The rw parameter to direct_IO is redundant with iov_iter->type, and
treated slightly differently just about everywhere it's used: some users
do rw & WRITE, and others do rw == WRITE where they should be doing a
bitwise check. Simplify this with the new iov_iter_rw() helper, which
always returns either READ or WRITE.
Signed-off-by: NOmar Sandoval <osandov@osandov.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Most filesystems call through to these at some point, so we'll start
here.
Signed-off-by: NOmar Sandoval <osandov@osandov.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

struct kiocb now is a generic I/O container, so move it to fs.h.
Also do a #include diet for aio.h while we're at it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Back in the days when the direct I/O ->end_io callback could be called
from interrupt context for AIO we needed a structure to hand off to the
workqueue, and reused the ioend structure for this purpose.  These days
->end_io is always called from user or workqueue context, which allows us
to avoid this memory allocation and simplify the code significantly.

[dchinner: removed now unused xfs_finish_ioend_sync() function after
	   Brian Foster did an initial review. ]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

More on-disk format consolidation.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

More on-disk format consolidation.  A few declarations that weren't on-disk
format related move into better suitable spots.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

More consolidatation for the on-disk format defintions.  Note that the
XFS_IS_REALTIME_INODE moves to xfs_linux.h instead as it is not related
to the on disk format, but depends on a CONFIG_ option.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

xfs_vm_writepage() walks each buffer_head on the page, maps to the block
on disk and attaches to a running ioend structure that represents the
I/O submission. A new ioend is created when the type of I/O (unwritten,
delayed allocation or overwrite) required for a particular buffer_head
differs from the previous. If a buffer_head is a delalloc or unwritten
buffer, the associated bits are cleared by xfs_map_at_offset() once the
buffer_head is added to the ioend.

The process of mapping each buffer_head occurs in xfs_map_blocks() and
acquires the ilock in blocking or non-blocking mode, depending on the
type of writeback in progress. If the lock cannot be acquired for
non-blocking writeback, we cancel the ioend, redirty the page and
return. Writeback will revisit the page at some later point.

Note that we acquire the ilock for each buffer on the page. Therefore
during non-blocking writeback, it is possible to add an unwritten buffer
to the ioend, clear the unwritten state, fail to acquire the ilock when
mapping a subsequent buffer and cancel the ioend. If this occurs, the
unwritten status of the buffer sitting in the ioend has been lost. The
page will eventually hit writeback again, but xfs_vm_writepage() submits
overwrite I/O instead of unwritten I/O and does not perform unwritten
extent conversion at I/O completion. This leads to data corruption
because unwritten extents are treated as holes on reads and zeroes are
returned instead of reading from disk.

Modify xfs_cancel_ioend() to restore the buffer unwritten bit for ioends
of type XFS_IO_UNWRITTEN. This ensures that unwritten extent conversion
occurs once the page is eventually written back.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

XFS has been having trouble with stray delayed allocation extents
beyond EOF for a long time. Recent changes to the collapse range
code has triggered erroneous EBUSY errors on page invalidtion for
block size smaller than page size filesystems. These
have been caused by dirty buffers beyond EOF on a partial page which
do not get written to disk during a sync.

The issue is that write-ahead in xfs_cluster_write() finds such a
partial page and handles it by leaving the page dirty but pushing it
into a writeback state. This used to work just fine, as the
write_cache_pages() code would then find the dirty partial page in
the next mapping tree lookup as the dirty tag is still set.

Unfortunately, when we moved to a mark and sweep approach to
writeback to fix other writeback sync issues, we broken this. THe
act of marking the page as under writeback now clears the TOWRITE
tag in the radix tree, even though the page is still dirty. This
causes the TOWRITE tag to be cleared, and hence the next lookup on
the mapping tree does not find the dirty partial page and so doesn't
try to write it again.

This same writeback bug was found recently in ext4 and fixed in
commit 1c8349a1 ("ext4: fix data integrity sync in ordered mode")
without communication to the wider filesystem community. We can use
exactly the same fix here so the TOWRITE flag is not cleared on
partial page writes.

cc: stable@vger.kernel.org # dependent on 1c8349a1Root-cause-found-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

generic/263 is failing fsx at this point with a page spanning
EOF that cannot be invalidated. The operations are:

1190 mapwrite   0x52c00 thru    0x5e569 (0xb96a bytes)
1191 mapread    0x5c000 thru    0x5d636 (0x1637 bytes)
1192 write      0x5b600 thru    0x771ff (0x1bc00 bytes)

where 1190 extents EOF from 0x54000 to 0x5e569. When the direct IO
write attempts to invalidate the cached page over this range, it
fails with -EBUSY and so any attempt to do page invalidation fails.

The real question is this: Why can't that page be invalidated after
it has been written to disk and cleaned?

Well, there's data on the first two buffers in the page (1k block
size, 4k page), but the third buffer on the page (i.e. beyond EOF)
is failing drop_buffers because it's bh->b_state == 0x3, which is
BH_Uptodate | BH_Dirty.  IOWs, there's dirty buffers beyond EOF. Say
what?

OK, set_buffer_dirty() is called on all buffers from
__set_page_buffers_dirty(), regardless of whether the buffer is
beyond EOF or not, which means that when we get to ->writepage,
we have buffers marked dirty beyond EOF that we need to clean.
So, we need to implement our own .set_page_dirty method that
doesn't dirty buffers beyond EOF.

This is messy because the buffer code is not meant to be shared
and it has interesting locking issues on the buffer dirty bits.
So just copy and paste it and then modify it to suit what we need.

Note: the solutions the other filesystems and generic block code use
of marking the buffers clean in ->writepage does not work for XFS.
It still leaves dirty buffers beyond EOF and invalidations still
fail. Hence rather than play whack-a-mole, this patch simply
prevents those buffers from being dirtied in the first place.

cc: <stable@kernel.org>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Convert all the errors the core XFs code to negative error signs
like the rest of the kernel and remove all the sign conversion we
do in the interface layers.

Errors for conversion (and comparison) found via searches like:

$ git grep " E" fs/xfs
$ git grep "return E" fs/xfs
$ git grep " E[A-Z].*;$" fs/xfs

Negation points found via searches like:

$ git grep "= -[a-z,A-Z]" fs/xfs
$ git grep "return -[a-z,A-D,F-Z]" fs/xfs
$ git grep " -[a-z].*;" fs/xfs

[ with some bits I missed from Brian Foster ]
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

XFS_ERROR was designed long ago to trap return values, but it's not
runtime configurable, it's not consistently used, and we can do
similar error trapping with ftrace scripts and triggers from
userspace.

Just nuke XFS_ERROR and associated bits.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

I recently ran into the issue fixed by

  "xfs: kill buffers over failed write ranges properly"

which spams the log with lots of backtraces.  Make debugging any
issues like that easier by using WARN_ON_ONCE in the writeback code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Write to a file with an offset greater than 16TB on 32-bit system and
then trigger page write-back via sync(1) will cause task hang.

# block_size=4096
# offset=$(((2**32 - 1) * $block_size))
# xfs_io -f -c "pwrite $offset $block_size" /storage/test_file
# sync

INFO: task sync:2590 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
sync            D c1064a28     0  2590   2097 0x00000000
.....
Call Trace:
[<c1064a28>] ? ttwu_do_wakeup+0x18/0x130
[<c1066d0e>] ? try_to_wake_up+0x1ce/0x220
[<c1066dbf>] ? wake_up_process+0x1f/0x40
[<c104fc2e>] ? wake_up_worker+0x1e/0x30
[<c15b6083>] schedule+0x23/0x60
[<c15b3c2d>] schedule_timeout+0x18d/0x1f0
[<c12a143e>] ? do_raw_spin_unlock+0x4e/0x90
[<c10515f1>] ? __queue_delayed_work+0x91/0x150
[<c12a12ef>] ? do_raw_spin_lock+0x3f/0x100
[<c12a143e>] ? do_raw_spin_unlock+0x4e/0x90
[<c15b5b5d>] wait_for_completion+0x7d/0xc0
[<c1066d60>] ? try_to_wake_up+0x220/0x220
[<c116a4d2>] sync_inodes_sb+0x92/0x180
[<c116fb05>] sync_inodes_one_sb+0x15/0x20
[<c114a8f8>] iterate_supers+0xb8/0xc0
[<c116faf0>] ? fdatawrite_one_bdev+0x20/0x20
[<c116fc21>] sys_sync+0x31/0x80
[<c15be18d>] sysenter_do_call+0x12/0x28

This issue can be triggered via xfstests/generic/308.

The reason is that the end_index is unsigned long with maximum value
'2^32-1=4294967295' on 32-bit platform, and the given offset cause it
wrapped to 0, so that the following codes will repeat again and again
until the task schedule time out:

end_index = offset >> PAGE_CACHE_SHIFT;
last_index = (offset - 1) >> PAGE_CACHE_SHIFT;
if (page->index >= end_index) {
	unsigned offset_into_page = offset & (PAGE_CACHE_SIZE - 1);
        /*
         * Just skip the page if it is fully outside i_size, e.g. due
         * to a truncate operation that is in progress.
         */
        if (page->index >= end_index + 1 || offset_into_page == 0) {
	^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
		unlock_page(page);
		return 0;
	}

In order to check if a page is fully outsids i_size or not, we can fix
the code logic as below:
	if (page->index > end_index ||
	    (page->index == end_index && offset_into_page == 0))

Secondly, there still has another similar issue when calculating the
end offset for mapping the filesystem blocks to the file blocks for
delalloc.  With the same tests to above, run unmount(8) will cause
kernel panic if CONFIG_XFS_DEBUG is enabled:

XFS: Assertion failed: XFS_FORCED_SHUTDOWN(ip->i_mount) || \
	ip->i_delayed_blks == 0, file: fs/xfs/xfs_super.c, line: 964

kernel BUG at fs/xfs/xfs_message.c:108!
invalid opcode: 0000 [#1] SMP
task: edddc100 ti: ec6ee000 task.ti: ec6ee000
EIP: 0060:[<f83d87cb>] EFLAGS: 00010296 CPU: 1
EIP is at assfail+0x2b/0x30 [xfs]
..............
Call Trace:
[<f83d9cd4>] xfs_fs_destroy_inode+0x74/0x120 [xfs]
[<c115ddf1>] destroy_inode+0x31/0x50
[<c115deff>] evict+0xef/0x170
[<c115dfb2>] dispose_list+0x32/0x40
[<c115ea3a>] evict_inodes+0xca/0xe0
[<c1149706>] generic_shutdown_super+0x46/0xd0
[<c11497b9>] kill_block_super+0x29/0x70
[<c1149a14>] deactivate_locked_super+0x44/0x70
[<c114a427>] deactivate_super+0x47/0x60
[<c1161c3d>] mntput_no_expire+0xcd/0x120
[<c1162ae8>] SyS_umount+0xa8/0x370
[<c1162dce>] SyS_oldumount+0x1e/0x20
[<c15be18d>] sysenter_do_call+0x12/0x28

That because the end_offset is evaluated to 0 which is the same reason
to above, hence the mapping and covertion for dealloc file blocks to
file system blocks did not happened.

This patch just fixed both issues.
Reported-by: NMichael L. Semon <mlsemon35@gmail.com>
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

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

all callers have iov_length(iter->iov, iter->nr_segs) == iov_iter_count(iter)
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

Al Viro tracked down the problem that has caused generic/263 to fail
on XFS since the test was introduced. If is caused by
xfs_get_blocks() mapping a single extent that spans EOF without
marking it as buffer-new() so that the direct IO code does not zero
the tail of the block at the new EOF. This is a long standing bug
that has been around for many, many years.

Because xfs_get_blocks() starts the map before EOF, it can't set
buffer_new(), because that causes he direct IO code to also zero
unaligned sectors at the head of the IO. This would overwrite valid
data with zeros, and hence we cannot validly return a single extent
that spans EOF to direct IO.

Fix this by detecting a mapping that spans EOF and truncate it down
to EOF. This results in the the direct IO code doing the right thing
for unaligned data blocks before EOF, and then returning to get
another mapping for the region beyond EOF which XFS treats correctly
by setting buffer_new() on it. This makes direct Io behave correctly
w.r.t. tail block zeroing beyond EOF, and fsx is happy about that.

Again, thanks to Al Viro for finding what I couldn't.

[ dchinner: Fix for __divdi3 build error:
Reported-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Tested-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NMark Tinguely <tinguely@sgi.com>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
]
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Tested-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Similar to the write_begin problem, xfs-vm_write_end will truncate
back to the old EOF, potentially removing page cache from over the
top of delalloc blocks with valid data in them. Fix this by
truncating back to just the start of the failed write.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Tested-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <david@fromorbit.com>

If we fail a write beyond EOF and have to handle it in
xfs_vm_write_begin(), we truncate the inode back to the current inode
size. This doesn't take into account the fact that we may have
already made successful writes to the same page (in the case of block
size < page size) and hence we can truncate the page cache away from
blocks with valid data in them. If these blocks are delayed
allocation blocks, we now have a mismatch between the page cache and
the extent tree, and this will trigger - at minimum - a delayed
block count mismatch assert when the inode is evicted from the cache.
We can also trip over it when block mapping for direct IO - this is
the most common symptom seen from fsx and fsstress when run from
xfstests.

Fix it by only truncating away the exact range we are updating state
for in this write_begin call.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Tested-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <david@fromorbit.com>

When a write fails, if we don't clear the delalloc flags from the
buffers over the failed range, they can persist beyond EOF and cause
problems. writeback will see the pages in the page cache, see they
are dirty and continually retry the write, assuming that the page
beyond EOF is just racing with a truncate. The page will eventually
be released due to some other operation (e.g. direct IO), and it
will not pass through invalidation because it is dirty. Hence it
will be released with buffer_delay set on it, and trigger warnings
in xfs_vm_releasepage() and assert fail in xfs_file_aio_write_direct
because invalidation failed and we didn't write the corect amount.

This causes failures on block size < page size filesystems in fsx
and fsstress workloads run by xfstests.

Fix it by completely trashing any state on the buffer that could be
used to imply that it contains valid data when the delalloc range
over the buffer is punched out during the failed write handling.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Tested-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <david@fromorbit.com>

There were some extra semi-colons here which mean that we return true
unintentionally.

Fixes: a49935f2 ('xfs: xfs_check_page_type buffer checks need help')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

xfs_aops_discard_page() was introduced in the following commit:

  xfs: truncate delalloc extents when IO fails in writeback

... to clean up left over delalloc ranges after I/O failure in
->writepage(). generic/224 tests for this scenario and occasionally
reproduces panics on sub-4k blocksize filesystems.

The cause of this is failure to clean up the delalloc range on a
page where the first buffer does not match one of the expected
states of xfs_check_page_type(). If a buffer is not unwritten,
delayed or dirty&mapped, xfs_check_page_type() stops and
immediately returns 0.

The stress test of generic/224 creates a scenario where the first
several buffers of a page with delayed buffers are mapped & uptodate
and some subsequent buffer is delayed. If the ->writepage() happens
to fail for this page, xfs_aops_discard_page() incorrectly skips
the entire page.

This then causes later failures either when direct IO maps the range
and finds the stale delayed buffer, or we evict the inode and find
that the inode still has a delayed block reservation accounted to
it.

We can easily fix this xfs_aops_discard_page() failure by making
xfs_check_page_type() check all buffers, but this breaks
xfs_convert_page() more than it is already broken. Indeed,
xfs_convert_page() wants xfs_check_page_type() to tell it if the
first buffers on the pages are of a type that can be aggregated into
the contiguous IO that is already being built.

xfs_convert_page() should not be writing random buffers out of a
page, but the current behaviour will cause it to do so if there are
buffers that don't match the current specification on the page.
Hence for xfs_convert_page() we need to:

	a) return "not ok" if the first buffer on the page does not
	match the specification provided to we don't write anything;
	and
	b) abort it's buffer-add-to-io loop the moment we come
	across a buffer that does not match the specification.

Hence we need to fix both xfs_check_page_type() and
xfs_convert_page() to work correctly with pages that have mixed
buffer types, whilst allowing xfs_aops_discard_page() to scan all
buffers on the page for a type match.
Reported-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDave Chinner <david@fromorbit.com>

XFS can easily support appending aio writes by ensuring we always allocate
blocks as unwritten extents when performing direct I/O writes and only
converting them to written extents at I/O completion.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NDave Chinner <david@fromorbit.com>

Make it clear that we're only locking against the extent map on the data
fork.  Also clean the function up a little bit.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Immutable biovecs are going to require an explicit iterator. To
implement immutable bvecs, a later patch is going to add a bi_bvec_done
member to this struct; for now, this patch effectively just renames
things.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@inktank.com>
Cc: ceph-devel@vger.kernel.org
Cc: Joshua Morris <josh.h.morris@us.ibm.com>
Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Cc: Boaz Harrosh <bharrosh@panasas.com>
Cc: Benny Halevy <bhalevy@tonian.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Nicholas A. Bellinger" <nab@linux-iscsi.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Dave Kleikamp <shaggy@kernel.org>
Cc: Joern Engel <joern@logfs.org>
Cc: Prasad Joshi <prasadjoshi.linux@gmail.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Ben Myers <bpm@sgi.com>
Cc: xfs@oss.sgi.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Guo Chao <yan@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <Ian.Campbell@citrix.com>
Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Jerome Marchand <jmarchand@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: Peng Tao <tao.peng@emc.com>
Cc: Andy Adamson <andros@netapp.com>
Cc: fanchaoting <fanchaoting@cn.fujitsu.com>
Cc: Jie Liu <jeff.liu@oracle.com>
Cc: Sunil Mushran <sunil.mushran@gmail.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Namjae Jeon <namjae.jeon@samsung.com>
Cc: Pankaj Kumar <pankaj.km@samsung.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Cc: Mel Gorman <mgorman@suse.de>6

Page cache allocation doesn't always go through ->begin_write and
hence we don't always get the opportunity to set the allocation
context to GFP_NOFS. Failing to do this means we open up the direct
relcaim stack to recurse into the filesystem and consume a
significant amount of stack.

On RHEL6.4 kernels we are seeing ra_submit() and
generic_file_splice_read() from an nfsd context recursing into the
filesystem via the inode cache shrinker and evicting inodes. This is
causing truncation to be run (e.g EOF block freeing) and causing
bmap btree block merges and free space btree block splits to occur.
These btree manipulations are occurring with the call chain already
30 functions deep and hence there is not enough stack space to
complete such operations.

To avoid these specific overruns, we need to prevent the page cache
allocation from recursing via direct reclaim. We can do that because
the allocation functions take the allocation context from that which
is stored in the mapping for the inode. We don't set that right now,
so the default is GFP_HIGHUSER_MOVABLE, which is effectively a
GFP_KERNEL context. We need it to be the equivalent of GFP_NOFS, so
when we initialise an inode, set the mapping gfp mask appropriately.

This makes the use of AOP_FLAG_NOFS redundant from other parts of
the XFS IO path, so get rid of it.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

Currently the xfs_inode.h header has a dependency on the definition
of the BMAP btree records as the inode fork includes an array of
xfs_bmbt_rec_host_t objects in it's definition.

Move all the btree format definitions from xfs_btree.h,
xfs_bmap_btree.h, xfs_alloc_btree.h and xfs_ialloc_btree.h to
xfs_format.h to continue the process of centralising the on-disk
format definitions. With this done, the xfs inode definitions are no
longer dependent on btree header files.

The enables a massive culling of unnecessary includes, with close to
200 #include directives removed from the XFS kernel code base.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

xfs_trans.h has a dependency on xfs_log.h for a couple of
structures. Most code that does transactions doesn't need to know
anything about the log, but this dependency means that they have to
include xfs_log.h. Decouple the xfs_trans.h and xfs_log.h header
files and clean up the includes to be in dependency order.

In doing this, remove the direct include of xfs_trans_reserve.h from
xfs_trans.h so that we remove the dependency between xfs_trans.h and
xfs_mount.h. Hence the xfs_trans.h include can be moved to the
indicate the actual dependencies other header files have on it.

Note that these are kernel only header files, so this does not
translate to any userspace changes at all.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

All of the buffer operations structures are needed to be exported
for xfs_db, so move them all to a common location rather than
spreading them all over the place. They are verifying the on-disk
format, so while xfs_format.h might be a good place, it is not part
of the on disk format.

Hence we need to create a new header file that we centralise these
related definitions. Start by moving the bffer operations
structures, and then also move all the other definitions that have
crept into xfs_log_format.h and xfs_format.h as there was no other
shared header file to put them in.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

Get rid of function variable count from xfs_iomap_write_allocate() as
it is unused.

Additionally, checkpatch warn me of the following for this change:
WARNING: extern prototypes should be avoided in .h files
+extern int xfs_iomap_write_allocate(struct xfs_inode *, xfs_off_t,

So this patch also remove all extern function prototypes at xfs_iomap.h
to suppress it to make this code style in consistent manner in this file.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

truncate_pagecache() doesn't care about old size since commit
cedabed4 ("vfs: Fix vmtruncate() regression").  Let's drop it.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support to the core direct-io code to defer AIO completions to user
context using a workqueue.  This replaces opencoded and less efficient
code in XFS and ext4 (we save a memory allocation for each direct IO)
and will be needed to properly support O_(D)SYNC for AIO.

The communication between the filesystem and the direct I/O code requires
a new buffer head flag, which is a bit ugly but not avoidable until the
direct I/O code stops abusing the buffer_head structure for communicating
with the filesystems.

Currently this creates a per-superblock unbound workqueue for these
completions, which is taken from an earlier patch by Jan Kara.  I'm
not really convinced about this use and would prefer a "normal" global
workqueue with a high concurrency limit, but this needs further discussion.

JK: Fixed ext4 part, dynamic allocation of the workqueue.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Follow up with xfs naming style.
Signed-off-by: NZhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

With the new xfs_trans_res structure has been introduced, the log
reservation size, log count as well as log flags are pre-initialized
at mount time.  So it's time to refine xfs_trans_reserve() interface
to be more neat.

Also, introduce a new helper M_RES() to return a pointer to the
mp->m_resv structure to simplify the input.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Now we have xfs_inode.c for holding kernel-only XFS inode
operations, move all the inode operations from xfs_vnodeops.c to
this new file as it holds another set of kernel-only inode
operations. The name of this file traces back to the days of Irix
and it's vnodes which we don't have anymore.

Essentially this move consolidates the inode locking functions
and a bunch of XFS inode operations into the one file. Eventually
the high level functions will be merged into the VFS interface
functions in xfs_iops.c.

This leaves only internal preallocation, EOF block manipulation and
hole punching functions in vnodeops.c. Move these to xfs_bmap_util.c
where we are already consolidating various in-kernel physical extent
manipulation and querying functions.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

There is a bunch of code in xfs_bmap.c that is kernel specific and
not shared with userspace. To minimise the difference between the
kernel and userspace code, shift this unshared code to
xfs_bmap_util.c, and the declarations to xfs_bmap_util.h.

The biggest issue here is xfs_bmap_finish() - userspace has it's own
definition of this function, and so we need to move it out of
xfs_bmap.[ch]. This means several other files need to include
xfs_bmap_util.h as well.

It also introduces and interesting dance for the stack switching
code in xfs_bmapi_allocate(). The stack switching/workqueue code is
actually moved to xfs_bmap_util.c, so that userspace can simply use
a #define in a header file to connect the dots without needing to
know about the stack switch code at all.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

In xfs_vm_write_failed(), we evaluate the block_offset of pos with
PAGE_MASK which is an unsigned long.  That is fine on 64-bit platforms
regardless of whether the request pos is 32-bit or 64-bit.  However, on
32-bit platforms the value is 0xfffff000 and so the high 32 bits in it
will be masked off with (pos & PAGE_MASK) for a 64-bit pos.

As a result, the evaluated block_offset is incorrect which will cause
this failure ASSERT(block_offset + from == pos); and potentially pass
the wrong block to xfs_vm_kill_delalloc_range().

In this case, we can get a kernel panic if CONFIG_XFS_DEBUG is enabled:

XFS: Assertion failed: block_offset + from == pos, file: fs/xfs/xfs_aops.c, line: 1504

------------[ cut here ]------------
 kernel BUG at fs/xfs/xfs_message.c:100!
 invalid opcode: 0000 [#1] SMP
 ........
 Pid: 4057, comm: mkfs.xfs Tainted: G           O 3.9.0-rc2 #1
 EIP: 0060:[<f94a7e8b>] EFLAGS: 00010282 CPU: 0
 EIP is at assfail+0x2b/0x30 [xfs]
 EAX: 00000056 EBX: f6ef28a0 ECX: 00000007 EDX: f57d22a4
 ESI: 1c2fb000 EDI: 00000000 EBP: ea6b5d30 ESP: ea6b5d1c
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
 CR0: 8005003b CR2: 094f3ff4 CR3: 2bcb4000 CR4: 000006f0
 DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
 DR6: ffff0ff0 DR7: 00000400
 Process mkfs.xfs (pid: 4057, ti=ea6b4000 task=ea5799e0 task.ti=ea6b4000)
 Stack:
 00000000 f9525c48 f951fa80 f951f96b 000005e4 ea6b5d7c f9494b34 c19b0ea2
 00000066 f3d6c620 c19b0ea2 00000000 e9a91458 00001000 00000000 00000000
 00000000 c15c7e89 00000000 1c2fb000 00000000 00000000 1c2fb000 00000080
 Call Trace:
 [<f9494b34>] xfs_vm_write_failed+0x74/0x1b0 [xfs]
 [<c15c7e89>] ? printk+0x4d/0x4f
 [<f9494d7d>] xfs_vm_write_begin+0x10d/0x170 [xfs]
 [<c110a34c>] generic_file_buffered_write+0xdc/0x210
 [<f949b669>] xfs_file_buffered_aio_write+0xf9/0x190 [xfs]
 [<f949b7f3>] xfs_file_aio_write+0xf3/0x160 [xfs]
 [<c115e504>] do_sync_write+0x94/0xd0
 [<c115ed1f>] vfs_write+0x8f/0x160
 [<c115e470>] ? wait_on_retry_sync_kiocb+0x50/0x50
 [<c115f017>] sys_write+0x47/0x80
 [<c15d860d>] sysenter_do_call+0x12/0x28
 .............
 EIP: [<f94a7e8b>] assfail+0x2b/0x30 [xfs] SS:ESP 0068:ea6b5d1c
 ---[ end trace cdd9af4f4ecab42f ]---
 Kernel panic - not syncing: Fatal exception

In order to avoid this, we can evaluate the block_offset of the start
of the page by using shifts rather than masks the mismatch problem.

Thanks Dave Chinner for help finding and fixing this bug.
Reported-by: NMichael L. Semon <mlsemon35@gmail.com>
Reviewed-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

FSX on 512 byte block size filesystems has been failing for some
time with corrupted data. The fault dates back to the change in
the writeback data integrity algorithm that uses a mark-and-sweep
approach to avoid data writeback livelocks.

Unfortunately, a side effect of this mark-and-sweep approach is that
each page will only be written once for a data integrity sync, and
there is a condition in writeback in XFS where a page may require
two writeback attempts to be fully written. As a result of the high
level change, we now only get a partial page writeback during the
integrity sync because the first pass through writeback clears the
mark left on the page index to tell writeback that the page needs
writeback....

The cause is writing a partial page in the clustering code. This can
happen when a mapping boundary falls in the middle of a page - we
end up writing back the first part of the page that the mapping
covers, but then never revisit the page to have the remainder mapped
and written.

The fix is simple - if the mapping boundary falls inside a page,
then simple abort clustering without touching the page. This means
that the next ->writepage entry that write_cache_pages() will make
is the page we aborted on, and xfs_vm_writepage() will map all
sections of the page correctly. This behaviour is also optimal for
non-data integrity writes, as it results in contiguous sequential
writeback of the file rather than missing small holes and having to
write them a "random" writes in a future pass.

With this fix, all the fsx tests in xfstests now pass on a 512 byte
block size filesystem on a 4k page machine.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

(cherry picked from commit 49b137cb)

->invalidatepage() aop now accepts range to invalidate so we can make
use of it in xfs_vm_invalidatepage()
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Acked-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Cc: xfs@oss.sgi.com