Commit graph

188 commits

Author SHA1 Message Date
Christoph Hellwig
1d5ae5dfee xfs: cleanup I/O-related buffer flags
Remove the unused and misnamed _XBF_RUN_QUEUES flag, rename XBF_LOG_BUFFER
to the more fitting XBF_SYNCIO, and split XBF_ORDERED into XBF_FUA and
XBF_FLUSH to allow more fine grained control over the bio flags.  Also
cleanup processing of the flags in _xfs_buf_ioapply to make more sense,
and renumber the sparse flag number space to group flags by purpose.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2011-07-08 14:36:32 +02:00
Christoph Hellwig
c8da0faf6b xfs: return the buffer locked from xfs_buf_get_uncached
All other xfs_buf_get/read-like helpers return the buffer locked, make sure
xfs_buf_get_uncached isn't different for no reason.  Half of the callers
already lock it directly after, and the others probably should also keep
it locked if only for consistency and beeing able to use xfs_buf_rele,
but I'll leave that for later.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2011-07-08 14:36:25 +02:00
Christoph Hellwig
0c842ad46a xfs: clean up buffer locking helpers
Rename xfs_buf_cond_lock and reverse it's return value to fit most other
trylock operations in the Kernel and XFS (with the exception of down_trylock,
after which xfs_buf_cond_lock was modelled), and replace xfs_buf_lock_val
with an xfs_buf_islocked for use in asserts, or and opencoded variant in
tracing.  remove the XFS_BUF_* wrappers for all the locking helpers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2011-07-08 14:36:19 +02:00
Christoph Hellwig
69ef921b55 xfs: byteswap constants instead of variables
Micro-optimize various comparisms by always byteswapping the constant
instead of the variable, which allows to do the swap at compile instead
of runtime.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2011-07-08 14:36:05 +02:00
Christoph Hellwig
a27a263bae xfs: make log devices with write back caches work
There's no reason not to support cache flushing on external log devices.
The only thing this really requires is flushing the data device first
both in fsync and log commits.  A side effect is that we also have to
remove the barrier write test during mount, which has been superflous
since the new FLUSH+FUA code anyway.  Also use the chance to flush the
RT subvolume write cache before the fsync commit, which is required
for correct semantics.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-06-16 10:52:39 -05:00
Dave Chinner
44396476a0 xfs: reset buffer pointers before freeing them
When we free a vmapped buffer, we need to ensure the vmap address
and length we free is the same as when it was allocated. In various
places in the log code we change the memory the buffer is pointing
to before issuing IO, but we never reset the buffer to point back to
it's original memory (or no memory, if that is the case for the
buffer).

As a result, when we free the buffer it points to memory that is
owned by something else and attempts to unmap and free it. Because
the range does not match any known mapped range, it can trigger
BUG_ON() traps in the vmap code, and potentially corrupt the vmap
area tracking.

Fix this by always resetting these buffers to their original state
before freeing them.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-05-19 12:03:45 -05:00
Christoph Hellwig
97d3ac75e5 xfs: exact busy extent tracking
Update the extent tree in case we have to reuse a busy extent, so that it
always is kept uptodate.  This is done by replacing the busy list searches
with a new xfs_alloc_busy_reuse helper, which updates the busy extent tree
in case of a reuse.  This allows us to allow reusing metadata extents
unconditionally, and thus avoid log forces especially for allocation btree
blocks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-04-28 13:18:04 -05:00
Dave Chinner
da8a1a4a4d xfs: convert log tail checking to a warning
On the Power platform, the log tail debug checks fire excessively
causing the system to panic early in testing. The debug checks are
known to be racy, though on x86_64 there is no evidence that they
trigger at all.

We want to keep the checks active on debug systems to alert us to
problems with log space accounting, but we need to reduce the impact
of a racy check on testing on the Power platform.

As a result, convert the ASSERT conditions to warnings, and
allow them to fire only once per filesystem mount. This will prevent
false positives from interfering with testing, whilst still
providing us with the indication that they may be a problem with log
space accounting should that occur.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
2011-04-08 12:45:07 +10:00
Dave Chinner
fd074841cf xfs: push the AIL from memory reclaim and periodic sync
When we are short on memory, we want to expedite the cleaning of
dirty objects.  Hence when we run short on memory, we need to kick
the AIL flushing into action to clean as many dirty objects as
quickly as possible.  To implement this, sample the lsn of the log
item at the head of the AIL and use that as the push target for the
AIL flush.

Further, we keep items in the AIL that are dirty that are not
tracked any other way, so we can get objects sitting in the AIL that
don't get written back until the AIL is pushed. Hence to get the
filesystem to the idle state, we might need to push the AIL to flush
out any remaining dirty objects sitting in the AIL. This requires
the same push mechanism as the reclaim push.

This patch also renames xfs_trans_ail_tail() to xfs_ail_min_lsn() to
match the new xfs_ail_max_lsn() function introduced in this patch.
Similarly for xfs_trans_ail_push -> xfs_ail_push.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
2011-04-08 12:45:07 +10:00
Dave Chinner
a0fa2b679e xfs: Convert xlog_warn to new logging interface
Convert the xfs log operations to use the new error logging
interfaces. This removes the xlog_{warn,panic} wrappers and makes
almost all errors emit the device they belong to instead of just
refering to "XFS".

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2011-03-07 10:01:35 +11:00
Dave Chinner
73efe4a4dd xfs: prevent NMI timeouts in cmn_err
We currently have a global error message buffer in cmn_err that is
protected by a spin lock that disables interrupts.  Recently there
have been reports of NMI timeouts occurring when the console is
being flooded by SCSI error reports due to cmn_err() getting stuck
trying to print to the console while holding this lock (i.e. with
interrupts disabled). The NMI watchdog is seeing this CPU as
non-responding and so is triggering a panic.  While the trigger for
the reported case is SCSI errors, pretty much anything that spams
the kernel log could cause this to occur.

Realistically the only reason that we have the intemediate message
buffer is to prepend the correct kernel log level prefix to the log
message. The only reason we have the lock is to protect the global
message buffer and the only reason the message buffer is global is
to keep it off the stack. Hence if we can avoid needing a global
message buffer we avoid needing the lock, and we can do this with a
small amount of cleanup and some preprocessor tricks:

	1. clean up xfs_cmn_err() panic mask functionality to avoid
	   needing debug code in xfs_cmn_err()
	2. remove the couple of "!" message prefixes that still exist that
	   the existing cmn_err() code steps over.
	3. redefine CE_* levels directly to KERN_*
	4. redefine cmn_err() and friends to use printk() directly
	   via variable argument length macros.

By doing this, we can completely remove the cmn_err() code and the
lock that is causing the problems, and rely solely on printk()
serialisation to ensure that we don't get garbled messages.

A series of followup patches is really needed to clean up all the
cmn_err() calls and related messages properly, but that results in a
series that is not easily back portable to enterprise kernels. Hence
this initial fix is only to address the direct problem in the lowest
impact way possible.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2011-01-12 08:46:41 -06:00
Dave Chinner
d0eb2f38b2 xfs: convert grant head manipulations to lockless algorithm
The only thing that the grant lock remains to protect is the grant head
manipulations when adding or removing space from the log. These calculations
are already based on atomic variables, so we can already update them safely
without locks. However, the grant head manpulations require atomic multi-step
calculations to be executed, which the algorithms currently don't allow.

To make these multi-step calculations atomic, convert the algorithms to
compare-and-exchange loops on the atomic variables. That is, we sample the old
value, perform the calculation and use atomic64_cmpxchg() to attempt to update
the head with the new value. If the head has not changed since we sampled it,
it will succeed and we are done. Otherwise, we rerun the calculation again from
a new sample of the head.

This allows us to remove the grant lock from around all the grant head space
manipulations, and that effectively removes the grant lock from the log
completely. Hence we can remove the grant lock completely from the log at this
point.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21 12:29:14 +11:00
Dave Chinner
3f16b98507 xfs: introduce new locks for the log grant ticket wait queues
The log grant ticket wait queues are currently protected by the log
grant lock.  However, the queues are functionally independent from
each other, and operations on them only require serialisation
against other queue operations now that all of the other log
variables they use are atomic values.

Hence, we can make them independent of the grant lock by introducing
new locks just to protect the lists operations. because the lists
are independent, we can use a lock per list and ensure that reserve
and write head queuing do not contend.

To ensure forced shutdowns work correctly in conjunction with the
new fast paths, ensure that we check whether the log has been shut
down in the grant functions once we hold the relevant spin locks but
before we go to sleep. This is needed to co-ordinate correctly with
the wakeups that are issued on the ticket queues so we don't leave
any processes sleeping on the queues during a shutdown.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21 12:29:01 +11:00
Dave Chinner
c8a09ff8ca xfs: convert log grant heads to atomic variables
Convert the log grant heads to atomic64_t types in preparation for
converting the accounting algorithms to atomic operations. his patch
just converts the variables; the algorithmic changes are in a
separate patch for clarity.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-04 00:02:40 +11:00
Dave Chinner
1c3cb9ec07 xfs: convert l_tail_lsn to an atomic variable.
log->l_tail_lsn is currently protected by the log grant lock. The
lock is only needed for serialising readers against writers, so we
don't really need the lock if we make the l_tail_lsn variable an
atomic. Converting the l_tail_lsn variable to an atomic64_t means we
can start to peel back the grant lock from various operations.

Also, provide functions to safely crack an atomic LSN variable into
it's component pieces and to recombined the components into an
atomic variable. Use them where appropriate.

This also removes the need for explicitly holding a spinlock to read
the l_tail_lsn on 32 bit platforms.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
2010-12-21 12:28:39 +11:00
Dave Chinner
84f3c683c4 xfs: convert l_last_sync_lsn to an atomic variable
log->l_last_sync_lsn is updated in only one critical spot - log
buffer Io completion - and is protected by the grant lock here. This
requires the grant lock to be taken for every log buffer IO
completion. Converting the l_last_sync_lsn variable to an atomic64_t
means that we do not need to take the grant lock in log buffer IO
completion to update it.

This also removes the need for explicitly holding a spinlock to read
the l_last_sync_lsn on 32 bit platforms.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-03 22:11:29 +11:00
Dave Chinner
2ced19cbae xfs: make AIL tail pushing independent of the grant lock
The xlog_grant_push_ail() currently takes the grant lock internally to sample
the tail lsn, last sync lsn and the reserve grant head. Most of the callers
already hold the grant lock but have to drop it before calling
xlog_grant_push_ail(). This is a left over from when the AIL tail pushing was
done in line and hence xlog_grant_push_ail had to drop the grant lock. AIL push
is now done in another thread and hence we can safely hold the grant lock over
the entire xlog_grant_push_ail call.

Push the grant lock outside of xlog_grant_push_ail() to simplify the locking
and synchronisation needed for tail pushing.  This will reduce traffic on the
grant lock by itself, but this is only one step in preparing for the complete
removal of the grant lock.

While there, clean up the formatting of xlog_grant_push_ail() to match the
rest of the XFS code.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21 12:09:20 +11:00
Dave Chinner
eb40a87500 xfs: use wait queues directly for the log wait queues
The log grant queues are one of the few places left using sv_t
constructs for waiting. Given we are touching this code, we should
convert them to plain wait queues. While there, convert all the
other sv_t users in the log code as well.

Seeing as this removes the last users of the sv_t type, remove the
header file defining the wrapper and the fragments that still
reference it.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21 12:09:01 +11:00
Dave Chinner
a69ed03c24 xfs: combine grant heads into a single 64 bit integer
Prepare for switching the grant heads to atomic variables by
combining the two 32 bit values that make up the grant head into a
single 64 bit variable.  Provide wrapper functions to combine and
split the grant heads appropriately for calculations and use them as
necessary.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21 12:08:20 +11:00
Dave Chinner
663e496a72 xfs: rework log grant space calculations
The log grant space calculations are repeated for both write and
reserve grant heads. To make it simpler to convert the calculations
toa different algorithm, factor them so both the gratn heads use the
same calculation functions. Once this is done we can drop the
wrappers that are used in only a couple of place to update both
grant heads at once as they don't provide any particular value.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21 12:06:05 +11:00
Dave Chinner
3f336c6fa1 xfs: fact out common grant head/log tail verification code
Factor repeated debug code out of grant head manipulation functions into a
separate function. This removes ifdef DEBUG spagetti from the code and makes
the code easier to follow.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21 12:02:52 +11:00
Dave Chinner
1054794198 xfs: convert log grant ticket queues to list heads
The grant write and reserve queues use a roll-your-own double linked
list, so convert it to a standard list_head structure and convert
all the list traversals to use list_for_each_entry(). We can also
get rid of the XLOG_TIC_IN_Q flag as we can use the list_empty()
check to tell if the ticket is in a list or not.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-12-21 12:02:25 +11:00
Linus Torvalds
5fe3a5ae5c Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
* 'for-linus' of git://oss.sgi.com/xfs/xfs: (36 commits)
  xfs: semaphore cleanup
  xfs: Extend project quotas to support 32bit project ids
  xfs: remove xfs_buf wrappers
  xfs: remove xfs_cred.h
  xfs: remove xfs_globals.h
  xfs: remove xfs_version.h
  xfs: remove xfs_refcache.h
  xfs: fix the xfs_trans_committed
  xfs: remove unused t_callback field in struct xfs_trans
  xfs: fix bogus m_maxagi check in xfs_iget
  xfs: do not use xfs_mod_incore_sb_batch for per-cpu counters
  xfs: do not use xfs_mod_incore_sb for per-cpu counters
  xfs: remove XFS_MOUNT_NO_PERCPU_SB
  xfs: pack xfs_buf structure more tightly
  xfs: convert buffer cache hash to rbtree
  xfs: serialise inode reclaim within an AG
  xfs: batch inode reclaim lookup
  xfs: implement batched inode lookups for AG walking
  xfs: split out inode walk inode grabbing
  xfs: split inode AG walking into separate code for reclaim
  ...
2010-10-22 17:32:27 -07:00
Jens Axboe
fa251f8990 Merge branch 'v2.6.36-rc8' into for-2.6.37/barrier
Conflicts:
	block/blk-core.c
	drivers/block/loop.c
	mm/swapfile.c

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-19 09:13:04 +02:00
Christoph Hellwig
1a1a3e97ba xfs: remove xfs_buf wrappers
Stop having two different names for many buffer functions and use
the more descriptive xfs_buf_* names directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-10-18 15:08:07 -05:00
Dave Chinner
686865f76e xfs: rename xfs_buf_get_nodaddr to be more appropriate
xfs_buf_get_nodaddr() is really used to allocate a buffer that is
uncached. While it is not directly assigned a disk address, the fact
that they are not cached is a more important distinction. With the
upcoming uncached buffer read primitive, we should be consistent
with this disctinction.

While there, make page allocation in xfs_buf_get_nodaddr() safe
against memory reclaim re-entrancy into the filesystem by allowing
a flags parameter to be passed.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
2010-10-18 15:07:46 -05:00
Christoph Hellwig
80f6c29d8a xfs: replace barriers with explicit flush / FUA usage
Switch to the WRITE_FLUSH_FUA flag for log writes and remove the EOPNOTSUPP
detection for barriers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10 12:35:38 +02:00
Dave Chinner
a44f13edf0 xfs: Reduce log force overhead for delayed logging
Delayed logging adds some serialisation to the log force process to
ensure that it does not deference a bad commit context structure
when determining if a CIL push is necessary or not. It does this by
grabing the CIL context lock exclusively, then dropping it before
pushing the CIL if necessary. This causes serialisation of all log
forces and pushes regardless of whether a force is necessary or not.
As a result fsync heavy workloads (like dbench) can be significantly
slower with delayed logging than without.

To avoid this penalty, copy the current sequence from the context to
the CIL structure when they are swapped. This allows us to do
unlocked checks on the current sequence without having to worry
about dereferencing context structures that may have already been
freed. Hence we can remove the CIL context locking in the forcing
code and only call into the push code if the current context matches
the sequence we need to force.

By passing the sequence into the push code, we can check the
sequence again once we have the CIL lock held exclusive and abort if
the sequence has already been pushed. This avoids a lock round-trip
and unnecessary CIL pushes when we have racing push calls.

The result is that the regression in dbench performance goes away -
this change improves dbench performance on a ramdisk from ~2100MB/s
to ~2500MB/s. This compares favourably to not using delayed logging
which retuns ~2500MB/s for the same workload.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-08-24 11:40:03 +10:00
Christoph Hellwig
73523a2ecf xfs: fix gcc 4.6 set but not read and unused statement warnings
[hch: dropped a few hunks that need structural changes instead]

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2010-07-26 13:16:51 -05:00
Christoph Hellwig
651701d71d xfs: remove incorrect log write optimization
We do need a barrier for the first buffer of a split log write.
Otherwise we might incorrectly stamp the tail LSN into transactions
in the first part of the split write, or not flush data I/O before
updating the inode size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-07-26 13:16:45 -05:00
Christoph Hellwig
9134c2332e xfs: remove the unused XFS_LOG_SLEEP and XFS_LOG_NOSLEEP flags
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-07-26 13:16:38 -05:00
Christoph Hellwig
4e0d5f926b xfs: fix the xfs_log_iovec i_addr type
By making this member a void pointer we can get rid of a lot of pointless
casts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-07-26 13:16:36 -05:00
Christoph Hellwig
3400777ff0 xfs: remove unneeded #include statements
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
2010-07-26 13:16:33 -05:00
Christoph Hellwig
288699feca xfs: drop dmapi hooks
Dmapi support was never merged upstream, but we still have a lot of hooks
bloating XFS for it, all over the fast pathes of the filesystem.

This patch drops over 700 lines of dmapi overhead.  If we'll ever get HSM
support in mainline at least the namespace events can be done much saner
in the VFS instead of the individual filesystem, so it's not like this
is much help for future work.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-07-26 13:16:33 -05:00
Dave Chinner
9da1ab181a xfs: forced unmounts need to push the CIL
If the filesystem is being shut down and the there is no log error,
the current code forces out the current log buffers. This code now needs
to push the CIL before it forces out the log buffers to acheive the same
result.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-24 10:38:14 -05:00
Dave Chinner
71e330b593 xfs: Introduce delayed logging core code
The delayed logging code only changes in-memory structures and as
such can be enabled and disabled with a mount option. Add the mount
option and emit a warning that this is an experimental feature that
should not be used in production yet.

We also need infrastructure to track committed items that have not
yet been written to the log. This is what the Committed Item List
(CIL) is for.

The log item also needs to be extended to track the current log
vector, the associated memory buffer and it's location in the Commit
Item List. Extend the log item and log vector structures to enable
this tracking.

To maintain the current log format for transactions with delayed
logging, we need to introduce a checkpoint transaction and a context
for tracking each checkpoint from initiation to transaction
completion.  This includes adding a log ticket for tracking space
log required/used by the context checkpoint.

To track all the changes we need an io vector array per log item,
rather than a single array for the entire transaction. Using the new
log vector structure for this requires two passes - the first to
allocate the log vector structures and chain them together, and the
second to fill them out.  This log vector chain can then be passed
to the CIL for formatting, pinning and insertion into the CIL.

Formatting of the log vector chain is relatively simple - it's just
a loop over the iovecs on each log vector, but it is made slightly
more complex because we re-write the iovec after the copy to point
back at the memory buffer we just copied into.

This code also needs to pin log items. If the log item is not
already tracked in this checkpoint context, then it needs to be
pinned. Otherwise it is already pinned and we don't need to pin it
again.

The only other complexity is calculating the amount of new log space
the formatting has consumed. This needs to be accounted to the
transaction in progress, and the accounting is made more complex
becase we need also to steal space from it for log metadata in the
checkpoint transaction. Calculate all this at insert time and update
all the tickets, counters, etc correctly.

Once we've formatted all the log items in the transaction, attach
the busy extents to the checkpoint context so the busy extents live
until checkpoint completion and can be processed at that point in
time. Transactions can then be freed at this point in time.

Now we need to issue checkpoints - we are tracking the amount of log space
used by the items in the CIL, so we can trigger background checkpoints when the
space usage gets to a certain threshold. Otherwise, checkpoints need ot be
triggered when a log synchronisation point is reached - a log force event.

Because the log write code already handles chained log vectors, writing the
transaction is trivial, too. Construct a transaction header, add it
to the head of the chain and write it into the log, then issue a
commit record write. Then we can release the checkpoint log ticket
and attach the context to the log buffer so it can be called during
Io completion to complete the checkpoint.

We also need to allow for synchronising multiple in-flight
checkpoints. This is needed for two things - the first is to ensure
that checkpoint commit records appear in the log in the correct
sequence order (so they are replayed in the correct order). The
second is so that xfs_log_force_lsn() operates correctly and only
flushes and/or waits for the specific sequence it was provided with.

To do this we need a wait variable and a list tracking the
checkpoint commits in progress. We can walk this list and wait for
the checkpoints to change state or complete easily, an this provides
the necessary synchronisation for correct operation in both cases.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-24 10:38:03 -05:00
Dave Chinner
955833cf2a xfs: make the log ticket ID available outside the log infrastructure
The ticket ID is needed to uniquely identify transactions when doing busy
extent matching. Delayed logging changes the lifecycle of busy extents with
respect to the transaction structure lifecycle. Hence we can no longer use
the transaction structure as a means of determining the owner of the busy
extent as it may be freed and reused while the busy extent is still active.

This commit provides the infrastructure to access the xlog_tid_t held in the
ticket from a transaction handle. This avoids the need for callers to peek
into the transaction and log structures to find this out.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-24 10:33:52 -05:00
Dave Chinner
169a7b078e xfs: clean up log ticket overrun debug output
Push the error message output when a ticket overrun is detected
into the ticket printing functions. Also remove the debug version
of the code as the production version will still panic just as
effectively on a debug kernel via the panic mask being set.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-24 10:33:46 -05:00
Dave Chinner
3383ca5780 xfs: allow log ticket allocation to take allocation flags
Delayed logging currently requires ticket allocation to succeed, so
we need to be able to sleep on allocation. It also should not allow
memory allocation to recurse into the filesystem. hence we need to
pass allocation flags directing the type of allocation the caller
requires.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-24 10:33:17 -05:00
Dave Chinner
524ee36fa4 xfs: Don't reuse the same transaction ID for duplicated transactions.
The transaction ID is written into the log as the unique identifier
for transactions during recover. When duplicating a transaction, we
reuse the log ticket, which means it has the same transaction ID as
the previous transaction.

Rather than regenerating a random transaction ID for the duplicated
transaction, just add one to the current ID so that duplicated
transaction can be easily spotted in the log and during recovery
during problem diagnosis.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-24 10:33:10 -05:00
Alex Elder
48389ef175 xfs: kill off l_sectbb_mask
There remains only one user of the l_sectbb_mask field in the log
structure.  Just kill it off and compute the mask where needed from
the power-of-2 sector size.

(Only update from last post is to accomodate the changes in the
previous patch in the series.)

Signed-off-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19 09:58:16 -05:00
Alex Elder
69ce58f08a xfs: record log sector size rather than log2(that)
Change struct log so it keeps track of the size (in basic blocks) of
a log sector in l_sectBBsize rather than the log-base-2 of that
value (previously, l_sectbb_log).  The name was chosen for
consistency with the other fields in the structure that represent
a number of basic blocks.

(Updated so that a variable used in computing and verifying a log's
sector size is named "log2_size".  Also added the "BB" to the
structure field name, based on feedback from Eric Sandeen.  Also
dropped some superfluous parentheses.)

Signed-off-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
2010-05-19 09:58:15 -05:00
Dave Chinner
f983710758 xfs: make the log ticket transaction id random
The transaction ID that is written to the log for a transaction is
currently set by taking the lower 32 bits of the memory address of
the ticket structure.  This is not guaranteed to be unique as
tickets comes from a slab and slots can be reallocated immediately
after being freed. As a result, there is no guarantee of uniqueness
in the ticket ID value.

Fix this by assigning a random number to the ticket ID field so that
it is extremely unlikely that duplicates will occur and remove the
possibility of transactions being mixed up during recovery due to
duplicate IDs.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19 09:58:13 -05:00
Christoph Hellwig
e6b1f27370 xfs: clean up xlog_write_adv_cnt
Replace the awkward xlog_write_adv_cnt with an inline helper that makes
it more obvious that it's modifying it's paramters, and replace the use
of an integer type for "ptr" with a real void pointer.  Also move
xlog_write_adv_cnt to xfs_log_priv.h as it will be used outside of
xfs_log.c in the delayed logging series.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-05-19 09:58:10 -05:00
Dave Chinner
55b66332d0 xfs: introduce new internal log vector structure
The current log IO vector structure is a flat array and not
extensible. To make it possible to keep separate log IO vectors for
individual log items, we need a method of chaining log IO vectors
together.

Introduce a new log vector type that can be used to wrap the
existing log IO vectors on use that internally to the log. This
means that the existing external interface (xfs_log_write) does not
change and hence no changes to the transaction commit code are
required.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-05-19 09:58:10 -05:00
Christoph Hellwig
99428ad0f6 xfs: reindent xlog_write
Reindent xlog_write to normal one tab indents and move all variable
declarations into the closest enclosing block.

Split from a bigger patch by Dave Chinner.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-05-19 09:58:10 -05:00
Dave Chinner
b5203cd0a4 xfs: factor xlog_write
xlog_write is a mess that takes a lot of effort to understand. It is
a mass of nested loops with 4 space indents to get it to fit in 80 columns
and lots of funky variables that aren't obvious what they mean or do.

Break it down into understandable chunks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2010-05-19 09:58:09 -05:00
Dave Chinner
9b9fc2b760 xfs: log ticket reservation underestimates the number of iclogs
When allocation a ticket for a transaction, the ticket is initialised with the
worst case log space usage based on the number of bytes the transaction may
consume. Part of this calculation is the number of log headers required for the
iclog space used up by the transaction.

This calculation makes an undocumented assumption that if the transaction uses
the log header space reservation on an iclog, then it consumes either the
entire iclog or it completes. That is - the transaction that is first in an
iclog is the transaction that the log header reservation is accounted to. If
the transaction is larger than the iclog, then it will use the entire iclog
itself. Document this assumption.

Further, the current calculation uses the rule that we can fit iclog_size bytes
of transaction data into an iclog. This is in correct - the amount of space
available in an iclog for transaction data is the size of the iclog minus the
space used for log record headers. This means that the calculation is out by
512 bytes per 32k of log space the transaction can consume. This is rarely an
issue because maximally sized transactions are extremely uncommon, and for 4k
block size filesystems maximal transaction reservations are about 400kb. Hence
the error in this case is less than the size of an iclog, so that makes it even
harder to hit.

However, anyone using larger directory blocks (16k directory blocks push the
maximum transaction size to approx. 900k on a 4k block size filesystem) or
larger block size (e.g. 64k blocks push transactions to the 3-4MB size) could
see the error grow to more than an iclog and at this point the transaction is
guaranteed to get a reservation underrun and shutdown the filesystem.

Fix this by adjusting the calculation to calculate the correct number of iclogs
required and account for them all up front.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19 09:58:09 -05:00
Dave Chinner
43f5efc5b5 xfs: factor log item initialisation
Each log item type does manual initialisation of the log item.
Delayed logging introduces new fields that need initialisation, so
factor all the open coded initialisation into a common function
first.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2010-05-19 09:58:07 -05:00
Dave Chinner
b6f8dd49db xfs: ensure that sync updates the log tail correctly
Updates to the VFS layer removed an extra ->sync_fs call into the
filesystem during the sync process (from the quota code).
Unfortunately the sync code was unknowingly relying on this call to
make sure metadata buffers were flushed via a xfs_buftarg_flush()
call to move the tail of the log forward in memory before the final
transactions of the sync process were issued.

As a result, the old code would write a very recent log tail value
to the log by the end of the sync process, and so a subsequent crash
would leave nothing for log recovery to do. Hence in qa test 182,
log recovery only replayed a small handle for inode fsync
transactions in this case.

However, with the removal of the extra ->sync_fs call, the log tail
was now not moved forward with the inode fsync transactions near the
end of the sync procese the first (and only) buftarg flush occurred
after these transactions went to disk. The result is that log
recovery now sees a large number of transactions for metadata that
is already on disk.

This usually isn't a problem, but when the transactions include
inode chunk allocation, the inode create transactions and all
subsequent changes are replayed as we cannt rely on what is on disk
is valid. As a result, if the inode was written and contains
unlogged changes, the unlogged changes are lost, thereby violating
sync semantics.

The fix is to always issue a transaction after the buftarg flush
occurs is the log iѕ not idle or covered. This results in a dummy
transaction being written that contains the up-to-date log tail
value, which will be very recent. Indeed, it will be at least as
recent as the old code would have left on disk, so log recovery
will behave exactly as it used to in this situation.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-04-16 13:51:23 -05:00
Christoph Hellwig
35a8a72f06 xfs: stop passing opaque handles to xfs_log.c routines
Currenly we pass opaque xfs_log_ticket_t handles instead of
struct xlog_ticket pointers, and void pointers instead of
struct xlog_in_core pointers to various log manager functions.
Instead pass properly typed pointers after adding forward
declarations for them to xfs_log.h, and adjust the touched
function prototypes to the standard XFS style while at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-03-01 16:35:32 -06:00
Christoph Hellwig
a14a348bff xfs: cleanup up xfs_log_force calling conventions
Remove the XFS_LOG_FORCE argument which was always set, and the
XFS_LOG_URGE define, which was never used.

Split xfs_log_force into a two helpers - xfs_log_force which forces
the whole log, and xfs_log_force_lsn which forces up to the
specified LSN.  The underlying implementations already were entirely
separate, as were the users.

Also re-indent the new _xfs_log_force/_xfs_log_force which
previously had a weird coding style.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-21 13:44:49 -06:00
Christoph Hellwig
4139b3b337 xfs: kill XLOG_VEC_SET_TYPE
This macro only obsfucates the log item type assignments, so kill it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-21 13:44:43 -06:00
Christoph Hellwig
873ff5501d xfs: clean up log buffer writes
Don't bother using XFS_bwrite as it doesn't provide much code for
our use case.  Instead opencode it and fold xlog_bdstrat_cb into the
new xlog_bdstrat helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-01-15 15:34:54 -06:00
Dave Chinner
2ee1abad73 xfs: improve metadata I/O merging in the elevator
Change all async metadata buffers to use [READ|WRITE]_META I/O types
so that the I/O doesn't get issued immediately. This allows merging of
adjacent metadata requests but still prioritises them over bulk data.
This shows a 10-15% improvement in sequential create speed of small
files.

Don't include the log buffers in this classification - leave them as
sync types so they are issued immediately.

Signed-off-by: Dave Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2009-12-16 13:41:19 -06:00
Christoph Hellwig
0b1b213fcf xfs: event tracing support
Convert the old xfs tracing support that could only be used with the
out of tree kdb and xfsidbg patches to use the generic event tracer.

To use it make sure CONFIG_EVENT_TRACING is enabled and then enable
all xfs trace channels by:

   echo 1 > /sys/kernel/debug/tracing/events/xfs/enable

or alternatively enable single events by just doing the same in one
event subdirectory, e.g.

   echo 1 > /sys/kernel/debug/tracing/events/xfs/xfs_ihold/enable

or set more complex filters, etc. In Documentation/trace/events.txt
all this is desctribed in more detail.  To reads the events do a

   cat /sys/kernel/debug/tracing/trace

Compared to the last posting this patch converts the tracing mostly to
the one tracepoint per callsite model that other users of the new
tracing facility also employ.  This allows a very fine-grained control
of the tracing, a cleaner output of the traces and also enables the
perf tool to use each tracepoint as a virtual performance counter,
     allowing us to e.g. count how often certain workloads git various
     spots in XFS.  Take a look at

    http://lwn.net/Articles/346470/

for some examples.

Also the btree tracing isn't included at all yet, as it will require
additional core tracing features not in mainline yet, I plan to
deliver it later.

And the really nice thing about this patch is that it actually removes
many lines of code while adding this nice functionality:

 fs/xfs/Makefile                |    8
 fs/xfs/linux-2.6/xfs_acl.c     |    1
 fs/xfs/linux-2.6/xfs_aops.c    |   52 -
 fs/xfs/linux-2.6/xfs_aops.h    |    2
 fs/xfs/linux-2.6/xfs_buf.c     |  117 +--
 fs/xfs/linux-2.6/xfs_buf.h     |   33
 fs/xfs/linux-2.6/xfs_fs_subr.c |    3
 fs/xfs/linux-2.6/xfs_ioctl.c   |    1
 fs/xfs/linux-2.6/xfs_ioctl32.c |    1
 fs/xfs/linux-2.6/xfs_iops.c    |    1
 fs/xfs/linux-2.6/xfs_linux.h   |    1
 fs/xfs/linux-2.6/xfs_lrw.c     |   87 --
 fs/xfs/linux-2.6/xfs_lrw.h     |   45 -
 fs/xfs/linux-2.6/xfs_super.c   |  104 ---
 fs/xfs/linux-2.6/xfs_super.h   |    7
 fs/xfs/linux-2.6/xfs_sync.c    |    1
 fs/xfs/linux-2.6/xfs_trace.c   |   75 ++
 fs/xfs/linux-2.6/xfs_trace.h   | 1369 +++++++++++++++++++++++++++++++++++++++++
 fs/xfs/linux-2.6/xfs_vnode.h   |    4
 fs/xfs/quota/xfs_dquot.c       |  110 ---
 fs/xfs/quota/xfs_dquot.h       |   21
 fs/xfs/quota/xfs_qm.c          |   40 -
 fs/xfs/quota/xfs_qm_syscalls.c |    4
 fs/xfs/support/ktrace.c        |  323 ---------
 fs/xfs/support/ktrace.h        |   85 --
 fs/xfs/xfs.h                   |   16
 fs/xfs/xfs_ag.h                |   14
 fs/xfs/xfs_alloc.c             |  230 +-----
 fs/xfs/xfs_alloc.h             |   27
 fs/xfs/xfs_alloc_btree.c       |    1
 fs/xfs/xfs_attr.c              |  107 ---
 fs/xfs/xfs_attr.h              |   10
 fs/xfs/xfs_attr_leaf.c         |   14
 fs/xfs/xfs_attr_sf.h           |   40 -
 fs/xfs/xfs_bmap.c              |  507 +++------------
 fs/xfs/xfs_bmap.h              |   49 -
 fs/xfs/xfs_bmap_btree.c        |    6
 fs/xfs/xfs_btree.c             |    5
 fs/xfs/xfs_btree_trace.h       |   17
 fs/xfs/xfs_buf_item.c          |   87 --
 fs/xfs/xfs_buf_item.h          |   20
 fs/xfs/xfs_da_btree.c          |    3
 fs/xfs/xfs_da_btree.h          |    7
 fs/xfs/xfs_dfrag.c             |    2
 fs/xfs/xfs_dir2.c              |    8
 fs/xfs/xfs_dir2_block.c        |   20
 fs/xfs/xfs_dir2_leaf.c         |   21
 fs/xfs/xfs_dir2_node.c         |   27
 fs/xfs/xfs_dir2_sf.c           |   26
 fs/xfs/xfs_dir2_trace.c        |  216 ------
 fs/xfs/xfs_dir2_trace.h        |   72 --
 fs/xfs/xfs_filestream.c        |    8
 fs/xfs/xfs_fsops.c             |    2
 fs/xfs/xfs_iget.c              |  111 ---
 fs/xfs/xfs_inode.c             |   67 --
 fs/xfs/xfs_inode.h             |   76 --
 fs/xfs/xfs_inode_item.c        |    5
 fs/xfs/xfs_iomap.c             |   85 --
 fs/xfs/xfs_iomap.h             |    8
 fs/xfs/xfs_log.c               |  181 +----
 fs/xfs/xfs_log_priv.h          |   20
 fs/xfs/xfs_log_recover.c       |    1
 fs/xfs/xfs_mount.c             |    2
 fs/xfs/xfs_quota.h             |    8
 fs/xfs/xfs_rename.c            |    1
 fs/xfs/xfs_rtalloc.c           |    1
 fs/xfs/xfs_rw.c                |    3
 fs/xfs/xfs_trans.h             |   47 +
 fs/xfs/xfs_trans_buf.c         |   62 -
 fs/xfs/xfs_vnodeops.c          |    8
 70 files changed, 2151 insertions(+), 2592 deletions(-)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2009-12-14 23:08:16 -06:00
Christoph Hellwig
a8914f3a6d xfs: fix spin_is_locked assert on uni-processor builds
Without SMP or preemption spin_is_locked always returns false,
so we can't do an assert with it.  Instead use assert_spin_locked,
which does the right thing on all builds.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Reported-by: Johannes Engel <jcnengel@googlemail.com>
Tested-by: Johannes Engel <jcnengel@googlemail.com>
Signed-off-by: Felix Blyakher <felixb@sgi.com>
2009-08-12 01:08:27 -05:00
Dave Chinner
9d7fef74b2 xfs: inform the xfsaild of the push target before sleeping
When trying to reserve log space, we find the amount of space
we need, then go to sleep waiting for space. When we are
woken, we try to push the tail of the log forward to make
sure we have space available.

Unfortunately, this means that if there is not space available, and
everyone who needs space goes to sleep there is no-one left to push
the tail of the log to make space available. Once we have a thread
waiting for space to become available, the others queue up behind
it in a FIFO, and none of them push the tail of the log.

This can result in everyone going to sleep in xlog_grant_log_space()
if the first sleeper races with the last I/O that moves the tail
of the log forward. With no further I/O tomove the tail of the log,
there is nothing to wake the sleepers and hence all transactions
just stop.

Fix this by making sure the xfsaild will create enough space for the
transaction that is about to sleep by moving the push target far
enough forwards to ensure that that the curent proceeees will have
enough space available when it is woken. That is, we push the
AIL before we go to sleep.

Because we've inserted the log ticket into the queue before we've
pushed and gone to sleep, subsequent transactions will wait behind
this one. Hence we are guaranteed to have space available when we
are woken.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2009-04-06 18:42:59 +02:00
Dave Chinner
a6cb767e24 xfs: validate log feature fields correctly
If the large log sector size feature bit is set in the
superblock by accident (say disk corruption), the then
fields that are now considered valid are not checked on
production kernels. The checks are present as ASSERT
statements so cause a panic on a debug kernel.

Change this so that the fields are validity checked if
the feature bit is set and abort the log mount if the
fields do not contain valid values.

Reported-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2009-04-06 18:39:27 +02:00
Malcolm Parsons
9da096fd13 xfs: fix various typos
Signed-off-by: Malcolm Parsons <malcolm.parsons@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2009-03-29 09:55:42 +02:00
Christoph Hellwig
21b699c895 xfs: cleanup log unmount handling
Kill the current xfs_log_unmount wrapper and opencode the two function
calls in the only caller.  Rename the current xfs_log_unmount_dealloc to
xfs_log_unmount as it undoes xfs_log_mount and the new name makes that
more clear.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
2009-03-16 08:19:29 +01:00
Christoph Hellwig
264307520b xfs: fix error handling in xfs_log_mount
We can't just call xfs_log_unmount_dealloc on any failure because the
ail thread which is torn down by xfs_log_unmount_dealloc might not
be initialized yet.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Felix Blyakher <felixb@sgi.com>
Reported-by: Lachlan McIlroy <lachlan@sgi.com>
2009-02-12 19:55:48 +01:00
Christoph Hellwig
7153f8ba2b xfs: remove iclog calculation special cases
Our default has been to always use 8 32KB log buffers for a while now, so
remove the special casing for larger block size filesystem to use the same
or even lower number of buffers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
2009-02-09 08:36:46 +01:00
Christoph Hellwig
39e2defe73 reduce l_icloglock roundtrips
All but one caller of xlog_state_want_sync drop and re-acquire
l_icloglock around the call to it, just so that xlog_state_want_sync can
acquire and drop it.

Move all lock operation out of l_icloglock and assert that the lock is
held when it is called.

Note that it would make sense to extende this scheme to
xlog_state_release_iclog, but the locking in there is more complicated
and we'd like to keep the atomic_dec_and_lock optmization for those
callers not having l_icloglock yet.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
2008-12-04 15:39:21 +11:00
Christoph Hellwig
b28708d6a0 [XFS] sanitize xlog_in_core_t definition
Move all fields from xlog_iclog_fields_t into xlog_in_core_t instead of having
them in a substructure and the using #defines to make it look like they were
directly in xlog_in_core_t.  Also document that xlog_in_core_2_t is grossly
misnamed, and make all references to it typesafe.

(First sent on Semptember 15th)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
2008-12-01 11:37:25 +11:00
Christoph Hellwig
bac8dca9f9 [XFS] fix NULL pointer dereference in xfs_log_force_umount
xfs_log_force_umount may be called very early during log recovery where

If we fail a buffer read in xlog_recover_do_inode_trans we abort the mount.
But at that point log recovery has started delayed writeback of inode
buffers.   As part of the aborted mount we try to flush out all delwri
buffers, but at that point we have already freed the superblock, and set
mp->m_sb_bp to NULL, and xfs_log_force_umount which gets called after
the inode buffer writeback trips over it.

Make xfs_log_force_umount a little more careful when accessing mp->m_sb_bp
to avoid this.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
2008-12-01 11:06:44 +11:00
Dave Chinner
cc09c0dc57 [XFS] Fix double free of log tickets
When an I/O error occurs during an intermediate commit on a rolling
transaction, xfs_trans_commit() will free the transaction structure
and the related ticket. However, the duplicate transaction that
gets used as the transaction continues still contains a pointer
to the ticket. Hence when the duplicate transaction is cancelled
and freed, we free the ticket a second time.

Add reference counting to the ticket so that we hold an extra
reference to the ticket over the transaction commit. We drop the
extra reference once we have checked that the transaction commit
did not return an error, thus avoiding a double free on commit
error.

Credit to Nick Piggin for tripping over the problem.

SGI-PV: 989741

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-11-17 17:37:10 +11:00
Dave Chinner
644c3567d1 [XFS] handle memory allocation failures during log initialisation
When there is no memory left in the system, xfs_buf_get_noaddr()
can fail. If this happens at mount time during xlog_alloc_log()
we fail to catch the error and oops.

Catch the error from xfs_buf_get_noaddr(), and allow other memory
allocations to fail and catch those errors too. Report the error
to the console and fail the mount with ENOMEM.

Tested by manually injecting errors into xfs_buf_get_noaddr() and
xlog_alloc_log().

Version 2:
o remove unnecessary casts of the returned pointer from kmem_zalloc()

SGI-PV: 987246

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-11-10 16:50:24 +11:00
David Chinner
783a2f656f [XFS] Finish removing the mount pointer from the AIL API
Change all the remaining AIL API functions that are passed struct
xfs_mount pointers to pass pointers directly to the struct xfs_ail being
used. With this conversion, all external access to the AIL is via the
struct xfs_ail. Hence the operation and referencing of the AIL is almost
entirely independent of the xfs_mount that is using it - it is now much
more tightly tied to the log and the items it is tracking in the log than
it is tied to the xfs_mount.

SGI-PV: 988143

SGI-Modid: xfs-linux-melb:xfs-kern:32353a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
2008-10-30 17:39:58 +11:00
David Chinner
a9c21c1b9d [XFS] Given the log a pointer to the AIL
When we need to go from the log to the AIL, we have to go via the
xfs_mount. Add a xfs_ail pointer to the log so we can go directly to the
AIL associated with the log.

SGI-PV: 988143

SGI-Modid: xfs-linux-melb:xfs-kern:32351a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
2008-10-30 17:39:35 +11:00
David Chinner
c7e8f26827 [XFS] Move the AIL lock into the struct xfs_ail
Bring the ail lock inside the struct xfs_ail. This means the AIL can be
entirely manipulated via the struct xfs_ail rather than needing both the
struct xfs_mount and the struct xfs_ail.

SGI-PV: 988143

SGI-Modid: xfs-linux-melb:xfs-kern:32350a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
2008-10-30 17:39:23 +11:00
David Chinner
5b00f14fbd [XFS] move the AIl traversal over to a consistent interface
With the new cursor interface, it makes sense to make all the traversing
code use the cursor interface and make the old one go away. This means
more of the AIL interfacing is done by passing struct xfs_ail pointers
around the place instead of struct xfs_mount pointers.

We can replace the use of xfs_trans_first_ail() in xfs_log_need_covered()
as it is only checking if the AIL is empty. We can do that with a call to
xfs_trans_ail_tail() instead, where a zero LSN returned indicates and
empty AIL...

SGI-PV: 988143

SGI-Modid: xfs-linux-melb:xfs-kern:32348a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
2008-10-30 17:39:00 +11:00
David Chinner
27d8d5fe0e [XFS] Use a cursor for AIL traversal.
To replace the current generation number ensuring sanity of the AIL
traversal, replace it with an external cursor that is linked to the AIL.

Basically, we store the next item in the cursor whenever we want to drop
the AIL lock to do something to the current item. When we regain the lock.
the current item may already be free, so we can't reference it, but the
next item in the traversal is already held in the cursor.

When we move or delete an object, we search all the active cursors and if
there is an item match we clear the cursor(s) that point to the object.
This forces the traversal to restart transparently.

We don't invalidate the cursor on insert because the cursor still points
to a valid item. If the intem is inserted between the current item and the
cursor it does not matter; the traversal is considered to be past the
insertion point so it will be picked up in the next traversal.

Hence traversal restarts pretty much disappear altogether with this method
of traversal, which should substantially reduce the overhead of pushing on
a busy AIL.

Version 2 o add restart logic o comment cursor interface o minor cleanups

SGI-PV: 988143

SGI-Modid: xfs-linux-melb:xfs-kern:32347a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
2008-10-30 17:38:39 +11:00
Christoph Hellwig
73f6aa4d44 Fix barrier fail detection in XFS
Currently we disable barriers as soon as we get a buffer in xlog_iodone
that has the XBF_ORDERED flag cleared.  But this can be the case not only
for buffers where the barrier failed, but also the first buffer of a
split log write in case of a log wraparound.  Due to the disabled
barriers we can easily get directory corruption on unclean shutdowns.
So instead of using this check add a new buffer flag for failed barrier
writes.

This is a regression vs 2.6.26 caused by patch to use the right macro
to check for the ORDERED flag, as we previously got true returned for
every buffer.

Thanks to Toei Rei for reporting the bug.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: David Chinner <david@fromorbit.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-10 11:08:07 -07:00
David Chinner
b5b8c9acd5 [XFS] Fix barrier status change detection.
The current code in xlog_iodone() uses the wrong macro to check if the
barrier has been cleared due to an EOPNOTSUPP error form the lower layer.

SGI-PV: 986143

SGI-Modid: xfs-linux-melb:xfs-kern:31984a

Signed-off-by: David Chinner <david@fromorbit.com>
Signed-off-by: Nathaniel W. Turner <nate@houseofnate.net>
Signed-off-by: Peter Leckie <pleckie@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-09-17 16:50:50 +10:00
Lachlan McIlroy
31bd61f2bb [XFS] Move memory allocations for log tracing out of the critical path
Memory allocations for log->l_grant_trace and iclog->ic_trace are done on
demand when the first event is logged. In xlog_state_get_iclog_space() we
call xlog_trace_iclog() under a spinlock and allocating memory here can
cause us to sleep with a spinlock held and deadlock the system.

For the log grant tracing we use KM_NOSLEEP but that means we can lose
trace entries. Since there is no locking to serialize the log grant
tracing we could race and have multiple allocations and leak memory.

So move the allocations to where we initialize the log/iclog structures.
Use KM_NOFS to avoid recursing into the filesystem and drop log->l_trace
since it's not even used.

SGI-PV: 983738

SGI-Modid: xfs-linux-melb:xfs-kern:31896a

Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
2008-09-17 16:45:37 +10:00
Lachlan McIlroy
c6a7b0f8a4 [XFS] Fix use after free in xfs_log_done().
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: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
2008-08-13 16:52:50 +10:00
Lachlan McIlroy
5695ef46ef [XFS] Use KM_NOFS for debug trace buffers
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: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
2008-08-13 16:51:57 +10:00
Christoph Hellwig
4249023a5d [XFS] cleanup xfs_mountfs
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: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-08-13 16:49:32 +10:00
David Chinner
12017faf38 [XFS] clean up stale references to semaphores
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: David Chinner <david@fromorbit.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-08-13 16:34:31 +10:00
Matthew Wilcox
d748c62367 [XFS] Convert l_flushsema to a sv_t
The l_flushsema doesn't exactly have completion semantics, nor mutex
semantics. It's used as a list of tasks which are waiting to be notified
that a flush has completed. It was also being used in a way that was
potentially racy, depending on the semaphore implementation.

By using a sv_t instead of a semaphore we avoid the need for a separate
counter, since we know we just need to wake everything on the queue.

Original waitqueue implementation from Matthew Wilcox. Cleanup and
conversion to sv_t by Christoph Hellwig.

SGI-PV: 981507
SGI-Modid: xfs-linux-melb:xfs-kern:31059a

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-07-28 16:58:12 +10:00
Michael Nishimoto
d729eae893 [XFS] Ensure that 2 GiB xfs logs work properly.
We found this while experimenting with 2GiB xfs logs. The previous code
never assumed that xfs logs would ever get so large.

SGI-PV: 981502
SGI-Modid: xfs-linux-melb:xfs-kern:31058a

Signed-off-by: Michael Nishimoto <miken@agami.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-07-28 16:58:11 +10:00
Denys Vlasenko
f0e2d93c29 [XFS] Remove unused arg from kmem_free()
kmem_free() function takes (ptr, size) arguments but doesn't actually use
second one.

This patch removes size argument from all callsites.

SGI-PV: 981498
SGI-Modid: xfs-linux-melb:xfs-kern:31050a

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-07-28 16:58:07 +10:00
Dave Chinner
49641f1acf Fix reference counting race on log buffers
When we release the iclog, we do an atomic_dec_and_lock to determine if
we are the last reference and need to trigger update of log headers and
writeout.  However, in xlog_state_get_iclog_space() we also need to
check if we have the last reference count there.  If we do, we release
the log buffer, otherwise we decrement the reference count.

But the compare and decrement in xlog_state_get_iclog_space() is not
atomic, so both places can see a reference count of 2 and neither will
release the iclog.  That leads to a filesystem hang.

Close the race by replacing the atomic_read() and atomic_dec() pair with
atomic_add_unless() to ensure that they are executed atomically.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Tim Shimmin <tes@sgi.com>
Tested-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-11 11:37:18 -07:00
David Chinner
1bb7d6b5a8 [XFS] Catch log unmount failures.
Unmounting the log can fail. unlikely, but it can. Catch all the error
conditions an make sure it's propagated upwards.

SGI-PV: 980084
SGI-Modid: xfs-linux-melb:xfs-kern:30833a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-18 12:02:30 +10:00
David Chinner
b911ca0472 [XFS] Sanitise xfs_log_force error checking.
xfs_log_force() is declared to return an error, but we almost never check
it. We don't need to check it in most cases; if there's a log I/O error
then we'll be shutting down the filesystem anyway and that means we'll
catch the error somewhere else.

However, on certain calls we should be returning an error - sync
transactions, fsync, sync writes, etc. so this isn't a pure black and
white distinction. Hence make xfs_log_force() a void function that issues
a warning to the syslog on error, and call _xfs_log_force() in all the
places where we actually care about the error status returned.

SGI-PV: 980084
SGI-Modid: xfs-linux-melb:xfs-kern:30832a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-18 12:02:20 +10:00
Harvey Harrison
34a622b2e1 [XFS] replace remaining __FUNCTION__ occurrences
__FUNCTION__ is gcc-specific, use __func__

SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30775a

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-18 11:51:26 +10:00
David Chinner
6b1d1a732f [XFS] Fix lock inversion in forced shutdown.
Recent changes to xlog_state_release_iclog() placed the grant_lock inside
the icloglock. forced unmount of the log does this the opposite way
around, but does not depend on the order for correct working. Fix the
inversion by changing the order locks are gained in
xfs_log_force_umount().

SGI-PV: 979661
SGI-Modid: xfs-linux-melb:xfs-kern:30773a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-18 11:51:04 +10:00
David Chinner
4679b2d36d [XFS] Reorganise xlog_t for better cacheline isolation of contention
To reduce contention on the log in large CPU count, separate out different
parts of the xlog_t structure onto different cachelines. Move each lock
onto a different cacheline along with all the members that are
accessed/modified while that lock is held.

Also, move the debugging code into debug code.

SGI-PV: 978729
SGI-Modid: xfs-linux-melb:xfs-kern:30772a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-18 11:50:53 +10:00
David Chinner
eb01c9cd87 [XFS] Remove the xlog_ticket allocator
The ticket allocator is just a simple slab implementation internal to the
log. It requires the icloglock to be held when manipulating it and this
contributes to contention on that lock.

Just kill the entire allocator and use a memory zone instead. While there,
allow us to gracefully fail allocation with ENOMEM.

SGI-PV: 978729
SGI-Modid: xfs-linux-melb:xfs-kern:30771a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-18 11:50:39 +10:00
David Chinner
114d23aae5 [XFS] Per iclog callback chain lock
Rather than use the icloglock for protecting the iclog completion callback
chain, use a new per-iclog lock so that walking the callback chain doesn't
require holding a global lock.

This reduces contention on the icloglock during transaction commit and log
I/O completion by reducing the number of times we need to hold the global
icloglock during these operations.

SGI-PV: 978729
SGI-Modid: xfs-linux-melb:xfs-kern:30770a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-18 11:50:22 +10:00
David Chinner
155cc6b784 [XFS] Use atomics for iclog reference counting
Now that we update the log tail LSN less frequently on transaction
completion, we pass the contention straight to the global log state lock
(l_iclog_lock) during transaction completion.

We currently have to take this lock to decrement the iclog reference
count. there is a reference count on each iclog, so we need to take þhe
global lock for all refcount changes.

When large numbers of processes are all doing small trnasctions, the iclog
reference counts will be quite high, and the state change that absolutely
requires the l_iclog_lock is the except rather than the norm.

Change the reference counting on the iclogs to use atomic_inc/dec so that
we can use atomic_dec_and_lock during transaction completion and avoid the
need for grabbing the l_iclog_lock for every reference count decrement
except the one that matters - the last.

SGI-PV: 975671
SGI-Modid: xfs-linux-melb:xfs-kern:30505a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-18 11:38:10 +10:00
David Chinner
b589334c7a [XFS] Prevent AIL lock contention during transaction completion
When hundreds of processors attempt to commit transactions at the same
time, they can contend on the AIL lock when updating the tail LSN held in
the in-core log structure.

At the moment, the tail LSN is only needed when actually writing out an
iclog, so it really does not need to be updated on every single
transaction completion - only those that result in switching iclogs and
flushing them to disk.

The result is that we reduce the number of times we need to grab the AIL
lock and the log grant lock by up to two orders of magnitude on large
processor count machines. The problem has previously been hidden by AIL
lock contention walking the AIL list which was recently solved and
uncovered this issue.

SGI-PV: 975671
SGI-Modid: xfs-linux-melb:xfs-kern:30504a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-18 11:38:01 +10:00
Eric Sandeen
6211870992 [XFS] remove shouting-indirection macros from xfs_sb.h
Remove macro-to-small-function indirection from xfs_sb.h, and remove some
which are completely unused.

SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30528a

Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-04-10 16:24:45 +10:00
Marcin Slusarz
413d57c990 xfs: convert beX_add to beX_add_cpu (new common API)
remove beX_add functions and replace all uses with beX_add_cpu

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Reviewed-by: Dave Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-13 16:21:19 -08:00
David Chinner
249a8c1124 [XFS] Move AIL pushing into it's own thread
When many hundreds to thousands of threads all try to do simultaneous
transactions and the log is in a tail-pushing situation (i.e. full), we
can get multiple threads walking the AIL list and contending on the AIL
lock.

The AIL push is, in effect, a simple I/O dispatch algorithm complicated by
the ordering constraints placed on it by the transaction subsystem. It
really does not need multiple threads to push on it - even when only a
single CPU is pushing the AIL, it can push the I/O out far faster that
pretty much any disk subsystem can handle.

So, to avoid contention problems stemming from multiple list walkers, move
the list walk off into another thread and simply provide a "target" to
push to. When a thread requires a push, it sets the target and wakes the
push thread, then goes to sleep waiting for the required amount of space
to become available in the log.

This mechanism should also be a lot fairer under heavy load as the waiters
will queue in arrival order, rather than queuing in "who completed a push
first" order.

Also, by moving the pushing to a separate thread we can do more
effectively overload detection and prevention as we can keep context from
loop iteration to loop iteration. That is, we can push only part of the
list each loop and not have to loop back to the start of the list every
time we run. This should also help by reducing the number of items we try
to lock and/or push items that we cannot move.

Note that this patch is not intended to solve the inefficiencies in the
AIL structure and the associated issues with extremely large list
contents. That needs to be addresses separately; parallel access would
cause problems to any new structure as well, so I'm only aiming to isolate
the structure from unbounded parallelism here.

SGI-PV: 972759
SGI-Modid: xfs-linux-melb:xfs-kern:30371a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-02-07 18:22:51 +11:00
Tim Shimmin
e6a4b37f38 [XFS] Remove the BPCSHIFT and NB* based macros from XFS.
The BPCSHIFT based macros, btoc*, ctob*, offtoc* and ctooff are either not
used or don't need to be used. The NDPP, NDPP, NBBY macros don't need to
be used but instead are replaced directly by PAGE_SIZE and PAGE_CACHE_SIZE
where appropriate. Initial patch and motivation from Nicolas Kaiser.

SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:30096a

Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-02-07 18:17:58 +11:00
Niv Sardi
f7b7c3673e [XFS] Remove bogus assert
This assert is bogus. We can have a forced shutdown occur
between the check for the XLOG_FORCED_SHUTDOWN and the ASSERT. Also, the
logging system shouldn't care about the state of XFS_FORCED_SHUTDOWN, it
should only check XLOG_FORCED_SHUTDOWN. The logging system has it's own
forced shutdown flag so, for the case of a forced shutdown that's not due
to a logging error, we can flush the log.

SGI-PV: 972985
SGI-Modid: xfs-linux-melb:xfs-kern:30029a

Signed-off-by: Niv Sardi <xaiki@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-02-07 18:17:39 +11:00
David Chinner
a8272ce0c1 [XFS] Fix up sparse warnings.
These are mostly locking annotations, marking things static, casts where
needed and declaring stuff in header files.

SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:30002a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
2008-02-07 18:14:38 +11:00
Christoph Hellwig
b53e675dc8 [XFS] xlog_rec_header/xlog_rec_ext_header endianess annotations
Mostly trivial conversion with one exceptions: h_num_logops was kept in
native endian previously and only converted to big endian in xlog_sync,
but we always keep it big endian now. With todays cpus fast byteswap
instructions that's not an issue but the new variant keeps the code clean
and maintainable.

SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:29821a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2008-02-07 18:11:47 +11:00