In particular, do not lock Giant conditionally when calling into the
filesystem module, remove the VFS_LOCK_GIANT() and related
macros. Stop handling buffers belonging to non-mpsafe filesystems.
The VFS_VERSION is bumped to indicate the interface change which does
not result in the interface signatures changes.
Conducted and reviewed by: attilio
Tested by: pho
filters (ipfw and PF) use the same ruleset with the same lock for both
AF_INET and AF_INET6 there is no need in more fine-grade locking.
However, it is possible to request personal lock by specifying
PFIL_FLAG_PRIVATE_LOCK flag in pfil_head structure (see pfil.9 for
more details).
Export PFIL lock via rw_lock(9)/rm_lock(9)-like API permitting pfil consumers
to use this lock instead of own lock. This help reducing locks on main
traffic path.
pfil_assert() is currently not implemented due to absense of rm_assert().
Waiting for some kind of r234648 to be merged in HEAD.
This change is part of bigger patch reducing routing locking.
Sponsored by: Yandex LLC
Reviewed by: glebius, ae
OK'd by: silence on net@
MFC after: 3 weeks
- All packets in NETISR_IP queue are in net byte order.
- ip_input() is entered in net byte order and converts packet
to host byte order right _after_ processing pfil(9) hooks.
- ip_output() is entered in host byte order and converts packet
to net byte order right _before_ processing pfil(9) hooks.
- ip_fragment() accepts and emits packet in net byte order.
- ip_forward(), ip_mloopback() use host byte order (untouched actually).
- ip_fastforward() no longer modifies packet at all (except ip_ttl).
- Swapping of byte order there and back removed from the following modules:
pf(4), ipfw(4), enc(4), if_bridge(4).
- Swapping of byte order added to ipfilter(4), based on __FreeBSD_version
- __FreeBSD_version bumped.
- pfil(9) manual page updated.
Reviewed by: ray, luigi, eri, melifaro
Tested by: glebius (LE), ray (BE)
tree used it incorrectly, which lead to inaccurate overrated
if_obytes accounting. The drbr(9) used to update ifnet stats on
drbr_enqueue(), which is not accurate since enqueuing doesn't
imply successful processing by driver. Dequeuing neither mean
that. Most drivers also called drbr_stats_update() which did
accounting again, leading to doubled if_obytes statistics. And
in case of severe transmitting, when a packet could be several
times enqueued and dequeued it could have been accounted several
times.
o Thus, make drbr(9) API thinner. Now drbr(9) merely chooses between
ALTQ queueing or buf_ring(9) queueing.
- It doesn't touch the buf_ring stats any more.
- It doesn't touch ifnet stats anymore.
- drbr_stats_update() no longer exists.
o buf_ring(9) handles its stats itself:
- It handles br_drops itself.
- br_prod_bytes stats are dropped. Rationale: no one ever
reads them but update of a common counter on every packet
negatively affects performance due to excessive cache
invalidation.
- buf_ring_enqueue_bytes() reduced to buf_ring_enqueue(), since
we no longer account bytes.
o Drivers handle their stats theirselves: if_obytes, if_omcasts.
o mlx4(4), igb(4), em(4), vxge(4), oce(4) and ixv(4) no longer
use drbr_stats_update(), and update ifnet stats theirselves.
o bxe(4) was the most correct driver, it didn't call
drbr_stats_update(), thus it was the only driver accurate under
moderate load. Now it also maintains stats itself.
o ixgbe(4) had already taken stats from hardware, so just
- drop software stats updating.
- take multicast packet count from hardware as well.
o mxge(4) just no longer needs NO_SLOW_STATS define.
o cxgb(4), cxgbe(4) need no change, since they obtain stats
from hardware.
Reviewed by: jfv, gnn
- Provide missing function that can do hashing of arbitrary sized buffer.
- Refetch lookup3.c and do only minimal edits to it, so that diff between
our jenkins_hash.c and lookup3.c is minimal.
- Add declarations for jenkins_hash(), jenkins_hash32() to sys/hash.h.
- Document these functions in hash(9)
Obtained from: http://burtleburtle.net/bob/c/lookup3.c
1) It is not useful to call "devfs_clear_cdevpriv()" from
"d_close" callbacks, hence for example read, write, ioctl and
so on might be sleeping at the time of "d_close" being called
and then then freed private data can still be accessed.
Examples: dtrace, linux_compat, ksyms (all fixed by this patch)
2) In sys/dev/drm* there are some cases in which memory will
be freed twice, if open fails, first by code in the open
routine, secondly by the cdevpriv destructor. Move registration
of the cdevpriv to the end of the drm open routines.
3) devfs_clear_cdevpriv() is not called if the "d_open" callback
registered cdevpriv data and the "d_open" callback function
returned an error. Fix this.
Discussed with: phk
MFC after: 2 weeks
a da(4) instance going away while GEOM is still probing it.
In this case, the GEOM disk class instance has been created by
disk_create(), and the taste of the disk is queued in the GEOM
event queue.
While that event is queued, the da(4) instance goes away. When the
open call comes into the da(4) driver, it dereferences the freed
(but non-NULL) peripheral pointer provided by GEOM, which results
in a panic.
The solution is to add a callback to the GEOM disk code that is
called when all of its resources are cleaned up. This is
implemented inside GEOM by adding an optional callback that is
called when all consumers have detached from a provider, and the
provider is about to be deleted.
scsi_cd.c,
scsi_da.c: In the register routine for the cd(4) and da(4)
routines, acquire a reference to the CAM peripheral
instance just before we call disk_create().
Use the new GEOM disk d_gone() callback to register
a callback (dadiskgonecb()/cddiskgonecb()) that
decrements the peripheral reference count once GEOM
has finished cleaning up its resources.
In the cd(4) driver, clean up open and close
behavior slightly. GEOM makes sure we only get one
open() and one close call, so there is no need to
set an open flag and decrement the reference count
if we are not the first open.
In the cd(4) driver, use cam_periph_release_locked()
in a couple of error scenarios to avoid extra mutex
calls.
geom.h: Add a new, optional, providergone callback that
is called when a provider is about to be deleted.
geom_disk.h: Add a new d_gone() callback to the GEOM disk
interface.
Bump the DISK_VERSION to version 2. This probably
should have been done after a couple of previous
changes, especially the addition of the d_getattr()
callback.
geom_disk.c: Add a providergone callback for the disk class,
g_disk_providergone(), that calls the user's
d_gone() callback if it exists.
Bump the DISK_VERSION to 2.
geom_subr.c: In g_destroy_provider(), call the providergone
callback if it has been provided.
In g_new_geomf(), propagate the class's
providergone callback to the new geom instance.
blkfront.c: Callers of disk_create() are supposed to pass in
DISK_VERSION, not an explicit disk API version
number. Update the blkfront driver to do that.
disk.9: Update the disk(9) man page to include information
on the new d_gone() callback, as well as the
previously added d_getattr() callback, d_descr
field, and HBA PCI ID fields.
MFC after: 5 days
- Consistently refer to rmlocks as "read-mostly locks".
- Relate rmlocks to rwlocks rather than sx locks since they are closer to
rwlocks.
- Add a separate paragraph on sleepable read-mostly locks contrasting them
with "normal" read-mostly locks.
- The flag passed to rm_init_flags() to enable recursion for readers is
RM_RECURSE, not LO_RECURSABLE.
- Fix the description for RM_RECURSE (it allows readers to recurse, not
writers).
- Explicitly note that rm_try_rlock() honors RM_RECURSE.
- Fix some minor grammar nits.
Fix panic on tcpdump being attached to interface being removed (introduced by r233937, pointed by hrs@ and adrian@)
Protect most of bpf_setf() by BPF global lock
Add several forgotten assertions (thanks to adrian@)
Document current locking model inside bpf.c
Document EVENTHANDLER(9) usage inside BPF.
Approved by: kib(mentor)
Tested by: gnn
MFC in: 4 weeks
Function acquired reader lock if needed.
Assert check for reader or writer lock (RA_LOCKED / RA_UNLOCKED)
- While here, add knlist_init_mtx.9 to MLINKS and fix some style(9) issues
Reviewed by: glebius
Approved by: ae(mentor)
MFC after: 2 weeks
3rd argument of ifa->ifa_rtrequest is now ``rt_addrinfo *'' instead of
``sockaddr *''. While here, un-document RTM_RESOLVE cmd argument for
ifa_rtrequest() that became a stub after separating L2 tables in r186119.
MFC after: 1 week
- Document the following routines: pci_alloc_msi(), pci_alloc_msix(),
pci_find_cap(), pci_get_max_read_req(), pci_get_vpd_ident(),
pci_get_vpd_readonly(), pci_msi_count(), pci_msix_count(),
pci_pending_msix(), pci_release_msi(), pci_remap_msix(), and
pci_set_max_read_req().
- Group the functions into five sub-sections: raw configuration access,
locating devices, device information, device configuration, and
message signaled interrupts.
- Discourage use of pci_disable_io() and pci_enable_io() in device drivers.
The PCI bus driver handles this automatically as resources are activated.
MFC after: 2 weeks
not ACPI-specific at all, but deal with PCI power states. Also,
pci_set_powerstate() fails with EOPNOTSUPP if a request is made that the
underlying device does not support rather than falling back to somehow
setting D0.
pci_cfg_save() and pci_cfg_restore() for device drivers to use when
saving and restoring state (e.g. to handle device-specific resets).
Reviewed by: imp
MFC after: 2 weeks
The reasoning behind this, is that if we are consistent in our
documentation about the uint*_t stuff, people will be less tempted to
write new code that uses the non-standard types.
I am not going to bump the man page dates, as these changes can be
considered style nits. The meaning of the man pages is unaffected.
MFC after: 1 month
These functions take a `struct cdev *' -- not a dev_t. Inside the
kernel, dev_t has the same use as in userspace, namely to store a device
identifier.
MFC after: 2 weeks
I was considering adding it to libc as well, but last minute I thought
it would be good enough to add it to libkern exclusively. I forgot to
rename the man page and hook it up.
It seems two of the file system drivers we have in the tree, namely ufs
and ext3, use a function called `skpc()'. The meaning of this function
does not seem to be documented in FreeBSD, but it turns out one needs to
be a VAX programmer to understand what it does.
SPKC is an instruction on the VAX that does the opposite of memchr(). It
searches for the non-equal character. Add a new function called
memcchr() to the tree that has the following advantages over skpc():
- It has a name that makes more sense than skpc(). Just like strcspn()
matches the complement of strspn(), memcchr() is the complement of
memchr().
- It is faster than skpc(). Similar to our strlen() in libc, it compares
entire words, instead of single bytes. It seems that for this routine
this yields a sixfold performance increase on amd64.
- It has a man page.
objects created by shm_open(2) into the kernel's address space. This
provides a convenient way for creating shared memory buffers between
userland and the kernel without requiring custom character devices.
and DEVMETHOD() we can fully hide the explicit mention of kobj(9) from
device drivers.
- Update the example in driver.9 to use DEVMETHOD_END.
Submitted by: jhb
MFC after: 3 days
This enables locking consumers to pass their own structures around as const and
be able to assert locks embedded into those structures.
Reviewed by: ed, kib, jhb
curthread-accessing part of mtx_{,un}lock(9) when using a r210623-style
curthread implementation on sparc64, crashing the kernel in its early
cycles as PCPU isn't set up, yet (and can't be set up as OFW is one of the
things we need for that, which leads to a chicken-and-egg problem). What
happens is that due to the fact that the idea of r210623 actually is to
allow the compiler to cache invocations of curthread, it factors out
obtaining curthread needed for both mtx_lock(9) and mtx_unlock(9) to
before the branch based on kobj_mutex_inited when compiling the kernel
without the debugging options. So change kobj_class_compile_static(9)
to just never acquire kobj_mtx, effectively restricting it to its
documented use, and add a kobj_init_static(9) for initializing objects
using a class compiled with the former and that also avoids using mutex(9)
(and malloc(9)). Also assert in both of these functions that they are
used in their intended way only.
While at it, inline kobj_register_method() and kobj_unregister_method()
as there wasn't much point for factoring them out in the first place
and so that a reader of the code has to figure out the locking for
fewer functions missing a KOBJ_ASSERT.
Tested on powerpc{,64} by andreast.
Reviewed by: nwhitehorn (earlier version), jhb
MFC after: 3 days
document knlist_delete, and better document what knlist_clear does... Note
that both of these functions may sleep, and also unlock/relock the list
lock...
document knlist_init_mtx (forgotten by kib)...
other minor improvements
Reviewed by: ru (previous rev)
MFC after: 1 week
mod_cc.4 and mod_cc.9 respectively to avoid any possible confusion with the cc.1
gcc man page. Update references to these man pages where required.
Requested by: Grenville Armitage
Approved by: re (kib)
MFC after: 3 days
If it overflows before the taskqueue can run, the task will be
re-added to the taskqueue and cause a loop in the task list.
Reported by: Arnaud Lacombe <lacombar@gmail.com>
Submitted by: Ryan Stone <rysto32@gmail.com>
Reviewed by: jhb
Approved by: re (kib)
MFC after: 1 day
If a selinfo object is recorded (via selrecord()) and then it is
quickly destroyed, with the waiters missing the opportunity to awake,
at the next iteration they will find the selinfo object destroyed,
causing a PF#.
That happens because the selinfo interface has no way to drain the
waiters before to destroy the registered selinfo object. Also this
race is quite rare to get in practice, because it would require a
selrecord(), a poll request by another thread and a quick destruction
of the selrecord()'ed selinfo object.
Fix this by adding the seldrain() routine which should be called
before to destroy the selinfo objects (in order to avoid such case),
and fix the present cases where it might have already been called.
Sometimes, the context is safe enough to prevent this type of race,
like it happens in device drivers which installs selinfo objects on
poll callbacks. There, the destruction of the selinfo object happens
at driver detach time, when all the filedescriptors should be already
closed, thus there cannot be a race.
For this case, mfi(4) device driver can be set as an example, as it
implements a full correct logic for preventing this from happening.
Sponsored by: Sandvine Incorporated
Reported by: rstone
Tested by: pluknet
Reviewed by: jhb, kib
Approved by: re (bz)
MFC after: 3 weeks
to be assigned to a non-default FIB instance.
You may need to recompile world or ports due to the change of struct ifnet.
Submitted by: cjsp
Submitted by: Alexander V. Chernikov (melifaro ipfw.ru)
(original versions)
Reviewed by: julian
Reviewed by: Alexander V. Chernikov (melifaro ipfw.ru)
MFC after: 2 weeks
X-MFC: use spare in struct ifnet
wrapper around rman_adjust_resource(). Include a generic implementation,
bus_generic_adjust_resource() which passes the request up to the parent
bus. There is currently no default implementation. A
bus_adjust_resource() wrapper is provided for use in drivers.
Specifically, these changes allow a resource to back a relocatable and
resizable resource such as the I/O window decoders in PCI-PCI bridges.
- rman_adjust_resource() can adjust the start and end address of an
existing resource. It only succeeds if the newly requested address
space is already free. It also supports shrinking a resource in
which case the freed space will be marked unallocated in the rman.
- rman_first_free_region() and rman_last_free_region() return the
start and end addresses for the first or last unallocated region in
an rman, respectively. This can be used to determine by how much
the resource backing an rman must be adjusted to accomodate an
allocation request that does not fit into the existing rman.
While here, document the rm_start and rm_end fields in struct rman,
rman_is_region_manager(), the bound argument to
rman_reserve_resource_bound(), and rman_init_from_resource().
While there, fix the type of the func argument of INIT_TASK macro,
and use the modern name of the analogous facility from Linux kernel.
Sponsored by: The FreeBSD Foundation
MFC after: 1 month
FreeBSD" FreeBSD Foundation funded project.
- Add new man pages for the modular congestion control, Khelp and Hhook
frameworks (cc.4, cc.9, khelp.9 and hhook.9).
- Add new man pages for each available congestion control algorithm (cc_chd.4,
cc_cubic.4, cc_hd.4, cc_htcp.4, cc_newreno.4 and cc_vegas.4).
- Add a new man page for the Enhanced Round Trip Time (ERTT) Khelp module
(h_ertt.4).
- Update the TCP (tcp.4) man page to mention the TCP_CONGESTION socket option,
cross reference to cc.4 and remove references to the retired
"net.inet.tcp.newreno" sysctl MIB variable.
In collaboration with: David Hayes <dahayes at swin edu au> and
Grenville Armitage <garmitage at swin edu au>
Sponsored by: FreeBSD Foundation
MFC after: 3 months
sbuf_new_for_sysctl(9). This allows using an sbuf with a SYSCTL_OUT
drain for extremely large amounts of data where the caller knows that
appropriate references are held, and sleeping is not an issue.
Inspired by: rwatson
may still return a non-zero value... You are not guaranteed to get a one
to one mapping between wakeup_one and zero return values...
Reviewed by: kib
MFC after: 3 days
reading. (This was already done for writing to a sysctl). This
requires all SYSCTL setups to specify a type. Most of them are now
checked at compile-time.
Remove SYSCTL_*X* sysctl additions as the print being in hex should be
controlled by the -x flag to sysctl(8).
Succested by: bde
Although not directly related the FreeBSD Foundation funded "Five New TCP
Congestion Control Algorithms for FreeBSD" project, the understanding and
inspiration required to write this documentation was significantly bolstered
by the Foundation's support.
Reviewed by: pjd
MFC after: 1 week
Passing a count of zero on i386 and amd64 for [I386|AMD64]_BUS_SPACE_MEM
causes a crash/hang since the 'loop' instruction decrements the counter
before checking if it's zero.
PR: kern/80980
Discussed with: jhb
only happen if VOP_INACTIVATE() drops the vnode lock, which is quite
unreasonable behaviour for filesystem, and should not be mentioned
in the description of VFS primitives.
MFC after: 1 week
svn r147332 (by jeff): "Don't make vgonel() globally visible".
While here, specify the vnode locking scheme for vgone().
Discussed on: freebsd-hackers@
Approved by: kib (mentor)
MFC after: 10 days
It's a bit more pedantic regarding .Bl list elements. This has an added
benefit of unbreaking the ipfw(8) manpage, where groff was silently
skipping one list element.
rounding. The same value can also be obtained with uma_zone_get_max, but this
change avoids a caller having to make two back-to-back calls.
Sponsored by: FreeBSD Foundation
Reviewed by: gnn, jhb
- Add uma_zone_get_cur which returns the current approximate occupancy of
a zone. This is useful for providing stats via sysctl amongst other things.
Sponsored by: FreeBSD Foundation
Reviewed by: gnn, jhb
MFC after: 2 weeks
A new function prep_devname() sanitizes a device name by removing
leading and redundant sequential slashes. The function returns an error
for names which already exist or are considered invalid.
A new flag MAKEDEV_CHECKNAME for make_dev_p(9) and make_dev_credf(9)
indicates that the caller is prepared to handle an error related to the
device name. An invalid name triggers a panic if the flag is not
specified.
Document the MAKEDEV_CHECKNAME flag in the make_dev(9) manual page.
Idea from: kib
Reviewed by: kib
code associated with overflow or with the drain function. While this
function is not expected to be used often, it produces more information
in the form of an errno that sbuf_overflowed() did.
called when the sbuf internal buffer is filled. For kernel sbufs with a
drain, the internal buffer will never be expanded. For userland sbufs
with a drain, the internal buffer may still be expanded by
sbuf_[v]printf(3).
Sbufs now have three basic uses:
1) static string manipulation. Overflow is marked.
2) dynamic string manipulation. Overflow triggers string growth.
3) drained string manipulation. Overflow triggers draining.
In all cases the manipulation is 'safe' in that overflow is detected and
managed.
Reviewed by: phk (the previous version)
- add rm_try_rlock().
- add RM_SLEEPABLE to use sx(9) as the back-end lock in order to sleep while
holding the write lock.
- change rm_noreadtoken to a cpu bitmask to indicate which CPUs need to go
through the lock/unlock in order to synchronize. As a side effect, this
also avoids IPI to CPUs without any readers during rm_wlock.
Discussed with: ups@, rwatson@ on arch@
Sponsored by: Isilon Systems, Inc.
- chooseproc() is long gone, MLINK choosethread instead
- Update NAME section for choosethread
- Mark chooseproc.9 for removal
PR: 149549
Submitted by: pluknet
MFC after: 1 week
use-after-free over a longer time. Also release the backing pages of
a guarded allocation at free(9) time to reduce the overhead of using
memguard(9). Allow setting and varying the malloc type at run-time.
Add knobs to allow:
- randomly guarding memory
- adding un-backed KVA guard pages to detect underflow and overflow
- a lower limit on the size of allocations that are guarded
Reviewed by: alc
Reviewed by: brueffer, Ulrich Spörlein <uqs spoerlein net> (man page)
Silence from: -arch
Approved by: zml (mentor)
MFC after: 1 month
taskqueues, more than one task can be running simultaneously.
Also make taskqueue_run(9) static to the file, since there are no
consumers in the base kernel and the function signature needs to change
with this fix.
Remove mention of taskqueue_run(9) and taskqueue_run_fast(9) from the
taskqueue(9) man page.
Reviewed by: jhb
Approved by: zml (mentor)
numbers. This change adds a new function alloc_unr_specific() which
returns the requested unit number if it is free. If the number is
already allocated or out of the range, -1 is returned.
Update alloc_unr(9) manual page accordingly and add a MLINK for
alloc_unr_specific(9).
Discussed on: freebsd-hackers
document one of the optional flags; clarify which of the flags are
optional (and which are not), and remove mention of a restriction on
the reclamation of cached pages that no longer holds since version 7.
MFC after: 1 week
than camelCase or TitleCase.
According to grep and my checked-out source tree, we're currently at
3733379 internal_underscores, 93024 camelCases, and 80831 TitleCases;
so this commit is merely documenting existing practice.
bottom of the manpages and order them consistently.
GNU groff doesn't care about the ordering, and doesn't even mention
CAVEATS and SECURITY CONSIDERATIONS as common sections and where to put
them.
Found by: mdocml lint run
Reviewed by: ru
things allows variable length messages to be easily supported.
- Extend KPI with alq_writen() and alq_getn() to support variable length
messages, which is enabled at ALQ creation time depending on the
arguments passed to alq_open(). Also add variants of alq_open() and
alq_post() that accept a flags argument. The KPI is still fully
backwards compatible and shouldn't require any change in ALQ consumers
unless they wish to utilise the new features.
- Introduce the ALQ_NOACTIVATE and ALQ_ORDERED flags to allow ALQ consumers
to have more control over IO scheduling and resource acquisition
respectively.
- Strengthen invariants checking.
- Document ALQ changes in ALQ(9) man page.
Sponsored by: FreeBSD Foundation
Reviewed by: gnn, jeff, rpaulo, rwatson
MFC after: 1 month
Although groff_mdoc(7) gives another impression, this is the ordering
most widely used and also required by mdocml/mandoc.
Reviewed by: ru
Approved by: philip, ed (mentors)
