CVS log for src/sys/kern/vfs_bio.c

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Keyword substitution: kv
Default branch: MAIN

Revert "kern: Sprinkle biglock-slippage assertions."

Got the diagnostic information I needed from this, and it's holding
up releng tests of everything else, so let's back this out until I
need more diagnostics or track down the original source of the
problem.

kern: Sprinkle biglock-slippage assertions.

We seem to have a poltergeist that occasionally messes with the
biglock depth, but it's very hard to reproduce and only manifests as
some other CPU spinning out on the kernel lock which is no good for
diagnostics.

Sync with HEAD.

If we're only doing a count-only kern.buf sysctl, just return the number
of active members in the pool cache (plus some slop) instead of looking
in all the free buffer list.  Should reduce CPU usage for "systat vm"
to << 1% especially for machines with a larger number of buffers.

Expose KERN_BUFSLOP in <sys/sysctl.h>.

Pad out the slop for kern.buf based on the passed in element size,
rather than a size of an unrelated struct.

Sync with HEAD.

Sync with HEAD.

Add a sysctl hashstat collector for bufhash.

fix the UFS2 extattr truncate code to play nice with wapbl.
also, rather than pull in the FreeBSD V_NORMAL/V_ALT flags to
vinvalbuf() and the buf b_xflags field and BX_ALTDATA flag,
add a binvalbuf() function to invalid a specific buffer
and use that to invalidate the two possible exattr bufs
during IO_EXT truncations.

uvm_availmem(): give it a boolean argument to specify whether a recent
cached value will do, or if the very latest total must be fetched.  It can
be called thousands of times a second and fetching the totals impacts not
only the calling LWP but other CPUs doing unrelated activity in the VM
system.

pass B_PHYS|B_RAW also in nestio_setup(), courtesy to e.g. xbd(4), which
wants to know whether the buf came from user space or bio subsystem

Sync with bouyer-xenpvh-base2 (HEAD)

Sync with HEAD

Rename buf_syncwait() to vfs_syncwait(), and have it wait on v_numoutput
rather than BC_BUSY.  Removes the dependency on bufhash.

Sync with HEAD

Mostly merge changes from HEAD upto 20200411

for bmempools set align, not ioff

explicitly use DEV_BSIZE align for all bmempools

this is required for Xen xbd(4) in order to not have to use bounce buffers

the alignment is implicitly provided when POOL_REDZONE is not active,
this change makes it also aligned when POOL_REDZONE _is_ active - that is
when (!KMSAN && (DIAGNOSTIC || KASAN))

Remove buffer reference counting, now that it's safe to destroy b_busy after
waking any waiters.

Merge changes from current as of 20200406

- Hide the details of SPCF_SHOULDYIELD and related behind a couple of small
  functions: preempt_point() and preempt_needed().

- preempt(): if the LWP has exceeded its timeslice in kernel, strip it of
  any priority boost gained earlier from blocking.

Sync with head.

OOPS -- fix mistake in previous commit.

bbusy really needs to return the error; otherwise things are very
bad!

Buffer cache SDT probes.

Sync with head.

biodone2(): don't acquire kernel_lock for anybody anymore.

Rename uvm_free() -> uvm_availmem().

s/transfered/transferred/

uvmexp.free -> uvm_free()

Add a comment.

For safety, cv_broadcast(&bp->b_busy) in more places where the buffer is
changing identity or moving from one vnode list to another.

Adjustment to previous: if we're going to toss the buffer, then wake
everybody.

- Avoid thundering herd: cv_broadcast(&bp->b_busy) -> cv_signal(&bp->b_busy)
- Sprinkle __cacheline_aligned.

 Change buf_nbuf()'s return value from int to u_int to avoid undefined
behavior in wapbl_start() which extended int to size_t.

Error message was:
> UBSan: Undefined Behavior in ../../../../kern/vfs_wapbl.c:609:41, signed integer overflow: 3345138 * 1024 cannot be represented in type 'int'

>        /* XXX maybe use filesystem fragment size instead of 1024 */
>         /* XXX fix actual number of buffers reserved per filesystem. */
>         wl->wl_bufcount_max = (buf_nbuf() / 2) * 1024;

Need more work?

Sync with HEAD

Sync with HEAD, resolve a couple of conflicts

Fix kernel pointer leaks in sysctl_dobuf. While here constify argument.

Also memset the buffer, to prevent leaks (even if there doesn't seem to
be currently).

Sync with HEAD

Resolve a couple of conflicts (result of the uimin/uimax changes)

Pull up following revision(s) (requested by hannken in ticket #1000):

	sys/kern/vfs_bio.c: revision 1.277

Make sure getnewbuf() runs bawrite() inside fstrans.

Use fstrans_start_nowait() to skip buffers that would block.

Make sure getnewbuf() runs bawrite() inside fstrans.
Use fstrans_start_nowait() to skip buffers that would block.

update from HEAD

Pull up following revision(s) (requested by pgoyette in ticket #335):
	share/man/man9/kernhist.9: 1.5-1.8
	sys/arch/acorn26/acorn26/pmap.c: 1.39
	sys/arch/arm/arm32/fault.c: 1.105 via patch
	sys/arch/arm/arm32/pmap.c: 1.350, 1.359
	sys/arch/arm/broadcom/bcm2835_bsc.c: 1.7
	sys/arch/arm/omap/if_cpsw.c: 1.20
	sys/arch/arm/omap/tiotg.c: 1.7
	sys/arch/evbarm/conf/RPI2_INSTALL: 1.3
	sys/dev/ic/sl811hs.c: 1.98
	sys/dev/usb/ehci.c: 1.256
	sys/dev/usb/if_axe.c: 1.83
	sys/dev/usb/motg.c: 1.18
	sys/dev/usb/ohci.c: 1.274
	sys/dev/usb/ucom.c: 1.119
	sys/dev/usb/uhci.c: 1.277
	sys/dev/usb/uhub.c: 1.137
	sys/dev/usb/umass.c: 1.160-1.162
	sys/dev/usb/umass_quirks.c: 1.100
	sys/dev/usb/umass_scsipi.c: 1.55
	sys/dev/usb/usb.c: 1.168
	sys/dev/usb/usb_mem.c: 1.70
	sys/dev/usb/usb_subr.c: 1.221
	sys/dev/usb/usbdi.c: 1.175
	sys/dev/usb/usbdi_util.c: 1.67-1.70
	sys/dev/usb/usbroothub.c: 1.3
	sys/dev/usb/xhci.c: 1.75
	sys/external/bsd/drm2/dist/drm/i915/i915_gem.c: 1.34
	sys/kern/kern_history.c: 1.15
	sys/kern/kern_xxx.c: 1.74
	sys/kern/vfs_bio.c: 1.275-1.276
	sys/miscfs/genfs/genfs_io.c: 1.71
	sys/sys/kernhist.h: 1.21
	sys/ufs/ffs/ffs_balloc.c: 1.63
	sys/ufs/lfs/lfs_vfsops.c: 1.361
	sys/ufs/lfs/ulfs_inode.c: 1.21
	sys/ufs/lfs/ulfs_vnops.c: 1.52
	sys/ufs/ufs/ufs_inode.c: 1.102
	sys/ufs/ufs/ufs_vnops.c: 1.239
	sys/uvm/pmap/pmap.c: 1.37-1.39
	sys/uvm/pmap/pmap_tlb.c: 1.22
	sys/uvm/uvm_amap.c: 1.108
	sys/uvm/uvm_anon.c: 1.64
	sys/uvm/uvm_aobj.c: 1.126
	sys/uvm/uvm_bio.c: 1.91
	sys/uvm/uvm_device.c: 1.66
	sys/uvm/uvm_fault.c: 1.201
	sys/uvm/uvm_km.c: 1.144
	sys/uvm/uvm_loan.c: 1.85
	sys/uvm/uvm_map.c: 1.353
	sys/uvm/uvm_page.c: 1.194
	sys/uvm/uvm_pager.c: 1.111
	sys/uvm/uvm_pdaemon.c: 1.109
	sys/uvm/uvm_swap.c: 1.175
	sys/uvm/uvm_vnode.c: 1.103
	usr.bin/vmstat/vmstat.c: 1.219
Reorder to test for null before null deref in debug code
--
Reorder to test for null before null deref in debug code
--
KNF
--
No need for '\n' in UVMHIST_LOG
--
normalise a BIOHIST log message
--
Update the kernhist(9) kernel history code to address issues identified
in PR kern/52639, as well as some general cleaning-up...
(As proposed on tech-kern@ with additional changes and enhancements.)
Details of changes:
* All history arguments are now stored as uintmax_t values[1], both in
   the kernel and in the structures used for exporting the history data
   to userland via sysctl(9).  This avoids problems on some architectures
   where passing a 64-bit (or larger) value to printf(3) can cause it to
   process the value as multiple arguments.  (This can be particularly
   problematic when printf()'s format string is not a literal, since in
   that case the compiler cannot know how large each argument should be.)
* Update the data structures used for exporting kernel history data to
   include a version number as well as the length of history arguments.
* All [2] existing users of kernhist(9) have had their format strings
   updated.  Each format specifier now includes an explicit length
   modifier 'j' to refer to numeric values of the size of uintmax_t.
* All [2] existing users of kernhist(9) have had their format strings
   updated to replace uses of "%p" with "%#jx", and the pointer
   arguments are now cast to (uintptr_t) before being subsequently cast
   to (uintmax_t).  This is needed to avoid compiler warnings about
   casting "pointer to integer of a different size."
* All [2] existing users of kernhist(9) have had instances of "%s" or
   "%c" format strings replaced with numeric formats; several instances
   of mis-match between format string and argument list have been fixed.
* vmstat(1) has been modified to handle the new size of arguments in the
   history data as exported by sysctl(9).
* vmstat(1) now provides a warning message if the history requested with
   the -u option does not exist (previously, this condition was silently
   ignored, with only a single blank line being printed).
* vmstat(1) now checks the version and argument length included in the
   data exported via sysctl(9) and exits if they do not match the values
   with which vmstat was built.
* The kernhist(9) man-page has been updated to note the additional
   requirements imposed on the format strings, along with several other
   minor changes and enhancements.
[1] It would have been possible to use an explicit length (for example,
     uint64_t) for the history arguments.  But that would require another
     "rototill" of all the users in the future when we add support for an
     architecture that supports a larger size.  Also, the printf(3)
format
     specifiers for explicitly-sized values, such as "%"PRIu64, are much
     more verbose (and less aesthetically appealing, IMHO) than simply
     using "%ju".
[2] I've tried very hard to find "all [the] existing users of
kernhist(9)"
     but it is possible that I've missed some of them.  I would be glad
to
     update any stragglers that anyone identifies.
--
For some reason this single kernel seems to have outgrown its declared
size as a result of the kernhist(9) changes.  Bump the size.
XXX The amount of increase may be excessive - anyone with more detailed
XXX knowledge please feel free to further adjust the value
appropriately.
--
Misssed one cast of pointer --> uintptr_t in previous kernhist(9) commit
--
And yet another one.  :(
--
Use correct mark-up for NetBSD version.
--
More improvements in grammar and readability.
--
Remove a stray '"' (obvious typo) and add a couple of casts that are
probably needed.
--
And replace an instance of "%p" conversion with "%#jx"
--
Whitespace fix. Give Bl tag table a width. Fix Xr.

Update the kernhist(9) kernel history code to address issues identified
in PR kern/52639, as well as some general cleaning-up...

(As proposed on tech-kern@ with additional changes and enhancements.)

Details of changes:

* All history arguments are now stored as uintmax_t values[1], both in
  the kernel and in the structures used for exporting the history data
  to userland via sysctl(9).  This avoids problems on some architectures
  where passing a 64-bit (or larger) value to printf(3) can cause it to
  process the value as multiple arguments.  (This can be particularly
  problematic when printf()'s format string is not a literal, since in
  that case the compiler cannot know how large each argument should be.)

* Update the data structures used for exporting kernel history data to
  include a version number as well as the length of history arguments.

* All [2] existing users of kernhist(9) have had their format strings
  updated.  Each format specifier now includes an explicit length
  modifier 'j' to refer to numeric values of the size of uintmax_t.

* All [2] existing users of kernhist(9) have had their format strings
  updated to replace uses of "%p" with "%#jx", and the pointer
  arguments are now cast to (uintptr_t) before being subsequently cast
  to (uintmax_t).  This is needed to avoid compiler warnings about
  casting "pointer to integer of a different size."

* All [2] existing users of kernhist(9) have had instances of "%s" or
  "%c" format strings replaced with numeric formats; several instances
  of mis-match between format string and argument list have been fixed.

* vmstat(1) has been modified to handle the new size of arguments in the
  history data as exported by sysctl(9).

* vmstat(1) now provides a warning message if the history requested with
  the -u option does not exist (previously, this condition was silently
  ignored, with only a single blank line being printed).

* vmstat(1) now checks the version and argument length included in the
  data exported via sysctl(9) and exits if they do not match the values
  with which vmstat was built.

* The kernhist(9) man-page has been updated to note the additional
  requirements imposed on the format strings, along with several other
  minor changes and enhancements.

[1] It would have been possible to use an explicit length (for example,
    uint64_t) for the history arguments.  But that would require another
    "rototill" of all the users in the future when we add support for an
    architecture that supports a larger size.  Also, the printf(3) format
    specifiers for explicitly-sized values, such as "%"PRIu64, are much
    more verbose (and less aesthetically appealing, IMHO) than simply
    using "%ju".

[2] I've tried very hard to find "all [the] existing users of kernhist(9)"
    but it is possible that I've missed some of them.  I would be glad to
    update any stragglers that anyone identifies.

Sync with HEAD

normalise a BIOHIST log message

move some buffer cache internals declarations from buf.h to vfs_bio.c.
this is needed to avoid name conflicts with ZFS and also
makes it clearer that other code shouldn't be messing with these.
remove the LFS debug code that poked around in bufqueues and
remove the BQ_EMPTY bufqueue since nothing uses it anymore.
provide a function to let LFS and wapbl read the value of nbuf for now.

When logging a history record for biowait(), include the return address
as a parameter, to identify to which of the many calls to biowait() the
record refers.

Sync with HEAD

Sync with HEAD

expose disk device FUA/DPO support via DIOCGCACHE, and allow the flags
to be set for I/O; implement support in sd(4) and nvme(4)

discussed on tech-kern

Use brelsel while the bufcache_lock is held rather than dropping it
and re-taking / dropping it in brelse

Sync with HEAD

Nix trailing whitespace.

Sync with HEAD

Fix build

Simplify getiobuf.  buf_init already does bp->b_objlock == &buffer_lock

Sync with HEAD.  (Note that most of these changes are simply $NetBSD$
tag issues.)

Remove some extraneous whitespace

Decouple BIOHIST from other users of KERNHIST.

Fix locking so we don't release the lock between the time we check the
tailq (for being non-empty) and the time we remove an entry.

Add a BIOHIST option.  As mentioned on tech-kern.

typo in comment

Sync with HEAD

Sync with HEAD

fixup comment

Sync with HEAD

Allow sparc kernels to build with SSP by using a constant PAGE_SIZE...

Sync with HEAD

In bwrite, add assertion that vp != NULL. (vp is the vnode from the
buffer being written.)

There's some logic here that carefully checks for vp being null, and
other logic that will crash if it is. It appears that it's all
needless paranoia. See tech-kern for more info.

Unless someone sees the assertion go off (in which case a lot more
investigation is needed) I or someone will clean out the logic at some
future point.

Spotted by coypu.

Sync with HEAD

Implement the 'io' provider for DTrace.  From riastradh@, with
fixes from me.

Whatever the point of this "biodone_vfs" global function pointer is
(something rumpity?) declare it properly in a header file instead of
in secret where its types can diverge.

KASSERT->KASSERTMSG to allow debugging a double-free'd buffer in ddb.

Sync with HEAD

to garnish, dust with _KERNEL_OPT

Sync with HEAD

Remove the 'cred' argument from bread(). Remove a now unused var in
ffs_snapshot.c. Update the man page accordingly.

ok hannken@

Remove the 'cred' argument from breadn(), and update the man page
accordingly.

ok hannken@

Remove the 'cred' argument from bio_doread().

Replace random with cprng_fast32. Reorganise computation to replace
(32bit) division with (long) multiplication.

Don't next structure and enum definitions.
Don't use C++ keywords new, try, class, private, etc.

Rebase to HEAD as of a few days ago.

Rebase.

Call biodone() in the bdev_strategy() error via a pointer.  Decouples
subr_devsw from VFS -- not that I/O buffers are _VFS_ entities -- and
eliminates the last weak alias from librump, which means things now
fully work on glibc (w/o LD_DYNAMIC_WEAK) and musl.

The whole code path is suspect anyway, since nothing prevents the device
from escaping after the lookup, suggesting that the whole error path
should be handled by the caller, but oh well.

sync with head.

for a reference, the tree before this commit was tagged
as yamt-pagecache-tag8.

this commit was splitted into small chunks to avoid
a limitation of cvs.  ("Protocol error: too many arguments")

sync with head

Ensure that the top level sysctl nodes (kern, vfs, net, ...) exist before
the sysctl link sets are processed, and remove redundancy.

Shaves >13kB off of an amd64 GENERIC, not to mention >1k duplicate
lines of code.

Mark a diagnostic-only variable

Replace macro v_specmountpoint with two functions spec_node_getmountedfs()
and spec_node_setmountedfs() to manage the file system mounted on a device.
Assert the device is a block device.

Welcome to 6.99.24

Discussed on tech-kern@ some time ago.

Reviewed by: David Holland <dholland@netbsd.org>

Remove unused variable

remove useless initialization
http://m00nbsd.net/ae123a9bae03f7dde5c6d654412daf5a.html

resync from head

Redo case where buf_map is not yet mapped when buf_memcalc() is called
early from pmap_bootstrap(). Makes alpha, and probably others, boot
again.

calculate vnode cache size based on the resource it gets allocated from
this stops setting kern.maxvnodes to high so it exhausts available space in kmem

http://mail-index.netbsd.org/tech-kern/2013/03/08/msg015095.html

resync with head

sync with head

Always call brelse() on error for breadn() too.

Always call brelse() on error. Otherwise a possible error from bread() will
cause the buffer to stay lock and we end up blocking forever in
VOP_CLOSE->spec_close->vinvalbuf->bbysy since the buffer is marked busy
but there is no I/O pending.
This caused my laptop to hang on boot_findwedge because:
    findroot: unable to read block 358331527 of dev dk0 (22)

Change bread() and breadn() to never return a buffer on
error and modify all callers to not brelse() on error.

Welcome to 6.99.16

PR kern/46282 (6.0_BETA crash: msdosfs_bmap -> pcbmap -> bread -> bio_doread)

sync with head

Pull up following revision(s) (requested by dsl in ticket #1770):
	sys/kern/vfs_bio.c: revision 1.239
Fix processing of vm.bufmem_lowater and vm.bufmem_hiwater on 64bit systems.
Use CTLTYPE_LONG for bufmem_lowater and bufmem_hiwater.
Use separate temporaries for the 'int' percentage and the 'long'
  water marks.
Shows up on amd64 now that the sysctl values are marked as 64bit.
sparc64 has been badly broken for ages. Fix part of PR kern/46536

Pull up following revision(s) (requested by dsl in ticket #307):
	sys/kern/vfs_bio.c: revision 1.239
Use separate temporaries for the 'int' percentage and the 'long'
  water marks.
Previous paniced on sparc64 due to a misaligned copy.

Pull up following revision(s) (requested by dsl in ticket #306):
	sys/kern/vfs_bio.c: revision 1.238
	sys/dev/bluetooth/bcsp.c: revision 1.21
	sys/dev/acpi/asus_acpi.c: revision 1.24
	sys/miscfs/syncfs/sync_subr.c: revision 1.48
Some calls to sysctl_createv() have mismatches betwwen the data type
and the CTLTYPE_xxx flags.
Fixes bugs in sys/dev/acpi/asus_acpi.c sys/dev/bluetooth/bcsp.c
  sys/kern/vfs_bio.c sys/miscfs/syncfs/sync_subr.c
(mostly passing the address of a uint64_t when typed as CTLTYPE_INT).
The vm.bufmem_lowater (etc) sysctls needs to be processed with a
  64bit temporary value on 64bit systems.
Fixes PR kern/46536.

Use separate temporaries for the 'int' percentage and the 'long'
  water marks.
Previous paniced on sparc64 due to a misaligned copy.

Fix processing of vm.bufmem_lowater and vm.bufmem_hiwater on 64bit systems.
The values are 'u_long' so copying them into an 'int' temporary
(to avoid writing an out of range value into the actual variable)
doesn't work too well at all.
Shows up on amd64 now that the sysctl values are marked as 64bit.
sparc64 must have been badly broken for ages.

Add some pre-processor magic to verify that the type of the data item
  passed to sysctl_createv() actually matches the declared type for
  the item itself.
In the places where the caller specifies a function and a structure
  address (typically the 'softc') an explicit (void *) cast is now needed.
Fixes bugs in sys/dev/acpi/asus_acpi.c sys/dev/bluetooth/bcsp.c
  sys/kern/vfs_bio.c sys/miscfs/syncfs/sync_subr.c and setting
  AcpiGbl_EnableAmlDebugObject.
(mostly passing the address of a uint64_t when typed as CTLTYPE_INT).
I've test built quite a few kernels, but there may be some unfixed MD
  fallout. Most likely passing &char[] to char *.
Also add CTLFLAG_UNSIGNED for unsiged decimals - not set yet.

sync with head

merge to -current.

Pull up following revision(s) (requested by rmind in ticket #1718):
	sys/kern/vfs_bio.c: revision 1.233
sysctl_dobuf: re-acquire the sysctl lock on retry path.  PR/45827.

Pull up following revision(s) (requested by rmind in ticket #1718):
	sys/kern/vfs_bio.c: revision 1.233
sysctl_dobuf: re-acquire the sysctl lock on retry path.  PR/45827.

Pull up following revision(s) (requested by rmind in ticket #1718):
	sys/kern/vfs_bio.c: revision 1.233
sysctl_dobuf: re-acquire the sysctl lock on retry path.  PR/45827.

allocate uareas and buffers from kernel_map again
add code to drain pools if kmem_arena runs out of space

pool_page_alloc, pool_page_alloc_meta: avoid extra compare, use const.
ffs_mountfs,sys_swapctl: replace memset with kmem_zalloc.
sys_swapctl: move kmem_free outside the lock path.
uvm_init: fix comment, remove pointless numeration of steps.
uvm_map_enter: remove meflagval variable.
Fix some indentation.

extending vmem(9) to be able to allocated resources for it's own needs.
simplifying uvm_map handling (no special kernel entries anymore no relocking)
make malloc(9) a thin wrapper around kmem(9)
(with private interface for interrupt safety reasons)

releng@ acknowledged

sysctl_dobuf: re-acquire the sysctl lock on retry path.  PR/45827.

Make parts of this this somewhat less gross by using ilog2() from
<sys/bitops.h>.  Additionally, concoct shorter wchan names for >=1 MiB
buf pools using the irrelevantly-more-correct format specifier for u_int.

Change VOP_BWRITE() to take a vnode as its first argument like all other
VOPs do.  Layered file systems no longer have to modify bp->b_vp and run
into trouble when an async VOP_BWRITE() uses the wrong vnode.

- change all occurences of VOP_BWRITE(bp) to VOP_BWRITE(bp->b_vp, bp).
- remove layer_bwrite().
- welcome to 5.99.55

Adresses PR kern/38762 panic: vwakeup: neg numoutput

No objections from tech-kern@.

Catchup with rmind-uvmplock merge.

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.

Sync with HEAD.

sync with head

- Replace few malloc(9) uses with kmem(9).
- Rename buf_malloc() to buf_alloc(), fix comments.
- Remove some unnecessary inclusions.

sync with head

G/C count_lock_queue (unused for 12 years)

sync with head

Include internal definitions (uvm/uvm.h) only where necessary.

Fix nestio's behavior on error.

The mbp->b_resid is used to track if all the nested buffers have been issued
and reported back. When the last buffer calls in, mbp->b_resid becomes zero
and biodone(mbp) is called. This is fine as long as there are no errors.

If a read-error does occure in one of the nested buffers, the mbp->b_error is
set and on its call to biodone(mbp), with mbp->b_resid is zero, physio()
panics since it asserts that IF an error is set on a buffer, there should be a
residual amount of data left to transfered.

The patch fixes this case by setting mbp->b_resid back to mbp->b_bcount on
mbp->b_error just before biodone(mbp).

This behaviour is consistent with normal buffer issueing. It either succeeds
or doesn't succeed.

brelsel: Clear B_COWDONE flag on clean (! BO_DELWRI) buffer.  B_COWDONE is set
if the buffer was read with intention to modify but the caller changed its mind.

This error could lead to snapshot corruption when a buffer with B_COWDONE set
resides on the freelist and we create a new snapshot.

Sync with HEAD.

Don't sleep forever if hz < 25.

from Alessandro Forin

Sync with HEAD.

Change struct uvm_object::vmobjlock to be dynamically allocated with
mutex_obj_alloc().  It allows us to share the locks among UVM objects.

sync with head

fs_ffs.h is no longer required (since the death of bufops / softdep)

Add a comment saying "name" to pool_init() is never freed (fixing
requires touching pool implementation).  No biggie, though, since
the pools themselves are never freed.

Add a small comment on buffer cache locking, fix mark letter b_objlock.

G/C unused breada() and bdirty().

Excommunicate comment not abiding to the 80col dogma.
(well, turns out it was no longer valid either)

Sync with HEAD.

Commit is split, to avoid a "too many arguments" protocol error.

sync with head.

Sync with HEAD.

like KERN_FILE2: *do* update "needed" when there is no count.  we want
userland to know what sort of size to provide..

while here, slightly normalise the previous to init_sysctl.c.

Sync with HEAD.

Fix some comments.

PR kern/26878 FFSv2 + softdep = livelock (no free ram)
PR kern/16942 panic with softdep and quotas
PR kern/19565 panic: softdep_write_inodeblock: indirect pointer #1 mismatch
PR kern/26274 softdep panic: allocdirect_merge: ...
PR kern/26374 Long delay before non-root users can write to softdep partitions
PR kern/28621 1.6.x "vp != NULL" panic in ffs_softdep.c:4653 while unmounting a softdep (+quota) filesystem
PR kern/29513 FFS+Softdep panic with unfsck-able file-corruption
PR kern/31544 The ffs softdep code appears to fail to write dirty bits to disk
PR kern/31981 stopping scsi disk can cause panic (softdep)
PR kern/32116 kernel panic in softdep (assertion failure)
PR kern/32532 softdep_trackbufs deadlock
PR kern/37191 softdep: locking against myself
PR kern/40474 Kernel panic after remounting raid root with softdep

Retire softdep, pass 2. As discussed and later formally announced on the
mailing lists.

Sync with HEAD.

Sync with HEAD.

Update haad-dm branch to haad-dm-base2.

Move some sysctl node creations away from linksets and into the
constructors for subsystems.

XXX: CTLFLAG_PERMANENT is non-sensible.

Backout revision 1.212 and add a comment that short-cutting the WAPBL
case is not possible. The buffer length has changed and the rounded size
may not have, essentially changing the transaction size. Reported by
various users and in PR 39898.

Move WAPL replay handling from bread() into ufs_strategy.
This changes the order of hook processing as the copy-on-write handlers
are called after the journal processing. This makes more sense as the
journal overwrite is logically part of the disk IO.

If the size of the buffer didn't change, don't bother updating the WAPBL
accounting as it won't change either.

Don't dereference bp->b_vp->v_mount if its vnode type is VT_VNON. I dont
know if this masks a bug but with a machine having a ffs+wapbl mount, NFS
mounts and a ntfs mount this paniced the machine on suspend.

Sync with HEAD.

Sync with HEAD.

Merge in changes between wrstuden-revivesa-base-2 and
wrstuden-revivesa-base-3.

Sync with wrstuden-revivesa-base-2.

nestiobuf_setup(): Initialize b_dev from master buffer.

Accidental commit, but asserts buffer cache lock held

Merge the simonb-wapbl branch.  From the original branch commit:

   Add Wasabi System's WAPBL (Write Ahead Physical Block Logging)
   journaling code.  Originally written by Darrin B. Jewell while
   at Wasabi and updated to -current by Antti Kantee, Andy Doran,
   Greg Oster and Simon Burge.

OK'd by core@, releng@.

Sync with head.

bdwrite(): The COWDONE check may fire for special vnodes with mounted
           non-ffs file system.  Remove VBLK vnodes from the check.

Should fix PR kern/38892

kern/39052: fix broken assertion. We can have a BC_BUSY buffer in the LRU
queue, if it's being flushed. But in this case, we'll also have B_VFLUSH.

While there fix checkfreelist() so that it can be used to check that a
buffer is not in the free lists.

Revert white-space changes against HEAD.

Sync with HEAD.

Sync w/ -current. 34 merge conflicts to follow.

Sync with head.

Drop !cv_has_waiters assertion.

bdirty() is called from within biodone() processing before
waiters have been woken up and removed.

N.B. it is also used by smbfs.

Mark a buffer `busy` in getnewbuf() when it came from the pool_cache since
its not on a free list.

Also change buf_init() to not automatically mark buffers `busy' since this
only makes sense for bufcache buffers.

Mark all buf_init'd buffers 'busy' on the places where they ought to be
flagged as such to not confuse the buffer cache.

Fixes PR 38923.

sync with head.

Sprinkle more assertions.

Initial commit of Wasabi System's WAPBL (Write Ahead Physical Block
Logging) journaling code.  Originally written by Darrin B. Jewell
while at Wasabi and updated to -current by Antti Kantee, Andy Doran,
Greg Oster and Simon Burge.

Still a number of issues - look in doc/BRANCHES for "simonb-wapbl"
for more info.

- Make getiobuf() return buffers marked BUSY.
- Sprinkle more assertions.

sync with head

Sync with HEAD.

biodone2: if the buffer is async or has a callback method, assert that
there are no waiters on b_done (threads in biowait()).

tsleep -> kpause

brelse: always wakeup on b_busy, in case BC_WANTED is not set.

sync with head.

Make sure all cached buffers with valid, not yet written data have been
run through copy-on-write.  Call fscow_run() with valid data where possible.

The LP_UFSCOW hack is no longer needed to protect ffs_copyonwrite() against
endless recursion.

- Add a flag B_MODIFY to bread(), breada() and breadn().  If set the caller
  intends to modify the buffer returned.

- Always run copy-on-write on buffers returned from ffs_balloc().

- Add new function ffs_getblk() that gets a buffer, assigns a new blkno,
  may clear the buffer and runs copy-on-write.  Process possible errors
  from getblk() or fscow_run().  Part of PR kern/38664.

Welcome to 4.99.63

Reviewed by: YAMAMOTO Takashi <yamt@netbsd.org>

sync with head.

- Convert hashinit() to use kmem_alloc(). The hash tables can be large
  and it's better to not have them in kmem_map.
- Convert a couple of minor items along the way to kmem_alloc().
- Fix some memory leaks.

Remove clause 3 and 4 from TNF licenses

When using nested buffers, allow one erroring-out nested buffer to
error-out the master buffer.

The old setup was undeterministic since a later sheduled nested buffer
could clear the error again since there is no B_ERROR flag anymore. It also
would discard the error the nested buffer returned.

Sync with HEAD.

Make rusage collection per-LWP and collate in the appropriate places.
cloned threads need a little bit more work but the locking needs to
be fixed first.

- for some ports, especially for ones without pmap_growkernel,
  buf_memcalc is used by bootstrap as well.  fix NULL dereference for them.
- limit kva usage for each cache to 20% of vm_map.  XXX a bit arbitrary.
- add a comment.

sync with head.

sync with head.

when calculating some cache sizes, consider the amount of available kva.
PR/33185.

make buf_map static.

sync with HEAD

sync with head.

update a comment.

sync with head.

Merge all the *different* definitions of bufqueues into one common one.

Sync with HEAD.

Give bbusy() an interlock argument. If the we need to wait for the buffer,
the interlock is dropped and reacquired when awoken. This allows for
busying buffers attached to a list that is not locked by bufcache_lock.

The buffer LOCKED flag need not be under the protection of bufcache_lock,
BUSY is enough.

sync with head.

BO_COWDONE -> B_COWDONE: this flag is tested/modified from the thread owning
the buffer and therefore needs no protection by a mutex.

Ok: Andrew Doran <ad@netbsd.org>

sync with head

sync with HEAD

Sync with HEAD

Patch up sysctl locking:

- Lock processes, credentials, filehead etc correctly.
- Acquire a read hold on sysctl_treelock if only doing a query.
- Don't wire down the output buffer. It doesn't work correctly and the code
  regularly does long term sleeps with it held - it's not worth it.
- Don't hold locks other than sysctl_lock while doing copyout().
- Drop sysctl_lock while doing copyout / allocating memory in a few places.
- Don't take kernel_lock for sysctl.
- Fix a number of bugs spotted along the way

bwrite, bdwrite: bufcache_lock must be held for reassignbuf.

Catch up to netbsd-4.0 release.

Sync with HEAD

Merge vmlocking2 to head.

Sync with HEAD.

b_un.b_addr -> b_data

Sync with HEAD.

sync with head

Pull the vmlocking changes into a new branch.

Sync with HEAD.

Fscow_run(): add a flag "bool data_valid" to note still valid data.
Buffers run through copy-on-write are marked B_COWDONE.  This condition
is valid until the buffer has run through bwrite() and gets cleared from
biodone().

Welcome to 4.99.39.

Reviewed by: YAMAMOTO Takashi <yamt@netbsd.org>

buf_init(): Initialize b_iodone to NULL now that B_CALL is gone.

make allocbuf for pagedaemon fail when no buffers are available.

sync with HEAD

sysctl_bufvm_update: mutex_enter -> mutex_exit.

For biodone, only acquire kernel_lock if calling out to b_iodone. Should
push the acquire back to device drivers later.

sync with head.

Sync with HEAD.

Follow the merge of pmap.c on i386 and amd64 and move
pmap_init_tmp_pgtbl into arch/x86/x86/pmap.c. Modify the ACPI wakeup
code to restore CR4 before jumping back into kernel space as the large
page option might cover that.

Sync with HEAD.

Fix vnd(4).

Pull up following revision(s) (requested by martin in ticket #946):
	sys/kern/vfs_bio.c: revision 1.180
Fix vm.bufmem* sysctl nodes for 64bit archs by making them uint64_t,
as discussed on tech-kern. No requests for binary compat - so don't
bother to version them.

Fix vm.bufmem* sysctl nodes for 64bit archs by making them uint64_t,
as discussed on tech-kern. No requests for binary compat - so don't
bother to version them.

sync with head.

Sync with head.

Merge brelse() changes from the vmlocking branch.

Sync with HEAD.

Put the RCSID before any other headers

Sync with HEAD.

sync with head.

Sync with HEAD.

Make bioops a pointer and point it to the softdeps struct in softdep
init.  Decouples "options SOFTDEP" from the main kernel and ffs code.

- Use pool_cache for buffers.
- Simplify biodone2() slightly.

Make softdep work.

fix DEBUG.

getblk: fix a regression: don't try to preserve the buffer's contents if
allocating an fresh buffer.

Redo the buffer cache locking, mostly as proposed on tech-kern with the
exception that buffers need not be associated with vnodes. Previously
b_interlock needed to be held for nearly every operation on a buffer, in
addition to other locks like bqueue_slock, and the scheme basically did
not work. There are now three locks:

bufcache_lock: protects global buffer cache state, including softdep.

B_BUSY: long term per-buffer lock that Unix has had for ~ever.

b_objlock: lock on completion (biowait vs biodone). For buffers associated
with vnodes this points to &vp->v_interlock, since in most places that
b_objlock is taken vnode state is also being modified. If no vnode it points
to a generic lock (buffer_lock).

Sync with HEAD.

bdwrite: use bdev_type().

softdep locking improvements. It hangs looping in flush_inodedep_deps(),
more work required.

- Back out the biodone() changes.
- Eliminate B_ERROR (from HEAD).

Sync with HEAD.

Sync with HEAD.

POOL_INIT -> pool_init, we need to call bufinit() anyway

B_ERROR is gone.

file vfs_bio.c was added on branch matt-mips64 on 2007-07-29 13:53:47 +0000

B_ERROR is gone.

It's not a good idea for device drivers to modify b_flags, as they don't
need to understand the locking around that field. Instead of setting
B_ERROR, set b_error instead. b_error is 'owned' by whoever completes
the I/O request.

Get pmax working.

Allow softdep to work again. XXX This looks wrong and will be revisited.

Sync with head.

Merge some of the less invasive changes from the vmlocking branch:

- kthread, callout, devsw API changes
- select()/poll() improvements
- miscellaneous MT safety improvements

- Lock v_cleanblkhd, v_dirtyblkhd, v_numoutput with the vnode's interlock.
  Get rid of global_v_numoutput_lock. Partially incomplete as the buffer
  cache locking doesn't work very well and needs an overhaul.
- Some changes to try and make softdep MP safe. Untested.

- Increase the number of thread priorities from 128 to 256. How the space
  is set up is to be revisited.
- Implement soft interrupts as kernel threads. A generic implementation
  is provided, with hooks for fast-path MD code that can run the interrupt
  threads over the top of other threads executing in the kernel.
- Split vnode::v_flag into three fields, depending on how the flag is
  locked (by the interlock, by the vnode lock, by the file system).
- Miscellaneous locking fixes and improvements.

Sync with head.

merge yamt-idlelwp branch.  asked by core@.  some ports still needs work.

from doc/BRANCHES:

	idle lwp, and some changes depending on it.

	1. separate context switching and thread scheduling.
	   (cf. gmcgarry_ctxsw)
	2. implement idle lwp.
	3. clean up related MD/MI interfaces.
	4. make scheduler(s) modular.

- Pass the error number and residual count to biodone(), and let it handle
  setting error indicators. Prepare to eliminate B_ERROR.
- Add a flag argument to brelse() to be set into the buf's flags, instead
  of doing it directly. Typically used to set B_INVAL.
- Add a "struct cpu_info *" argument to kthread_create(), to be used to
  create bound threads. Change "bool mpsafe" to "int flags".
- Allow exit of LWPs in the IDL state when (l != curlwp).
- More locking fixes & conversion to the new API.

- Make the devsw interface MP safe, and add some comments.
- Allow individual block/character drivers to be marked MP safe.
- Provide wrappers around the device methods that look up the
  device, returning ENXIO if it's not found, and acquire the
  kernel lock if needed.

- Add two new arguments to kthread_create1: pri_t pri, bool mpsafe.
- Fork kthreads off proc0 as new LWPs, not new processes.

sync with head.

curlwp is never NULL now.

- Don't call copyout with bqueue_lock held.
- Eliminate last uses of splbio/splx.
- Fix some comments.
- Wrap some long lines.

brelse: clear the buffer structure after BUF_DESTROY.

Remove direct references to buf->b_un.b_addr instead of using buf->b_data.
This allows UVM- or other structures to be used eventually.

Pull in the initial set of changes for the vmlocking branch.

Sync with head.

Pass an ipl argument to pool_init/POOL_INIT to be used when initializing
the pool's lock.

Sync with HEAD.

Kill caddr_t; there will be some MI fallout, but it will be fixed shortly.

- sync with head.
- move sched_changepri back to kern_synch.c as it doesn't know PPQ anymore.

sync with head.

TRUE -> true, FALSE -> false

Merge newlock2 to head.

Remove support for SA. Ok core@.

sync with head.

Checkpoint work in progress.

sync with head.

Sync with head.

Export nestiobuf_iodone(). This allows nested iobufs to have a custom
call-back function that can then call the nestiobuf_iodone() to propagate.

remove some __unused from function parameters.

sync with head

with the introduction of 512 byte buffers, the index in the array is not
the number of kilobytes anymore, so name the pools appropriately.

- sprinkle __unused on function decls.
- fix a couple of unused bugs
- no more -Wno-unused for i386

sync with head.

unexport getnewbuf.

sync with head

use c99 initializers

sync with head.

sync with head.

Sync with head.

Sync with head.

move wait points for kva from upper layers to vm_map.  PR/33185 #1.

XXX there is a concern about interaction with kva fragmentation.
see: http://mail-index.NetBSD.org/tech-kern/2006/05/11/0000.html

Merge 2006-05-24 NetBSD-current into the "peter-altq" branch.

sync with head.

integrate kauth.

- Move kauth_cred_t declaration to <sys/types.h>
- Cleanup struct ucred; forward declarations that are unused.
- Don't include <sys/kauth.h> in any header, but include it in the c files
  that need it.

Approved by core.

Sync with head.

sync with head.

sync with head

Tell config to generate fs_ffs.h as vfs_bio.c checks for defined(FFS).
Include that header in vfs_bio.c so that bioops are not redefined.

sync with head.

Merge 2006-03-28 NetBSD-current into the "peter-altq" branch.

Add one more buffer pool, for 512-byte buffers.  On the one hand, most
systems will never, ever need this -- because they use 8k/1k or even,
these days, 16k/2k or 32k/4k filesystems.  On the other hand, when you
do need this, you *really* need it: on anoncvs.netbsd.org, for instance,
where /tmp is 4k/512 and the filesystem contains tens or even hundreds
of thousands of single-frag directories, this essentially doubles the
efficiency of the allocator.  Since the overhead of keeping one extra
pool around is minimal, just add it by default.

sync with head.

Adapt to kernel authorization KPI.

Move ISSET/SET/CLR macros to sys/types.h

sync with head.

nestiobuf_iodone: remove a comment which is no longer true.

sync with head.

Propagate an appropiate error code in nestiobuf_iodone() to the master
buffer when the passed nested buffer has no B_ERROR flag set but not all
was transfered for the nested iobuf extent.

Discussed on tech-kern and ok'd by Takashi

sync with head.

allocbuf: yield cpu in a loop.

- use POOL_INIT for bufpool.
- make bufiopool static.

add nestiobuf api for convenience when splitting a request to several pieces.

remove B_EINTR as it isn't used anymore.

use a dedicated buf pool for getiobuf.

- add simple functions to allocate/free a buffer for i/o.
- make bufpool static.

Remove leading __ from __(const|inline|signed|volatile) -- it is obsolete.

merge ktrace-lwp.

Sync with HEAD. Here we go again...

Properly fix the constipated lossage wrt -Wcast-qual and the sysctl
code.  I know it's not the prettiest code, but it seems to work rather
well in spite of itself.

- add const.
- remove unnecessary casts.
- add __UNCONST casts and mark them with XXXUNCONST as necessary.

Pull up revision 1.143 (requested by chs in ticket #1380):
fix validation of new values when setting vm.{hi,low}water.  fixes PR 29651.

sync with -current

Pull up revision 1.143 (requested by chs in ticket #82):
fix validation of new values when setting vm.{hi,low}water.  fixes PR 29651.

Sync with HEAD.

merge yamt-km branch.
- don't use managed mappings/backing objects for wired memory allocations.
  save some resources like pv_entry.  also fix (most of) PR/27030.
- simplify kernel memory management API.
- simplify pmap bootstrap of some ports.
- some related cleanups.

fix validation of new values when setting vm.{hi,low}water.  fixes PR 29651.

sync with head.  xen and whitespace.  xen part is not finished.

Sync with HEAD.

Hi Perry!

nuke trailing whitespace

convert to new apis.

Sync with HEAD.

Users have observed that the amount of memory used by the metadata cache
can in some situations exceed the high-water mark, and stay there once it
gets there.  Adjust the canrelease function so that it will immediately
bring us back down to the high-water mark in this situation.

How can this happen at all?  Consider a machine with two filesystems, one
with a much larger blocksize than the other.  If the small-block filesystem
is very busy, growing the cache up to the high-water mark, and then the
large-block filesystem becomes busy, buffers will be recycled (since we
are at the high-water mark) but _grow each time they're recycled_.  Once
we're above the high-water mark, the canrelease call in allocbuf (without
this change) doesn't shrink us back down below it; so things get worse and
worse.

also define bioops if FFS is not defined.

Sync with HEAD.

Fix previous commit, got bufcache and bufmem messages reversed.