Add vnode_pager_clean_{a,}sync(9)

Bump __FreeBSD_version for ZFS use.

Reviewed by: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D43356

sys: Automated cleanup of cdefs and other formatting

Apply the following automated changes to try to eliminate
no-longer-needed sys/cdefs.h includes as well as now-empty
blank lines in a row.

Remove /^#if.*\n#endif.*\n#include\s+<sys/cdefs.h>.*\n/
Remove /\n+#include\s+<sys/cdefs.h>.*\n+#if.*\n#endif.*\n+/
Remove /\n+#if.*\n#endif.*\n+/
Remove /^#if.*\n#endif.*\n/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/types.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/param.h>/
Remove /\n+#include\s+<sys/cdefs.h>\n#include\s+<sys/capsicum.h>/

Sponsored by: Netflix

sys: Remove ancient SCCS tags.

Remove ancient SCCS tags from the tree, automated scripting, with two
minor fixup to keep things compiling. All the common forms in the tree
were removed with a perl script.

Sponsored by: Netflix

sys: Remove $FreeBSD$: one-line .c pattern

Remove /^[\s*]*__FBSDID\("\$FreeBSD\$"\);?\s*\n/

FIOSEEKHOLE/FIOSEEKDATA: correct consistency for bmap-based implementation

Writes on UFS through a mapped region do not allocate disk blocks in
holes immediately. The blocks are allocated when the pages are paged out
first time.

This breaks the algorithm in vn_bmap_seekhole() and ufs_bmap_seekdata(),
because VOP_BMAP() reports hole for the place which already contains a
valid data.

Clean the pages before doing VOP_BMAP() in the affected functions. In
principle, we could clean less by only requesting clean starting from
the offset, but it is probably not very important.

PR: 269261
Reported by: asomers
Reviewed by: asomers, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D38379

Rewrite function definitions in the UFS/FFS code base with identifier lists.

The K&R style in UFS and other places in the tree's days are numbered
as this syntax is removed in C2x proposal N2432:

https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2432.pdf

Though running to nearly 6000 lines of diffs this update should cause
no functional change to the code.

Requested by: Warner Losh
MFC after: 2 weeks

ufs: Use IS_SNAPSHOT()

Reviewed by: markj, mckusick
Tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D34072

ufs: clean up empty lines in .c and .h files

The error reported in FS-14-UFS-3 can only happen on UFS/FFS
filesystems that have block pointers that are out-of-range for their
filesystem. These out-of-range block pointers are corrected by
fsck(8) so are only encountered when an unchecked filesystem is
mounted.

A new "untrusted" flag has been added to the generic mount interface
that can be set when mounting media of unknown provenance or integrity.
For example, a daemon that automounts a filesystem on a flash drive
when it is plugged into a system.

This commit adds a test to UFS/FFS that validates all block numbers
before using them. Because checking for out-of-range blocks adds
unnecessary overhead to normal operation, the tests are only done
when the filesystem is mounted as an "untrusted" filesystem.

Reported by: Christopher Krah, Thomas Barabosch, and Jan-Niclas Hilgert of Fraunhofer FKIE
Reported as: FS-14-UFS-3: Out of bounds read in write-2 (ffs_alloccg)
Reviewed by: kib
Sponsored by: Netflix

Add FIOBMAP2 ioctl

This ioctl exposes VOP_BMAP information to userland. It can be used by
programs like fragmentation analyzers and optimized cp implementations. But
I'm using it to test fusefs's VOP_BMAP implementation. The "2" in the name
distinguishes it from the similar but incompatible FIBMAP ioctls in NetBSD
and Linux. FIOBMAP2 differs from FIBMAP in that it uses a 64-bit block
number instead of 32-bit, and it also returns runp and runb.

Reviewed by: mckusick
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20705

Ensure that error is initialized in ufs_bmap_seekdata().

Reported and tested by: jhibbits
MFC with: r346932
Sponsored by: The FreeBSD Foundation

Optimize lseek(SEEK_DATA) on UFS.

This version fixes the problems identified in r345244.

Reviewed by: kib
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19598

Revert r345244 for now.

The code which advances the block number is simplistic and is not
correct when the starting offset is non-zero. Revert the change until
this is fixed.

Fix the gcc build (-Wstrict-prototypes) after r345244.

Reported by: jenkins
MFC with: r345244

Optimize lseek(SEEK_DATA) on UFS.

The old implementation, at the VFS layer, would map the entire range of
logical blocks between the starting offset and the first data block
following that offset. With large sparse files this is very
inefficient. The VFS currently doesn't provide an interface to improve
upon the current implementation in a generic way.

Add ufs_bmap_seekdata(), which uses the obvious algorithm of scanning
indirect blocks to look for data blocks. Use it instead of
vn_bmap_seekhole() to implement SEEK_DATA.

Reviewed by: kib, mckusick
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19598

sys: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.

Renumber copyright clause 4

Renumber cluase 4 to 3, per what everybody else did when BSD granted
them permission to remove clause 3. My insistance on keeping the same
numbering for legal reasons is too pedantic, so give up on that point.

Submitted by: Jan Schaumann <jschauma@stevens.edu>
Pull Request: https://github.com/freebsd/freebsd/pull/96

prefix UFS symbols with UFS_ to reduce namespace pollution

Specifically:
ROOTINO -> UFS_ROOTINO
WINO -> UFS_WINO
NXADDR -> UFS_NXADDR
NDADDR -> UFS_NDADDR
NIADDR -> UFS_NIADDR
MAXSYMLINKLEN_UFS[12] -> UFS[12]_MAXSYMLINKLEN (for consistency)

Also prefix ext2's and nandfs's NDADDR and NIADDR with EXT2_ and NANDFS_

Reviewed by: kib, mckusick
Obtained from: NetBSD
MFC after: 1 month
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D9536

Reduce size of ufs inode.

Remove redunand i_dev and i_fs pointers, which are available as
ip->i_ump->um_dev and ip->i_ump->um_fs, and reorder members by size to
reduce padding. To compensate added derefences, the most often i_ump
access to differentiate between UFS1 and UFS2 dinode layout is
removed, by addition of the new i_flag IN_UFS2. Overall, this
actually reduces the amount of memory dereferences.

On 64bit machine, original struct inode size is 176, reduced to 152
bytes with the change.

Tested by: pho (previous version)
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks

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

Remove several write-only variables, all reported by the gcc 4.9
buildkernel run.

Some of them were write-only under some kernel options, e.g. variables
keeping values only used by CTR() macros. It costs nothing to the
code readability and correctness to eliminate the warnings in those
cases too by removing the local cached values used only for
single-access.

Review: https://reviews.freebsd.org/D2665
Reviewed by: rodrigc
Looked at by: bjk
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Remove unused member of struct indir (in_exists) from UFS and EXT2 code.

Reviewed by: mckusick
Approved by: trasz (mentor)
MFC after: 1 week

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

- Import the HEAD csup code which is the basis for the cvsmode work.

Turn most ffs 'DIAGNOSTIC's into INVARIANTS.

- Move rusage from being per-process in struct pstats to per-thread in
td_ru. This removes the requirement for per-process synchronization in
statclock() and mi_switch(). This was previously supported by
sched_lock which is going away. All modifications to rusage are now
done in the context of the owning thread. reads proceed without locks.
- Aggregate exiting threads rusage in thread_exit() such that the exiting
thread's rusage is not lost.
- Provide a new routine, rufetch() to fetch an aggregate of all rusage
structures from all threads in a process. This routine must be used
in any place requiring a rusage from a process prior to it's exit. The
exited process's rusage is still available via p_ru.
- Aggregate tick statistics only on demand via rufetch() or when a thread
exits. Tick statistics are kept in the thread and protected by sched_lock
until it exits.

Initial patch by: attilio
Reviewed by: attilio, bde (some objections), arch (mostly silent)

Remove an unneeded "a" from comment.

/* -> /*- for license, minor formatting changes

Make VOP_BMAP return a struct bufobj for the underlying storage device
instead of a vnode for it.

The vnode_pager does not and should not have any interest in what
the filesystem uses for backend.

(vfs_cluster doesn't use the backing store argument.)

Move the buffer method vector (buf->b_op) to the bufobj.

Extend it with a strategy method.

Add bufstrategy() which do the usual VOP_SPECSTRATEGY/VOP_STRATEGY
song and dance.

Rename ibwrite to bufwrite().

Move the two NFS buf_ops to more sensible places, add bufstrategy
to them.

Add inlines for bwrite() and bstrategy() which calls through
buf->b_bufobj->b_ops->b_{write,strategy}().

Replace almost all VOP_STRATEGY()/VOP_SPECSTRATEGY() calls with bstrategy().

Add b_bufobj to struct buf which eventually will eliminate the need for b_vp.

Initialize b_bufobj for all buffers.

Make incore() and gbincore() take a bufobj instead of a vnode.

Make inmem() local to vfs_bio.c

Change a lot of VI_[UN]LOCK(bp->b_vp) to BO_[UN]LOCK(bp->b_bufobj)
also VI_MTX() to BO_MTX(),

Make buf_vlist_add() take a bufobj instead of a vnode.

Eliminate other uses of bp->b_vp where bp->b_bufobj will do.

Various minor polishing: remove "register", turn panic into KASSERT,
use new function declarations, TAILQ_FOREACH_SAFE() etc.

Remove advertising clause from University of California Regent's
license, per letter dated July 22, 1999 and irc message from Robert
Watson saying that clause 3 can be removed from those files with an
NAI copyright that also have only a University of California
copyrights.

Approved by: core, rwatson

DuH!

bp->b_iooffset (the spot on the disk), not bp->b_offset (the offset in
the file)

Initialize bp->b_offset before calling VOP_[SPEC]STRATEGY()

Use __FBSDID().

- Add a new 'flags' parameter to getblk().
- Define one flag GB_LOCK_NOWAIT that tells getblk() to pass the LK_NOWAIT
flag to the initial BUF_LOCK(). This will eventually be used in cases
were we want to use a buffer only if it is not currently in use.
- Convert all consumers of the getblk() api to use this extra parameter.

Reviwed by: arch
Not objected to by: mckusick

Convert calls to BUF_STRATEGY to VOP_STRATEGY calls. This is a no-op since
all BUF_STRATEGY did in the first place was call VOP_STRATEGY.

Add support to UFS2 to provide storage for extended attributes.
As this code is not actually used by any of the existing
interfaces, it seems unlikely to break anything (famous
last words).

The internal kernel interface to manipulate these attributes
is invoked using two new IO_ flags: IO_NORMAL and IO_EXT.
These flags may be specified in the ioflags word of VOP_READ,
VOP_WRITE, and VOP_TRUNCATE. Specifying IO_NORMAL means that
you want to do I/O to the normal data part of the file and
IO_EXT means that you want to do I/O to the extended attributes
part of the file. IO_NORMAL and IO_EXT are mutually exclusive
for VOP_READ and VOP_WRITE, but may be specified individually
or together in the case of VOP_TRUNCATE. For example, when
removing a file, VOP_TRUNCATE is called with both IO_NORMAL
and IO_EXT set. For backward compatibility, if neither IO_NORMAL
nor IO_EXT is set, then IO_NORMAL is assumed.

Note that the BA_ and IO_ flags have been `merged' so that they
may both be used in the same flags word. This merger is possible
by assigning the IO_ flags to the low sixteen bits and the BA_
flags the high sixteen bits. This works because the high sixteen
bits of the IO_ word is reserved for read-ahead and help with
write clustering so will never be used for flags. This merge
lets us get away from code of the form:

if (ioflags & IO_SYNC)
flags |= BA_SYNC;

For the future, I have considered adding a new field to the
vattr structure, va_extsize. This addition could then be
exported through the stat structure to allow applications to
find out the size of the extended attribute storage and also
would provide a more standard interface for truncating them
(via VOP_SETATTR rather than VOP_TRUNCATE).

I am also contemplating adding a pathconf parameter (for
concreteness, lets call it _PC_MAX_EXTSIZE) which would
let an application determine the maximum size of the extended
atribute storage.

Sponsored by: DARPA & NAI Labs.

This commit adds basic support for the UFS2 filesystem. The UFS2
filesystem expands the inode to 256 bytes to make space for 64-bit
block pointers. It also adds a file-creation time field, an ability
to use jumbo blocks per inode to allow extent like pointer density,
and space for extended attributes (up to twice the filesystem block
size worth of attributes, e.g., on a 16K filesystem, there is space
for 32K of attributes). UFS2 fully supports and runs existing UFS1
filesystems. New filesystems built using newfs can be built in either
UFS1 or UFS2 format using the -O option. In this commit UFS1 is
the default format, so if you want to build UFS2 format filesystems,
you must specify -O 2. This default will be changed to UFS2 when
UFS2 proves itself to be stable. In this commit the boot code for
reading UFS2 filesystems is not compiled (see /sys/boot/common/ufsread.c)
as there is insufficient space in the boot block. Once the size of the
boot block is increased, this code can be defined.

Things to note: the definition of SBSIZE has changed to SBLOCKSIZE.
The header file <ufs/ufs/dinode.h> must be included before
<ufs/ffs/fs.h> so as to get the definitions of ufs2_daddr_t and
ufs_lbn_t.

Still TODO:
Verify that the first level bootstraps work for all the architectures.
Convert the utility ffsinfo to understand UFS2 and test growfs.
Add support for the extended attribute storage. Update soft updates
to ensure integrity of extended attribute storage. Switch the
current extended attribute interfaces to use the extended attribute
storage. Add the extent like functionality (framework is there,
but is currently never used).

Sponsored by: DARPA & NAI Labs.
Reviewed by: Poul-Henning Kamp <phk@freebsd.org>

Fix two casts to "daddr_t *" that should have been "ufs_daddr_t *".

Fix ufs_daddr_t/daddr_t type problems.

Sponsored by: DARPA & NAI labs.

Make daddr_t and u_daddr_t 64bits wide.
Retire daddr64_t and use daddr_t instead.

Sponsored by: DARPA & NAI Labs.

Remove register keyword.

Sponsored by: DARPA & NAI Labs.
Submitted by: mckusick

Introduce the new 64-bit size disk block, daddr64_t. Change
the bio and buffer structures to have daddr64_t bio_pblkno,
b_blkno, and b_lblkno fields which allows access to disks
larger than a Terabyte in size. This change also requires
that the VOP_BMAP vnode operation accept and return daddr64_t
blocks. This delta should not affect system operation in
any way. It merely sets up the necessary interfaces to allow
the development of disk drivers that work with these larger
disk block addresses. It also allows for the development of
UFS2 which will use 64-bit block addresses.

Remove two unused arguments from ufs_bmaparray().

Revert consequences of changes to mount.h, part 2.

Requested by: bde

Correct #includes to work with fixed sys/mount.h.

This patch corrects the first round of panics and hangs reported
with the new snapshot code.

Update addaliasu to correctly implement the semantics of the old
checkalias function. When a device vnode first comes into existence,
check to see if an anonymous vnode for the same device was created
at boot time by bdevvp(). If so, adopt the bdevvp vnode rather than
creating a new vnode for the device. This corrects a problem which
caused the kernel to panic when taking a snapshot of the root
filesystem.

Change the calling convention of vn_write_suspend_wait() to be the
same as vn_start_write().

Split out softdep_flushworklist() from softdep_flushfiles() so that
it can be used to clear the work queue when suspending filesystem
operations.

Access to buffers becomes recursive so that snapshots can recursively
traverse their indirect blocks using ffs_copyonwrite() when checking
for the need for copy on write when flushing one of their own indirect
blocks. This eliminates a deadlock between the syncer daemon and a
process taking a snapshot.

Ensure that softdep_process_worklist() can never block because of a
snapshot being taken. This eliminates a problem with buffer starvation.

Cleanup change in ffs_sync() which did not synchronously wait when
MNT_WAIT was specified. The result was an unclean filesystem panic
when doing forcible unmount with heavy filesystem I/O in progress.

Return a zero'ed block when reading a block that was not in use at
the time that a snapshot was taken. Normally, these blocks should
never be read. However, the readahead code will occationally read
them which can cause unexpected behavior.

Clean up the debugging code that ensures that no blocks be written
on a filesystem while it is suspended. Snapshots must explicitly
label the blocks that they are writing during the suspension so that
they do not cause a `write on suspended filesystem' panic.

Reorganize ffs_copyonwrite() to eliminate a deadlock and also to
prevent a race condition that would permit the same block to be
copied twice. This change eliminates an unexpected soft updates
inconsistency in fsck caused by the double allocation.

Use bqrelse rather than brelse for buffers that will be needed
soon again by the snapshot code. This improves snapshot performance.

Add snapshots to the fast filesystem. Most of the changes support
the gating of system calls that cause modifications to the underlying
filesystem. The gating can be enabled by any filesystem that needs
to consistently suspend operations by adding the vop_stdgetwritemount
to their set of vnops. Once gating is enabled, the function
vfs_write_suspend stops all new write operations to a filesystem,
allows any filesystem modifying system calls already in progress
to complete, then sync's the filesystem to disk and returns. The
function vfs_write_resume allows the suspended write operations to
begin again. Gating is not added by default for all filesystems as
for SMP systems it adds two extra locks to such critical kernel
paths as the write system call. Thus, gating should only be added
as needed.

Details on the use and current status of snapshots in FFS can be
found in /sys/ufs/ffs/README.snapshot so for brevity and timelyness
is not included here. Unless and until you create a snapshot file,
these changes should have no effect on your system (famous last words).

Separate the struct bio related stuff out of <sys/buf.h> into
<sys/bio.h>.

<sys/bio.h> is now a prerequisite for <sys/buf.h> but it shall
not be made a nested include according to bdes teachings on the
subject of nested includes.

Diskdrivers and similar stuff below specfs::strategy() should no
longer need to include <sys/buf.> unless they need caching of data.

Still a few bogus uses of struct buf to track down.

Repocopy by: peter

s/biowait/bufwait/g

Prodded by: several.

Remove ~25 unneeded #include <sys/conf.h>
Remove ~60 unneeded #include <sys/malloc.h>

Introduce extended attribute support for FFS, allowing arbitrary
(name, value) pairs to be associated with inodes. This support is
used for ACLs, MAC labels, and Capabilities in the TrustedBSD
security extensions, which are currently under development.

In this implementation, attributes are backed to data vnodes in the
style of the quota support in FFS. Support for FFS extended
attributes may be enabled using the FFS_EXTATTR kernel option
(disabled by default). Userland utilities and man pages will be
committed in the next batch. VFS interfaces and man pages have
been in the repo since 4.0-RELEASE and are unchanged.

o ufs/ufs/extattr.h: UFS-specific extattr defines
o ufs/ufs/ufs_extattr.c: bulk of support routines
o ufs/{ufs,ffs,mfs}/*.[ch]: hooks and extattr.h includes
o contrib/softupdates/ffs_softdep.c: extattr.h includes
o conf/options, conf/files, i386/conf/LINT: added FFS_EXTATTR

o coda/coda_vfsops.c: XXX required extattr.h due to ufsmount.h
(This should not be the case, and will be fixed in a future commit)

Currently attributes are not supported in MFS. This will be fixed.

Reviewed by: adrian, bp, freebsd-fs, other unthanked souls
Obtained from: TrustedBSD Project

Move B_ERROR flag to b_ioflags and call it BIO_ERROR.

(Much of this done by script)

Move B_ORDERED flag to b_ioflags and call it BIO_ORDERED.

Move b_pblkno and b_iodone_chain to struct bio while we transition, they
will be obsoleted once bio structs chain/stack.

Add bio_queue field for struct bio aware disksort.

Address a lot of stylistic issues brought up by bde.

Rename the existing BUF_STRATEGY() to DEV_STRATEGY()

substitute BUF_WRITE(foo) for VOP_BWRITE(foo->b_vp, foo)

substitute BUF_STRATEGY(foo) for VOP_STRATEGY(foo->b_vp, foo)

This patch is machine generated except for the ccd.c and buf.h parts.

Remove B_READ, B_WRITE and B_FREEBUF and replace them with a new
field in struct buf: b_iocmd. The b_iocmd is enforced to have
exactly one bit set.

B_WRITE was bogusly defined as zero giving rise to obvious coding
mistakes.

Also eliminate the redundant struct buf flag B_CALL, it can just
as efficiently be done by comparing b_iodone to NULL.

Should you get a panic or drop into the debugger, complaining about
"b_iocmd", don't continue. It is likely to write on your disk
where it should have been reading.

This change is a step in the direction towards a stackable BIO capability.

A lot of this patch were machine generated (Thanks to style(9) compliance!)

Vinum users: Greg has not had time to test this yet, be careful.

Bug fixes for currently harmless bugs that could rise to bite
the unwary if the code were called in slightly different ways.

1) In ufs_bmaparray() the code for calculating 'runb' will stop one block
short of the first entry in an indirect block. i.e. if an indirect block
contains N block numbers b[0]..b[N-1] then the code will never check if
b[0] and b[1] are sequential. For reference, compare with the equivalent
code that deals with direct blocks.

2) In ufs_lookup() there is an off-by-one error in the test that checks
if dp->i_diroff is outside the range of the the current directory size.
This is completely harmless, since the following while-loop condition
'dp->i_offset < endsearch' is never met, so the code immediately
does a second pass starting at dp->i_offset = 0.

3) Again in ufs_lookup(), the condition in a sanity check is wrong
for directories that are longer than one block. This bug means that
the sanity check is only effective for small directories.

Submitted by: Ian Dowse <iedowse@maths.tcd.ie>

Remove v_maxio from struct vnode.

Replace it with mnt_iosize_max in struct mount.

Nits from: bde

Fix a harmless bug I introduced, simplify a bit more while here.

Step one of replacing devsw->d_maxio with si_bsize_max.

Rename dev->si_bsize_max to si_iosize_max and set it in spec_open
if the device didn't.

Set vp->v_maxio from dev->si_bsize_max in spec_open rather than
in ufs_bmap.c

$Id$ -> $FreeBSD$

The bdevsw() and cdevsw() are now identical, so kill the former.

Decommision miscfs/specfs/specdev.h. Most of it goes into <sys/conf.h>,
a few lines into <sys/vnode.h>.

Add a few fields to struct specinfo, paving the way for the fun part.

I got tired of seeing all the cdevsw[major(foo)] all over the place.

Made a new (inline) function devsw(dev_t dev) and substituted it.

Changed to the BDEV variant to this format as well: bdevsw(dev_t dev)

DEVFS will eventually benefit from this change too.

Continue where Julian left off in July 1998:

Virtualize bdevsw[] from cdevsw. bdevsw() is now an (inline)
function.

Join CDEV_MODULE and BDEV_MODULE to DEV_MODULE (please pay attention
to the order of the cmaj/bmaj arguments!)

Join CDEV_DRIVER_MODULE and BDEV_DRIVER_MODULE to DEV_DRIVER_MODULE
(ditto!)

(Next step will be to convert all bdev dev_t's to cdev dev_t's
before they get to do any damage^H^H^H^H^H^Hwork in the kernel.)

The VFS/BIO subsystem contained a number of hacks in order to optimize
piecemeal, middle-of-file writes for NFS. These hacks have caused no
end of trouble, especially when combined with mmap(). I've removed
them. Instead, NFS will issue a read-before-write to fully
instantiate the struct buf containing the write. NFS does, however,
optimize piecemeal appends to files. For most common file operations,
you will not notice the difference. The sole remaining fragment in
the VFS/BIO system is b_dirtyoff/end, which NFS uses to avoid cache
coherency issues with read-merge-write style operations. NFS also
optimizes the write-covers-entire-buffer case by avoiding the
read-before-write. There is quite a bit of room for further
optimization in these areas.

The VM system marks pages fully-valid (AKA vm_page_t->valid =
VM_PAGE_BITS_ALL) in several places, most noteably in vm_fault. This
is not correct operation. The vm_pager_get_pages() code is now
responsible for marking VM pages all-valid. A number of VM helper
routines have been added to aid in zeroing-out the invalid portions of
a VM page prior to the page being marked all-valid. This operation is
necessary to properly support mmap(). The zeroing occurs most often
when dealing with file-EOF situations. Several bugs have been fixed
in the NFS subsystem, including bits handling file and directory EOF
situations and buf->b_flags consistancy issues relating to clearing
B_ERROR & B_INVAL, and handling B_DONE.

getblk() and allocbuf() have been rewritten. B_CACHE operation is now
formally defined in comments and more straightforward in
implementation. B_CACHE for VMIO buffers is based on the validity of
the backing store. B_CACHE for non-VMIO buffers is based simply on
whether the buffer is B_INVAL or not (B_CACHE set if B_INVAL clear,
and vise-versa). biodone() is now responsible for setting B_CACHE
when a successful read completes. B_CACHE is also set when a bdwrite()
is initiated and when a bwrite() is initiated. VFS VOP_BWRITE
routines (there are only two - nfs_bwrite() and bwrite()) are now
expected to set B_CACHE. This means that bowrite() and bawrite() also
set B_CACHE indirectly.

There are a number of places in the code which were previously using
buf->b_bufsize (which is DEV_BSIZE aligned) when they should have
been using buf->b_bcount. These have been fixed. getblk() now clears
B_DONE on return because the rest of the system is so bad about
dealing with B_DONE.

Major fixes to NFS/TCP have been made. A server-side bug could cause
requests to be lost by the server due to nfs_realign() overwriting
other rpc's in the same TCP mbuf chain. The server's kernel must be
recompiled to get the benefit of the fixes.

Submitted by: Matthew Dillon <dillon@apollo.backplane.com>

Fix warnings in preparation for adding -Wall -Wcast-qual to the
kernel compile

Oops, the redundant tests for major numbers weren't redundant here.
They checked for the magic major number for the "device" behind mfs
mount points. Use a more obvious check for this device.

Debugged by: Andrew Gallatin <gallatin@cs.duke.edu>

Removed redundant bitrotted checks for major numbers instead of updating
them.

Quick fix for breakage of read clustering on non-IDE drives. Read
clustering is obsolescent technology so hardly anyone noticed. On
a DORS 32160 SCSI drive with 4 tags, read clustering makes very
little difference even for huge sequential reads. However, on a
ZIP SCSI drive with 0 tags, the minimum overhead per block is about
40 msec, so very large clusters must be used to get anywhere near
the maximum transfer rate. Using clusters consisting of 1 8K block
reduces the transfer rate to about 250K/sec. Under msdosfs, missing
read clustering is normal and a cluster size of 1 512 byte block
reduces the transfer rate to about 25K/sec.

Broken in: rev.1.18

VOP_STRATEGY grows an (struct vnode *) argument
as the value in b_vp is often not really what you want.
(and needs to be frobbed). more cleanups will follow this.
Reviewed by: Bruce Evans <bde@freebsd.org>

Back out DIAGNOSTIC changes.

Turn DIAGNOSTIC into a new-style option.

Add better support for larger I/O clusters, including larger physical
I/O. The support is not mature yet, and some of the underlying implementation
needs help. However, support does exist for IDE devices now.

Fixed overflow in ufs_getblns(). For ufs on systems with 32-bit ints,
triple indirect blocks only worked for block sizes of 4K, since
MNINDIR(ump)**3 overflows for larger block sizes (e.g.,
(8192/4)**3 = 2**33 > INT_MAX). This fix is not the obvious one of
changing some types to 64 bits. It rearranges the code to avoid some
unnecessary 64-bit calculations.

Reviewed by: Kirk McKusick <mckusick@McKusick.COM>

Removed unused #includes.

Update a number of routines to reflect the actual name
of the routine that caused the panic.

Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not
ready for it yet.

This is the kernel Lite/2 commit. There are some requisite userland
changes, so don't expect to be able to run the kernel as-is (very well)
without the appropriate Lite/2 userland changes.

The system boots and can mount UFS filesystems.

Untested: ext2fs, msdosfs, NFS
Known problems: Incorrect Berkeley ID strings in some files.
Mount_std mounts will not work until the getfsent
library routine is changed.

Reviewed by: various people
Submitted by: Jeffery Hsu <hsu@freebsd.org>

Make the long-awaited change from $Id$ to $FreeBSD$

This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.

Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.

Import 4.4BSD-Lite2 onto the vendor branch, note that in the kernel, all
files are off the vendor branch, so this should not change anything.

A "U" marker generally means that the file was not changed in between
the 4.4Lite and Lite-2 releases, and does not need a merge. "C" generally
means that there was a change.

Eliminated many redundant vm_map_lookup operations for vm_mmap.
Speed up for vfs_bio -- addition of a routine bqrelse to greatly diminish
overhead for merged cache.
Efficiency improvement for vfs_cluster. It used to do alot of redundant
calls to cluster_rbuild.
Correct the ordering for vrele of .text and release of credentials.
Use the selective tlb update for 486/586/P6.
Numerous fixes to the size of objects allocated for files. Additionally,
fixes in the various pagers.
Fixes for proper positioning of vnode_pager_setsize in msdosfs and ext2fs.
Fixes in the swap pager for exhausted resources. The pageout code
will not as readily thrash.
Change the page queue flags (PG_ACTIVE, PG_INACTIVE, PG_FREE, PG_CACHE) into
page queue indices (PQ_ACTIVE, PQ_INACTIVE, PQ_FREE, PQ_CACHE),
thereby improving efficiency of several routines.
Eliminate even more unnecessary vm_page_protect operations.
Significantly speed up process forks.
Make vm_object_page_clean more efficient, thereby eliminating the pause
that happens every 30seconds.
Make sequential clustered writes B_ASYNC instead of B_DELWRI even in the
case of filesystems mounted async.
Fix a panic with busy pages when write clustering is done for non-VMIO
buffers.

Fix ufs_bmap so that triple indirect blocks might work.
Submitted by: Godmar Back <gback@facility.cs.utah.edu>

Added VOP_GETPAGES/VOP_PUTPAGES and also the "backwards" block count
for VOP_BMAP. Updated affected filesystems...

Remove trailing whitespace.

Add and move declarations to fix all of the warnings from `gcc -Wimplicit'
(except in netccitt, netiso and netns) that I didn't notice when I fixed
"all" such warnings before.

Removed obsolete vtrace() remnants.

These changes embody the support of the fully coherent merged VM buffer cache,
much higher filesystem I/O performance, and much better paging performance. It
represents the culmination of over 6 months of R&D.

The majority of the merged VM/cache work is by John Dyson.

The following highlights the most significant changes. Additionally, there are
(mostly minor) changes to the various filesystem modules (nfs, msdosfs, etc) to
support the new VM/buffer scheme.

vfs_bio.c:
Significant rewrite of most of vfs_bio to support the merged VM buffer cache
scheme. The scheme is almost fully compatible with the old filesystem
interface. Significant improvement in the number of opportunities for write
clustering.

vfs_cluster.c, vfs_subr.c
Upgrade and performance enhancements in vfs layer code to support merged
VM/buffer cache. Fixup of vfs_cluster to eliminate the bogus pagemove stuff.

vm_object.c:
Yet more improvements in the collapse code. Elimination of some windows that
can cause list corruption.

vm_pageout.c:
Fixed it, it really works better now. Somehow in 2.0, some "enhancements"
broke the code. This code has been reworked from the ground-up.

vm_fault.c, vm_page.c, pmap.c, vm_object.c
Support for small-block filesystems with merged VM/buffer cache scheme.

pmap.c vm_map.c
Dynamic kernel VM size, now we dont have to pre-allocate excessive numbers of
kernel PTs.

vm_glue.c
Much simpler and more effective swapping code. No more gratuitous swapping.

proc.h
Fixed the problem that the p_lock flag was not being cleared on a fork.

swap_pager.c, vnode_pager.c
Removal of old vfs_bio cruft to support the past pseudo-coherency. Now the
code doesn't need it anymore.

machdep.c
Changes to better support the parameter values for the merged VM/buffer cache
scheme.

machdep.c, kern_exec.c, vm_glue.c
Implemented a seperate submap for temporary exec string space and another one
to contain process upages. This eliminates all map fragmentation problems
that previously existed.

ffs_inode.c, ufs_inode.c, ufs_readwrite.c
Changes for merged VM/buffer cache. Add "bypass" support for sneaking in on
busy buffers.

Submitted by: John Dyson and David Greenman

POSSIBLE BOGUS CODE found, (related to dos-partitions) in ufs_disksubr.c,
look for CC_WALL.
Cosmetics, a couple of unused vars.

Added $Id$

The big 4.4BSD Lite to FreeBSD 2.0.0 (Development) patch.

Reviewed by: Rodney W. Grimes
Submitted by: John Dyson and David Greenman

BSD 4.4 Lite Kernel Sources