years ago when the kernel was modified to not alter ABI based on
DIAGNOSTIC, and now just call the respective function interfaces
(in lowercase). Plenty of mix'n match upper/lowercase has creeped
into the tree since then. Nuke the macros and convert all callsites
to lowercase.
no functional change
- Addresses the issue described in PR/38828.
- Some simplification in threading and sleepq subsystems.
- Eliminates pmap_collect() and, as a side note, allows pmap optimisations.
- Eliminates XS_CTL_DATA_ONSTACK in scsipi code.
- Avoids few scans on LWP list and thus potentially long holds of proc_lock.
- Cuts ~1.5k lines of code. Reduces amd64 kernel size by ~4k.
- Removes __SWAP_BROKEN cases.
Tested on x86, mips, acorn32 (thanks <mpumford>) and partly tested on
acorn26 (thanks to <bjh21>).
Discussed on <tech-kern>, reviewed by <ad>.
lookup_for_nfsd(). This code is, or at least should be, the same as
the regular symlink-following code plus an extra flag nfsd needs.
The two lots of code can/will be merged in the future.
private backdoor entry point this is.
Also, clone the lookup_for_nfsd() entry point as
lookup_for_nfsd_index(), for use by a different call site in nfsd that
does different unclean things with nameidata.
the other routines of the same spirit.
Adjust file-system code to use it.
Keep vaccess() for KPI compatibility and to keep element of least
surprise. A "diagnostic" message warning that vaccess() is deprecated will
be printed when it's used (obviously, only in DIAGNOSTIC kernels).
No objections on tech-kern@:
http://mail-index.netbsd.org/tech-kern/2009/06/21/msg005310.html
before feeding it to VOP_GETATTR. it's necessary because the vnode might
be being cleaned by getcleanvnode.
it's an instance of more general races between vnode reclaim and
unlocked VOPs. however, this one happens somewhat often because it can be
triggered by getnewvnode rather than revoke.
being reclaimed by another thread. after recent changes in cache_lookup_raw,
there's a race between cache_lookup_raw/vtryget and getcleanvnode/vclean.
PR/41028.
Fix some of the races (but probably not all of them) in the NFS server code.
nfssvc_nfsd(): change a splsoftclock()/spx() to mutex_enter/exit(&nfsd_lock)
(I guess it was forgotten when the nfsd code was made SMP safe)
m_freem(nd_nam) in nfsrv_slpderef() instead of nfsrv_zapsock() to
avoid possible use after free in nfssvc_nfsd()
Fix nfsrv_slpderef() to not release nfsd_lock before testing SLP_VALID
and reaquiring it just after. This could cause a use after free
of the slp if one thread is in nfsrv_slpderef() and the other one grabs
slp from nfssvc_sockpending and zap it.
nfsrv_rename() can exit without calling genfs_renamelock_exit() because
the nfsm_reply() can do return (0) on error.
Change nfsm_reply to use 'error = 0; goto nfsmout' instead.
Fix a few place so it's safe to goto nfsmout from nfsm_reply, or other
macros calling it.
As a side effect it could fix a missing vrele(dirp) in various place where
nfsm_reply could return(0).
There are still about 1600 left, but they have ',' or /* ... */
in the actual variable definitions - which my awk script doesn't handle.
There are also many that need () -> (void).
(The script does handle misordered arguments.)
than backing off to 256*SRTT. This is why it sometimes could take
hours for a NFS mount to come back when the server returned.
contributed anonymously.
into modules. By and large this commit:
- shuffles header files and ifdefs
- splits code out where necessary to be modular
- adds module glue for each of the components
- adds/replaces hooks for things that can be installed at runtime
- In getpages don't allocate if we are not locked
- Use kmem_alloc instead of malloc and don't sleep
Also provide a 64 entry stack array so we don't have to allocate in the
common case.
constructor instead of depending on link sets. Consequently, rename
nfs_nh{init,reinit,done} to nfs_node_{init,reinit,done}, respectively,
to better convey the function.
case) freed already within the rpc handler.
XXX: this line and another was originally committed with "don't
leak mbufs", but given that currently it can double-free an mbuf
and essentially crash the system, I'll opt for the leak. Needless
to say, this needs revisiting, but that requires a large scale
campaign due to the sticky nature of nfsm love.
Make VFS hooks dynamic while we're here and say farewell to VFS_ATTACH and
VFS_HOOKS_ATTACH linksets.
As a consequence, most of the file systems can now be loaded as new style
modules.
Quick sanity check by ad@.
Simplify the mount locking. Remove all the crud to deal with recursion on
the mount lock, and crud to deal with unmount as another weirdo lock.
Hopefully this will once and for all fix the deadlocks with this. With this
commit there are two locks on each mount:
- krwlock_t mnt_unmounting. This is used to prevent unmount across critical
sections like getnewvnode(). It's only ever read locked with rw_tryenter(),
and is only ever write locked in dounmount(). A write hold can't be taken
on this lock if the current LWP could hold a vnode lock.
- kmutex_t mnt_updating. This is taken by threads updating the mount, for
example when going r/o -> r/w, and is only present to serialize updates.
In order to take this lock, a read hold must first be taken on
mnt_unmounting, and the two need to be held across the operation.
One effect of this change: previously if an unmount failed, we would make a
half hearted attempt to back out of it gracefully, but that was unlikely to
work in a lot of cases. Now while an unmount that will be aborted is in
progress, new file operations within the mount will fail instead of being
delayed. That is unlikely to be a problem though, because if the admin
requests unmount of a file system then s(he) has made a decision to deny
access to the resource.
The previous fix worked, but it opened a window where mounts could have
disappeared from mountlist while the caller was traversing it using
vfs_trybusy(). Fix that.
The symptom was that sometimes file systems would occasionally not appear
in output from 'df' or 'mount' if the system was busy. Resolution:
- Make mount locks work somewhat like vm_map locks.
- vfs_trybusy() now only fails if the mount is gone, or if someone is
unmounting the file system. Simple contention on mnt_lock doesn't
cause it to fail.
- vfs_busy() will wait even if the file system is being unmounted.
proclist_mutex and proclist_lock into a single adaptive mutex (proc_lock).
Implications:
- Inspecting process state requires thread context, so signals can no longer
be sent from a hardware interrupt handler. Signal activity must be
deferred to a soft interrupt or kthread.
- As the proc state locking is simplified, it's now safe to take exit()
and wait() out from under kernel_lock.
- The system spends less time at IPL_SCHED, and there is less lock activity.
