linux-toradex.git/fs/iomap.c, branch v4.9.123

iomap: fix integer truncation issues in the zeroing and dirtying helpers

2017-09-20T06:19:59+00:00

commit e28ae8e428fefe2facd72cea9f29906ecb9c861d upstream.

Fix the min_t calls in the zeroing and dirtying helpers to perform the
comparisms on 64-bit types, which prevents them from incorrectly
being truncated, and larger zeroing operations being stuck in a never
ending loop.

Special thanks to Markus Stockhausen for spotting the bug.

Reported-by: Paul Menzel 
Tested-by: Paul Menzel 
Signed-off-by: Christoph Hellwig 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong 
Signed-off-by: Greg Kroah-Hartman

fs: add i_blocksize()

2017-06-14T13:06:00+00:00

commit 93407472a21b82f39c955ea7787e5bc7da100642 upstream.

Replace all 1 << inode->i_blkbits and (1 << inode->i_blkbits) in fs
branch.

This patch also fixes multiple checkpatch warnings: WARNING: Prefer
'unsigned int' to bare use of 'unsigned'

Thanks to Andrew Morton for suggesting more appropriate function instead
of macro.

[geliangtang@gmail.com: truncate: use i_blocksize()]
  Link: http://lkml.kernel.org/r/9c8b2cd83c8f5653805d43debde9fa8817e02fc4.1484895804.git.geliangtang@gmail.com
Link: http://lkml.kernel.org/r/1481319905-10126-1-git-send-email-fabf@skynet.be
Signed-off-by: Fabian Frederick 
Signed-off-by: Geliang Tang 
Cc: Alexander Viro 
Cc: Ross Zwisler 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

fs: break out of iomap_file_buffered_write on fatal signals

2017-02-09T07:08:31+00:00

commit d1908f52557b3230fbd63c0429f3b4b748bf2b6d upstream.

Tetsuo has noticed that an OOM stress test which performs large write
requests can cause the full memory reserves depletion.  He has tracked
this down to the following path

	__alloc_pages_nodemask+0x436/0x4d0
	alloc_pages_current+0x97/0x1b0
	__page_cache_alloc+0x15d/0x1a0          mm/filemap.c:728
	pagecache_get_page+0x5a/0x2b0           mm/filemap.c:1331
	grab_cache_page_write_begin+0x23/0x40   mm/filemap.c:2773
	iomap_write_begin+0x50/0xd0             fs/iomap.c:118
	iomap_write_actor+0xb5/0x1a0            fs/iomap.c:190
	? iomap_write_end+0x80/0x80             fs/iomap.c:150
	iomap_apply+0xb3/0x130                  fs/iomap.c:79
	iomap_file_buffered_write+0x68/0xa0     fs/iomap.c:243
	? iomap_write_end+0x80/0x80
	xfs_file_buffered_aio_write+0x132/0x390 [xfs]
	? remove_wait_queue+0x59/0x60
	xfs_file_write_iter+0x90/0x130 [xfs]
	__vfs_write+0xe5/0x140
	vfs_write+0xc7/0x1f0
	? syscall_trace_enter+0x1d0/0x380
	SyS_write+0x58/0xc0
	do_syscall_64+0x6c/0x200
	entry_SYSCALL64_slow_path+0x25/0x25

the oom victim has access to all memory reserves to make a forward
progress to exit easier.  But iomap_file_buffered_write and other
callers of iomap_apply loop to complete the full request.  We need to
check for fatal signals and back off with a short write instead.

As the iomap_apply delegates all the work down to the actor we have to
hook into those.  All callers that work with the page cache are calling
iomap_write_begin so we will check for signals there.  dax_iomap_actor
has to handle the situation explicitly because it copies data to the
userspace directly.  Other callers like iomap_page_mkwrite work on a
single page or iomap_fiemap_actor do not allocate memory based on the
given len.

Fixes: 68a9f5e7007c ("xfs: implement iomap based buffered write path")
Link: http://lkml.kernel.org/r/20170201092706.9966-2-mhocko@kernel.org
Signed-off-by: Michal Hocko 
Reported-by: Tetsuo Handa 
Reviewed-by: Christoph Hellwig 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

fs: Do to trim high file position bits in iomap_page_mkwrite_actor

2016-10-24T03:20:25+00:00

iomap_page_mkwrite_actor() calls __block_write_begin_int() with position
masked as pos & ~PAGE_MASK which is equivalent to pos & (PAGE_SIZE-1).
Thus it masks off high bits of file position. However
__block_write_begin_int() expects full file position on input. This does
not cause any visible issues because all __block_write_begin_int()
really cares about are low file position bits but still it is a bug
waiting to happen.

Signed-off-by: Jan Kara 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Dave Chinner

iomap: add IOMAP_REPORT

2016-10-20T04:51:28+00:00

This allows the file system to tell a FIEMAP from a read operation, and thus
avoids the need to report flags that aren't actually used in the read path.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Darrick J. Wong 
Reviewed-by: Brian Foster 
Signed-off-by: Dave Chinner

Merge branch 'iomap-4.9-dax' into for-next

2016-10-02T22:53:59+00:00

iomap: expose iomap_apply outside iomap.c

2016-09-19T01:24:49+00:00

This allows the DAX code to use it.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Ross Zwisler 
Signed-off-by: Dave Chinner

iomap: add a flag to report shared extents

2016-09-19T00:13:02+00:00

Signed-off-by: Darrick J. Wong 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Dave Chinner

fs: add iomap_file_dirty

2016-09-19T00:12:45+00:00

Originally-From: Christoph Hellwig 

This function uses the iomap infrastructure to re-write all pages
in a given range.  This is useful for doing a copy-up of COW ranges,
and might be useful for scrubbing in the future.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Dave Chinner 
Signed-off-by: Dave Chinner

iomap: don't set FIEMAP_EXTENT_MERGED for extent based filesystems

2016-08-29T01:33:58+00:00

Filesystems like XFS that use extents should not set the
FIEMAP_EXTENT_MERGED flag in the fiemap extent structures.  To allow
for both behaviors for the upcoming gfs2 usage split the iomap
type field into type and flags, and only set FIEMAP_EXTENT_MERGED if
the IOMAP_F_MERGED flag is set.  The flags field will also come in
handy for future features such as shared extents on reflink-enabled
file systems.

Reported-by: Andreas Gruenbacher 
Signed-off-by: Christoph Hellwig 
Acked-by: Darrick J. Wong 
Signed-off-by: Dave Chinner