Replace i_pin_wait, which is only used during synchronous inode flushing
with a bit waitqueue.  This trades off a much smaller inode against
slightly slower wakeup performance, and saves 12 (32-bit) or 20 (64-bit)
bytes in the XFS inode.
Reviewed-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

We almost never block on i_flock, the exception is synchronous inode
flushing.  Instead of bloating the inode with a 16/24-byte completion
that we abuse as a semaphore just implement it as a bitlock that uses
a bit waitqueue for the rare sleeping path.  This primarily is a
tradeoff between a much smaller inode and a faster non-blocking
path vs faster wakeups, and we are much better off with the former.

A small downside is that we will lose lockdep checking for i_flock, but
given that it's always taken inside the ilock that should be acceptable.

Note that for example the inode writeback locking is implemented in a
very similar way.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

To be used for bit wakeup i_flags needs to be an unsigned long or we'll
run into trouble on big endian systems.  Because of the 1-byte i_update
field right after it this actually causes a fairly large size increase
on its own (4 or 8 bytes), but that increase will be more than offset
by the next two patches.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

We spent a lot of effort to maintain this field, but it always equals to the
fork size divided by the constant size of an extent.  The prime use of it is
to assert that the two stay in sync.  Just divide the fork size by the extent
size in the few places that we actually use it and remove the overhead
of maintaining it.  Also introduce a few helpers to consolidate the places
where we actually care about the value.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

.. and the just as dead bhv_desc forward declaration while we're at it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

This wrapper isn't overly useful, not to say rather confusing.

Around the call to xfs_itruncate_extents it does:

 - add tracing
 - add a few asserts in debug builds
 - conditionally update the inode size in two places
 - log the inode

Both the tracing and the inode logging can be moved to xfs_itruncate_extents
as they are useful for the attribute fork as well - in fact the attr code
already does an equivalent xfs_trans_log_inode call just after calling
xfs_itruncate_extents.  The conditional size updates are a mess, and there
was no reason to do them in two places anyway, as the first one was
conditional on the inode having extents - but without extents we
xfs_itruncate_extents would be a no-op and the placement wouldn't matter
anyway.  Instead move the size assignments and the asserts that make sense
to the callers that want it.

As a side effect of this clean up xfs_setattr_size by introducing variables
for the old and new inode size, and moving the size updates into a common
place.
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

If we are doing synchronous inode reclaim we block the VM from making
progress in memory reclaim.  So if we encouter a flush locked inode
promote it in the delwri list and wake up xfsbufd to write it out now.
Without this we can get hangs of up to 30 seconds during workloads hitting
synchronous inode reclaim.

The scheme is copied from what we do for dquot reclaims.
Reported-by: NSimon Kirby <sim@hostway.ca>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NSimon Kirby <sim@hostway.ca>
Signed-off-by: NBen Myers <bpm@sgi.com>

We now have an i_dio_count filed and surrounding infrastructure to wait
for direct I/O completion instead of i_icount, and we have never needed
to iocount waits for buffered I/O given that we only set the page uptodate
after finishing all required work.  Thus remove i_iocount, and replace
the actually needed waits with calls to inode_dio_wait.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Remove the transaction pointer in the inode.  It's only used to avoid
passing down an argument in the bmap code, and for a few asserts in
the transaction code right now.

Also use the local variable ip in a few more places in xfs_inode_item_unlock,
so that it isn't only used for debug builds after the above change.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

Split the guts of xfs_itruncate_finish that loop over the existing extents
and calls xfs_bunmapi on them into a new helper, xfs_itruncate_externs.
Make xfs_attr_inactive call it directly instead of xfs_itruncate_finish,
which allows to simplify the latter a lot, by only letting it deal with
the data fork.  As a result xfs_itruncate_finish is renamed to
xfs_itruncate_data to make its use case more obvious.

Also remove the sync parameter from xfs_itruncate_data, which has been
unessecary since the introduction of the busy extent list in 2002, and
completely dead code since 2003 when the XFS_BMAPI_ASYNC parameter was
made a no-op.

I can't actually see why the xfs_attr_inactive needs to set the transaction
sync, but let's keep this patch simple and without changes in behaviour.

Also avoid passing a useless argument to xfs_isize_check, and make it
private to xfs_inode.c.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

xfs_itruncate_start is a rather length wrapper that evaluates to a call
to xfs_ioend_wait and xfs_tosspages, and only has two callers.

Instead of using the complicated checks left over from IRIX where we
can to truncate the pagecache just call xfs_tosspages
(aka truncate_inode_pages) directly as we want to get rid of all data
after i_size, and truncate_inode_pages handles incorrect alignments
and too large offsets just fine.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

XFS inodes has several per-lifetime state fields that determine the
behaviour of the inode. These state fields are not all reset when an
inode is reused from the reclaimable state.

This can lead to unexpected behaviour of the new inode such as
speculative preallocation not being truncated away in the expected
manner for local files until the inode is subsequently truncated,
freed or cycles out of the cache. It can also lead to an inode being
considered to be a filestream inode or having been truncated when
that is not the case.

Rework the reinitialisation of the inode when it is recycled to
ensure that it is pristine before it is reused. While there, also
fix the resetting of state flags in the recycling error paths so the
inode does not become unreclaimable.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

The if_lastex field in struct xfs_ifork is only used as a temporary
index during xfs_bmapi and xfs_bunmapi.  Instead of using the inode
fork to store it keep it local in the callchain.  Fortunately this
is very easy as we already pass a stack copy of it down the whole
chain which can simplify be changed to be passed by reference.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

The rt bitmap and summary inodes do not participate in the normal inode
locking protocol.  Instead the rt bitmap inode can be locked in any
transaction involving rt allocations, and the both of the rt inodes can
be locked at the same time.  Add specific lockdep subclasses for the rt
inodes to prevent lockdep from blowing up.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

A long standing problem for streaming writeѕ through the NFS server
has been that the NFS server opens and closes file descriptors on an
inode for every write. The result of this behaviour is that the
->release() function is called on every close and that results in
XFS truncating speculative preallocation beyond the EOF.  This has
an adverse effect on file layout when multiple files are being
written at the same time - they interleave their extents and can
result in severe fragmentation.

To avoid this problem, keep track of ->release calls made on a dirty
inode. For most cases, an inode is only going to be opened once for
writing and then closed again during it's lifetime in cache. Hence
if there are multiple ->release calls when the inode is dirty, there
is a good chance that the inode is being accessed by the NFS server.
Hence set a flag the first time ->release is called while there are
delalloc blocks still outstanding on the inode.

If this flag is set when ->release is next called, then do no
truncate away the speculative preallocation - leave it there so that
subsequent writes do not need to reallocate the delalloc space. This
will prevent interleaving of extents of different inodes written
concurrently to the same AG.

If we get this wrong, it is not a big deal as we truncate
speculative allocation beyond EOF anyway in xfs_inactive() when the
inode is thrown out of the cache.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

The XFS iolock needs to be re-initialised to a new lock class before
it enters reclaim to prevent lockdep false positives. Unfortunately,
this is not sufficient protection as inodes in the XFS_IRECLAIMABLE
state can be recycled and not re-initialised before being reused.

We need to re-initialise the lock state when transfering out of
XFS_IRECLAIMABLE state to XFS_INEW, but we need to keep the same
class as if the inode was just allocated. Hence we need a specific
lockdep class variable for the iolock so that both initialisations
use the same class.

While there, add a specific class for inodes in the reclaim state so
that it is easy to tell from lockdep reports what state the inode
was in that generated the report.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Clones an existing reference to inode; caller must already hold one.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch adds support for 32bit project quota identifiers.

On disk format is backward compatible with 16bit projid numbers. projid
on disk is now kept in two 16bit values - di_projid_lo (which holds the
same position as old 16bit projid value) and new di_projid_hi (takes
existing padding) and converts from/to 32bit value on the fly.

xfs_admin (for existing fs), mkfs.xfs (for new fs) needs to be used
to enable PROJID32BIT support.
Signed-off-by: NArkadiusz Miśkiewicz <arekm@maven.pl>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

We're not actually passing around credentials inside XFS for a while
now, so remove all xfs_cred.h with it's cred_t typedef and all
instances of it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Under heavy multi-way parallel create workloads, the VFS struggles
to write back all the inodes that have been changed in age order.
The bdi flusher thread becomes CPU bound, spending 85% of it's time
in the VFS code, mostly traversing the superblock dirty inode list
to separate dirty inodes old enough to flush.

We already keep an index of all metadata changes in age order - in
the AIL - and continued log pressure will do age ordered writeback
without any extra overhead at all. If there is no pressure on the
log, the xfssyncd will periodically write back metadata in ascending
disk address offset order so will be very efficient.

Hence we can stop marking VFS inodes dirty during transaction commit
or when changing timestamps during transactions. This will keep the
inodes in the superblock dirty list to those containing data or
unlogged metadata changes.

However, the timstamp changes are slightly more complex than this -
there are a couple of places that do unlogged updates of the
timestamps, and the VFS need to be informed of these. Hence add a
new function xfs_trans_ichgtime() for transactional changes,
and leave xfs_ichgtime() for the non-transactional changes.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

xfs_ireclaim has to get and put te pag structure because it is only
called with the inode to reclaim. The one caller of this function
already has a reference on the pag and a pointer to is, so move the
radix tree delete to the caller and remove xfs_ireclaim completely.
This avoids a xfs_perag_get/put on every inode being reclaimed.

The overhead was noticed in a bug report at:

https://bugzilla.kernel.org/show_bug.cgi?id=16348Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

xfs_iput is just a small wrapper for xfs_iunlock + IRELE.  Having this
out of line wrapper means the trace events in those two can't track
their caller properly.  So just remove the wrapper and opencode the
unlock + rele in the few callers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

We never get an i_mode of 0 or a locked VFS inode until we pass in the
XFS_IGET_CREATE flag to xfs_iget, which makes xfs_iput_new equivalent to
xfs_iput for the only caller.  In addition to that xfs_nfs_get_inode
does not even need to lock the inode given that the generation never changes
for a life inode, so just pass a 0 lock_flags to xfs_iget and release
the inode using IRELE in the error path.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

The block number comes from bulkstat based inode lookups to shortcut
the mapping calculations. We ar enot able to trust anything from
bulkstat, so drop the block number as well so that the correct
lookups and mappings are always done.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Inode numbers may come from somewhere external to the filesystem
(e.g. file handles, bulkstat information) and so are inherently
untrusted. Rename the flag we use for these lookups to make it
obvious we are doing a lookup of an untrusted inode number and need
to verify it completely before trying to read it from disk.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Inodes are only pinned/unpinned via the inode item methods, and lots of
code relies on that fact.  So remove the separate xfs_ipin/xfs_iunpin
helpers and merge them into their only callers.  This also fixes up
various duplicate and/or incorrect comments.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Allow us to track the difference between timestamp and size updates
by using mark_inode_dirty from the I/O completion code, and checking
the VFS inode flags in xfs_file_fsync.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.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>

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>

Change the xfs_iext_insert / xfs_iext_remove prototypes to pass more
information which will allow pushing the trace points from the callers
into those functions.  This includes folding the whichfork information
into the state variable to minimize the addition stack footprint.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

This is picking up on Felix's repost of Dave's patch to implement a
.dirty_inode method.  We really need this notification because
the VFS keeps writing directly into the inode structure instead
of going through methods to update this state.  In addition to
the long-known atime issue we now also have a caller in VM code
that updates c/mtime that way for shared writeable mmaps.  And
I found another one that no one has noticed in practice in the FIFO
code.

So implement ->dirty_inode to set i_update_core whenever the
inode gets externally dirtied, and switch the c/mtime handling to
the same scheme we already use for atime (always picking up
the value from the Linux inode).

Note that this patch also removes the xfs_synchronize_atime call
in xfs_reclaim it was superflous as we already synchronize the time
when writing the inode via the log (xfs_inode_item_format) or the
normal buffers (xfs_iflush_int).

In addition also remove the I_CLEAR check before copying the Linux
timestamps - now that we always have the Linux inode available
we can always use the timestamps in it.

Also switch to just using file_update_time for regular reads/writes -
that will get us all optimization done to it for free and make
sure we notice early when it breaks.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NAlex Elder <aelder@sgi.com>

xfs_trans_iget is a wrapper for xfs_iget that adds the inode to the
transaction after it is read.  Except when the inode already is in the
inode cache, in which case it returns the existing locked inode with
increment lock recursion counts.

Now, no one in the tree every decrements these lock recursion counts,
so any user of this gets a potential double unlock when both the original
owner of the inode and the xfs_trans_iget caller unlock it.  When looking
back in a git bisect in the historic XFS tree there was only one place
that decremented these counts, xfs_trans_iput.  Introduced in commit
ca25df7a840f426eb566d52667b6950b92bb84b5 by Adam Sweeney in 1993,
and removed in commit 19f899a3ab155ff6a49c0c79b06f2f61059afaf3 by
Steve Lord in 2003.  And as long as it didn't slip through git bisects
cracks never actually used in that time frame.

A quick audit of the callers of xfs_trans_iget shows that no caller
really relies on this behaviour fortunately - xfs_ialloc allows this
inode from disk so it must not be there before, and all the RT allocator
routines only every add each RT bitmap inode once.

In addition to removing lots of code and reducing the size of the inode
item this patch also avoids the double inode cache lookup in each
create/mkdir/mknod transaction.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAlex Elder <aelder@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

The guarantees for O_SYNC are exactly the same as the ones we need to
make for an fsync call (and given that Linux O_SYNC is O_DSYNC the
equivalent is fdadatasync, but we treat both the same in XFS), except
with a range data writeout.  Jan Kara has started unifying these two
path for filesystems using the generic helpers, and I've started to
look at XFS.

The actual transaction commited by xfs_fsync and xfs_write_sync_logforce
has a different transaction number, but actually is exactly the same.
We'll only use the fsync transaction going forward.  One major difference
is that xfs_write_sync_logforce never issues a cache flush unless we
commit a transaction causing that as a side-effect, which is an obvious
bug in the O_SYNC handling.  Second all the locking and i_update_size
vs i_update_core changes from 978b7237
never made it to xfs_write_sync_logforce, so we add them back.

To make xfs_fsync easily usable from the O_SYNC path, the filemap_fdatawait
call is moved up to xfs_file_fsync, so that we don't wait on the whole
file after we already waited for our portion in xfs_write.

We'll also use a plain call to filemap_write_and_wait_range instead
of the previous sync_page_rang which did it in two steps including
an half-hearted inode write out that doesn't help us.

Once we're done with this also remove the now useless i_update_size
tracking.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
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>

When freeing an inode that lost race getting added to the inode cache we
must not call into ->destroy_inode, because that would delete the inode
that won the race from the inode cache radix tree.

This patch uses splits a new xfs_inode_free helper out of xfs_ireclaim
and uses that plus __destroy_inode to make sure we really only free
the memory allocted for the inode that lost the race, and not mess with
the inode cache state.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>
Reported-by: NAlex Samad <alex@samad.com.au>
Reported-by: NAndrew Randrianasulu <randrik@mail.ru>
Reported-by: NStephane <sharnois@max-t.com>
Reported-by: NTommy <tommy@news-service.com>
Reported-by: NMiah Gregory <mace@darksilence.net>
Reported-by: NGabriel Barazer <gabriel@oxeva.fr>
Reported-by: NLeandro Lucarella <llucax@gmail.com>
Reported-by: NDaniel Burr <dburr@fami.com.au>
Reported-by: NNickolay <newmail@spaces.ru>
Reported-by: NMichael Guntsche <mike@it-loops.com>
Reported-by: NDan Carley <dan.carley+linuxkern-bugs@gmail.com>
Reported-by: NMichael Ole Olsen <gnu@gmx.net>
Reported-by: NMichael Weissenbacher <mw@dermichi.com>
Reported-by: NMartin Spott <Martin.Spott@mgras.net>
Reported-by: NChristian Kujau <lists@nerdbynature.de>
Tested-by: NMichael Guntsche <mike@it-loops.com>
Tested-by: NDan Carley <dan.carley+linuxkern-bugs@gmail.com>
Tested-by: NChristian Kujau <lists@nerdbynature.de>

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>