linux-toradex.git/fs/xfs/xfs_buf.c, branch v4.18

xfs: xfs_reflink_convert_cow() memory allocation deadlock

2018-06-08T17:07:51+00:00

xfs_reflink_convert_cow() manipulates the incore extent list
in GFP_KERNEL context in the IO submission path whilst holding
locked pages under writeback. This is a memory reclaim deadlock
vector. This code is not in a transaction, so any memory allocations
it makes aren't protected via the memalloc_nofs_save() context that
transactions carry.

Hence we need to run this call under memalloc_nofs_save() context to
prevent potential memory allocations from being run as GFP_KERNEL
and deadlocking.

Signed-Off-By: Dave Chinner 
Reviewed-by: Allison Henderson 
Reviewed-by: Brian Foster 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

xfs: convert to SPDX license tags

2018-06-06T21:17:53+00:00

Remove the verbose license text from XFS files and replace them
with SPDX tags. This does not change the license of any of the code,
merely refers to the common, up-to-date license files in LICENSES/

This change was mostly scripted. fs/xfs/Makefile and
fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected
and modified by the following command:

for f in `git grep -l "GNU General" fs/xfs/` ; do
	echo $f
	cat $f | awk -f hdr.awk > $f.new
	mv -f $f.new $f
done

And the hdr.awk script that did the modification (including
detecting the difference between GPL-2.0 and GPL-2.0+ licenses)
is as follows:

$ cat hdr.awk
BEGIN {
	hdr = 1.0
	tag = "GPL-2.0"
	str = ""
}

/^ \* This program is free software/ {
	hdr = 2.0;
	next
}

/any later version./ {
	tag = "GPL-2.0+"
	next
}

/^ \*\// {
	if (hdr > 0.0) {
		print "// SPDX-License-Identifier: " tag
		print str
		print $0
		str=""
		hdr = 0.0
		next
	}
	print $0
	next
}

/^ \* / {
	if (hdr > 1.0)
		next
	if (hdr > 0.0) {
		if (str != "")
			str = str "\n"
		str = str $0
		next
	}
	print $0
	next
}

/^ \*/ {
	if (hdr > 0.0)
		next
	print $0
	next
}

// {
	if (hdr > 0.0) {
		if (str != "")
			str = str "\n"
		str = str $0
		next
	}
	print $0
}

END { }
$

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

xfs: don't retry xfs_buf_find on XBF_TRYLOCK failure

2018-05-09T17:04:00+00:00

When looking at an event trace recently, I noticed that non-blocking
buffer lookup attempts would fail on cached locked buffers and then
run the slow cache-miss path. This means we are doing an xfs_buf
allocation, lookup and free unnecessarily every time we avoid
blocking on a locked buffer.

Fix this by changing _xfs_buf_find() to return an error status to
the caller to indicate that we failed the lock attempt rather than
just returning a NULL. This allows the higher level code to
discriminate between a cache miss and an cache hit that we failed to
lock.

This also allows us to return a -EFSCORRUPTED state if we are asked
to look up a block number outside the range of the filesystem in
_xfs_buf_find(), which moves us one step closer to being able to
handle such errors in a more graceful manner at the higher levels.

Signed-Off-By: Dave Chinner 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Carlos Maiolino 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

xfs: make xfs_buf_incore out of line

2018-05-09T17:04:00+00:00

Move xfs_buf_incore out of line and make it the only way to look up
a buffer in the buffer cache from outside the buffer cache. Convert
the external users of _xfs_buf_find() to xfs_buf_incore() and make
_xfs_buf_find() static.

Signed-Off-By: Dave Chinner 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Carlos Maiolino 
Reviewed-by: Darrick J. Wong 
[darrick: actually rename xfs_incore -> xfs_buf_incore]
Signed-off-by: Darrick J. Wong

xfs: non-scrub - remove unused function parameters

2018-04-09T17:23:42+00:00

Signed-off-by: Eric Sandeen 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

xfs: Correctly invert xfs_buftarg LRU isolation logic

2018-03-12T03:27:56+00:00

Due to an inverted logic mistake in xfs_buftarg_isolate()
the xfs_buffers with zero b_lru_ref will take another trip
around LRU, while isolating buffers with non-zero b_lru_ref.

Additionally those isolated buffers end up right back on the LRU
once they are released, because b_lru_ref remains elevated.

Fix that circuitous route by leaving them on the LRU
as originally intended.

Signed-off-by: Vratislav Bendel 
Reviewed-by: Brian Foster 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

Use list_head infra-structure for buffer's log items list

2018-01-29T15:27:22+00:00

Now that buffer's b_fspriv has been split, just replace the current
singly linked list of xfs_log_items, by the list_head infrastructure.

Also, remove the xfs_log_item argument from xfs_buf_resubmit_failed_buffers(),
there is no need for this argument, once the log items can be walked
through the list_head in the buffer.

Signed-off-by: Carlos Maiolino 
Reviewed-by: Bill O'Donnell 
Reviewed-by: Darrick J. Wong 
[darrick: minor style cleanups]
Signed-off-by: Darrick J. Wong

xfs: clarify units in the failed metadata io message

2018-01-09T23:18:07+00:00

If a metadata IO error happens, we report the location of the failed IO
request in units of daddrs.  However, the printk message misleads people
into thinking that the units are fs blocks, so fix the reported units.

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

xfs: dump the first 128 bytes of any corrupt buffer

2018-01-08T18:54:47+00:00

Increase the corrupt buffer dump to the first 128 bytes since v5
filesystems have larger block headers than before.

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

xfs: refactor xfs_verifier_error and xfs_buf_ioerror

2018-01-08T18:54:45+00:00

Since all verification errors also mark the buffer as having an error,
we can combine these two calls.  Later we'll add a xfs_failaddr_t
parameter to promote the idea of reporting corruption errors and the
address of the failing check to enable better debugging reports.

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