Typos.

Remove now obsolete operation vcache_remove().

Welcome to 7.99.36

branches: 1.36.2;
Do not uselessly include <sys/malloc.h>.

Fix PUFFS node use-after-reclaim

When puffs_cookie2vnode() misses an entry, vcache_get()
creates a new node (puffs_vfsop_loadvnode being called to
initialize the PUFFS part), then it discovers it is VNON,
and tries to vrele() it. vrele() calls VOP_INACTIVE(),
which led us in puffs_vnop_inactive() where we sent a
request to the filesystem for a node that already had been
reclaimed.

The fix is to check for VNON nodes in puffs_vnop_inactive()
and to return without doing anyting. This is suboptimal, but
a better workaround would probably need to modify vcache API,
with an impact on other filesystems. Let us keep it simple.

Fix the puffs_sop_thread -> puffs_cookie2vnode path:
- pass the cookie by reference
- add missing mutex_exit()
- update assertion for VNON typed vnodes

When changing a directory content, update the ctime/mtime in kernel cache,
otherwise the updated ctime/mtime appears after the cached entry expire.

Change puffs from hashlist to vcache.
- field "pa_nhashbuckets" of struct "puffs_kargs" becomes a no-op.
and should be removed on the next protocol version bump.

branches: 1.31.4;
Change vnode operations create, mknod, mkdir and symlink to return
the resulting vnode *vpp unlocked.

Discussed on tech-kern@

Welcome to 6.99.30

- remove unused variables
- add _NOERROR flavor macros for the case where errors are ignored.

branches: 1.29.6;
comments
use sizeof(var) instead of sizeof(type) where possibly confusing

Excise struct componentname from the namecache.

This uglifies the interface, because several operations need to be
passed the namei flags and cache_lookup also needs for the time being
to be passed cnp->cn_nameiop. Nonetheless, it's a net benefit.

The glop should be able to go away eventually but requires structural
cleanup elsewhere first.

This change requires a kernel bump.

branches: 1.27.2;
Backout NCHNAMLEN check for cache_enter. That change collided with rmind's
move of this exact check into cache_enter

Di not call cache_enter with path components bigger than NCHNAMLEN, as it
panics the kernel.

Move some the test for MAKEENTRY into the cache_enter(9). Make some
variables in vfs_cache.c static, __read_mostly, etc.

No objection on tech-kern@.

Add name and atttribute cache with filesytem provided TTL.
lookup, create, mknod, mkdir, symlink, getattr and setattr messages
have been extended so that attributes and their TTL can be provided
by the filesytem. lookup, create, mknod, mkdir, and symlink messages
are also extended so that the filesystem can provide name TTL.

branches: 1.23.2;
Fix a race condition where the filesystem lookups a vnode that is
being recycled, producing ENOENT while the file does exist.

Approved by yamt

branches: 1.22.2; 1.22.6;
Remove #ifdef DIAGNOSTIC guards around KASSERT, as the macro contains them

Make sure pagedaemon does not sleep for memory in puffs_vnop_sleep.
Add KASSERT on any sleeping memory allocation to check it cannot happen again.

Add a mutex for operations that touch size (setattr, getattr, write, fsync).

This is required to avoid data corruption bugs, where a getattr slices
itself within a setattr operation, and sets the size to the stall value
it got from the filesystem. That value is smaller than the one set by
setattr, and the call to uvm_vnp_setsize() trigged a spurious truncate.
The result is a chunk of zeroed data in the file.

Such a situation can easily happen when the ioflush thread issue a
VOP_FSYNC/puffs_vnop_sync/flushvncache/dosetattrn while andother process
do a sys_stat/VOP_GETATTR/puffs_vnop_getattr.

This mutex on size operation can be removed the day we decide VOP_GETATTR
has to operated on a locked vnode, since the other operations that touch
size already require that.

dependant -> dependent

Welcome to 5.99.53! Merge rmind-uvmplock branch:

- 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.

branches: 1.17.6;
It makes no sense to call vget() with LK_RETRY.

Make holding v_interlock mandatory for callers of vget().

Announced some time ago on tech-kern.

branches: 1.15.2; 1.15.4;
Kill suspend support. It was never implemented correctly:
* it depended on the biglock (in a very cruel way)
* it was attached to userspace transactions rather than logical
fs operations

(If someone wants to revisit it some day, most of the stuff can be
reused from cvs history)

* fix a race i introduced almost two years ago in rev 1.116:
operations creating a node cannot be considered outgoing operations,
since after return from userspace they modify file system state
by creating a new node. if we do not protect the file system by
holding the directory lock, a lookup operation might race us into
the kernel and create the node earlier.
* remove pnode from hashlish before sending the reclaim faf off to
userspace. also, hold pmp_lock while frobbing the list.

branches: 1.13.10; 1.13.18;
PR kern/37950 Unmounting psshfs immediately panics the machine

puffs_getvnode() was inserting vnodes into mnt_vnodelist without taking
a reference to the mount for each. When vnodes are scrubbed, refs to the
vnodes mount structure are dropped => boom.

branches: 1.12.2; 1.12.4;
Welcome to 4.99.55:

- Add a lot of missing selinit() and seldestroy() calls.

- Merge selwakeup() and selnotify() calls into a single selnotify().

- Add an additional 'events' argument to selnotify() call. It will
indicate which event (POLL_IN, POLL_OUT, etc) happen. If unknown,
zero may be used.

Note: please pass appropriate value of 'events' where possible.
Proposed on: <tech-kern>

branches: 1.11.2; 1.11.6;
For code clarity typedef void *puffs_cookie_t.

No functional change.

specfs changes for PR kern/37717 (raidclose() is no longer called on
shutdown). There are still problems with device access and a PR will be
filed.

- Kill checkalias(). Allow multiple vnodes to reference a single device.

- Don't play dangerous tricks with block vnodes to ensure that only one
vnode can describe a block device. Instead, prohibit concurrent opens of
block devices. As a bonus remove the unreliable code that prevents
multiple file system mounts on the same device. It's no longer needed.

- Track opens by vnode and by device. Issue cdev_close() when the last open
goes away, instead of abusing vnode::v_usecount to tell if the device is
open.

Merge vmlocking2 to head.

branches: 1.8.2; 1.8.6;
Make puffs_updatenode() take a puffs_node instead of a vnode. This
way we don't need to worry if a vnode has been reclaimed from under
us.

Restructure the messaging interface a bit more: make all interfacing
with the file server happen through puffs_msg_enqueue() and
puffs_msg_wait() instead of having a billion different routines.
Build the existing system upon these two. Most importantly though,
decouple insertation into the op queue from the actual wait. This
is useful for a number of reasons coming soon to a cvs repo near you.

branches: 1.6.2; 1.6.4; 1.6.6; 1.6.8;
Part 1/n of some pretty extensive changes to how the kernel module
interacts with the userspace file server:

* since the kernel-user communication is not purely request-response
anymore (hasn't been since 2006), try to rename some "request" to
"message". more similar mangling will take place in the future.

* completely rework how messages are allocated. previously most of
them were borrowed from the stack (originally *all* of them),
but now always allocate dynamically. this makes the structure
of the code much cleaner. also makes it possible to fix a
locking order violation. it enables plenty of future enhancements.

* start generalizing the transport interface to be independent of puffs

* move transport interface to read/write instead of ioctl. the
old one had legacy design problems, and besides, ioctl's suck.
implement a very generic version for now; this will be
worked on later hopefully some day reaching "highly optimized".

* implement libpuffs support behind existing library request
interfaces. this will change eventually (I hate those interfaces)

Merge from vmlocking:

- Split vnode::v_flag into three fields, depending on field locking.
- simple_lock -> kmutex in a few places.
- Fix some simple locking problems.

branches: 1.4.2; 1.4.4; 1.4.6;
If kernel resource allocation fails after the file server has
committed something, issue an abort. The abort is done through
the regular op channel, e.g. failed mkdir leads to regular rmdir,
inactive and reclaim. No internal interface is planned currently
for the one file system out of a million which would implement it
to benefit from the one case in a billion where kernel resource
allocation actually does fail and out of that one case in a trillion
where internal vs. external would make a difference.

* better error checking: validate error values received from userland
to be vaild errno values
* include string describing error in PUFFS_ERR
* get rid of union in puffs_req, it's nothing but trouble
* pass pmp to async i/o callbacks

comments & other minor maintenance

Split routines handling nodes from puffs_subr to puffs_node.
No functional change.

Remove now obsolete operation vcache_remove().

Welcome to 7.99.36

branches: 1.36.2;
Do not uselessly include <sys/malloc.h>.

Fix PUFFS node use-after-reclaim

When puffs_cookie2vnode() misses an entry, vcache_get()
creates a new node (puffs_vfsop_loadvnode being called to
initialize the PUFFS part), then it discovers it is VNON,
and tries to vrele() it. vrele() calls VOP_INACTIVE(),
which led us in puffs_vnop_inactive() where we sent a
request to the filesystem for a node that already had been
reclaimed.

The fix is to check for VNON nodes in puffs_vnop_inactive()
and to return without doing anyting. This is suboptimal, but
a better workaround would probably need to modify vcache API,
with an impact on other filesystems. Let us keep it simple.

Fix the puffs_sop_thread -> puffs_cookie2vnode path:
- pass the cookie by reference
- add missing mutex_exit()
- update assertion for VNON typed vnodes

When changing a directory content, update the ctime/mtime in kernel cache,
otherwise the updated ctime/mtime appears after the cached entry expire.

Change puffs from hashlist to vcache.
- field "pa_nhashbuckets" of struct "puffs_kargs" becomes a no-op.
and should be removed on the next protocol version bump.

branches: 1.31.4;
Change vnode operations create, mknod, mkdir and symlink to return
the resulting vnode *vpp unlocked.

Discussed on tech-kern@

Welcome to 6.99.30

- remove unused variables
- add _NOERROR flavor macros for the case where errors are ignored.

branches: 1.29.6;
comments
use sizeof(var) instead of sizeof(type) where possibly confusing

Excise struct componentname from the namecache.

This uglifies the interface, because several operations need to be
passed the namei flags and cache_lookup also needs for the time being
to be passed cnp->cn_nameiop. Nonetheless, it's a net benefit.

The glop should be able to go away eventually but requires structural
cleanup elsewhere first.

This change requires a kernel bump.

branches: 1.27.2;
Backout NCHNAMLEN check for cache_enter. That change collided with rmind's
move of this exact check into cache_enter

Di not call cache_enter with path components bigger than NCHNAMLEN, as it
panics the kernel.

Move some the test for MAKEENTRY into the cache_enter(9). Make some
variables in vfs_cache.c static, __read_mostly, etc.

No objection on tech-kern@.

Add name and atttribute cache with filesytem provided TTL.
lookup, create, mknod, mkdir, symlink, getattr and setattr messages
have been extended so that attributes and their TTL can be provided
by the filesytem. lookup, create, mknod, mkdir, and symlink messages
are also extended so that the filesystem can provide name TTL.

branches: 1.23.2;
Fix a race condition where the filesystem lookups a vnode that is
being recycled, producing ENOENT while the file does exist.

Approved by yamt

branches: 1.22.2; 1.22.6;
Remove #ifdef DIAGNOSTIC guards around KASSERT, as the macro contains them

Make sure pagedaemon does not sleep for memory in puffs_vnop_sleep.
Add KASSERT on any sleeping memory allocation to check it cannot happen again.

Add a mutex for operations that touch size (setattr, getattr, write, fsync).

This is required to avoid data corruption bugs, where a getattr slices
itself within a setattr operation, and sets the size to the stall value
it got from the filesystem. That value is smaller than the one set by
setattr, and the call to uvm_vnp_setsize() trigged a spurious truncate.
The result is a chunk of zeroed data in the file.

Such a situation can easily happen when the ioflush thread issue a
VOP_FSYNC/puffs_vnop_sync/flushvncache/dosetattrn while andother process
do a sys_stat/VOP_GETATTR/puffs_vnop_getattr.

This mutex on size operation can be removed the day we decide VOP_GETATTR
has to operated on a locked vnode, since the other operations that touch
size already require that.

dependant -> dependent

Welcome to 5.99.53! Merge rmind-uvmplock branch:

- 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.

branches: 1.17.6;
It makes no sense to call vget() with LK_RETRY.

Make holding v_interlock mandatory for callers of vget().

Announced some time ago on tech-kern.

branches: 1.15.2; 1.15.4;
Kill suspend support. It was never implemented correctly:
* it depended on the biglock (in a very cruel way)
* it was attached to userspace transactions rather than logical
fs operations

(If someone wants to revisit it some day, most of the stuff can be
reused from cvs history)

* fix a race i introduced almost two years ago in rev 1.116:
operations creating a node cannot be considered outgoing operations,
since after return from userspace they modify file system state
by creating a new node. if we do not protect the file system by
holding the directory lock, a lookup operation might race us into
the kernel and create the node earlier.
* remove pnode from hashlish before sending the reclaim faf off to
userspace. also, hold pmp_lock while frobbing the list.

branches: 1.13.10; 1.13.18;
PR kern/37950 Unmounting psshfs immediately panics the machine

puffs_getvnode() was inserting vnodes into mnt_vnodelist without taking
a reference to the mount for each. When vnodes are scrubbed, refs to the
vnodes mount structure are dropped => boom.

branches: 1.12.2; 1.12.4;
Welcome to 4.99.55:

- Add a lot of missing selinit() and seldestroy() calls.

- Merge selwakeup() and selnotify() calls into a single selnotify().

- Add an additional 'events' argument to selnotify() call. It will
indicate which event (POLL_IN, POLL_OUT, etc) happen. If unknown,
zero may be used.

Note: please pass appropriate value of 'events' where possible.
Proposed on: <tech-kern>

branches: 1.11.2; 1.11.6;
For code clarity typedef void *puffs_cookie_t.

No functional change.

specfs changes for PR kern/37717 (raidclose() is no longer called on
shutdown). There are still problems with device access and a PR will be
filed.

- Kill checkalias(). Allow multiple vnodes to reference a single device.

- Don't play dangerous tricks with block vnodes to ensure that only one
vnode can describe a block device. Instead, prohibit concurrent opens of
block devices. As a bonus remove the unreliable code that prevents
multiple file system mounts on the same device. It's no longer needed.

- Track opens by vnode and by device. Issue cdev_close() when the last open
goes away, instead of abusing vnode::v_usecount to tell if the device is
open.

Merge vmlocking2 to head.

branches: 1.8.2; 1.8.6;
Make puffs_updatenode() take a puffs_node instead of a vnode. This
way we don't need to worry if a vnode has been reclaimed from under
us.

Restructure the messaging interface a bit more: make all interfacing
with the file server happen through puffs_msg_enqueue() and
puffs_msg_wait() instead of having a billion different routines.
Build the existing system upon these two. Most importantly though,
decouple insertation into the op queue from the actual wait. This
is useful for a number of reasons coming soon to a cvs repo near you.

branches: 1.6.2; 1.6.4; 1.6.6; 1.6.8;
Part 1/n of some pretty extensive changes to how the kernel module
interacts with the userspace file server:

* since the kernel-user communication is not purely request-response
anymore (hasn't been since 2006), try to rename some "request" to
"message". more similar mangling will take place in the future.

* completely rework how messages are allocated. previously most of
them were borrowed from the stack (originally *all* of them),
but now always allocate dynamically. this makes the structure
of the code much cleaner. also makes it possible to fix a
locking order violation. it enables plenty of future enhancements.

* start generalizing the transport interface to be independent of puffs

* move transport interface to read/write instead of ioctl. the
old one had legacy design problems, and besides, ioctl's suck.
implement a very generic version for now; this will be
worked on later hopefully some day reaching "highly optimized".

* implement libpuffs support behind existing library request
interfaces. this will change eventually (I hate those interfaces)

Merge from vmlocking:

- Split vnode::v_flag into three fields, depending on field locking.
- simple_lock -> kmutex in a few places.
- Fix some simple locking problems.

branches: 1.4.2; 1.4.4; 1.4.6;
If kernel resource allocation fails after the file server has
committed something, issue an abort. The abort is done through
the regular op channel, e.g. failed mkdir leads to regular rmdir,
inactive and reclaim. No internal interface is planned currently
for the one file system out of a million which would implement it
to benefit from the one case in a billion where kernel resource
allocation actually does fail and out of that one case in a trillion
where internal vs. external would make a difference.

* better error checking: validate error values received from userland
to be vaild errno values
* include string describing error in PUFFS_ERR
* get rid of union in puffs_req, it's nothing but trouble
* pass pmp to async i/o callbacks

comments & other minor maintenance

Split routines handling nodes from puffs_subr to puffs_node.
No functional change.