shared uses of a resource are recorded on a sub-list hanging off
a main resource object on a main resource list;
without this change a shared resource (e.g. irq) is reported only
once by devinfo -r/-u;
with this change the resource is reported for each driver that
allocates it (which is even more than what vmstat -i -a reports).
Approved by: jhb (mentor)
affinity for the interrupt thread, and requesting that underlying
hardware direct interrupts to the CPU. For software interrupt
threads, implement a no-op interrupt event binder that returns
success, so that the interrupt management code will just set the
ithread's affinity and succeed.
Reviewed by: jhb
MFC after: 1 week
These sysctls don't need any form of locking. At least cp_times is used
by powerd very often, which means I get 50% less calls to non-MPSAFE
sysctls on my system. The other 50% is consumed by dev.cpu.0.freq, but
this seems to need Giant for Newbus.
Provide a more descriptive comment.
Eliminate dead code. The page cannot possibly have PG_ZERO set.
Eliminate unnecessary blank lines.
Reviewed by: tegge
This makes siginfo output look a lot better when pressing it the first
time when in sh(1), for example:
$ load: 0.00 cmd: sh 1945 [ttyin] 3.94r 0.00u 0.00s 0% 1960k
load: 0.00 cmd: sh 1945 [ttyin] 4.19r 0.00u 0.00s 0% 1960k
will now become:
$
load: 0.00 cmd: sh 1945 [ttyin] 3.94r 0.00u 0.00s 0% 1960k
load: 0.00 cmd: sh 1945 [ttyin] 4.19r 0.00u 0.00s 0% 1960k
- Only pick up PROC_LOCK once, which means we can drop the PGRP_LOCK
right after picking up PROC_LOCK for the first time.
- Print the process real time, making it consistent with tools like
time(1).
- Use `p' and `td' to reference the process/thread we are going to
print. Only use pick-variables inside the loops. We already did this
for the threads, but not the processes.
that expect that oldlen is filled with required buffer length even when
supplied buffer is too short and returned error is ENOMEM.
Redo the fix for kern.proc.filedesc, by reverting the req->oldidx when
remaining buffer space is too short for the current kinfo_file structure.
Also, only ignore ENOMEM. We have to convert ENOMEM to no error condition
to keep existing interface for the sysctl, though.
Reported by: ed, Florian Smeets <flo kasimir com>
Tested by: pho
sysctl requests to avoid wiring too much user memory. Only grab this
lock if the user's old buffer is larger than a page as a tradeoff to
allow more concurrency for common small requests.
- Just use a shared lock on the sysctl tree for user sysctl requests now.
MFC after: 1 week
error due to copyout failure or short buffer.
The later breaks the usermode iterators of the sysctl results that pack
arbitrary number of variable-sized structures. Iterator expects that
kernel filled exactly oldlen bytes, and tries to interpret half-filled
or garbage structure at the end of the buffer. In particular,
kinfo_getfile(3) segfaulted.
Reported and tested by: pho
MFC after: 3 weeks
fget_unlocked().
- Save old file descriptor tables created on expansion until
the entire descriptor table is freed so that pointers may be
followed without regard for expanders.
- Mark the file zone as NOFREE so we may attempt to reference
potentially freed files.
- Convert several fget_locked() users to fget_unlocked(). This
requires us to manage reference counts explicitly but reduces
locking overhead in the common case.
following changes:
Rename vfs_page_set_valid() to vfs_page_set_validclean() to reflect
what this function actually does. Suggested by: tegge
Introduce a new version of vfs_page_set_valid() that does no more than
what the function's name implies. Specifically, it does not update
the page's dirty mask, and thus it does not require the page queues
lock to be held.
Update two of the three callers to the old vfs_page_set_valid() to
call vfs_page_set_validclean() instead because they actually require
the page's dirty mask to be cleared.
Introduce vm_page_set_valid().
Reviewed by: tegge
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.
suffer from the race condition that motivated revision 1.94. Consequently,
the work-around that was implemented by revision 1.94 is no longer needed.
Moreover, reverting this work-around eliminates the need for
vfs_busy_pages() to acquire the page queues lock when preparing a buffer
for read.
Reviewed by: tegge
Credential might need to hang around longer than its parent and be used
outside of mnt_explock scope controlling netcred lifetime. Use separate
reference-counted ucred allocated separately instead.
While there, extend mnt_explock coverage in vfs_stdexpcheck and clean-up
some unused declarations in new NFS code.
Reported by: John Hickey
PR: kern/133439
Reviewed by: dfr, kib
virtualized instances of hostname and domainname, as well as a new top-level
virtualization struct vimage, which holds pointers to struct vnet and struct
vprocg. Struct vprocg is likely to become replaced in the near future with
a new jail management API import.
As a consequence of this change, change struct ucred to point to a struct
vimage, instead of directly pointing to a vnet.
Merge vnet / vimage / ucred refcounting infrastructure from p4 / vimage
branch.
Permit kldload / kldunload operations to be executed only from the default
vimage context.
This change should have no functional impact on nooptions VIMAGE kernel
builds.
Reviewed by: bz
Approved by: julian (mentor)
OSD-based jail extensions. This allows the Linux MIB to accessed via
jail_set and jail_get, and serves as a demonstration of adding jail support
to a module.
Reviewed by: dchagin, kib
Approved by: bz (mentor)
It turns out if we called cfmakeraw() on a TTY with only a rint handler
in place, it could inject data into the TTY, even though it should be
redirected. Always take a look at the hooks before looking at the
termios flags.
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)
active network stack instance. Turning on options VIMAGE at compile
time yields the following changes relative to default kernel build:
1) V_ accessor macros for virtualized variables resolve to structure
fields via base pointers, instead of being resolved as fields in global
structs or plain global variables. As an example, V_ifnet becomes:
options VIMAGE: ((struct vnet_net *) vnet_net)->_ifnet
default build: vnet_net_0._ifnet
options VIMAGE_GLOBALS: ifnet
2) INIT_VNET_* macros will declare and set up base pointers to be used
by V_ accessor macros, instead of resolving to whitespace:
INIT_VNET_NET(ifp->if_vnet); becomes
struct vnet_net *vnet_net = (ifp->if_vnet)->mod_data[VNET_MOD_NET];
3) Memory for vnet modules registered via vnet_mod_register() is now
allocated at run time in sys/kern/kern_vimage.c, instead of per vnet
module structs being declared as globals. If required, vnet modules
can now request the framework to provide them with allocated bzeroed
memory by filling in the vmi_size field in their vmi_modinfo structures.
4) structs socket, ifnet, inpcbinfo, tcpcb and syncache_head are
extended to hold a pointer to the parent vnet. options VIMAGE builds
will fill in those fields as required.
5) curvnet is introduced as a new global variable in options VIMAGE
builds, always pointing to the default and only struct vnet.
6) struct sysctl_oid has been extended with additional two fields to
store major and minor virtualization module identifiers, oid_v_subs and
oid_v_mod. SYSCTL_V_* family of macros will fill in those fields
accordingly, and store the offset in the appropriate vnet container
struct in oid_arg1.
In sysctl handlers dealing with virtualized sysctls, the
SYSCTL_RESOLVE_V_ARG1() macro will compute the address of the target
variable and make it available in arg1 variable for further processing.
Unused fields in structs vnet_inet, vnet_inet6 and vnet_ipfw have
been deleted.
Reviewed by: bz, rwatson
Approved by: julian (mentor)
interface as nmount(2). Three new system calls are added:
* jail_set, to create jails and change the parameters of existing jails.
This replaces jail(2).
* jail_get, to read the parameters of existing jails. This replaces the
security.jail.list sysctl.
* jail_remove to kill off a jail's processes and remove the jail.
Most jail parameters may now be changed after creation, and jails may be
set to exist without any attached processes. The current jail(2) system
call still exists, though it is now a stub to jail_set(2).
Approved by: bz (mentor)
import from p4 bms_netdev. Summary of changes:
* Connect netinet6/in6_mcast.c to build.
The legacy KAME KPIs are mostly preserved.
* Eliminate now dead code from ip6_output.c.
Don't do mbuf bingo, we are not going to do RFC 2292 style
CMSG tricks for multicast options as they are not required
by any current IPv6 normative reference.
* Refactor transports (UDP, raw_ip6) to do own mcast filtering.
SCTP, TCP unaffected by this change.
* Add ip6_msource, in6_msource structs to in6_var.h.
* Hookup mld_ifinfo state to in6_ifextra, allocate from
domifattach path.
* Eliminate IN6_LOOKUP_MULTI(), it is no longer referenced.
Kernel consumers which need this should use in6m_lookup().
* Refactor IPv6 socket group memberships to use a vector (like IPv4).
* Update ifmcstat(8) for IPv6 SSM.
* Add witness lock order for IN6_MULTI_LOCK.
* Move IN6_MULTI_LOCK out of lower ip6_output()/ip6_input() paths.
* Introduce IP6STAT_ADD/SUB/INC/DEC as per rwatson's IPv4 cleanup.
* Update carp(4) for new IPv6 SSM KPIs.
* Virtualize ip6_mrouter socket.
Changes mostly localized to IPv6 MROUTING.
* Don't do a local group lookup in MROUTING.
* Kill unused KAME prototypes in6_purgemkludge(), in6_restoremkludge().
* Preserve KAME DAD timer jitter behaviour in MLDv1 compatibility mode.
* Bump __FreeBSD_version to 800084.
* Update UPDATING.
NOTE WELL:
* This code hasn't been tested against real MLDv2 queriers
(yet), although the on-wire protocol has been verified in Wireshark.
* There are a few unresolved issues in the socket layer APIs to
do with scope ID propagation.
* There is a LOR present in ip6_output()'s use of
in6_setscope() which needs to be resolved. See comments in mld6.c.
This is believed to be benign and can't be avoided for the moment
without re-introducing an indirect netisr.
This work was mostly derived from the IGMPv3 implementation, and
has been sponsored by a third party.
and it only optimized out an ipi or mwait in very few cases.
- Skip the adaptive idle code when running on SMT or HTT cores. This
just wastes cpu time that could be used on a busy thread on the same
core.
- Rename CG_FLAG_THREAD to CG_FLAG_SMT to be more descriptive. Re-use
CG_FLAG_THREAD to mean SMT or HTT.
Sponsored by: Nokia
root cpuset of that jail.
Processes inside the jail will still be able to change child sets.
A superuser outside of a jail will still be able to change the jail cpuset
and thus limit the number of cpus available to the jail.
Problem reported by: 000.fbsd@quip.cz (Miroslav Lachman)
PR: kern/134050
Reviewed by: jeff
MFC after: 3 weeks
X-MFC: backout r191596
first introduced @ r190909 with a vnet module deregistration
service.
kldunloadable modules, which are currently using vnet_mod_register()
to attach their per-vnet initialization routines to the vnet
initialization framework, should call vnet_mod_deregister() before
acknowledging MOD_UNLOAD requests in their mod_event handlers. Such
changes to the existing code base will follow in subsequent commits.
vnet_mod_deregister() does not check whether departing vnet modules
are registered as prerequisites for another module(s), so it should
be used with care. Currently I'm only aware of vnet modules which
are leafs on module dependency graphs that are kldunloadable.
This change also introduces per-vnet module destructor handler, which
calls vnet's module cleanup function, which (if required) has to be
registered in vnet module's vnet_modinfo_t structure .vmi_idetach
field. Once options VIMAGE becomes operational, the framework will
take care that module's cleanup function become invoked for each
active vnet instance, and that the memory allocated for each instance
gets freed. Currently calls to destructor handlers must always
succeed.
This allows users to increase the maximum amount of pseudo-terminals
without changing any source code. Users must increase UT_LINESIZE before
attempting to increase kern.pts_maxdev.
The main problem is that sbappendrecord_locked() relies on sbcompress()
to set sb_mbtail. This will not happen if sbappendrecord_locked() is
called with mbuf chain made of exactly one mbuf (i.e. m0->m_next == NULL).
In this case sbcompress() will be called with m == NULL and will do
nothing. I'm not entirely sure if m == NULL is a valid argument for
sbcompress(), and, it rather pointless to call it like that, but keep
calling it so it can do SBLASTMBUFCHK().
The problem is triggered by the SOCKBUF_DEBUG kernel option that
enables SBLASTRECORDCHK() and SBLASTMBUFCHK() checks.
PR: kern/126742
Investigated by: pluknet < pluknet -at- gmail -dot- com >
No response from: freebsd-current@, freebsd-bluetooth@
MFC after: 3 days
or ignored SIGCHLD, unconditionally wake up the parent instead of doing
this only when the child is a last child.
This brings us in line with other U**xes that support SA_NOCLDWAIT. If
the parent called waitpid(childpid), then exit of the child should wake
up the parent immediately instead of forcing it to wait for all children
to exit.
Reported by: Alan Ferrency <alan pair com>
Submitted by: Jilles Tjoelker <jilles stack nl>
PR: 108390
MFC after: 2 weeks
In the good old days it was possible to have dev_t's that referred to
nonexistent devices. In these cases devtoname() automatically generated
names. This is no longer possible, so remove this dead code.
Discussed with: kib
Remove the `udev' variable, which has a different type than the original
function argument and si_drv0. The `udev' name is also misleading,
because it is not the number returned by dev2udev(). Rename this
argument to `unit'. It is the same number as returned by dev2unit().
We should still access si_drv0 using dev2unit(). Also change the
KASSERT() to really print the udev instead of the unit number. I suspect
it's still useful to print the unit number, especially for devices that
use clone lists, so keep the unit number in the panic string.
not populated in parent directory if negative entry was being
created, yet entry itself was added to the nc_neg list. It was
possible for parent vnode to get discarded later, leaving negative
entry pointing to now unused memory block.
Reported by: dho
Revewed by: kib
dependency tracking and ordering enforcement.
With this change, per-vnet initialization functions introduced with
r190787 are no longer directly called from traditional initialization
functions (which cc in most cases inlined to pre-r190787 code), but are
instead registered via the vnet framework first, and are invoked only
after all prerequisite modules have been initialized. In the long run,
this framework should allow us to both initialize and dismantle
multiple vnet instances in a correct order.
The problem this change aims to solve is how to replay the
initialization sequence of various network stack components, which
have been traditionally triggered via different mechanisms (SYSINIT,
protosw). Note that this initialization sequence was and still can be
subtly different depending on whether certain pieces of code have been
statically compiled into the kernel, loaded as modules by boot
loader, or kldloaded at run time.
The approach is simple - we record the initialization sequence
established by the traditional mechanisms whenever vnet_mod_register()
is called for a particular vnet module. The vnet_mod_register_multi()
variant allows a single initializer function to be registered multiple
times but with different arguments - currently this is only used in
kern/uipc_domain.c by net_add_domain() with different struct domain *
as arguments, which allows for protosw-registered initialization
routines to be invoked in a correct order by the new vnet
initialization framework.
For the purpose of identifying vnet modules, each vnet module has to
have a unique ID, which is statically assigned in sys/vimage.h.
Dynamic assignment of vnet module IDs is not supported yet.
A vnet module may specify a single prerequisite module at registration
time by filling in the vmi_dependson field of its vnet_modinfo struct
with the ID of the module it depends on. Unless specified otherwise,
all vnet modules depend on VNET_MOD_NET (container for ifnet list head,
rt_tables etc.), which thus has to and will always be initialized
first. The framework will panic if it detects any unresolved
dependencies before completing system initialization. Detection of
unresolved dependencies for vnet modules registered after boot
(kldloaded modules) is not provided.
Note that the fact that each module can specify only a single
prerequisite may become problematic in the long run. In particular,
INET6 depends on INET being already instantiated, due to TCP / UDP
structures residing in INET container. IPSEC also depends on INET,
which will in turn additionally complicate making INET6-only kernel
configs a reality.
The entire registration framework can be compiled out by turning on the
VIMAGE_GLOBALS kernel config option.
Reviewed by: bz
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
It turns out my handling of SIGTTOU and SIGTTIN didn't entirely comply
to the standards. It is true that in the SIGTTOU case we should not
return EIO when the signal is ignored/blocked, but in the SIGTTIN case
we must.
See also: POSIX issue 7 section 11.1.4
the size and cost of name cache entries, but make adding debugging
and tracing easier.
Add SDT DTrace probes for various namecache events:
vfs:namecache:enter:done - new entry in the name cache, passed parent
directory vnode pointer, name added to the cache, and child vnode
pointer.
vfs:namecache:enter_negative:done - new negative entry in the name cache,
passed parent vnode pointer, name added to the cache.
vfs:namecache:fullpath:enter - call to vn_fullpath1() is made, passed
the vnode to resolve to a name.
vfs:namecache:fullpath:hit - vn_fullpath1() successfully resolved a
search for the parent of an object using the namecache, passed the
discovered parent directory vnode pointer, name, and child vnode
pointer.
vfs:namecache:fullpath:miss - vn_fullpath1() failed to resolve a search
for the parent of an object using the namecache, passed the child
vnode pointer.
vfs:namecache:fullpath:return - vn_fullpath1() has completed, passed the
error number, and if that is zero, the vnode to resolve, and the
returned path.
vfs:namecache:lookup:hit - postive name cache entry hit, passed the
parent directory vnode pointer, name, and child vnode pointer.
vfs:namecache:lookup:hit_negative - negative name cache entry hit,
passed the parent directory vnode pointer and name.
vfs:namecache:lookup:miss - name cache miss, passed the parent directory
pointer and the full remaining component name (not terminated after the
cache miss component).
vfs:namecache:purge:done - name cache purge for a vnode, passed the vnode
pointer to purge.
vfs:namecache:purge_negative:done - name cache purge of negative entries
for children of a vnode, passed the vnode pointer to purge.
vfs:namecache:purgevfs - name cache purge for a mountpoint, passed the
mount pointer. Separate probes will also be invoked for each cache
entry zapped.
vfs:namecache:zap:done - name cache entry zapped, passed the parent
directory vnode pointer, name, and child vnode pointer.
vfs:namecache:zap_negative:done - negative name cache entry zapped,
passed the parent directory vnode pointer and name.
For any probes involving an extant name cache entry (enter, hit, zapp),
we use the nul-terminated string for the name component. For misses,
the remainder of the path, including later components, is provided as
an argument instead since there is no handy nul-terminated version of
the string around. This is arguably a bug.
MFC after: 1 month
Sponsored by: Google, Inc.
Reviewed by: jhb, kan, kib (earlier version)
vfs:namei:lookup:entry takes parent directory vnode pointer, path to
look up, and lookup flags.
vfs:namei:lookup:return takes an error value, and if successful, the
returned vnode pointer.
MFC after: 1 month
1) Move the new field (brand_note) to the end of the Brandinfo structure.
2) Add a new flag BI_BRAND_NOTE that indicates that the brand_note pointer
is valid.
3) Use the brand_note field if the flag BI_BRAND_NOTE is set and as old
modules won't have the flag set, so the new field brand_note would be
ignored.
Suggested by: jhb
Reviewed by: jhb
Approved by: kib (mentor)
MFC after: 6 days
on a generic dumper that creates an ELF core file and
uses PMAP functions to scan and iterate over memory
chunks, as well as handle memory mappings used during
dumping.
the PMAP layer can choose to return physical memory
chunks or virtual memory chunks. For minidumps, the
chunks should be virtual.
The default MMU I/F implementation for the scan_md()
method returns NULL. Thus, when a PMAP implementation
does not implement the required methods, an empty
core file is created. Here, empty means having an ELF
header only.
Obtained from: Juniper Networks
in directory vnodes. Allow namecache dotdot entry to be created pointing
from child vnode to parent vnode if no existing links in opposite
direction exist. Use direct link from parent to child for dotdot lookups
otherwise.
This restores more efficient dotdot caching in NFS filesystems which
was lost when vnodes stoppped being type stable.
Reviewed by: kib
It was derived from i386 version long ago but never resync'ed again.
Originally, i386 version compared the current time from realtime clock
with time_second (which was just `time' in the old days). When this MI
version was written, it was wrongly compared against `base' AND never
used because of a bug (typo?) in the code. This check was killed
in i386 version when home-rolled calendaric calculation was removed.
Now, we just remove the code here as well to make the code simpler.
to the devctl notification queue. Empty strings cause devctl read
call to return 0 and result in devd exiting prematurely.
The actual offender (ugen notes for root hubs) will be fixed
by separate commit.
Limit the size of malloced buffer when dumping environment
variables. [EN-09:01]
Approved by: so (cperciva)
Approved by: re (kensmith)
Security: FreeBSD-SA-09:06.ktimer
Errata: FreeBSD-EN-09:01.kenv
Badly formed ELF note may cause the caclulated pointer to the next note
to point both after the note region, that was checked in the code, but
also to point before the region, that was not checked [1]. Remember the
first note location in note0 and leap out if the note is not between
note0 and note_end.
In the similar way, badly formed note may cause infinite loop by
pointing next note into the same or previous note. Guard against this by
limiting amount of loop iterations by arbitrary choosen big number.
For clarity, check the calculated note alignment in each iteration.
Reported by: Chris Palmer <chris noncombatant org> [1]
PR: kern/132886
Reviewed and tested by: dchagin
MFC after: 3 days
B_DELWRI cleanup and vnode disassociation should happen just before to
assign the buffer to a queue.
Reported by: miwi, Volker <volker at vwsoft dot com>,
Ben Kaduk <minimarmot at gmail dot com>,
Christopher Mallon <christoph dot mallon at gmx dot de>
Tested by: lulf, miwi
This fixes osrel fetching from the FreeBSD branding note for the 64bit
platforms.
Reported by: swell.k gmail com
Reviewed by: dchagin
Tested by: dchagin, swell.k gmail com
This code is heavily inspired by Takanori Watanabe's experimental SMP patch
for i386 and large portion was shamelessly cut and pasted from Peter Wemm's
AP boot code.
the "nbufkv" sleep.
First, ffs background cg group block write requests a new buffer for
the shadow copy. When ffs_bufwrite() is called from the bufdaemon due
to buffers shortage, requesting the buffer deadlock bufdaemon.
Introduce a new flag for getnewbuf(), GB_NOWAIT_BD, to request getblk
to not block while allocating the buffer, and return failure
instead. Add a flag argument to the geteblk to allow to pass the flags
to getblk(). Do not repeat the getnewbuf() call from geteblk if buffer
allocation failed and either GB_NOWAIT_BD is specified, or geteblk()
is called from bufdaemon (or its helper, see below). In
ffs_bufwrite(), fall back to synchronous cg block write if shadow
block allocation failed.
Since r107847, buffer write assumes that vnode owning the buffer is
locked. The second problem is that buffer cache may accumulate many
buffers belonging to limited number of vnodes. With such workload,
quite often threads that own the mentioned vnodes locks are trying to
read another block from the vnodes, and, due to buffer cache
exhaustion, are asking bufdaemon for help. Bufdaemon is unable to make
any substantial progress because the vnodes are locked.
Allow the threads owning vnode locks to help the bufdaemon by doing
the flush pass over the buffer cache before getnewbuf() is going to
uninterruptible sleep. Move the flushing code from buf_daemon() to new
helper function buf_do_flush(), that is called from getnewbuf(). The
number of buffers flushed by single call to buf_do_flush() from
getnewbuf() is limited by new sysctl vfs.flushbufqtarget. Prevent
recursive calls to buf_do_flush() by marking the bufdaemon and threads
that temporarily help bufdaemon by TDP_BUFNEED flag.
In collaboration with: pho
Reviewed by: tegge (previous version)
Tested by: glebius, yandex ...
MFC after: 3 weeks
in FreeBSD 5.x to allow network device drivers to run with Giant
despite the network stack being Giant-free. This significantly
simplifies calls into ioctl() on network interfaces, especially
in the multicast code, as well as eliminates deferred invocation
of interface if_start routines.
Disable the build on device drivers still depending on
IFF_NEEDSGIANT as they no longer compile. They will be removed
in a few weeks if they haven't been made MPSAFE in that time.
Disabled drivers:
if_ar
if_axe
if_aue
if_cdce
if_cue
if_kue
if_ray
if_rue
if_rum
if_sr
if_udav
if_ural
if_zyd
Drivers that were already disabled because of tty changes:
if_ppp
if_sl
Discussed on: arch@
guarantee that all cpus have acknowledged the cleared enable int by
scheduling the resetting thread on each cpu in succession. Since all
lock profiling happens within a critical section this guarantees that
all cpus have left lock profiling before we clear the datastructures.
- Assert that the per-thread queue of locks lock profiling is aware of
is clear on thread exit. There were several cases where this was not
true that slows lock profiling and leaks information.
- Remove all objects from all lists before clearing any per-cpu
information in reset. Lock profiling objects can migrate between
per-cpu caches and previously these migrated objects could be zero'd
before they'd been removed
Discussed with: attilio
Sponsored by: Nokia
is calculated as 0 which causes errors elsewhere.
Submitted by: KOIE Hidetaka <koie@suri.co.jp>
- When sched_affinity() is called with a thread that is not curthread we
need to handle the ON_RUNQ() case by adding the thread to the correct
run queue.
Submitted by: Justin Teller <justin.teller@gmail.com>
MFC after: 1 Week
".note.ABI-tag" section.
The search order of a brand is changed, now first of all the
".note.ABI-tag" is looked through.
Move code which fetch osreldate for ELF binary to check_note() handler.
PR: 118473
Approved by: kib (mentor)
poll(), only copy out the revents field, not the whole pollfd
structure. Otherwise, if the events field is updated
concurrently by another thread, that update may be lost.
This issue apparently causes problems for the JDK on FreeBSD,
which expects the Linux behavior of not updating all fields
(somewhat oddly, Solaris does not implement the required
behavior, but presumably our adaptation of the JDK is based
on the Linux port?).
MFC after: 2 weeks
PR: kern/130924
Submitted by: Kurt Miller <kurt @ intricatesoftware.com>
Discussed with: kib
internal sysctl_sysctl_name() handler to map the MIB array to a string
name and logs this name in the trace log. This can be useful to see
exactly which sysctls a thread is invoking.
MFC after: 1 month
filesystem supports additional operations using shared vnode locks.
Currently this is used to enable shared locks for open() and close() of
read-only file descriptors.
- When an ISOPEN namei() request is performed with LOCKSHARED, use a
shared vnode lock for the leaf vnode only if the mount point has the
extended shared flag set.
- Set LOCKSHARED in vn_open_cred() for requests that specify O_RDONLY but
not O_CREAT.
- Use a shared vnode lock around VOP_CLOSE() if the file was opened with
O_RDONLY and the mountpoint has the extended shared flag set.
- Adjust md(4) to upgrade the vnode lock on the vnode it gets back from
vn_open() since it now may only have a shared vnode lock.
- Don't enable shared vnode locks on FIFO vnodes in ZFS and UFS since
FIFO's require exclusive vnode locks for their open() and close()
routines. (My recent MPSAFE patches for UDF and cd9660 already included
this change.)
- Enable extended shared operations on UFS, cd9660, and UDF.
Submitted by: ups
Reviewed by: pjd (ZFS bits)
MFC after: 1 month
needed.
- Move the release of the sysctl sx lock after the vsunlock() in
userland_sysctl() to restore the original memlock behavior of
minimizing the amount of memory wired to handle sysctl requests.
MFC after: 1 week
address space sizes to be longs instead of ints. Specifically, the follow
values are now longs: runningbufspace, bufspace, maxbufspace,
bufmallocspace, maxbufmallocspace, lobufspace, hibufspace, lorunningspace,
hirunningspace, maxswzone, maxbcache, and maxpipekva. Previously, a
relatively small number (~ 44000) of buffers set in kern.nbuf would result
in integer overflows resulting either in hangs or bogus values of
hidirtybuffers and lodirtybuffers. Now one has to overflow a long to see
such problems. There was a check for a nbuf setting that would cause
overflows in the auto-tuning of nbuf. I've changed it to always check and
cap nbuf but warn if a user-supplied tunable would cause overflow.
Note that this changes the ABI of several sysctls that are used by things
like top(1), etc., so any MFC would probably require a some gross shims
to allow for that.
MFC after: 1 month
debug.hashstat.rawnchash sysctl in particular as taking 7 milliseconds on
a 3GHz Intel Xeon (4x2) running 7.1. It accounted for almost a quarter of
the total runtime of 'sysctl -a'. It also performs lots of copyout's while
holding the namecache lock (this does not attempt to fix that).
MFC after: 2 weeks
was introduced. If you have a bus, say cardbus, that is derived from
a base-bus (say PCI), then ordinarily all PCI drivers would attach to
cardbus devices. However, there had been one exception: kldload
wouldn't work.
The problem is in devclass_add_driver. In this routine, all we did
was call to the pci device's BUS_DRIVER_ADDED routine. However, since
cardbus bus instances had a different devclass, none of them were
called.
The solution is to call all subclass devclasses, recursively down the
tree, of the class that was loaded. Since we don't have a 'children
class' pointer, we search the whole list of devclasses for a class
whose parent matches. Since just done a kldload time, this isn't as
bad as it sounds. In addition, we short-circuit the whole process by
marking those classes with subclasses with a flag. We'll likely have
to reevaluate this method the number of devclasses with subclasses
gets large.
This means we can remove the "cardbus" lines from all the PCI drivers
since we have no cardbus specific attach device attachments in the
tree.
# Also: minor tweak to an error message
query functions in the kernel, as these effectively serialize
parallel calls to the gettimeofday(2) system call, as well as
other kernel services that use timestamps.
Use the NetBSD version of the fix (kern_tc.c:1.32 by ad@) as
they have picked up our timecounter code and also ran into the
same problem.
Reported by: kris
Obtained from: NetBSD
MFC after: 3 days
locks: a global list/counter/generation counter protected by a new
mutex unp_list_lock, and a global linkage rwlock, unp_global_rwlock,
which protects the connections between UNIX domain sockets.
This eliminates conditional lock acquisition that was previously a
property of the global lock being held over sonewconn() leading to a
call to uipc_attach(), which also required the global lock, but
couldn't rely on it as other paths existed to uipc_attach() that
didn't hold it: now uipc_attach() uses only the list lock, which
follows the linkage lock in the lock order. It may also reduce
contention on the global lock for some workloads.
Add global UNIX domain socket locks to hard-coded witness lock
order.
MFC after: 1 week
Discussed with: kris
directory of a vnode to find a dirent with a matching file number. The
name from that dirent is then used to provide the component name.
Note: if the initial vnode argument is not a directory itself, then
the default VOP_VPTOCNP(9) implementation still returns ENOENT.
Reviewed by: kib
Approved by: kib
Tested by: pho
extended attribute get/set; in the case of get an uninitialized user
buffer was passed before the EA was retrieved, making it of relatively
little use; the latter was simply unused by any policies.
Obtained from: TrustedBSD Project
Sponsored by: Google, Inc.
naming by renaming certain "proc" entry points to "cred" entry points,
reflecting their manipulation of credentials. For some entry points,
the process was passed into the framework but not into policies; in
these cases, stop passing in the process since we don't need it.
mac_proc_check_setaudit -> mac_cred_check_setaudit
mac_proc_check_setaudit_addr -> mac_cred_check_setaudit_addr
mac_proc_check_setauid -> mac_cred_check_setauid
mac_proc_check_setegid -> mac_cred_check_setegid
mac_proc_check_seteuid -> mac_cred_check_seteuid
mac_proc_check_setgid -> mac_cred_check_setgid
mac_proc_check_setgroups -> mac_cred_ceck_setgroups
mac_proc_check_setregid -> mac_cred_check_setregid
mac_proc_check_setresgid -> mac_cred_check_setresgid
mac_proc_check_setresuid -> mac_cred_check_setresuid
mac_proc_check_setreuid -> mac_cred_check_setreuid
mac_proc_check_setuid -> mac_cred_check_setuid
Obtained from: TrustedBSD Project
Sponsored by: Google, Inc.
poll_no_poll().
Return a poll_no_poll() result from devfs_poll_f() when
filedescriptor does not reference the live cdev, instead of ENXIO.
Noted and tested by: hps
MFC after: 1 week
Do not overload the local variable size in kern_shmat() due to vm_size_t
change.
Fix style bug by adding explicit comparision with 0.
Discussed with: bde
MFC after: 1 week
wrapper macros that allow trace points and arguments to be declared
using a single macro rather than several. This means a lot less
repetition and vertical space for each trace point.
Use these macros when defining privilege and MAC Framework trace points.
Reviewed by: jb
MFC after: 1 week
vfsopt and the vfs_buildopts function public, and add some new fields
to struct vfsopt (pos and seen), and new functions vfs_getopt_pos and
vfs_opterror.
Further extend the interface to allow reading options from the kernel
in addition to sending them to the kernel, with vfs_setopt and related
functions.
While this allows the "name=value" option interface to be used for more
than just FS mounts (planned use is for jails), it retains the current
"vfsopt" name and <sys/mount.h> requirement.
Approved by: bz (mentor)
operation is known and to retry or fail accordingly to that
outcome. This fixes the problem with namespace traversing
programs failing with random ENOENT errors if someone just
happened to try to unmount that same filesystem at the same
time.
Reported by: dhw
Reviewed by: kib, attilio
Sponsored by: Juniper Networks, Inc.
memory from int to size_t. Implement a workaround for current ABI not
allowing to properly save size for and report more then 2Gb sized segment
of shared memory.
This makes it possible to use > 2 Gb shared memory segments on 64bit
architectures. Please note the new BUGS section in shmctl(2) and
UPDATING note for limitations of this temporal solution.
Reviewed by: csjp
Tested by: Nikolay Dzham <i levsha org ua>
MFC after: 2 weeks
It's better to just use internal language constructs, because it is
likely the compiler has a better opinion on whether to perform inlining,
which is very likely to happen to struct winsize.
Submitted by: Christoph Mallon <christoph mallon gmx de>
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.
printf() and vprintf() are exactly the same, except the way arguments
are passed. Just like we see in other pieces of code (i.e. libc's
printf()), implement printf() using vprintf().
Submitted by: Christoph Mallon <christoph mallon gmx de>
As mentioned by bz and bde, the change I made wasn't the proper way to
fix. Inspired by bde's patch, perform some small cleanups to uprintf().
Reviewed by: bz
Inside do_execve(), we have a pointer `ndp', which always points to
`&nd'. I can imagine a primitive (non-optimizing) compiler to really
reserve space for such a pointer, so just remove the variable and use
`&nd' directly.
kern_time.c:
- Unused variable `p'.
kern_thr.c:
- Variable `error' is always caught immediately, so no reason to
initialize it. There is no way that error != 0 at the end of
create_thread().
kern_sig.c:
- Unused variable `code'.
kern_synch.c:
- `rval' is always assigned in all different cases.
kern_rwlock.c:
- `v' is always overwritten with RW_UNLOCKED further on.
kern_malloc.c:
- `size' is always initialized with the proper value before being used.
kern_exit.c:
- `error' is always caught and returned immediately. abort2() never
returns a non-zero value.
kern_exec.c:
- `len' is always assigned inside the if-statement right below it.
tty_info.c:
- `td' is always overwritten by FOREACH_THREAD_IN_PROC().
Found by: LLVM's scan-build
`p' is already initialized with `td->td_proc'. Because td is always
curthread, it is safe to initialize it without any locks.
Found by: LLVM's scan-build
priv:kernel:priv_check:priv_ok fires for granted privileges
priv:kernel:priv_check:priv_errr fires for denied privileges
The first argument is the requested privilege number. The naming
convention is a little different from the OpenSolaris equivilent
because we can't have '-' in probefunc names, and our privilege
namespace is different.
MFC after: 1 week
predefined set of methods, which are set in osd_register() and called
via osd_call(). Currently, no methods are defined, though prison
objects will have some in the future.
Expand the locking from a single per-type mutex to three different kinds
of locks (four if you include the requirement that the container
(e.g. prison) be locked when getting/setting data). This clears up one
existing issue, as well as others added by the method support.
Approved by: bz (mentor)
The existing code calls kern_open() to resolve the vnode of a pathname
right after a stat(). This is not correct, because it causes random
character devices to be opened in /dev. This means ls'ing a tape
streamer will cause it to rewind, for example. Changes I have made:
- Add kern_statat_vnhook() to allow binary emulators to `post-process'
struct stat, using the proper vnode.
- Remove unneeded printf's from stat() and statfs().
- Make the Linuxolator use kern_statat_vnhook(), replacing
translate_path_major_minor_at().
- Let translate_fd_major_minor() use vp->v_rdev instead of
vp->v_un.vu_cdev.
Result:
crw-rw-rw- 1 root root 0, 14 Feb 20 13:54 /dev/ptmx
crw--w---- 1 root adm 136, 0 Feb 20 14:03 /dev/pts/0
crw--w---- 1 root adm 136, 1 Feb 20 14:02 /dev/pts/1
crw--w---- 1 ed tty 136, 2 Feb 20 14:03 /dev/pts/2
Before this commit, ptmx also had a major number of 136, because it
silently allocated and deallocated a pseudo-terminal. Device nodes that
cannot be opened now have proper major/minor-numbers.
Reviewed by: kib, netchild, rdivacky (thanks!)
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
- Don't return a negative errno when using an unknown ioctl() on a
pseudo-terminal master device. Be sure to convert ENOIOCTL to ENOTTY,
just like the TTY layer does.
- Even though we should return st_rdev of the master device node when
emulating pty(4) devices, FIODGNAME should still return the name of
the slave device. Otherwise ptsname(3) and ttyname(3) return an
invalid device name.
members for a kinfo entry on a process-wide system.
- Use the newly introduced function in order to fix cases like
KERN_PROC_PROC where aggregating stats are broken because they just
consider the first thread in the pool for each process.
(Note, additively, that KERN_PROC_PROC is rather inaccurate on
thread-wide informations like the 'state' of the process. Such
informations should maybe be invalidated and being forceably discarded
by the consumers?).
- Simplify the logic of sysctl_out_proc() and adjust the
fill_kinfo_thread() accordingly.
- Remove checks on the FIRST_THREAD_IN_PROC() being NULL but add
assertives.
This patch should fix aggregate statistics for KERN_PROC_PROC.
This is one of the reasons why top doesn't use this option and now it
can be use it safely.
ps, when launched in order to display just processes, now should report
correct cpu utilization percentages and times (as opposed by the old
code).
Reviewed by: jhb, emaste
Sponsored by: Sandvine Incorporated
If the file system backing a process' cwd is removed, and procstat -f PID
is called, then these messages would have been printed. The extra verbosity is
not required in this situation.
Requested by: kib
Approved by: kib
revealed that a process' current working directory can be VBAD if the
directory is removed. This can trigger a panic when procstat -f PID is
run.
Tested by: pho
Discovered by: phobot
Reviewed by: kib
Approved by: kib
the correct behaviour (sorting by distance from the current head position
in the scan direction) and bioq_insert_head() and bioq_insert_tail()
have a well defined (and useful) behaviour, especially when intermixed
with calls to bioq_disksort().
In particular:
- fix a bug in the existing bioq_disksort() that did not use the
current head position correctly;
- redefine semantics of bioq_insert_head() and bioq_insert_tail().
bioq_insert_tail() can now be used as a barrier
between previous and subsequent calls to bioq_disksort().
The code is heavily documented in the source code so please refer
to that for the details.
Much of this code comes from Fabio Checconi. Also thanks to Kirk
for feedback on the (re)definition of bioq_insert_tail().
NOTE: in the current tree there is only a handful of files which
intermix calls to bioq_disksort() with bioq_insert_head() and
bioq_insert_tail(). The ordering of the queue in these situation
was not specified (nor easy to figure out) before, so I doubt any
of that code could be affected by the specification of the API.
Also note that the current implementation is significantly simpler
than the previous one (also used in ata_sort_queue()).
It would be useful to reimplement ata_sort_queue() using
the same code used in bioq_disksort().
MFC after: 1 week
Just like the old TTY layer, the current MPSAFE TTY layer does not make
any attempt to serialize calls of write(). Data is copied into the
kernel in 256 (TTY_STACKBUF) byte chunks. If a write() call occurs at
the same time, the data may interleave. This is especially likely when
the TTY starts blocking, because the output queue reaches the high
watermark.
I've implemented this by adding a new flag, TTY_BUSY_OUT, which is used
to mark a TTY as having a thread stuck in write(). Because I don't want
non-blocking processes to be possibly blocked by a sleeping thread, I'm
still allowing it to bypass the protection. According to this message,
the Linux kernel returns EAGAIN in such cases, but I think that's a
little too restrictive:
http://kerneltrap.org/index.php?q=mailarchive/linux-kernel/2007/5/2/85418/thread
PR: kern/118287
from the parent to the child process if they have an operation vector
of &badfileops. This narrows a set of races involving system calls that
allocate a new file descriptor, potentially block for some extended
period, and then return the file descriptor, when invoked by a threaded
program that concurrently invokes fork(2). Similar approches are used
in both Solaris and Linux, and the wideness of this race was introduced
in FreeBSD when we moved to a more optimistic implementation of
accept(2) in order to simplify locking.
A small race necessarily remains because the fork(2) might occur after
the finit() in accept(2) but before the system call has returned, but
that appears unavoidable using current APIs. However, this race is
vastly narrower.
The fix can be validated using the newfileops_on_fork regression test.
PR: kern/130348
Reported by: Ivan Shcheklein <shcheklein at gmail dot com>
Reviewed by: jhb, kib
MFC after: 1 week
Attach call without devclass set crashes the system.
On resume AHCI driver sometimes tries to create duplicate adX device.
It is surely his own problem, but IMHO it is not a reason to crash here.
Other reasons are also possible.
result in errors for a format loading but subsequent correct recognizing
for another format.
File format loading functions should avoid printing any additional
informations but just returning appropriate (and different between each
other) error condition, characterizing different informations.
Additively, the linker should handle appropriately different format
loading errors.
While a general mechanism is desired, fix a simple and common case on
amd64: file type is not recognized for link elf and confuses the linker.
Printout an error if all the registered linker classes can't recognize
and load the module.
Reviewed by: jhb
Sponsored by: Sandvine Incorporated
- Align the fifo output in fifo_print() with other vn_printf() output.
- Remove the leading space from lockmgr_printinfo() so its output lines up
in vn_printf().
- lockmgr_printinfo() now ends with a newline, so remove an extra newline
from vn_printf().
Back in 1.1 of kern_sysctl.c the sysctl() routine wired the "old" userland
buffer for most sysctls (everything except kern.vnode.*). I think to prevent
issues with wiring too much memory it used a 'memlock' to serialize all
sysctl(2) invocations, meaning that only one user buffer could be wired at
a time. In 5.0 the 'memlock' was converted to an sx lock and renamed to
'sysctl lock'. However, it still only served the purpose of serializing
sysctls to avoid wiring too much memory and didn't actually protect the
sysctl tree as its name suggested. These changes expand the lock to actually
protect the tree.
Later on in 5.0, sysctl was changed to not wire buffers for requests by
default (sysctl_handle_opaque() will still wire buffers larger than a single
page, however). As a result, user buffers are no longer wired as often.
However, many sysctl handlers still wire user buffers, so it is still
desirable to serialize userland sysctl requests. Kernel sysctl requests
are allowed to run in parallel, however.
- Expose sysctl_lock()/sysctl_unlock() routines to exclusively lock the
sysctl tree for a few places outside of kern_sysctl.c that manipulate
the sysctl tree directly including the kernel linker and vfs_register().
- sysctl_register() and sysctl_unregister() require the caller to lock
the sysctl lock using sysctl_lock() and sysctl_unlock(). The rest of
the public sysctl API manage the locking internally.
- Add a locked variant of sysctl_remove_oid() for internal use so that
external uses of the API do not need to be aware of locking requirements.
- The kernel linker no longer needs Giant when manipulating the sysctl
tree.
- Add a missing break to the loop in vfs_register() so that we stop looking
at the sysctl MIB once we have changed it.
MFC after: 1 month
sysctls during a linker file unload. We drop the lock when doing similar
operations during a linker file load. To close races, clear the LINKED
flag before dropping the lock so that the linker file is no longer visible
to userland.
MFC after: 1 week
When we leave the console TTY constantly open, we never reset the
termios attributes. This causes output processing, echoing, etc. not to
be reset to the proper values when going into single user mode after the
system has booted. It also causes nl-to-crnl-conversion not to take
place during shutdown, which causes a `staircase effect'.
This patch adds a new TTY flag, TF_OPENED_CONS, which is set when the
TTY is opened through /dev/console. Because the flags are only used by
the kernel and the pstat(8) utility, I've decided to renumber the TTY
flags. This shouldn't be an issue, because the TTY layer is not yet part
of a stable release.
Reported by: Mark Atkinson <atkin901 yahoo com>
Tested by: sepotvin
jail doesn't support. This involves a new function prison_check_af,
like prison_check_ip[46] but that checks only the family.
With this change, most of the errors generated by jailed sockets
shouldn't ever occur, at least until jails are changeable.
Approved by: bz (mentor)
return zero on success and an error code otherwise. The possible errors
are EADDRNOTAVAIL if an address being checked for doesn't match the
prison, and EAFNOSUPPORT if the prison doesn't have any addresses in
that address family. For most callers of these functions, use the
returned error code instead of e.g. a hard-coded EADDRNOTAVAIL or
EINVAL.
Always include a jailed() check in these functions, where a non-jailed
cred always returns success (and makes no changes). Remove the explicit
jailed() checks that preceded many of the function calls.
Approved by: bz (mentor)
called without calling vfs_busy() first. This made umount(8) hang waiting
for mnt_lockref to become zero, which would never happen.
Reviewed by: kib
Approved by: rwatson (mentor)
Reported by: pho
Found with: stress2
Sponsored by: FreeBSD Foundation
Right now we only have a very small amount of drivers that use clists,
but we still allocate 50 cblocks as slush space, which allows drivers to
temporarily overcommit their storage. Most of the drivers don't allow
this anyway.
I've performed the following changes:
- We don't allocate any cblocks on startup.
- I've removed the DDB command, because it has nothing useful to print
now. You can obtain the amount of allocated blocks by running `vmstat
-m | grep clist'.
- I've removed cfreecount, which is now unused.
- The old code first tries to allocate using M_NOWAIT, followed by
M_WAITOK. This doesn't make any sense, so just remove this logic. It
seems the drivers allow us to sleep anyway.
We can even remove ccmax from clist_alloc_cblocks and c_cbmax from
struct clist, but this breaks binary compatibility.
This reduces the amount of allocated cblocks on my system from 54 to 4.
The TTY buffers used the standard <sys/queue.h> lists. Unfortunately
they have a big shortcoming. If you want to have a double linked list,
but no tail pointer, it's still not possible to obtain the previous
element in the list. Inside the buffers we don't need them. This is why
I switched to custom linked list macros. The macros will also keep track
of the amount of items in the list. Because it doesn't use a sentinel,
we can just initialize the queues with zero.
In its simplest form (the output queue), we will only keep two
references to blocks in the queue, namely the head of the list and the
last block in use. All free blocks are stored behind the last block in
use.
I noticed there was a very subtle bug in the previous code: in a very
uncommon corner case, it would uma_zfree() a block in the queue before
calling memcpy() to extract the data from the block.
After running a `make buildkernel', I noticed most of the Giant locks in
sysctl are only caused by a very small amount of sysctl's:
- sysctl.name2oid. This one is locked by SYSCTL_LOCK, just like
sysctl.oidfmt.
- kern.ident, kern.osrelease, kern.version, etc. These are just constant
strings.
- kern.arandom, used by the stack protector. It is already protected by
arc4_mtx.
I also saw the following sysctl's show up. Not as often as the ones
above, but still quite often:
- security.jail.jailed. Also mark security.jail.list as MPSAFE. They
don't need locking or already use allprison_lock.
- kern.devname, used by devname(3), ttyname(3), etc.
This seems to reduce Giant locking inside sysctl by ~75% in my primitive
test setup.
mutex to a reader/writer lock. Lookup operations first grab a read lock and
perform the lookup. If the operation results in a need to modify the cache,
then it tries to do an upgrade. If that fails, it drops the read lock,
obtains a write lock, and redoes the lookup.
an interpreter definition in its program header), set the auxiliary
ELF argument AT_BASE to 0 rather than to the address that we would
have mapped the interpreter at if there had been one.
The ELF ABI specifications appear to be ambiguous as to the desired
behavior in this situation, as they define AT_BASE as the base address
of the interpreter, but do not mention what to do if there is none.
On Solaris, AT_BASE will be set to the base address of the static
binary if there is no interpreter, and on Linux, AT_BASE is set to 0.
We go with the Linux semantics as they are of more immediate utility
and allow the early runtime environment to know that the kernel has
not mapped an interpreter, but because AT_PHDR points at the ELF
header for the running binary, it is still possible to retrieve all
required mapping information when the process starts should it be
required. Either approach would be preferable to our current behavior
of passing a pointer to an unmapped region of user memory as AT_BASE.
MFC after: 3 weeks
backend kegs so it may source compatible memory from multiple backends.
This is useful for cases such as NUMA or different layouts for the same
memory type.
- Provide a new api for adding new backend kegs to secondary zones.
- Provide a new flag for adjusting the layout of zones to stagger
allocations better across cache lines.
Sponsored by: Nokia
sizeof("MAXCPU") being used to calculate a string length rather than
something more reasonable such as sizeof("32"). This shouldn't have
caused any ill effect until we run on machines with 1000000 or more
cpus.
- Restructure selscan() and selrescan() to avoid producing extra selfps
when we have a fd in multiple sets. As described below multiple selfps
may still exist for other reasons.
- Make selrescan() tolerate multiple selfds for a given descriptor
set since sockets use two selinfos per fd. If an event on each selinfo
fires selrescan() will see the descriptor twice. This could result in
select() returning 2x the number of fds actually existing in fd sets.
Reported by: mgleason@ncftp.com
pointers to the callout handler just before and just after the callout
it invoked. I attempted to do this in a manner congruent to tracing in
Solaris's callout mechanism, but couldn't quite use the same names due
to convention and syntax differences.
Example DTrace script to generate a distribution graph of callout
execution times:
callout_execute:::callout_start
{
self->cstart = timestamp;
}
callout_execute:::callout_end
{
@length = quantize(timestamp - self->cstart);
}
Reviewed by: jb
MFC after: 3 days
inside the SYSCTL() macros and thus does not need to be done for
all of the nodes scattered across the source tree.
- Mark the name-cache related sysctl's (including debug.hashstat.*) MPSAFE.
- Mark vm.loadavg MPSAFE.
- Remove GIANT_REQUIRED from vmtotal() (everything in this routine already
has sufficient locking) and mark vm.vmtotal MPSAFE.
- Mark the vm.stats.(sys|vm).* sysctls MPSAFE.
around calls to vlrureclaim() on non-MPSAFE filesystems. Specifically,
vnlru no longer needs Giant for the common case of waking up and deciding
there is nothing for it to do.
MFC after: 2 weeks
the helper function. It is supposed to be useful for any filesystem
that has to unlock dvp to walk to the ".." entry in lookup routine.
Requested by: jhb
Tested by: pho
MFC after: 1 month
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
section of code, this uses WITNESS_NORELEASE() and WITNESS_RELEASEOK() to mark
the boundaries. Both functions require the lock to be held when calling.
This is intended for scenarios like a bus asserting that the bus lock is not
dropped during a driver call. There doesn't appear to be a man page to
document this in.
Reviewed by: jhb
vnode, from -1 down. When vinvalbuf(vp, V_ALT) is done for the vnode, it
incorrectly does vm_object_page_remove(0, 0), removing all pages from
the underlying vm object, not only the pages that back the extended
attributes data.
Change vinvalbuf() to not remove any pages from the object when
V_NORMAL or V_ALT are specified. Instead, the only in-tree caller
in ffs_inode.c:ffs_truncate() that specifies V_ALT explicitely
removes the corresponding page range. The V_NORMAL caller
does vnode_pager_setsize(vp, 0) immediately after the call to
vinvalbuf(V_NORMAL) already.
Reported by: csjp
Reviewed by: ups
MFC after: 3 weeks
In normal operation, the number of cache entries is roughly equal to the
number of active vnodes. However, when most of the recently accessed
vnodes have many hard links, the number of cache entries can be 32000
times as large, exhausting kernel memory and provoking a panic in
kmem_malloc().
MFC after: 2 weeks
with src/tools/sched/schedgraph.py. This allows developers to quickly
create a graphical view of ktr data for any resource in the system.
- Add sched_tdname() and the pcpu field 'name' for quickly and uniformly
identifying records associated with a thread or cpu.
- Reimplement the KTR_SCHED traces using the new generic facility.
Obtained from: attilio
Discussed with: jhb
Sponsored by: Nokia
guarantee atomicity of the operation for other semaphore consumers.
In particular, this should guard against access to the semaphore with
not done or partially done MAC label assignment.
Reviewed by: rwatson
MFC after: 1 month
on SysV semaphores.
The squeeze of the semaphore array in the kern_semctl() modifies
sem_base for the semaphores with sem_base greater then sem_base of
the removed semaphore, as well as the values of the semaphores,
without locking their mutex. This can lead to (killable) hangs or
unexpected behaviour of the processes performing any sem operations
while other process does IPC_RMID.
The semexit_myhook() eventhandler unlocks SEMUNDO_LOCK() while
accessing *suptr. This allows for IPC_RMID for the sem id to be
performed in parallel with undo hook referenced by the current undo
structure. This leads to the panic("semexit - semid not allocated") [1].
The semaphore creation is protected by Giant, while IPC_RMID is done
while only semaphore mutex is held. This seems to result in invalid
values for semtot, causing random ENOSPC error returns [2].
Redo the locking of the semaphores lifetime cycle. Delegate the
sem_mtx to the sole purpose of protecting semget() and
semctl(IPC_RMID). Introduce new sem_undo_mtx to protect SEM_UNDO
handling. Remove the Giant remnants from the code.
Note that mac_sysvsem_check_semget() and mac_sysvsem_create() are
now called while sem_mtx is held, as well as mac_sysvsem_cleanup() [3].
When semaphore is removed, acquire semaphore locks for all semaphores
with sem_base that is going to be changed by squeeze of the sema
array. The lock order is not important there, because the region is
protected by sem_mtx.
Organize both used and free sem_undo structures into the lists,
protected by sem_undo_mtx. In semexit_myhook(), remove sem_undo
structure that is being processed, from used list, without putting it
onto the free to prevent modifications by other threads. This allows
for sem_undo_lock to be dropped to acquire individial semaphore locks
without violating lock order. Since IPC_RMID may no longer find this
sem_undo, do tolerate references to unallocated semaphores in undo
structure, and check sequential number to not undo unrelated semaphore
with the same id.
While there, convert functions definitions to ANSI C and fix small
style(9) glitches.
Reported by: Omer Faruk Sen <omerfsen gmail com> [1], pho [2]
Reviewed by: rwatson [3]
Tested by: pho
MFC after: 1 month
locked. Lookup could attempt to recursively lock that vnode.
Do not call vn_start_write(V_WAIT) while vnode is locked, this may
result in a deadlock with suspension.
vfs_busy() the mountpoint before dropping vnode lock for vnode
that was used to look up the mountpoint, to prevent unmount in
between.
Reported and tested by: pho
Reviewed by: rwatson
MFC after: 3 weeks
During boot, the domain list is locked with Giant. It is not possible to
register any protocols after the system has booted, so the lock is only
used to protect insertion of entries.
There is already a mutex in uipc_domain.c called dom_mtx. Use this mutex
to lock the list, instead of using Giant. It won't matter anything with
respect to performance, but we'll never get rid of Giant if we don't
remove from places where we don't need it.
Approved by: rwatson
MFC after: 3 weeks
of the counter, that may happen when too many sendfile(2) calls are
being executed with this vnode [1].
To keep the size of the struct vm_page and offsets of the fields
accessed by out-of-tree modules, swap the types and locations
of the wire_count and cow fields. Add safety checks to detect cow
overflow and force fallback to the normal copy code for zero-copy
sockets. [2]
Reported by: Anton Yuzhaninov <citrin citrin ru> [1]
Suggested by: alc [2]
Reviewed by: alc
MFC after: 2 weeks
During startup some of the syscons TTY's are used to set attributes like
the screensaver and mouse options. These actions cause /dev/console to
be rendered unusable.
Fix the issue by leaving the TTY opened when it is used as the console
device.
Reported by: imp
the field in the mbuf constructors, since otherwise we have no way to
tell if they are valid. In the future, Kip has plans to add a flag
specifically to indicate validity, which is the preferred model.
When sysctl() is being called with a buffer that is too small, it will
return ENOMEM. Unfortunately the changes I made the other day sets the
error number to 0, because it just returns the error number of the
copyout(). Revert this part of the change.
did not compared nc_dvp with supplied parent directory vnode pointer.
Add the check and note that now branches for vp != NULL and vp == NULL
are the same, thus can be merged.
Reported and reviewed by: kan
Tested by: pho
MFC after: 2 weeks
It seems I forgot to remove `int error' from a single piece of code. I'm
also moving ogetkerninfo() to kern_xxx.c, because it belongs to the
class of compat system information system calls, not the generic sysctl
code.
In the existing code we didn't really enforce that callers hold Giant
before calling userland_sysctl(), even though there is no guarantee it
is safe. Fix this by just placing Giant locks around the call to the oid
handler. This also means we only pick up Giant for a very short period
of time. Maybe we should add MPSAFE flags to sysctl or phase it out all
together.
I've also added SYSCTL_LOCK_ASSERT(). We have to make sure sysctl_root()
and name2oid() are called with the sysctl lock held.
Reviewed by: Jille Timmermans <jille quis cx>
compare map->timestamp with saved timestamp after map read lock is
reacquired, not with saved timestamp + 1. The only consequence of the +1
was unconditional lookup of the next map entry, though.
Tested by: pho
Approved by: des
MFC after: 2 weeks
arrays under #ifndef XEN to make XEN config compile again.
In case of Xen vm_guest is hard coded.
Move the list for the vm_guest sysctl out of the restictive
bounds as the sysctl is there in either case.
