonen <jh saunalahti fi>
Discussed on: freebsd-fs
MFC after: 1 month
items of the nmount() iovec. This will allow us to move
away from gathering up all the NFS mount options as a single
"struct nfs_args" to be passed down through nmount().
This will make adding new NFS mount options much easier.
Many, many thanks to Doug Rabson, who took my initial patches and
cleaned them up.
Reviewed by: dfr
MFC after: 3 months
virtualization work done by Marko Zec (zec@).
This is the first in a series of commits over the course
of the next few weeks.
Mark all uses of global variables to be virtualized
with a V_ prefix.
Use macros to map them back to their global names for
now, so this is a NOP change only.
We hope to have caught at least 85-90% of what is needed
so we do not invalidate a lot of outstanding patches again.
Obtained from: //depot/projects/vimage-commit2/...
Reviewed by: brooks, des, ed, mav, julian,
jamie, kris, rwatson, zec, ...
(various people I forgot, different versions)
md5 (with a bit of help)
Sponsored by: NLnet Foundation, The FreeBSD Foundation
X-MFC after: never
V_Commit_Message_Reviewed_By: more people than the patch
The kernel has a special wchan called `lbolt', which is triggered each
second. It doesn't seem to be used a lot and it seems pretty redundant,
because we can specify a timeout value to the *sleep() routines. In an
attempt to eventually remove lbolt, make the NFS/RPC code use a timeout
of `hz' when trying to reconnect.
Only the TTY code (not MPSAFE TTY) and the VFS syncer seem to use lbolt
now.
Reviewed by: attilio, jhb
Approved by: philip (mentor), alfred, dfr
to global hostname and domainname variables. Where necessary, copy
to or from a stack-local buffer before performing copyin() or
copyout(). A few uses, such as in cd9660 and daemon_saver, remain
under-synchronized and will require further updates.
Correct a bug in which a failed copyin() of domainname would leave
domainname potentially corrupted.
MFC after: 3 weeks
provides the correct semantics for flock(2) style locks which are used by the
lockf(1) command line tool and the pidfile(3) library. It also implements
recovery from server restarts and ensures that dirty cache blocks are written
to the server before obtaining locks (allowing multiple clients to use file
locking to safely share data).
Sponsored by: Isilon Systems
PR: 94256
MFC after: 2 weeks
Anyway, in the edge case the flushing happens and the while is no more
executed, nfs_flush() (and nfs4_flush()) can return with a wrong
err value of ENOLCK.
Bring it back to 0, as we expect to have for that case.
Reported by: kris
Reviewed by: kib
This particular implementation is designed to be fully backwards compatible
and to be MFC-able to 7.x (and 6.x)
Currently the only protocol that can make use of the multiple tables is IPv4
Similar functionality exists in OpenBSD and Linux.
From my notes:
-----
One thing where FreeBSD has been falling behind, and which by chance I
have some time to work on is "policy based routing", which allows
different
packet streams to be routed by more than just the destination address.
Constraints:
------------
I want to make some form of this available in the 6.x tree
(and by extension 7.x) , but FreeBSD in general needs it so I might as
well do it in -current and back port the portions I need.
One of the ways that this can be done is to have the ability to
instantiate multiple kernel routing tables (which I will now
refer to as "Forwarding Information Bases" or "FIBs" for political
correctness reasons). Which FIB a particular packet uses to make
the next hop decision can be decided by a number of mechanisms.
The policies these mechanisms implement are the "Policies" referred
to in "Policy based routing".
One of the constraints I have if I try to back port this work to
6.x is that it must be implemented as a EXTENSION to the existing
ABIs in 6.x so that third party applications do not need to be
recompiled in timespan of the branch.
This first version will not have some of the bells and whistles that
will come with later versions. It will, for example, be limited to 16
tables in the first commit.
Implementation method, Compatible version. (part 1)
-------------------------------
For this reason I have implemented a "sufficient subset" of a
multiple routing table solution in Perforce, and back-ported it
to 6.x. (also in Perforce though not always caught up with what I
have done in -current/P4). The subset allows a number of FIBs
to be defined at compile time (8 is sufficient for my purposes in 6.x)
and implements the changes needed to allow IPV4 to use them. I have not
done the changes for ipv6 simply because I do not need it, and I do not
have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it.
Other protocol families are left untouched and should there be
users with proprietary protocol families, they should continue to work
and be oblivious to the existence of the extra FIBs.
To understand how this is done, one must know that the current FIB
code starts everything off with a single dimensional array of
pointers to FIB head structures (One per protocol family), each of
which in turn points to the trie of routes available to that family.
The basic change in the ABI compatible version of the change is to
extent that array to be a 2 dimensional array, so that
instead of protocol family X looking at rt_tables[X] for the
table it needs, it looks at rt_tables[Y][X] when for all
protocol families except ipv4 Y is always 0.
Code that is unaware of the change always just sees the first row
of the table, which of course looks just like the one dimensional
array that existed before.
The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign()
are all maintained, but refer only to the first row of the array,
so that existing callers in proprietary protocols can continue to
do the "right thing".
Some new entry points are added, for the exclusive use of ipv4 code
called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(),
which have an extra argument which refers the code to the correct row.
In addition, there are some new entry points (currently called
rtalloc_fib() and friends) that check the Address family being
looked up and call either rtalloc() (and friends) if the protocol
is not IPv4 forcing the action to row 0 or to the appropriate row
if it IS IPv4 (and that info is available). These are for calling
from code that is not specific to any particular protocol. The way
these are implemented would change in the non ABI preserving code
to be added later.
One feature of the first version of the code is that for ipv4,
the interface routes show up automatically on all the FIBs, so
that no matter what FIB you select you always have the basic
direct attached hosts available to you. (rtinit() does this
automatically).
You CAN delete an interface route from one FIB should you want
to but by default it's there. ARP information is also available
in each FIB. It's assumed that the same machine would have the
same MAC address, regardless of which FIB you are using to get
to it.
This brings us as to how the correct FIB is selected for an outgoing
IPV4 packet.
Firstly, all packets have a FIB associated with them. if nothing
has been done to change it, it will be FIB 0. The FIB is changed
in the following ways.
Packets fall into one of a number of classes.
1/ locally generated packets, coming from a socket/PCB.
Such packets select a FIB from a number associated with the
socket/PCB. This in turn is inherited from the process,
but can be changed by a socket option. The process in turn
inherits it on fork. I have written a utility call setfib
that acts a bit like nice..
setfib -3 ping target.example.com # will use fib 3 for ping.
It is an obvious extension to make it a property of a jail
but I have not done so. It can be achieved by combining the setfib and
jail commands.
2/ packets received on an interface for forwarding.
By default these packets would use table 0,
(or possibly a number settable in a sysctl(not yet)).
but prior to routing the firewall can inspect them (see below).
(possibly in the future you may be able to associate a FIB
with packets received on an interface.. An ifconfig arg, but not yet.)
3/ packets inspected by a packet classifier, which can arbitrarily
associate a fib with it on a packet by packet basis.
A fib assigned to a packet by a packet classifier
(such as ipfw) would over-ride a fib associated by
a more default source. (such as cases 1 or 2).
4/ a tcp listen socket associated with a fib will generate
accept sockets that are associated with that same fib.
5/ Packets generated in response to some other packet (e.g. reset
or icmp packets). These should use the FIB associated with the
packet being reponded to.
6/ Packets generated during encapsulation.
gif, tun and other tunnel interfaces will encapsulate using the FIB
that was in effect withthe proces that set up the tunnel.
thus setfib 1 ifconfig gif0 [tunnel instructions]
will set the fib for the tunnel to use to be fib 1.
Routing messages would be associated with their
process, and thus select one FIB or another.
messages from the kernel would be associated with the fib they
refer to and would only be received by a routing socket associated
with that fib. (not yet implemented)
In addition Netstat has been edited to be able to cope with the
fact that the array is now 2 dimensional. (It looks in system
memory using libkvm (!)). Old versions of netstat see only the first FIB.
In addition two sysctls are added to give:
a) the number of FIBs compiled in (active)
b) the default FIB of the calling process.
Early testing experience:
-------------------------
Basically our (IronPort's) appliance does this functionality already
using ipfw fwd but that method has some drawbacks.
For example,
It can't fully simulate a routing table because it can't influence the
socket's choice of local address when a connect() is done.
Testing during the generating of these changes has been
remarkably smooth so far. Multiple tables have co-existed
with no notable side effects, and packets have been routes
accordingly.
ipfw has grown 2 new keywords:
setfib N ip from anay to any
count ip from any to any fib N
In pf there seems to be a requirement to be able to give symbolic names to the
fibs but I do not have that capacity. I am not sure if it is required.
SCTP has interestingly enough built in support for this, called VRFs
in Cisco parlance. it will be interesting to see how that handles it
when it suddenly actually does something.
Where to next:
--------------------
After committing the ABI compatible version and MFCing it, I'd
like to proceed in a forward direction in -current. this will
result in some roto-tilling in the routing code.
Firstly: the current code's idea of having a separate tree per
protocol family, all of the same format, and pointed to by the
1 dimensional array is a bit silly. Especially when one considers that
there is code that makes assumptions about every protocol having the
same internal structures there. Some protocols don't WANT that
sort of structure. (for example the whole idea of a netmask is foreign
to appletalk). This needs to be made opaque to the external code.
My suggested first change is to add routing method pointers to the
'domain' structure, along with information pointing the data.
instead of having an array of pointers to uniform structures,
there would be an array pointing to the 'domain' structures
for each protocol address domain (protocol family),
and the methods this reached would be called. The methods would have
an argument that gives FIB number, but the protocol would be free
to ignore it.
When the ABI can be changed it raises the possibilty of the
addition of a fib entry into the "struct route". Currently,
the structure contains the sockaddr of the desination, and the resulting
fib entry. To make this work fully, one could add a fib number
so that given an address and a fib, one can find the third element, the
fib entry.
Interaction with the ARP layer/ LL layer would need to be
revisited as well. Qing Li has been working on this already.
This work was sponsored by Ironport Systems/Cisco
Reviewed by: several including rwatson, bz and mlair (parts each)
Obtained from: Ironport systems/Cisco
for better structure.
Much of this is related to <sys/clock.h>, which should really have
been called <sys/calendar.h>, but unless and until we need the name,
the repocopy can wait.
In general the kernel does not know about minutes, hours, days,
timezones, daylight savings time, leap-years and such. All that
is theoretically a matter for userland only.
Parts of kernel code does however care: badly designed filesystems
store timestamps in local time and RTC chips almost universally
track time in a YY-MM-DD HH:MM:SS format, and sometimes in local
timezone instead of UTC. For this we have <sys/clock.h>
<sys/time.h> on the other hand, deals with time_t, timeval, timespec
and so on. These know only seconds and fractions thereof.
Move inittodr() and resettodr() prototypes to <sys/time.h>.
Retain the names as it is one of the few surviving PDP/VAX references.
Move startrtclock() to <machine/clock.h> on relevant platforms, it
is a MD call between machdep.c/clock.c. Remove references to it
elsewhere.
Remove a lot of unnecessary <sys/clock.h> includes.
Move the machdep.disable_rtc_set sysctl to subr_rtc.c where it belongs.
XXX: should be kern.disable_rtc_set really, it's not MD.
filesystem-specific vnode data to the struct vnode. Provide the
default implementation for the vop_advlock and vop_advlockasync.
Purge the locks on the vnode reclaim by using the lf_purgelocks().
The default implementation is augmented for the nfs and smbfs.
In the nfs_advlock, push the Giant inside the nfs_dolock.
Before the change, the vop_advlock and vop_advlockasync have taken the
unlocked vnode and dereferenced the fs-private inode data, racing with
with the vnode reclamation due to forced unmount. Now, the vop_getattr
under the shared vnode lock is used to obtain the inode size, and
later, in the lf_advlockasync, after locking the vnode interlock, the
VI_DOOMED flag is checked to prevent an operation on the doomed vnode.
The implementation of the lf_purgelocks() is submitted by dfr.
Reported by: kris
Tested by: kris, pho
Discussed with: jeff, dfr
MFC after: 2 weeks
user-mode lock manager, build a kernel with the NFSLOCKD option and
add '-k' to 'rpc_lockd_flags' in rc.conf.
Highlights include:
* Thread-safe kernel RPC client - many threads can use the same RPC
client handle safely with replies being de-multiplexed at the socket
upcall (typically driven directly by the NIC interrupt) and handed
off to whichever thread matches the reply. For UDP sockets, many RPC
clients can share the same socket. This allows the use of a single
privileged UDP port number to talk to an arbitrary number of remote
hosts.
* Single-threaded kernel RPC server. Adding support for multi-threaded
server would be relatively straightforward and would follow
approximately the Solaris KPI. A single thread should be sufficient
for the NLM since it should rarely block in normal operation.
* Kernel mode NLM server supporting cancel requests and granted
callbacks. I've tested the NLM server reasonably extensively - it
passes both my own tests and the NFS Connectathon locking tests
running on Solaris, Mac OS X and Ubuntu Linux.
* Userland NLM client supported. While the NLM server doesn't have
support for the local NFS client's locking needs, it does have to
field async replies and granted callbacks from remote NLMs that the
local client has contacted. We relay these replies to the userland
rpc.lockd over a local domain RPC socket.
* Robust deadlock detection for the local lock manager. In particular
it will detect deadlocks caused by a lock request that covers more
than one blocking request. As required by the NLM protocol, all
deadlock detection happens synchronously - a user is guaranteed that
if a lock request isn't rejected immediately, the lock will
eventually be granted. The old system allowed for a 'deferred
deadlock' condition where a blocked lock request could wake up and
find that some other deadlock-causing lock owner had beaten them to
the lock.
* Since both local and remote locks are managed by the same kernel
locking code, local and remote processes can safely use file locks
for mutual exclusion. Local processes have no fairness advantage
compared to remote processes when contending to lock a region that
has just been unlocked - the local lock manager enforces a strict
first-come first-served model for both local and remote lockers.
Sponsored by: Isilon Systems
PR: 95247 107555 115524 116679
MFC after: 2 weeks
Removed dead code that assumed that M_TRYWAIT can return NULL; it's not true
since the advent of MBUMA.
Reviewed by: arch
There are ongoing disputes as to whether we want to switch to directly using
UMA flags M_WAITOK/M_NOWAIT for mbuf(9) allocation.
BO_LOCK/UNLOCK/MTX when manipulating the bufobj.
- Create a new lock in the bufobj to lock bufobj fields independently.
This leaves the vnode interlock as an 'identity' lock while the bufobj
is an io lock. The bufobj lock is ordered before the vnode interlock
and also before the mnt ilock.
- Exploit this new lock order to simplify softdep_check_suspend().
- A few sync related functions are marked with a new XXX to note that
we may not properly interlock against a non-zero bv_cnt when
attempting to sync all vnodes on a mountlist. I do not believe this
race is important. If I'm wrong this will make these locations easier
to find.
Reviewed by: kib (earlier diff)
Tested by: kris, pho (earlier diff)
after each SYSINIT() macro invocation. This makes a number of
lightweight C parsers much happier with the FreeBSD kernel
source, including cflow's prcc and lxr.
MFC after: 1 month
Discussed with: imp, rink
mount options that mount_nfs could pass down, if it passed
down string mount options. Right now, mount_nfs jut passes
down a single mount option named "nfs_args" with a fully
initialized 'struct nfs_args'.
In future commits, we will add code to the kernel for parsing stringified
NFS mount options, so that we can convert mount_nfs to pass string options
from userspace to kernel, instead of an initialized struct nfs_args.
the same way that it is default initialized in revision 1.77 of mount_nfs.c.
Right now, this is a no-op, because currently we initialize
struct nfs_args in mount_nfs in userspace, and pass it
down into the kernel via nmount(), so we overwrite whatever we initialize
here with the value passed in from userspace.
However, this lays the groundwork for moving away from passing
struct nfs_args from userspace to kernel via nmount(), so that we
can instead pass string mount options via nmount() which can be parsed in
the kernel. This will make it easier to add new NFS mount options.
always curthread.
As KPI gets broken by this patch, manpages and __FreeBSD_version will be
updated by further commits.
Tested by: Andrea Barberio <insomniac at slackware dot it>
namespace in order to handle lockmgr fields in a controlled way instead
than spreading all around bogus stubs:
- VN_LOCK_AREC() allows lock recursion for a specified vnode
- VN_LOCK_ASHARE() allows lock sharing for a specified vnode
In FFS land:
- BUF_AREC() allows lock recursion for a specified buffer lock
- BUF_NOREC() disallows recursion for a specified buffer lock
Side note: union_subr.c::unionfs_node_update() is the only other function
directly handling lockmgr fields. As this is not simple to fix, it has
been left behind as "sole" exception.
file system. In particular, stop overwriting mount point
flags in nfs_mountdiskless() because now they are set
elsewhere. (They were _initialized_ by that function in
the 4.4BSD days, when mount structures were not allocated
in a centralized manner -- see rev. 1.1 of this file.)
Fix nfs_mount(), which happened to depend on the loss of
MNT_ROOTFS when it came to update handling.
Also note that mountnfs() no longer handles updates. Now
they shouldn't reach this function, so printf a diagnostic
message if that happens due to a coding error.
A couple of notes for this:
* WITNESS support, when enabled, is only used for shared locks in order
to avoid problems with the "disowned" locks
* KA_HELD and KA_UNHELD only exists in the lockmgr namespace in order
to assert for a generic thread (not curthread) owning or not the
lock. Really, this kind of check is bogus but it seems very
widespread in the consumers code. So, for the moment, we cater this
untrusted behaviour, until the consumers are not fixed and the
options could be removed (hopefully during 8.0-CURRENT lifecycle)
* Implementing KA_HELD and KA_UNHELD (not surported natively by
WITNESS) made necessary the introduction of LA_MASKASSERT which
specifies the range for default lock assertion flags
* About other aspects, lockmgr_assert() follows exactly what other
locking primitives offer about this operation.
- Build real assertions for buffer cache locks on the top of
lockmgr_assert(). They can be used with the BUF_ASSERT_*(bp)
paradigm.
- Add checks at lock destruction time and use a cookie for verifying
lock integrity at any operation.
- Redefine BUF_LOCKFREE() in order to not use a direct assert but
let it rely on the aforementioned destruction time check.
KPI results evidently broken, so __FreeBSD_version bumping and
manpage update result necessary and will be committed soon.
Side note: lockmgr_assert() will be used soon in order to implement
real assertions in the vnode namespace replacing the legacy and still
bogus "VOP_ISLOCKED()" way.
Tested by: kris (earlier version)
Reviewed by: jhb
nfs_xid_gen() function instead of duplicating the logic in both
nfsm_rpchead() and the NFS3ERR_JUKEBOX handling in nfs_request().
MFC after: 1 week
Submitted by: mohans (a long while ago)
historical relic, and are no longer appropriate for either LAN or WAN
mounting. At modern (gigabit and 10 gigabit) LAN speeds packet loss
from socket buffer fill events is common, and sequence numbers wrap
quickly enough that data corruption is possible. TCP solves both of
these problems without imposing significant overhead.
MFC after: 1 month
owned by a NULL owner. This will lead consequent VOP_ISLOCKED() present
into nfs_upgrade_vnlock() to panic as it only acquire curthread now.
Fix nfs_upgrade_vnlock() and nfs_downgrade_vnlock() in order to not use
more the struct thread pointer passed as argument (as it is really nomore
required there as vn_lock() and VOP_UNLOCK doesn't get the lock more).
Using curthread, in place, doesn't get ambiguity as LK_EXCLOTHER should
be handled as a "not locked" request by both functions.
Reported by: kris
Tested by: kris
Reviewed by: ups
VOP_ISLOCKED(arg, curthread). Now, VOP_ISLOCKED() and lockstatus() should
only acquire curthread as argument; this will lead in axing the additional
argument from both functions, making the code cleaner.
Reviewed by: jeff, kib
- Remove the "thread" argument from the lockmgr() function as it is
always curthread now
- Axe lockcount() function as it is no longer used
- Axe LOCKMGR_ASSERT() as it is bogus really and no currently used.
Hopefully this will be soonly replaced by something suitable for it.
- Remove the prototype for dumplockinfo() as the function is no longer
present
Addictionally:
- Introduce a KASSERT() in lockstatus() in order to let it accept only
curthread or NULL as they should only be passed
- Do a little bit of style(9) cleanup on lockmgr.h
KPI results heavilly broken by this change, so manpages and
FreeBSD_version will be modified accordingly by further commits.
Tested by: matteo
lockmgr lkp, when held in exclusive mode, is recursed
- Introduce the function BUF_RECURSED() which does the same for bufobj
locks based on the top of lockmgr_recursed()
- Introduce the function BUF_ISLOCKED() which works like the counterpart
VOP_ISLOCKED(9), showing the state of lockmgr linked with the bufobj
BUF_RECURSED() and BUF_ISLOCKED() entirely replace the usage of bogus
BUF_REFCNT() in a more explicative and SMP-compliant way.
This allows us to axe out BUF_REFCNT() and leaving the function
lockcount() totally unused in our stock kernel. Further commits will
axe lockcount() as well as part of lockmgr() cleanup.
KPI results, obviously, broken so further commits will update manpages
and freebsd version.
Tested by: kris (on UFS and NFS)
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.
KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.
Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>
via a new socket during an NFS operation as that reconnect takes place in
the context of an arbitrary thread with an arbitrary credential. Ideally
we would like to use the mount point's credential for the entire process
of setting up the socket to connect to the NFS server. Since some of the
APIs (sobind(), etc.) only take a thread pointer and infer the credential
from that instead of a direct credential, work around the problem by
temporarily changing the current thread's credential to that of the mount
point while connecting the socket and then reverting back to the original
credential when we are done.
Reviewed by: rwatson
Tested on: UDP, TCP, TCP with forced reconnect
soconnect()) instead of &thread0 when establishing a connection to the NFS
server. Otherwise inconsistent credentials may be used when setting up
the NFS socket.
MFC after: 1 week
Reviewed by: rwatson
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.
Manpage and FreeBSD_version will be updated through further commits.
As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.
Tested by: Diego Sardina <siarodx at gmail dot com>,
Andrea Di Pasquale <whyx dot it at gmail dot com>
server-side RPC retranmission cache for non-idempotent operations: these
hacks substituted 0 (success) for the expected EEXIST in the event that
a target name already existed for LINK, SYMLINK, and MKDIR operations,
under the assumption that EEXIST represented a second application of the
original RPC rather than a true failure.
Background: certain NFS operations (in this case, LINK, SYMLINK, and
MKDIR) are not idempotent, as they leave behind persisting state on the
server that prevents them from being replayed without an error;if an UDP
RPC reply is lost leading to a retransmission by theclient, the second
reply will return EEXIST rather than success, asthe new object has
already been created. The NFS client previouslysilently mapped the
EEXIST return into success to paper over thisproblem.
However, in all modern NFS server implementations, a reply cache is kept
in order to retransmit the original reply to a retransmitted request,
rather than performing the operation a second time, allowing this hack
to be avoided. This allows link()-based filelocking over NFS to operate
correctly, as an application requestingthe creation of a new link for a
file to tell if it succeededatomically or not.
Other NFS clients, including Solaris and Linux, generally follow this
behavior for the same reasons. Most clients also now default to TCP,
which also helps avoid the issue of retransmitted but non-idempotent
requests in most cases.
Reported by: Adam McDougall <mcdouga9 at egr dot msu dot edu>,
Timo Sirainen <tss at iki dot fi>
Reviewed by: mohans
MFC after: 1 week
noatime, noexec, suiddir, nosuid, nosymfollow, union,
noclusterr, noclusterw, multilabel, acls, force, update,
async. These options correspond to MOPT_STDOPTS, MOPT_FORCE, MOPT_UPDATE,
and MOPT_ASYNC.
Currently, mount_nfs converts these "-o" options from strings
to MNT_ flags via getmntopts(),
and passes the flags from userspace to the kernel.
This change will allow us in future to pass these mount options
as strings directly to the kernel via nmount() when doing NFS mounts.
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.
I'd LOVE to do this rename in 7.0 so that we can eventually MFC the
new kthread_xxx() calls.
- Eliminate the hideous nfs_sndlock that serialized NFS/TCP request senders
thru the sndlock.
- Institute a new nfs_connectlock that serializes NFS/TCP reconnects. Add
logic to wait for pending request senders to finish sending before
reconnecting. Dial down the sb_timeo for NFS/TCP sockets to 1 sec.
- Break out the nfs xid manipulation under a new nfs xid lock, rather than
over loading the nfs request lock for this purpose.
- Fix some of the locking in nfs_request.
Many thanks to Kris Kennaway for his help with this and for initiating the
MP scaling analysis and work. Kris also tested this patch thorougly.
Approved by: re@ (Ken Smith)
timeout occurring at exactly the same time. If this happens, the nfsiod
exits although there may be a queued async IO request for it.
Found by : Kris Kennaway
Approved by: re
previously conditionally acquired Giant based on debug.mpsafenet. As that
has now been removed, they are no longer required. Removing them
significantly simplifies error-handling in the socket layer, eliminated
quite a bit of unwinding of locking in error cases.
While here clean up the now unneeded opt_net.h, which previously was used
for the NET_WITH_GIANT kernel option. Clean up some related gotos for
consistency.
Reviewed by: bz, csjp
Tested by: kris
Approved by: re (kensmith)
nfsnode could lead to attrs being stale. One example (that we
ran into) was a READDIR+, WRITE. The responses came back in
order, but the attrs from the WRITE were loaded before the
attrs from the READDIR+, leading to the wrong size from being
read on the next stat() call.
MFC after: 1 week
Submitted by: mohans
Approved by: re (kensmith)
recoverable and unrecoverable. For the former, we redirty the
buffer and hang onto it for future retries. For the latter (eg.
ESTALE), we discard the buffer and return the error back to the
user on the next syscall. This fixes a number of vfs panics and
fixes having a large number of dirty buffers (that cannot be
written out and reclaimed) from hanging around. Thanks to ups@
for discussions on this issue.
Reported by: kris, Kai, others
Approved by: re (kensmith)
Now, we assume no more sched_lock protection for some of them and use the
distribuited loads method for vmmeter (distribuited through CPUs).
Reviewed by: alc, bde
Approved by: jeff (mentor)
td_ru. This removes the requirement for per-process synchronization in
statclock() and mi_switch(). This was previously supported by
sched_lock which is going away. All modifications to rusage are now
done in the context of the owning thread. reads proceed without locks.
- Aggregate exiting threads rusage in thread_exit() such that the exiting
thread's rusage is not lost.
- Provide a new routine, rufetch() to fetch an aggregate of all rusage
structures from all threads in a process. This routine must be used
in any place requiring a rusage from a process prior to it's exit. The
exited process's rusage is still available via p_ru.
- Aggregate tick statistics only on demand via rufetch() or when a thread
exits. Tick statistics are kept in the thread and protected by sched_lock
until it exits.
Initial patch by: attilio
Reviewed by: attilio, bde (some objections), arch (mostly silent)
Probabilly, a general approach is not the better solution here, so we should
solve the sched_lock protection problems separately.
Requested by: alc
Approved by: jeff (mentor)
lock and unlock conditionally, not just set the flag on it conditionally.
In practice, this bug couldn't manifest, as in the current revision of
the code, no callers pass a NULL rep.
CID: 1416
Found with: Coverity Prevent(tm)
vmcnts. This can be used to abstract away pcpu details but also changes
to use atomics for all counters now. This means sched lock is no longer
responsible for protecting counts in the switch routines.
Contributed by: Attilio Rao <attilio@FreeBSD.org>
- Fix for a bug where a close would not wait for all (directio)
dirty buffers to drain. The nfsnode was not marked NMODIFIED
when there were directio dirtied buffers pending, causing this.
- No reason to vhold/vrele the vp when enqueueing DirectIO requests
for the nfsiods. The vnode can't really go way since the close
has to wait for these requests to drain.
MFC after: 1 week
Submitted by: mohans
- Replace PRIV_NFSD with PRIV_NFS_DAEMON, add PRIV_NFS_LOCKD.
- Use PRIV_NFS_DAEMON in the NFS server.
- In the NFS client, move the privilege check from nfslockdans(), which
occurs every time a write is performed on /dev/nfslock, and instead do it
in nfslock_open() just once. This allows us to avoid checking the saved
uid for root, and just use the effective on open. Use PRIV_NFS_LOCKD.
late stages of unmount). On failure, the vnode is recycled.
Add insmntque1(), to allow for file system specific cleanup when
recycling vnode on failure.
Change getnewvnode() to no longer call insmntque(). Previously,
embryonic vnodes were put onto the list of vnode belonging to a file
system, which is unsafe for a file system marked MPSAFE.
Change vfs_hash_insert() to no longer lock the vnode. The caller now
has that responsibility.
Change most file systems to lock the vnode and call insmntque() or
insmntque1() after a new vnode has been sufficiently setup. Handle
failed insmntque*() calls by propagating errors to callers, possibly
after some file system specific cleanup.
Approved by: re (kensmith)
Reviewed by: kib
In collaboration with: kib
GETATTRs being generated - one from lookup()/namei() and the other
from nfs_open() (for cto consistency). This change eliminates the
GETATTR in nfs_open() if an otw GETATTR was done from the namei()
path. Instead of extending the vop interface, we timestamp each attr
load, and use this to detect whether a GETATTR was done from namei()
for this syscall. Introduces a thread-local variable that counts the
syscalls made by the thread and uses <pid, tid, thread syscalls> as
the attrload timestamp. Thanks to jhb@ and peter@ for a discussion on
thread state that could be used as the timestamp with minimal overhead.
