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

Currently there is no way to truncate partial page where the end
truncate point is not at the end of the page. This is because it was not
needed and the functionality was enough for file system truncate
operation to work properly. However more file systems now support punch
hole feature and it can benefit from mm supporting truncating page just
up to the certain point.

Specifically, with this functionality truncate_inode_pages_range() can
be changed so it supports truncating partial page at the end of the
range (currently it will BUG_ON() if 'end' is not at the end of the
page).

This commit changes the invalidatepage() address space operation
prototype to accept range to be invalidated and update all the instances
for it.

We also change the block_invalidatepage() in the same way and actually
make a use of the new length argument implementing range invalidation.

Actual file system implementations will follow except the file systems
where the changes are really simple and should not change the behaviour
in any way .Implementation for truncate_page_range() which will be able
to accept page unaligned ranges will follow as well.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.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>

Faster kernel compiles by way of fewer unnecessary includes.

[akpm@linux-foundation.org: fix fallout]
[akpm@linux-foundation.org: fix build]
Signed-off-by: NKent Overstreet <koverstreet@google.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When a dirty page is truncated from a file but reclaim gets to it before
truncate_inode_pages(), we hit WARN_ON(delalloc) in
xfs_vm_releasepage(). This is because reclaim tries to write the page,
xfs_vm_writepage() just bails out (leaving page clean) and thus reclaim
thinks it can continue and calls xfs_vm_releasepage() on page with dirty
buffers.

Fix the issue by redirtying the page in xfs_vm_writepage(). This makes
reclaim stop reclaiming the page and also logically it keeps page in a
more consistent state where page with dirty buffers has PageDirty set.
Signed-off-by: NJan Kara <jack@suse.cz>
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Running AIO is pinning inode in memory using file reference. Once AIO
is completed using aio_complete(), file reference is put and inode can
be freed from memory. So we have to be sure that calling aio_complete()
is the last thing we do with the inode.

CC: xfs@oss.sgi.com
CC: Ben Myers <bpm@sgi.com>
CC: stable@vger.kernel.org
Signed-off-by: NJan Kara <jack@suse.cz>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Running AIO is pinning inode in memory using file reference. Once AIO
is completed using aio_complete(), file reference is put and inode can
be freed from memory. So we have to be sure that calling aio_complete()
is the last thing we do with the inode.

CC: xfs@oss.sgi.com
CC: Ben Myers <bpm@sgi.com>
CC: stable@vger.kernel.org
Signed-off-by: NJan Kara <jack@suse.cz>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

The direct IO path can do a nested transaction reservation when
writing past the EOF. The first transaction is the append
transaction for setting the filesize at IO completion, but we can
also need a transaction for allocation of blocks. If the log is low
on space due to reservations and small log, the append transaction
can be granted after wating for space as the only active transaction
in the system. This then attempts a reservation for an allocation,
which there isn't space in the log for, and the reservation sleeps.
The result is that there is nothing left in the system to wake up
all the processes waiting for log space to come free.

The stack trace that shows this deadlock is relatively innocuous:

 xlog_grant_head_wait
 xlog_grant_head_check
 xfs_log_reserve
 xfs_trans_reserve
 xfs_iomap_write_direct
 __xfs_get_blocks
 xfs_get_blocks_direct
 do_blockdev_direct_IO
 __blockdev_direct_IO
 xfs_vm_direct_IO
 generic_file_direct_write
 xfs_file_dio_aio_writ
 xfs_file_aio_write
 do_sync_write
 vfs_write

This was discovered on a filesystem with a log of only 10MB, and a
log stripe unit of 256k whih increased the base reservations by
512k. Hence a allocation transaction requires 1.2MB of log space to
be available instead of only 260k, and so greatly increased the
chance that there wouldn't be enough log space available for the
nested transaction to succeed. The key to reproducing it is this
mkfs command:

mkfs.xfs -f -d agcount=16,su=256k,sw=12 -l su=256k,size=2560b $SCRATCH_DEV

The test case was a 1000 fsstress processes running with random
freeze and unfreezes every few seconds. Thanks to Eryu Guan
(eguan@redhat.com) for writing the test that found this on a system
with a somewhat unique default configuration....

cc: <stable@vger.kernel.org>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAndrew Dahl <adahl@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

When we shut down the filesystem, it might first be detected in
writeback when we are allocating a inode size transaction. This
happens after we have moved all the pages into the writeback state
and unlocked them. Unfortunately, if we fail to set up the
transaction we then abort writeback and try to invalidate the
current page. This then triggers are BUG() in block_invalidatepage()
because we are trying to invalidate an unlocked page.

Fixing this is a bit of a chicken and egg problem - we can't
allocate the transaction until we've clustered all the pages into
the IO and we know the size of it (i.e. whether the last block of
the IO is beyond the current EOF or not). However, we don't want to
hold pages locked for long periods of time, especially while we lock
other pages to cluster them into the write.

To fix this, we need to make a clear delineation in writeback where
errors can only be handled by IO completion processing. That is,
once we have marked a page for writeback and unlocked it, we have to
report errors via IO completion because we've already started the
IO. We may not have submitted any IO, but we've changed the page
state to indicate that it is under IO so we must now use the IO
completion path to report errors.

To do this, add an error field to xfs_submit_ioend() to pass it the
error that occurred during the building on the ioend chain. When
this is non-zero, mark each ioend with the error and call
xfs_finish_ioend() directly rather than building bios. This will
immediately push the ioends through completion processing with the
error that has occurred.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

It is a complex wrapper around VFS functions, but there are VFS
functions that provide exactly the same functionality. Call the VFS
functions directly and remove the unnecessary indirection and
complexity.

We don't need to care about clearing the XFS_ITRUNCATED flag, as
that is done during .writepages. Hence is cleared by the VFS
writeback path if there is anything to write back during the flush.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NAndrew Dahl <adahl@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

When we shut down the filesystem, it might first be detected in
writeback when we are allocating a inode size transaction. This
happens after we have moved all the pages into the writeback state
and unlocked them. Unfortunately, if we fail to set up the
transaction we then abort writeback and try to invalidate the
current page. This then triggers are BUG() in block_invalidatepage()
because we are trying to invalidate an unlocked page.

Fixing this is a bit of a chicken and egg problem - we can't
allocate the transaction until we've clustered all the pages into
the IO and we know the size of it (i.e. whether the last block of
the IO is beyond the current EOF or not). However, we don't want to
hold pages locked for long periods of time, especially while we lock
other pages to cluster them into the write.

To fix this, we need to make a clear delineation in writeback where
errors can only be handled by IO completion processing. That is,
once we have marked a page for writeback and unlocked it, we have to
report errors via IO completion because we've already started the
IO. We may not have submitted any IO, but we've changed the page
state to indicate that it is under IO so we must now use the IO
completion path to report errors.

To do this, add an error field to xfs_submit_ioend() to pass it the
error that occurred during the building on the ioend chain. When
this is non-zero, mark each ioend with the error and call
xfs_finish_ioend() directly rather than building bios. This will
immediately push the ioends through completion processing with the
error that has occurred.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

Generic code now blocks all writers from standard write paths. So we add
blocking of all writers coming from ioctl (we get a protection of ioctl against
racing remount read-only as a bonus) and convert xfs_file_aio_write() to a
non-racy freeze protection. We also keep freeze protection on transaction
start to block internal filesystem writes such as removal of preallocated
blocks.

CC: Ben Myers <bpm@sgi.com>
CC: Alex Elder <elder@kernel.org>
CC: xfs@oss.sgi.com
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add a XFS_ prefix to IO_DIRECT,XFS_IO_DELALLOC, XFS_IO_UNWRITTEN and
XFS_IO_OVERWRITE. This to avoid namespace conflict with other modules.
Signed-off-by: NAlain Renaud <arenaud@sgi.com>
Reviewed-by: NRich Johnston <rjohnston@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

We need to zero out part of a page which beyond EOF before setting uptodate,
otherwise, mapread or write will see non-zero data beyond EOF.

Based on the code in fs/buffer.c and the following ext4 commit:

  ext4: handle EOF correctly in ext4_bio_write_page()

And yes, I wish we had a good test case for it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

On filesytems with a block size smaller than PAGE_SIZE we currently have
a problem with unwritten extents.  If a we have multi-block page for
which an unwritten extent has been allocated, and only some of the
buffers have been written to, and they are not contiguous, we can expose
stale data from disk in the blocks between the writes after extent
conversion.

Example of a page with unwritten and real data.
buffer  content
0       empty  b_state = 0
1       DATA   b_state = 0x1023 Uptodate,Dirty,Mapped,Unwritten
2       DATA   b_state = 0x1023 Uptodate,Dirty,Mapped,Unwritten
3       empty  b_state = 0
4       empty  b_state = 0
5       DATA   b_state = 0x1023 Uptodate,Dirty,Mapped,Unwritten
6       DATA   b_state = 0x1023 Uptodate,Dirty,Mapped,Unwritten
7       empty  b_state = 0

Buffers 1, 2, 5, and 6 have been written to, leaving 0, 3, 4, and 7
empty.  Currently buffers 1, 2, 5, and 6 are added to a single ioend,
and when IO has completed, extent conversion creates a real extent from
block 1 through block 6, leaving 0 and 7 unwritten.  However buffers 3
and 4 were not written to disk, so stale data is exposed from those
blocks on a subsequent read.

Fix this by setting iomap_valid = 0 when we find a buffer that is not
Uptodate.  This ensures that buffers 5 and 6 are not added to the same
ioend as buffers 1 and 2.  Later these blocks will be converted into two
separate real extents, leaving the blocks in between unwritten.
Signed-off-by: NAlain Renaud <arenaud@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

The m_maxioffset field in the struct xfs_mount contains the same
value as the superblock s_maxbytes field. There is no need to carry
two copies of this limit around, so use the VFS superblock version.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

On filesytems with a block size smaller than PAGE_SIZE we currently have
a problem with unwritten extents.  If a we have multi-block page for
which an unwritten extent has been allocated, and only some of the
buffers have been written to, and they are not contiguous, we can expose
stale data from disk in the blocks between the writes after extent
conversion.

Example of a page with unwritten and real data.
buffer  content
0       empty  b_state = 0
1       DATA   b_state = 0x1023 Uptodate,Dirty,Mapped,Unwritten
2       DATA   b_state = 0x1023 Uptodate,Dirty,Mapped,Unwritten
3       empty  b_state = 0
4       empty  b_state = 0
5       DATA   b_state = 0x1023 Uptodate,Dirty,Mapped,Unwritten
6       DATA   b_state = 0x1023 Uptodate,Dirty,Mapped,Unwritten
7       empty  b_state = 0

Buffers 1, 2, 5, and 6 have been written to, leaving 0, 3, 4, and 7
empty.  Currently buffers 1, 2, 5, and 6 are added to a single ioend,
and when IO has completed, extent conversion creates a real extent from
block 1 through block 6, leaving 0 and 7 unwritten.  However buffers 3
and 4 were not written to disk, so stale data is exposed from those
blocks on a subsequent read.

Fix this by setting iomap_valid = 0 when we find a buffer that is not
Uptodate.  This ensures that buffers 5 and 6 are not added to the same
ioend as buffers 1 and 2.  Later these blocks will be converted into two
separate real extents, leaving the blocks in between unwritten.
Signed-off-by: NAlain Renaud <arenaud@sgi.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

With the removal of xfs_rw.h and other changes over time, xfs_bit.h
is being included in many files that don't actually need it. Clean
up the includes as necessary.

Also move the only-used-once xfs_ialloc_find_free() static inline
function out of a header file that is widely included to reduce
the number of needless dependencies on xfs_bit.h.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

The only thing left in xfs_rw.h is a function prototype for an inode
function.  Move that to xfs_inode.h, and kill xfs_rw.h.

Also move the function implementing the prototype from xfs_rw.c to
xfs_inode.c so we only have one function left in xfs_rw.c
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NBen Myers <bpm@sgi.com>

Untangle the header file includes a bit by moving the definition of
xfs_agino_t to xfs_types.h. This removes the dependency that xfs_ag.h has on
xfs_inum.h, meaning we don't need to include xfs_inum.h everywhere we include
xfs_ag.h.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NMark Tinguely <tinguely@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>