platforms.
This allows to not depend on the IOMMU macro in AHCI driver.
Requested by: kib
Suggested by: andrew
Reviewed by: kib
Sponsored by: Innovate DSbD
Differential Revision: https://reviews.freebsd.org/D26887
The previous scheme for calculating the total size was doing sizeof
on the struct and then adding the wanted space for the buffer.
nc_name is at offset 58 while sizeof(struct namecache) is 64.
With CACHE_PATH_CUTOFF of 39 bytes and 1 byte of padding we were
allocating 104 bytes for the entry and never accounting for the 6
byte padding, wasting that space.
It no longer protects any of tested fields, keeping all the checks racy.
While here make vtryrecycle drop the vnode on its own. Avoids an additional
lock trip.
mkdir -p /foo/bar/baz will mkdir each path component and ignore EEXIST.
The NOCACHE lookup will make the namecache unnecessarily evict the existing entry,
and then fallback to the fs lookup routine eventually leading namei to return an
error as the directory is already there.
For invocations like mkdir -p /usr/obj/usr/src/sys/GENERIC/modules this triggers
fallbacks to the slowpath for concurrently executing lookups.
Tested by: pho
Discussed with: kib
Size of the per-process semaphore undo structure (semusz) depends on
the number of the per-process undos. If kern.ipc.semume is adjusted,
semusz must be adjusted as well, and it makes no sense to delegate
adjustment to user. Make it automatic.
Reported and tested by: Olef <o.vandestadt@gmail.com>
PR: 250361
Reviewed by: jhb, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D26826
Instead, add arguments to vmapbuf. Since this argument is
always a pointer use a type of void * and cast to vm_offset_t in
vmapbuf. (In CheriBSD we've altered vm_fault_quick_hold_pages to
take a pointer and check its bounds.)
In no other situtation does b_data contain a user pointer and vmapbuf
replaces b_data with the actual mapping.
Suggested by: jhb
Reviewed by: imp, jhb
Obtained from: CheriBSD
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26784
It is a common pattern for filesystems' VOP_INACTIVE() implementation
to forcibly reclaim the vnode when its state is final. For instance,
UFS vnode with zero link count is removed, and since it is
inactivated, the last open reference on it is dropped.
On the other hand, vnode might get spurious usecount reference for
many reasons. If the spurious reference exists while vgonel() checks
for active state of the vnode, it would recurse into VOP_INACTIVE().
Fix it by checking and not doing inactivation when vgone() was called
from inactive VOP.
Reported and tested by: pho
Discussed with: mjg
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
During tinderbox and similar workloads negative entries get at least one
hit before they get evicted. In the current scheme this avoidably promotes
them.
Be conservative and stick to 2 hits for now.
The TF_TOE flag is the check used in the rest of the network stack to
determine if TOE is active on a socket. There is at least one path in
the cxgbe(4) TOE driver that can leave the tod pointer non-NULL on a
socket not using TOE.
Reported by: Sony Arpita Das <sonyarpitad@chelsio.com>
Reviewed by: np
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D26803
This will cause the VM to back sufficiently large .text sections, such
as those in zfs.ko or amdgpu.ko on amd64, with superpage mappings when
possible.
Reviewed by: alc, kib
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26802
BT_MAXALLOC (4) is the number of boundary tags required to complete an
allocation in the worst case: two to clip a free segment, and two to
import from a parent arena. vmem_xalloc() preallocates four boundary
tags before attempting a search to simplify the segment allocation code.
It implements a loop that:
1) ensures that BT_MAXALLOC boundary tags are available,
2) attempts to find and clip a free segment satisfying the allocation
constraints, and failing that,
3) attempts to import a segment.
On !UMA_MD_SMALL_ALLOC platforms the btag zone has to handle recusion:
it needs boundary tags to allocate boundary tags. Thus we reserve
2 * BT_MAXALLOC * mp_ncpus tags for use when recursing: the factor of 2
is because there are two layers of vmem arenas, the per-domain arena and
global arena. For a single thread, 2 * BT_MAXALLOC tags should be
sufficient.
Because of the way the loop is structured, BT_MAXALLOC tags are not
sufficient. The first bt_fill() call may allocate BT_MAXALLOC tags,
then import a segment (consuming two tags), then attempt to top up the
preallocation before carving into the imported free segment, thus
requiring up to six tags in the worst case. Because we don't
preallocate that many, this bug can cause deadlocks in rare scenarios.
Fix the problem by moving the preallocation out the loop. This assumes
that only a single import is ever required to satisfy an allocation
request.
Thanks to manu, emaste and lwhsu for helping test debug patches.
Reported by: Jenkins (hardware CI lab)
Reviewed by: alc, kib, rlibby
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D26770
This allows the interrupt controller driver only need a small change to
create a map for the page the device will write to raise an interrupt.
Submitted by: andrew
Reviewed by: kib
Sponsored by: Innovate DSbD
Differential Revision: https://reviews.freebsd.org/D26705
Add a show sysinit command to ddb (similar to show vnet_sysinit) which
proved to be helpful to debug some ordering issues on early-mid kernel
start panics.
The previous scheme only looked at negative entry count in relation to the
total count, leading to tons of spurious evictions if the cache is not
significantly populated.
Instead, only try the above if negative entry count goes beyond namecache
capacity.
Split everything into neg, debug, param and stat categories.
The legacy nchstats sysctl (queried e.g., by systat) remains untouched.
While here rename some vars to be easier on the eye.
- declutter sysctl vfs.cache by moving relevant entries into
vfs.cache.neg
- add a little more parallelism to eviction by replacing the
global lock with an atomically modified counter
- track more statistics
The code needs further effort.
This simplifies the code while allowing for concurrent negative eviction
down the road.
Cache misses increased slightly due to higher rate of evictions allowed by
the change.
The current algorithm remains too aggressive.
Only assign the address from the iovec to bio_data if it is a kernel
address. This was the single place where bio_data stored (however
briefly) a userspace pointer.
Reviewed by: imp, markj
Obtained from: CheriBSD
MFC after: 1 week
Sponsored by: DARPA
Differential Revision: https://reviews.freebsd.org/D26783
Move dump_avail[] extern declaration and inlines into a new header
vm/vm_dumpset.h. This fixes default gcc build for mips.
Reviewed by: alc, scottph
Tested by: kevans (previous version)
Sponsored by: The FreeBSD Foundation
Differential revision: https://reviews.freebsd.org/D26741
Due to a weakness in the TLS 1.0 protocol, OpenSSL will periodically
send empty TLS records ("empty fragments"). These TLS records have no
payload (and thus a page count of zero). m_uiotombuf_nomap() was
returning NULL instead of an empty mbuf, and a few places needed to be
updated to treat an empty TLS record as having a page count of "1" as
0 means "no work to do" (e.g. nothing to encrypt, or nothing to mark
ready via sbready()).
Reviewed by: gallatin
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D26729
Both s_len and s_size are ssize_t, so their differece is also more
properly a ssize_t not a size_t. Also, assert that len is <= size when
we enter. This should always be the case. Ensure that we have that one
byte that we write to the end of the buffer before we do so, though
the error should already be set on the buffer if not, and the only
times we supply 'partial' buffers they should be plenty large.
Reviewed by: cem, jhb (prior version, I did cem's suggestion)
Differential Revsion: https://reviews.freebsd.org/D26752
Push the root seed version to userspace through the VDSO page, if
the RANDOM_FENESTRASX algorithm is enabled. Otherwise, there is no
functional change. The mechanism can be disabled with
debug.fxrng_vdso_enable=0.
arc4random(3) obtains a pointer to the root seed version published by
the kernel in the shared page at allocation time. Like arc4random(9),
it maintains its own per-process copy of the seed version corresponding
to the root seed version at the time it last rekeyed. On read requests,
the process seed version is compared with the version published in the
shared page; if they do not match, arc4random(3) reseeds from the
kernel before providing generated output.
This change does not implement the FenestrasX concept of PCPU userspace
generators seeded from a per-process base generator. That change is
left for future discussion/work.
Reviewed by: kib (previous version)
Approved by: csprng (me -- only touching FXRNG here)
Differential Revision: https://reviews.freebsd.org/D22839
Truncating requires an exclusive lock, but it was not taken if the
filesystem indicates support for shared writes. This only concerns
ZFS.
In particular fixes cp of files which have trailing holes.
Reported by: bdrewery