- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Change the cap_rights_t type from uint64_t to a structure that we can extend
in the future in a backward compatible (API and ABI) way.

The cap_rights_t represents capability rights. We used to use one bit to
represent one right, but we are running out of spare bits. Currently the new
structure provides place for 114 rights (so 50 more than the previous
cap_rights_t), but it is possible to grow the structure to hold at least 285
rights, although we can make it even larger if 285 rights won't be enough.

The structure definition looks like this:

struct cap_rights {
uint64_t cr_rights[CAP_RIGHTS_VERSION + 2];
};

The initial CAP_RIGHTS_VERSION is 0.

The top two bits in the first element of the cr_rights[] array contain total
number of elements in the array - 2. This means if those two bits are equal to
0, we have 2 array elements.

The top two bits in all remaining array elements should be 0.
The next five bits in all array elements contain array index. Only one bit is
used and bit position in this five-bits range defines array index. This means
there can be at most five array elements in the future.

To define new right the CAPRIGHT() macro must be used. The macro takes two
arguments - an array index and a bit to set, eg.

#define CAP_PDKILL CAPRIGHT(1, 0x0000000000000800ULL)

We still support aliases that combine few rights, but the rights have to belong
to the same array element, eg:

#define CAP_LOOKUP CAPRIGHT(0, 0x0000000000000400ULL)
#define CAP_FCHMOD CAPRIGHT(0, 0x0000000000002000ULL)

#define CAP_FCHMODAT (CAP_FCHMOD | CAP_LOOKUP)

There is new API to manage the new cap_rights_t structure:

cap_rights_t *cap_rights_init(cap_rights_t *rights, ...);
void cap_rights_set(cap_rights_t *rights, ...);
void cap_rights_clear(cap_rights_t *rights, ...);
bool cap_rights_is_set(const cap_rights_t *rights, ...);

bool cap_rights_is_valid(const cap_rights_t *rights);
void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src);
void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src);
bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little);

Capability rights to the cap_rights_init(), cap_rights_set(),
cap_rights_clear() and cap_rights_is_set() functions are provided by
separating them with commas, eg:

cap_rights_t rights;

cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT);

There is no need to terminate the list of rights, as those functions are
actually macros that take care of the termination, eg:

#define cap_rights_set(rights, ...) \
__cap_rights_set((rights), __VA_ARGS__, 0ULL)
void __cap_rights_set(cap_rights_t *rights, ...);

Thanks to using one bit as an array index we can assert in those functions that
there are no two rights belonging to different array elements provided
together. For example this is illegal and will be detected, because CAP_LOOKUP
belongs to element 0 and CAP_PDKILL to element 1:

cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL);

Providing several rights that belongs to the same array's element this way is
correct, but is not advised. It should only be used for aliases definition.

This commit also breaks compatibility with some existing Capsicum system calls,
but I see no other way to do that. This should be fine as Capsicum is still
experimental and this change is not going to 9.x.

Sponsored by: The FreeBSD Foundation

In looking at block layouts as part of fixing filesystem block
allocations under low free-space conditions (-r254995), determine
that old block-preference search order used before -r249782 worked
a bit better. This change reverts to that block-preference search order.

MFC after: 2 weeks

A performance problem was reported in PR kern/181226:

I have 25TB Dell PERC 6 RAID5 array. When it becomes almost
full (10-20GB free), processes which write data to it start
eating 100% CPU and write speed drops below 1MB/sec (normally
to gives 400MB/sec). The revision at which it first became
apparent was http://svnweb.freebsd.org/changeset/base/249782.

The offending change reserved an area in each cylinder group to
store metadata. The new algorithm attempts to save this area for
metadata and allows its use for non-metadata only after all the
data areas have been exhausted. The size of the reserved area
defaults to half of minfree, so the filesystem reports full before
the data area can completely fill. However, in this report, the
filesystem has had minfree reduced to 1% thus forcing the metadata
area to be used for data. As the filesystem approached full, it
had only metadata areas left to allocate. The result was that
every block allocation had to scan summary data for 30,000 cylinder
groups before falling back to searching up to 30,000 metadata areas.

The fix is to give up on saving the metadata areas once the free
space reserve drops below 2%. The effect of this change is to use
the old algorithm of just accepting the first available block that
we find. Since most filesystems use the default 5% minfree, this
will have no effect on their operation. For those that want to push
to the limit, they will get their crappy block placements quickly.

Submitted by: Dmitry Sivachenko
Fix Tested by: Dmitry Sivachenko
PR: kern/181226
MFC after: 2 weeks

Take a very small step toward the Century of the Anchovy by increasing the
time dirhash entries stay in memory before being considered for eviction to
1 minute.

Expand the use of stat(2) flags to allow storing some Windows/DOS
and CIFS file attributes as BSD stat(2) flags.

This work is intended to be compatible with ZFS, the Solaris CIFS
server's interaction with ZFS, somewhat compatible with MacOS X,
and of course compatible with Windows.

The Windows attributes that are implemented were chosen based on
the attributes that ZFS already supports.

The summary of the flags is as follows:

UF_SYSTEM: Command line name: "system" or "usystem"
ZFS name: XAT_SYSTEM, ZFS_SYSTEM
Windows: FILE_ATTRIBUTE_SYSTEM

This flag means that the file is used by the
operating system. FreeBSD does not enforce any
special handling when this flag is set.

UF_SPARSE: Command line name: "sparse" or "usparse"
ZFS name: XAT_SPARSE, ZFS_SPARSE
Windows: FILE_ATTRIBUTE_SPARSE_FILE

This flag means that the file is sparse. Although
ZFS may modify this in some situations, there is
not generally any special handling for this flag.

UF_OFFLINE: Command line name: "offline" or "uoffline"
ZFS name: XAT_OFFLINE, ZFS_OFFLINE
Windows: FILE_ATTRIBUTE_OFFLINE

This flag means that the file has been moved to
offline storage. FreeBSD does not have any special
handling for this flag.

UF_REPARSE: Command line name: "reparse" or "ureparse"
ZFS name: XAT_REPARSE, ZFS_REPARSE
Windows: FILE_ATTRIBUTE_REPARSE_POINT

This flag means that the file is a Windows reparse
point. ZFS has special handling code for reparse
points, but we don't currently have the other
supporting infrastructure for them.

UF_HIDDEN: Command line name: "hidden" or "uhidden"
ZFS name: XAT_HIDDEN, ZFS_HIDDEN
Windows: FILE_ATTRIBUTE_HIDDEN

This flag means that the file may be excluded from
a directory listing if the application honors it.
FreeBSD has no special handling for this flag.

The name and bit definition for UF_HIDDEN are
identical to the definition in MacOS X.

UF_READONLY: Command line name: "urdonly", "rdonly", "readonly"
ZFS name: XAT_READONLY, ZFS_READONLY
Windows: FILE_ATTRIBUTE_READONLY

This flag means that the file may not written or
appended, but its attributes may be changed.

ZFS currently enforces this flag, but Illumos
developers have discussed disabling enforcement.

The behavior of this flag is different than MacOS X.
MacOS X uses UF_IMMUTABLE to represent the DOS
readonly permission, but that flag has a stronger
meaning than the semantics of DOS readonly permissions.

UF_ARCHIVE: Command line name: "uarch", "uarchive"
ZFS_NAME: XAT_ARCHIVE, ZFS_ARCHIVE
Windows name: FILE_ATTRIBUTE_ARCHIVE

The UF_ARCHIVED flag means that the file has changed and
needs to be archived. The meaning is same as
the Windows FILE_ATTRIBUTE_ARCHIVE attribute, and
the ZFS XAT_ARCHIVE and ZFS_ARCHIVE attribute.

msdosfs and ZFS have special handling for this flag.
i.e. they will set it when the file changes.

sys/param.h: Bump __FreeBSD_version to 1000047 for the
addition of new stat(2) flags.

chflags.1: Document the new command line flag names
(e.g. "system", "hidden") available to the
user.

ls.1: Reference chflags(1) for a list of file flags
and their meanings.

strtofflags.c: Implement the mapping between the new
command line flag names and new stat(2)
flags.

chflags.2: Document all of the new stat(2) flags, and
explain the intended behavior in a little
more detail. Explain how they map to
Windows file attributes.

Different filesystems behave differently
with respect to flags, so warn the
application developer to take care when
using them.

zfs_vnops.c: Add support for getting and setting the
UF_ARCHIVE, UF_READONLY, UF_SYSTEM, UF_HIDDEN,
UF_REPARSE, UF_OFFLINE, and UF_SPARSE flags.

All of these flags are implemented using
attributes that ZFS already supports, so
the on-disk format has not changed.

ZFS currently doesn't allow setting the
UF_REPARSE flag, and we don't really have
the other infrastructure to support reparse
points.

msdosfs_denode.c,
msdosfs_vnops.c: Add support for getting and setting
UF_HIDDEN, UF_SYSTEM and UF_READONLY
in MSDOSFS.

It supported SF_ARCHIVED, but this has been
changed to be UF_ARCHIVE, which has the same
semantics as the DOS archive attribute instead
of inverse semantics like SF_ARCHIVED.

After discussion with Bruce Evans, change
several things in the msdosfs behavior:

Use UF_READONLY to indicate whether a file
is writeable instead of file permissions, but
don't actually enforce it.

Refuse to change attributes on the root
directory, because it is special in FAT
filesystems, but allow most other attribute
changes on directories.

Don't set the archive attribute on a directory
when its modification time is updated.
Windows and DOS don't set the archive attribute
in that scenario, so we are now bug-for-bug
compatible.

smbfs_node.c,
smbfs_vnops.c: Add support for UF_HIDDEN, UF_SYSTEM,
UF_READONLY and UF_ARCHIVE in SMBFS.

This is similar to changes that Apple has
made in their version of SMBFS (as of
smb-583.8, posted on opensource.apple.com),
but not quite the same.

We map SMB_FA_READONLY to UF_READONLY,
because UF_READONLY is intended to match
the semantics of the DOS readonly flag.
The MacOS X code maps both UF_IMMUTABLE
and SF_IMMUTABLE to SMB_FA_READONLY, but
the immutable flags have stronger meaning
than the DOS readonly bit.

stat.h: Add definitions for UF_SYSTEM, UF_SPARSE,
UF_OFFLINE, UF_REPARSE, UF_ARCHIVE, UF_READONLY
and UF_HIDDEN.

The definition of UF_HIDDEN is the same as
the MacOS X definition.

Add commented-out definitions of
UF_COMPRESSED and UF_TRACKED. They are
defined in MacOS X (as of 10.8.2), but we
do not implement them (yet).

ufs_vnops.c: Add support for getting and setting
UF_ARCHIVE, UF_HIDDEN, UF_OFFLINE, UF_READONLY,
UF_REPARSE, UF_SPARSE, and UF_SYSTEM in UFS.
Alphabetize the flags that are supported.

These new flags are only stored, UFS does
not take any action if the flag is set.

Sponsored by: Spectra Logic
Reviewed by: bde (earlier version)

This bug fix is in a code path in rename taken when there is a
collision between a rename and an open system call for the same
target file. Here, rename releases its vnode references, waits for
the open to finish, and then restarts by reacquiring its needed
vnode locks. In this case, rename was unlocking but failing to
release its reference to one of its held vnodes. The effect was
that even after all the actual references to the vnode had gone,
the vnode still showed active references. For files that had been
removed, their space was not reclaimed until the filesystem was
forcibly unmounted.

This bug manifested itself in the Postgres server which would
leak/lose hundreds of files per day amounting to many gigabytes of
disk space. This bug required shutting down Postgres, forcibly
unmounting its filesystem, remounting its filesystem and restarting
Postgres every few days to recover the lost space.

Reported by: Dan Thomas and Palle Girgensohn
Bug-fix by: kib
Tested by: Dan Thomas and Palle Girgensohn
MFC after: 2 weeks

With the addition of journalled soft updates, the "newblk" structures
persist much longer than previously. Historically we had at most 100
entries; now the count may reach a million. With the increased count
we spent far too much time looking them up in the grossly undersized
newblk hash table. Configure the newblk hash table to accurately reflect
the number of entries that it must index.

Reviewed by: kib
Tested by: Peter Holm
MFC after: 2 weeks

To better understand performance problems with journalled soft updates,
we need to collect the highest level of allocation for each of the
different soft update dependency structures. This change collects these
statistics and makes them available using `sysctl debug.softdep.highuse'.

Reviewed by: kib
Tested by: Peter Holm
MFC after: 2 weeks

Update to comments describing block allocation policy.

Submitted by: Bruce Evans

Only copy as much bytes as there in superblock, instead of the full
block copy, when copying the superblock into the snapshot. UFS1 does
not align superblock on the block boundary, and bcopy runs off the end
of the buffer.

Reported by: Andre Albsmeier <Andre.Albsmeier@siemens.com>
Reviewed by: mckusick
Sponsored by: The FreeBSD Foundation
MFC after: 1 week

Change i_gen in UFS to an unsigned type.

Missing type change from r252435.

This fixes a "Stale NFS file handle" error.

Reported by: Claude Bisson
Tested by: Claude Bisson
Pointed hat: pfg

There are several code sequences like
vfs_busy(mp);
vfs_write_suspend(mp);
which are problematic if other thread starts unmount between two
calls. The unmount starts a write, while vfs_write_suspend() drain
writers. On the other hand, unmount drains busy references, causing
the deadlock.

Add a flag argument to vfs_write_suspend and require the callers of it
to specify VS_SKIP_UNMOUNT flag, when the call is performed not in the
mount path, i.e. the covered vnode is not locked. The suspension is
not attempted if VS_SKIP_UNMOUNT is specified and unmount is in
progress.

Reported and tested by: Andreas Longwitz <longwitz@incore.de>
Sponsored by: The FreeBSD Foundation
MFC after: 3 weeks

Make better use of metadata area by avoiding using it for data blocks
that no should no longer immediately follow their indirect blocks.

MFC after: 2 weeks

Style fix: spaces.

Cleanup the incomplete revert.

Reported by: bde
MFC after: 4 weeks

Change i_gen in UFS to an unsigned type.

Revert the simplification of the i_gen calculation.
It is still a good idea to avoid zero values and for the case
of old filesystems there is probably no advantage in using
the complete 32 bits anyways.

Discussed with: bde
MFC after: 4 weeks

Change i_gen in UFS to an unsigned type.

Further simplify the i_gen calculation for older disks.
Having a zero here is not really a problem and this is more
similar to what is done in newfs_random().

Reported by: Xin Li
MFC after: 4 weeks

Don't assume that UFS on-disk format of a directory is the same as
defined by <sys/dirent.h>

Always start parsing at DIRBLKSIZ aligned offset, skip first entries if
uio_offset is not DIRBLKSIZ aligned. Return EINVAL if buffer is too
small for single entry.

Preallocate buffer for cookies. Cookies will be replaced with d_off
field in struct dirent at later point.

Skip entries with zero inode number.

Stop mangling dirent in ufs_extattr_iterate_directory().

Reviewed by: kib
Sponsored by: Google Summer Of Code 2011

Change i_gen in UFS to an unsigned type.

Missed format specifier.

Reported by: mdf
MFC after: 4 weeks

Change i_gen in UFS to an unsigned type.

In UFS, i_gen is a random generated value and there is not way for
it to be negative. Actually, the value of i_gen is just used to
match bit patterns and it is of not consequence if the values are
signed or not.

Following other filesystems, set it to unsigned and use it as such,

Discussed by: mckusick
Reviewed by: mckusick (previous version)
MFC after: 4 weeks

- Convert the bufobj lock to rwlock.
- Use a shared bufobj lock in getblk() and inmem().
- Convert softdep's lk to rwlock to match the bufobj lock.
- Move INFREECNT to b_flags and protect it with the buf lock.
- Remove unnecessary locking around bremfree() and BKGRDINPROG.

Sponsored by: EMC / Isilon Storage Division
Discussed with: mckusick, kib, mdf

Properly spell sentinel (missed in 250891)
No functional changes.

Spotted by: Navdeep Parhar and Alexey Dokuchaev
MFC after: 2 weeks

Add missing buffer releases (brelse) after bread calls that return
an error. One could argue that returning a buffer even when it is
not valid is incorrect, but bread has always returned a buffer
valid or not.

Reviewed by: kib
MFC after: 2 weeks

Add missing 28th element to softdep types name array.

Found by: Coverity Scan, CID 1007621
Reviewed by: kib
MFC after: 2 weeks

Null a pointer after it is freed so that when it is returned
the return value is NULL. Based on the returned flags, the
return value should never be inspected in the case where NULL
is returned, but it is good coding practice not to return a
pointer to freed memory.

Found by: Coverity Scan, CID 1006096
Reviewed by: kib
MFC after: 2 weeks

Remove a bogus check for a NULL buffer pointer.
Add a KASSERT that it is not NULL.

Found by: Coverity Scan, CID 1009114
Reviewed by: kib
MFC after: 2 weeks

Properly spell sentinel (not sintenel or sentinal).
No functional changes.

Spotted by: kib
MFC after: 2 weeks

Fix several typos

PR: kern/176054
Submitted by: Christoph Mallon <christoph.mallon@gmx.de>
MFC after: 3 days

- Correct mispellings of the word occurrence

Submitted by: Christoph Mallon <christoph.mallon@gmx.de> (via private mail)

Prepare to replace the buf splay with a trie:

- Don't insert BKGRDMARKER bufs into the splay or dirty/clean buf lists.
No consumers need to find them there and it complicates the tree.
These flags are all FFS specific and could be moved out of the buf
cache.
- Use pbgetvp() and pbrelvp() to associate the background and journal
bufs with the vp. Not only is this much cheaper it makes more sense
for these transient bufs.
- Fix the assertions in pbget* and pbrel*. It's not safe to check list
pointers which were never initialized. Use the BX flags instead. We
also check B_PAGING in reassignbuf() so this should cover all cases.

Discussed with: kib, mckusick, attilio
Sponsored by: EMC / Isilon Storage Division

The code in clear_remove() and clear_inodedeps() skips one entry
in the pagedep and inodedep hash tables. An entry in the table is
skipped because 'pagedep_hash' and 'inodedep_hash' hold the size
of the hash tables - 1.

The chance that this would have any operational failure is extremely
unlikely. These funtions only need to find a single entry and are
only called when there are too many entries. The chance that they
would fail because all the entries are on the single skipped hash
chain are remote.

Submitted by: Pedro Martelletto
Reviewed by: kib
MFC after: 2 weeks

The purpose of this change to the FFS layout policy is to reduce the
running time for a full fsck. It also reduces the random access time
for large files and speeds the traversal time for directory tree walks.

The key idea is to reserve a small area in each cylinder group
immediately following the inode blocks for the use of metadata,
specifically indirect blocks and directory contents. The new policy
is to preferentially place metadata in the metadata area and
everything else in the blocks that follow the metadata area.

The size of this area can be set when creating a filesystem using
newfs(8) or changed in an existing filesystem using tunefs(8).
Both utilities use the `-k held-for-metadata-blocks' option to
specify the amount of space to be held for metadata blocks in each
cylinder group. By default, newfs(8) sets this area to half of
minfree (typically 4% of the data area).

This work was inspired by a paper presented at Usenix's FAST '13:
www.usenix.org/conference/fast13/ffsck-fast-file-system-checker

Details of this implementation appears in the April 2013 of ;login:
www.usenix.org/publications/login/april-2013-volume-38-number-2.
A copy of the April 2013 ;login: paper can also be downloaded
from: www.mckusick.com/publications/faster_fsck.pdf.

Reviewed by: kib
Tested by: Peter Holm
MFC after: 4 weeks

When renaming a directory from one parent directory to another,
we need to call ufs_checkpath() to walk from our new location to
the root of the filesystem to ensure that we do not encounter
ourselves along the way. Until now, we accomplished this by reading
the ".." entries of each directory in our path until we reached
the root (or encountered an error). This change tries to avoid the
I/O of reading the ".." entries by first looking them up in the
name cache and only doing the I/O when the name cache lookup fails.

Reviewed by: kib
Tested by: Peter Holm
MFC after: 4 weeks

UFS support of the unmapped i/o for the user data buffers.

Sponsored by: The FreeBSD Foundation
Tested by: pho, scottl, jhb, bf

Do not remap usermode pages into KVA for physio.

Sponsored by: The FreeBSD Foundation
Tested by: pho

Remove negative name cache entry pointing to the target name, which
could be instantiated while tdvp was unlocked.

Reported by: Rick Miller <vmiller at hostileadmin com>
Tested by: pho
MFC after: 1 week

Some style fixes.

Sponsored by: The FreeBSD Foundation

Add currently unused flag argument to the cluster_read(),
cluster_write() and cluster_wbuild() functions. The flags to be
allowed are a subset of the GB_* flags for getblk().

Sponsored by: The FreeBSD Foundation
Tested by: pho

Switch the vm_object mutex to be a rwlock. This will enable in the
future further optimizations where the vm_object lock will be held
in read mode most of the time the page cache resident pool of pages
are accessed for reading purposes.

The change is mostly mechanical but few notes are reported:
* The KPI changes as follow:
- VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK()
- VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK()
- VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK()
- VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED()
(in order to avoid visibility of implementation details)
- The read-mode operations are added:
VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(),
VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED()
* The vm/vm_pager.h namespace pollution avoidance (forcing requiring
sys/mutex.h in consumers directly to cater its inlining functions
using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h
consumers now must include also sys/rwlock.h.
* zfs requires a quite convoluted fix to include FreeBSD rwlocks into
the compat layer because the name clash between FreeBSD and solaris
versions must be avoided.
At this purpose zfs redefines the vm_object locking functions
directly, isolating the FreeBSD components in specific compat stubs.

The KPI results heavilly broken by this commit. Thirdy part ports must
be updated accordingly (I can think off-hand of VirtualBox, for example).

Sponsored by: EMC / Isilon storage division
Reviewed by: jeff
Reviewed by: pjd (ZFS specific review)
Discussed with: alc
Tested by: pho

The softdep freeblks workitem might hold a reference on the dquot.
Current dqflush() panics when a dquot with with non-zero refcount is
encountered. The situation is possible, because quotas are turned off
before softdep workitem queue if flushed, due to the quota file writes
might create softdep workitems.

Make the encountering an active dquot in dqflush() not fatal, return
the error from quotaoff() instead. Ignore the quotaoff() failures
when ffs_flushfiles() is called in the course of softdep_flushfiles()
loop, until the last iteration. At the last loop, the quotas must be
closed, and because SU workitems should be already flushed, the
references to dquot are gone.

Sponsored by: The FreeBSD Foundation
Reported and tested by: pho
Reviewed by: mckusick
MFC after: 2 weeks

An inode block must not be blockingly read while cg block is owned.
The order is inode buffer lock -> snaplk -> cg buffer lock, reversing
the order causes deadlocks.

Inode block must not be written while cg block buffer is owned. The
FFS copy on write needs to allocate a block to copy the content of the
inode block, and the cylinder group selected for the allocation might
be the same as the owned cg block. The reserved block detection code
in the ffs_copyonwrite() and ffs_bp_snapblk() is unable to detect the
situation, because the locked cg buffer is not exposed to it.

In order to maintain the dependency between initialized inode block
and the cg_initediblk pointer, look up the inode buffer in
non-blocking mode. If succeeded, brelse cg block, initialize the inode
block and write it. After the write is finished, reread cg block and
update the cg_initediblk.

If inode block is already locked by another thread, let the another
thread initialize it. If another thread raced with us after we
started writing inode block, the situation is detected by an update of
cg_initediblk. Note that double-initialization of the inode block is
harmless, the block cannot be used until cg_initediblk is incremented.

Sponsored by: The FreeBSD Foundation
In collaboration with: pho
Reviewed by: mckusick
MFC after: 1 month
X-MFC-note: after r246877

The UFS2 filesystem allocates new blocks of inodes as they are needed.
When a cylinder group runs short of inodes, a new block for inodes is
allocated, zero'ed, and written to the disk. The zero'ed inodes must
be on the disk before the cylinder group can be updated to claim them.
If the cylinder group claiming the new inodes were written before the
zero'ed block of inodes, the system could crash with the filesystem in
an unrecoverable state.

Rather than adding a soft updates dependency to ensure that the new
inode block is written before it is claimed by the cylinder group
map, we just do a barrier write of the zero'ed inode block to ensure
that it will get written before the updated cylinder group map can
be written. This change should only slow down bulk loading of newly
created filesystems since that is the primary time that new inode
blocks need to be created.

Reported by: Robert Watson
Reviewed by: kib
Tested by: Peter Holm

Fix several unsafe pointer dereferences in the buffered_write()
function, implementing the sysctl vfs.ffs.set_bufoutput (not used in
the tree yet).

- The current directory vnode dereference is unsafe since fd_cdir
could be changed and unreferenced, lock the filedesc around and vref
the fd_cdir.
- The VTOI() conversion of the fd_cdir is unsafe without first
checking that the vnode is indeed from an FFS mount, otherwise
the code dereferences a random memory.
- The cdir could be reclaimed from under us, lock it around the
checks.
- The type of the fp vnode might be not a disk, or it might have
changed while the thread was in flight, check the type.

Reviewed and tested by: mckusick
MFC after: 2 weeks

Remove unused MAXSYMLINKLEN macro.

Reviewed by: mckusick
PR: kern/175794
MFC after: 1 week

UFS: Remove dead assignment.

Submitted by: Christoph Mallon
MFC after: 3 days

For UFS2 i_blocks is unsigned. The current "sanity" check that it
has gone below zero after the blocks in its inode are freed is a
no-op which the compiler fails to warn about because of the use of
the DIP macro. Change the sanity check to compare the number of
blocks being freed against the value i_blocks. If the number of
blocks being freed exceeds i_blocks, just set i_blocks to zero.

Reported by: Pedro Giffuni (pfg@)
MFC after: 2 weeks

Add flags argument to vfs_write_resume() and remove
vfs_write_resume_flags().

Sponsored by: The FreeBSD Foundation

The process_deferred_inactive() function locks the vnodes of the ufs
mount, which means that is must not be called while the snaplock is
owned. The vfs_write_resume(9) does call the function as the
VFS_SUSP_CLEAN() method, which is too early and falls into the region
still protected by snaplock.

Add yet another flag for the vfs_write_resume_flags() to avoid calling
suspension cleanup handler after the suspend is lifted, and use it in
the ffs_snapshot() call to vfs_write_resume.

Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks

Make it possible to atomically resume writes on the mount and account
the write start, by adding a variation of the vfs_write_resume(9)
which accepts flags.

Use the new function to prevent a deadlock between parallel suspension
and snapshotting a UFS mount. The ffs_snapshot() code performed
vfs_write_resume() followed by vn_start_write() while owning the
snaplock. If the suspension intervene between resume and
vn_start_write(), the deadlock occured after the suspending thread
tried to lock the snaplock, most typically during the write in the
ffs_copyonwrite().

Reported and tested by: Andreas Longwitz <longwitz@incore.de>
Reviewed by: mckusick
MFC after: 2 weeks
X-MFC-note: make the vfs_write_resume(9) function a macro after the MFC,
in HEAD

Fixup r218424: uio_yield() was scaling directly to userland priority.
When kern_yield() was introduced with the possibility to specify
a new priority, the behaviour changed by not lowering priority at all
in the consumers, making the yielding mechanism highly ineffective for
high priority kthreads like bufdaemon, syncer, vlrudaemon, etc.
There are no evidences that consumers could bear with such change in
semantic and this situation could finally lead to bugs similar to the
ones fixed in r244240.
Re-specify userland pri for kthreads involved.

Tested by: pho
Reviewed by: kib, mdf
MFC after: 1 week

Fix a typo, resulting in the NULL pointer dereference.

Reported and tested by: pho
Sponsored by: The FreeBSD Foundation
MFC after: 3 days

r16312 is not any longer real since many years (likely since when VFS
received granular locking) but the comment present in UFS has been
copied all over other filesystems code incorrectly for several times.

Removes comments that makes no sense now.

Reviewed by: kib
MFC after: 3 days

Fix build of kdump(1).

Add UFS writesuspension mechanism, designed to allow userland processes
to modify on-disk metadata for filesystems mounted for write.

Reviewed by: kib, mckusick
Sponsored by: FreeBSD Foundation

- Fix a truncation bug with softdep journaling that could leak blocks on
crash. When truncating a file that never made it to disk we use the
canceled allocation dependencies to hold the journal records until
the truncation completes. Previously allocdirect dependencies on
the id_bufwait list were not considered and their journal space
could expire before the bitmaps were written. Cancel them and attach
them to the freeblks as we do for other allocdirects.
- Add KTR traces that were used to debug this problem.
- When adding jsegdeps, always use jwork_insert() so we don't have more
than one segdep on a given jwork list.

Sponsored by: EMC / Isilon Storage Division

- Fix a bug that has existed since the original softdep implementation.
When a background copy of a cg is written we complete any work associated
with that bmsafemap. If new work has been added to the non-background
copy of the buffer it will be completed before the next write happens.
The solution is to do the rollbacks when we make the copy so only those
dependencies that were present at the time of writing will be completed
when the background write completes. This would've resulted in various
bitmap related corruptions and panics. It also would've expired journal
entries early causing journal replay to miss some records.

MFC after: 2 weeks

Complete MPSAFE VFS interface and remove MNTK_MPSAFE flag.
Porters should refer to __FreeBSD_version 1000021 for this change as
it may have happened at the same timeframe.

- Correct rev 242734, segments can sometimes get stuck. Be a bit more
defensive with segment state.

Reported by: b. f. <bf1783@googlemail.com>

- Implement BIO_FLUSH support around journal entries. This will not 100%
solve power loss problems with dishonest write caches. However, it
should improve the situation and force a full fsck when it is unable
to resolve with the journal.
- Resolve a case where the journal could wrap in an unsafe way causing
us to prematurely lose journal entries in very specific scenarios.

Discussed with: mckusick
MFC after: 1 month

When a file is first being written, the dynamic block reallocation
(implemented by ffs_reallocblks_ufs[12]) relocates the file's blocks
so as to cluster them together into a contiguous set of blocks on
the disk.

When the cluster crosses the boundary into the first indirect block,
the first indirect block is initially allocated in a position
immediately following the last direct block. Block reallocation
would usually destroy locality by moving the indirect block out of
the way to keep the data blocks contiguous. This change compensates
for this problem by noting that the first indirect block should be
left immediately following the last direct block. It then tries
to start a new cluster of contiguous blocks (referenced by the
indirect block) immediately following the indirect block.

We should also do this for other indirect block boundaries, but it
is only important for the first one.

Suggested by: Bruce Evans
MFC: 2 weeks

- In cancel_mkdir_dotdot don't panic if the inodedep is not available. If
the previous diradd had already finished it could have been reclaimed
already. This would only happen under heavy dependency pressure.

Reported by: Andrey Zonov <zont@FreeBSD.org>
Discussed with: mckusick
MFC after: 1 week

The r241025 fixed the case when a binary, executed from nullfs mount,
was still possible to open for write from the lower filesystem. There
is a symmetric situation where the binary could already has file
descriptors opened for write, but it can be executed from the nullfs
overlay.

Handle the issue by passing one v_writecount reference to the lower
vnode if nullfs vnode has non-zero v_writecount. Note that only one
write reference can be donated, since nullfs only keeps one use
reference on the lower vnode. Always use the lower vnode v_writecount
for the checks.

Introduce the VOP_GET_WRITECOUNT to read v_writecount, which is
currently always bypassed to the lower vnode, and VOP_ADD_WRITECOUNT
to manipulate the v_writecount value, which manages a single bypass
reference to the lower vnode. Caling the VOPs instead of directly
accessing v_writecount provide the fix described in the previous
paragraph.

Tested by: pho
MFC after: 3 weeks

Fix problem with geom_label(4) not recognizing UFS labels on filesystems
extended using growfs(8). The problem here is that geom_label checks if
the filesystem size recorded in UFS superblock is equal to the provider
(i.e. device) size. This check cannot be removed due to backward
compatibility. On the other hand, in most cases growfs(8) cannot set
fs_size in the superblock to match the provider size, because, differently
from newfs(8), it cannot recompute cylinder group sizes.

To fix this problem, add another superblock field, fs_providersize, used
only for this purpose. The geom_label(4) will attach if either fs_size
(filesystem created with newfs(8)) or fs_providersize (filesystem expanded
using growfs(8)) matches the device size.

PR: kern/165962
Reviewed by: mckusick
Sponsored by: FreeBSD Foundation

Fix two problems that caused instant panic when the device mounted
with softupdates went away. Note that this does not fix the problem
entirely; I'm committing it now to make it easier for someone to pick
up the work.

Reviewed by: mckusick

Remove the support for using non-mpsafe filesystem modules.

In particular, do not lock Giant conditionally when calling into the
filesystem module, remove the VFS_LOCK_GIANT() and related
macros. Stop handling buffers belonging to non-mpsafe filesystems.

The VFS_VERSION is bumped to indicate the interface change which does
not result in the interface signatures changes.

Conducted and reviewed by: attilio
Tested by: pho

Fix up kernel sources to be ready for a 64-bit ino_t.

Original code by: Gleb Kurtsou

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

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

After the PHYS_TO_VM_PAGE() function was de-inlined, the main reason
to pull vm_param.h was removed. Other big dependency of vm_page.h on
vm_param.h are PA_LOCK* definitions, which are only needed for
in-kernel code, because modules use KBI-safe functions to lock the
pages.

Stop including vm_param.h into vm_page.h. Include vm_param.h
explicitely for the kernel code which needs it.

Suggested and reviewed by: alc
MFC after: 2 weeks

Use NULL instead of 0 for pointers

Extend the KPI to lock and unlock f_offset member of struct file. It
now fully encapsulates all accesses to f_offset, and extends f_offset
locking to other consumers that need it, in particular, to lseek() and
variants of getdirentries().

Ensure that on 32bit architectures f_offset, which is 64bit quantity,
always read and written under the mtxpool protection. This fixes
apparently easy to trigger race when parallel lseek()s or lseek() and
read/write could destroy file offset.

The already broken ABI emulations, including iBCS and SysV, are not
converted (yet).

Tested by: pho
No objections from: jhb
MFC after: 3 weeks

Fix unbounded-length malloc, controlled from usermode. The added check
is performed before exact size of the buffer is calculated, but the
buffer cannot have size greater then the total space allocated for
extended attributes. The existing check is executing with precise
size, but it is too late, since buffer needs to be allocated in
advance.

Also, adapt to uio_resid being of ssize_t type. Use lblktosize instead of
multiplying by fs block size by hand as well.

Reported and tested by: pho
MFC after: 1 week

In softdep_setup_inomapdep() we may have to allocate both inodedep
and bmsafemap dependency structures in inodedep_lookup() and
bmsafemap_lookup() respectively. The setup of these structures must
be done while holding the soft-dependency mutex. If the inodedep is
allocated first, it may be freed in the I/O completion callback when
the mutex is released to allocate the bmsafemap. If the bmsafemap is
allocated first, it may be freed in the I/O completion callback when
the mutex is released to allocate the inodedep.

To resolve this problem, bmsafemap_lookup has had a parameter added
that allows a pre-malloc'ed bmsafemap to be passed in so that it does
not need to release the mutex to create a new bmsafemap. The
softdep_setup_inomapdep() routine pre-malloc's a bmsafemap dependency
before acquiring the mutex and starting to build the inodedep with a
call to inodedep_lookup(). The subsequent call to bmsafemap_lookup()
is passed this pre-allocated bmsafemap entry so that it need not
release the mutex if it needs to create a new one.

Reported by: Peter Holm
Tested by: Peter Holm
MFC after: 1 week

Enable vn_io_fault() lock avoidance for UFS.

Tested by: pho
MFC after: 2 months

Implement SEEK_HOLE/SEEK_DATA for UFS.

MFC after: 2 weeks

Add missing `continue' statement at end of case.

Found by: Kevin Lo (kevlo@)
MFC after: 1 week

Remove unused thread argument from ufs_extattr_uepm_lock()/ufs_extattr_uepm_unlock().

Fix build.

Remove unused thread argument from clear_inodeps() and clear_remove().

Remove unused thread argument to vrecycle().

Reviewed by: kib

Remove unused thread argument from vtruncbuf().

Reviewed by: kib

Fix use-after-free introduced in r234036.

Reviewed by: mckusick
Tested by: pho

This update uses the MNT_VNODE_FOREACH_ACTIVE interface that loops
over just the active vnodes associated with a mount point to replace
MNT_VNODE_FOREACH_ALL in the vfs_msync, ffs_sync_lazy, and qsync
routines.

The vfs_msync routine is run every 30 seconds for every writably
mounted filesystem. It ensures that any files mmap'ed from the
filesystem with modified pages have those pages queued to be
written back to the file from which they are mapped.

The ffs_lazy_sync and qsync routines are run every 30 seconds for
every writably mounted UFS/FFS filesystem. The ffs_lazy_sync routine
ensures that any files that have been accessed in the previous
30 seconds have had their access times queued for updating in the
filesystem. The qsync routine ensures that any files with modified
quotas have those quotas queued to be written back to their
associated quota file.

In a system configured with 250,000 vnodes, less than 1000 are
typically active at any point in time. Prior to this change all
250,000 vnodes would be locked and inspected twice every minute
by the syncer. For UFS/FFS filesystems they would be locked and
inspected six times every minute (twice by each of these three
routines since each of these routines does its own pass over the
vnodes associated with a mount point). With this change the syncer
now locks and inspects only the tiny set of vnodes that are active.

Reviewed by: kib
Tested by: Peter Holm
MFC after: 2 weeks

The part about exec atime no longer applies in the comment.

Pointed out by: bde

Replace the MNT_VNODE_FOREACH interface with MNT_VNODE_FOREACH_ALL.
The primary changes are that the user of the interface no longer
needs to manage the mount-mutex locking and that the vnode that
is returned has its mutex locked (thus avoiding the need to check
to see if its is DOOMED or other possible end of life senarios).

To minimize compatibility issues for third-party developers, the
old MNT_VNODE_FOREACH interface will remain available so that this
change can be MFC'ed to 9. Following the MFC to 9, MNT_VNODE_FOREACH
will be removed in head.

The reason for this update is to prepare for the addition of the
MNT_VNODE_FOREACH_ACTIVE interface that will loop over just the
active vnodes associated with a mount point (typically less than
1% of the vnodes associated with the mount point).

Reviewed by: kib
Tested by: Peter Holm
MFC after: 2 weeks

Export vinactive() from kern/vfs_subr.c (e.g., make it no longer
static and declare its prototype in sys/vnode.h) so that it can be
called from process_deferred_inactive() (in ufs/ffs/ffs_snapshot.c)
instead of the body of vinactive() being cut and pasted into
process_deferred_inactive().

Reviewed by: kib
MFC after: 2 weeks

- Return EPERM from ufs_setattr() when an user without PRIV_VFS_SYSFLAGS
privilege attempts to toggle SF_SETTABLE flags.
- Use the '^' operator in the SF_SNAPSHOT anti-toggling check.

Flags are now stored to ip->i_flags in one place after all checks.

Submitted by: bde

Fix panic in ffs_reload(), which may happen when read-only filesystem
gets resized and then reloaded.

Reviewed by: kib, mckusick (earlier version)
Sponsored by: The FreeBSD Foundation

Drop an unnecessary setting of si_mountpt when updating a UFS mount point.
Clearly it must have been set when the mount was done.

Reviewed by: kib

Add a check for unsupported file flags to ufs_setattr().

Discussed with: bde
MFC after: 2 weeks

A file cannot be deallocated until its last name has been removed
and it is no longer referenced by a user process. The inode for a
file whose name has been removed, but is still referenced at the
time of a crash will still be allocated in the filesystem, but will
have no references (e.g., they will have no names referencing them
from any directory).

With traditional soft updates these unreferenced inodes will be
found and reclaimed when the background fsck is run. When using
journaled soft updates, the kernel must keep track of these inodes
so that it can find and reclaim them during the cleanup process.
Their existence cannot be stored in the journal as the journal only
handles short-term events, and they may persist for days. So, they
are tracked by keeping them in a linked list whose head pointer is
stored in the superblock. The journal tracks them only until their
linked list pointers have been commited to disk. Part of the cleanup
process involves traversing the list of unreferenced inodes and
reclaiming them.

This bug was triggered when confusion arose in the commit steps
of keeping the unreferenced-inode linked list coherent on disk.
Notably, a race between the link() system call adding a link-count
to a file and the unlink() system call removing a link-count to
the file. Here if the unlink() ran after link() had looked up
the file but before link() had incremented the link-count of the
file, the file's link-count would drop to zero before the link()
incremented it back up to one. If the file was referenced by a
user process, the first transition through zero made it appear
that it should be added to the unreferenced-inode list when in
fact it should not have been added. If the new name created by
link() was deleted within a few seconds (with the file still
referenced by a user process) it would legitimately be a candidate
for addition to the unreferenced-inode list. The result was that
there were two attempts to add the same inode to the unreferenced-inode
list which scrambled the unreferenced-inode list's pointers leading
to a panic. The fix is to detect and avoid the false attempt at
adding it to the unreferenced-inode list by having the link()
system call check to see if the link count is zero before it
increments it. If it is, the link() fails with ENOENT (showing that
it has failed the link()/unlink() race).

While tracking down this bug, we have added additional assertions
to detect the problem sooner and also simplified some of the code.

Reported by: Kirk Russell
Fix submitted by: Jeff Roberson
Tested by: Peter Holm
PR: kern/159971
MFC (to 9 only): 2 weeks

- Use more natural ip->i_flags instead of vap->va_flags in the final
flags check.
- Add a comment for the immutable/append check done after handling of
the flags.
- Style improvements.

No functional change intended.

Submitted by: bde
MFC after: 2 weeks

A refinement of change 232351 to avoid a race with a forcible unmount.
While we have a snapshot vnode unlocked to avoid a deadlock with another
inode in the same inode block being updated, the filesystem containing
it may be forcibly unmounted. When that happens the snapshot vnode is
revoked. We need to check for that condition and fail appropriately.

This change will be included along with 232351 when it is MFC'ed to 9.

Spotted by: kib
Reviewed by: kib

Keep track of the mount point associated with a special device
to enable the collection of counts of synchronous and asynchronous
reads and writes for its associated filesystem. The counts are
displayed using `mount -v'.

Ensure that buffers used for paging indicate the vnode from
which they are operating so that counts of paging I/O operations
from the filesystem are collected.

This checkin only adds the setting of the mount point for the
UFS/FFS filesystem, but it would be trivial to add the setting
and clearing of the mount point at filesystem mount/unmount
time for other filesystems too.

Reviewed by: kib

Do trivial reformatting of the comment to record the missed commit
message for r233609:
Restore the writes of atimes, quotas and superblock from syncer vnode.

Noted by: rdivacky

Reviewed by: bde, mckusick
Tested by: pho
MFC after: 2 weeks

Microoptimize: in qsync loop over mount vnodes, only unlock mount
interlock after we committed to try to vget() the vnode.

Submitted by: bde
Reviewed by: mckusick
Tested by: pho
MFC after: 1 week

Update comment.

MFC after: 3 days

Add a third flags argument to ffs_syncvnode to avoid a possible conflict
with MNT_WAIT flags that passed in its second argument. This will be
MFC'ed together with r232351.

Discussed with: kib

Supply boolean as the second argument to ffs_update(), and not a
MNT_[NO]WAIT constants, which in fact always caused sync operation.

Based on the submission by: bde
Reviewed by: mckusick
MFC after: 2 weeks

Remove superfluous brackets.

Submitted by: alc
MFC after: 2 weeks

Do schedule delayed writes for async mounts.
While there, make some style adjustments, like missed () around
return values.

Submitted by: bde
Reviewed by: mckusick
Tested by: pho
MFC after: 2 weeks

Do not fall back to slow synchronous i/o when low on memory or buffers.
The bawrite() schedules the write to happen immediately, and its use
frees the current thread to do more cleanups.

Submitted by: bde
Reviewed by: mckusick
Tested by: pho
MFC after: 2 weeks

In ffs_syncvnode(), pass boolean false as second argument of ffs_update().
Synchronous inode block update is not needed for MNT_LAZY callers (syncer),
and since waitfor values are not zero, code did unneccessary synchronous
update.

Submitted by: bde
Reviewed by: mckusick
Tested by: pho
MFC after: 2 weeks

Remove not needed ARGSUSED lint command.

Submitted by: bde
MFC after: 3 days

Remove fifo.h. The only used function declaration from the header is
migrated to sys/vnode.h.

Submitted by: gianni

Revert r232692 as the correct place to fix this is at the syscall level.

Decomission mnt_noasync. Introduce MNTK_NOASYNC mnt_kern_flag which
allows a filesystem to request VFS to not allow MNTK_ASYNC.

MFC after: 1 week

Add KTR_VFS traces to track modifications to a vnode's writecount.

syscall() fuzzing can trigger this panic. Return EINVAL instead.

MFC after: 1 week

Similar to the fixes in 226967 and 226987, purge any name cache entries
associated with the previous vnode (if any) associated with the target of
a rename(). Otherwise, a lookup of the target pathname concurrent with a
rename() could re-add a name cache entry after the namei(RENAME) lookup
in kern_renameat() had purged the target pathname.

MFC after: 2 weeks

This change avoids a kernel deadlock on "snaplk" when using
snapshots on UFS filesystems running with journaled soft updates.
This is the first of several bugs that need to be fixed before
removing the restriction added in -r230250 to prevent the use
of snapshots on filesystems running with journaled soft updates.

The deadlock occurs when holding the snapshot lock (snaplk)
and then trying to flush an inode via ffs_update(). We become
blocked by another process trying to flush a different inode
contained in the same inode block that we need. It holds the
inode block for which we are waiting locked. When it tries to
write the inode block, it gets blocked waiting for the our
snaplk when it calls ffs_copyonwrite() to see if the inode
block needs to be copied in our snapshot.

The most obvious place that this deadlock arises is in the
ffs_copyonwrite() routine when it updates critical metadata
in a snapshot and tries to write it out before proceeding.
The fix here is to write the data and indirect block pointer
for the snapshot, but to skip the call to ffs_update() to
write the snapshot inode. To ensure that we will never have
to update a pointer in the inode itself, the ffs_snapshot()
routine that creates the snapshot has to ensure that all the
direct blocks are allocated as part of the creation of the
snapshot.

A less obvious place that this deadlock occurs is when we hold
the snaplk because we are deleting a snapshot. In the course of
doing the deletion, we need to allocate various soft update
dependency structures and allocate some journal space. If we
hit a resource limit while doing this we decrease the resources
in use by flushing out an existing dirty file to get it to give
up the soft dependency resources that it holds. The flush can
cause an ffs_update() to be done on the inode for the file that
we have selected to flush resulting in the same deadlock as
described above when the inode that we have chosen to flush
resides in the same inode block as the snapshot inode that we hold.
The fix is to defer cleaning up any time that the inode on which
we are operating is a snapshot.

Help and review by: Jeff Roberson
Tested by: Peter Holm
MFC (to 9 only) after: 2 weeks

Properly lock DQREF() with dqhlock. Missed locking caused counter
corruption.

Assert that the dq reference value is sane before decrementing it.

Reported and tested by: pho
MFC after: 1 week

Fix found places where uio_resid is truncated to int.

Add the sysctl debug.iosize_max_clamp, enabled by default. Setting the
sysctl to zero allows to perform the SSIZE_MAX-sized i/o requests from
the usermode.

Discussed with: bde, das (previous versions)
MFC after: 1 month

Missing conditions in checking whether an inode has been written.

Found and tested by: Peter Holm
MFC after: 2 weeks (to 9 only)

Historically when an application wrote an entire block of a file,
the kernel allocated a buffer but did not zero it as it was about
to be completely filled by a uiomove() from the user's buffer.
However, if the uiomove() failed, the old contents of the buffer
could be exposed especially if the file was being mmap'ed. The
fix was to always zero the buffer when it was allocated.

This change first attempts the uiomove() to the newly allocated
(and dirty) buffer and only zeros it if the uiomove() fails. The
effect is to eliminate the gratuitous zeroing of the buffer in
the usual case where the uiomove() successfully fills it.

Reviewed by: kib
Tested by: scottl
MFC after: 2 weeks (to 9 only)

In the original days of BSD, a sync was issued on every filesystem
every 30 seconds. This spike in I/O caused the system to pause every
30 seconds which was quite annoying. So, the way that sync worked
was changed so that when a vnode was first dirtied, it was put on
a 30-second cleaning queue (see the syncer_workitem_pending queues
in kern/vfs_subr.c). If the file has not been written or deleted
after 30 seconds, the syncer pushes it out. As the syncer runs once
per second, dirty files are trickled out slowly over the 30-second
period instead of all at once by a call to sync(2).

The one drawback to this is that it does not cover the filesystem
metadata. To handle the metadata, vfs_allocate_syncvnode() is called
to create a "filesystem syncer vnode" at mount time which cycles
around the cleaning queue being sync'ed every 30 seconds. In the
original design, the only things it would sync for UFS were the
filesystem metadata: inode blocks, cylinder group bitmaps, and the
superblock (e.g., by VOP_FSYNC'ing devvp, the device vnode from
which the filesystem is mounted).

Somewhere in its path to integration with FreeBSD the flushing of
the filesystem syncer vnode got changed to sync every vnode associated
with the filesystem. The result of this change is to return to the
old filesystem-wide flush every 30-seconds behavior and makes the
whole 30-second delay per vnode useless.

This change goes back to the originally intended trickle out sync
behavior. Key to ensuring that all the intended semantics are
preserved (e.g., that all inode updates get flushed within a bounded
period of time) is that all inode modifications get pushed to their
corresponding inode blocks so that the metadata flush by the
filesystem syncer vnode gets them to the disk in a timely way.
Thanks to Konstantin Belousov (kib@) for doing the audit and commit
-r231122 which ensures that all of these updates are being made.

Reviewed by: kib
Tested by: scottl
MFC after: 2 weeks

Sprinkle missed calls to asynchronous UFS_UPDATE() in attempt to
guarantee that all UFS inode metadata changes results in the dirtiness
of the inodeblock. Due to missed inodeblock updates, syncer was
required to fsync each mount point' vnode to guarantee periodic
metadata flush.

Reviewed by: mckusick
Tested by: scottl
MFC after: 2 weeks

Add missing opt_quota.h include to activate #ifdef QUOTA blocks,
apparently a step in unbreaking QUOTA support.

Reported and tested by: Adam Strohl <adams-freebsd ateamsystems com>
MFC after: 1 week

JNEWBLK dependency may legitimately appear on the buf dependency
list. If softdep_sync_buf() discovers such dependency, it should do
nothing, which is safe as it is only waiting on the parent buffer to
be written, so it can be removed.

Committed on behalf of: jeff
MFC after: 1 week

Current implementations of sync(2) and syncer vnode fsync() VOP uses
mnt_noasync counter to temporary remove MNTK_ASYNC mount option, which
is needed to guarantee a synchronous completion of the initiated i/o
before syscall or VOP return. Global removal of MNTK_ASYNC option is
harmful because not only i/o started from corresponding thread becomes
synchronous, but all i/o is synchronous on the filesystem which is
initiated during sync(2) or syncer activity.

Instead of removing MNTK_ASYNC from mnt_kern_flag, provide a local
thread flag to disable async i/o for current thread only. Use the
opportunity to move DOINGASYNC() macro into sys/vnode.h and
consistently use it through places which tested for MNTK_ASYNC.

Some testing demonstrated 60-70% improvements in run time for the
metadata-intensive operations on async-mounted UFS volumes, but still
with great deviation due to other reasons.

Reviewed by: mckusick
Tested by: scottl
MFC after: 2 weeks

There are several bugs/hangs when trying to take a snapshot on a UFS/FFS
filesystem running with journaled soft updates. Until these problems
have been tracked down, return ENOTSUPP when an attempt is made to
take a snapshot on a filesystem running with journaled soft updates.

MFC after: 2 weeks

Make sure all intermediate variables holding mount flags (mnt_flag)
and that all internal kernel calls passing mount flags are declared
as uint64_t so that flags in the top 32-bits are not lost.

MFC after: 2 weeks

Add a bit of verbosity to the comment.

Convert FFS mount error messages from kernel printf's to using the
vfs_mount_error error message facility provided by the nmount
interface.

Clean up formatting of mount warnings which still need to use
kernel printf's since they do not return errors.

Requested by: Craig Rodrigues <rodrigc@crodrigues.org>
MFC after: 2 weeks

Avoid LOR between vfs_busy() lock and covered vnode lock on quotaon().
The vfs_busy() is after covered vnode lock in the global lock order, but
since quotaon() does recursive VFS call to open quota file, we usually
end up locking covered vnode after mp is busied in sys_quotactl().

Change the interface of VFS_QUOTACTL(), requiring that mp was unbusied
by fs code, and do not try to pick up vfs_busy() reference in ufs quotaon,
esp. if vfs_busy cannot succeed due to unmount being performed.

Reported and tested by: pho
MFC after: 1 week

Migrate ufs and ext2fs from skpc() to memcchr().

While there, remove a useless check from the code. memcchr() always
returns characters unequal to 0xff in this case, so inosused[i] ^ 0xff
can never be equal to zero. Also, the fact that memcchr() returns a
pointer instead of the number of bytes until the end, makes conversion
to an offset far more easy.

Use implementation independent inoNN_t scalars for on-disk UFS structures

Approved by: mdf (mentor)

Mark all SYSCTL_NODEs static that have no corresponding SYSCTL_DECLs.

The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.

Remove MALLOC_DECLAREs of nonexisting malloc-pools.

After careful grepping, it seems none of these pools can be found in our
source tree. They are not in use, nor are they defined.

Fix the wrong commit log message for r226967: "Added missing cache purge
of from argument" and fix the comment.

The kern_renameat() looks up the fvp using the DELETE flag, which causes
the removal of the name cache entry for fvp.

Reported by: Anton Yuzhaninov <citrin citrin ru>
In collaboration with: kib
MFC after: 1 week

This update eliminates a lock-order reversal warning discovered
whle tracking down the system hang reported in kern/160662 and
corrected in revision 225806. The LOR is not the cause of the system
hang and indeed cannot cause an actual deadlock. However, it can
be easily eliminated by defering the acquisition of a buflock until
after all the vnode locks have been acquired.

Reported by: Hans Ottevanger
PR: kern/160662

This update eliminates the system hang reported in kern/160662 when
taking a snapshot on a filesystem running with journaled soft updates.

Reported by: Hans Ottevanger
Fix verified by: Hans Ottevanger
PR: kern/160662

Use nowait sync request for a vnode when doing softdep cleanup. We possibly
own the unrelated vnode lock, doing waiting sync causes deadlocks.

Reported and tested by: pho
Approved by: re (bz)

Generalize ffs_pages_remove() into vn_pages_remove().

Remove mapped pages for all dataset vnodes in zfs_rezget() using
new vn_pages_remove() to fix mmapped files changed by
zfs rollback or zfs receive -F.

PR: kern/160035, kern/156933
Reviewed by: kib, pjd
Approved by: re (kib)
MFC after: 1 week

Fix lock leak.

Reported by: Alex Lyashkov
Approved by: re (kib)
MFC after: 1 week

Fix two cases involving opt_capsicum.h and module builds:

(1) opt_capsicum.h is no longer required in ffs_alloc.c, so remove the
#include.

(2) portalfs depends on opt_capsicum.h, so have the Makefile generate one
if required.

These affect only modules built without a kernel (i.e, not buildkernel,
but yes buildworld if the dubious MODULES_WITH_WORLD is used).

Approved by: re (bz)
Sponsored by: Google Inc

Second-to-last commit implementing Capsicum capabilities in the FreeBSD
kernel for FreeBSD 9.0:

Add a new capability mask argument to fget(9) and friends, allowing system
call code to declare what capabilities are required when an integer file
descriptor is converted into an in-kernel struct file *. With options
CAPABILITIES compiled into the kernel, this enforces capability
protection; without, this change is effectively a no-op.

Some cases require special handling, such as mmap(2), which must preserve
information about the maximum rights at the time of mapping in the memory
map so that they can later be enforced in mprotect(2) -- this is done by
narrowing the rights in the existing max_protection field used for similar
purposes with file permissions.

In namei(9), we assert that the code is not reached from within capability
mode, as we're not yet ready to enforce namespace capabilities there.
This will follow in a later commit.

Update two capability names: CAP_EVENT and CAP_KEVENT become
CAP_POST_KEVENT and CAP_POLL_KEVENT to more accurately indicate what they
represent.

Approved by: re (bz)
Submitted by: jonathan
Sponsored by: Google Inc

Update to -r224294 to ensure that only one of MNT_SUJ or MNT_SOFTDEP
is set so that mount can revert back to using MNT_NOWAIT when doing
getmntinfo.

Approved by: re (kib)

Move the MNTK_SUJ flag in mnt_kern_flag to MNT_SUJ in mnt_flag
so that it is visible to userland programs. This change enables
the `mount' command with no arguments to be able to show if a
filesystem is mounted using journaled soft updates as opposed
to just normal soft updates.

Approved by: re (bz)

Default debugging error messages to off for journaled soft updates sysctls.
Delete limiting on output of these sysctls.

Approved by: re (kib)

Add an FFS specific mount option to allow a filesystem checker
(typically fsck_ffs) to register that it wishes to use FFS specific
sysctl's to update the filesystem. This ensures that two checkers
cannot run on a given filesystem at the same time and that no other
process accidentally or maliciously uses the filesystem updating
sysctls inappropriately. This functionality is needed by the
journaling soft-updates recovery code.

Consistently check mount flag (MNTK_SUJ) rather than superblock
flag (FS_SUJ) when determining whether to do journaling-based
operations. The mount flag is set only when journaling is active
while the superblock flag is set to indicate that journaling is to
be used. For example, when the filesystem is mounted read-only, the
journaling may be present (FS_SUJ) but not active (MNTK_SUJ).
Inappropriate checking of the FS_SUJ flag was causing some
journaling actions to be attempted at inappropriate times.

When first creating snapshots, we may free some blocks within it.
These blocks should not have TRIM applied to them.

Submitted by: Kostik Belousov

Allow disk partitions associated with UFS read-only mounted
filesystems to be opened for writing. This functionality used to
be special-cased for just the root filesystem, but with this change
is now available for all UFS filesystems. This change is needed for
journaled soft updates recovery.

Discussed with: Jeff Roberson

Use 'curthread_pflags' instead of 'thread_pflags' to signify that only
curthread can be operated upon.

Requested by: attilio
MFC after: 1 week

Use helper functions instead of manually managing TDP_INBDFLUSH.

Sponsored by: The FreeBSD Foundation
Reviewed by: alc (previous version)
MFC after: 1 week

- Speed up pendingblock processing again. Having too much delay between
ffs_blkfree() and the pending adjustment causes all kinds of
space related problems.

- Handle D_JSEGDEP in the softdep_sync_buf() switch. These can now
find themselves on snapshot vnodes.

Reported by: pho

- It is impossible to run request_cleanup() while doing a copyonwrite.
This will most likely cause new block allocations which can recurse
into request cleanup.
- While here optimize the ufs locking slightly. We need only acquire and
drop once.
- process_removes() and process_truncates() also is only needed once.
- Attempt to flush each item on the worklist once but do not loop forever
if some can not be completed.

Discussed with: mckusick

- Fix an inode quota leak. We need to decrement the quota once and only
once.

Tested by: pho
Reviewed by: mckusick

Handle the FREEDEP case in softdep_sync_buf().
This fix failed to get added in -r223325.

Submitted by: Peter Holm

Add a new option, OBJPR_NOTMAPPED, to vm_object_page_remove(). Passing this
option to vm_object_page_remove() asserts that the specified range of pages
is not mapped, or more precisely that none of these pages have any managed
mappings. Thus, vm_object_page_remove() need not call pmap_remove_all() on
the pages.

This change not only saves time by eliminating pointless calls to
pmap_remove_all(), but it also eliminates an inconsistency in the use of
pmap_remove_all() versus related functions, like pmap_remove_write(). It
eliminates harmless but pointless calls to pmap_remove_all() that were being
performed on PG_UNMANAGED pages.

Update all of the existing assertions on pmap_remove_all() to reflect this
change.

Reviewed by: kib

- Fix directory count rollbacks by passing the mode to the journal dep
earlier.
- Add rollback/forward code for frag and cluster accounting.
- Handle the FREEDEP case in softdep_sync_buf(). (submitted by pho)

Fixed dereference of a NULL pointer.

Reported by: Peter Holm

Drop the include of <ufs/ffs/ffs_extern.h> from usr.sbin/makefs/ffs/ffs_bswap.c
and usr.sbin/makefs/ffs/ffs_subr.c as they have no need of anything in that
file. No other programs or libraries include <ufs/ffs/ffs_extern.h> (nor
should they as it is totally in-kernel interfaces). For added protection
I enclosed the entire contents of <ufs/ffs/ffs_extern.h> in ifdef _KERNEL.

Feedback from: Bruce Evans and Tai-hwa Liang

Fixing compilation bustage by introducing another forward declaration.

Ensure that filesystem metadata contained within persistent snapshots
is always kept consistent.

Suggested by: Jeff Roberson

With the restructuring of the block reclaimation code, the notification
messages for a filesystem being out of space need to be moved so that
they do not print out until after a failed cleanup attempt.

Suggested by: Jeff Roberson

Missing cleanup case after completion of a snapshot vnode write
claiming a released block.

Submitted by: Jeff Roberson
Tested by: Peter Holm

Use alternative, less messy solution to avoid breakage after r223020:
put the snapdata structure between #ifdef _KERNEL guards.

Suggested by: kib

Update to soft updates journaling to properly track freed blocks
that get claimed by snapshots.

Submitted by: Jeff Roberson
Tested by: Peter Holm

Disable the soft updates journaling after a filesystem is successfully
downgraded to read-only. It will be restarted if the filesystem is
upgraded back to read-write.

Implement fully asynchronous partial truncation with softupdates journaling
to resolve errors which can cause corruption on recovery with the old
synchronous mechanism.

- Append partial truncation freework structures to indirdeps while
truncation is proceeding. These prevent new block pointers from
becoming valid until truncation completes and serialize truncations.
- On completion of a partial truncate journal work waits for zeroed
pointers to hit indirects.
- softdep_journal_freeblocks() handles last frag allocation and last
block zeroing.
- vtruncbuf/ffs_page_remove moved into softdep_*_freeblocks() so it
is only implemented in one place.
- Block allocation failure handling moved up one level so it does not
proceed with buf locks held. This permits us to do more extensive
reclaims when filesystem space is exhausted.
- softdep_sync_metadata() is broken into two parts, the first executes
once at the start of ffs_syncvnode() and flushes truncations and
inode dependencies. The second is called on each locked buf. This
eliminates excessive looping and rollbacks.
- Improve the mechanism in process_worklist_item() that handles
acquiring vnode locks for handle_workitem_remove() so that it works
more generally and does not loop excessively over the same worklist
items on each call.
- Don't corrupt directories by zeroing the tail in fsck. This is only
done for regular files.
- Push a fsync complete record for files that need it so the checker
knows a truncation in the journal is no longer valid.

Discussed with: mckusick, kib (ffs_pages_remove and ffs_truncate parts)
Tested by: pho

- Add support for referencing quota structures without needing the inode
pointer for softupdates.

Submitted by: mckusick

- If the fsync in ufs_direnter fails SUJ can later panic because we have
partially added a name. Allow ufs_direnter() to continue in the
hopes that it is a transient error. If it is not, the directory
is corrupted already from IO errors and writing this new block
is not likely to make things worse.

Grammer fix in comment.

Eliminate one (of several) possible conflicting buffer locks when
trying to reclaim blocks. Rest of fix to be incorporated as part
of SUJ update by jeff.

Pointed out by: Kostik Belousov

Due to a lag in updating the fs_pendinginodes count, we cannot depend
on it to decide whether we should try to reclaim inodes when we run
short.

Discovered by: Peter Holm

The check for whether a block is going to be claimed by a snapshot
needs to happen before we notify the underlying layer that it is
being freed.

Fix the ufs/ffs file system so that it uses the lock
flags argument added to VFS_FHTOVP() by r222167.

Reviewed by: mckusick

Add a lock flags argument to the VFS_FHTOVP() file system
method, so that callers can indicate the minimum vnode
locking requirement. This will allow some file systems to choose
to return a LK_SHARED locked vnode when LK_SHARED is specified
for the flags argument. This patch only adds the flag. It
does not change any file system to use it and all callers
specify LK_EXCLUSIVE, so file system semantics are not changed.

Reviewed by: kib

Use a name instead of a magic number for kern_yield(9) when the priority
should not change. Fetch the td_user_pri under the thread lock. This
is probably not necessary but a magic number also seems preferable to
knowing the implementation details here.

Requested by: Jason Behmer < jason DOT behmer AT isilon DOT com >

Fix typos.

Noted by: Fabian Keil <freebsd-listen fabiankeil de>
Pointy hat to: kib
MFC after: 1 week

Clarify the comment.

MFC after: 1 week

VFS sometimes is unable to inactivate a vnode when vnode use count
goes to zero. E.g., the vnode might be only shared-locked at the time of
vput() call. Such vnodes are kept in the hash, so they can be found later.

If ffs_valloc() allocated an inode that has its vnode cached in hash, and
still owing the inactivation, then vget() call from ffs_valloc() clears
VI_OWEINACT, and then the vnode is reused for the newly allocated inode.

The problem is, the vnode is not reclaimed before it is put to the new
use. ffs_valloc() recycles vnode vm object, but this is not enough.
In particular, at least v_vflag should be cleared, and several bits of
UFS state need to be removed.

It is very inconvenient to call vgone() at this point. Instead, move
some parts of ufs_reclaim() into helper function ufs_prepare_reclaim(),
and call the helper from VOP_RECLAIM and ffs_valloc().

Reviewed by: mckusick
Tested by: pho
MFC after: 3 weeks

- Refactor softdep_setup_freeblocks() into a set of functions to prepare
for a new journal specific partial truncate routine.
- Use dep_current[] in place of specific dependency counts. This is
automatically maintained when workitems are allocated and has
less risk of becoming incorrect.

Fix a long standing SUJ performance problem:

- Keep a hash of indirect blocks that have recently been freed and are
still referenced in the journal.
- Lookup blocks in this hash before forcing a new block write to wait on
the journal entry to hit the disk. This is only necessary to avoid
confusion between old identities as indirects and new identities as
file blocks.
- Don't free jseg structures until the journal has written a record that
invalidates it. This keeps the indirect block information around for
as long as is required to be safe.
- Force an empty journal block write when required to flush out stale
journal data that is simply waiting for the oldest valid sequence
number to advance beyond it.

- Don't invalidate jnewblks immediately upon discovering that the block
will be removed. Permit the journal to proceed so that we don't leave
a rollback in a cg for a very long time as this can cause terrible perf
problems in low memory situations.

Tested by: pho

Be far more persistent in reclaiming blocks and inodes before giving
up and declaring a filesystem out of space. Especially necessary when
running on a small filesystem. With this improvement, it should be
possible to use soft updates on a small root filesystem.

Kudos to: Peter Holm
Testing by: Peter Holm
MFC: 2 weeks

Fix problems that manifested from filesystem full conditions:

- In softdep_revert_mkdir() find the dotaddref before we attempt to cancel
the jaddref so we can make assumptions about where the dotaddref is on
the list. cancel_jaddref() does not always remove items from the list
anymore.
- Always set GOINGAWAY on an inode in softdep_freefile() if DEPCOMPLETE
was never set. This ensures that dependencies will continue to be
processed on the inowait/bufwait list and is more an artifact of
the structure of the code than a pure ordering problem.
- Always set DEPCOMPLETE on canceled jaddrefs so that they can be freed
appropriately. This normally occurs when the refs are added to the
journal but if they are canceled before this point the state would
never be set and the dependency could never be freed.

Reported by: pho
Tested by: pho

Fix the softdep_request_cleanup() function definition for !SOFTUPDATES case.

Submitted by: Aleksandr Rybalko <ray dlink ua>

Add retry code analogous to the block allocation retry code
to avoid running out of inodes.

Reported by: Peter Holm

Retire opt_ffs_broken_fixme.h.
Instead of directly calling ffs_snapgone(), use UFS_SNAPGONE() with
usual layering.

Requested by: bde
MFC after: 1 week

Remove the #if defined(FFS) || defined(IFS) braces around the calls to
ffs_snapgone(). ufs.ko module is not build with FFS define, causing
snapshot inode number slots in superblock never be freed, as well as a
reference on the snapshot vnode.

IFS was removed several years ago, and UFS/FFS separation was not
maintained for real.

Reported, analyzed and tested by: Yamagi Burmeister <lists yamagi org>
MFC after: 3 days

Simplify uses of the web of pointers.

Reviewed by: mckusick
MFC after: 1 week

The UFS dirhash code was attempting to update shared state in the dirhash
from multiple threads while holding a shared lock during a lookup operation.
This could result in incorrect ENOENT failures which could then be
permanently stored in the name cache.

Specifically, the dirhash code optimizes the case that a single thread is
walking a directory sequentially opening (or stat'ing) each file. It uses
state in the dirhash structure to determine if a given lookup is using the
optimization. If the optimization fails, it disables it and restarts the
lookup. The problem arises when two threads both attempt the optimization
and fail. The first thread will restart the loop, but the second thread
will incorrectly think that it did not try the optimization and will only
examine a subset of the directory entires in its hash chain. As a result,
it may fail to find its directory entry and incorrectly fail with ENOENT.

To make this safe for use with shared locks, simplify the state stored in
the dirhash and move some of the state (the part that determines if the
current thread is trying the optimization) into a local variable. One
result is that we will now try the optimization more often. We still
update the value under the shared lock, but it is a single atomic store
similar to i_diroff that is stored in UFS directory i-nodes for the
non-dirhash lookup.

Reviewed by: kib
MFC after: 1 week

Use ffs() to locate free bits in the inode bitmap rather than a loop with
bit shifts.

Reviewed by: mckusick
MFC after: 1 month

v_mountedhere is a member of the union. Check that the vnodes have
proper type before using the member.

Reported and tested by: Michael Butler <imb protected-networks net>

Use the native sector size of the device backing the UFS volume for SU+J
journal blocks, instead of hard coding 512 byte sector size. Journal need
to atomically write the block, that can only be guaranteed at the device
sector size, not larger. Attempt to write less then sector size results in
driver errors.

Note that this is the first structure in UFS that depends on the
sector size. Other elements are written in the units of fragments.

In collaboration with: pho
Reviewed by: jeff
Tested by: bz, pho

Wrap long line.

Noticed by: bz

Add some FEATURE macros for some UFS features.

SU+J is not included as a FEATURE macro:
- it was not in the tree during the GSoC
- I do not see an option to en-/disable it in NOTES

Two minor changes where made during the review compared to what was developed
during GSoC 2010.

No FreeBSD version bump, the userland application to query the features will
be committed last and can serve as an indication of the availablility if
needed.

Sponsored by: Google Summer of Code 2010
Submitted by: kibab
Reviewed by: kib
X-MFC after: to be determined in last commit with code from this project

Based on discussions on the svn-src mailing list, rework r218195:

- entirely eliminate some calls to uio_yeild() as being unnecessary,
such as in a sysctl handler.

- move should_yield() and maybe_yield() to kern_synch.c and move the
prototypes from sys/uio.h to sys/proc.h

- add a slightly more generic kern_yield() that can replace the
functionality of uio_yield().

- replace source uses of uio_yield() with the functional equivalent,
or in some cases do not change the thread priority when switching.

- fix a logic inversion bug in vlrureclaim(), pointed out by bde@.

- instead of using the per-cpu last switched ticks, use a per thread
variable for should_yield(). With PREEMPTION, the only reasonable
use of this is to determine if a lock has been held a long time and
relinquish it. Without PREEMPTION, this is essentially the same as
the per-cpu variable.

Put the general logic for being a CPU hog into a new function
should_yield(). Use this in various places. Encapsulate the common
case of check-and-yield into a new function maybe_yield().

Change several checks for a magic number of iterations to use
should_yield() instead.

MFC after: 1 week

Embed a quota error message (C string) into uprintf() fmt.
While here, fix whitespaces.

Approved by: kib (mentor)

sysctl(9) cleanup checkpoint: amd64 GENERIC builds cleanly.

Commit the kernel changes.

Instead of incrementing freework reference counter in indir_trunc(), do
it at the allocation time for journaled fs and indirect blocks, when
the allocated object is not accessible outside.

Requested and reviewed by: jeff
Tested by: pho

Handle missing jremrefs when a directory is renamed overtop of
another, deleting it. If the directory is removed, UFS always need to
remove the .. ref, even if the ultimate ref on the parent would not
change. The new directory must have a new journal entry for that ref.
Otherwise journal processing would not properly account for the
parent's reference since it will belong to a removed directory entry.

Change ufs_rename()'s dotdot rename section to always
setup_dotdot_link(). In the tip != NULL case SUJ needs the newref dependency
allocated via setup_dotdot_link().

Stop setting isrmdir to 2 for newdirrem() in softdep_setup_remove().
Remove the isdirrem > 1 checks from newdirrem().

Reported by: many
Submitted by: jeff
Tested by: pho

In indir_trunc(), when processing jnewblk entries that are not written
to the disk, recurse to handle indirect blocks of next level that are
hidden by the corresponding entry.

In collaboration with: pho
Reviewed by: jeff, mckusick
Tested by: mckusick, pho

Add kernel side support for BIO_DELETE/TRIM on UFS.

The FS_TRIM fs flag indicates that administrator requested issuing of
TRIM commands for the volume. UFS will only send the command to disk
if the disk reports GEOM::candelete attribute.

Since disk queue is reordered, data block is marked as free in the bitmap
only after TRIM command completed. Due to need to sleep waiting for
i/o to finish, TRIM bio_done routine schedules taskqueue to set the
bitmap bit.

Based on the patch by: mckusick
Reviewed by: mckusick, pjd
Tested by: pho
MFC after: 1 month

Move the definition of mkdirlisthd from header to C file.

Reviewed by: mckusick
Tested by: pho

Use a proper type for the variable holding the summary size of the inode
data. Otherwise, on 32bit systems, unlinked inode which size is the
multiple of 4GB was not truncated, causing corruption.

Reported by: brucec
Reviewed by: mckusick
Tested by: pho

This patch fixes a soft update panic while running perl 5.12 tests
which produced:

panic: indir_trunc: Index out of range -148 parent -2061 lbn -305164

Reported by: Dimitry Andric
Fixed by: Jeff Roberson

Journal start looks up .sujournal file by doing lookup on the root dvp.
As result, failed softdep_mount() might leave up to two vnodes on the
mp mountlist, preventing mnt_ref from going to zero.

Call ffs_flushfiles() after failed softdep_mount() to clean mountlist.

Initial report by: Garrett Cooper
Reproduced and tested by: pho

First step in fixing the handle_workitem_freeblocks panic.

In collaboration with: kib

Delete /sys/ufs/ffs/README.snapshot as it is no longer relevant.
Drop reference to it in mount(8).

MFC: 3 days

Remove prtactive variable and related printf()s in the vop_inactive
and vop_reclaim() methods. They seems to be unused, and the reported
situation is normal for the forced unmount.

MFC after: 1 week
X-MFC-note: keep prtactive symbol in vfs_subr.c

The softdep_setup_freeblocks() adds worklist items before
deallocate_dependencies() is done. This opens a race between softdep
thread and the thread that does the truncation:
A write of the indirect block causes the freeblks to become
ALLCOMPLETE while softdep_setup_freeblocks() dropped softdep lock. And
then, softdep_disk_write_complete() would reassign the workitem to the
mount point worklist, causing premature processing of the workitem, or
journal write exhaust the fb_jfreeblkhd and handle_written_jfreeblk does
the same reassign.
indir_trunc() then would find the indirect block that is locked (with lock
owned by kernel) but without any dependencies, causing it to hang in
getblk() waiting for buffer lock.

Do not mark freeblks as DEPCOMPLETE until deallocate_dependencies()
finished.

Analyzed, suggested and reviewed by: jeff
Tested by: pho

Change #ifdef INVARIANTS panic into KASSERT, and print some useful
information to diagnose the issue, in handle_complete_freeblocks().

Reviewed by: jeff
Tested by: pho

In journal_mount(), only set MNTK_SUJ flag after the jblocks are mapped.
I believe there is a window otherwise where jblocks can be accessed
without proper initialization.

Reviewed by: jeff
Tested by: pho

Add function lbn_offset to calculate offset of the indirect block of
given level.

Reviewed by: jeff
Tested by: pho

Fix typo. Function is called ffs_blkfree.

Remove unused includes of <sys/mutex.h> and <machine/mutex.h>.

Bring vfs.ufs.dirhash_maxmem into the age of the fruitbat and make it
autotuned. It is only an upper bound (the memory is not always allocated)
and the system contains a vm_lowmem handler so nothing will crash and burn
if it's tuned too high.

Reviewed by: mckusick

The r184588 changed the layout of struct export_args, causing an ABI
breakage for old mount(2) syscall, since most struct <filesystem>_args
embed export_args. The mount(2) is supposed to provide ABI
compatibility for pre-nmount mount(8) binaries, so restore ABI to
pre-r184588.

Requested and reviewed by: bde
MFC after: 2 weeks

M_USE_RESERVE has been deprecated for a decade. Eliminate any uses that
have no run-time effect.

Since local variable 'i' is used only in a KASSERT, declare and
initialize it only if INVARIANTS is defined to avoid a declared
but unused warning.

Suggested by: Brian Somers <brian@FreeBSD.org>

Fix typo in comment.

Correct some non-code typos.

Update comments in soft updates code to more fully describe
the addition of journalling. Only functional change is to
tighten a KASSERT.

Reviewed by: jeff Roberson

Add dedicated routines to toggle lockmgr flags such as LK_NOSHARE and
LK_CANRECURSE after a lock is created. Use them to implement macros that
otherwise manipulated the flags directly. Assert that the associated
lockmgr lock is exclusively locked by the current thread when manipulating
these flags to ensure the flag updates are safe. This last change required
some minor shuffling in a few filesystems to exclusively lock a brand new
vnode slightly earlier.

Reviewed by: kib
MFC after: 3 days

Softdep_process_worklist() should unsuspend not only before processing
the worklist (in softdep_process_journal), but also after flushing the
workitems. Might be, we should even do this before bwillwrite() too, but
this seems to be not needed for now.

Fs might be suspended during processing the queue, and then there is
nobody around to unsuspend.

In collaboration with: pho
Tested by: bz
Reviewed by: jeff

Revert the previous commit. The race is not applicable to the lockmgr
implementation in 8.0 and later as its flags field does not hold dynamic
state such as waiters flags, but is only modified in lockinit() aside
from VN_LOCK_*().

Discussed with: attilio

When the MNTK_EXTENDED_SHARED mount option was added, some filesystems were
changed to defer the setting of VN_LOCK_ASHARE() (which clears LK_NOSHARE
in the vnode lock's flags) until after they had determined if the vnode was
a FIFO. This occurs after the vnode has been inserted a VFS hash or some
similar table, so it is possible for another thread to find this vnode via
vget() on an i-node number and block on the vnode lock. If the lockmgr
interlock (vnode interlock for vnode locks) is not held when clearing the
LK_NOSHARE flag, then the lk_flags field can be clobbered. As a result
the thread blocked on the vnode lock may never get woken up. Fix this by
holding the vnode interlock while modifying the lock flags in this case.

MFC after: 3 days

- Handle the truncation of an inode with an effective link count of 0 in
the context of the process that reduced the effective count. Previously
all truncation as a result of unlink happened in the softdep flush
thread. This had the effect of being impossible to rate limit properly
with the journal code. Now the process issuing unlinks is suspended
when the journal files. This has a side-effect of improving rm
performance by allowing more concurrent work.
- Handle two cases in inactive, one for effnlink == 0 and another when
nlink finally reaches 0.
- Eliminate the SPACECOUNTED related code since the truncation is no
longer delayed.

Discussed with: mckusick

Ensure that VOP_ACCESSX is called with exclusively locked vnode for
the kernel compiled with QUOTA option. ufs_accessx() upgrades the vdp
vnode lock from shared to exclusive to assign the dquot structure to
the vnode, and ufs_delete_denied() is called when tvp is locked. Since
upgrade drops shared lock when non-blocked upgrade failed, LOR is there.

Reported and tested by: Dmitry Pryanishnikov <lynx.ripe gmail com>
Tested by: pho
PR: kern/147890
MFC after: 1 week

ffs_softdep: change K&R in function defintions to ANSI prototypes

Apparently it's bad when we first have an ANSI prototype in function
declaration, but then use K&R in its defintion.

Complaint from: clang
MFC after: 2 weeks

Extend the scope of the lock on the quota file vnode in quotaon() to
cover the initial read by dqopen(). Assert that vnode is locked in
dqopen(). Remove VFS_LOCK_GIANT() from dqopen(), since quotaon() keeps
Giant locked if needed around the call.

ffs_mount: accept and drop userland-only options that can be passed from
loader(8)

In r193192 loader(8) has grown an ability to pass root mount options
from fstab via vfs.root.mountfrom.options. Unfortunately, some options
that can be present in fstab are for userland only and lead to root
mounting failure when seen by kernel.
Rather than teaching loader about FFS-specific options that should be
filtered out, ffs_mount recognizes those options as valid, but ignores
and deletes[1] them.

[1] is suggested by jh.

PR: kern/141050
Reported by: many
Reviewed by: jh, bde
MFC after: 4 days

- Don't immediately re-run softdepflush if we didn't make any progress
on the last iteration. This can lead to a deadlock when we have
worklist items that cannot be immediately satisfied.

Reported by: uqs, Dimitry Andric <dimitry@andric.com>

- Remove some unnecessary debugging code and place some other under
SUJ_DEBUG.
- Examine the journal state in softdep_slowdown().
- Re-format some comments so I may more easily add flag descriptions.

- Call softdep_prealloc() before any of the balloc routines in the
snapshot code.
- Don't fsync() vnodes in prealloc if copy on write is in progress. It
is not safe to recurse back into the write path here.

Reported by: Vladimir Grebenschikov <vova@fbsd.ru>

- Use the correct flag mask when determining whether an inode has
successfully made it to the free list yet or not. This fixes
a deadlock that can occur with unlinked but referenced files.
Journal space and inodedeps were not correctly reclaimed because
the inode block was not left dirty.

Tested/Reported by: lwindschuh@googlemail.com

Merger of the quota64 project into head.

This joint work of Dag-Erling Smørgrav and myself updates the
FFS quota system to support both traditional 32-bit and new 64-bit
quotas (for those of you who want to put 2+Tb quotas on your users).

By default quotas are not compiled into the kernel. To include them
in your kernel configuration you need to specify:

options QUOTA # Enable FFS quotas

If you are already running with the current 32-bit quotas, they
should continue to work just as they have in the past. If you
wish to convert to using 64-bit quotas, use `quotacheck -c 64';
if you wish to revert from 64-bit quotas back to 32-bit quotas,
use `quotacheck -c 32'.

There is a new library of functions to simplify the use of the
quota system, do `man quotafile' for details. If your application
is currently using the quotactl(2), it is highly recommended that
you convert your application to use the quotafile interface.
Note that existing binaries will continue to work.

Special thanks to John Kozubik of rsync.net for getting me
interested in pursuing 64-bit quota support and for funding
part of my development time on this project.

Eliminate page queues locking around most calls to vm_page_free().

Acquire the page lock around all remaining calls to vm_page_free() on
managed pages that didn't already have that lock held. (Freeing an
unmanaged page, such as the various pmaps use, doesn't require the page
lock.)

This allows a change in vm_page_remove()'s locking requirements. It now
expects the page lock to be held instead of the page queues lock.
Consequently, the page queues lock is no longer required at all by callers
to vm_page_rename().

Discussed with: kib

Move checking against RLIMIT_FSIZE into one place, vn_rlimit_fsize().

Reviewed by: kib

ffs_vfsops: restore alphabetic order of options in ffs_opts

The order was not correct only for nfsv4acls.
("no" prefix is ignored)

MFC after: 1 week

- When canceling jaddrefs they may not yet be in the journal if this is via
a revert call. In this case don't attempt to remove something that
has not yet been added. Otherwise this jaddref must hang around
to prevent the bitmap write as normal.

- Fix builds without SOFTUPDATES defined in the kernel config.

Fix build for UFS without SOFTUPDATES.

- Merge soft-updates journaling from projects/suj/head into head. This
brings in support for an optional intent log which eliminates the need
for background fsck on unclean shutdown.

Sponsored by: iXsystems, Yahoo!, and Juniper.
With help from: McKusick and Peter Holm

The cache_enter(9) function shall not be called for doomed dvp.
Assert this.

In the reported panic, vdestroy() fired the assertion "vp has namecache
for ..", because pseudofs may end up doing cache_enter() with reclaimed
dvp, after dotdot lookup temporary unlocked dvp.
Similar problem exists in ufs_lookup() for "." lookup, when vnode
lock needs to be upgraded.

Verify that dvp is not reclaimed before calling cache_enter().

Reported and tested by: pho
Reviewed by: kan
MFC after: 2 weeks

ffs_mount: remove redundant assignment of geom consumer to devvp.v_bufobj

The assignment is already done in g_vfs_open.
Redundant assignment is harmless, but can become a problem if g_vfs_open
logic is changed.

MFC after: 1 week

When ffs_realloccg() failed to allocate bigger fragment and, because
pending blocks are scheduled for removal, goes to retry the (re)allocation,
clear the bp pointer. It might happen that meantime free space is really
exhausted and we are entering nospace: label without bread()ing buffer,
causing stale bp value to be brelse()d again.

Tested by: pho
(Producing a scenario to reliably reproduce the
race appeared to be much harder then fixing the bug)
MFC after: 1 week

One last pass to get all the unsigned comparisons correct.

This fix corrects a problem in the file system that treats large
inode numbers as negative rather than unsigned. For a default
(16K block) file system, this bug began to show up at a file system
size above about 16Tb.

To fully handle this problem, newfs must be updated to ensure that
it will never create a filesystem with more than 2^32 inodes. That
patch will be forthcoming soon.

Reported by: Scott Burns, John Kilburg, Bruce Evans
Followup by: Jeff Roberson
PR: 133980
MFC after: 2 weeks

Remove unused variable.

Return proper error code.

Found with: clang

Move out code that does POSIX.1e ACL inheritance into separate routines.

Reviewed by: rwatson

Cast 64-bit quantity to intptr_t rather than int so as to work properly
with 64-bit architectures (such as amd64).

Reported by: bz

Background:

When renaming a directory it passes through several intermediate
states. First its new name will be created causing it to have two
names (from possibly different parents). Next, if it has different
parents, its value of ".." will be changed from pointing to the old
parent to pointing to the new parent. Concurrently, its old name
will be removed bringing it back into a consistent state. When fsck
encounters an extra name for a directory, it offers to remove the
"extraneous hard link"; when it finds that the names have been
changed but the update to ".." has not happened, it offers to rewrite
".." to point at the correct parent. Both of these changes were
considered unexpected so would cause fsck in preen mode or fsck in
background mode to fail with the need to run fsck manually to fix
these problems. Fsck running in preen mode or background mode now
corrects these expected inconsistencies that arise during directory
rename. The functionality added with this update is used by fsck
running in background mode to make these fixes.

Solution:

This update adds three new fsck sysctl commands to support background
fsck in correcting expected inconsistencies that arise from incomplete
directory rename operations. They are:

setcwd(dirinode) - set the current directory to dirinode in the
filesystem associated with the snapshot.
setdotdot(oldvalue, newvalue) - Verify that the inode number for ".."
in the current directory is oldvalue then change it to newvalue.
unlink(nameptr, oldvalue) - Verify that the inode number associated
with nameptr in the current directory is oldvalue then unlink it.

As with all other fsck sysctls, these new ones may only be used by
processes with appropriate priviledge.

Reported by: jeff
Security issues: rwatson

Remove extraneous semicolons, no functional changes.

Submitted by: Marc Balmer <marc@msys.ch>
MFC after: 1 week

KASSERT that condition raised by Coverity cannot happen.

Found by: Coverity Prevent (tm)
KASSERT by: sam

Implement NFSv4 ACL support for UFS.

Reviewed by: rwatson

VI_OBJDIRTY vnode flag mirrors the state of OBJ_MIGHTBEDIRTY vm object
flag. Besides providing the redundand information, need to update both
vnode and object flags causes more acquisition of vnode interlock.
OBJ_MIGHTBEDIRTY is only checked for vnode-backed vm objects.

Remove VI_OBJDIRTY and make sure that OBJ_MIGHTBEDIRTY is set only for
vnode-backed vm objects.

Suggested and reviewed by: alc
Tested by: pho
MFC after: 3 weeks

Don't build ufs_gjournal.c at all if UFS_GJOURNAL option is not given
instead of building an almost empty C file.

Approved by: pjd
Approved by: ed (mentor, implicit)

Allocate space for the group array in a static credential used in
the quota code. One case was correctly handled in r194498, but
this one was missed.

PR: kern/138657
Tested by: PR submitter
MFC after: 3 days

Remove useless variable assignment.

insmntque_stddtr() clears vp->v_data and resets vp->v_op to
dead_vnodeops before calling vgone(). Revert r189706 and corresponding
part of the r186560.

Noted and reviewed by: tegge
Approved by: des (pseudofs part)
MFC after: 3 days

The clear_remove() and clear_inodedeps() call vn_start_write(NULL, &mp,
V_NOWAIT) on the non-busied mount point. Unmount might free ufs-specific
mp data, causing ffs_vgetf() to access freed memory.

Busy mountpoint before dropping softdep lk.

Noted and reviewed by: tegge
Tested by: pho
MFC after: 1 week

When a UFS node is truncated to the zero length, e.g. by explicit
truncate(2) call, or by being removed or truncated on open, either
new softupdate freeblks structure is allocated to track the freed
blocks of the node, or truncation is done syncronously when too many SU
dependencies are accumulated. The decision does not take into account
the allocated freeblks dependencies, allowing workloads that do huge
amount of truncations to exhaust the kernel memory.

Take the number of allocated freeblks into consideration for
softdep_slowdown().

Reported by: pluknet gmail com
Diagnosed and tested by: pho
Approved by: re (rwatson)
MFC after: 1 month

Fix fpathconf(3) on fifos, in effect making ls(1) properly
display '+' on them. Taken from kern/125613, with cosmetic
changes.

PR: kern/125613
Submitted by: Jaakko Heinonen <jh at saunalahti dot fi>
Approved by: re (kib)

In vn_vget_ino() and their inline equivalents, mnt_ref() the mount point
around the sequence that drop vnode lock and then busies the mount point.
Not having vlocked node or direct reference to the mp allows for the
forced unmount to proceed, making mp unmounted or reused.

Tested by: pho
Reviewed by: jeff
Approved by: re (kensmith)
MFC after: 2 weeks

Don't panic on attempt to set ACL on a block device file.
This is just a part of kern/125613.

PR: kern/125613
Submitted by: Jaakko Heinonen <jh at saunalahti dot fi>
Reviewed by: rwatson
Approved by: re (kib)

For SU mounts, softdep_fsync() might drop vnode lock, allowing other
threads to put dirty buffers on the vnode bufobj list. For regular files
and synchronous fsync requests, check for the condition and restart the
fsync vop if a new dirty buffer arrived.

Tested by: pho
Approved by: re (kensmith)
MFC after: 1 month

Softdep_fsync() may need to lock parent directory of the synced vnode.
Use inlined (due to FFSV_FORCEINSMQ) version of vn_vget_ino() to prevent
mountpoint from being unmounted and freed while no vnodes are locked.

Tested by: pho
Approved by: re (kensmith)
MFC after: 1 month

Fix a bug reported by pho@ where one can induce a panic by decreasing
vfs.ufs.dirhash_maxmem below the current amount of memory used by dirhash. When
ufsdirhash_build() is called with the memory in use greater than dirhash_maxmem,
it attempts to free up memory by calling ufsdirhash_recycle(). If successful in
freeing enough memory, ufsdirhash_recycle() leaves the dirhash list locked. But
at this point in ufsdirhash_build(), the list is not explicitly unlocked after
the call(s) to ufsdirhash_recycle(). When we next attempt to lock the dirhash
list, we will get a "panic: _mtx_lock_sleep: recursed on non-recursive mutex
dirhash list".

Tested by: pho
Approved by: dwmalone (mentor)
MFC after: 3 weeks

Rework the credential code to support larger values of NGROUPS and
NGROUPS_MAX, eliminate ABI dependencies on them, and raise the to 1024
and 1023 respectively. (Previously they were equal, but under a close
reading of POSIX, NGROUPS_MAX was defined to be too large by 1 since it
is the number of supplemental groups, not total number of groups.)

The bulk of the change consists of converting the struct ucred member
cr_groups from a static array to a pointer. Do the equivalent in
kinfo_proc.

Introduce new interfaces crcopysafe() and crsetgroups() for duplicating
a process credential before modifying it and for setting group lists
respectively. Both interfaces take care for the details of allocating
groups array. crsetgroups() takes care of truncating the group list
to the current maximum (NGROUPS) if necessary. In the future,
crsetgroups() may be responsible for insuring invariants such as sorting
the supplemental groups to allow groupmember() to be implemented as a
binary search.

Because we can not change struct xucred without breaking application
ABIs, we leave it alone and introduce a new XU_NGROUPS value which is
always 16 and is to be used or NGRPS as appropriate for things such as
NFS which need to use no more than 16 groups. When feasible, truncate
the group list rather than generating an error.

Minor changes:
- Reduce the number of hand rolled versions of groupmember().
- Do not assign to both cr_gid and cr_groups[0].
- Modify ipfw to cache ucreds instead of part of their contents since
they are immutable once referenced by more than one entity.

Submitted by: Isilon Systems (initial implementation)
X-MFC after: never
PR: bin/113398 kern/133867

Keep dirhash tailq locked throughout the entirety of ufsdirhash_destroy() to fix
a potential race pointed out by pjd. Also use TAILQ_FOREACH_SAFE to iterate over
dirhashes in ufsdirhash_lowmem(), so that we can continue iterating even after a
dirhash is destroyed.

Suggested by: pjd
Tested by: pho
Approved by: dwmalone (mentor)

Do not use casts (int *)0 and (struct thread *)0 for the arguments of
vn_rdwr, use NULL.

Reviewed by: jhb
MFC after: 1 week

Move "options MAC" from opt_mac.h to opt_global.h, as it's now in GENERIC
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.

Discussed with: pjd

Add vm_lowmem event handler for dirhash. This will cause dirhashes to be
deleted when the system is low on memory. This ought to allow an increase to
vfs.ufs.dirhash_maxmem on machines that have lots of memory, without
degrading performance by having too much memory reserved for dirhash when
other things need it. The default value for dirhash_maxmem is being kept at
2MB for now, though.

This work was mostly done during the 2008 Google Summer of Code.

Approved by: dwmalone (mentor), re
MFC after: 3 months

Handle lock recursion differenty by always checking against LO_RECURSABLE
instead the lock own flag itself.

Tested by: pho

Add hierarchical jails. A jail may further virtualize its environment
by creating a child jail, which is visible to that jail and to any
parent jails. Child jails may be restricted more than their parents,
but never less. Jail names reflect this hierarchy, being MIB-style
dot-separated strings.

Every thread now points to a jail, the default being prison0, which
contains information about the physical system. Prison0's root
directory is the same as rootvnode; its hostname is the same as the
global hostname, and its securelevel replaces the global securelevel.
Note that the variable "securelevel" has actually gone away, which
should not cause any problems for code that properly uses
securelevel_gt() and securelevel_ge().

Some jail-related permissions that were kept in global variables and
set via sysctls are now per-jail settings. The sysctls still exist for
backward compatibility, used only by the now-deprecated jail(2) system
call.

Approved by: bz (mentor)

Make 'struct acl' larger, as required to support NFSv4 ACLs. Provide
compatibility interfaces in both kernel and libc.

Reviewed by: rwatson

Introduce vfs_bio_set_valid() and use it from ffs_realloccg(). This
eliminates the misuse of vfs_bio_clrbuf() by ffs_realloccg().

In collaboration with: tegge

Remove the thread argument from the FSD (File-System Dependent) parts of
the VFS. Now all the VFS_* functions and relating parts don't want the
context as long as it always refers to curthread.

In some points, in particular when dealing with VOPs and functions living
in the same namespace (eg. vflush) which still need to be converted,
pass curthread explicitly in order to retain the old behaviour.
Such loose ends will be fixed ASAP.

While here fix a bug: now, UFS_EXTATTR can be compiled alone without the
UFS_EXTATTR_AUTOSTART option.

VFS KPI is heavilly changed by this commit so thirdy parts modules needs
to be recompiled. Bump __FreeBSD_version in order to signal such
situation.

Do not embed struct ucred into larger netcred parent structures.

Credential might need to hang around longer than its parent and be used
outside of mnt_explock scope controlling netcred lifetime. Use separate
reference-counted ucred allocated separately instead.

While there, extend mnt_explock coverage in vfs_stdexpcheck and clean-up
some unused declarations in new NFS code.

Reported by: John Hickey
PR: kern/133439
Reviewed by: dfr, kib

Change the semantics of i_modrev/va_filerev to what is required for
the nfsv4 Change attribute. There are 2 changes:
1 - The value now changes on metadata changes as well as data
modifications (incremented for IN_CHANGE instead of IN_UPDATE).
2 - It is now saved in spare space in the on-disk i-node so that it
survives a crash.
Since va_filerev is not passed out into user space, the only current
use of va_filerev is in the nfs server, which uses it as the directory
cookie verifier. Since this verifier is only passed back to the server
by a client verbatim and then the server doesn't check it, changing the
semantics should not break anything currently in FreeBSD.

Reviewed by: bde
Approved by: kib (mentor)

In ufs_checkpath(), recheck that '..' still points to the inode with
the same inode number after VFS_VGET() and relock of the vp. If '..'
changed, redo the lookup. To reduce code duplication, move the code to
read '..' dirent into the static helper function ufs_dir_dd_ino().

Supply the source inode number as an argument to ufs_checkpath() instead
of the source inode itself. The inode is unlocked, thus it might be
reclaimed, causing accesses to the freed memory.

Use vn_vget_ino() to get the '..' vnode by its inode number, instead of
directly code VFS_VGET() and relock, to properly busy the mount point
while vp lock is dropped.

Noted and reviewed by: tegge
Tested by: pho
MFC after: 1 month

When verifying '..' after VFS_VGET() in ufs_lookup(), do not return
error if '..' is still there but changed between lookup and check.
Start relookup instead. Rename is supposed to change '..' reference
atomically, so transient failures introduced by r191137 are wrong.

While rearranging the code to allow lookup restart in ufs_lookup(),
remove the comment that only distracts the reader.

Noted and reviewed by: tegge
Also reported by: pho
MFC after: 1 month

Use acl_alloc() and acl_free() instead of using uma(9) directly.
This will make switching to malloc(9) easier; also, it would be
neccessary to add these routines if/when we implement variable-size
ACLs.

Verify that '..' still exists with the same inode number after
VFS_VGET() has returned in ufs_lookup(). If the '..' lookup started
immediately before the parent directory was removed, we might return
either cleared or unrelated inode otherwise.

Ufs_lookup() is split into new function ufs_lookup_() that either does
lookup, or verifies that directory entry exists and references supplied
inode number.

Reviewed by: tegge
Tested by: pho,
Andreas Tobler <andreast-list fgznet ch> (previous version)
MFC after: 1 month

Remove VOP_LEASE and supporting functions. This hasn't been used since
the removal of NQNFS, but was left in in case it was required for NFSv4.
Since our new NFSv4 client and server can't use it for their
requirements, GC the old mechanism, as well as other unused lease-
related code and interfaces.

Due to its impact on kernel programming and binary interfaces, this
change should not be MFC'd.

Proposed by: jeff
Reviewed by: jeff
Discussed with: rmacklem, zach loafman @ isilon

When removing or renaming snaphost, do not delve into request_cleanup().
The later may need blocks from the underlying device that belongs
to normal files, that should not be locked while snap lock is held.

Reported and tested by: pho
MFC after: 1 month

Correct typo.

Noted by: kensmith

Fix two issues with bufdaemon, often causing the processes to hang in
the "nbufkv" sleep.

First, ffs background cg group block write requests a new buffer for
the shadow copy. When ffs_bufwrite() is called from the bufdaemon due
to buffers shortage, requesting the buffer deadlock bufdaemon.
Introduce a new flag for getnewbuf(), GB_NOWAIT_BD, to request getblk
to not block while allocating the buffer, and return failure
instead. Add a flag argument to the geteblk to allow to pass the flags
to getblk(). Do not repeat the getnewbuf() call from geteblk if buffer
allocation failed and either GB_NOWAIT_BD is specified, or geteblk()
is called from bufdaemon (or its helper, see below). In
ffs_bufwrite(), fall back to synchronous cg block write if shadow
block allocation failed.

Since r107847, buffer write assumes that vnode owning the buffer is
locked. The second problem is that buffer cache may accumulate many
buffers belonging to limited number of vnodes. With such workload,
quite often threads that own the mentioned vnodes locks are trying to
read another block from the vnodes, and, due to buffer cache
exhaustion, are asking bufdaemon for help. Bufdaemon is unable to make
any substantial progress because the vnodes are locked.

Allow the threads owning vnode locks to help the bufdaemon by doing
the flush pass over the buffer cache before getnewbuf() is going to
uninterruptible sleep. Move the flushing code from buf_daemon() to new
helper function buf_do_flush(), that is called from getnewbuf(). The
number of buffers flushed by single call to buf_do_flush() from
getnewbuf() is limited by new sysctl vfs.flushbufqtarget. Prevent
recursive calls to buf_do_flush() by marking the bufdaemon and threads
that temporarily help bufdaemon by TDP_BUFNEED flag.

In collaboration with: pho
Reviewed by: tegge (previous version)
Tested by: glebius, yandex ...
MFC after: 3 weeks

The non-modifying EA VOPs are executed with only shared vnode lock taken.
Provide a custom lock around initializing and tearing down EA area,
to prevent both memory leaks and double-free of it. Count the number
of EA area accessors.

Lock protocol requires either holding exclusive vnode lock to modify
i_ea_area, or shared vnode lock and owning IN_EA_LOCKED flag in i_flag.

Noted by: YAMAMOTO, Taku <taku tackymt homeip net>
Tested by: pho (previous version)
MFC after: 2 weeks

Do not double-free the struct inode when insmntque failed. Default
insmntque destructor reclaims the vnode, and ufs_reclaim frees the memory.

Reviewed by: tegge
MFC after: 3 days

Add a new internal mount flag (MNTK_EXTENDED_SHARED) to indicate that a
filesystem supports additional operations using shared vnode locks.
Currently this is used to enable shared locks for open() and close() of
read-only file descriptors.
- When an ISOPEN namei() request is performed with LOCKSHARED, use a
shared vnode lock for the leaf vnode only if the mount point has the
extended shared flag set.
- Set LOCKSHARED in vn_open_cred() for requests that specify O_RDONLY but
not O_CREAT.
- Use a shared vnode lock around VOP_CLOSE() if the file was opened with
O_RDONLY and the mountpoint has the extended shared flag set.
- Adjust md(4) to upgrade the vnode lock on the vnode it gets back from
vn_open() since it now may only have a shared vnode lock.
- Don't enable shared vnode locks on FIFO vnodes in ZFS and UFS since
FIFO's require exclusive vnode locks for their open() and close()
routines. (My recent MPSAFE patches for UDF and cd9660 already included
this change.)
- Enable extended shared operations on UFS, cd9660, and UDF.

Submitted by: ups
Reviewed by: pjd (ZFS bits)
MFC after: 1 month

Adjust some variables (mostly related to the buffer cache) that hold
address space sizes to be longs instead of ints. Specifically, the follow
values are now longs: runningbufspace, bufspace, maxbufspace,
bufmallocspace, maxbufmallocspace, lobufspace, hibufspace, lorunningspace,
hirunningspace, maxswzone, maxbcache, and maxpipekva. Previously, a
relatively small number (~ 44000) of buffers set in kern.nbuf would result
in integer overflows resulting either in hangs or bogus values of
hidirtybuffers and lodirtybuffers. Now one has to overflow a long to see
such problems. There was a check for a nbuf setting that would cause
overflows in the auto-tuning of nbuf. I've changed it to always check and
cap nbuf but warn if a user-supplied tunable would cause overflow.

Note that this changes the ABI of several sysctls that are used by things
like top(1), etc., so any MFC would probably require a some gross shims
to allow for that.

MFC after: 1 month

Right now, when trying to unmount a device that's already gone,
msdosfs_unmount() and ffs_unmount() exit early after getting ENXIO.
However, dounmount() treats ENXIO as a success and proceeds with
unmounting. In effect, the filesystem gets unmounted without closing
GEOM provider etc.

Reviewed by: kib
Approved by: rwatson (mentor)
Tested by: dho
Sponsored by: FreeBSD Foundation

Refactor, moving error checking outside of the
'if (mp->mnt_flag & MNT_SOFTDEP)' conditional. No functional
changes.

Reviewed by: kib
Approved by: rwatson (mentor)
Tested by: pho
Sponsored by: FreeBSD Foundation

- If the g_access() call for the initial root mount fails, then fully
cleanup. Before the GEOM consumer would not have been closed.
- Bump the reference on the character device being mounted while the
associated devfs vnode is locked.

Reviewed by: kib

When a device containing mounted UFS filesystem disappears, the type
of devvp becomes VBAD, which UFS incorrectly interprets as snapshot
vnode, which in turns causes panic. Fix it by replacing '!= VCHR'
with '== VREG'.

With this fix in place, you should no longer be able to panic the system
by removing a device with an UFS filesystem mounted from it - assuming
you don't use softupdates.

Reviewed by: kib
Tested by: pho
Approved by: rwatson (mentor)
Sponsored by: FreeBSD Foundation

Make sure the cdev doesn't go away while the filesystem is still mounted.
Otherwise dev2udev() could return garbage.

Reviewed by: kib
Approved by: rwatson (mentor)
Sponsored by: FreeBSD Foundation

Following a fair amount of real world experience with ACLs and
extended attributes since FreeBSD 5, make the following semantic
changes:

- Don't update the inode modification time (mtime) when extended
attributes (and hence also ACLs) are added, modified, or removed.
- Don't update the inode access tie (atime) when extended attributes
(and hence also ACLs) are queried.

This means that rsync (and related tools) won't improperly think
that the data in the file has changed when only the ACL has changed.

Note that ffs_reallocblks() has not been changed to not update on an
IO_EXT transaction, but currently EAs don't use the cluster write
routines so this shouldn't be a problem. If EAs grow support for
clustering, then VOP_REALLOCBLKS() will need to grow a flag argument
to carry down IO_EXT to UFS.

MFC after: 1 week
PR: ports/125739
Reported by: Alexander Zagrebin <alexz@visp.ru>
Tested by: pluknet <pluknet@gmail.com>,
Greg Byshenk <freebsd@byshenk.net>
Discussed with: kib, kientzle, timur, Alexander Bokovoy <ab@samba.org>

Fix a few style bogons.

Submitted by: bde

Move the code from ufs_lookup.c used to do dotdot lookup, into
the helper function. It is supposed to be useful for any filesystem
that has to unlock dvp to walk to the ".." entry in lookup routine.

Requested by: jhb
Tested by: pho
MFC after: 1 month

Move the VA_MARKATIME flag for VOP_SETATTR() out into its own VOP:
VOP_MARKATIME() since unlike the rest of VOP_SETATTR(), VA_MARKATIME
can be performed while holding a shared vnode lock (the same functionality
is done internally by VOP_READ which can run with a shared vnode lock).
Add missing locking of the vnode interlock to the ufs implementation and
remove a special note and test from the NFS client about not supporting the
feature.

Inspired by: ups
Tested by: pho

The r187467 should remove all pages for V_NORMAL case too, because
indirect block pages are not removed by the mentioned invocation of
the vnode_pager_setsize().

Put a common code into the helper function ffs_pages_remove().

Reported and tested by: dchagin
Reviewed by: ups
MFC after: 3 weeks

Add a comment explaining why the "bufwait" / "dirhash" LOR reported by
WITNESS will not actually result in a deadlock.

Discussed with: kib
MFC after: 1 week

When extending inode size, we call vnode_pager_setsize(), to have a
address space where to put vnode pages, and then call UFS_BALLOC(),
to actually allocate new block and map it. When UFS_BALLOC() returns
error, sometimes we forget to revert the vm object size increase,
allowing for the pages that are not backed by the logical disk blocks.

Revert vnode_pager_setsize() back when UFS_BALLOC() failed, for
ffs_truncate() and ffs_write().

PR: 129956
Reviewed by: ups
MFC after: 3 weeks

FFS puts the extended attributes blocks at the negative blocks for the
vnode, from -1 down. When vinvalbuf(vp, V_ALT) is done for the vnode, it
incorrectly does vm_object_page_remove(0, 0), removing all pages from
the underlying vm object, not only the pages that back the extended
attributes data.

Change vinvalbuf() to not remove any pages from the object when
V_NORMAL or V_ALT are specified. Instead, the only in-tree caller
in ffs_inode.c:ffs_truncate() that specifies V_ALT explicitely
removes the corresponding page range. The V_NORMAL caller
does vnode_pager_setsize(vp, 0) immediately after the call to
vinvalbuf(V_NORMAL) already.

Reported by: csjp
Reviewed by: ups
MFC after: 3 weeks

Lock the uepm_lock around the autostart of extattrs.

Reported and tested by: pho
Reviewed by: rwatson
MFC after: 3 weeks

If unmount of the ffs mp failed, reinitialize the extended attributes
for the mp, and restart them if autostart is enabled.

Reported and tested by: pho
Reviewed by: rwatson
MFC after: 3 weeks

Do not busy twice the mount point where a quota operation is performed.

Tested by: pho
MFC after: 1 month

According to phk@, VOP_STRATEGY should never, _ever_, return
anything other than 0. Make it so. This fixes
"panic: VOP_STRATEGY failed bp=0xc320dd90 vp=0xc3b9f648",
encountered when writing to an orphaned filesystem. Reason
for the panic was the following assert:
KASSERT(i == 0, ("VOP_STRATEGY failed bp=%p vp=%p", bp, bp->b_vp));
at vfs_bio:bufstrategy().

Reviewed by: scottl, phk
Approved by: rwatson (mentor)
Sponsored by: FreeBSD Foundation

The dqrele() function syncs the dq, then acquires the dqh lock, and then
does final drop of the the dq reference to put it onto the free list.
There is a possibility that the dq would be found by another thread
after sync and before the dqh lock is acquired. If that other thread
drops the dq before we have taken the dqh lock, the dirty dq is put on
the free list.

Recheck the DQ_MOD after the dqh lock is relocked. Repeat dqsync() if
the dq is dirty. This ensures that up to date dq is written in the quota
file and fixes assertion in dqget().

Reported and tested by: Frode Nordahl <frode nordahl net>
MFC after: 3 days

Improve usefulness of the panic by printing the pointer to the problematic
dquot. In-tree gdb is often unable to get the dq value, so supply it in
panic message.

MFC after: 3 days

Do not lock vnode interlock around reading of v_iflag to check VI_DOOMED.
Read of the pointer is atomic, and flag cannot be set while vnode lock
is held.

Requested by: jhb
MFC after: 1 month

Busy ufs filesystem around block of code that does ".." lookup. Since
mnt_lock is before lock of any vnode on the mp, it uses LK_NOWAIT. Since
MNTK_UNMOUNT may be transient, pdp lock is dropped when vfs_busy()
failed, and operation is retried after some time. This way, ffs_vget()
is not called on the mp that may be in the process of being destroyed by
unmount.

Check for the VI_DOOMED flag on pdp after its lock is reacquired, to
better detect some situations where directory containing ".."
entry is removed during the lookup.

Reviewed by: tegge, attilio (previous version)
Tested by: pho
MFC after: 1 month

Fix typo.

For now on every 10 cyclinder groups flush the buffer cache to free
up space. If the buffer cache fills up then the disk systems can
grind to a halt. Better tuning can be figured out later.

Tested by: Tim, others and work
Reviewed by: Kostik Belousov
PR: 128832

Quiet a WITNESS warning with the dirhash sx locks by setting the DUPOK
flag. Specifically, if two threads race to create a dirhash for a
directory, then one might already have created a private dirhash
structure (and locked it) when it realizes the directory now has a
structure and tries to lock that one.

In UFS, when reading EA that contains ACL fails for some reason, include
inode number and filesystem name, so the administrator can fix the problem.

Approved by: rwatson (mentor)

Improve VFS locking:
- Implement real draining for vfs consumers by not relying on the
mnt_lock and using instead a refcount in order to keep track of lock
requesters.
- Due to the change above, remove the mnt_lock lockmgr because it is now
useless.
- Due to the change above, vfs_busy() is no more linked to a lockmgr.
Change so its KPI by removing the interlock argument and defining 2 new
flags for it: MBF_NOWAIT which basically replaces the LK_NOWAIT of the
old version (which was unlinked from the lockmgr alredy) and
MBF_MNTLSTLOCK which provides the ability to drop the mountlist_mtx
once the mnt interlock is held (ability still desired by most consumers).
- The stub used into vfs_mount_destroy(), that allows to override the
mnt_ref if running for more than 3 seconds, make it totally useless.
Remove it as it was thought to work into older versions.
If a problem of "refcount held never going away" should appear, we will
need to fix properly instead than trust on such hackish solution.
- Fix a bug where returning (with an error) from dounmount() was still
leaving the MNTK_MWAIT flag on even if it the waiters were actually
woken up. Just a place in vfs_mount_destroy() is left because it is
going to recycle the structure in any case, so it doesn't matter.
- Remove the markercnt refcount as it is useless.

This patch modifies VFS ABI and breaks KPI for vfs_busy() so manpages and
__FreeBSD_version will be modified accordingly.

Discussed with: kib
Tested by: pho

Introduce accmode_t. This is required for NFSv4 ACLs - it will be neccessary
to add more V* constants, and the variables changed by this patch were often
being assigned to mode_t variables, which is 16 bit.

Approved by: rwatson (mentor)

Provide an explanation for getinoquota() call in the ufs_access vop.

MFC after: 3 days

Fix a number of style issues in the MALLOC / FREE commit. I've tried to
be careful not to fix anything that was already broken; the NFSv4 code is
particularly bad in this respect.

Retire the MALLOC and FREE macros. They are an abomination unto style(9).

MFC after: 3 months

Assert that v_holdcnt is non-zero before entering lockmgr in vn_lock
and ffs_lock. This cannot catch situations where holdcnt is incremented
not by curthread, but I think it is useful.

Reviewed by: tegge, attilio
Tested by: pho
MFC after: 2 weeks

Sync up summary information for cylinder groups while data is already
in memory during snapshot creation. This improves the results of the
background fsck.

Submitted by: tegge
MFC after: 1 week

Remove the struct thread unuseful argument from bufobj interface.
In particular following functions KPI results modified:
- bufobj_invalbuf()
- bufsync()

and BO_SYNC() "virtual method" of the buffer objects set.
Main consumers of bufobj functions are affected by this change too and,
in particular, functions which changed their KPI are:
- vinvalbuf()
- g_vfs_close()

Due to the KPI breakage, __FreeBSD_version will be bumped in a later
commit.

As a side note, please consider just temporary the 'curthread' argument
passing to VOP_SYNC() (in bufsync()) as it will be axed out ASAP

Reviewed by: kib
Tested by: Giovanni Trematerra <giovanni dot trematerra at gmail dot com>

Enable shared lookups on UFS. There are some remaining issues with forced
unmounts, but those are in the VFS lookup code are not UFS specific.

Tested by: pho, kris

Close a race between concurrent calls to ufsdirhash_recycle() and
ufsdirhash_free() introduced in my last commit by removing the dirhash
about to be free'd in ufsdirhash_free() from the global dirhash list
before dropping the sx lock.

Tested by: kris

Initialize va_flags and va_filerev properly in VOP_GETATTR(). Don't
initialize va_vaflags and va_spare because they are not part of the
VOP_GETATTR() API. Also don't initialize birthtime to ctime or zero.

Submitted by: Jaakko Heinonen <jh saunalahti fi>
Reviewed by: bde
Discussed on: freebsd-fs
MFC after: 1 month

Retire the 'i_reclen' field from the in-memory i-node. Previously,
during a DELETE lookup operation, lookup would cache the length of the
directory entry to be deleted in 'i_reclen'. Later, the actual VOP to
remove the directory entry (ufs_remove, ufs_rename, etc.) would call
ufs_dirremove() which extended the length of the previous directory
entry to "remove" the deleted entry.

However, we always read the entire block containing the directory
entry when doing the removal, so we always have the directory entry to
be deleted in-memory when doing the update to the directory block.
Also, we already have to figure out where the directory entry that is
being removed is in the block so that we can pass the component name
to the dirhash code to update the dirhash. So, instead of passing
'i_reclen' from ufs_lookup() to the ufs_dirremove() routine, just read
the 'd_reclen' field directly out of the entry being removed when
updating the length of the previous entry in the block.

This avoids a cosmetic issue of writing to 'i_reclen' while holding a
shared vnode lock. It also slightly reduces the amount of side-band
data passed from ufs_lookup() to operations updating a directory via
the directory's i-node.

Reviewed by: jeff

Fix a race with shared lookups on UFS. If the the dirhash code reached the
cap on memory usage, then shared LOOKUP operations could start free'ing
dirhash structures. Without these fixes, concurrent free's on the same
directory could result in one of the threads blocked on a lock in a dirhash
structure free'd by the other thread.
- Replace the lockmgr lock in the dirhash structure with an sx lock.
- Use a reference count managed with ufsdirhash_hold()/drop() to determine
when to free the dirhash structures. The directory i-node holds a
reference while the dirhash is attached to an i-node. Code that wishes
to lock the dirhash while holding a shared vnode lock must first
acquire a private reference to the dirhash while holding the vnode
interlock before acquiring the dirhash sx lock. After acquiring the sx
lock, it drops the private reference after checking to see if the
dirhash is still used by the directory i-node.

- Only set i_offset in the parent directory's i-node during a lookup for
non-LOOKUP operations.
- Relax a VOP assertion for a DELETE lookup. rename() uses WANTPARENT
instead of LOCKPARENT when looking up the source pathname. ufs_rename()
uses a relookup() to lock the parent directory when it decides to finally
remove the source path. Thus, it is ok for a DELETE with WANTPARENT set
instead of LOCKPARENT to use a shared vnode lock rather than an exclusive
vnode lock.

Reported by: kris (2)
Reviewed by: jeff

vdropl() drops the vnode interlock. Thus, the code in the QUOTA case that
upgrades the vnode lock if it is share locked was dropping the interlock
before actually checking VI_DOOMED. Fix this by do the vdropl() after the
check and relying on it to drop the vnode interlock.

Reported by: pho
Reviewed by: kib
MFC after: 1 week

Suspend the write operations on the UFS filesystem being unmounted or
remounted from rw to ro.

Proposed and reviewed by: tegge
In collaboration with: pho
MFC after: 1 month

When attempt is made to suspend a filesystem that is already syspended,
wait until the current suspension is lifted instead of silently returning
success immediately. The consequences of calling vfs_write() resume when
not owning the suspension are not well-defined at best.

Add the vfs_susp_clean() mount method to be called from
vfs_write_resume(). Set it to process_deferred_inactive() for ffs, and
stop calling it manually.

Add the thread flag TDP_IGNSUSP that allows to bypass the suspension
point in the vn_start_write. It is intended for use by VFS in the
situations where the suspender want to do some i/o requiring calls to
vn_start_write(), and this i/o cannot be done later.

Reviewed by: tegge
In collaboration with: pho
MFC after: 1 month

Add the ffs structures introspection functions for ddb.
Show the b_dep value for the buffer in the show buffer command.
Add a comand to dump the dirty/clean buffer list for vnode.

Reviewed by: tegge
Tested and used by: pho
MFC after: 1 month

When downgrading the read-write mount to read-only, do_unmount() sets
MNT_RDONLY flag before the VFS_MOUNT() is called. In ufs_inactive()
and ufs_itimes_locked(), UFS verifies whether the fs is read-only by
checking MNT_RDONLY, but this may cause loss of the IN_MODIFIED flag
for inode on the fs being remounted rw->ro.

Introduce UFS_RDONLY() struct ufsmount' method that reports the value
of the fs_ronly. The later is set to 1 only after the remount is
finished.

Reviewed by: tegge
In collaboration with: pho
MFC after: 1 month

The struct inode *ip supplied to softdep_freefile is not neccessary the
inode having number ino. In r170991, the ip was marked IN_MODIFIED, that
is not quite correct.

Mark only the right inode modified by checking inode number.

Reviewed by: tegge
In collaboration with: pho
MFC after: 1 month

When calling extattr_check_cred, use V{READ,WRITE}, not I{READ,WRITE}.

Approved by: rwatson (mentor)

Decontextualize vfs_busy(), vfs_unbusy() and vfs_mount_alloc() functions.

Manpages are updated accordingly.

Tested by: Diego Sardina <siarodx at gmail dot com>

Decontextualize the couplet VOP_GETATTR / VOP_SETATTR as the passed thread
was always curthread and totally unuseful.

Tested by: Giovanni Trematerra <giovanni dot trematerra at gmail dot com>

In ffs_valloc(), ffs_vget() may fail because insmntque() refused to
insert new vnode into the mount vnode list. Then, for the SU-enabled
mount, ffs_vfree could create freefile dependency. This dependency can
hang around forever since inode is not marked as IN_MODIFIED and
correspondingly inodeblock may be not marked as dirty.

After ffs_vget() fails, retry with FFSV_FORCEINSMQ, mark the inode as
modified, and vput() it immediately. Take care of the dup alloc.

Tested by: pho
Reviewed by: tegge
MFC after: 1 month

Softdep code may need to instantiate vnode when processing
dependencies. In particular, it may need this while syncing filesystem
being unmounted. Since during unmount MNTK_NOINSMNTQUE flag is set,
that could sometimes disallow insertion of the vnode into the vnode
mount list, softdep code needs to overwrite the MNTK_NOINSMNTQUE flag.

Create the ffs_vgetf() function that sets the VV_FORCEINSMQ flag for
new vnode and use it consistently from the softdep code instead of
ffs_vget().

Add the retry logic to the softdep_flushfiles() to flush the vnodes
that could be instantiated while flushing softdep dependencies.

Tested by: pho, kris
Reviewed by: tegge
MFC after: 1 month

Put the relocked variable from the r182111 into the #ifdef QUOTA braces
to prevent warning about unused var on the !QUOTA kernels.

Reported by: ed
MFC after: 1 week

Revert the r167541: "Remove unneeded getinoquota() call in the
ufs_access()." The call to getinoquota in ufs_access() serves the
purpose of instantiating inode dquot from the vn_open(). Since quotas
are accounted only for the inodes with already attached dquot, removal
of the call prevented opened inodes from participation in the quota
calculations.

Since ufs_access() may be called with the vnode being only shared
locked, upgrade (and then downgrade) vnode lock if calling
getinoquota().

Reported by: simon at optinet com
In collaboration with: pho
MFC after: 1 week

Revert r181345.
Move the NULL pointer check to the vfs_deleteopt() function.

Discussed with: rodrigc
MFC after: 3 days

User may do "mount -o snapshot ...", that causes new FFS mount to be
performed with snapshot option, while the mp->mnt_opt is NULL.
Protect against NULL pointer dereference.

Noted by: Mateusz Guzik <mjguzik gmail com>
MFC after: 3 days

ufsmount.h uses "struct\tfoo *bar;", except where it doesn't.
quota.h uses "struct foo\t*bar;", except where it doesn't.
Try to make them both agree with themselves (though not with eachother)

Whitespace, prototypes

Whitespace tweak.

The ffs_balloc_ufs{1,2} functions call bdwrite() while having several
vnode buffers locked at once. In particular, there are indirect buffers
among locked ones. The bdwrite() may start the flushing to keep dirty
buffer list at the bounds. If any buffer on the dirty list requires
translation from logical to physical block number, code may ends up
trying to lock an indirect buffer already locked in ffs_balloc_ufsX.

Prevent the bdflush() activity when several buffers are locked at once
by setting the TDP_INBDFUSH for the problematic code blocks.

Reported and tested by: pho, Josef Buchsteiner at Juniper
In collaboration with: kan
MFC after: 1 month

Say hi to svn, by simplifing ffs_vget() function a bit - there is no need for
a variable that is used only once.

Fix comments to replace SBSIZE with SBLOCKSIZE, since SBSIZE
was renamed to SBLOCKSIZE in version 1.33

Reviewed by: mckusick

After converting the "snapshot" mount option to the MNT_SNAPSHOT flag,
delete "snapshot" from the persistent mount options list.
This should fix problems with doing a mount -o snapshot of a file system, followed by
an NFS export of the same file system.

PR: 122833
Reported by: Leon Kos <leon.kos lecad fs uni-lj si>,
Jaakko Heinonen <jh saunalahti fi>
MFC after: 1 month

For the following mount options, do not perform the string to flag conversions
here, because we already do them further up in vfs_donmount() in vfs_mount.c

async -> MNT_ASYNC
force -> MNT_FORCE
multilabel -> MNT_MULTILABEL
noatime -> MNT_NOATIME
noclusterr -> MNT_NOCLUSTERR
noclusterw -> MNT_NOCLUSTERW

MFC after: 1 month

Allow VM object creation in ufs_lookup. (If vfs.vmiodirenable is set)
Directory IO without a VM object will store data in 'malloced' buffers
severely limiting caching of the data. Without this change VM objects for
directories are only created on an open() of the directory.
TODO: Inline test if VM object already exists to avoid locking/function call
overhead.

Tested by: kris@
Reviewed by: jeff@
Reported by: David Filo

- Use a local variable for i_ino in ufs_lookup. It is only used to
communicate between two parts of this one function. This was causing
problems with shared lookups as each would trash the ino value in the
inode.
- Remove the unused i_ino field from the inode structure.

Move the head of byte-level advisory lock list from the
filesystem-specific vnode data to the struct vnode. Provide the
default implementation for the vop_advlock and vop_advlockasync.
Purge the locks on the vnode reclaim by using the lf_purgelocks().
The default implementation is augmented for the nfs and smbfs.
In the nfs_advlock, push the Giant inside the nfs_dolock.

Before the change, the vop_advlock and vop_advlockasync have taken the
unlocked vnode and dereferenced the fs-private inode data, racing with
with the vnode reclamation due to forced unmount. Now, the vop_getattr
under the shared vnode lock is used to obtain the inode size, and
later, in the lf_advlockasync, after locking the vnode interlock, the
VI_DOOMED flag is checked to prevent an operation on the doomed vnode.

The implementation of the lf_purgelocks() is submitted by dfr.

Reported by: kris
Tested by: kris, pho
Discussed with: jeff, dfr
MFC after: 2 weeks

- Use a lockmgr lock rather than a mtx to protect dirhash. This lock
may be held for the duration of the various dirhash operations which
avoids many complex unlock/lock/revalidate sequences.
- Permit shared locks on lookup. To protect the ip->i_dirhash pointer we
use the vnode interlock in the shared case. Callers holding the
exclusive vnode lock can run without fear of concurrent modification to
i_dirhash.
- Hold an exclusive dirhash lock when creating the dirhash structure for
the first time or when re-creating a dirhash structure which has been
recycled.

Tested by: kris, pho

- cache dp->i_offset in the local 'i_offset' variable for use in loop
indexes so directory lookup becomes shared lock safe. In the modifying
cases an exclusive lock is held here so the commit routine may
rely on the state of i_offset.
- Similarly handle i_diroff by fetching at the start and setting only once
the operation is complete. Without the exclusive lock these are only
considered hints.
- Assert that an exclusive lock is held when we're preparing for a commit
routine.
- Honor the lock type request from lookup instead of always using exclusive
locking.

Tested by: pho, kris

Correct function name in panic().

Reported by: kensmith

Optimize lockmgr in order to get rid of the pool mutex interlock, of the
state transitioning flags and of msleep(9) callings.
Use, instead, an algorithm very similar to what sx(9) and rwlock(9)
alredy do and direct accesses to the sleepqueue(9) primitive.

In order to avoid writer starvation a mechanism very similar to what
rwlock(9) uses now is implemented, with the correspective per-thread
shared lockmgrs counter.

This patch also adds 2 new functions to lockmgr KPI: lockmgr_rw() and
lockmgr_args_rw(). These two are like the 2 "normal" versions, but they
both accept a rwlock as interlock. In order to realize this, the general
lockmgr manager function "__lockmgr_args()" has been implemented through
the generic lock layer. It supports all the blocking primitives, but
currently only these 2 mappers live.

The patch drops the support for WITNESS atm, but it will be probabilly
added soon. Also, there is a little race in the draining code which is
also present in the current CVS stock implementation: if some sharers,
once they wakeup, are in the runqueue they can contend the lock with
the exclusive drainer. This is hard to be fixed but the now committed
code mitigate this issue a lot better than the (past) CVS version.
In addition assertive KA_HELD and KA_UNHELD have been made mute
assertions because they are dangerous and they will be nomore supported
soon.

In order to avoid namespace pollution, stack.h is splitted into two
parts: one which includes only the "struct stack" definition (_stack.h)
and one defining the KPI. In this way, newly added _lockmgr.h can
just include _stack.h.

Kernel ABI results heavilly changed by this commit (the now committed
version of "struct lock" is a lot smaller than the previous one) and
KPI results broken by lockmgr_rw() / lockmgr_args_rw() introduction,
so manpages and __FreeBSD_version will be updated accordingly.

Tested by: kris, pho, jeff, danger
Reviewed by: jeff
Sponsored by: Google, Summer of Code program 2007

Add the support for the AT_FDCWD and fd-relative name lookups to the
namei(9).

Based on the submission by rdivacky,
sponsored by Google Summer of Code 2007
Reviewed by: rwatson, rdivacky
Tested by: pho

- Since rev 1.142 of ffs_snapshot.c the interlock has not been required
to protect the v_lock pointer. Removing the interlock acquisition
here allows vn_lock() to proceed without requiring the interlock
at all.
- If the lock mutated while we were sleeping on it the interlock has
been dropped. It is conceivable that the upper layer code was
relying on the interlock and LK_NOWAIT to protect the identity or
state of the vnode while acquiring the lock. In this case return
EBUSY rather than trying the new lock to prevent potential races.

Reviewed by: tegge

- Don't free snapdata structures when they are no longer in use.
Keeping the lockmgr lock valid allows us to switch the v_lock pointer
in snapshot vnodes between the embedded lockmgr lock and snapdata
lock without needing the vnode interlock to protect against races
- Keep unused snapdata structures in a list.
- Add a function to lock the devvp and allocate a snapdata to it or
acquire a new one without races. The old function was safe from
creation races because we set the mount flag when creating snapshots
and thus serializing them. However, it might have been subject to
destroying races.

Reviewed by: tegge

Fix a nit with the 'nofoo' options where 'foo' is mapped to 'nonofoo'
(such as 'atime' vs 'noatime'). The filesystems will always see either
'nofoo' or 'nonofoo', never plain 'foo'. As such, their list of valid
mount options should include 'nofoo' instead of 'foo'. With this fix,
you can do 'mount -u -o atime' on a FFS filesystem that isn't marked as
noatime without getting an error. You can also update a noatime FFS
filesystem mounted via mount(2) (e.g. 6.x /sbin/mount binary) to 'atime'
using nmount(2) (e.g. 7.x /sbin/mount binary).

MFC after: 1 week
Reviewed by: crodig

Add the new kernel-mode NFS Lock Manager. To use it instead of the
user-mode lock manager, build a kernel with the NFSLOCKD option and
add '-k' to 'rpc_lockd_flags' in rc.conf.

Highlights include:

* Thread-safe kernel RPC client - many threads can use the same RPC
client handle safely with replies being de-multiplexed at the socket
upcall (typically driven directly by the NIC interrupt) and handed
off to whichever thread matches the reply. For UDP sockets, many RPC
clients can share the same socket. This allows the use of a single
privileged UDP port number to talk to an arbitrary number of remote
hosts.

* Single-threaded kernel RPC server. Adding support for multi-threaded
server would be relatively straightforward and would follow
approximately the Solaris KPI. A single thread should be sufficient
for the NLM since it should rarely block in normal operation.

* Kernel mode NLM server supporting cancel requests and granted
callbacks. I've tested the NLM server reasonably extensively - it
passes both my own tests and the NFS Connectathon locking tests
running on Solaris, Mac OS X and Ubuntu Linux.

* Userland NLM client supported. While the NLM server doesn't have
support for the local NFS client's locking needs, it does have to
field async replies and granted callbacks from remote NLMs that the
local client has contacted. We relay these replies to the userland
rpc.lockd over a local domain RPC socket.

* Robust deadlock detection for the local lock manager. In particular
it will detect deadlocks caused by a lock request that covers more
than one blocking request. As required by the NLM protocol, all
deadlock detection happens synchronously - a user is guaranteed that
if a lock request isn't rejected immediately, the lock will
eventually be granted. The old system allowed for a 'deferred
deadlock' condition where a blocked lock request could wake up and
find that some other deadlock-causing lock owner had beaten them to
the lock.

* Since both local and remote locks are managed by the same kernel
locking code, local and remote processes can safely use file locks
for mutual exclusion. Local processes have no fairness advantage
compared to remote processes when contending to lock a region that
has just been unlocked - the local lock manager enforces a strict
first-come first-served model for both local and remote lockers.

Sponsored by: Isilon Systems
PR: 95247 107555 115524 116679
MFC after: 2 weeks

Yield the cpu in the kernel while iterating the list of the
vnodes belonging to the mountpoint. Also, yield when in the
softdep_process_worklist() even when we are not going to sleep due to
buffer drain.

It is believed that the ULE fixed the problem [1], but the yielding
seems to be needed at least for the 4BSD case.

Discussed: on stable@, with bde
Reviewed by: tegge, jeff [1]
MFC after: 2 weeks

- Complete part of the unfinished bufobj work by consistently using
BO_LOCK/UNLOCK/MTX when manipulating the bufobj.
- Create a new lock in the bufobj to lock bufobj fields independently.
This leaves the vnode interlock as an 'identity' lock while the bufobj
is an io lock. The bufobj lock is ordered before the vnode interlock
and also before the mnt ilock.
- Exploit this new lock order to simplify softdep_check_suspend().
- A few sync related functions are marked with a new XXX to note that
we may not properly interlock against a non-zero bv_cnt when
attempting to sync all vnodes on a mountlist. I do not believe this
race is important. If I'm wrong this will make these locations easier
to find.

Reviewed by: kib (earlier diff)
Tested by: kris, pho (earlier diff)

Reduce the acquisition of the vnode interlock in the ffs_read() and
ffs_extread() when setting the IN_ACCESS flag by checking whether the
IN_ACCESS is already set. The possible race there is admissible.

Tested by: pho
Submitted by: jeff

- Relax requirements for p_numthreads, p_threads, p_swtick, and p_nice from
requiring the per-process spinlock to only requiring the process lock.
- Reflect these changes in the proc.h documentation and consumers throughout
the kernel. This is a substantial reduction in locking cost for these
fields and was made possible by recent changes to threading support.

In keeping with style(9)'s recommendations on macros, use a ';'
after each SYSINIT() macro invocation. This makes a number of
lightweight C parsers much happier with the FreeBSD kernel
source, including cflow's prcc and lxr.

MFC after: 1 month
Discussed with: imp, rink

Replace the non-MPSAFE timeout(9) API in ffs_softdep.c with the MPSAFE
callout_* API (e.g. callout_init_mtx(9)). This was one of the numerous
items on the http://wiki.freebsd.org/SMPTODO list.

Reviewed by: imp, obrien, jhb
MFC after: 1 week

Remove include of opt_quota.h; as of revision 1.205 there is no longer
any #ifdef QUOTA conditional code.

Initialize mnt_stat.f_iosize before autostarting UFS1 extattrs.
It is normally initialized by ffs_statfs() after ffs_mount finished.

The extattr autostart code calls the ufs_lookup(), that uses value above
to iterate over the directory blocks, see bmask initialization in the
ufs_lookup() and ufsdirhash. Having the filesystem with root directory
spanning more then one block would result in reading a random kernel
memory.

PR: kern/120781
Test case provided by: rwatson
MFC after: 1 week

Continue on-going campaign to replace lockmgr locks with sx locks where
the specific semantics of ockmgr aren't required: update UFS1 extended
attributes to protect its data structures using an sx lock.

While here, update comments on lock granularity.

MFC after: 2 weeks

Move setting of MNTK_MPSAFE flag before UFS1 extended attribute
auto-start so that the flag is set before we start performing I/O
in the auto-start routine.

MFC after: 2 weeks
Suggested by: kib

Don't auto-start or allow extattrctl for UFS2 file systems, as UFS2 has
native extended attributes. This didn't interfere with the operation of
UFS2 extended attributes, but the code shouldn't be running for UFS2.

MFC after: 2 weeks

Minor typo nit.

Axe the 'thread' argument from VOP_ISLOCKED() and lockstatus() as it is
always curthread.

As KPI gets broken by this patch, manpages and __FreeBSD_version will be
updated by further commits.

Tested by: Andrea Barberio <insomniac at slackware dot it>

Introduce some functions in the vnode locks namespace and in the ffs
namespace in order to handle lockmgr fields in a controlled way instead
than spreading all around bogus stubs:
- VN_LOCK_AREC() allows lock recursion for a specified vnode
- VN_LOCK_ASHARE() allows lock sharing for a specified vnode

In FFS land:
- BUF_AREC() allows lock recursion for a specified buffer lock
- BUF_NOREC() disallows recursion for a specified buffer lock

Side note: union_subr.c::unionfs_node_update() is the only other function
directly handling lockmgr fields. As this is not simple to fix, it has
been left behind as "sole" exception.

- Introduce lockmgr_args() in the lockmgr space. This function performs
the same operation of lockmgr() but accepting a custom wmesg, prio and
timo for the particular lock instance, overriding default values
lkp->lk_wmesg, lkp->lk_prio and lkp->lk_timo.
- Use lockmgr_args() in order to implement BUF_TIMELOCK()
- Cleanup BUF_LOCK()
- Remove LK_INTERNAL as it is nomore used in the lockmgr namespace

Tested by: Andrea Barberio <insomniac at slackware dot it>

Cleanup lockmgr interface and exported KPI:
- Remove the "thread" argument from the lockmgr() function as it is
always curthread now
- Axe lockcount() function as it is no longer used
- Axe LOCKMGR_ASSERT() as it is bogus really and no currently used.
Hopefully this will be soonly replaced by something suitable for it.
- Remove the prototype for dumplockinfo() as the function is no longer
present

Addictionally:
- Introduce a KASSERT() in lockstatus() in order to let it accept only
curthread or NULL as they should only be passed
- Do a little bit of style(9) cleanup on lockmgr.h

KPI results heavilly broken by this change, so manpages and
FreeBSD_version will be modified accordingly by further commits.

Tested by: matteo

- Introduce the function lockmgr_recursed() which returns true if the
lockmgr lkp, when held in exclusive mode, is recursed
- Introduce the function BUF_RECURSED() which does the same for bufobj
locks based on the top of lockmgr_recursed()
- Introduce the function BUF_ISLOCKED() which works like the counterpart
VOP_ISLOCKED(9), showing the state of lockmgr linked with the bufobj

BUF_RECURSED() and BUF_ISLOCKED() entirely replace the usage of bogus
BUF_REFCNT() in a more explicative and SMP-compliant way.
This allows us to axe out BUF_REFCNT() and leaving the function
lockcount() totally unused in our stock kernel. Further commits will
axe lockcount() as well as part of lockmgr() cleanup.

KPI results, obviously, broken so further commits will update manpages
and freebsd version.

Tested by: kris (on UFS and NFS)

VOP_LOCK1() (and so VOP_LOCK()) and VOP_UNLOCK() are only used in
conjuction with 'thread' argument passing which is always curthread.
Remove the unuseful extra-argument and pass explicitly curthread to lower
layer functions, when necessary.

KPI results broken by this change, which should affect several ports, so
version bumping and manpage update will be further committed.

Tested by: kris, pho, Diego Sardina <siarodx at gmail dot com>

vn_lock() is currently only used with the 'curthread' passed as argument.
Remove this argument and pass curthread directly to underlying
VOP_LOCK1() VFS method. This modify makes the code cleaner and in
particular remove an annoying dependence helping next lockmgr() cleanup.
KPI results, obviously, changed.

Manpage and FreeBSD_version will be updated through further commits.

As a side note, would be valuable to say that next commits will address
a similar cleanup about VFS methods, in particular vop_lock1 and
vop_unlock.

Tested by: Diego Sardina <siarodx at gmail dot com>,
Andrea Di Pasquale <whyx dot it at gmail dot com>

ffs_balloc_ufsX() routines, in the case of recovering from the failed
allocation, free the indirect blocks before clearing the disk pointers,
that could lead to the softupdate inconsistencies in the case of the
machine or disk crash at the wrong time.

Rearrange the recover code to do the ffs_blkfree() after the second
ffs_syncvnode(), that clears the pointers chain.

Proposed and reviewed by: tegge
Tested by: Peter Holm
MFC after: 3 weeks

style(9)

The ffs_balloc() routines, whan allocating the indirect blocks for
the inode, do the rollback in case the allocation failed (due to
insufficient free space or quota limits). But, the code does leaves the
buffers corresponding to the inoirect blocks on the vnode bufobj list.
This causes several assertion failures (for instance, "ffs_truncate3"
in ffs_truncate()) to fail, and could result in the indirect block
aliasing problem, like writing the context of such blocks to random
disk location.

Remove the buffers from the bufobj properly.

Reported and tested by: Peter Holm
Reviewed by: tegge
MFC after: 3 weeks

Fix a broken check that recently became more annoying because it now
gets enabled when INVARIANTS is on instead of DIAGNOSTIC (which apparently
nobody uses). From Tor's description:

This happens when the block range spans two block maps, the first in the
inode (mapping up to NDADDR direct blocks) and the second being the first
indirect block. The current check assumes that both block maps are
indirect blocks.

Work done by: tegge
Tested by: kris, kensmith

Fix build without INVARIANTS and update a comment to match
a change made in previous revision.

Turn most ffs 'DIAGNOSTIC's into INVARIANTS.

Merge first in a series of TrustedBSD MAC Framework KPI changes
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:

mac_<object>_<method/action>
mac_<object>_check_<method/action>

The previous naming scheme was inconsistent and mostly
reversed from the new scheme. Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier. Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods. Also simplify, slightly,
some entry point names.

All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.

Sponsored by: SPARTA (original patches against Mac OS X)
Obtained from: TrustedBSD Project, Apple Computer

Rename the kthread_xxx (e.g. kthread_create()) calls
to kproc_xxx as they actually make whole processes.
Thos makes way for us to add REAL kthread_create() and friends
that actually make theads. it turns out that most of these
calls actually end up being moved back to the thread version
when it's added. but we need to make this cosmetic change first.

I'd LOVE to do this rename in 7.0 so that we can eventually MFC the
new kthread_xxx() calls.

Get rid of qaddr_t.

Requested by: bde

Fix a DIV0 in case a large value for fs_avgfilesize or fs_avgfpdir
is given (with newfs or tunefs) and dirsize overflows.

In case dirsize is <= 0 because of an overflow set maxcontigdirs
to 0 so it will be 1 later. This is what would happen for large
fs_avgfilesize. [1]

Identified with help from: roberto, pjd
Submitted by: pjd [1]
Approved by: re (rwatson)
MFC after: 8 days

Perform range check before allocating memory when reading
extended attributes.

Reviewed by: kib
Approved by: re (hrs)
PR: 114389

Fix an annoying pointer/int cast warning that shows up on 64 bit systems.

Approved by: re

Fix livelock that could occur when snapshoting UFS with quotas, where
some quota limit was exceeded. Sequence of UFS_VALLOC()/UFS_VFREE()
call there could cause inodeblock to have both freefile and inodedep
dependencies without any inode in the block being marked for write.
Then, softdep_check_suspend() would return EAGAIN forewer.

Force write of inodeblock with allocated freefile softdependency by
setting IN_MODIFIED flag in softdep_freefile and unconditionally calling
UFS_UPDATE() in ufs_reclaim.

Reported by: kris
Debug help and tested by: Peter Holm
Approved by: re (kensmith)
MFC after: 3 weeks

Eliminate now-unused SUSER_ALLOWJAIL arguments to priv_check_cred(); in
some cases, move to priv_check() if it was an operation on a thread and
no other flags were present.

Eliminate caller-side jail exception checking (also now-unused); jail
privilege exception code now goes solely in kern_jail.c.

We can't yet eliminate suser() due to some cases in the KAME code where
a privilege check is performed and then used in many different deferred
paths. Do, however, move those prototypes to priv.h.

Reviewed by: csjp
Obtained from: TrustedBSD Project

Commit 14/14 of sched_lock decomposition.
- Use thread_lock() rather than sched_lock for per-thread scheduling
sychronization.
- Use the per-process spinlock rather than the sched_lock for per-process
scheduling synchronization.

Tested by: kris, current@
Tested on: i386, amd64, ULE, 4BSD, libthr, libkse, PREEMPTION, etc.
Discussed with: kris, attilio, kmacy, jhb, julian, bde (small parts each)

Change the VOP_OPEN(), vn_open() vnode operation and d_fdopen() cdev operation
argument from being file descriptor index into the pointer to struct file:
part 2. Convert calls missed in the first big commit.

Noted by: rwatson
Pointy hat to: kib

- 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)

Revert UF_OPENING workaround for CURRENT.
Change the VOP_OPEN(), vn_open() vnode operation and d_fdopen() cdev operation
argument from being file descriptor index into the pointer to struct file.

Proposed and reviewed by: jhb
Reviewed by: daichi (unionfs)
Approved by: re (kensmith)

- Remove unnecessary vnode internal locking - v_vflag is protect by vnode's
lock (not vnode's interlock).
- Simplify code a bit.

Eliminate VI_LOCK()/VI_UNLOCK() pair from getattr and close code paths.
It's hard to measure performance improvement on my test machine, but the
change won't degrade performance for sure. I can measure slight improvement
for debugging kernel and it can also be a win for machines where atomic
operation is more expensive.

Reviewed by: kib

Since renaming of vop_lock to _vop_lock, pre- and post-condition
function calls are no more generated for vop_lock.
Rename _vop_lock to vop_lock1 to satisfy tools/vnode_if.awk assumption
about vop naming conventions. This restores pre/post-condition calls.

Add a newline to the printf message.

Fix the NAMEI zone leak when snapshot was successfully created.

Reported and tested by: Peter Holm
MFC after: 2 weeks

Recalculate the NEWBLOCK flag for pagedep structure after the softdep
lock is dropped, since pagedep may be already processed and deallocated.

Found and tested by: kris
MFC after: 2 weeks

When LK_NOWAIT is passed as argument to process_worklist_item(), this
does not prevent handle_workitem_remove() from recursing into a blocking
version. Add the dirrem to worklist instead of processing it now if this
is the case.

Reported and tested by: kris
Submitted by: tegge
MFC after: 2 weeks

Use *_EMPTY macros when appropriate.

Revert rev. 1.205. Replace unconditional acquision of Giant when QUOTAS are
defined with VFS_LOCK_GIANT(NULL) call.
This shall fix softdep operation when mpsafe_vfs = 0.

Reported and tested by: kris
Submitted by: tegge
MFC after: 1 week

Mark UFS as being MP-Safe in "options QUOTA" case too. Remove no more
neccessary Giant acquisions in softdepend processing code.

Tested by: Peter Holm
Reviewed by: tegge
Approved by: re (kensmith)

When we write extended attributes, assert that the inode hasn't
already been deleted. The assertion is important to show that
we won't end up accounting for extended attribute blocks (using
fs_pendingblocks) in our subsequent call to fs_alloc().

Agreed verbally by: mckusick

MFC after: 3 weeks

Implement fine-grained locking for UFS quotas.

Each struct dquot gets dq_lock mutex to protect dq_flags and to interlock
with DQ_LOCK. qhash, dqfreelist and dq.dq_cnt are protected by global
dqhlock mutex.

i_dquot array for inode is protected by lockmgr' vnode lock, corresponding
assert added to the dqget(). Access to struct ufsmount quota-related fields
(um_quotas and um_qflags) is protected by um_lock.

Tested by: Peter Holm
Reviewed by: tegge
Approved by: re (kensmith)

This work were not possible without enormous amount of help given by
Tor Egge and Peter Holm. Tor reviewed each version of patch, pointed out
numerous errors and provided invaluable suggestions. Peter did tireless
testing of the patch as it was developed.

Call getinoquota() before allocating new block for the directory to properly
account for block allocation.

Tested by: Peter Holm
Reviewed by: tegge
Approved by: re (kensmith)

Remove unneeded getinoquota() call in the ufs_access().

Tested by: Peter Holm
Reviewed by: tegge
Approved by: re (kensmith)

Make insmntque() externally visibile and allow it to fail (e.g. during
late stages of unmount). On failure, the vnode is recycled.

Add insmntque1(), to allow for file system specific cleanup when
recycling vnode on failure.

Change getnewvnode() to no longer call insmntque(). Previously,
embryonic vnodes were put onto the list of vnode belonging to a file
system, which is unsafe for a file system marked MPSAFE.

Change vfs_hash_insert() to no longer lock the vnode. The caller now
has that responsibility.

Change most file systems to lock the vnode and call insmntque() or
insmntque1() after a new vnode has been sufficiently setup. Handle
failed insmntque*() calls by propagating errors to callers, possibly
after some file system specific cleanup.

Approved by: re (kensmith)
Reviewed by: kib
In collaboration with: kib

Move macros describing extended attributes in UFS from
<sys/extattr.h> to <ufs/ufs/extattr.h>. Move description
of extended attributes in UFS from man9/extattr.9 to
man5/fs.5.

Note that restore will not compile until <sys/extattr.h>
and <ufs/ufs/extattr.h> have been updated.

Suggested by: Robert Watson

Fix build breakage.

Change:
"... try to use VADMIN in preference to VADMIN ..."
To:
"... try to use VADMIN in preference to VWRITE ..."

Rename PRIV_VFS_CLEARSUGID to PRIV_VFS_RETAINSUGID, which seems to better
describe the privilege.

OK'ed by: rwatson

Avoid checking for privileges if there is no need to.

Discussed with: rwatson

Account for di_blocks allocations when IN_SPACECOUNTED is set in an
inode's i_flag.

It's possible that after ufs_infactive() calls softdep_releasefile(),
i_nlink stays >0 for a considerable amount of time (> 60 seconds here).
During this period, any ffs allocation routines that alter di_blocks
must also account for the blocks in the filesystem's fs_pendingblocks
value.

This change fixes an eventual df/du discrepency that will happen as
the result of fs_pendingblocks being reduced to <0.

The only manifestation of this that people may recognise is the
following message on boot:

/somefs: update error: blocks -N files M

at which point the negative pending block count is adjusted to zero.

Reviewed by: tegge
MFC after: 3 weeks

The functions that set and delete external attributes must check
that the filesystem is not mounted read-only before proceeding.

Reported by: Ryan Beasley <ryanb@FreeBSD.org>
MFC after: 1 week

Rename three quota privileges from the UFS privilege namespace to the
VFS privilege namespace: exceedquota, getquota, and setquota. Leave
UFS-specific quota configuration privileges in the UFS name space.

This renumbers VFS and UFS privileges, so requires rebuilding modules
if you are using security policies aware of privilege identifiers.
This is likely no one at this point since none of the committed MAC
policies use the privilege checks.

Limit quota privileges in jail to PRIV_UFS_GETQUOTA and
PRIV_UFS_SETQUOTA.

This README file is obsolete. The cited problems were fixed long ago
and the code is installed by default so no longer requires action by
the administrator to be included.

Move vnode-to-file-handle translation from vfs_vptofh to vop_vptofh method.
This way we may support multiple structures in v_data vnode field within
one file system without using black magic.

Vnode-to-file-handle should be VOP in the first place, but was made VFS
operation to keep interface as compatible as possible with SUN's VFS.
BTW. Now Solaris also implements vnode-to-file-handle as VOP operation.

VFS_VPTOFH() was left for API backward compatibility, but is marked for
removal before 8.0-RELEASE.

Approved by: mckusick
Discussed with: many (on IRC)
Tested with: ufs, msdosfs, cd9660, nullfs and zfs

Style(9).

Remove not needed acquision of the mount interlock aroung reading of
mnt_kern_flags in ufs_itimes().

Suggested by: ssouhlal
Confirmed by: tegge
MFC after: 2 weeks

Call pbgetvp() and pbrelvp() instead of setting b_vp directly.

PR: kern/108151

If quotacheck or edquota reset the block or inode grace time for
a user or group, when the kernel first sees this, it will update
the grace time value. However, it never flags the quota as modified
and the updated value never makes it to the quota data file unless
the user actually makes some other change that would write the
data out.

Fixed to flag the quota as modified if the soft limit has actually
been reached and should be now enforced.

Prevent quotactl calls that pass in an id of -1 from incorrectly
using the callers UID instead of the GID when performing group
operations. This could allow users to determine group quota
information for groups they are not a member of in some cases.

Rename the "uid" parameter in ufs_quotactl to "id" to better show
that it is used for more than just the uid, and to be more in line
with the naming conventions in the other quota routines.

PR: kern/33940