linux.git/fs/squashfs, branch v6.2-rc2

Merge tag 'fs.idmapped.squashfs.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

2022-12-13T04:24:51+00:00

Pull squashfs update from Seth Forshee:
 "This is a simple patch to enable idmapped mounts for squashfs.

  All functionality squashfs needs to support idmapped mounts is already
  implemented in generic VFS code, so all that is needed is to set
  FS_ALLOW_IDMAP in fs_flags"

* tag 'fs.idmapped.squashfs.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping:
  squashfs: enable idmapped mounts

squashfs: fix null-ptr-deref in squashfs_fill_super

2022-11-18T21:55:09+00:00

When squashfs_read_table() returns an error or `sb->s_magic !=
SQUASHFS_MAGIC`, enters the error branch and calls
msblk->thread_ops->destroy(msblk) to destroy msblk.  However,
msblk->thread_ops has not been initialized.  Therefore, the following
problem is triggered:

==================================================================
BUG: KASAN: null-ptr-deref in squashfs_fill_super+0xe7a/0x13b0
Read of size 8 at addr 0000000000000008 by task swapper/0/1

CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.1.0-rc3-next-20221031 #367
Call Trace:
 
 dump_stack_lvl+0x73/0x9f
 print_report+0x743/0x759
 kasan_report+0xc0/0x120
 __asan_load8+0xd3/0x140
 squashfs_fill_super+0xe7a/0x13b0
 get_tree_bdev+0x27b/0x450
 squashfs_get_tree+0x19/0x30
 vfs_get_tree+0x49/0x150
 path_mount+0xaae/0x1350
 init_mount+0xad/0x100
 do_mount_root+0xbc/0x1d0
 mount_block_root+0x173/0x316
 mount_root+0x223/0x236
 prepare_namespace+0x1eb/0x237
 kernel_init_freeable+0x528/0x576
 kernel_init+0x29/0x250
 ret_from_fork+0x1f/0x30
 
==================================================================

To solve this issue, msblk->thread_ops is initialized immediately after
msblk is assigned a value.

Link: https://lkml.kernel.org/r/20221101073343.3961562-1-libaokun1@huawei.com
Fixes: b0645770d3c7 ("squashfs: add the mount parameter theads=")
Signed-off-by: Baokun Li 
Reviewed-by: Xiaoming Ni 
Reviewed-by: Phillip Lougher 
Cc: Yu Kuai 
Cc: Zhang Yi 
Signed-off-by: Andrew Morton

squashfs: allows users to configure the number of decompression threads

2022-11-18T21:55:08+00:00

The maximum number of threads in the decompressor_multi.c file is fixed
and cannot be adjusted according to user needs.  Therefore, the mount
parameter needs to be added to allow users to configure the number of
threads as required.  The upper limit is num_online_cpus() * 2.

Link: https://lkml.kernel.org/r/20221019030930.130456-3-nixiaoming@huawei.com
Signed-off-by: Xiaoming Ni 
Reviewed-by: Phillip Lougher 
Cc: Jianguo Chen 
Cc: Jubin Zhong 
Cc: Zhang Yi 
Signed-off-by: Andrew Morton

squashfs: add the mount parameter theads=

2022-11-18T21:55:08+00:00

Patch series 'squashfs: Add the mount parameter "threads="'.

Currently, Squashfs supports multiple decompressor parallel modes. 
However, this mode can be configured only during kernel building and does
not support flexible selection during runtime.

In the current patch set, the mount parameter "threads=" is added to allow
users to select the parallel decompressor mode and configure the number of
decompressors when mounting a file system.

"threads="
The upper limit is num_online_cpus() * 2.


This patch (of 2):

Squashfs supports three decompression concurrency modes:
	Single-thread mode: concurrent reads are blocked and the memory
		overhead is small.
	Multi-thread mode/percpu mode: reduces concurrent read blocking but
		increases memory overhead.

The corresponding schema must be fixed at compile time. During mounting,
the concurrent decompression mode cannot be adjusted based on file read
blocking.

The mount parameter theads= is added to select
the concurrent decompression mode of a single SquashFS file system
image.

Link: https://lkml.kernel.org/r/20221019030930.130456-1-nixiaoming@huawei.com
Link: https://lkml.kernel.org/r/20221019030930.130456-2-nixiaoming@huawei.com
Signed-off-by: Xiaoming Ni 
Reviewed-by: Phillip Lougher 
Cc: Jianguo Chen 
Cc: Jubin Zhong 
Cc: Zhang Yi 
Signed-off-by: Andrew Morton

squashfs: enable idmapped mounts

2022-11-07T09:24:22+00:00

For squashfs all needed functionality for idmapped mounts is already
implemented by the generic handlers in the VFS. Thus, it is sufficient
to just enable the corresponding FS_ALLOW_IDMAP flag to support
idmapped mounts.

We use this for unprivileged (user namespaced) containers based on
squashfs images as rootfs in GyroidOS.

A simple test using the mount-idmapped tool executed as user with
uid=1000 looks as follows:

$ mkdir test
$ echo "test" > test/test_file
$ mksquashfs test/ fs.img
$ sudo mkdir /mnt/test
$ sudo mkdir /mnt/mapped
$ sudo mount fs.img -o loop /mnt/test/
$ sudo ./mount-idmapped --map-mount b:1000:2000:1 /mnt/test/ /mnt/mapped/

$ mount | tail -n2
fs.img on /mnt/test type squashfs (ro,relatime,errors=continue)
fs.img on /mnt/mapped type squashfs (ro,relatime,idmapped,errors=continue)

$ ls -lan /mnt/test/
total 5
drwxr-xr-x 2 1000 1000   32 Okt 24 13:36 .
drwxr-xr-x 6    0    0 4096 Okt 24 13:38 ..
-rw-r--r-- 1 1000 1000    5 Okt 24 13:36 test_file

$ ls -lan /mnt/mapped/
total 5
drwxr-xr-x 2 2000 2000   32 Okt 24 13:36 .
drwxr-xr-x 6    0    0 4096 Okt 24 13:38 ..
-rw-r--r-- 1 2000 2000    5 Okt 24 13:36 test_file

Signed-off-by: Michael Weiß 
Reviewed-by: Christian Brauner 
Reviewed-by: Phillip Lougher 
Signed-off-by: Christian Brauner (Microsoft)

squashfs: fix buffer release race condition in readahead code

2022-10-28T20:37:21+00:00

Fix a buffer release race condition, where the error value was used after
release.

Link: https://lkml.kernel.org/r/20221020223616.7571-4-phillip@squashfs.org.uk
Fixes: b09a7a036d20 ("squashfs: support reading fragments in readahead call")
Signed-off-by: Phillip Lougher 
Tested-by: Bagas Sanjaya 
Reported-by: Marc Miltenberger 
Cc: Dimitri John Ledkov 
Cc: Hsin-Yi Wang 
Cc: Mirsad Goran Todorovac 
Cc: Slade Watkins 
Cc: Thorsten Leemhuis 
Cc: 
Signed-off-by: Andrew Morton

squashfs: fix extending readahead beyond end of file

2022-10-28T20:37:21+00:00

The readahead code will try to extend readahead to the entire size of the
Squashfs data block.

But, it didn't take into account that the last block at the end of the
file may not be a whole block.  In this case, the code would extend
readahead to beyond the end of the file, leaving trailing pages.

Fix this by only requesting the expected number of pages.

Link: https://lkml.kernel.org/r/20221020223616.7571-3-phillip@squashfs.org.uk
Fixes: 8fc78b6fe24c ("squashfs: implement readahead")
Signed-off-by: Phillip Lougher 
Tested-by: Bagas Sanjaya 
Reported-by: Marc Miltenberger 
Cc: Dimitri John Ledkov 
Cc: Hsin-Yi Wang 
Cc: Mirsad Goran Todorovac 
Cc: Slade Watkins 
Cc: Thorsten Leemhuis 
Cc: 

Signed-off-by: Andrew Morton

squashfs: fix read regression introduced in readahead code

2022-10-28T20:37:21+00:00

Patch series "squashfs: fix some regressions introduced in the readahead
code".

This patchset fixes 3 regressions introduced by the recent readahead code
changes.  The first regression is causing "snaps" to randomly fail after a
couple of hours or days, which how the regression came to light.


This patch (of 3):

If a file isn't a whole multiple of the page size, the last page will have
trailing bytes unfilled.

There was a mistake in the readahead code which did this.  In particular
it incorrectly assumed that the last page in the readahead page array
(page[nr_pages - 1]) will always contain the last page in the block, which
if we're at file end, will be the page that needs to be zero filled.

But the readahead code may not return the last page in the block, which
means it is unmapped and will be skipped by the decompressors (a temporary
buffer used).

In this case the zero filling code will zero out the wrong page, leading
to data corruption.

Fix this by by extending the "page actor" to return the last page if
present, or NULL if a temporary buffer was used.

Link: https://lkml.kernel.org/r/20221020223616.7571-1-phillip@squashfs.org.uk
Link: https://lkml.kernel.org/r/20221020223616.7571-2-phillip@squashfs.org.uk
Fixes: 8fc78b6fe24c ("squashfs: implement readahead")
Link: https://lore.kernel.org/lkml/b0c258c3-6dcf-aade-efc4-d62a8b3a1ce2@alu.unizg.hr/
Signed-off-by: Phillip Lougher 
Reported-by: Mirsad Goran Todorovac 
Tested-by: Mirsad Goran Todorovac 
Tested-by: Slade Watkins 
Tested-by: Bagas Sanjaya 
Reported-by: Marc Miltenberger 
Cc: Dimitri John Ledkov 
Cc: Hsin-Yi Wang 
Cc: Thorsten Leemhuis 
Cc: 
Signed-off-by: Andrew Morton

squashfs: don't call kmalloc in decompressors

2022-08-28T21:02:45+00:00

The decompressors may be called while in an atomic section.  So move the
kmalloc() out of this path, and into the "page actor" init function.

This fixes a regression introduced by commit
f268eedddf35 ("squashfs: extend "page actor" to handle missing pages")

Link: https://lkml.kernel.org/r/20220822215430.15933-1-phillip@squashfs.org.uk
Fixes: f268eedddf35 ("squashfs: extend "page actor" to handle missing pages")
Reported-by: Chris Murphy 
Signed-off-by: Phillip Lougher 
Cc: 
Signed-off-by: Andrew Morton

Merge tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-08-07T17:03:24+00:00

Pull misc updates from Andrew Morton:
 "Updates to various subsystems which I help look after. lib, ocfs2,
  fatfs, autofs, squashfs, procfs, etc. A relatively small amount of
  material this time"

* tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
  scripts/gdb: ensure the absolute path is generated on initial source
  MAINTAINERS: kunit: add David Gow as a maintainer of KUnit
  mailmap: add linux.dev alias for Brendan Higgins
  mailmap: update Kirill's email
  profile: setup_profiling_timer() is moslty not implemented
  ocfs2: fix a typo in a comment
  ocfs2: use the bitmap API to simplify code
  ocfs2: remove some useless functions
  lib/mpi: fix typo 'the the' in comment
  proc: add some (hopefully) insightful comments
  bdi: remove enum wb_congested_state
  kernel/hung_task: fix address space of proc_dohung_task_timeout_secs
  lib/lzo/lzo1x_compress.c: replace ternary operator with min() and min_t()
  squashfs: support reading fragments in readahead call
  squashfs: implement readahead
  squashfs: always build "file direct" version of page actor
  Revert "squashfs: provide backing_dev_info in order to disable read-ahead"
  fs/ocfs2: Fix spelling typo in comment
  ia64: old_rr4 added under CONFIG_HUGETLB_PAGE
  proc: fix test for "vsyscall=xonly" boot option
  ...