Pass the full length to iomap_zero() and dax_iomap_zero(), and have
them return how many bytes they actually handled.  This is preparatory
work for handling THP, although it looks like DAX could actually take
advantage of it if there's a larger contiguous area.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

iomap_write_end cannot return an error, so switch it to return
size_t instead of int and remove the error checking from the callers.
Also convert the arguments to size_t from unsigned int, in case anyone
ever wants to support a page size larger than 2GB.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Instead of counting bio segments, count the number of bytes submitted.
This insulates us from the block layer's definition of what a 'same page'
is, which is not necessarily clear once THPs are involved.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Instead of counting bio segments, count the number of bytes submitted.
This insulates us from the block layer's definition of what a 'same page'
is, which is not necessarily clear once THPs are involved.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Size the uptodate array dynamically to support larger pages in the
page cache.  With a 64kB page, we're only saving 8 bytes per page today,
but with a 2MB maximum page size, we'd have to allocate more than 4kB
per page.  Add a few debugging assertions.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Now that the bitmap is protected by a spinlock, we can use the
more efficient bitmap ops instead of individual test/set bit ops.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

We can skip most of the initialisation, although spinlocks still
need explicit initialisation as architectures may use a non-zero
value to indicate unlocked.  The comment is no longer useful as
attach_page_private() handles the refcount now.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

This helper is useful for both THPs and for supporting block size larger
than page size.  Convert all users that I could find (we have a few
different ways of writing this idiom, and I may have missed some).
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Acked-by: NDave Kleikamp <dave.kleikamp@oracle.com>

If iomap_unshare_actor() unshares to an inline iomap, the page was
not being flushed.  block_write_end() and __iomap_write_end() already
contain flushes, so adding it to iomap_write_end_inline() seems like
the best place.  That means we can remove it from iomap_write_actor().
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

When bringing (portions of) a page uptodate, we were marking blocks that
were zeroed as being uptodate, but not blocks that were read from storage.

Like the previous commit, this problem was found with generic/127 and
a kernel which failed readahead I/Os.  This bug causes writes to be
silently lost when working with flaky storage.

Fixes: 9dc55f13 ("iomap: add support for sub-pagesize buffered I/O without buffer heads")
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

If we find a page in write_begin which is !Uptodate, we need
to clear any error on the page before starting to read data
into it.  This matches how filemap_fault(), do_read_cache_page()
and generic_file_buffered_read() handle PageError on !Uptodate pages.
When calling iomap_set_range_uptodate() in __iomap_write_begin(), blocks
were not being marked as uptodate.

This was found with generic/127 and a specially modified kernel which
would fail (some) readahead I/Os.  The test read some bytes in a prior
page which caused readahead to extend into page 0x34.  There was
a subsequent write to page 0x34, followed by a read to page 0x34.
Because the blocks were still marked as !Uptodate, the read caused all
blocks to be re-read, overwriting the write.  With this change, and the
next one, the bytes which were written are marked as being Uptodate, so
even though the page is still marked as !Uptodate, the blocks containing
the written data are not re-read from storage.

Fixes: 9dc55f13 ("iomap: add support for sub-pagesize buffered I/O without buffer heads")
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Widen the type used for counting the number of bytes unshared.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Since the new pair function is introduced, we can call them to clean the
code in iomap.
Signed-off-by: NGuoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Link: http://lkml.kernel.org/r/20200517214718.468-7-guoqing.jiang@cloud.ionos.comSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use the new readahead operation in iomap.  Convert XFS and ZoneFS to use
it.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-26-willy@infradead.orgSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Implement the new readahead aop and convert all callers (block_dev,
exfat, ext2, fat, gfs2, hpfs, isofs, jfs, nilfs2, ocfs2, omfs, qnx6,
reiserfs & udf).

The callers are all trivial except for GFS2 & OCFS2.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> # ocfs2
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> # ocfs2
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NJohn Hubbard <jhubbard@nvidia.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NWilliam Kucharski <william.kucharski@oracle.com>
Cc: Chao Yu <yuchao0@huawei.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Gao Xiang <gaoxiang25@huawei.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>
Link: http://lkml.kernel.org/r/20200414150233.24495-17-willy@infradead.orgSigned-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add a helper dax_ioamp_zero() to zero a range. This patch basically
merges __dax_zero_page_range() and iomap_dax_zero().
Suggested-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20200228163456.1587-7-vgoyal@redhat.comSigned-off-by: NDan Williams <dan.j.williams@intel.com>

bio_alloc() can fail when we use GFP_NORETRY.  If it does, allocate
a bio large enough for a single page like mpage_readpages() does.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The 'pgoff' displayed by the tracepoints wasn't a pgoff at all; it
was a byte offset from the start of the file.  We already emit that in
the form of the 'offset', so we can just remove pgoff.  That means we
can remove 'page' as an argument to the tracepoint, and rename this
type of tracepoint from being a page class to being a range class.

Fixes: 0b1b213f ("xfs: event tracing support")
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

The check in block_page_mkwrite that is meant to determine whether an
offset is within the inode size is off by one.  This bug has been copied
into iomap_page_mkwrite and several filesystems (ubifs, ext4, f2fs,
ceph).

Fix that by introducing a new page_mkwrite_check_truncate helper that
checks for truncate and computes the bytes in the page up to EOF.  Use
the helper in iomap.

NOTE from Darrick: The original patch fixed a number of filesystems, but
then there were merge conflicts with the f2fs for-next tree; a
subsequent re-submission of the patch had different btrfs changes with
no explanation; and Christoph complained that each per-fs fix should be
a separate patch.  In my view that's too much risk to take on, so I
decided to drop all the hunks except for iomap, since I've actually QA'd
XFS.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
[darrick: drop everything but the iomap parts]
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

This patch fixes the following KASAN report. The @ioend has been
freed by dio_put(), but the iomap_finish_ioend() still trys to access
its data.

[20563.631624] BUG: KASAN: use-after-free in iomap_finish_ioend+0x58c/0x5c0
[20563.638319] Read of size 8 at addr fffffc0c54a36928 by task kworker/123:2/22184

[20563.647107] CPU: 123 PID: 22184 Comm: kworker/123:2 Not tainted 5.4.0+ #1
[20563.653887] Hardware name: HPE Apollo 70             /C01_APACHE_MB         , BIOS L50_5.13_1.11 06/18/2019
[20563.664499] Workqueue: xfs-conv/sda5 xfs_end_io [xfs]
[20563.669547] Call trace:
[20563.671993]  dump_backtrace+0x0/0x370
[20563.675648]  show_stack+0x1c/0x28
[20563.678958]  dump_stack+0x138/0x1b0
[20563.682455]  print_address_description.isra.9+0x60/0x378
[20563.687759]  __kasan_report+0x1a4/0x2a8
[20563.691587]  kasan_report+0xc/0x18
[20563.694985]  __asan_report_load8_noabort+0x18/0x20
[20563.699769]  iomap_finish_ioend+0x58c/0x5c0
[20563.703944]  iomap_finish_ioends+0x110/0x270
[20563.708396]  xfs_end_ioend+0x168/0x598 [xfs]
[20563.712823]  xfs_end_io+0x1e0/0x2d0 [xfs]
[20563.716834]  process_one_work+0x7f0/0x1ac8
[20563.720922]  worker_thread+0x334/0xae0
[20563.724664]  kthread+0x2c4/0x348
[20563.727889]  ret_from_fork+0x10/0x18

[20563.732941] Allocated by task 83403:
[20563.736512]  save_stack+0x24/0xb0
[20563.739820]  __kasan_kmalloc.isra.9+0xc4/0xe0
[20563.744169]  kasan_slab_alloc+0x14/0x20
[20563.747998]  slab_post_alloc_hook+0x50/0xa8
[20563.752173]  kmem_cache_alloc+0x154/0x330
[20563.756185]  mempool_alloc_slab+0x20/0x28
[20563.760186]  mempool_alloc+0xf4/0x2a8
[20563.763845]  bio_alloc_bioset+0x2d0/0x448
[20563.767849]  iomap_writepage_map+0x4b8/0x1740
[20563.772198]  iomap_do_writepage+0x200/0x8d0
[20563.776380]  write_cache_pages+0x8a4/0xed8
[20563.780469]  iomap_writepages+0x4c/0xb0
[20563.784463]  xfs_vm_writepages+0xf8/0x148 [xfs]
[20563.788989]  do_writepages+0xc8/0x218
[20563.792658]  __writeback_single_inode+0x168/0x18f8
[20563.797441]  writeback_sb_inodes+0x370/0xd30
[20563.801703]  wb_writeback+0x2d4/0x1270
[20563.805446]  wb_workfn+0x344/0x1178
[20563.808928]  process_one_work+0x7f0/0x1ac8
[20563.813016]  worker_thread+0x334/0xae0
[20563.816757]  kthread+0x2c4/0x348
[20563.819979]  ret_from_fork+0x10/0x18

[20563.825028] Freed by task 22184:
[20563.828251]  save_stack+0x24/0xb0
[20563.831559]  __kasan_slab_free+0x10c/0x180
[20563.835648]  kasan_slab_free+0x10/0x18
[20563.839389]  slab_free_freelist_hook+0xb4/0x1c0
[20563.843912]  kmem_cache_free+0x8c/0x3e8
[20563.847745]  mempool_free_slab+0x20/0x28
[20563.851660]  mempool_free+0xd4/0x2f8
[20563.855231]  bio_free+0x33c/0x518
[20563.858537]  bio_put+0xb8/0x100
[20563.861672]  iomap_finish_ioend+0x168/0x5c0
[20563.865847]  iomap_finish_ioends+0x110/0x270
[20563.870328]  xfs_end_ioend+0x168/0x598 [xfs]
[20563.874751]  xfs_end_io+0x1e0/0x2d0 [xfs]
[20563.878755]  process_one_work+0x7f0/0x1ac8
[20563.882844]  worker_thread+0x334/0xae0
[20563.886584]  kthread+0x2c4/0x348
[20563.889804]  ret_from_fork+0x10/0x18

[20563.894855] The buggy address belongs to the object at fffffc0c54a36900
                which belongs to the cache bio-1 of size 248
[20563.906844] The buggy address is located 40 bytes inside of
                248-byte region [fffffc0c54a36900, fffffc0c54a369f8)
[20563.918485] The buggy address belongs to the page:
[20563.923269] page:ffffffff82f528c0 refcount:1 mapcount:0 mapping:fffffc8e4ba31900 index:0xfffffc0c54a33300
[20563.932832] raw: 17ffff8000000200 ffffffffa3060100 0000000700000007 fffffc8e4ba31900
[20563.940567] raw: fffffc0c54a33300 0000000080aa0042 00000001ffffffff 0000000000000000
[20563.948300] page dumped because: kasan: bad access detected

[20563.955345] Memory state around the buggy address:
[20563.960129]  fffffc0c54a36800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
[20563.967342]  fffffc0c54a36880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[20563.974554] >fffffc0c54a36900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[20563.981766]                                   ^
[20563.986288]  fffffc0c54a36980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
[20563.993501]  fffffc0c54a36a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[20564.000713] ==================================================================

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205703Signed-off-by: NZorro Lang <zlang@redhat.com>
Fixes: 9cd0ed63 ("iomap: enhance writeback error message")
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

bio completions can race when a page spans more than one file system
block.  Add a spinlock to synchronize marking the page uptodate.

Fixes: 9dc55f13 ("iomap: add support for sub-pagesize buffered I/O without buffer heads")
Reported-by: NJan Stancek <jstancek@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

On architectures where loff_t is wider than pgoff_t, the expression
((page->index + 1) << PAGE_SHIFT) can overflow.  Rewrite to use the page
offset, which we already compute here anyway.
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The srcmap is used to identify where the read is to be performed from.
It is passed to ->iomap_begin, which can fill it in if we need to read
data for partially written blocks from a different location than the
write target.  The srcmap is only supported for buffered writes so far.
Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com>
[hch: merged two patches, removed the IOMAP_F_COW flag, use iomap as
      srcmap if not set, adjust length down to srcmap end as well]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Acked-by: NGoldwyn Rodrigues <rgoldwyn@suse.com>

Use the existing iomap write_begin code to read the pages unshared
by iomap_file_unshare.  That avoids the extra ->readpage call and
extent tree lookup currently done by read_mapping_page.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

That keeps the function a little easier to understand, and easier to
modify for pending enhancements.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

xfs_file_dirty is used to unshare reflink blocks.  Rename the function
to xfs_file_unshare to better document that purpose, and skip iomaps
that are not shared and don't need zeroing.  This will allow to simplify
the caller.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

All callers pass AOP_FLAG_NOFS, so lift that flag to iomap_write_begin
to allow reusing the flags arguments for an internal flags namespace
soon.  Also remove the local index variable that is only used once.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NAllison Collins <allison.henderson@oracle.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

If we encounter an IO error during writeback, log the inode, offset, and
sector number of the failure, instead of forcing the user to do some
sort of reverse mapping to figure out which file is affected.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

No need to pass the full bio_vec.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Move the initialization of ia and ib to the declaration line and remove
a superflous else.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Now that all the writepage code is in the iomap code there is no
need to keep this structure public.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

And inline mapping should never mark the page dirty and thus never end up
in writepages.  Add a check for that condition and warn if it happens.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Take the xfs writeback code and move it to fs/iomap.  A new structure
with three methods is added as the abstraction from the generic writeback
code to the file system.  These methods are used to map blocks, submit an
ioend, and cancel a page that encountered an error before it was added to
an ioend.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
[darrick: rename ->submit_ioend to ->prepare_ioend to clarify what it
does]
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

Lift the xfs code for tracing address space operations to the iomap
layer.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

File systems like gfs2 don't support delayed allocations or unwritten
extents and thus allocate normal mapped blocks to fill holes.  To
cover the case of such file systems allocating new blocks to fill holes
also zero out mapped blocks with the new flag.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Move the buffered IO code into a separate file so that we can group
related functions in a single file instead of having a single enormous
source file.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Move the direct IO code into a separate file so that we can group
related functions in a single file instead of having a single enormous
source file.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Move the SEEK_HOLE/SEEK_DATA code into a separate file so that we can
group related functions in a single file instead of having a single
enormous source file.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>