linux.git/fs/squashfs/block.c, branch v5.19

block: turn bio_kmalloc into a simple kmalloc wrapper

2022-04-18T01:30:41+00:00

Remove the magic autofree semantics and require the callers to explicitly
call bio_init to initialize the bio.

This allows bio_free to catch accidental bio_put calls on bio_init()ed
bios as well.

Signed-off-by: Christoph Hellwig 
Acked-by: Coly Li 
Acked-by: Mike Snitzer 
Link: https://lore.kernel.org/r/20220406061228.410163-5-hch@lst.de
Signed-off-by: Jens Axboe

squashfs: always use bio_kmalloc in squashfs_bio_read

2022-04-18T01:29:41+00:00

If a plain kmalloc that is not backed by a mempool is safe here for a
large read (and the actual page allocations), it must also be for a
small one, so simplify the code a bit.

Signed-off-by: Christoph Hellwig 
Acked-by: Phillip Lougher 
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20220406061228.410163-3-hch@lst.de
Signed-off-by: Jens Axboe

block: pass a block_device and opf to bio_alloc

2022-02-02T14:49:59+00:00

Pass the block_device and operation that we plan to use this bio for to
bio_alloc to optimize the assignment.  NULL/0 can be passed, both for the
passthrough case on a raw request_queue and to temporarily avoid
refactoring some nasty code.

Also move the gfp_mask argument after the nr_vecs argument for a much
more logical calling convention matching what most of the kernel does.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Chaitanya Kulkarni 
Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.de
Signed-off-by: Jens Axboe

squashfs: use bvec_virt

2021-08-16T16:50:32+00:00

Use bvec_virt instead of open coding it.

Signed-off-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20210804095634.460779-7-hch@lst.de
Signed-off-by: Jens Axboe

squashfs: add option to panic on errors

2021-06-29T17:53:46+00:00

Add an errors=panic mount option to make squashfs trigger a panic when
errors are encountered, similar to several other filesystems.  This allows
a kernel dump to be saved using which the corruption can be analysed and
debugged.

Inspired by a pre-fs_context patch by Anton Eliasson.

Link: https://lkml.kernel.org/r/20210527125019.14511-1-vincent.whitchurch@axis.com
Signed-off-by: Vincent Whitchurch 
Signed-off-by: Phillip Lougher 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

block: rename BIO_MAX_PAGES to BIO_MAX_VECS

2021-03-11T14:47:48+00:00

Ever since the addition of multipage bio_vecs BIO_MAX_PAGES has been
horribly confusingly misnamed.  Rename it to BIO_MAX_VECS to stop
confusing users of the bio API.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Matthew Wilcox (Oracle) 
Reviewed-by: Martin K. Petersen 
Link: https://lore.kernel.org/r/20210311110137.1132391-2-hch@lst.de
Signed-off-by: Jens Axboe

squashfs: avoid out of bounds writes in decompressors

2021-02-10T01:26:44+00:00

Patch series "Squashfs: fix BIO migration regression and add sanity checks".

Patch [1/4] fixes a regression introduced by the "migrate from
ll_rw_block usage to BIO" patch, which has produced a number of
Sysbot/Syzkaller reports.

Patches [2/4], [3/4], and [4/4] fix a number of filesystem corruption
issues which have produced Sysbot reports in the id, inode and xattr
lookup code.

Each patch has been tested against the Sysbot reproducers using the
given kernel configuration.  They have the appropriate "Reported-by:"
lines added.

Additionally, all of the reproducer filesystems are indirectly fixed by
patch [4/4] due to the fact they all have xattr corruption which is now
detected there.

Additional testing with other configurations and architectures (32bit,
big endian), and normal filesystems has also been done to trap any
inadvertent regressions caused by the additional sanity checks.

This patch (of 4):

This is a regression introduced by the patch "migrate from ll_rw_block
usage to BIO".

Sysbot/Syskaller has reported a number of "out of bounds writes" and
"unable to handle kernel paging request in squashfs_decompress" errors
which have been identified as a regression introduced by the above
patch.

Specifically, the patch removed the following sanity check

        if (length < 0 || length > output->length ||
		(index + length) > msblk->bytes_used)

This check did two things:

1. It ensured any reads were not beyond the end of the filesystem

2. It ensured that the "length" field read from the filesystem
   was within the expected maximum length.  Without this any
   corrupted values can over-run allocated buffers.

Link: https://lkml.kernel.org/r/20210204130249.4495-1-phillip@squashfs.org.uk
Link: https://lkml.kernel.org/r/20210204130249.4495-2-phillip@squashfs.org.uk
Fixes: 93e72b3c612adc ("squashfs: migrate from ll_rw_block usage to BIO")
Reported-by: syzbot+6fba78f99b9afd4b5634@syzkaller.appspotmail.com
Signed-off-by: Phillip Lougher 
Cc: Philippe Liard 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

squashfs: avoid bio_alloc() failure with 1Mbyte blocks

2020-08-21T16:52:53+00:00

This is a regression introduced by the patch "migrate from ll_rw_block
usage to BIO".

Bio_alloc() is limited to 256 pages (1 Mbyte).  This can cause a failure
when reading 1 Mbyte block filesystems.  The problem is a datablock can be
fully (or almost uncompressed), requiring 256 pages, but, because blocks
are not aligned to page boundaries, it may require 257 pages to read.

Bio_kmalloc() can handle 1024 pages, and so use this for the edge
condition.

Fixes: 93e72b3c612a ("squashfs: migrate from ll_rw_block usage to BIO")
Reported-by: Nicolas Prochazka 
Reported-by: Tomoatsu Shimada 
Signed-off-by: Phillip Lougher 
Signed-off-by: Andrew Morton 
Reviewed-by: Guenter Roeck 
Cc: Philippe Liard 
Cc: Christoph Hellwig 
Cc: Adrien Schildknecht 
Cc: Daniel Rosenberg 
Cc: 
Link: http://lkml.kernel.org/r/20200815035637.15319-1-phillip@squashfs.org.uk
Signed-off-by: Linus Torvalds

squashfs: fix length field overlap check in metadata reading

2020-07-24T19:42:41+00:00

This is a regression introduced by the "migrate from ll_rw_block usage
to BIO" patch.

Squashfs packs structures on byte boundaries, and due to that the length
field (of the metadata block) may not be fully in the current block.
The new code rewrote and introduced a faulty check for that edge case.

Fixes: 93e72b3c612adcaca1 ("squashfs: migrate from ll_rw_block usage to BIO")
Reported-by: Bernd Amend 
Signed-off-by: Phillip Lougher 
Signed-off-by: Andrew Morton 
Cc: Christoph Hellwig 
Cc: Adrien Schildknecht 
Cc: Guenter Roeck 
Cc: Daniel Rosenberg 
Link: http://lkml.kernel.org/r/20200717195536.16069-1-phillip@squashfs.org.uk
Signed-off-by: Linus Torvalds

squashfs: migrate from ll_rw_block usage to BIO

2020-06-02T17:59:05+00:00

ll_rw_block() function has been deprecated in favor of BIO which appears
to come with large performance improvements.

This patch decreases boot time by close to 40% when using squashfs for
the root file-system.  This is observed at least in the context of
starting an Android VM on Chrome OS using crosvm.  The patch was tested
on 4.19 as well as master.

This patch is largely based on Adrien Schildknecht's patch that was
originally sent as https://lkml.org/lkml/2017/9/22/814 though with some
significant changes and simplifications while also taking Phillip
Lougher's feedback into account, around preserving support for
FILE_CACHE in particular.

[akpm@linux-foundation.org: fix build error reported by Randy]
  Link: http://lkml.kernel.org/r/319997c2-5fc8-f889-2ea3-d913308a7c1f@infradead.org
Signed-off-by: Philippe Liard 
Signed-off-by: Andrew Morton 
Reviewed-by: Christoph Hellwig 
Cc: Adrien Schildknecht 
Cc: Phillip Lougher 
Cc: Guenter Roeck 
Cc: Daniel Rosenberg 
Link: https://chromium.googlesource.com/chromiumos/platform/crosvm
Link: http://lkml.kernel.org/r/20191106074238.186023-1-pliard@google.com
Signed-off-by: Linus Torvalds