Merge ^/head r308870 through r309105.

Release laundered vnode pages to the head of the inactive queue.

The swap pager enqueues laundered pages near the head of the inactive queue
to avoid another trip through LRU before reclamation. Thi

Release laundered vnode pages to the head of the inactive queue.

The swap pager enqueues laundered pages near the head of the inactive queue
to avoid another trip through LRU before reclamation. This change adds
support for this behaviour to the vnode pager and makes use of it in UFS and
ext2fs. Some ioflag handling is consolidated into a common subroutine so
that this support can be easily extended to other filesystems which make use
of the buffer cache. No changes are needed for ZFS since its putpages
routine always undirties the pages before returning, and the laundry
thread requeues the pages appropriately in this case.

Reviewed by: alc, kib
Differential Revision: https://reviews.freebsd.org/D8589

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Restore vnode pager statistic for buffer pagers.

Reviewed by: alc, markj
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D8585

Merge ^/head r308491 through r308841.

[mips] enable relbuf on mips for now to work around page aliasing in mips hardware.

Although the higher end MIPS hardware handles cache aliasing issues in
hardware, the older cores (r4k, etc) and so

[mips] enable relbuf on mips for now to work around page aliasing in mips hardware.

Although the higher end MIPS hardware handles cache aliasing issues in
hardware, the older cores (r4k, etc) and some compile versions of the
newer cores (mips24k, mips34k, mips74k) don't have this feature.
This means we end up with some very unfortunate behaviour that was
made very obvious by some recent changes to the FFS pager by kib.

So, flip this off until we get our MIPS pmap/cache code upgraded to
handle aliased pages in software.

Discussed with: kib, bsdimp, juli

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Merge ^/head r308227 through r308490.

Tweaks for the buffer pager.

Pass current thread credentials instead of NOCRED.
Only allow unmapped buffers for filesystem which proclaimed the support.

For all filesystems which currently use buff

Tweaks for the buffer pager.

Pass current thread credentials instead of NOCRED.
Only allow unmapped buffers for filesystem which proclaimed the support.

For all filesystems which currently use buffer pager (UFS, msdosfs and
cd9660), the changes are effectively nop.

Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

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Merge ^/head r303250 through r308226.

Add BUF_TRACKING and FULL_BUF_TRACKING buffer debugging

Upstream the BUF_TRACKING and FULL_BUF_TRACKING buffer debugging code.
This can be handy in tracking down what code touched hung bios and bufs

Add BUF_TRACKING and FULL_BUF_TRACKING buffer debugging

Upstream the BUF_TRACKING and FULL_BUF_TRACKING buffer debugging code.
This can be handy in tracking down what code touched hung bios and bufs
last. The full history is especially useful, but adds enough bloat that
it shouldn't be enabled in release builds.

Function names (or arbitrary string constants) are tracked in a
fixed-size ring in bufs. Bios gain a pointer to the upper buf for
tracking. SCSI CCBs gain a pointer to the upper bio for tracking.

Reviewed by: markj
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D8366

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Merge ^/head r307736 through r308146.

Generalize UFS buffer pager to allow it serving other filesystems
which also use buffer cache.

Most important addition to the code is the handling of filesystems
where the block size is less than th

Generalize UFS buffer pager to allow it serving other filesystems
which also use buffer cache.

Most important addition to the code is the handling of filesystems
where the block size is less than the machine page size, which might
require reading several buffers to validate single page.

Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks

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Merge ^/head r306906 through r307382.

Fix a race in vm_page_busy_sleep(9).

Suppose that we have an exclusively busy page, and a thread which can
accept shared-busy page. In this case, typical code waiting for the
page xbusy state to pa

Fix a race in vm_page_busy_sleep(9).

Suppose that we have an exclusively busy page, and a thread which can
accept shared-busy page. In this case, typical code waiting for the
page xbusy state to pass is
again:
VM_OBJECT_WLOCK(object);
...
if (vm_page_xbusied(m)) {
vm_page_lock(m);
VM_OBJECT_WUNLOCK(object); <---1
vm_page_busy_sleep(p, "vmopax");
goto again;
}

Suppose that the xbusy state owner locked the object, unbusied the
page and unlocked the object after we are at the line [1], but before we
executed the load of the busy_lock word in vm_page_busy_sleep(). If it
happens that there is still no waiters recorded for the busy state,
the xbusy owner did not acquired the page lock, so it proceeded.

More, suppose that some other thread happen to share-busy the page
after xbusy state was relinquished but before the m->busy_lock is read
in vm_page_busy_sleep(). Again, that thread only needs vm_object lock
to proceed. Then, vm_page_busy_sleep() reads busy_lock value equal to
the VPB_SHARERS_WORD(1).

In this case, all tests in vm_page_busy_sleep(9) pass and we are going
to sleep, despite the page being share-busied.

Update check for m->busy_lock == VPB_UNBUSIED in vm_page_busy_sleep(9)
to also accept shared-busy state if we only wait for the xbusy state to
pass.

Merge sequential if()s with the same 'then' clause in
vm_page_busy_sleep().

Note that the current code does not share-busy pages from parallel
threads, the only way to have more that one sbusy owner is right now
is to recurse.

Reported and tested by: pho (previous version)
Reviewed by: alc, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D8196

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Merge ^/head r306412 through r306905.

vfs_bio: Remove a leading space (style)

Introduced in r282085.

Sponsored by: Dell EMC Isilon

vfs: remove the __bo_vnode field from struct vnode

The pointer can be obtained using __containerof instead.

Reviewed by: kib

Merge ^/head r303250 through r304235.

MFhead @ r304038

Remove b_pin_count from struct buf.

It was added in r153192 for XFS and doesn't appear to have been used for
anything else. XFS was disconnected in r241607 and removed entirely in
r247631.

Reported

Remove b_pin_count from struct buf.

It was added in r153192 for XFS and doesn't appear to have been used for
anything else. XFS was disconnected in r241607 and removed entirely in
r247631.

Reported by: mlaier
Reviewed by: imp, kib
Differential Revision: https://reviews.freebsd.org/D7468

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Let DDB's buf printer handle NULL pointers in the buf page array.

A buf's b_pages and b_npages fields may be inconsistent after a panic.
For instance, vfs_vmio_invalidate() sets b_npages to zero onl

Let DDB's buf printer handle NULL pointers in the buf page array.

A buf's b_pages and b_npages fields may be inconsistent after a panic.
For instance, vfs_vmio_invalidate() sets b_npages to zero only after all
pages are unwired and their page array entries are cleared.

MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division

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sys/kern: spelling fixes.

Mostly on comments but affects some debug messages.

MFC after: 2 weeks

bufs: make B_DIRTY and B_PERSISTENT flags available

It appears these flags were related to ext2fs but are completely
unused nowadays. Retire them.

Suggested by: mckusick

sys: use our roundup2/rounddown2() macros when param.h is available.

rounddown2 tends to produce longer lines than the original code
and when the code has a high indentation level it was not really

sys: use our roundup2/rounddown2() macros when param.h is available.

rounddown2 tends to produce longer lines than the original code
and when the code has a high indentation level it was not really
advantageous to do the replacement.

This tries to strike a balance between readability using the macros
and flexibility of having the expressions, so not everything is
converted.

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MFH

Sponsored by: The FreeBSD Foundation

Add four new RCTL resources - readbps, readiops, writebps and writeiops,
for limiting disk (actually filesystem) IO.

Note that in some cases these limits are not quite precise. It's ok,
as long as i

Add four new RCTL resources - readbps, readiops, writebps and writeiops,
for limiting disk (actually filesystem) IO.

Note that in some cases these limits are not quite precise. It's ok,
as long as it's within some reasonable bounds.

Testing - and review of the code, in particular the VFS and VM parts - is
very welcome.

MFC after: 1 month
Relnotes: yes
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D5080

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