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>

Remove the inode item pointer and ili_last_lsn checks in
__xfs_iunpin_wait as any pinned inode is guaranteed to have them
valid.  After this the xfs_iunpin_nowait case is nothing more than a
xfs_log_force_lsn, as we know that the caller has already checked
the pincount.

Make xfs_iunpin_nowait the new low-level routine just doing the log
force and rewrite xfs_iunpin_wait around it.
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>

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>

Convert the remaining direct lookups of the per ag structures to use
get/put accesses. Ensure that the loops across AGs and prior users
of the interface balance gets and puts correctly.
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>

When reclaiming stale inodes, we need to guarantee that inodes are
unpinned before returning with a "clean" status. If we don't we can
reclaim inodes that are pinned, leading to use after free in the
transaction subsystem as transactions complete.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

Because inodes remain in cache much longer than inode buffers do
under memory pressure, we can get the situation where we have
stale, dirty inodes being reclaimed but the backing storage has
been freed.  Hence we should never, ever flush XFS_ISTALE inodes
to disk as there is no guarantee that the backing buffer is in
cache and still marked stale when the flush occurs.
Signed-off-by: NDave Chinner <david@fromorbit.com>
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>

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>

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>

Ramon tested XFS with a modified version of fsfuzzer and hit a NULL
pointer dereference in __xfs_get_blocks due to the RT device target
pointer being NULL.

To fix this reject inode with the realtime bit set on a a filesystem
without an RT subvolume during inode read.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Reported-by: NRamon de Carvalho Valle <ramon@risesecurity.org>
Tested-by: NRamon de Carvalho Valle <ramon@risesecurity.org>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Ramon tested XFS with a modified version of fsfuzzer and hit a NULL
pointer dereference in __xfs_get_blocks due to the RT device target
pointer being NULL.

To fix this reject inode with the realtime bit set on a a filesystem
without an RT subvolume during inode read.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Reported-by: NRamon de Carvalho Valle <ramon@risesecurity.org>
Tested-by: NRamon de Carvalho Valle <ramon@risesecurity.org>
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>

This patch rips out the XFS ACL handling code and uses the generic
fs/posix_acl.c code instead.  The ondisk format is of course left
unchanged.

This also introduces the same ACL caching all other Linux filesystems do
by adding pointers to the acl and default acl in struct xfs_inode.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>

We had some systems crash with this stack:

[<a00000010000cb20>] ia64_leave_kernel+0x0/0x280
[<a00000021291ca00>] xfs_bmbt_get_startoff+0x0/0x20 [xfs]
[<a0000002129080b0>] xfs_bmap_last_offset+0x210/0x280 [xfs]
[<a00000021295b010>] xfs_file_last_byte+0x70/0x1a0 [xfs]
[<a00000021295b200>] xfs_itruncate_start+0xc0/0x1a0 [xfs]
[<a0000002129935f0>] xfs_inactive_free_eofblocks+0x290/0x460 [xfs]
[<a000000212998fb0>] xfs_release+0x1b0/0x240 [xfs]
[<a0000002129ad930>] xfs_file_release+0x70/0xa0 [xfs]
[<a000000100162ea0>] __fput+0x1a0/0x420
[<a000000100163160>] fput+0x40/0x60

The problem here is that xfs_file_last_byte() does not acquire the
inode lock and can therefore race with another thread that is modifying
the extext list.  While xfs_bmap_last_offset() is trying to lookup
what was the last extent some extents were merged and the extent list
shrunk so the index we lookup is now beyond the end of the extent list
and potentially in a freed buffer.
Signed-off-by: NLachlan McIlroy <lmcilroy@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

We had some systems crash with this stack:

[<a00000010000cb20>] ia64_leave_kernel+0x0/0x280
[<a00000021291ca00>] xfs_bmbt_get_startoff+0x0/0x20 [xfs]
[<a0000002129080b0>] xfs_bmap_last_offset+0x210/0x280 [xfs]
[<a00000021295b010>] xfs_file_last_byte+0x70/0x1a0 [xfs]
[<a00000021295b200>] xfs_itruncate_start+0xc0/0x1a0 [xfs]
[<a0000002129935f0>] xfs_inactive_free_eofblocks+0x290/0x460 [xfs]
[<a000000212998fb0>] xfs_release+0x1b0/0x240 [xfs]
[<a0000002129ad930>] xfs_file_release+0x70/0xa0 [xfs]
[<a000000100162ea0>] __fput+0x1a0/0x420
[<a000000100163160>] fput+0x40/0x60

The problem here is that xfs_file_last_byte() does not acquire the
inode lock and can therefore race with another thread that is modifying
the extext list.  While xfs_bmap_last_offset() is trying to lookup
what was the last extent some extents were merged and the extent list
shrunk so the index we lookup is now beyond the end of the extent list
and potentially in a freed buffer.
Signed-off-by: NLachlan McIlroy <lmcilroy@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Remove the last of the macros-defined-to-static-functions.
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Recently we have quite a few kerneloops reports about dereferencing a NULL
if_data in the attribute fork.  From looking over the code this can only
happen if we pass a 0 size argument to xfs_iformat_local.  This implies some
sort of corruption and in fact the only mailinglist report about this from
earlier this year was after a powerfail presumably on a system with write
cache and without barriers.

Add a quick sanity check for the attr fork size in xfs_iformat to catch
these early and without an oops.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>

Recently we have quite a few kerneloops reports about dereferencing a NULL
if_data in the attribute fork.  From looking over the code this can only
happen if we pass a 0 size argument to xfs_iformat_local.  This implies some
sort of corruption and in fact the only mailinglist report about this from
earlier this year was after a powerfail presumably on a system with write
cache and without barriers.

Add a quick sanity check for the attr fork size in xfs_iformat to catch
these early and without an oops.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>

Remove the last of the macros-defined-to-static-functions.
Signed-off-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

Code does nothing so remove it.
Reviewed-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

 - xfs_sb.h add the XFS_SB_VERSION2_PARENTBIT features2 that has been
   around in userspace for some time
 - xfs_inode.h: move a few things out of __KERNEL__ that are needed by
   userspace
 - xfs_mount.h: only include xfs_sync.h under __KERNEL__
 - xfs_inode.c: minor whitespace fixup.  I accidentaly changes this when
   importing this file for use by userspace.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

None of this code appears to be used anywhere so remove it.
Reviewed-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>

The whole machinery to wait on I/O completion is related to the I/O path
and should be there instead of in xfs_vnode.c.  Also give the functions
more descriptive names.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>

Merge xfs_iextract and xfs_idestroy into xfs_ireclaim as they are never
called individually.  Also rewrite most comments in this area as they
were severly out of date.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>

Allocate the inode in xfs_iget_cache_miss and pass it into xfs_iread.  This
simplifies the error handling and allows xfs_iread to be shared with userspace
which already uses these semantics.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>

Just pass down the XFS_IGET_* flags all the way down to xfs_imap instead
of translating them mid-way.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>

Most uses of struct xfs_imap are to map and inode to a buffer.  To avoid
copying around the inode location information we should just embedd a
strcut xfs_imap into the xfs_inode.  To make sure it doesn't bloat an
inode the im_len is changed to a ushort, which is fine as that's what
the users exepect anyway.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>

xfs_imap is the only caller of xfs_dilocate and doesn't add any significant
value.  Merge the two functions and document the various cases we have for
inode cluster lookup in the new xfs_imap.

Also remove the unused im_agblkno and im_ioffset fields from struct xfs_imap
while we're at it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>

We have removed the support for old-style inode items a while ago and
xlog_recover_do_inode_trans is now only called for XFS_LI_INODE items.
That means we can remove the call to xfs_imap there and with it the
XFS_IMAP_LOOKUP that is set by all other callers.  We can also mark
xfs_imap static now.

(First sent on October 21st)
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>

The only caller of xfs_itobp that doesn't have i_blkno setup is now
the initial inode read.  It needs access to the whole xfs_imap so using
xfs_inotobp is not an option.  Instead opencode the buffer lookup in
xfs_iread and kill all the functionality for the initial map from
xfs_itobp.

(First sent on October 21st)
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>

These names don't add any value at all over just using the numerical
values.

(First sent on October 9th)
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>

Now that we have a separate xfs_icdinode_t for the in-core inode which
gets logged there is no need anymore for the xfs_dinode vs xfs_dinode_core
split - the fact that part of the structure gets logged through the inode
log item and a small part not can better be described in a comment.

All sizeof operations on the dinode_core either really wanted the
icdinode and are switched to that one, or had already added the size
of the agi unlinked list pointer.  Later both will be replaced with
helpers once we get the larger CRC-enabled dinode.

Removing the data and attribute fork unions also has the advantage that
xfs_dinode.h doesn't need to pull in every header under the sun.

While we're at it also add some more comments describing the dinode
structure.

(First sent on October 7th)
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>

Add a helper to read the AGI header and perform basic verification.
Based on hunks from a larger patch from Dave Chinner.

(First sent on Juli 23rd)
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Signed-off-by: NNiv Sardi <xaiki@sgi.com>

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

It's possible to have outstanding xfs_ioend_t's queued when the file size
is zero. This can happen in the direct I/O path when a direct I/O write
fails due to ENOSPC. In this case the xfs_ioend_t will still be queued (ie
xfs_end_io_direct() does not know that the I/O failed so can't force the
xfs_ioend_t to be flushed synchronously).

When we truncate a file on unlink we don't know to wait for these
xfs_ioend_ts and we can have a use-after-free situation if the inode is
reclaimed before the xfs_ioend_t is finally processed.

As was suggested by Dave Chinner lets wait for all I/Os to complete when
truncating the file size to zero.

SGI-PV: 981668

SGI-Modid: xfs-linux-melb:xfs-kern:32216a
Signed-off-by: NLachlan McIlroy <lachlan@sgi.com>
Signed-off-by: NChristoph Hellwig <hch@infradead.org>