Commit Graph

241 Commits

Author SHA1 Message Date
Linus Torvalds
13d88ac54d Merge tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fanotify fsid updates from Christian Brauner:
 "This work is part of the plan to enable fanotify to serve as a drop-in
  replacement for inotify. While inotify is availabe on all filesystems,
  fanotify currently isn't.

  In order to support fanotify on all filesystems two things are needed:

   (1) all filesystems need to support AT_HANDLE_FID

   (2) all filesystems need to report a non-zero f_fsid

  This contains (1) and allows filesystems to encode non-decodable file
  handlers for fanotify without implementing any exportfs operations by
  encoding a file id of type FILEID_INO64_GEN from i_ino and
  i_generation.

  Filesystems that want to opt out of encoding non-decodable file ids
  for fanotify that don't support NFS export can do so by providing an
  empty export_operations struct.

  This also partially addresses (2) by generating f_fsid for simple
  filesystems as well as freevxfs. Remaining filesystems will be dealt
  with by separate patches.

  Finally, this contains the patch from the current exportfs maintainers
  which moves exportfs under vfs with Chuck, Jeff, and Amir as
  maintainers and vfs.git as tree"

* tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  MAINTAINERS: create an entry for exportfs
  fs: fix build error with CONFIG_EXPORTFS=m or not defined
  freevxfs: derive f_fsid from bdev->bd_dev
  fs: report f_fsid from s_dev for "simple" filesystems
  exportfs: support encoding non-decodeable file handles by default
  exportfs: define FILEID_INO64_GEN* file handle types
  exportfs: make ->encode_fh() a mandatory method for NFS export
  exportfs: add helpers to check if filesystem can encode/decode file handles
2023-11-07 12:11:26 -08:00
Linus Torvalds
14ab6d425e Merge tag 'vfs-6.7.ctime' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs
Pull vfs inode time accessor updates from Christian Brauner:
 "This finishes the conversion of all inode time fields to accessor
  functions as discussed on list. Changing timestamps manually as we
  used to do before is error prone. Using accessors function makes this
  robust.

  It does not contain the switch of the time fields to discrete 64 bit
  integers to replace struct timespec and free up space in struct inode.
  But after this, the switch can be trivially made and the patch should
  only affect the vfs if we decide to do it"

* tag 'vfs-6.7.ctime' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (86 commits)
  fs: rename inode i_atime and i_mtime fields
  security: convert to new timestamp accessors
  selinux: convert to new timestamp accessors
  apparmor: convert to new timestamp accessors
  sunrpc: convert to new timestamp accessors
  mm: convert to new timestamp accessors
  bpf: convert to new timestamp accessors
  ipc: convert to new timestamp accessors
  linux: convert to new timestamp accessors
  zonefs: convert to new timestamp accessors
  xfs: convert to new timestamp accessors
  vboxsf: convert to new timestamp accessors
  ufs: convert to new timestamp accessors
  udf: convert to new timestamp accessors
  ubifs: convert to new timestamp accessors
  tracefs: convert to new timestamp accessors
  sysv: convert to new timestamp accessors
  squashfs: convert to new timestamp accessors
  server: convert to new timestamp accessors
  client: convert to new timestamp accessors
  ...
2023-10-30 09:47:13 -10:00
Amir Goldstein
e21fc2038c exportfs: make ->encode_fh() a mandatory method for NFS export
Rename the default helper for encoding FILEID_INO32_GEN* file handles to
generic_encode_ino32_fh() and convert the filesystems that used the
default implementation to use the generic helper explicitly.

After this change, exportfs_encode_inode_fh() no longer has a default
implementation to encode FILEID_INO32_GEN* file handles.

This is a step towards allowing filesystems to encode non-decodeable
file handles for fanotify without having to implement any
export_operations.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231023180801.2953446-3-amir73il@gmail.com
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-28 16:15:15 +02:00
Jeff Layton
a1f13ed8c7 squashfs: convert to new timestamp accessors
Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20231004185347.80880-68-jlayton@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-18 14:08:27 +02:00
Wedson Almeida Filho
c08a831c74 squashfs: move squashfs_xattr_handlers to .rodata
This makes it harder for accidental or malicious changes to
squashfs_xattr_handlers at runtime.

Cc: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20230930050033.41174-25-wedsonaf@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-10-10 13:49:20 +02:00
Jeff Layton
280345d0d0 squashfs: convert to ctime accessor functions
In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-73-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2023-07-24 10:30:05 +02:00
Vincent Whitchurch
08bab74ae6 squashfs: fix cache race with migration
Migration replaces the page in the mapping before copying the contents and
the flags over from the old page, so check that the page in the page cache
is really up to date before using it.  Without this, stressing squashfs
reads with parallel compaction sometimes results in squashfs reporting
data corruption.

Link: https://lkml.kernel.org/r/20230629-squashfs-cache-migration-v1-1-d50ebe55099d@axis.com
Fixes: e994f5b677 ("squashfs: cache partial compressed blocks")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-08 09:29:30 -07:00
Vincent Whitchurch
e994f5b677 squashfs: cache partial compressed blocks
Before commit 93e72b3c61 ("squashfs: migrate from ll_rw_block
usage to BIO"), compressed blocks read by squashfs were cached in the page
cache, but that is not the case after that commit.  That has lead to
squashfs having to re-read a lot of sectors from disk/flash.

For example, the first sectors of every metadata block need to be read
twice from the disk.  Once partially to read the length, and a second time
to read the block itself.  Also, in linear reads of large files, the last
sectors of one data block are re-read from disk when reading the next data
block, since the compressed blocks are of variable sizes and not aligned
to device blocks.  This extra I/O results in a degrade in read performance
of, for example, ~16% in one scenario on my ARM platform using squashfs
with dm-verity and NAND.

Since the decompressed data is cached in the page cache or squashfs'
internal metadata and fragment caches, caching _all_ compressed pages
would lead to a lot of double caching and is undesirable.  But make the
code cache any disk blocks which were only partially requested, since
these are the ones likely to include data which is needed by other file
system blocks.  This restores read performance in my test scenario.

The compressed block caching is only applied when the disk block size is
equal to the page size, to avoid having to deal with caching sub-page
reads.

[akpm@linux-foundation.org: fs/squashfs/block.c needs linux/pagemap.h]
[vincent.whitchurch@axis.com: fix page update race]
  Link: https://lkml.kernel.org/r/20230526-squashfs-cache-fixup-v1-1-d54a7fa23e7b@axis.com
[vincent.whitchurch@axis.com: fix page indices]
  Link: https://lkml.kernel.org/r/20230526-squashfs-cache-fixup-v1-2-d54a7fa23e7b@axis.com
[akpm@linux-foundation.org: fix layout, per hch]
Link: https://lkml.kernel.org/r/20230510-squashfs-cache-v4-1-3bd394e1ee71@axis.com
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 17:44:14 -07:00
Christoph Hellwig
6b81459c9c squashfs: don't include buffer_head.h
Squashfs has stopped using buffers heads in 93e72b3c61
("squashfs: migrate from ll_rw_block usage to BIO").

Link: https://lkml.kernel.org/r/20230517071622.245151-1-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-09 17:44:14 -07:00
Andrew Morton
a5b21d8d79 revert "squashfs: harden sanity check in squashfs_read_xattr_id_table"
This fix was nacked by Philip, for reasons identified in the email linked
below.

Link: https://lkml.kernel.org/r/68f15d67-8945-2728-1f17-5b53a80ec52d@squashfs.org.uk
Fixes: 72e544b1b2 ("squashfs: harden sanity check in squashfs_read_xattr_id_table")
Cc: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Fedor Pchelkin <pchelkin@ispras.ru>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-03 17:52:25 -08:00
Phillip Lougher
f65c4bbbd6 Squashfs: fix handling and sanity checking of xattr_ids count
A Sysbot [1] corrupted filesystem exposes two flaws in the handling and
sanity checking of the xattr_ids count in the filesystem.  Both of these
flaws cause computation overflow due to incorrect typing.

In the corrupted filesystem the xattr_ids value is 4294967071, which
stored in a signed variable becomes the negative number -225.

Flaw 1 (64-bit systems only):

The signed integer xattr_ids variable causes sign extension.

This causes variable overflow in the SQUASHFS_XATTR_*(A) macros.  The
variable is first multiplied by sizeof(struct squashfs_xattr_id) where the
type of the sizeof operator is "unsigned long".

On a 64-bit system this is 64-bits in size, and causes the negative number
to be sign extended and widened to 64-bits and then become unsigned.  This
produces the very large number 18446744073709548016 or 2^64 - 3600.  This
number when rounded up by SQUASHFS_METADATA_SIZE - 1 (8191 bytes) and
divided by SQUASHFS_METADATA_SIZE overflows and produces a length of 0
(stored in len).

Flaw 2 (32-bit systems only):

On a 32-bit system the integer variable is not widened by the unsigned
long type of the sizeof operator (32-bits), and the signedness of the
variable has no effect due it always being treated as unsigned.

The above corrupted xattr_ids value of 4294967071, when multiplied
overflows and produces the number 4294963696 or 2^32 - 3400.  This number
when rounded up by SQUASHFS_METADATA_SIZE - 1 (8191 bytes) and divided by
SQUASHFS_METADATA_SIZE overflows again and produces a length of 0.

The effect of the 0 length computation:

In conjunction with the corrupted xattr_ids field, the filesystem also has
a corrupted xattr_table_start value, where it matches the end of
filesystem value of 850.

This causes the following sanity check code to fail because the
incorrectly computed len of 0 matches the incorrect size of the table
reported by the superblock (0 bytes).

    len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids);
    indexes = SQUASHFS_XATTR_BLOCKS(*xattr_ids);

    /*
     * The computed size of the index table (len bytes) should exactly
     * match the table start and end points
    */
    start = table_start + sizeof(*id_table);
    end = msblk->bytes_used;

    if (len != (end - start))
            return ERR_PTR(-EINVAL);

Changing the xattr_ids variable to be "usigned int" fixes the flaw on a
64-bit system.  This relies on the fact the computation is widened by the
unsigned long type of the sizeof operator.

Casting the variable to u64 in the above macro fixes this flaw on a 32-bit
system.

It also means 64-bit systems do not implicitly rely on the type of the
sizeof operator to widen the computation.

[1] https://lore.kernel.org/lkml/000000000000cd44f005f1a0f17f@google.com/

Link: https://lkml.kernel.org/r/20230127061842.10965-1-phillip@squashfs.org.uk
Fixes: 506220d2ba ("squashfs: add more sanity checks in xattr id lookup")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: <syzbot+082fa4af80a5bb1a9843@syzkaller.appspotmail.com>
Cc: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Fedor Pchelkin <pchelkin@ispras.ru>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-31 16:44:10 -08:00
Fedor Pchelkin
72e544b1b2 squashfs: harden sanity check in squashfs_read_xattr_id_table
While mounting a corrupted filesystem, a signed integer '*xattr_ids' can
become less than zero.  This leads to the incorrect computation of 'len'
and 'indexes' values which can cause null-ptr-deref in copy_bio_to_actor()
or out-of-bounds accesses in the next sanity checks inside
squashfs_read_xattr_id_table().

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Link: https://lkml.kernel.org/r/20230117105226.329303-2-pchelkin@ispras.ru
Fixes: 506220d2ba ("squashfs: add more sanity checks in xattr id lookup")
Reported-by: <syzbot+082fa4af80a5bb1a9843@syzkaller.appspotmail.com>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-31 16:44:08 -08:00
Linus Torvalds
6e8948a063 Merge tag 'fs.idmapped.squashfs.v6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping
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
2022-12-12 20:24:51 -08:00
Baokun Li
c7e8d3279c squashfs: fix null-ptr-deref in squashfs_fill_super
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:
 <TASK>
 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
 </TASK>
==================================================================

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=<single|multi|percpu>")
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Xiaoming Ni <nixiaoming@huawei.com>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-18 13:55:09 -08:00
Xiaoming Ni
fb40fe04f9 squashfs: allows users to configure the number of decompression threads
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 <nixiaoming@huawei.com>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Jianguo Chen <chenjianguo3@huawei.com>
Cc: Jubin Zhong <zhongjubin@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-18 13:55:08 -08:00
Xiaoming Ni
80f784098f squashfs: add the mount parameter theads=<single|multi|percpu>
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=<single|multi|percpu|1|2|3|...>"
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=<single|multi|percpu> 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 <nixiaoming@huawei.com>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Jianguo Chen <chenjianguo3@huawei.com>
Cc: Jubin Zhong <zhongjubin@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-18 13:55:08 -08:00
Michael Weiß
42da66ac7b squashfs: enable idmapped mounts
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 <michael.weiss@aisec.fraunhofer.de>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-11-07 10:24:22 +01:00
Phillip Lougher
e11c4e088b squashfs: fix buffer release race condition in readahead code
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: b09a7a036d ("squashfs: support reading fragments in readahead call")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reported-by: Marc Miltenberger <marcmiltenberger@gmail.com>
Cc: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Cc: Slade Watkins <srw@sladewatkins.net>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:21 -07:00
Phillip Lougher
c9199de82b squashfs: fix extending readahead beyond end of file
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: 8fc78b6fe2 ("squashfs: implement readahead")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reported-by: Marc Miltenberger <marcmiltenberger@gmail.com>
Cc: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Cc: Slade Watkins <srw@sladewatkins.net>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:21 -07:00
Phillip Lougher
9ef8eb6104 squashfs: fix read regression introduced in readahead code
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: 8fc78b6fe2 ("squashfs: implement readahead")
Link: https://lore.kernel.org/lkml/b0c258c3-6dcf-aade-efc4-d62a8b3a1ce2@alu.unizg.hr/
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Tested-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Tested-by: Slade Watkins <srw@sladewatkins.net>
Tested-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reported-by: Marc Miltenberger <marcmiltenberger@gmail.com>
Cc: Dimitri John Ledkov <dimitri.ledkov@canonical.com>
Cc: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-28 13:37:21 -07:00
Phillip Lougher
1f13dff09f squashfs: don't call kmalloc in decompressors
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
f268eedddf ("squashfs: extend "page actor" to handle missing pages")

Link: https://lkml.kernel.org/r/20220822215430.15933-1-phillip@squashfs.org.uk
Fixes: f268eedddf ("squashfs: extend "page actor" to handle missing pages")
Reported-by: Chris Murphy <lists@colorremedies.com>
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-28 14:02:45 -07:00
Linus Torvalds
eb5699ba31 Merge tag 'mm-nonmm-stable-2022-08-06-2' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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
  ...
2022-08-07 10:03:24 -07:00
Matthew Wilcox (Oracle)
31e748e4b1 squashfs: Return the actual error from squashfs_read_folio()
Since we actually know what error happened, we can report it instead
of having the generic code return -EIO for pages that were unlocked
without being marked uptodate.  Also remove a test of PageError since
we have the return value at this point.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
2022-08-02 12:34:02 -04:00
Phillip Lougher
b09a7a036d squashfs: support reading fragments in readahead call
Add a function which can be used to read fragments in the readahead call.

This function is necessary because filesystems built with the -tailends
(or -always-use-fragments) option may have fragments present which cannot
be currently handled.

Link: https://lkml.kernel.org/r/20220617083810.337573-5-hsinyi@chromium.org
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Cc: Hou Tao <houtao1@huawei.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: Xiongwei Song <Xiongwei.Song@windriver.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Cc: Zheng Liang <zhengliang6@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-29 18:12:34 -07:00
Hsin-Yi Wang
8fc78b6fe2 squashfs: implement readahead
Implement readahead callback for squashfs.  It will read datablocks which
cover pages in readahead request.  For a few cases it will not mark page
as uptodate, including:

- file end is 0.
- zero filled blocks.
- current batch of pages isn't in the same datablock.
- decompressor error.

Otherwise pages will be marked as uptodate.  The unhandled pages will be
updated by readpage later.

Link: https://lkml.kernel.org/r/20220617083810.337573-4-hsinyi@chromium.org
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Suggested-by: Matthew Wilcox <willy@infradead.org>
Reported-by: Matthew Wilcox <willy@infradead.org>
Reported-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: Xiongwei Song <Xiongwei.Song@windriver.com>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hou Tao <houtao1@huawei.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Miao Xie <miaoxie@huawei.com>
Cc: Zhang Yi <yi.zhang@huawei.com>
Cc: Zheng Liang <zhengliang6@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-29 18:12:34 -07:00