- Centralize vnode kevent handling in the VOP_*() wrappers, rather than
forcing each individual file system to deal with it (except VOP_RENAME(),
because VOP_RENAME() is a mess and we currently have 2 different ways
of handling it; at least it's reasonably well-centralized in the "new"
way).
- Add support for NOTE_OPEN, NOTE_CLOSE, NOTE_CLOSE_WRITE, and NOTE_READ,
compatible with the same events in FreeBSD.
- Track which kevent notifications clients are interested in receiving
to avoid doing work for events no one cares about (avoiding, e.g.
taking locks and traversing the klist to send a NOTE_WRITE when
someone is merely watching for a file to be deleted, for example).
In support of the above:
- Add support in vnode_if.sh for specifying PRE- and POST-op handlers,
to be invoked before and after vop_pre() and vop_post(), respectively.
Basic idea from FreeBSD, but implemented differently.
- Add support in vnode_if.sh for specifying CONTEXT fields in the
vop_*_args structures. These context fields are used to convey information
between the file system VOP function and the VOP wrapper, but do not
occupy an argument slot in the VOP_*() call itself. These context fields
are initialized and subsequently interpreted by PRE- and POST-op handlers.
- Version VOP_REMOVE(), uses the a context field for the file system to report
back the resulting link count of the target vnode. Return this in tmpfs,
udf, nfs, chfs, ext2fs, lfs, and ufs.
NetBSD 9.99.92.
The poorly named uvm.h is generally supposed to be for uvm-internal
users only.
- Narrow it to files that actually need it -- mostly files that need
to query whether curlwp is the pagedaemon, which should maybe be
exposed by an external header.
- Use uvm_extern.h where feasible and uvm_*.h for things not exposed
by it. We should split up uvm_extern.h but this will serve for now
to reduce the uvm.h dependencies.
- Use uvm_stat.h and #ifdef UVMHIST uvm.h for files that use
UVMHIST(ubchist), since ubchist is declared in uvm.h but the
reference evaporates if UVMHIST is not defined, so we reduce header
file dependencies.
- Make uvm_device.h and uvm_swap.h independently includable while
here.
ok chs@
- Add new flag UBC_ISMAPPED which tells ubc_uiomove() the object is mmap()ed
somewhere. Use it to decide whether to do direct-mapped copy, rather than
poking around directly in the vnode in ubc_uiomove(), which is ugly and
doesn't work for tmpfs. It would be nicer to contain all this in UVM but
the filesystem provides the needed locking here (VV_MAPPED) and to
reinvent that would suck more.
- Rename UBC_UNMAP_FLAG() to UBC_VNODE_FLAGS(). Pass in UBC_ISMAPPED where
appropriate.
and getcwd():
- push vnode locking back as far as possible.
- do most lookups directly in the namecache, avoiding vnode locks & refs.
- don't block new refs to vnodes across VOP_INACTIVE().
- get shared locks for VOP_LOOKUP() if the file system supports it.
- correct lock types for VOP_ACCESS() / VOP_GETATTR() in a few places.
Possible future enhancements:
- make the lookups lockless.
- support dotdot lookups by being lockless and inferring absence of chroot.
- maybe make it work for layered file systems.
- avoid vnode references at the root & cwd.
- Change the lock on uvm_object, vm_amap and vm_anon to be a RW lock.
- Break v_interlock and vmobjlock apart. v_interlock remains a mutex.
- Do partial PV list locking in the x86 pmap. Others to follow later.
- Use tmpfs node address as key.
- Remove tn_vlock, field tn_vnode now protected by vcache.
- Add a hold count to tmpfs node to prevent nodes from disappearing
while tmpfs_fhtovp() trys to vcache_get() them. Last holder
destroys reclaimed nodes.
- Remove the now unneeded parent unlock/lock for lookup of '..'.
tmpfs_reclaim() before the call to tmpfs_free_node(). Thread2
runs VFS_FHTOVP() and gets a new vnode attached to the node thread1
is about to destroy.
Change tmpfs_alloc_node() to always assign non-zero generation number
and tmpfs_inactive() to set the generation number of unlinked nodes
to zero.
timestamp updates. Fix some incorrect updates and plug some missing ones.
Should fix PR/48385.
- tmpfs_rmdir: avoid O(n) scan when the directory is not empty and whiteout
entries were never added.
address truncated to 31 bits (required for 32-bit readdir compatibility,
e.g. linux32). Instead, assign 2^31 range using the following logic:
- The first half of the 2^31 is assigned incrementally (the fast path).
- When exceeded, use the second half of 2^31, but manage with vmem(9).
It will require 2 billion files per-directory to trigger vmem(9) usage.
Also, while here, add some fixes for tmpfs_unmount().
Should fix PR/47739, PR/47480, PR/46088 and PR/41068.
Thanks to wiz@ for stress testing.
<20111022023242.BA26F14A158@mail.netbsd.org>. This change includes
the following:
An initial cleanup and minor reorganization of the entropy pool
code in sys/dev/rnd.c and sys/dev/rndpool.c. Several bugs are
fixed. Some effort is made to accumulate entropy more quickly at
boot time.
A generic interface, "rndsink", is added, for stream generators to
request that they be re-keyed with good quality entropy from the pool
as soon as it is available.
The arc4random()/arc4randbytes() implementation in libkern is
adjusted to use the rndsink interface for rekeying, which helps
address the problem of low-quality keys at boot time.
An implementation of the FIPS 140-2 statistical tests for random
number generator quality is provided (libkern/rngtest.c). This
is based on Greg Rose's implementation from Qualcomm.
A new random stream generator, nist_ctr_drbg, is provided. It is
based on an implementation of the NIST SP800-90 CTR_DRBG by
Henric Jungheim. This generator users AES in a modified counter
mode to generate a backtracking-resistant random stream.
An abstraction layer, "cprng", is provided for in-kernel consumers
of randomness. The arc4random/arc4randbytes API is deprecated for
in-kernel use. It is replaced by "cprng_strong". The current
cprng_fast implementation wraps the existing arc4random
implementation. The current cprng_strong implementation wraps the
new CTR_DRBG implementation. Both interfaces are rekeyed from
the entropy pool automatically at intervals justifiable from best
current cryptographic practice.
In some quick tests, cprng_fast() is about the same speed as
the old arc4randbytes(), and cprng_strong() is about 20% faster
than rnd_extract_data(). Performance is expected to improve.
The AES code in src/crypto/rijndael is no longer an optional
kernel component, as it is required by cprng_strong, which is
not an optional kernel component.
The entropy pool output is subjected to the rngtest tests at
startup time; if it fails, the system will reboot. There is
approximately a 3/10000 chance of a false positive from these
tests. Entropy pool _input_ from hardware random numbers is
subjected to the rngtest tests at attach time, as well as the
FIPS continuous-output test, to detect bad or stuck hardware
RNGs; if any are detected, they are detached, but the system
continues to run.
A problem with rndctl(8) is fixed -- datastructures with
pointers in arrays are no longer passed to userspace (this
was not a security problem, but rather a major issue for
compat32). A new kernel will require a new rndctl.
The sysctl kern.arandom() and kern.urandom() nodes are hooked
up to the new generators, but the /dev/*random pseudodevices
are not, yet.
Manual pages for the new kernel interfaces are forthcoming.
- Enable VOP tmpfs_whiteout().
- Support ISWHITEOUT in tmpfs_alloc_file().
- Support DOWHITEOUT in tmpfs_remove() and tmpfs_rmdir().
- Make rmdir on a directory containing whiteouts working.
Should fix PR #35112 (tmpfs doesn't play well with unionfs).
ubc_zerorange(struct uvm_object *, off_t, size_t, int) changing
the first argument to an uvm_object and adding a flags argument.
Modify tmpfs_reg_resize() to zero the backing store (aobj) instead
of the vnode. Ubc_purge() no longer panics when unmounting tmpfs.
Keep uvm_vnp_zerorange() until the next kernel version bump.
- Reorganize locking in UVM and provide extra serialisation for pmap(9).
New lock order: [vmpage-owner-lock] -> pmap-lock.
- Simplify locking in some pmap(9) modules by removing P->V locking.
- Use lock object on vmobjlock (and thus vnode_t::v_interlock) to share
the locks amongst UVM objects where necessary (tmpfs, layerfs, unionfs).
- Rewrite and optimise x86 TLB shootdown code, make it simpler and cleaner.
Add TLBSTATS option for x86 to collect statistics about TLB shootdowns.
- Unify /dev/mem et al in MI code and provide required locking (removes
kernel-lock on some ports). Also, avoid cache-aliasing issues.
Thanks to Andrew Doran and Joerg Sonnenberger, as their initial patches
formed the core changes of this branch.
cycle (destruction part). Perform link counting in tmpfs_dir_attach()
and tmpfs_dir_detach(), instead of alloc/free and arbitrary places.
Fixes PR/44285, PR/44288, PR/44657 and likely PR/42484.
- Fix the race between the lookup and inode destruction. Fixes PR/43167
and its duplicates PR/40088, PR/40757.
- Improve tmpfs_rename() locking a little, fix kqueue event notifications
and also fix PR/43617. Add simplistic tmpfs_parentcheck_p(); to be
expanded and used for further rename() locking fixes.
- Cache directory entry "hint" in the tmpfs node, add tmpfs_dir_cached(),
and thus avoid unnecessary lookup in tmpfs_remove() and tmpfs_rmdir().
- Set correct _PC_FILESIZEBITS value in tmpfs_pathconf(). Fixes PR/43576.
- Few minor fixes.
thorpej