Use the reserved space in struct xfs_dqblk to store a UUID and a crc
for the quota blocks.

[dchinner@redhat.com] Add a LSN field and update for current verifier
infrastructure.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Enable tracking of high and low watermarks for preallocation
throttling of files under quota restrictions. These values are
calculated when the quota limit is read from disk or modified and
cached for later use by the throttling algorithm.

The high watermark specifies when preallocation is disabled, the
low watermark specifies when throttling is enabled and the low free
space data structure contains precalculated low free space limits
to serve as input to determine the level of throttling required.

Note that the low free space data structure is based on the
existing global low free space data structure with the exception of
using three stages (5%, 3% and 1%) rather than five to reduce the
impact of xfs_dquot memory overhead.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Modify xfs_qm_adjust_dqlimits() to take the xfs_dquot as a
parameter instead of just the xfs_disk_dquot_t so we can update
in-memory fields if necessary.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

The disk quota allocation log space reservation is calcuated at runtime,
this patch does it at mount time.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
CC: Dave Chinner <david@fromorbit.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

To separate the verifiers from iodone functions and associate read
and write verifiers at the same time, introduce a buffer verifier
operations structure to the xfs_buf.

This avoids the need for assigning the write verifier, clearing the
iodone function and re-running ioend processing in the read
verifier, and gets rid of the nasty "b_pre_io" name for the write
verifier function pointer. If we ever need to, it will also be
easier to add further content specific callbacks to a buffer with an
ops structure in place.

We also avoid needing to export verifier functions, instead we
can simply export the ops structures for those that are needed
outside the function they are defined in.

This patch also fixes a directory block readahead verifier issue
it exposed.

This patch also adds ops callbacks to the inode/alloc btree blocks
initialised by growfs. These will need more work before they will
work with CRCs.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NPhil White <pwhite@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Metadata buffers that are read from disk have write verifiers
already attached to them, but newly allocated buffers do not. Add
appropriate write verifiers to all new metadata buffers.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

These verifiers are essentially the same code as the read verifiers,
but do not require ioend processing. Hence factor the read verifier
functions and add a new write verifier wrapper that is used as the
callback.

This is done as one large patch for all verifiers rather than one
patch per verifier as the change is largely mechanical. This
includes hooking up the write verifier via the read verifier
function.

Hooking up the write verifier for buffers obtained via
xfs_trans_get_buf() will be done in a separate patch as that touches
code in many different places rather than just the verifier
functions.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Add a dquot buffer verify callback function and pass it into the
buffer read functions. This checks all the dquots in a buffer, but
cannot completely verify the dquot ids are correct. Also, errors
cannot be repaired, so an additional function is added to repair bad
dquots in the buffer if such an error is detected in a context where
repair is allowed.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NPhil White <pwhite@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Add a verifier function callback capability to the buffer read
interfaces.  This will be used by the callers to supply a function
that verifies the contents of the buffer when it is read from disk.
This patch does not provide callback functions, but simply modifies
the interfaces to allow them to be called.

The reason for adding this to the read interfaces is that it is very
difficult to tell fom the outside is a buffer was just read from
disk or whether we just pulled it out of cache. Supplying a callbck
allows the buffer cache to use it's internal knowledge of the buffer
to execute it only when the buffer is read from disk.

It is intended that the verifier functions will mark the buffer with
an EFSCORRUPTED error when verification fails. This allows the
reading context to distinguish a verification error from an IO
error, and potentially take further actions on the buffer (e.g.
attempt repair) based on the error reported.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NPhil White <pwhite@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Untangle the header file includes a bit by moving the definition of
xfs_agino_t to xfs_types.h. This removes the dependency that xfs_ag.h has on
xfs_inum.h, meaning we don't need to include xfs_inum.h everywhere we include
xfs_ag.h.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

xfs_trans_ail_delete_bulk() can be called from different contexts so
if the item is not in the AIL we need different shutdown for each
context.  Pass in the shutdown method needed so the correct action
can be taken.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Queue delwri buffers on a local on-stack list instead of a per-buftarg one,
and write back the buffers per-process instead of by waking up xfsbufd.

This is now easily doable given that we have very few places left that write
delwri buffers:

 - log recovery:
	Only done at mount time, and already forcing out the buffers
	synchronously using xfs_flush_buftarg

 - quotacheck:
	Same story.

 - dquot reclaim:
	Writes out dirty dquots on the LRU under memory pressure.  We might
	want to look into doing more of this via xfsaild, but it's already
	more optimal than the synchronous inode reclaim that writes each
	buffer synchronously.

 - xfsaild:
	This is the main beneficiary of the change.  By keeping a local list
	of buffers to write we reduce latency of writing out buffers, and
	more importably we can remove all the delwri list promotions which
	were hitting the buffer cache hard under sustained metadata loads.

The implementation is very straight forward - xfs_buf_delwri_queue now gets
a new list_head pointer that it adds the delwri buffers to, and all callers
need to eventually submit the list using xfs_buf_delwi_submit or
xfs_buf_delwi_submit_nowait.  Buffers that already are on a delwri list are
skipped in xfs_buf_delwri_queue, assuming they already are on another delwri
list.  The biggest change to pass down the buffer list was done to the AIL
pushing. Now that we operate on buffers the trylock, push and pushbuf log
item methods are merged into a single push routine, which tries to lock the
item, and if possible add the buffer that needs writeback to the buffer list.
This leads to much simpler code than the previous split but requires the
individual IOP_PUSH instances to unlock and reacquire the AIL around calls
to blocking routines.

Given that xfsailds now also handle writing out buffers, the conditions for
log forcing and the sleep times needed some small changes.  The most
important one is that we consider an AIL busy as long we still have buffers
to push, and the other one is that we do increment the pushed LSN for
buffers that are under flushing at this moment, but still count them towards
the stuck items for restart purposes.  Without this we could hammer on stuck
items without ever forcing the log and not make progress under heavy random
delete workloads on fast flash storage devices.

[ Dave Chinner:
	- rebase on previous patches.
	- improved comments for XBF_DELWRI_Q handling
	- fix XBF_ASYNC handling in queue submission (test 106 failure)
	- rename delwri submit function buffer list parameters for clarity
	- xfs_efd_item_push() should return XFS_ITEM_PINNED ]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Instead of writing the buffer directly from inside xfs_qm_dqflush return it
to the caller and let the caller decide what to do with the buffer.  Also
remove the pincount check in xfs_qm_dqflush that all non-blocking callers
already implement and the now unused flags parameter and the XFS_DQ_IS_DIRTY
check that all callers already perform.

[ Dave Chinner: fixed build error cause by missing '{'. ]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

If a filesystem has been forced shutdown we are never going to write inodes
to disk, which means the inode items will stay in the AIL until we free
the inode. Currently that is not a problem, but a pending change requires us
to empty the AIL before shutting down the filesystem. In that case leaving
the inode in the AIL is lethal. Make sure to remove the log item from the AIL
to allow emptying the AIL on shutdown filesystems.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

If a filesystem has been forced shutdown we are never going to write dquots
to disk, which means the dquot items will stay in the AIL forever.
Currently that is not a problem, but a pending chance requires us to
empty the AIL before shutting down the filesystem, in which case this
behaviour is lethal.  Make sure to remove the log item from the AIL
to allow emptying the AIL on shutdown filesystems.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

xfs_qm_exit() is called in init_xfs_fs().
Signed-off-by: NGerard Snitselaar <dev@snitselaar.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

If we initialize the slab caches for the quota code when XFS is loaded there
is no need for a global and reference counted quota manager structure.  Drop
all this overhead and also fix the error handling during quota initialization.
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

Instead of keeping a separate per-filesystem list of dquots we can walk
the radix tree for the two places where we need to iterate all quota
structures.
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

Replace the global hash tables for looking up in-memory dquot structures
with per-filesystem radix trees to allow scaling to a large number of
in-memory dquot structures.
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

Replace the global dquot lru lists with a per-filesystem one.

Note that the shrinker isn't wire up to the per-superblock VFS shrinker
infrastructure as would have problems summing up and splitting the counts
for inodes and dquots.  I don't think this is a major problem as the quota
cache isn't as interwinded with the inode cache as the dentry cache is,
because an inode that is dropped from the cache will generally release
a dquot reference, but most of the time it won't be the last one.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Switch the quota code over to use the generic XFS statistics infrastructure.
While the legacy /proc/fs/xfs/xqm and /proc/fs/xfs/xqmstats interfaces are
preserved for now the statistics that still have a meaning with the current
code are now also available from /proc/fs/xfs/stats.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

There is no reason to wake up log space waiters when unlocking inodes or
dquots, and the commit log has no explanation for this function either.

Given that we now have exact log space wakeups everywhere we can assume
the reason for this function was to paper over log space races in earlier
XFS versions.
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

In general, quota allows us to use disk blocks and inodes up to each
limit, that is, they are available if they don't exceed their limitations.
Current xfs sets their available ranges to lower than them except disk
inode quota check. So, this patch changes the ranges to not beyond them.
Signed-off-by: NMitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
Cc: Ben Myers <bpm@sgi.com>
Cc: Alex Elder <elder@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit 20f12d8a)

In general, quota allows us to use disk blocks and inodes up to each
limit, that is, they are available if they don't exceed their limitations.
Current xfs sets their available ranges to lower than them except disk
inode quota check. So, this patch changes the ranges to not beyond them.
Signed-off-by: NMitsuo Hayasaka <mitsuo.hayasaka.hu@hitachi.com>
Cc: Ben Myers <bpm@sgi.com>
Cc: Alex Elder <elder@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Stop reusing dquots from the freelist when allocating new ones directly, and
implement a shrinker that actually follows the specifications for the
interface.  The shrinker implementation is still highly suboptimal at this
point, but we can gradually work on it.

This also fixes an bug in the previous lock ordering, where we would take
the hash and dqlist locks inside of the freelist lock against the normal
lock ordering.  This is only solvable by introducing the dispose list,
and thus not when using direct reclaim of unused dquots for new allocations.

As a side-effect the quota upper bound and used to free ratio values in
/proc/fs/xfs/xqm are set to 0 as these values don't make any sense in the
new world order.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit 04da0c81)

Stop reusing dquots from the freelist when allocating new ones directly, and
implement a shrinker that actually follows the specifications for the
interface.  The shrinker implementation is still highly suboptimal at this
point, but we can gradually work on it.

This also fixes an bug in the previous lock ordering, where we would take
the hash and dqlist locks inside of the freelist lock against the normal
lock ordering.  This is only solvable by introducing the dispose list,
and thus not when using direct reclaim of unused dquots for new allocations.

As a side-effect the quota upper bound and used to free ratio values in
/proc/fs/xfs/xqm are set to 0 as these values don't make any sense in the
new world order.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

Define a new function xfs_inode_dquot() that takes a inode pointer
and a disk quota type and returns the quota pointer for the specified
quota type.

This simplifies the xfs_qm_dqget() error path significantly.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

Create a new function xfs_this_quota_on() that takes a xfs_mount
data structure and a disk quota type and returns true if the specified
type of quota is ON in the xfs_mount data structure.
Signed-off-by: NChandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

Just read the id 0 dquot from disk directly in xfs_qm_init_quotainfo instead
of going through dqget and requiring a special flag to not add the dquot to
any lists.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

This function doesn't help the code flow, so merge the dquot allocation and
transaction handling into xfs_qm_dqread.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Factor the common pattern of:

	xfs_dqlock(dqp);
	XFS_DQHOLD(dqp);
	xfs_dqunlock(dqp);

into a new helper, and remove XFS_DQHOLD now that only one other caller
is left.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Allow xfs_qm_dqput to work without trylock loops by nesting the freelist lock
inside the dquot qlock.  In turn that requires trylocks in the reclaim path
instead, but given it's a classic tradeoff between fast and slow path, and
we follow the model of the inode and dentry caches.

Document our new lock order now that it has settled.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Introduce a new XFS_DQ_FREEING flag that tells lookup and mplist walks
to skip a dquot that is beeing freed, and use this avoid the trylock
on the hash and mplist locks in xfs_qm_dqreclaim_one.  Also simplify
xfs_dqpurge by moving the inodes to a dispose list after marking them
XFS_DQ_FREEING and avoid the locker ordering constraints.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Do not remove dquots from the freelist when we grab a reference to them in
xfs_qm_dqlookup, but leave them on the freelist util scanning notices that
they have a reference.  This speeds up the lookup fastpath, and greatly
simplifies the lock ordering constraints.  Note that the same scheme is
used by the VFS inode and dentry caches.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Free dquots when purging them during umount instead of keeping them around
on the freelist in a degraded state.  The out of order locking in
xfs_qm_dqpurge will be removed again later in this series.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Rearrange the code to avoid the conditional locking around the flist_locked
variable.  This means we lose a (rather pointless) assert, and hold the
freelist lock a bit longer for one corner case.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Mark the trivial lock wrappers as inline, and make the naming consistent
for all of them.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Only skip pinned dquots if SYNC_TRYLOCK is specified, and adjust the callers
to keep the behaviour unchanged.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>