Access to `u_flags' should be serialized by the `vmobjlock'.

This complete previous fix from gnezdo@. The uvm_vnp_sync() still
requires some love and isn't addressed by this diff.

Document which lock is protecting vnode variables.

ok gnezdo@

Revert UVM_VNODE_CANPERSIST removal, it exposes an issue on arm64.

Found the hardway by miod@ and deraadt@.

Get rid of the extra vnode reference known as UVM_VNODE_CANPERSIST.

Back in the 4.4BSD days the VM subystem had a OBJ_CANPERSIST flag to
enter objects in a global cached list. Some of this logic seem to have
been copied to UVM but without the global list.

Unfortunately keeping UVM vnode objects alive after munmap(2)ing the
corresponding region without incrementing the reference count of the
related vnode led to many bugs when the vnode was recycled and/or when
it data where written back to disk (via the page daemon).

The problem is that VM pages might have a non-accounted reference to a
vnode via `pg->uobject'.

Fix "vref used where vget required" panic reported by bluhm@, gkoehler@
and Andrew Krasavinseen on bugs@.

Thanks a lot to semarie@ for co-debugging this issue!

Tested by bluhm@, tb@, miod@.

ok kettenis@, semarie@

Revert the fix for the deadlock between uvn_io() and uvn_flush().

This fix (ab)use the vnode lock to serialize access to some fields of
the corresponding pages associated with UVM vnode object and this will
create new deadlocks with the introduction of a per-uobj lock.

ok anton@

Bring back previous fix for UVM vnode deadlock.

tb@ reports that refaulting when there's contention on the vnode makes
firefox start very slowly on his machine. To revisit when the fault
handler will be unlocked.

ok anton@

Original commit message:

Fix a deadlock between uvn_io() and uvn_flush(). While faulting on a
page backed by a vnode, uvn_io() will end up being called in order to
populate newly allocated pages using I/O on the backing vnode. Before
performing the I/O, newly allocated pages are flagged as busy by
uvn_get(), that is before uvn_io() tries to lock the vnode. Such pages
could then end up being flushed by uvn_flush() which already has
acquired the vnode lock. Since such pages are flagged as busy,
uvn_flush() will wait for them to be flagged as not busy. This will
never happens as uvn_io() cannot make progress until the vnode lock is
released.

Instead, grab the vnode lock before allocating and flagging pages as
busy in uvn_get(). This does extend the scope in uvn_get() in which the
vnode is locked but resolves the deadlock.

ok mpi@

Reported-by: syzbot+e63407b35dff08dbee02@syzkaller.appspotmail.com

Revert the fix for the deadlock between uvn_io() and uvn_flush().

This fix (ab)use the vnode lock to serialize access to some fields of
the corresponding pages associated with UVM vnode object and this will
create new deadlocks with the introduction of a per-uobj lock.

ok anton@

Fix a deadlock between uvn_io() and uvn_flush(). While faulting on a
page backed by a vnode, uvn_io() will end up being called in order to
populate newly allocated pages using I/O on the backing vnode. Before
performing the I/O, newly allocated pages are flagged as busy by
uvn_get(), that is before uvn_io() tries to lock the vnode. Such pages
could then end up being flushed by uvn_flush() which already has
acquired the vnode lock. Since such pages are flagged as busy,
uvn_flush() will wait for them to be flagged as not busy. This will
never happens as uvn_io() cannot make progress until the vnode lock is
released.

Instead, grab the vnode lock before allocating and flagging pages as
busy in uvn_get(). This does extend the scope in uvn_get() in which the
vnode is locked but resolves the deadlock.

ok mpi@

Reported-by: syzbot+e63407b35dff08dbee02@syzkaller.appspotmail.com

primary change: move uvm_vnode out of vnode, keeping only a pointer.
objective: vnode.h doesn't include uvm_extern.h anymore.
followup changes: include uvm_extern.h or lock.h where necessary.
ok and help from deraadt

delete a #ifdef _KERNEL chunk protecting userland from an #if 0 chunk

First round of __P removal in sys

UBC was a disaster. It worked very good when it worked, but on some
machines or some configurations or in some phase of the moon (we actually
don't know when or why) files disappeared. Since we've not been able to
track down the problem in two weeks intense debugging and we need -current
to be stable, back out everything to a state it had before UBC.

We apologise for the inconvenience.

Merge in struct uvm_vnode into struct vnode.

Merge in the unified buffer cache code as found in NetBSD 2001/03/10. The
code is written mostly by Chuck Silvers <chuq@chuq.com>/<chs@netbsd.org>.

Tested for the past few weeks by many developers, should be in a pretty stable
state, but will require optimizations and additional cleanups.

Add a new type voff_t (right now it's typedefed as off_t) used for offsets
into objects.

Gives the possibilty to mmap beyond the size of vaddr_t.

From NetBSD.

Sync style, typo, and comments a little closer to NetBSD. art@ ok

Protect protypes, certain macros, and inlines from userland. Checked userland
with a 'make build'. From NetBSD. art@ ok

$OpenBSD$

Fix the NetBSD id strings.

branches: 1.3.4;
sync with NetBSD from 1999.05.24 (there is a reason for this date)
Mostly cleanups, but also a few improvements to pagedaemon for better
handling of low memory and/or low swap conditions.

add OpenBSD tags

Import of uvm from NetBSD. Some local changes, some code disabled

Revert UVM_VNODE_CANPERSIST removal, it exposes an issue on arm64.

Found the hardway by miod@ and deraadt@.

Get rid of the extra vnode reference known as UVM_VNODE_CANPERSIST.

Back in the 4.4BSD days the VM subystem had a OBJ_CANPERSIST flag to
enter objects in a global cached list. Some of this logic seem to have
been copied to UVM but without the global list.

Unfortunately keeping UVM vnode objects alive after munmap(2)ing the
corresponding region without incrementing the reference count of the
related vnode led to many bugs when the vnode was recycled and/or when
it data where written back to disk (via the page daemon).

The problem is that VM pages might have a non-accounted reference to a
vnode via `pg->uobject'.

Fix "vref used where vget required" panic reported by bluhm@, gkoehler@
and Andrew Krasavinseen on bugs@.

Thanks a lot to semarie@ for co-debugging this issue!

Tested by bluhm@, tb@, miod@.

ok kettenis@, semarie@

Revert the fix for the deadlock between uvn_io() and uvn_flush().

This fix (ab)use the vnode lock to serialize access to some fields of
the corresponding pages associated with UVM vnode object and this will
create new deadlocks with the introduction of a per-uobj lock.

ok anton@

Bring back previous fix for UVM vnode deadlock.

tb@ reports that refaulting when there's contention on the vnode makes
firefox start very slowly on his machine. To revisit when the fault
handler will be unlocked.

ok anton@

Original commit message:

Fix a deadlock between uvn_io() and uvn_flush(). While faulting on a
page backed by a vnode, uvn_io() will end up being called in order to
populate newly allocated pages using I/O on the backing vnode. Before
performing the I/O, newly allocated pages are flagged as busy by
uvn_get(), that is before uvn_io() tries to lock the vnode. Such pages
could then end up being flushed by uvn_flush() which already has
acquired the vnode lock. Since such pages are flagged as busy,
uvn_flush() will wait for them to be flagged as not busy. This will
never happens as uvn_io() cannot make progress until the vnode lock is
released.

Instead, grab the vnode lock before allocating and flagging pages as
busy in uvn_get(). This does extend the scope in uvn_get() in which the
vnode is locked but resolves the deadlock.

ok mpi@

Reported-by: syzbot+e63407b35dff08dbee02@syzkaller.appspotmail.com

Revert the fix for the deadlock between uvn_io() and uvn_flush().

This fix (ab)use the vnode lock to serialize access to some fields of
the corresponding pages associated with UVM vnode object and this will
create new deadlocks with the introduction of a per-uobj lock.

ok anton@

Fix a deadlock between uvn_io() and uvn_flush(). While faulting on a
page backed by a vnode, uvn_io() will end up being called in order to
populate newly allocated pages using I/O on the backing vnode. Before
performing the I/O, newly allocated pages are flagged as busy by
uvn_get(), that is before uvn_io() tries to lock the vnode. Such pages
could then end up being flushed by uvn_flush() which already has
acquired the vnode lock. Since such pages are flagged as busy,
uvn_flush() will wait for them to be flagged as not busy. This will
never happens as uvn_io() cannot make progress until the vnode lock is
released.

Instead, grab the vnode lock before allocating and flagging pages as
busy in uvn_get(). This does extend the scope in uvn_get() in which the
vnode is locked but resolves the deadlock.

ok mpi@

Reported-by: syzbot+e63407b35dff08dbee02@syzkaller.appspotmail.com

primary change: move uvm_vnode out of vnode, keeping only a pointer.
objective: vnode.h doesn't include uvm_extern.h anymore.
followup changes: include uvm_extern.h or lock.h where necessary.
ok and help from deraadt

delete a #ifdef _KERNEL chunk protecting userland from an #if 0 chunk

First round of __P removal in sys

UBC was a disaster. It worked very good when it worked, but on some
machines or some configurations or in some phase of the moon (we actually
don't know when or why) files disappeared. Since we've not been able to
track down the problem in two weeks intense debugging and we need -current
to be stable, back out everything to a state it had before UBC.

We apologise for the inconvenience.

Merge in struct uvm_vnode into struct vnode.

Merge in the unified buffer cache code as found in NetBSD 2001/03/10. The
code is written mostly by Chuck Silvers <chuq@chuq.com>/<chs@netbsd.org>.

Tested for the past few weeks by many developers, should be in a pretty stable
state, but will require optimizations and additional cleanups.

Add a new type voff_t (right now it's typedefed as off_t) used for offsets
into objects.

Gives the possibilty to mmap beyond the size of vaddr_t.

From NetBSD.

Sync style, typo, and comments a little closer to NetBSD. art@ ok

Protect protypes, certain macros, and inlines from userland. Checked userland
with a 'make build'. From NetBSD. art@ ok

$OpenBSD$

Fix the NetBSD id strings.

branches: 1.3.4;
sync with NetBSD from 1999.05.24 (there is a reason for this date)
Mostly cleanups, but also a few improvements to pagedaemon for better
handling of low memory and/or low swap conditions.

add OpenBSD tags

Import of uvm from NetBSD. Some local changes, some code disabled

Get rid of the extra vnode reference known as UVM_VNODE_CANPERSIST.

Back in the 4.4BSD days the VM subystem had a OBJ_CANPERSIST flag to
enter objects in a global cached list. Some of this logic seem to have
been copied to UVM but without the global list.

Unfortunately keeping UVM vnode objects alive after munmap(2)ing the
corresponding region without incrementing the reference count of the
related vnode led to many bugs when the vnode was recycled and/or when
it data where written back to disk (via the page daemon).

The problem is that VM pages might have a non-accounted reference to a
vnode via `pg->uobject'.

Fix "vref used where vget required" panic reported by bluhm@, gkoehler@
and Andrew Krasavinseen on bugs@.

Thanks a lot to semarie@ for co-debugging this issue!

Tested by bluhm@, tb@, miod@.

ok kettenis@, semarie@

Revert the fix for the deadlock between uvn_io() and uvn_flush().

This fix (ab)use the vnode lock to serialize access to some fields of
the corresponding pages associated with UVM vnode object and this will
create new deadlocks with the introduction of a per-uobj lock.

ok anton@

Bring back previous fix for UVM vnode deadlock.

tb@ reports that refaulting when there's contention on the vnode makes
firefox start very slowly on his machine. To revisit when the fault
handler will be unlocked.

ok anton@

Original commit message:

Fix a deadlock between uvn_io() and uvn_flush(). While faulting on a
page backed by a vnode, uvn_io() will end up being called in order to
populate newly allocated pages using I/O on the backing vnode. Before
performing the I/O, newly allocated pages are flagged as busy by
uvn_get(), that is before uvn_io() tries to lock the vnode. Such pages
could then end up being flushed by uvn_flush() which already has
acquired the vnode lock. Since such pages are flagged as busy,
uvn_flush() will wait for them to be flagged as not busy. This will
never happens as uvn_io() cannot make progress until the vnode lock is
released.

Instead, grab the vnode lock before allocating and flagging pages as
busy in uvn_get(). This does extend the scope in uvn_get() in which the
vnode is locked but resolves the deadlock.

ok mpi@

Reported-by: syzbot+e63407b35dff08dbee02@syzkaller.appspotmail.com

Revert the fix for the deadlock between uvn_io() and uvn_flush().

This fix (ab)use the vnode lock to serialize access to some fields of
the corresponding pages associated with UVM vnode object and this will
create new deadlocks with the introduction of a per-uobj lock.

ok anton@

Fix a deadlock between uvn_io() and uvn_flush(). While faulting on a
page backed by a vnode, uvn_io() will end up being called in order to
populate newly allocated pages using I/O on the backing vnode. Before
performing the I/O, newly allocated pages are flagged as busy by
uvn_get(), that is before uvn_io() tries to lock the vnode. Such pages
could then end up being flushed by uvn_flush() which already has
acquired the vnode lock. Since such pages are flagged as busy,
uvn_flush() will wait for them to be flagged as not busy. This will
never happens as uvn_io() cannot make progress until the vnode lock is
released.

Instead, grab the vnode lock before allocating and flagging pages as
busy in uvn_get(). This does extend the scope in uvn_get() in which the
vnode is locked but resolves the deadlock.

ok mpi@

Reported-by: syzbot+e63407b35dff08dbee02@syzkaller.appspotmail.com

primary change: move uvm_vnode out of vnode, keeping only a pointer.
objective: vnode.h doesn't include uvm_extern.h anymore.
followup changes: include uvm_extern.h or lock.h where necessary.
ok and help from deraadt

delete a #ifdef _KERNEL chunk protecting userland from an #if 0 chunk

First round of __P removal in sys

UBC was a disaster. It worked very good when it worked, but on some
machines or some configurations or in some phase of the moon (we actually
don't know when or why) files disappeared. Since we've not been able to
track down the problem in two weeks intense debugging and we need -current
to be stable, back out everything to a state it had before UBC.

We apologise for the inconvenience.

Merge in struct uvm_vnode into struct vnode.

Merge in the unified buffer cache code as found in NetBSD 2001/03/10. The
code is written mostly by Chuck Silvers <chuq@chuq.com>/<chs@netbsd.org>.

Tested for the past few weeks by many developers, should be in a pretty stable
state, but will require optimizations and additional cleanups.

Add a new type voff_t (right now it's typedefed as off_t) used for offsets
into objects.

Gives the possibilty to mmap beyond the size of vaddr_t.

From NetBSD.

Sync style, typo, and comments a little closer to NetBSD. art@ ok

Protect protypes, certain macros, and inlines from userland. Checked userland
with a 'make build'. From NetBSD. art@ ok

$OpenBSD$

Fix the NetBSD id strings.

branches: 1.3.4;
sync with NetBSD from 1999.05.24 (there is a reason for this date)
Mostly cleanups, but also a few improvements to pagedaemon for better
handling of low memory and/or low swap conditions.

add OpenBSD tags

Import of uvm from NetBSD. Some local changes, some code disabled

Revert the fix for the deadlock between uvn_io() and uvn_flush().

This fix (ab)use the vnode lock to serialize access to some fields of
the corresponding pages associated with UVM vnode object and this will
create new deadlocks with the introduction of a per-uobj lock.

ok anton@

Bring back previous fix for UVM vnode deadlock.

tb@ reports that refaulting when there's contention on the vnode makes
firefox start very slowly on his machine. To revisit when the fault
handler will be unlocked.

ok anton@

Original commit message:

Fix a deadlock between uvn_io() and uvn_flush(). While faulting on a
page backed by a vnode, uvn_io() will end up being called in order to
populate newly allocated pages using I/O on the backing vnode. Before
performing the I/O, newly allocated pages are flagged as busy by
uvn_get(), that is before uvn_io() tries to lock the vnode. Such pages
could then end up being flushed by uvn_flush() which already has
acquired the vnode lock. Since such pages are flagged as busy,
uvn_flush() will wait for them to be flagged as not busy. This will
never happens as uvn_io() cannot make progress until the vnode lock is
released.

Instead, grab the vnode lock before allocating and flagging pages as
busy in uvn_get(). This does extend the scope in uvn_get() in which the
vnode is locked but resolves the deadlock.

ok mpi@

Reported-by: syzbot+e63407b35dff08dbee02@syzkaller.appspotmail.com

Revert the fix for the deadlock between uvn_io() and uvn_flush().

This fix (ab)use the vnode lock to serialize access to some fields of
the corresponding pages associated with UVM vnode object and this will
create new deadlocks with the introduction of a per-uobj lock.

ok anton@

Fix a deadlock between uvn_io() and uvn_flush(). While faulting on a
page backed by a vnode, uvn_io() will end up being called in order to
populate newly allocated pages using I/O on the backing vnode. Before
performing the I/O, newly allocated pages are flagged as busy by
uvn_get(), that is before uvn_io() tries to lock the vnode. Such pages
could then end up being flushed by uvn_flush() which already has
acquired the vnode lock. Since such pages are flagged as busy,
uvn_flush() will wait for them to be flagged as not busy. This will
never happens as uvn_io() cannot make progress until the vnode lock is
released.

Instead, grab the vnode lock before allocating and flagging pages as
busy in uvn_get(). This does extend the scope in uvn_get() in which the
vnode is locked but resolves the deadlock.

ok mpi@

Reported-by: syzbot+e63407b35dff08dbee02@syzkaller.appspotmail.com

primary change: move uvm_vnode out of vnode, keeping only a pointer.
objective: vnode.h doesn't include uvm_extern.h anymore.
followup changes: include uvm_extern.h or lock.h where necessary.
ok and help from deraadt

delete a #ifdef _KERNEL chunk protecting userland from an #if 0 chunk

First round of __P removal in sys

UBC was a disaster. It worked very good when it worked, but on some
machines or some configurations or in some phase of the moon (we actually
don't know when or why) files disappeared. Since we've not been able to
track down the problem in two weeks intense debugging and we need -current
to be stable, back out everything to a state it had before UBC.

We apologise for the inconvenience.

Merge in struct uvm_vnode into struct vnode.

Merge in the unified buffer cache code as found in NetBSD 2001/03/10. The
code is written mostly by Chuck Silvers <chuq@chuq.com>/<chs@netbsd.org>.

Tested for the past few weeks by many developers, should be in a pretty stable
state, but will require optimizations and additional cleanups.

Add a new type voff_t (right now it's typedefed as off_t) used for offsets
into objects.

Gives the possibilty to mmap beyond the size of vaddr_t.

From NetBSD.

Sync style, typo, and comments a little closer to NetBSD. art@ ok

Protect protypes, certain macros, and inlines from userland. Checked userland
with a 'make build'. From NetBSD. art@ ok

$OpenBSD$

Fix the NetBSD id strings.

branches: 1.3.4;
sync with NetBSD from 1999.05.24 (there is a reason for this date)
Mostly cleanups, but also a few improvements to pagedaemon for better
handling of low memory and/or low swap conditions.

add OpenBSD tags

Import of uvm from NetBSD. Some local changes, some code disabled

Bring back previous fix for UVM vnode deadlock.

tb@ reports that refaulting when there's contention on the vnode makes
firefox start very slowly on his machine. To revisit when the fault
handler will be unlocked.

ok anton@

Original commit message:

Fix a deadlock between uvn_io() and uvn_flush(). While faulting on a
page backed by a vnode, uvn_io() will end up being called in order to
populate newly allocated pages using I/O on the backing vnode. Before
performing the I/O, newly allocated pages are flagged as busy by
uvn_get(), that is before uvn_io() tries to lock the vnode. Such pages
could then end up being flushed by uvn_flush() which already has
acquired the vnode lock. Since such pages are flagged as busy,
uvn_flush() will wait for them to be flagged as not busy. This will
never happens as uvn_io() cannot make progress until the vnode lock is
released.

Instead, grab the vnode lock before allocating and flagging pages as
busy in uvn_get(). This does extend the scope in uvn_get() in which the
vnode is locked but resolves the deadlock.

ok mpi@

Reported-by: syzbot+e63407b35dff08dbee02@syzkaller.appspotmail.com

Revert the fix for the deadlock between uvn_io() and uvn_flush().

This fix (ab)use the vnode lock to serialize access to some fields of
the corresponding pages associated with UVM vnode object and this will
create new deadlocks with the introduction of a per-uobj lock.

ok anton@

Fix a deadlock between uvn_io() and uvn_flush(). While faulting on a
page backed by a vnode, uvn_io() will end up being called in order to
populate newly allocated pages using I/O on the backing vnode. Before
performing the I/O, newly allocated pages are flagged as busy by
uvn_get(), that is before uvn_io() tries to lock the vnode. Such pages
could then end up being flushed by uvn_flush() which already has
acquired the vnode lock. Since such pages are flagged as busy,
uvn_flush() will wait for them to be flagged as not busy. This will
never happens as uvn_io() cannot make progress until the vnode lock is
released.

Instead, grab the vnode lock before allocating and flagging pages as
busy in uvn_get(). This does extend the scope in uvn_get() in which the
vnode is locked but resolves the deadlock.

ok mpi@

Reported-by: syzbot+e63407b35dff08dbee02@syzkaller.appspotmail.com

primary change: move uvm_vnode out of vnode, keeping only a pointer.
objective: vnode.h doesn't include uvm_extern.h anymore.
followup changes: include uvm_extern.h or lock.h where necessary.
ok and help from deraadt

delete a #ifdef _KERNEL chunk protecting userland from an #if 0 chunk

First round of __P removal in sys

UBC was a disaster. It worked very good when it worked, but on some
machines or some configurations or in some phase of the moon (we actually
don't know when or why) files disappeared. Since we've not been able to
track down the problem in two weeks intense debugging and we need -current
to be stable, back out everything to a state it had before UBC.

We apologise for the inconvenience.

Merge in struct uvm_vnode into struct vnode.

Merge in the unified buffer cache code as found in NetBSD 2001/03/10. The
code is written mostly by Chuck Silvers <chuq@chuq.com>/<chs@netbsd.org>.

Tested for the past few weeks by many developers, should be in a pretty stable
state, but will require optimizations and additional cleanups.

Add a new type voff_t (right now it's typedefed as off_t) used for offsets
into objects.

Gives the possibilty to mmap beyond the size of vaddr_t.

From NetBSD.

Sync style, typo, and comments a little closer to NetBSD. art@ ok

Protect protypes, certain macros, and inlines from userland. Checked userland
with a 'make build'. From NetBSD. art@ ok

$OpenBSD$

Fix the NetBSD id strings.

branches: 1.3.4;
sync with NetBSD from 1999.05.24 (there is a reason for this date)
Mostly cleanups, but also a few improvements to pagedaemon for better
handling of low memory and/or low swap conditions.

add OpenBSD tags

Import of uvm from NetBSD. Some local changes, some code disabled

Revert the fix for the deadlock between uvn_io() and uvn_flush().

This fix (ab)use the vnode lock to serialize access to some fields of
the corresponding pages associated with UVM vnode object and this will
create new deadlocks with the introduction of a per-uobj lock.

ok anton@

Fix a deadlock between uvn_io() and uvn_flush(). While faulting on a
page backed by a vnode, uvn_io() will end up being called in order to
populate newly allocated pages using I/O on the backing vnode. Before
performing the I/O, newly allocated pages are flagged as busy by
uvn_get(), that is before uvn_io() tries to lock the vnode. Such pages
could then end up being flushed by uvn_flush() which already has
acquired the vnode lock. Since such pages are flagged as busy,
uvn_flush() will wait for them to be flagged as not busy. This will
never happens as uvn_io() cannot make progress until the vnode lock is
released.

Instead, grab the vnode lock before allocating and flagging pages as
busy in uvn_get(). This does extend the scope in uvn_get() in which the
vnode is locked but resolves the deadlock.

ok mpi@

Reported-by: syzbot+e63407b35dff08dbee02@syzkaller.appspotmail.com

primary change: move uvm_vnode out of vnode, keeping only a pointer.
objective: vnode.h doesn't include uvm_extern.h anymore.
followup changes: include uvm_extern.h or lock.h where necessary.
ok and help from deraadt

delete a #ifdef _KERNEL chunk protecting userland from an #if 0 chunk

First round of __P removal in sys

UBC was a disaster. It worked very good when it worked, but on some
machines or some configurations or in some phase of the moon (we actually
don't know when or why) files disappeared. Since we've not been able to
track down the problem in two weeks intense debugging and we need -current
to be stable, back out everything to a state it had before UBC.

We apologise for the inconvenience.

Merge in struct uvm_vnode into struct vnode.

Merge in the unified buffer cache code as found in NetBSD 2001/03/10. The
code is written mostly by Chuck Silvers <chuq@chuq.com>/<chs@netbsd.org>.

Tested for the past few weeks by many developers, should be in a pretty stable
state, but will require optimizations and additional cleanups.

Add a new type voff_t (right now it's typedefed as off_t) used for offsets
into objects.

Gives the possibilty to mmap beyond the size of vaddr_t.

From NetBSD.

Sync style, typo, and comments a little closer to NetBSD. art@ ok

Protect protypes, certain macros, and inlines from userland. Checked userland
with a 'make build'. From NetBSD. art@ ok

$OpenBSD$

Fix the NetBSD id strings.

branches: 1.3.4;
sync with NetBSD from 1999.05.24 (there is a reason for this date)
Mostly cleanups, but also a few improvements to pagedaemon for better
handling of low memory and/or low swap conditions.

add OpenBSD tags

Import of uvm from NetBSD. Some local changes, some code disabled

Fix a deadlock between uvn_io() and uvn_flush(). While faulting on a
page backed by a vnode, uvn_io() will end up being called in order to
populate newly allocated pages using I/O on the backing vnode. Before
performing the I/O, newly allocated pages are flagged as busy by
uvn_get(), that is before uvn_io() tries to lock the vnode. Such pages
could then end up being flushed by uvn_flush() which already has
acquired the vnode lock. Since such pages are flagged as busy,
uvn_flush() will wait for them to be flagged as not busy. This will
never happens as uvn_io() cannot make progress until the vnode lock is
released.

Instead, grab the vnode lock before allocating and flagging pages as
busy in uvn_get(). This does extend the scope in uvn_get() in which the
vnode is locked but resolves the deadlock.

ok mpi@

Reported-by: syzbot+e63407b35dff08dbee02@syzkaller.appspotmail.com

primary change: move uvm_vnode out of vnode, keeping only a pointer.
objective: vnode.h doesn't include uvm_extern.h anymore.
followup changes: include uvm_extern.h or lock.h where necessary.
ok and help from deraadt

delete a #ifdef _KERNEL chunk protecting userland from an #if 0 chunk

First round of __P removal in sys

UBC was a disaster. It worked very good when it worked, but on some
machines or some configurations or in some phase of the moon (we actually
don't know when or why) files disappeared. Since we've not been able to
track down the problem in two weeks intense debugging and we need -current
to be stable, back out everything to a state it had before UBC.

We apologise for the inconvenience.

Merge in struct uvm_vnode into struct vnode.

Merge in the unified buffer cache code as found in NetBSD 2001/03/10. The
code is written mostly by Chuck Silvers <chuq@chuq.com>/<chs@netbsd.org>.

Tested for the past few weeks by many developers, should be in a pretty stable
state, but will require optimizations and additional cleanups.

Add a new type voff_t (right now it's typedefed as off_t) used for offsets
into objects.

Gives the possibilty to mmap beyond the size of vaddr_t.

From NetBSD.

Sync style, typo, and comments a little closer to NetBSD. art@ ok

Protect protypes, certain macros, and inlines from userland. Checked userland
with a 'make build'. From NetBSD. art@ ok

$OpenBSD$

Fix the NetBSD id strings.

branches: 1.3.4;
sync with NetBSD from 1999.05.24 (there is a reason for this date)
Mostly cleanups, but also a few improvements to pagedaemon for better
handling of low memory and/or low swap conditions.

add OpenBSD tags

Import of uvm from NetBSD. Some local changes, some code disabled

primary change: move uvm_vnode out of vnode, keeping only a pointer.
objective: vnode.h doesn't include uvm_extern.h anymore.
followup changes: include uvm_extern.h or lock.h where necessary.
ok and help from deraadt

delete a #ifdef _KERNEL chunk protecting userland from an #if 0 chunk

First round of __P removal in sys

UBC was a disaster. It worked very good when it worked, but on some
machines or some configurations or in some phase of the moon (we actually
don't know when or why) files disappeared. Since we've not been able to
track down the problem in two weeks intense debugging and we need -current
to be stable, back out everything to a state it had before UBC.

We apologise for the inconvenience.

Merge in struct uvm_vnode into struct vnode.

Merge in the unified buffer cache code as found in NetBSD 2001/03/10. The
code is written mostly by Chuck Silvers <chuq@chuq.com>/<chs@netbsd.org>.

Tested for the past few weeks by many developers, should be in a pretty stable
state, but will require optimizations and additional cleanups.

Add a new type voff_t (right now it's typedefed as off_t) used for offsets
into objects.

Gives the possibilty to mmap beyond the size of vaddr_t.

From NetBSD.

Sync style, typo, and comments a little closer to NetBSD. art@ ok

Protect protypes, certain macros, and inlines from userland. Checked userland
with a 'make build'. From NetBSD. art@ ok

$OpenBSD$

Fix the NetBSD id strings.

branches: 1.3.4;
sync with NetBSD from 1999.05.24 (there is a reason for this date)
Mostly cleanups, but also a few improvements to pagedaemon for better
handling of low memory and/or low swap conditions.

add OpenBSD tags

Import of uvm from NetBSD. Some local changes, some code disabled