linux.git/fs/squashfs, branch v6.8

Squashfs: fix variable overflow triggered by sysbot

2023-12-11T01:21:26+00:00

Sysbot reports a slab out of bounds write in squashfs_readahead().

This is ultimately caused by a file reporting an (infeasibly) large file
size (1407374883553280 bytes) with the minimum block size of 4K.

This causes variable overflow.

Link: https://lkml.kernel.org/r/20231113160901.6444-1-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher 
Reported-by: syzbot+604424eb051c2f696163@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000b1fda20609ede0d1@google.com/
Signed-off-by: Andrew Morton

squashfs: squashfs_read_data need to check if the length is 0

2023-12-07T00:12:45+00:00

When the length passed in is 0, the pagemap_scan_test_walk() caller should
bail.  This error causes at least a WARN_ON().

Link: https://lkml.kernel.org/r/20231116031352.40853-1-lizhi.xu@windriver.com
Reported-by: syzbot+32d3767580a1ea339a81@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/0000000000000526f2060a30a085@google.com
Signed-off-by: Lizhi Xu 
Reviewed-by: Phillip Lougher 
Signed-off-by: Andrew Morton

Merge tag 'vfs-6.7.fsid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2023-11-07T20:11:26+00:00

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

Merge tag 'vfs-6.7.ctime' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs

2023-10-30T19:47:13+00:00

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
  ...

exportfs: make ->encode_fh() a mandatory method for NFS export

2023-10-28T14:15:15+00:00

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 
Reviewed-by: Jeff Layton 
Acked-by: Chuck Lever 
Signed-off-by: Amir Goldstein 
Link: https://lore.kernel.org/r/20231023180801.2953446-3-amir73il@gmail.com
Acked-by: Dave Kleikamp 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Christian Brauner

squashfs: convert to new timestamp accessors

2023-10-18T12:08:27+00:00

Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton 
Link: https://lore.kernel.org/r/20231004185347.80880-68-jlayton@kernel.org
Signed-off-by: Christian Brauner

squashfs: move squashfs_xattr_handlers to .rodata

2023-10-10T11:49:20+00:00

This makes it harder for accidental or malicious changes to
squashfs_xattr_handlers at runtime.

Cc: Phillip Lougher 
Signed-off-by: Wedson Almeida Filho 
Link: https://lore.kernel.org/r/20230930050033.41174-25-wedsonaf@gmail.com
Signed-off-by: Christian Brauner

squashfs: convert to ctime accessor functions

2023-07-24T08:30:05+00:00

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 
Reviewed-by: Jan Kara 
Message-Id: <20230705190309.579783-73-jlayton@kernel.org>
Signed-off-by: Christian Brauner

squashfs: fix cache race with migration

2023-07-08T16:29:30+00:00

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: e994f5b677ee ("squashfs: cache partial compressed blocks")
Signed-off-by: Vincent Whitchurch 
Cc: Christoph Hellwig 
Cc: Phillip Lougher 
Signed-off-by: Andrew Morton

squashfs: cache partial compressed blocks

2023-06-10T00:44:14+00:00

Before commit 93e72b3c612adcaca1 ("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 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Phillip Lougher 
Signed-off-by: Andrew Morton