Currently we need to either call IHOLD or xfs_trans_ihold on an inode when
joining it to a transaction via xfs_trans_ijoin.

This patches instead makes xfs_trans_ijoin usable on it's own by doing
an implicity xfs_trans_ihold, which also allows us to drop the third
argument.  For the case where we want to hold a reference on the inode
a xfs_trans_ijoin_ref wrapper is added which does the IHOLD and marks
the inode for needing an xfs_iput.  In addition to the cleaner interface
to the caller this also simplifies the implementation.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>

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: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

https://bugzilla.kernel.org/show_bug.cgi?id=16348

When the filesystem grows to a large number of allocation groups,
the summing of recalimable inodes gets expensive. In many cases,
most AGs won't have any reclaimable inodes and so we are wasting CPU
time aggregating over these AGs. This is particularly important for
the inode shrinker that gets called frequently under memory
pressure.

To avoid the overhead, track AGs with reclaimable inodes in the
per-ag radix tree so that we can find all the AGs with reclaimable
inodes via a simple gang tag lookup. This involves setting the tag
when the first reclaimable inode is tracked in the AG, and removing
the tag when the last reclaimable inode is removed from the tree.
Then the summation process becomes a loop walking the radix tree
summing AGs with the reclaim tag set.

This significantly reduces the overhead of scanning - a 6400 AG
filesystea now only uses about 25% of a cpu in kswapd while slab
reclaim progresses instead of being permanently stuck at 100% CPU
and making little progress. Clean filesystems filesystems will see
no overhead and the overhead only increases linearly with the number
of dirty AGs.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Now the shrinker passes us a context, wire up a shrinker context per
filesystem. This allows us to remove the global mount list and the
locking problems that introduced. It also means that a shrinker call
does not need to traverse clean filesystems before finding a
filesystem with reclaimable inodes.  This significantly reduces
scanning overhead when lots of filesystems are present.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

The current shrinker implementation requires the registered callback
to have global state to work from. This makes it difficult to shrink
caches that are not global (e.g. per-filesystem caches). Pass the shrinker
structure to the callback so that users can embed the shrinker structure
in the context the shrinker needs to operate on and get back to it in the
callback via container_of().
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

If a filesystem is mounted without the inode64 mount option we
should still be able to access inodes not fitting into 32 bits, just
not created new ones.  For this to work we need to make sure the
inode cache radix tree is initialized for all allocation groups, not
just those we plan to allocate inodes from.  This patch makes sure
we initialize the inode cache radix tree for all allocation groups,
and also cleans xfs_initialize_perag up a bit to separate the
inode32 logical from the general perag structure setup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

xfs_bwrite is used with the intention of synchronously writing out
buffers, but currently it does not actually clear the async flag if
that's left from previous writes but instead implements async
behaviour if it finds it.  Remove the code handling asynchronous
writes as we've got rid of those entirely outside of the log and
delwri buffers, and make sure that we clear the async and read flags
before writing the buffer.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

All modifications to the superblock are done transactional through
xfs_trans_log_buf, so there is no reason to initiate periodic
asynchronous writeback.  This only removes the superblock from the
delwri list and will lead to sub-optimal I/O scheduling.

Cut down xfs_sync_fsdata now that it's only used for synchronous
superblock writes and move the log coverage checks into the two
callers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

This allows to see in `ps` and similar tools which kthreads are
allotted to which block device/filesystem, similar to what jbd2
does. As the process name is a fixed 16-char array, no extra
space is needed in tasks.

  PID TTY      STAT   TIME COMMAND
    2 ?        S      0:00 [kthreadd]
  197 ?        S      0:00  \_ [jbd2/sda2-8]
  198 ?        S      0:00  \_ [ext4-dio-unwrit]
  204 ?        S      0:00  \_ [flush-8:0]
 2647 ?        S      0:00  \_ [xfs_mru_cache]
 2648 ?        S      0:00  \_ [xfslogd/0]
 2649 ?        S      0:00  \_ [xfsdatad/0]
 2650 ?        S      0:00  \_ [xfsconvertd/0]
 2651 ?        S      0:00  \_ [xfsbufd/ram0]
 2652 ?        S      0:00  \_ [xfsaild/ram0]
 2653 ?        S      0:00  \_ [xfssyncd/ram0]
Signed-off-by: NJan Engelhardt <jengelh@medozas.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>

On low memory boxes or those with highmem, kernel can OOM before the
background reclaims inodes via xfssyncd. Add a shrinker to run inode
reclaim so that it inode reclaim is expedited when memory is low.

This is more complex than it needs to be because the VM folk don't
want a context added to the shrinker infrastructure. Hence we need
to add a global list of XFS mount structures so the shrinker can
traverse them.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Any inode reclaim flush that returns EAGAIN will result in the inode
reclaim being attempted again later. There is no need to issue a
warning into the logs about this situation.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

xfssyncd processes a queue of work by detaching the queue and
then iterating over all the work items. It then sleeps for a
time period or until new work comes in. If new work is queued
while xfssyncd is actively processing the detached work queue,
it will not process that new work until after a sleep timeout
or the next work event queued wakes it.

Fix this by checking the work queue again before going to sleep.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

The radix-tree code requires it's users to serialize tag updates
against other updates to the tree.  While XFS protects tag updates
against each other it does not serialize them against updates of the
tree contents, which can lead to tag corruption.  Fix the inode
cache to always take pag_ici_lock in exclusive mode when updating
radix tree tags.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reported-by: NPatrick Schreurs <patrick@news-service.com>
Tested-by: NPatrick Schreurs <patrick@news-service.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

We currently do background inode flush asynchronously, resulting in
inodes being written in whatever order the background writeback
issues them. Not only that, there are also blocking and non-blocking
asynchronous inode flushes, depending on where the flush comes from.

This patch completely removes asynchronous inode writeback. It
removes all the strange writeback modes and replaces them with
either a synchronous flush or a non-blocking delayed write flush.
That is, inode flushes will only issue IO directly if they are
synchronous, and background flushing may do nothing if the operation
would block (e.g. on a pinned inode or buffer lock).

Delayed write flushes will now result in the inode buffer sitting in
the delwri queue of the buffer cache to be flushed by either an AIL
push or by the xfsbufd timing out the buffer. This will allow
accumulation of dirty inode buffers in memory and allow optimisation
of inode cluster writeback at the xfsbufd level where we have much
greater queue depths than the block layer elevators. We will also
get adjacent inode cluster buffer IO merging for free when a later
patch in the series allows sorting of the delayed write buffers
before dispatch.

This effectively means that any inode that is written back by
background writeback will be seen as flush locked during AIL
pushing, and will result in the buffers being pushed from there.
This writeback path is currently non-optimal, but the next patch
in the series will fix that problem.

A side effect of this delayed write mechanism is that background
inode reclaim will no longer directly flush inodes, nor can it wait
on the flush lock. The result is that inode reclaim must leave the
inode in the reclaimable state until it is clean. Hence attempts to
reclaim a dirty inode in the background will simply skip the inode
until it is clean and this allows other mechanisms (i.e. xfsbufd) to
do more optimal writeback of the dirty buffers. As a result, the
inode reclaim code has been rewritten so that it no longer relies on
the ambiguous return values of xfs_iflush() to determine whether it
is safe to reclaim an inode.

Portions of this patch are derived from patches by Christoph
Hellwig.

Version 2:
- cleanup reclaim code as suggested by Christoph
- log background reclaim inode flush errors
- just pass sync flags to xfs_iflush
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

A.K.A.: don't rely on xfs_iflush() return value in reclaim

We have gradually been moving checks out of the reclaim code because
they are duplicated in xfs_iflush(). We've had a history of problems
in this area, and many of them stem from the overloading of the
return values from xfs_iflush() and interaction with inode flush
locking to determine if the inode is safe to reclaim.

With the desire to move to delayed write flushing of inodes and
non-blocking inode tree reclaim walks, the overloading of the
return value of xfs_iflush makes it very difficult to determine
the correct thing to do next.

This patch explicitly re-adds the checks to the inode reclaim code,
removing the reliance on the return value of xfs_iflush() to
determine what to do next. It also means that we can clearly
document all the inode states that reclaim must handle and hence
we can easily see that we handled all the necessary cases.

This also removes the need for the xfs_inode_clean() check in
xfs_iflush() as all callers now check this first (safely).
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Currently we define aliases for the buffer flags in various
namespaces, which only adds confusion.  Remove all but the XBF_
flags to clean this up a bit.

Note that we still abuse XFS_B_ASYNC/XBF_ASYNC for some non-buffer
uses, but I'll clean that up later.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

The filestreams cache flush is not needed in the sync code as it
does not affect data writeback, and it is now not used by the growfs
code, either, so kill it.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

xfs_get_perag is really getting the perag that an inode belongs to
based on it's inode number. Convert the use of this function to just
get the perag from a provided ag number.  Use this new function to
obtain the per-ag structure when traversing the per AG inode trees
for sync and reclaim.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Just minor housekeeping, a lot more functions can be trivially made
static; others could if we reordered things a bit...
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Signed-off-by: NAlex Elder <aelder@sgi.com>

The reclaim code will handle flushing of dirty inodes before reclaim
occurs, so avoid them when determining whether an inode is a
candidate for flushing to disk when walking the radix trees.  This
is based on a test patch from Christoph Hellwig.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Make the inode tree reclaim walk exclusive to avoid races with
concurrent sync walkers and lookups. This is a version of a patch
posted by Christoph Hellwig that avoids all the code duplication.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Currently the reclaim code for the case where we don't reclaim the
final reclaim is overly complicated.  We know that the inode is clean
but instead of just directly reclaiming the clean inode we go through
the whole process of marking the inode reclaimable just to directly
reclaim it from the calling context.  Besides being overly complicated
this introduces a race where iget could recycle an inode between
marked reclaimable and actually being reclaimed leading to panics.

This patch gets rid of the existing reclaim path, and replaces it with
a simple call to xfs_ireclaim if the inode was clean.  While we're at
it we also use the slightly more lax xfs_inode_clean check we'd use
later to determine if we need to flush the inode here.

Finally get rid of xfs_reclaim function and place the remaining small
bits of reclaim code directly into xfs_fs_destroy_inode.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reported-by: NPatrick Schreurs <patrick@news-service.com>
Reported-by: NTommy van Leeuwen <tommy@news-service.com>
Tested-by: NPatrick Schreurs <patrick@news-service.com>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

We want to always cover the log after writing out the superblock, and
in case of a synchronous writeout make sure we actually wait for the
log to be covered.  That way a filesystem that has been sync()ed can
be considered clean by log recovery.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

We need to do a synchronous xfs_sync_fsdata to make sure the superblock
actually is on disk when we return.

Also remove SYNC_BDFLUSH flag to xfs_sync_inodes because that particular
flag is never checked.

Move xfs_filestream_flush call later to only release inodes after they
have been written out.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

A lot more functions could be made static, but they need
forward declarations; this does some easy ones, and also
found a few unused functions in the process.
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

The locking in xfs_iget_cache_hit currently has numerous problems:

 - we clear the reclaim tag without i_flags_lock which protects
   modifications to it
 - we call inode_init_always which can sleep with pag_ici_lock
   held (this is oss.sgi.com BZ #819)
 - we acquire and drop i_flags_lock a lot and thus provide no
   consistency between the various flags we set/clear under it

This patch fixes all that with a major revamp of the locking in
the function.  The new version acquires i_flags_lock early and
only drops it once we need to call into inode_init_always or before
calling xfs_ilock.

This patch fixes a bug seen in the wild where we race modifying the
reclaim tag.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

The locking in xfs_iget_cache_hit currently has numerous problems:

 - we clear the reclaim tag without i_flags_lock which protects
   modifications to it
 - we call inode_init_always which can sleep with pag_ici_lock
   held (this is oss.sgi.com BZ #819)
 - we acquire and drop i_flags_lock a lot and thus provide no
   consistency between the various flags we set/clear under it

This patch fixes all that with a major revamp of the locking in
the function.  The new version acquires i_flags_lock early and
only drops it once we need to call into inode_init_always or before
calling xfs_ilock.

This patch fixes a bug seen in the wild where we race modifying the
reclaim tag.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

A lot more functions could be made static, but they need
forward declarations; this does some easy ones, and also
found a few unused functions in the process.
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

SYNC_BDFLUSH is a leftover from IRIX and rather misnamed for todays
code.  Make xfs_sync_fsdata and xfs_dq_sync use the SYNC_TRYLOCK flag
for not blocking on logs just as the inode sync code already does.

For xfs_sync_fsdata it's a trivial 1:1 replacement, but for xfs_qm_sync
I use the opportunity to decouple the non-blocking lock case from the
different flushing modes, similar to the inode sync code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>

We want to wait for all I/O to finish when we do data integrity syncs.  So
there is no reason to keep SYNC_WAIT separate from SYNC_IOWAIT.  This
causes a little change in behaviour for the ENOSPC flushing code which now
does a second submission and wait of buffered I/O, but that should finish
ASAP as we already did an asynchronous writeout earlier.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJosef 'Jeff' Sipek <jeffpc@josefsipek.net>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>

xfs_sync_inodes is used to write back either file data or inode metadata.
In general we always do these separately, except for one fishy case in
xfs_fs_put_super that does both.  So separate xfs_sync_inodes into
separate xfs_sync_data and xfs_sync_attr functions.  In xfs_fs_put_super
we first call the data sync and then the attr sync as that was the previous
order.  The moved log force in that path doesn't make a difference because
we will force the log again as part of the real unmount process.

The filesystem readonly checks are not performed by the new function but
instead moved into the callers, given that most callers alredy have it
further up in the stack.  Also add debug checks that we do not pass in
incorrect flags in the new xfs_sync_data and xfs_sync_attr function and
fix the one place that did pass in a wrong flag.

Also remove a comment mentioning xfs_sync_inodes that has been incorrect
for a while because we always take either the iolock or ilock in the
sync path these days.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>

Use xfs_inode_ag_iterator instead of opencoding the inode walk in the
quota code.  Mark xfs_inode_ag_iterator and xfs_sync_inode_valid non-static
to allow using them from the quota code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJosef 'Jeff' Sipek <jeffpc@josefsipek.net>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>

Given that we walk across the per-ag inode lists so often, it makes sense to
introduce an iterator for this.

Convert the sync and reclaim code to use this new iterator, quota code will
follow in the next patch.

Also change xfs_reclaim_inode to return -EGAIN instead of 1 for an inode
already under reclaim.  This simplifies the AG iterator and doesn't
matter for the only other caller.

[hch: merged the lookup and execute callbacks back into one to get the
 pag_ici_lock locking correct and simplify the code flow]
Signed-off-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>

The noblock parameter of xfs_reclaim_inodes is only ever set to zero. Remove
it and all the conditional code that is never executed.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>

Separate the validation of inodes found by the radix
tree walk from the radix tree lookup.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>

In many cases we only want to sync inode metadata. Split out the inode
flushing into a separate helper to prepare factoring the inode sync code.

Based on a patch from Dave Chinner, but redone to keep the current behaviour
exactly and leave changes to the flushing logic to another patch.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>

In many cases we only want to sync inode data. Start spliting the inode sync
into data sync and inode sync by factoring out the inode data flush.

[hch: minor cleanups]
Signed-off-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>