write_cache_pages() uses i_mapping->writeback_index to pick up where it
left off the last time a given inode was found by pdflush or
balance_dirty_pages (or anyone else who sets wbc->range_cyclic)

alloc_inode() should set it to a sane value so that writeback doesn't
start in the middle of a file.  It is somewhat difficult to notice the bug
since write_cache_pages will loop around to the start of the file and the
elevator helps hide the resulting seeks.

For whatever reason, Btrfs hits this often.  Unpatched, untarring 30
copies of the linux kernel in series runs at 47MB/s on a single sata
drive.  With this fix, it jumps to 62MB/s.
Signed-off-by: NChris Mason <chris.mason@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The patches that are intended to introduce copy-on-write credentials for 2.6.28
require abstraction of access to some fields of the task structure,
particularly for the case of one task accessing another's credentials where RCU
will have to be observed.

Introduced here are trivial no-op versions of the desired accessors for current
and other tasks so that other subsystems can start to be converted over more
easily.

Wrappers are introduced into a new header (linux/cred.h) for UID/GID,
EUID/EGID, SUID/SGID, FSUID/FSGID, cap_effective and current's subscribed
user_struct.  These wrappers are macros because the ordering between header
files mitigates against making them inline functions.

linux/cred.h is #included from linux/sched.h.

Further, XFS is modified such that it no longer defines and uses parameterised
versions of current_fs[ug]id(), thus getting rid of the namespace collision
otherwise incurred.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Add a dlm_ prefix to the struct names in config.c.  This resolves a
conflict with struct node in particular, when include/linux/node.h
happens to be included.
Reported-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Teigland <teigland@redhat.com>

A couple of unlikely error conditions were missing a kfree on the error
exit path.
Reported-by: NJuha Leppanen <juha_motorsportcom@luukku.com>
Signed-off-by: NDavid Teigland <teigland@redhat.com>

The ticket allocation code got reworked in 2.6.26 and we now free tickets
whereas before we used to cache them so the use-after-free went
undetected.

SGI-PV: 985525

SGI-Modid: xfs-linux-melb:xfs-kern:31877a
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NDavid Chinner <david@fromorbit.com>

xfs_bmap_count_leaves and xfs_bmap_disk_count_leaves always return always
0, make them void.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31844a
Signed-off-by: NRuben Porras <ruben.porras@linworks.de>
Signed-off-by: NDonald Douwsma <donaldd@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Use KM_NOFS to prevent recursion back into the filesystem which can cause
deadlocks.

In the case of xfs_iread() we hold the lock on the inode cluster buffer
while allocating memory for the trace buffers. If we recurse back into XFS
to flush data that may require a transaction to allocate extents which
needs log space. This can deadlock with the xfsaild thread which can't
push the tail of the log because it is trying to get the inode cluster
buffer lock.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31838a
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NDavid Chinner <david@fromorbit.com>

Use KM_MAYFAIL for the m_perag allocation, we can deal with the error
easily and blocking forever during mount is not a good idea either.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31837a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

xfs_mount_free mostly frees the perag data, which is something that is
duplicated in the mount error path.

Move the XFS_QM_DONE call to the caller and remove the useless
mutex_destroy/spinlock_destroy calls so that we can re-use it for the
mount error path. Also rename it to xfs_free_perag to reflect what it
does.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31836a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

xfs_readsb is called before xfs_mount so xfs_freesb should be called after
xfs_unmountfs, too. This means it now happens after a few things during
the of xfs_unmount which all have nothing to do with the superblock.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31835a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

xfs_unmounts can't and shouldn't return errors so declare it as returning
void.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31833a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Remove all the useless flags and code keyed off it in xfs_mountfs.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31831a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

The root inode is allocated in xfs_mountfs so it should be release in
xfs_unmountfs. For the unmount case that means we do it after the the
xfs_sync(mp, SYNC_WAIT | SYNC_CLOSE) in the forced shutdown case and the
dmapi unmount event. Note that both reference the rip variable which might
be freed by that time in case inode flushing has kicked in, so strictly
speaking this might count as a bug fix

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31830a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

xfs_ichtime updates the xfs_inode and Linux inode timestamps just fine, no
need to call file_update_time and then copy the values over to the XFS
inode. The only additional thing in file_update_time are checks not
applicable to the write path.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31829a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NDavid Chinner <david@fromorbit.com>

Port a little optmization from file_update_time to xfs_ichgtime, and only
update the timestamp and mark the inode dirty if the timestamp actually
changes in the timer tick resultion supported by the running kernel.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31827a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

In xfs_ialloc we just want to set all timestamps to the current time. We
don't need to mark the inode dirty like xfs_ichgtime does, and we don't
need nor want the opimizations in xfs_ichgtime that I will introduce in
the next patch.

So just opencode the timestamp update in xfs_ialloc, and remove the new
unused XFS_ICHGTIME_ACC case in xfs_ichgtime.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31825a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Now that all users of the sema_t are gone from XFS we can finally kill it.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31823a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Use the new completion flush code to implement the dquot flush lock.
Removes one of the final users of semaphores in the XFS code base.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31822a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Use the new completion flush code to implement the inode flush lock.
Removes one of the final users of semaphores in the XFS code base.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31817a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

The xfs_buf_t b_iodonesema is really just a semaphore that wants to be a
completion. Change it to a completion and remove the last user of the
sema_t from XFS.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31815a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

A lot of code has been converted away from semaphores, but there are still
comments that reference semaphore behaviour. The log code is the worst
offender. Update the comments to reflect what the code really does now.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31814a
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31813a
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

SGI-PV: 957103

SGI-Modid: xfs-linux-melb:xfs-kern:31804a
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

The alloc and inobt btree use the same agbp/agno pair in the btree_cur
union. Make them use the same bc_private.a union member so that code for
these two short form btree implementations can be shared.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31788a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NTim Shimmin <tes@sgi.com>
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Remove unneeded xfs_btree_get_block forward declaration. Move
xfs_btree_firstrec next to xfs_btree_lastrec.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31787a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NTim Shimmin <tes@sgi.com>
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Sanitize setting up the Linux indode.

Setting up the xfs_inode <-> inode link is opencoded in xfs_iget_core now
because that's the only place it needs to be done, xfs_initialize_vnode is
renamed to xfs_setup_inode and loses all superflous paramaters. The check
for I_NEW is removed because it always is true and the di_mode check moves
into xfs_iget_core because it's only needed there.

xfs_set_inodeops and xfs_revalidate_inode are merged into xfs_setup_inode
and the whole things is moved into xfs_iops.c where it belongs.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31782a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

All remaining bhv_vnode_t instance are in code that's more or less Linux
specific. (Well, for xfs_acl.c that could be argued, but that code is on
the removal list, too). So just do an s/bhv_vnode_t/struct inode/ over the
whole tree. We can clean up variable naming and some useless helpers
later.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31781a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

In various places we can just move a VFS_I call into the argument list of
called functions/macros instead of having a local bhv_vnode_t.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31776a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

When multiple inodes are locked in XFS it happens in order of the inode
number, with the everything but the first inode trylocked if any of the
previous inodes is in the AIL.

Except for the sorting of the inodes this logic is implemented in
xfs_lock_inodes, but also partially duplicated in xfs_lock_dir_and_entry
in a particularly stupid way adds a lock roundtrip if the inode ordering
is not optimal.

This patch adds a new helper xfs_lock_two_inodes that takes two inodes and
locks them in the most optimal way according to the above locking protocol
and uses it for all places that want to lock two inodes.

The only caller of xfs_lock_inodes is xfs_rename which might lock up to
four inodes.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31772a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDonald Douwsma <donaldd@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

All the error injection is already enabled through ifdef DEBUG, so kill
the never set second cpp symbol to activate it without the rest of the
debugging infrastructure.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31771a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Now that all direct calls to VN_HOLD/VN_RELE are gone we can implement
IHOLD/IRELE directly.

For the IHOLD case also replace igrab with a direct increment of i_count
because we are guaranteed to already have a live and referenced inode by
the VFS. Also remove the vn_hold statistic because it's been rather
meaningless for some time with most references done by other callers.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31764a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Use IHOLD(ip) instead of VN_HOLD(VFS_I(ip)).

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31765a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

All the ACL routines are called from inode operations which are guaranteed
to have a referenced inode by the VFS, so there's no need for the ACL code
to grab another temporary one.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31763a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

bhv_vnode_t is just a typedef for struct inode, so there's
no need for a helper to convert between the two.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31761a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

bhv_vnode_t is just a typedef for struct inode, so there's
no need for a helper to convert between the two.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31760a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31758a
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Looks like somehow xfs got missed in the conversion that took place in
e231c2ee, "Convert ERR_PTR(PTR_ERR(p))
instances to ERR_CAST(p)
<http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit
diff;h=e231c2ee>"

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31757a
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Thanks to hch's endian work, INT_GET etc are no longer used, and may as
well be removed. INT_SET is still used in the acl code, though.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31756a
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Move it from the attr code to the transaction code and make
the attr code call the new function.

We rolltrans is really usefull whenever we want to use rolling
transaction, should be generic, it isn't dependent on any part
of the attr code anyway.

We use this excuse to change all the:

if ((error = xfs_attr_rolltrans()))

calls into:

error = xfs_trans_roll();

if (error)

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31729a
Signed-off-by: NNiv Sardi <xaiki@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Add a helper to free the m_fsname/m_rtname/m_logname allocations and use
it properly for all mount failure cases. Also switch the allocations for
these to kstrdup while we're at it.

SGI-PV: 981498

SGI-Modid: xfs-linux-melb:xfs-kern:31728a
Signed-off-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>
Signed-off-by: NDavid Chinner <david@fromorbit.com>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>