The fd is always obtained from nameidata, so just fetch it from there
instead. No functional change intended.
Reviewed by: kib
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D43257
Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.
Sponsored by: Netflix
This is a temporary solution to fix PR before release.
During 15.0 it's necessary to refactor symlinks handling
between vfs & namecache.
PR: 273414
Reported by: Vincent Milum Jr, Dan Kotowski, glebius
Tested by: Dan Kotowski, glebius
Reviewed by:
Differential Revision: https://reviews.freebsd.org/D41806
MFC after: 3 days
cache_zap_unlocked_bucket is called with a bunch of addresses and
without any locks held, forcing it to revalidate everything from
scratch.
It did not account for a case where the entry is reallocated with
everything the same except for the target vnode.
Should the target use a different lock than the one expected, freeing
would proceed without being properly synchronized.
Note this is almost impossible to happen in practice.
They are very rarely triggered, so no need for per-cpu distribution.
At the same time the non-cpu ones still should use atomics to not lose
any updates.
While here report a sample result from running on Sapphire Rapids:
An access(2) loop slapped into will-it-scale, like so:
while (1) {
int error = access(tmpfile, R_OK);
assert(error == 0);
(*iterations)++;
}
.. operating on /usr/obj/usr/src/amd64.amd64/sys/GENERIC/vnode_if.c
In operations per second:
lockless: 3462164
locked: 1362376
While the over 3.4 mln may seem like a big number, a critical look shows
it should be significantly higher.
A poor man's profiler, counting how many times given routine was sampled:
dtrace -w -n 'profile:::profile-4999 /execname == "a.out"/ {
@[sym(arg0)] = count(); } tick-5s { system("clear"); trunc(@, 40);
printa("%40a %@16d\n", @); clear(@); }'
[snip]
kernel`kern_accessat 231
kernel`cpu_fetch_syscall_args 324
kernel`cache_fplookup_cross_mount 340
kernel`namei 346
kernel`amd64_syscall 352
kernel`tmpfs_fplookup_vexec 388
kernel`vput 467
kernel`vget_finish 499
kernel`lockmgr_unlock 529
kernel`lockmgr_slock 558
kernel`vget_prep_smr 571
kernel`vput_final 578
kernel`vdropl 1070
kernel`memcmp 1174
kernel`0xffffffff80 2080
0x0 2231
kernel`copyinstr_smap 2492
kernel`cache_fplookup 9246
'ncnegminpct' is to be passed always, so just drop the unneeded parameter.
Sponsored by: The FreeBSD Foundation
Reviewed by: mjg
Differential Revision: https://reviews.freebsd.org/D41763
Overflow in cache_changesize would make the value flip to 0 and stay
there as 0 << 1 does not do anything.
Note callers limit the outcome to something below u_int.
Also note there entire vnode handling thing both in vfs layer as a whole
and this file can't decide whether to long, u_long or u_int.
before calling vn_fullpath_hardlink(). Otherwise we get random failures
when the len is automatically clipped.
Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
For now a non-native ABI (i.e., Linux) uses the kern_alternate_path()
facility to dynamically reroot lookups. First, an attempt is made to
lookup the file in /compat/linux/original-path. If that fails, the
lookup is done in /original-path. Thats requires a bit of code in
every ABI syscall implementation where path name translation is needed.
Also our kern_alternate_path() does not properly lookups absolute symlinks
in second attempt, i.e., does not append /compat/linux part to the resolved
link.
The change is intended to avoid this by specifiyng the ABI root directory
for namei(), using one call to pwd_altroot() during exec-time into the ABI.
In that case namei() will dynamically reroot lookups as mentioned above.
PR: 72920
Reviewed by: kib
Differential revision: https://reviews.freebsd.org/D38933
MFC after: 2 month
Two vfs.cache.stats names are fixed:
- s/.dotdothis/.dotdothits/
- s/.posszaps/.poszaps/
Signed-off-by: Igor Ostapenko <pm@igoro.pro>
[mjg: massaged the header a little bit]
For file mounts, the directory vnode is not available from namei and this
prevents the use of vn_fullpath_hardlink. In this case, we can use the
vnode which was covered by the file mount with vn_fullpath.
This also disallows file mounts over files with link counts greater than
one to ensure a deterministic path to the mount point.
Reviewed by: mjg, kib
Tested by: pho
This removes some of the complexity needed to maintain HASBUF and
allows for removing injecting SAVENAME by filesystems.
Reviewed by: kib (previous version)
Differential Revision: https://reviews.freebsd.org/D36542
This avoids spurious drop offs as EMPTY is passed regardless of the
actual path name.
Pushign the work inside the lookup instead of just ignorign the flag
allows avoid checking for empty pathname for all other lookups.
