We short-circuit lockmgr functions in the face of a kernel panic. Other
lock implementations do this with a SCHEDULER_STOPPED() check, which
covers the additional case where the debugger is active but the system
has not panicked. Update this code to match that behaviour.
Reviewed by: mjg, kib, markj
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D38655
If there are multiple instances of mountd(8) (in different
prisons), there will be confusion if they manipulate the
exports of the same file system. This patch adds mnt_exjail
to "struct mount" so that the credentials (and, therefore,
the prison) that did the exports for that file system can
be recorded. If another prison has already exported the
file system, vfs_export() will fail with an error.
If mnt_exjail == NULL, the file system has not been exported.
mnt_exjail is checked by the NFS server, so that exports done
from within a different prison will not be used.
The patch also implements vfs_exjail_destroy(), which is
called from prison_cleanup() to release all the mnt_exjail
credential references, so that the prison can be removed.
Mainly to avoid doing a scan of the mountlist for the case
where there were no exports done from within the prison,
a count of how many file systems have been exported from
within the prison is kept in pr_exportcnt.
Reviewed by: markj
Discussed with: jamie
Differential Revision: https://reviews.freebsd.org/D38371
MFC after: 3 months
This API change led to unexpected consequences with Go runtime. The
Go runtime emulates blocking sockets over non-blocking sockets and
for that uses available event dispatcher on the target OS, which is
kevent(2) if availabe, with OS independent layer on top. It expects
that if whatever O_NONBLOCK socket returned ever EAGAIN, then it is
supposed to be reported as writable by the event dispatcher. kevent(2)
would never report a unix/dgram socket, since they never change their
state, they always are writeable. The expectations of Go are not
literally specified by SUS, however they are in its spirit. The SUS
specifies EAGAIN for send(2) as "The socket's file descriptor is marked
O_NONBLOCK and the requested operation would block" [1]. This doesn't
apply to FreeBSD unix/dgram socket, it never blocks on send(2).
Thus, changing API trying to mimic Linux was a mistake. But what about
the problem we tried to fix? Discussed that with Max Dounin of nginx,
and we agreed that the log bomb described shall be fixed on nginx side,
and it actually isn't specific to FreeBSD, may happen with nginx on any
non-Linux system with a certain configuration.
[1] https://pubs.opengroup.org/onlinepubs/9699919799/functions/send.html
This reverts commit 65572cade3.
`prison_ip_restrict()` is called in loop FOREACH_PRISON_DESCENDANT_LOCKED.
While under low memory, it is still possible that in subsequent rounds
`prison_ip_restrict()` succeed and `redo_ip[46]` flip over from true to
false, thus leave some prisons's IPv[46] addresses unrestricted.
Reviewed by: jamie
Fixes: 8bce8d28ab jail: Avoid multipurpose return value of function prison_ip_restrict()
Differential Revision: https://reviews.freebsd.org/D38697
The interrupt counts may have been valuable in the past, but now DDB can
readily provide them via 'show intrcnt'. This is one of the only
consumers of these counter arrays outside of the interrupt code itself,
and this should be avoided.
Reviewed by: mhorne, fuz
Differential Revision: https://reviews.freebsd.org/D37870
- Use atomic_store to set job->error. atomic_set does an or
operation, not assignment.
- Use refcount_* to manage job->nbio.
This ensures proper memory barriers are present so that the last bio
won't see a possibly stale value of job->error.
- Don't re-read job->error after reading it via atomic_load.
Reported by: markj (1)
Reviewed by: mjg, markj
Differential Revision: https://reviews.freebsd.org/D38611
Use atomic_fetchadd in place of separate atomic_subtract / atomic_load.
Reviewed by: markj
Sponsored by: HPE TidalScale
Differential Revision: https://reviews.freebsd.org/D38559
Crucially, this allows releasing counters, and interrupt sources by
extension. Where before we were incrementing intrcnt_index with atomics,
now we protect the bitmap using the existing isrc_table_lock mutex.
Reviewed by: mmel
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D38437
soconnectat() tries to ensure that one cannot connect a connected
socket. However, the check is racy and does not really prevent two
threads from attempting to connect the same TCP socket.
Modify tcp_connect() and tcp6_connect() to perform the check again, this
time synchronized by the inpcb lock, under which we call
soisconnecting().
Reported by: syzkaller
Reviewed by: glebius
MFC after: 2 weeks
Sponsored by: Klara, Inc.
Sponsored by: Modirum MDPay
Differential Revision: https://reviews.freebsd.org/D38507
Also do minor style adjustments.
Reviewed by: markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D38549
For sched_relinquish(). This fixes the build for some kernel configs.
Reported by: Jenkins
Fixes: 1029dab634 ("mi_switch(): clean up switch types and their usage")
Address some last minute review feedback on c0e4090e3d
by fixing spacing around comments, and clarifying that the
newly added destroy_task is not related to tls 1.0.
No functional change intended.
Pointed out by: jhb
Sponsored by: Netflix
This allows us to avoid spurious calls to ktls_disable_ifnet()
When we implemented ifnet kTLSe, we set a flag in the tx socket
buffer (SB_TLS_IFNET) to indicate ifnet kTLS. This flag meant that
now, or in the past, ifnet ktls was active on a socket. Later,
I added code to switch ifnet ktls sessions to software in the case
of lossy TCP connections that have a high retransmit rate.
Because TCP was using SB_TLS_IFNET to know if it needed to do math
to calculate the retransmit ratio and potentially call into
ktls_disable_ifnet(), it was doing unneeded work long after
a session was moved to software.
This patch carefully tracks whether or not ifnet ktls is still enabled
on a TCP connection. Because the inp is now embedded in the tcpcb, and
because TCP is the most frequent accessor of this state, it made sense to
move this from the socket buffer flags to the tcpcb. Because we now need
reliable access to the tcbcb, we take a ref on the inp when creating a tx
ktls session.
While here, I noticed that rack/bbr were incorrectly implementing
tfb_hwtls_change(), and applying the change to all pending sends,
when it should apply only to future sends.
This change reduces spurious calls to ktls_disable_ifnet() by 95% or so
in a Netflix CDN environment.
Reviewed by: markj, rrs
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D38380
Overall, this is a non-functional change, except for kernels built with
SCHED_STATS. However, the switch types are useful for communicating the
intent of the caller.
1. Ensure that every caller provides a type. In most cases, we upgrade
the basic yield to sched_relinquish() aka SWT_RELINQUISH.
2. The case of sched_bind() is distinct, so add a new switch type SWT_BIND.
3. Remove the two unused types, SWT_PREEMPT and SWT_SLEEPQTIMO.
4. Remove SWT_NONE altogether and assert that callers always provide
a type flag.
5. Reference the mi_switch(9) man page in the comments, as these flags
will be documented there.
Reviewed by: kib, markj
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D38184
ULE uses the more specific SWT_REMOTEPREEMPT and SWT_REMOTEWAKEIDLE
switch types, let's do that here as well. SWT_PREEMPT is somewhat
redundant when we also have the SW_PREEMPT flag.
This only has an effect for kernels built with SCHED_STATS.
Reviewed by: kib, markj
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D38183
Do this ahead of adding a man page that describes the function. No
functional change.
Reviewed by: kib, markj
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D38181
The equivalent function is now named thread_create(). Mention
kthread_add() where it is also relevant.
Reviewed by: kib, markj
MFC after: 3 days
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D38180
Its purpose is to reserve all I/O space belonging to physical memory
from nexus, preventing it from being handed out by bus_alloc_resource()
to callers such as xenpv_alloc_physmem(), which looks for the first
available free range it can get. This mimics the existing pseudo-driver
on x86.
If needed, the device can be disabled with hint.ram.0.disabled="1" in
/boot/device.hints.
Reviewed by: imp
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D32343
There's no reason to use one over the other here, let's prefer the
interface that's used elsewhere in the kernel.
No functional change intended.
Reviewed by: mjg
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D38360
Summary:
Add 2 new APIs for supporting recent mbuf changes:
* 36e0a362ac added the m_snd_tag_alloc() wrapper around
if_snd_tag_alloc(). Push this down to the ifnet level.
* 4d7a1361ef adds the m_rcvif_serialize()/m_rcvif_restore() KPIs to
serialize and restore an ifnet pointer. Add the necessary wrapper to
get the index generation for this.
Reviewed By: jhb
Sponsored by: Juniper Networks, Inc.
Differential Revision: https://reviews.freebsd.org/D38340
During testing of exporting file systems in jails, I
noticed that the export structures on a mount
were not being free'd when the mount is dismounted.
This bug appears to have been in the system for a
very long time. It would have resulted in a slow memory
leak when exported file systems were dismounted.
Prior to r362158, freeing the structures during dismount
would not have been safe, since VFS_CHECKEXP() returned
a pointer into an export structure, which might still have been
used by the NFS server for an in-progress RPC when the file system
is dismounted. r362158 fixed this, so it should now be safe
to free the structures in vfs_mount_destroy(), which is what
this patch does.
Reviewed by: kib
MFC after: 1 month
Differential Revision: https://reviews.freebsd.org/D38385
Writes on UFS through a mapped region do not allocate disk blocks in
holes immediately. The blocks are allocated when the pages are paged out
first time.
This breaks the algorithm in vn_bmap_seekhole() and ufs_bmap_seekdata(),
because VOP_BMAP() reports hole for the place which already contains a
valid data.
Clean the pages before doing VOP_BMAP() in the affected functions. In
principle, we could clean less by only requesting clean starting from
the offset, but it is probably not very important.
PR: 269261
Reported by: asomers
Reviewed by: asomers, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D38379
mountd(8) basically does the following:
getmntinfo()
for each mount
delete_exports
using nmount(2) to do the creation/deletion of individual exports.
For prison0 (and for other prisons if enforce_statfs == 0) getmntinfo()
returns all mount points, including ones being used within other prisons.
This can cause confusion if the same file system is specified in the
exports(5) file for multiple prisons.
This patch adds a perminent identifier to each prison
and marks which prison did the exports in a field of
the mount structure called mnt_exjail. This field can
then be compared to the perminent identifier for the
prison that the thread's credentials is in.
Also required was a new function called prison_isalive_permid()
which returns if the prison is alive, so that the check can be
ignored for prisons that have been removed.
This prepares the system to allow mountd(8) to run in multiple
prisons, including prison0.
Future commits will complete the modifications to allow mountd(8)
to run in vnet prisons. Until then, these changes should not affect
semantics.
Reviewed by: markj
MFC after: 3 months
Differential Revision: https://reviews.freebsd.org/D38144
Since mountd(8) will not be able to do exports
when running in a vnet prison if enforce_statfs is
set to 0, add a check for this to prison_check_nfsd().
Reviewed by: jamie, markj
MFC after: 2 months
Differential Revision: https://reviews.freebsd.org/D38189
This somewhat undermines the initial goal of sousrsend() to have all
the special error handling for a write on a socket in a single place.
The aio(4) needs to see EWOULDBLOCK to re-schedule the job. Because
aio(4) handles return from soreceive() and sousrsend() with the same
code, we can't check for (error == 0 && done < job_nbytes). Keeping
this exclusion for aio(4) seems a lesser evil.
Fixes: 7a2c93b86e
Since 32c203577a by phk in 1999 (Make even more of the PPSAPI
implementations generic), the "nsec" parameter of hardpps() is a time
difference and no longer a time point. Change the name to "delta_nsec"
and adjust the comment.
Remove comment about a clock tick adjustment which is no longer in the code.
Pull Request: https://github.com/freebsd/freebsd-src/pull/640
Reviewed by: imp
cpuset_which() resolves the argument pair which and id and returns references
to an appropriate resources. To avoid leaking resources or accessing unresolved
references to a resources handle new which CPU_WHICH_TIDPID wherever
cpuset_which() is called.
To avoid code duplication cpuset_which2() has been added.
Reported by: syzbot+331e8402e0f7347f0f2a@syzkaller.appspotmail.com
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D38272
MFC after: 2 weeks
