In the recent work to remove page->index, a sanity check
that ensured all the readhead pages were covered by the
Squashfs data block was removed [1].
To avoid any regression, this commit adds the sanity check
back in an equivalent way. Namely the page actor will now
return error if any pages are unused after completion.
[1] https://lore.kernel.org/all/20240818235847.170468-3-phillip@squashfs.org.uk/
--
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Link: https://lore.kernel.org/r/20240822233106.121522-1-phillip@squashfs.org.uk
V3: last_page should be actor->last_page
Signed-off-by: Christian Brauner <brauner@kernel.org>
The previous implementation lacked error checking (e.g. the bytes
returned by squashfs_fill_page() is not checked), and the use of
page->index could not be removed without substantially rewriting
the routine to use the page actor abstraction used elsewhere.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Link: https://lore.kernel.org/r/20240818235847.170468-5-phillip@squashfs.org.uk
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit removes references to page->index in the pages returned
from __readahead_batch(), and instead uses the 'start' variable.
This does reveal a bug in the previous code in that 'start' was
not updated every time around the loop. This is fixed in this
commit.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Link: https://lore.kernel.org/r/20240818235847.170468-3-phillip@squashfs.org.uk
Signed-off-by: Christian Brauner <brauner@kernel.org>
Nobody checks the error flag on squashfs folios, so stop setting it.
Link: https://lkml.kernel.org/r/20240420025029.2166544-24-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Phillip Lougher <phillip@squashfs.org.uk>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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>
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>
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>
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>
fatfs, autofs, squashfs, procfs, etc.
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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
...
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>
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>
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>
This is a "weak" conversion which converts straight back to using pages.
A full conversion should be performed at some point, hopefully by
someone familiar with the filesystem.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Sysbot has reported a "divide error" which has been identified as being
caused by a corrupted file_size value within the file inode. This value
has been corrupted to a much larger value than expected.
Calculate_skip() is passed i_size_read(inode) >> msblk->block_log. Due to
the file_size value corruption this overflows the int argument/variable in
that function, leading to the divide error.
This patch changes the function to use u64. This will accommodate any
unexpectedly large values due to corruption.
The value returned from calculate_skip() is clamped to be never more than
SQUASHFS_CACHED_BLKS - 1, or 7. So file_size corruption does not lead to
an unexpectedly large return result here.
Link: https://lkml.kernel.org/r/20210507152618.9447-1-phillip@squashfs.org.uk
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reported-by: <syzbot+e8f781243ce16ac2f962@syzkaller.appspotmail.com>
Reported-by: <syzbot+7b98870d4fec9447b951@syzkaller.appspotmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 or at your option any
later version this program is distributed in the hope that it will
be useful but without any warranty without even the implied warranty
of merchantability or fitness for a particular purpose see the gnu
general public license for more details you should have received a
copy of the gnu general public license along with this program if
not write to the free software foundation 51 franklin street fifth
floor boston ma 02110 1301 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 23 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190520170857.458548087@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Previously in squashfs_readpage() when copying data into the page
cache, it used the length of the datablock read from the filesystem
(after decompression). However, if the filesystem has been corrupted
this data block may be short, which will leave pages unfilled.
The fix for this is to compute the expected number of bytes to copy
from the inode size, and use this to detect if the block is short.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Tested-by: Willy Tarreau <w@1wt.eu>
Cc: Анатолий Тросиненко <anatoly.trosinenko@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Anatoly continues to find issues with fuzzed squashfs images.
This time, corrupt, missing, or undersized data for the page filling
wasn't checked for, because the squashfs_{copy,read}_cache() functions
did the squashfs_copy_data() call without checking the resulting data
size.
Which could result in the page cache pages being incompletely filled in,
and no error indication to the user space reading garbage data.
So make a helper function for the "fill in pages" case, because the
exact same incomplete sequence existed in two places.
[ I should have made a squashfs branch for these things, but I didn't
intend to start doing them in the first place.
My historical connection through cramfs is why I got into looking at
these issues at all, and every time I (continue to) think it's a
one-off.
Because _this_ time is always the last time. Right? - Linus ]
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Tested-by: Willy Tarreau <w@1wt.eu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Anatoly Trosinenko reports that a corrupted squashfs image can cause a
kernel oops. It turns out that squashfs can end up being confused about
negative fragment lengths.
The regular squashfs_read_data() does check for negative lengths, but
squashfs_read_metadata() did not, and the fragment size code just
blindly trusted the on-disk value. Fix both the fragment parsing and
the metadata reading code.
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mostly direct substitution with occasional adjustment or removing
outdated comments.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.
This promise never materialized. And unlikely will.
We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE. And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.
Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.
Let's stop pretending that pages in page cache are special. They are
not.
The changes are pretty straight-forward:
- <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;
- PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};
- page_cache_get() -> get_page();
- page_cache_release() -> put_page();
This patch contains automated changes generated with coccinelle using
script below. For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.
The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.
There are few places in the code where coccinelle didn't reach. I'll
fix them manually in a separate patch. Comments and documentation also
will be addressed with the separate patch.
virtual patch
@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E
@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT
@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE
@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK
@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)
@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)
@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Restructure squashfs_readpage() splitting it into separate
functions for datablocks, fragments and sparse blocks.
Move the memcpying (from squashfs cache entry) implementation of
squashfs_readpage_block into file_cache.c
This allows different implementations to be supported.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Reviewed-by: Minchan Kim <minchan@kernel.org>
My existing email address may stop working in a month or two, so update
email to one that will continue working.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Move zlib buffer init/destroy code into separate wrapper file. Also
make zlib z_stream field a void * removing the need to include zlib.h
for most files.
Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
