linux-toradex.git/fs/btrfs/lzo.c, branch v5.1

btrfs: change set_level() to bound the level passed in

2019-02-25T13:13:32+00:00

Currently, the only user of set_level() is zlib which sets an internal
workspace parameter. As level is now plumbed into get_workspace(), this
can be handled there rather than separately.

This repurposes set_level() to bound the level passed in so it can be
used when setting the mounts compression level and as well as verifying
the level before getting a workspace. The other benefit is this divides
the meaning of compress(0) and get_workspace(0). The former means we
want to use the default compression level of the compression type. The
latter means we can use any workspace available.

Signed-off-by: Dennis Zhou 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: plumb level through the compression interface

2019-02-25T13:13:32+00:00

Zlib compression supports multiple levels, but doesn't require changing
in how a workspace itself is created and managed. Zstd introduces a
different memory requirement such that higher levels of compression
require more memory.

This requires changes in how the alloc()/get() methods work for zstd.
This pach plumbs compression level through the interface as a parameter
in preparation for zstd compression levels.  This gives the compression
types opportunity to create/manage based on the compression level.

Reviewed-by: Nikolay Borisov 
Reviewed-by: Josef Bacik 
Signed-off-by: Dennis Zhou 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: move to function pointers for get/put workspaces

2019-02-25T13:13:32+00:00

The previous patch added generic helpers for get_workspace() and
put_workspace(). Now, we can migrate ownership of the workspace_manager
to be in the compression type code as the compression code itself
doesn't care beyond being able to get a workspace. The init/cleanup and
get/put methods are abstracted so each compression algorithm can decide
how they want to manage their workspaces.

Reviewed-by: Josef Bacik 
Signed-off-by: Dennis Zhou 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: Fix typos in comments and strings

2018-12-17T13:51:50+00:00

The typos accumulate over time so once in a while time they get fixed in
a large patch.

Signed-off-by: Andrea Gelmini 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: lzo: Harden inline lzo compressed extent decompression

2018-05-30T14:46:43+00:00

For inlined extent, we only have one segment, thus less things to check.
And further more, inlined extent always has the csum in its leaf header,
it's less probable to have corrupted data.

Anyway, still check header and segment header.

Signed-off-by: Qu Wenruo 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: lzo: Add header length check to avoid potential out-of-bounds access

2018-05-30T14:46:38+00:00

James Harvey reported that some corrupted compressed extent data can
lead to various kernel memory corruption.

Such corrupted extent data belongs to inode with NODATASUM flags, thus
data csum won't help us detecting such bug.

If lucky enough, KASAN could catch it like:

BUG: KASAN: slab-out-of-bounds in lzo_decompress_bio+0x384/0x7a0 [btrfs]
Write of size 4096 at addr ffff8800606cb0f8 by task kworker/u16:0/2338

CPU: 3 PID: 2338 Comm: kworker/u16:0 Tainted: G           O      4.17.0-rc5-custom+ #50
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Workqueue: btrfs-endio btrfs_endio_helper [btrfs]
Call Trace:
 dump_stack+0xc2/0x16b
 print_address_description+0x6a/0x270
 kasan_report+0x260/0x380
 memcpy+0x34/0x50
 lzo_decompress_bio+0x384/0x7a0 [btrfs]
 end_compressed_bio_read+0x99f/0x10b0 [btrfs]
 bio_endio+0x32e/0x640
 normal_work_helper+0x15a/0xea0 [btrfs]
 process_one_work+0x7e3/0x1470
 worker_thread+0x1b0/0x1170
 kthread+0x2db/0x390
 ret_from_fork+0x22/0x40
...

The offending compressed data has the following info:

Header:			length 32768		(looks completely valid)
Segment 0 Header:	length 3472882419	(obviously out of bounds)

Then when handling segment 0, since it's over the current page, we need
the copy the compressed data to temporary buffer in workspace, then such
large size would trigger out-of-bounds memory access, screwing up the
whole kernel.

Fix it by adding extra checks on header and segment headers to ensure we
won't access out-of-bounds, and even checks the decompressed data won't
be out-of-bounds.

Reported-by: James Harvey 
Signed-off-by: Qu Wenruo 
Reviewed-by: Misono Tomohiro 
Reviewed-by: David Sterba 
[ updated comments ]
Signed-off-by: David Sterba

btrfs: lzo: document the compressed data format

2018-05-29T16:13:00+00:00

Although it's not that complex, but such comment could still save
several minutes for newer reader/reviewer instead of inferring that from
the code.

Signed-off-by: Qu Wenruo 
Reviewed-by: David Sterba 
[ minor wording updates ]
Signed-off-by: David Sterba

btrfs: replace GPL boilerplate by SPDX -- sources

2018-04-12T14:29:51+00:00

Remove GPL boilerplate text (long, short, one-line) and keep the rest,
ie. personal, company or original source copyright statements. Add the
SPDX header.

Signed-off-by: David Sterba

btrfs: Remove unused tot_len var from lzo_decompress

2018-03-30T23:26:57+00:00

Added already unused in a6fa6fae40ec ("btrfs: Add lzo compression
support").

Signed-off-by: Nikolay Borisov 
Signed-off-by: David Sterba

btrfs: allow to set compression level for zlib

2017-11-01T19:45:29+00:00

Preliminary support for setting compression level for zlib, the
following works:

$ mount -o compess=zlib                 # default
$ mount -o compess=zlib0                # same
$ mount -o compess=zlib9                # level 9, slower sync, less data
$ mount -o compess=zlib1                # level 1, faster sync, more data
$ mount -o remount,compress=zlib3	# level set by remount

The compress-force works the same as compress'.  The level is visible in
the same format in /proc/mounts. Level set via file property does not
work yet.

Required patch: "btrfs: prepare for extensions in compression options"

Signed-off-by: David Sterba