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

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

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 t

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

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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 init

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

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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

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)

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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

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

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- 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 i

- 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

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- 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.

Sponsore

- 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

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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
modificati

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)

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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 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

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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 act

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

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- 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 in

- 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.

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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 lock

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

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Do not translate the IN_ACCESS inode flag into the IN_MODIFIED while filesystem
is suspending/suspended. Doing so may result in deadlock. Instead, set the
(new) IN_LAZYACCESS flag, that becomes IN_MO

Do not translate the IN_ACCESS inode flag into the IN_MODIFIED while filesystem
is suspending/suspended. Doing so may result in deadlock. Instead, set the
(new) IN_LAZYACCESS flag, that becomes IN_MODIFIED when suspend is lifted.

Change the locking protocol in order to set the IN_ACCESS and timestamps
without upgrading shared vnode lock to exclusive (see comments in the
inode.h). Before that, inode was modified while holding only shared
lock.

Tested by: Peter Holm
Reviewed by: tegge, bde
Approved by: pjd (mentor)
MFC after: 3 weeks

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Add mnt_noasync counter to better handle interleaved calls to nmount(),
sync() and sync_fsync() without losing MNT_ASYNC. Add MNTK_ASYNC flag
which is set only when MNT_ASYNC is set and mnt_noasync

Add mnt_noasync counter to better handle interleaved calls to nmount(),
sync() and sync_fsync() without losing MNT_ASYNC. Add MNTK_ASYNC flag
which is set only when MNT_ASYNC is set and mnt_noasync is zero, and
check that flag instead of MNT_ASYNC before initiating async io.

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Use vfs_hash instead of home-rolled.

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

Move UFS from DEVFS backing to GEOM backing.

This eliminates a bunch of vnode overhead (approx 1-2 % speed
improvement) and gives us more control over the access to the storage
device.

Access count

Move UFS from DEVFS backing to GEOM backing.

This eliminates a bunch of vnode overhead (approx 1-2 % speed
improvement) and gives us more control over the access to the storage
device.

Access counts on the underlying device are not correctly tracked and
therefore it is possible to read-only mount the same disk device multiple
times:
syv# mount -p
/dev/md0 /var ufs rw 2 2
/dev/ad0 /mnt ufs ro 1 1
/dev/ad0 /mnt2 ufs ro 1 1
/dev/ad0 /mnt3 ufs ro 1 1

Since UFS/FFS is not a synchrousely consistent filesystem (ie: it caches
things in RAM) this is not possible with read-write mounts, and the system
will correctly reject this.

Details:

Add a geom consumer and a bufobj pointer to ufsmount.

Eliminate the vnode argument from softdep_disk_prewrite().
Pick the vnode out of bp->b_vp for now. Eventually we
should find it through bp->b_bufobj->b_private.

In the mountcode, use g_vfs_open() once we have used
VOP_ACCESS() to check permissions.

When upgrading and downgrading between r/o and r/w do the
right thing with GEOM access counts. Remove all the
workarounds for not being able to do this with VOP_OPEN().

If we are the root mount, drop the exclusive access count
until we upgrade to r/w. This allows fsck of the root
filesystem and the MNT_RELOAD to work correctly.

Set bo_private to the GEOM consumer on the device bufobj.

Change the ffs_ops->strategy function to call g_vfs_strategy()

In ufs_strategy() directly call the strategy on the disk
bufobj. Same in rawread.

In ffs_fsync() we will no longer see VCHR device nodes, so
remove code which synced the filesystem mounted on it, in
case we came there. I'm not sure this code made sense in
the first place since we would have taken the specfs route
on such a vnode.

Redo the highly bogus readblock() function in the snapshot
code to something slightly less bogus: Constructing an uio
and using physio was really quite a detour. Instead just
fill in a bio and ship it down.

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Avoid using casts as lvalues. Introduce DIP_SET macro which sets proper
inode field based on UFS version. Use DIP ro read values and DIP_SET
to modify them throughout FFS code base.

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

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

Approved by: core, rwatson

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Eliminate the i_devvp field from the incore UFS inodes, we can
get the same value from ip->i_ump->um_devvp.

This saves a pointer in the memory copies of inodes, which can
easily run into several hun

Eliminate the i_devvp field from the incore UFS inodes, we can
get the same value from ip->i_ump->um_devvp.

This saves a pointer in the memory copies of inodes, which can
easily run into several hundred kilobytes.

The extra indirection is unmeasurable in benchmarks.

Approved by: mckusick

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Update to previous change (1.54) to use an approperly wide inode field
so as to work correctly on 64-bit platforms.

Reported-by: Jake Burkholder <jake@locore.ca>
Sponsored by: DARPA & NAI Labs.
Ap

Update to previous change (1.54) to use an approperly wide inode field
so as to work correctly on 64-bit platforms.

Reported-by: Jake Burkholder <jake@locore.ca>
Sponsored by: DARPA & NAI Labs.
Approved by: Ian Dowse <iedowse@maths.tcd.ie>

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Only the most recent snapshot contains the complete list of blocks
that were copied in all of the earlier snapshots, thus its precomputed
list must be used in the copyonwrite test. Using incomplete l

Only the most recent snapshot contains the complete list of blocks
that were copied in all of the earlier snapshots, thus its precomputed
list must be used in the copyonwrite test. Using incomplete lists may
lead to deadlock. Also do not include the blocks used for the indirect
pointers in the indirect pointers as this may lead to inconsistent
snapshots.

Sponsored by: DARPA & NAI Labs.
Approved by: re

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When creating a snapshot, create a list of initially allocated blocks.
Whenever doing a copy-on-write check, first look in the list of
initially allocated blocks to see if it is there. If so, no furt

When creating a snapshot, create a list of initially allocated blocks.
Whenever doing a copy-on-write check, first look in the list of
initially allocated blocks to see if it is there. If so, no further
check is needed. If not, fall through and do the full check. This
change eliminates one of two known deadlocks caused by snapshots.
Handling the second deadlock will be the subject of another check-in.
This change also reduces the cost of the copy-on-write check by
speeding up the verification of frequently checked blocks.

Sponsored by: DARPA & NAI Labs.

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Make it a tad easier to deal with struct inode in userland programs which
fondle /dev/kmem by using "struct cdev *" instead of "dev_t".

Requsted by: jake