Commit Graph

77924 Commits

Author SHA1 Message Date
Zhang Yi
454552d014 fs/buffer: remove bh_submit_read() helper
bh_submit_read() has no user anymore, just remove it.

Link: https://lkml.kernel.org/r/20220901133505.2510834-15-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:08 -07:00
Zhang Yi
28cf755910 ext2: replace bh_submit_read() helper with bh_read()
bh_submit_read() and the uptodate check logic in bh_uptodate_or_lock()
has been integrated in bh_read() helper, so switch to use it directly.

Link: https://lkml.kernel.org/r/20220901133505.2510834-14-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:08 -07:00
Zhang Yi
79f5978420 fs/buffer: remove ll_rw_block() helper
Now that all ll_rw_block() users has been replaced to new safe helpers,
we just remove it here.

Link: https://lkml.kernel.org/r/20220901133505.2510834-13-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:08 -07:00
Zhang Yi
6799b69831 ufs: replace ll_rw_block()
ll_rw_block() is not safe for the sync read path because it cannot
guarantee that submitting read IO if the buffer has been locked. We
could get false positive EIO after wait_on_buffer() if the buffer has
been locked by others. So stop using ll_rw_block() in ufs.

Link: https://lkml.kernel.org/r/20220901133505.2510834-12-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:07 -07:00
Zhang Yi
59a16786fa udf: replace ll_rw_block()
ll_rw_block() is not safe for the sync read path because it cannot
guarantee that submitting read IO if the buffer has been locked. We
could get false positive EIO after wait_on_buffer() if the buffer has
been locked by others. So stop using ll_rw_block(). We also switch to
new bh_readahead_batch() helper for the buffer array readahead path.

Link: https://lkml.kernel.org/r/20220901133505.2510834-11-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:07 -07:00
Zhang Yi
d554822e82 reiserfs: replace ll_rw_block()
ll_rw_block() is not safe for the sync read/write path because it cannot
guarantee that submitting read/write IO if the buffer has been locked.
We could get false positive EIO after wait_on_buffer() in read path if
the buffer has been locked by others. So stop using ll_rw_block() in
reiserfs. We also switch to new bh_readahead_batch() helper for the
buffer array readahead path.

Link: https://lkml.kernel.org/r/20220901133505.2510834-10-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:07 -07:00
Zhang Yi
54d9171d38 ocfs2: replace ll_rw_block()
ll_rw_block() is not safe for the sync read path because it cannot
guarantee that submitting read IO if the buffer has been locked. We
could get false positive EIO after wait_on_buffer() if the buffer has
been locked by others. So stop using ll_rw_block() in ocfs2.

Link: https://lkml.kernel.org/r/20220901133505.2510834-9-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:07 -07:00
Zhang Yi
6bf414a00a ntfs3: replace ll_rw_block()
ll_rw_block() is not safe for the sync read path because it cannot
guarantee that submitting read IO if the buffer has been locked. We
could get false positive EIO after wait_on_buffer() if the buffer has
been locked by others. So stop using ll_rw_block() in
ntfs_get_block_vbo().

Link: https://lkml.kernel.org/r/20220901133505.2510834-8-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:07 -07:00
Zhang Yi
8c004d1fc1 jbd2: replace ll_rw_block()
ll_rw_block() is not safe for the sync read path because it cannot
guarantee that submitting read IO if the buffer has been locked. We
could get false positive EIO after wait_on_buffer() if the buffer has
been locked by others. So stop using ll_rw_block() in
journal_get_superblock(). We also switch to new bh_readahead_batch()
for the buffer array readahead path.

Link: https://lkml.kernel.org/r/20220901133505.2510834-7-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:06 -07:00
Zhang Yi
0ed4806188 isofs: replace ll_rw_block()
ll_rw_block() is not safe for the sync read path because it cannot
guarantee that submitting read IO if the buffer has been locked. We
could get false positive EIO return from zisofs_uncompress_block() if
he buffer has been locked by others. So stop using ll_rw_block(),
switch to sync helper instead.

Link: https://lkml.kernel.org/r/20220901133505.2510834-6-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:06 -07:00
Zhang Yi
86a020cc72 gfs2: replace ll_rw_block()
ll_rw_block() is not safe for the sync read path because it cannot
guarantee that always submitting read IO if the buffer has been locked,
so stop using it. We also switch to new bh_readahead() helper for the
readahead path.

Link: https://lkml.kernel.org/r/20220901133505.2510834-5-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:06 -07:00
Zhang Yi
e7ea1129af fs/buffer: replace ll_rw_block()
ll_rw_block() is not safe for the sync IO path because it skip buffers
which has been locked by others, it could lead to false positive EIO
when submitting read IO. So stop using ll_rw_block(), switch to use new
helpers which could guarantee buffer locked and submit IO if needed.

Link: https://lkml.kernel.org/r/20220901133505.2510834-4-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:06 -07:00
Zhang Yi
fdee117ee8 fs/buffer: add some new buffer read helpers
Current ll_rw_block() helper is fragile because it assumes that locked
buffer means it's under IO which is submitted by some other who holds
the lock, it skip buffer if it failed to get the lock, so it's only
safe on the readahead path. Unfortunately, now that most filesystems
still use this helper mistakenly on the sync metadata read path. There
is no guarantee that the one who holds the buffer lock always submit IO
(e.g. buffer_migrate_folio_norefs() after commit 88dbcbb3a4 ("blkdev:
avoid migration stalls for blkdev pages"), it could lead to false
positive -EIO when submitting reading IO.

This patch add some friendly buffer read helpers to prepare replacing
ll_rw_block() and similar calls. We can only call bh_readahead_[]
helpers for the readahead paths.

Link: https://lkml.kernel.org/r/20220901133505.2510834-3-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:06 -07:00
Zhang Yi
214f879690 fs/buffer: remove __breadahead_gfp()
Patch series "fs/buffer: remove ll_rw_block()", v2.

ll_rw_block() will skip locked buffer before submitting IO, it assumes
that locked buffer means it is under IO.  This assumption is not always
true because we cannot guarantee every buffer lock path would submit IO. 
After commit 88dbcbb3a4 ("blkdev: avoid migration stalls for blkdev
pages"), buffer_migrate_folio_norefs() becomes one exceptional case, and
there may be others.  So ll_rw_block() is not safe on the sync read path,
we could get false positive EIO return value when filesystem reading
metadata.  It seems that it could be only used on the readahead path.

Unfortunately, many filesystem misuse the ll_rw_block() on the sync read
path.  This patch set just remove ll_rw_block() and add new friendly
helpers, which could prevent false positive EIO on the read metadata path.
Thanks for the suggestion from Jan, the original discussion is at [1].

 patch 1: remove unused helpers in fs/buffer.c
 patch 2: add new bh_read_[*] helpers
 patch 3-11: remove all ll_rw_block() calls in filesystems
 patch 12-14: do some leftover cleanups.

[1]. https://lore.kernel.org/linux-mm/20220825080146.2021641-1-chengzhihao1@huawei.com/


This patch (of 14):

No one use __breadahead_gfp() and sb_breadahead_unmovable() any more,
remove them.

Link: https://lkml.kernel.org/r/20220901133505.2510834-1-yi.zhang@huawei.com
Link: https://lkml.kernel.org/r/20220901133505.2510834-2-yi.zhang@huawei.com
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Evgeniy Dushistov <dushistov@mail.ru>
Cc: Heming Zhao <ocfs2-devel@oss.oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Yu Kuai <yukuai3@huawei.com>
Cc: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:06 -07:00
Vishal Moola (Oracle)
60aac486da ramfs: convert ramfs_nommu_get_unmapped_area() to use filemap_get_folios_contig()
Convert to use folios throughout.  This is in preparation for the removal
for find_get_pages_contig().  Now also supports large folios.

The initial version of this function set the page_address to be returned
after finishing all the checks.  Since folio_batches have a maximum of 15
folios, the function had to be modified to support getting and checking up
to lpages, 15 pages at a time while still returning the initial page
address.  Now the function sets ret as soon as the first batch arrives,
and updates it only if a check fails.

The physical adjacency check utilizes the page frame numbers.  The page
frame number of each folio must be nr_pages away from the first folio.

Link: https://lkml.kernel.org/r/20220824004023.77310-7-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: David Sterba <dsterb@suse.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:03 -07:00
Vishal Moola (Oracle)
24a1efb4a9 nilfs2: convert nilfs_find_uncommited_extent() to use filemap_get_folios_contig()
Convert function to use folios throughout.  This is in preparation for the
removal of find_get_pages_contig().  Now also supports large folios.

Also clean up an unnecessary if statement - pvec.pages[0]->index > index
will always evaluate to false, and filemap_get_folios_contig() returns 0
if there is no folio found at index.

Link: https://lkml.kernel.org/r/20220824004023.77310-6-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: David Sterba <dsterb@suse.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:03 -07:00
Vishal Moola (Oracle)
47d5541995 btrfs: convert process_page_range() to use filemap_get_folios_contig()
Converted function to use folios throughout.  This is in preparation for
the removal of find_get_pages_contig().  Now also supports large folios.

Since we may receive more than nr_pages pages, nr_pages may underflow. 
Since nr_pages > 0 is equivalent to index <= end_index, we replaced it
with this check instead.

Also minor comment renaming for consistency in subpage.

Link: https://lkml.kernel.org/r/20220824004023.77310-5-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: David Sterba <dsterb@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:03 -07:00
Vishal Moola (Oracle)
a75b81c3f6 btrfs: convert end_compressed_writeback() to use filemap_get_folios()
Converted function to use folios throughout.  This is in preparation for
the removal of find_get_pages_contig().  Now also supports large folios.

Since we may receive more than nr_pages pages, nr_pages may underflow. 
Since nr_pages > 0 is equivalent to index <= end_index, we replaced it
with this check instead.

Also this function does not care about the pages being contiguous so we
can just use filemap_get_folios() to be more efficient.

Link: https://lkml.kernel.org/r/20220824004023.77310-4-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterb@suse.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:03 -07:00
Vishal Moola (Oracle)
04c6b79ae4 btrfs: convert __process_pages_contig() to use filemap_get_folios_contig()
Convert to use folios throughout.  This is in preparation for the removal
of find_get_pages_contig().  Now also supports large folios.

Since we may receive more than nr_pages pages, nr_pages may underflow. 
Since nr_pages > 0 is equivalent to index <= end_index, we replaced it
with this check instead.

Link: https://lkml.kernel.org/r/20220824004023.77310-3-vishal.moola@gmail.com
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <clm@fb.com>
Cc: David Sterba <dsterb@suse.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:26:02 -07:00
Axel Rasmussen
2d5de004e0 userfaultfd: add /dev/userfaultfd for fine grained access control
Historically, it has been shown that intercepting kernel faults with
userfaultfd (thereby forcing the kernel to wait for an arbitrary amount of
time) can be exploited, or at least can make some kinds of exploits
easier.  So, in 37cd0575b8 "userfaultfd: add UFFD_USER_MODE_ONLY" we
changed things so, in order for kernel faults to be handled by
userfaultfd, either the process needs CAP_SYS_PTRACE, or this sysctl must
be configured so that any unprivileged user can do it.

In a typical implementation of a hypervisor with live migration (take
QEMU/KVM as one such example), we do indeed need to be able to handle
kernel faults.  But, both options above are less than ideal:

- Toggling the sysctl increases attack surface by allowing any
  unprivileged user to do it.

- Granting the live migration process CAP_SYS_PTRACE gives it this
  ability, but *also* the ability to "observe and control the
  execution of another process [...], and examine and change [its]
  memory and registers" (from ptrace(2)). This isn't something we need
  or want to be able to do, so granting this permission violates the
  "principle of least privilege".

This is all a long winded way to say: we want a more fine-grained way to
grant access to userfaultfd, without granting other additional permissions
at the same time.

To achieve this, add a /dev/userfaultfd misc device.  This device provides
an alternative to the userfaultfd(2) syscall for the creation of new
userfaultfds.  The idea is, any userfaultfds created this way will be able
to handle kernel faults, without the caller having any special
capabilities.  Access to this mechanism is instead restricted using e.g. 
standard filesystem permissions.

[axelrasmussen@google.com: Handle misc_register() failure properly]
  Link: https://lkml.kernel.org/r/20220819205201.658693-3-axelrasmussen@google.com
Link: https://lkml.kernel.org/r/20220808175614.3885028-3-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: Nadav Amit <namit@vmware.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dmitry V. Levin <ldv@altlinux.org>
Cc: Gleb Fotengauer-Malinovskiy <glebfm@altlinux.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhang Yi <yi.zhang@huawei.com>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:25:48 -07:00
Zach O'Keefe
a7f4e6e4c4 mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()
MADV_COLLAPSE is not coupled to the kernel-oriented sysfs THP settings[1].

hugepage_vma_check() is the authority on determining if a VMA is eligible
for THP allocation/collapse, and currently enforces the sysfs THP
settings.  Add a flag to disable these checks.  For now, only apply this
arg to anon and file, which use /sys/kernel/transparent_hugepage/enabled. 
We can expand this to shmem, which uses
/sys/kernel/transparent_hugepage/shmem_enabled, later.

Use this flag in collapse_pte_mapped_thp() where previously the VMA flags
passed to hugepage_vma_check() were OR'd with VM_HUGEPAGE to elide the
VM_HUGEPAGE check in "madvise" THP mode.  Prior to "mm: khugepaged: check
THP flag in hugepage_vma_check()", this check also didn't check "never"
THP mode.  As such, this restores the previous behavior of
collapse_pte_mapped_thp() where sysfs THP settings are ignored.  See
comment in code for justification why this is OK.

[1] https://lore.kernel.org/linux-mm/CAAa6QmQxay1_=Pmt8oCX2-Va18t44FV-Vs-WsQt_6+qBks4nZA@mail.gmail.com/

Link: https://lkml.kernel.org/r/20220706235936.2197195-8-zokeefe@google.com
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: "Souptick Joarder (HPE)" <jrdr.linux@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 20:25:45 -07:00
Linus Torvalds
b467192ec7 Seventeen hotfixes. Mostly memory management things. Ten patches are
cc:stable, addressing pre-6.0 issues.
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Merge tag 'mm-hotfixes-stable-2022-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more hotfixes from Andrew Morton:
 "Seventeen hotfixes.  Mostly memory management things.

  Ten patches are cc:stable, addressing pre-6.0 issues"

* tag 'mm-hotfixes-stable-2022-08-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  .mailmap: update Luca Ceresoli's e-mail address
  mm/mprotect: only reference swap pfn page if type match
  squashfs: don't call kmalloc in decompressors
  mm/damon/dbgfs: avoid duplicate context directory creation
  mailmap: update email address for Colin King
  asm-generic: sections: refactor memory_intersects
  bootmem: remove the vmemmap pages from kmemleak in put_page_bootmem
  ocfs2: fix freeing uninitialized resource on ocfs2_dlm_shutdown
  Revert "memcg: cleanup racy sum avoidance code"
  mm/zsmalloc: do not attempt to free IS_ERR handle
  binder_alloc: add missing mmap_lock calls when using the VMA
  mm: re-allow pinning of zero pfns (again)
  vmcoreinfo: add kallsyms_num_syms symbol
  mailmap: update Guilherme G. Piccoli's email addresses
  writeback: avoid use-after-free after removing device
  shmem: update folio if shmem_replace_page() updates the page
  mm/hugetlb: avoid corrupting page->mapping in hugetlb_mcopy_atomic_pte
2022-08-28 14:49:59 -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
Heming Zhao
550842cc60 ocfs2: fix freeing uninitialized resource on ocfs2_dlm_shutdown
After commit 0737e01de9 ("ocfs2: ocfs2_mount_volume does cleanup job
before return error"), any procedure after ocfs2_dlm_init() fails will
trigger crash when calling ocfs2_dlm_shutdown().

ie: On local mount mode, no dlm resource is initialized.  If
ocfs2_mount_volume() fails in ocfs2_find_slot(), error handling will call
ocfs2_dlm_shutdown(), then does dlm resource cleanup job, which will
trigger kernel crash.

This solution should bypass uninitialized resources in
ocfs2_dlm_shutdown().

Link: https://lkml.kernel.org/r/20220815085754.20417-1-heming.zhao@suse.com
Fixes: 0737e01de9 ("ocfs2: ocfs2_mount_volume does cleanup job before return error")
Signed-off-by: Heming Zhao <heming.zhao@suse.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-28 14:02:45 -07:00
Khazhismel Kumykov
f87904c075 writeback: avoid use-after-free after removing device
When a disk is removed, bdi_unregister gets called to stop further
writeback and wait for associated delayed work to complete.  However,
wb_inode_writeback_end() may schedule bandwidth estimation dwork after
this has completed, which can result in the timer attempting to access the
just freed bdi_writeback.

Fix this by checking if the bdi_writeback is alive, similar to when
scheduling writeback work.

Since this requires wb->work_lock, and wb_inode_writeback_end() may get
called from interrupt, switch wb->work_lock to an irqsafe lock.

Link: https://lkml.kernel.org/r/20220801155034.3772543-1-khazhy@google.com
Fixes: 45a2966fd6 ("writeback: fix bandwidth estimate for spiky workload")
Signed-off-by: Khazhismel Kumykov <khazhy@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Michael Stapelberg <stapelberg+linux@google.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-28 14:02:43 -07:00
Linus Torvalds
8379c0b31f for-6.0-rc3-tag
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Merge tag 'for-6.0-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "Fixes:

   - check that subvolume is writable when changing xattrs from security
     namespace

   - fix memory leak in device lookup helper

   - update generation of hole file extent item when merging holes

   - fix space cache corruption and potential double allocations; this
     is a rare bug but can be serious once it happens, stable backports
     and analysis tool will be provided

   - fix error handling when deleting root references

   - fix crash due to assert when attempting to cancel suspended device
     replace, add message what to do if mount fails due to missing
     replace item

  Regressions:

   - don't merge pages into bio if their page offset is not contiguous

   - don't allow large NOWAIT direct reads, this could lead to short
     reads eg. in io_uring"

* tag 'for-6.0-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: add info when mount fails due to stale replace target
  btrfs: replace: drop assert for suspended replace
  btrfs: fix silent failure when deleting root reference
  btrfs: fix space cache corruption and potential double allocations
  btrfs: don't allow large NOWAIT direct reads
  btrfs: don't merge pages into bio if their page offset is not contiguous
  btrfs: update generation of hole file extent item when merging holes
  btrfs: fix possible memory leak in btrfs_get_dev_args_from_path()
  btrfs: check if root is readonly while setting security xattr
2022-08-28 10:44:04 -07:00
Linus Torvalds
c7bb3fbc1b 5 cifs/smb3 fixes, three for stable
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Merge tag '6.0-rc2-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cfis fixes from Steve French:

 - two locking fixes (zero range, punch hole)

 - DFS 9 fix (padding), affecting some servers

 - three minor cleanup changes

* tag '6.0-rc2-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: Add helper function to check smb1+ server
  cifs: Use help macro to get the mid header size
  cifs: Use help macro to get the header preamble size
  cifs: skip extra NULL byte in filenames
  smb3: missing inode locks in punch hole
  smb3: missing inode locks in zero range
2022-08-28 10:35:16 -07:00
Zhang Xiaoxu
d291e703f4 cifs: Add helper function to check smb1+ server
SMB1 server's header_preamble_size is not 0, add use is_smb1 function
to simplify the code, no actual functional changes.

Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-24 22:30:09 -05:00
Zhang Xiaoxu
b6b3624d01 cifs: Use help macro to get the mid header size
It's better to use MID_HEADER_SIZE because the unfolded expression
too long. No actual functional changes, minor readability improvement.

Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-24 22:30:04 -05:00
Zhang Xiaoxu
9789de8bdc cifs: Use help macro to get the header preamble size
It's better to use HEADER_PREAMBLE_SIZE because the unfolded expression
too long. No actual functional changes, minor readability improvement.

Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-24 22:29:59 -05:00
Paulo Alcantara
a1d2eb51f0 cifs: skip extra NULL byte in filenames
Since commit:
 cifs: alloc_path_with_tree_prefix: do not append sep. if the path is empty
alloc_path_with_tree_prefix() function was no longer including the
trailing separator when @path is empty, although @out_len was still
assuming a path separator thus adding an extra byte to the final
filename.

This has caused mount issues in some Synology servers due to the extra
NULL byte in filenames when sending SMB2_CREATE requests with
SMB2_FLAGS_DFS_OPERATIONS set.

Fix this by checking if @path is not empty and then add extra byte for
separator.  Also, do not include any trailing NULL bytes in filename
as MS-SMB2 requires it to be 8-byte aligned and not NULL terminated.

Cc: stable@vger.kernel.org
Fixes: 7eacba3b00 ("cifs: alloc_path_with_tree_prefix: do not append sep. if the path is empty")
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-24 12:22:24 -05:00
Linus Torvalds
062d26ad0b fs.fixes.v6.0-rc3
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Merge tag 'fs.fixes.v6.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

Pull file_remove_privs() fix from Christian Brauner:
 "As part of Stefan's and Jens' work to add async buffered write
  support to xfs we refactored file_remove_privs() and added
  __file_remove_privs() to avoid calling __remove_privs() when
  IOCB_NOWAIT is passed.

  While debugging a recent performance regression report I found that
  during review we missed that commit faf99b5635 ("fs: add
  __remove_file_privs() with flags parameter") accidently changed
  behavior when dentry_needs_remove_privs() returns zero.

  Before the commit it would still call inode_has_no_xattr() setting
  the S_NOSEC bit and thereby avoiding even calling into
  dentry_needs_remove_privs() the next time this function is called.
  After that commit inode_has_no_xattr() would only be called if
  __remove_privs() had to be called.

  Restore the old behavior. This is likely the cause of the performance
  regression"

* tag 'fs.fixes.v6.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping:
  fs: __file_remove_privs(): restore call to inode_has_no_xattr()
2022-08-23 19:17:26 -07:00
Linus Torvalds
95607ad99b Thirteen fixes, almost all for MM. Seven of these are cc:stable and the
remainder fix up the changes which went into this -rc cycle.
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Merge tag 'mm-hotfixes-stable-2022-08-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "Thirteen fixes, almost all for MM.

  Seven of these are cc:stable and the remainder fix up the changes
  which went into this -rc cycle"

* tag 'mm-hotfixes-stable-2022-08-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  kprobes: don't call disarm_kprobe() for disabled kprobes
  mm/shmem: shmem_replace_page() remember NR_SHMEM
  mm/shmem: tmpfs fallocate use file_modified()
  mm/shmem: fix chattr fsflags support in tmpfs
  mm/hugetlb: support write-faults in shared mappings
  mm/hugetlb: fix hugetlb not supporting softdirty tracking
  mm/uffd: reset write protection when unregister with wp-mode
  mm/smaps: don't access young/dirty bit if pte unpresent
  mm: add DEVICE_ZONE to FOR_ALL_ZONES
  kernel/sys_ni: add compat entry for fadvise64_64
  mm/gup: fix FOLL_FORCE COW security issue and remove FOLL_COW
  Revert "zram: remove double compression logic"
  get_maintainer: add Alan to .get_maintainer.ignore
2022-08-23 13:33:08 -07:00
Anand Jain
f2c3bec215 btrfs: add info when mount fails due to stale replace target
If the replace target device reappears after the suspended replace is
cancelled, it blocks the mount operation as it can't find the matching
replace-item in the metadata. As shown below,

   BTRFS error (device sda5): replace devid present without an active replace item

To overcome this situation, the user can run the command

   btrfs device scan --forget <replace target device>

and try the mount command again. And also, to avoid repeating the issue,
superblock on the devid=0 must be wiped.

   wipefs -a device-path-to-devid=0.

This patch adds some info when this situation occurs.

Reported-by: Samuel Greiner <samuel@balkonien.org>
Link: https://lore.kernel.org/linux-btrfs/b4f62b10-b295-26ea-71f9-9a5c9299d42c@balkonien.org/T/
CC: stable@vger.kernel.org # 5.0+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-08-23 22:15:21 +02:00
Anand Jain
59a3991984 btrfs: replace: drop assert for suspended replace
If the filesystem mounts with the replace-operation in a suspended state
and try to cancel the suspended replace-operation, we hit the assert. The
assert came from the commit fe97e2e173 ("btrfs: dev-replace: replace's
scrub must not be running in suspended state") that was actually not
required. So just remove it.

 $ mount /dev/sda5 /btrfs

    BTRFS info (device sda5): cannot continue dev_replace, tgtdev is missing
    BTRFS info (device sda5): you may cancel the operation after 'mount -o degraded'

 $ mount -o degraded /dev/sda5 /btrfs <-- success.

 $ btrfs replace cancel /btrfs

    kernel: assertion failed: ret != -ENOTCONN, in fs/btrfs/dev-replace.c:1131
    kernel: ------------[ cut here ]------------
    kernel: kernel BUG at fs/btrfs/ctree.h:3750!

After the patch:

 $ btrfs replace cancel /btrfs

    BTRFS info (device sda5): suspended dev_replace from /dev/sda5 (devid 1) to <missing disk> canceled

Fixes: fe97e2e173 ("btrfs: dev-replace: replace's scrub must not be running in suspended state")
CC: stable@vger.kernel.org # 5.0+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-08-23 22:15:21 +02:00
Filipe Manana
47bf225a8d btrfs: fix silent failure when deleting root reference
At btrfs_del_root_ref(), if btrfs_search_slot() returns an error, we end
up returning from the function with a value of 0 (success). This happens
because the function returns the value stored in the variable 'err',
which is 0, while the error value we got from btrfs_search_slot() is
stored in the 'ret' variable.

So fix it by setting 'err' with the error value.

Fixes: 8289ed9f93 ("btrfs: replace the BUG_ON in btrfs_del_root_ref with proper error handling")
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-08-23 22:15:21 +02:00
Omar Sandoval
ced8ecf026 btrfs: fix space cache corruption and potential double allocations
When testing space_cache v2 on a large set of machines, we encountered a
few symptoms:

1. "unable to add free space :-17" (EEXIST) errors.
2. Missing free space info items, sometimes caught with a "missing free
   space info for X" error.
3. Double-accounted space: ranges that were allocated in the extent tree
   and also marked as free in the free space tree, ranges that were
   marked as allocated twice in the extent tree, or ranges that were
   marked as free twice in the free space tree. If the latter made it
   onto disk, the next reboot would hit the BUG_ON() in
   add_new_free_space().
4. On some hosts with no on-disk corruption or error messages, the
   in-memory space cache (dumped with drgn) disagreed with the free
   space tree.

All of these symptoms have the same underlying cause: a race between
caching the free space for a block group and returning free space to the
in-memory space cache for pinned extents causes us to double-add a free
range to the space cache. This race exists when free space is cached
from the free space tree (space_cache=v2) or the extent tree
(nospace_cache, or space_cache=v1 if the cache needs to be regenerated).
struct btrfs_block_group::last_byte_to_unpin and struct
btrfs_block_group::progress are supposed to protect against this race,
but commit d0c2f4fa55 ("btrfs: make concurrent fsyncs wait less when
waiting for a transaction commit") subtly broke this by allowing
multiple transactions to be unpinning extents at the same time.

Specifically, the race is as follows:

1. An extent is deleted from an uncached block group in transaction A.
2. btrfs_commit_transaction() is called for transaction A.
3. btrfs_run_delayed_refs() -> __btrfs_free_extent() runs the delayed
   ref for the deleted extent.
4. __btrfs_free_extent() -> do_free_extent_accounting() ->
   add_to_free_space_tree() adds the deleted extent back to the free
   space tree.
5. do_free_extent_accounting() -> btrfs_update_block_group() ->
   btrfs_cache_block_group() queues up the block group to get cached.
   block_group->progress is set to block_group->start.
6. btrfs_commit_transaction() for transaction A calls
   switch_commit_roots(). It sets block_group->last_byte_to_unpin to
   block_group->progress, which is block_group->start because the block
   group hasn't been cached yet.
7. The caching thread gets to our block group. Since the commit roots
   were already switched, load_free_space_tree() sees the deleted extent
   as free and adds it to the space cache. It finishes caching and sets
   block_group->progress to U64_MAX.
8. btrfs_commit_transaction() advances transaction A to
   TRANS_STATE_SUPER_COMMITTED.
9. fsync calls btrfs_commit_transaction() for transaction B. Since
   transaction A is already in TRANS_STATE_SUPER_COMMITTED and the
   commit is for fsync, it advances.
10. btrfs_commit_transaction() for transaction B calls
    switch_commit_roots(). This time, the block group has already been
    cached, so it sets block_group->last_byte_to_unpin to U64_MAX.
11. btrfs_commit_transaction() for transaction A calls
    btrfs_finish_extent_commit(), which calls unpin_extent_range() for
    the deleted extent. It sees last_byte_to_unpin set to U64_MAX (by
    transaction B!), so it adds the deleted extent to the space cache
    again!

This explains all of our symptoms above:

* If the sequence of events is exactly as described above, when the free
  space is re-added in step 11, it will fail with EEXIST.
* If another thread reallocates the deleted extent in between steps 7
  and 11, then step 11 will silently re-add that space to the space
  cache as free even though it is actually allocated. Then, if that
  space is allocated *again*, the free space tree will be corrupted
  (namely, the wrong item will be deleted).
* If we don't catch this free space tree corruption, it will continue
  to get worse as extents are deleted and reallocated.

The v1 space_cache is synchronously loaded when an extent is deleted
(btrfs_update_block_group() with alloc=0 calls btrfs_cache_block_group()
with load_cache_only=1), so it is not normally affected by this bug.
However, as noted above, if we fail to load the space cache, we will
fall back to caching from the extent tree and may hit this bug.

The easiest fix for this race is to also make caching from the free
space tree or extent tree synchronous. Josef tested this and found no
performance regressions.

A few extra changes fall out of this change. Namely, this fix does the
following, with step 2 being the crucial fix:

1. Factor btrfs_caching_ctl_wait_done() out of
   btrfs_wait_block_group_cache_done() to allow waiting on a caching_ctl
   that we already hold a reference to.
2. Change the call in btrfs_cache_block_group() of
   btrfs_wait_space_cache_v1_finished() to
   btrfs_caching_ctl_wait_done(), which makes us wait regardless of the
   space_cache option.
3. Delete the now unused btrfs_wait_space_cache_v1_finished() and
   space_cache_v1_done().
4. Change btrfs_cache_block_group()'s `int load_cache_only` parameter to
   `bool wait` to more accurately describe its new meaning.
5. Change a few callers which had a separate call to
   btrfs_wait_block_group_cache_done() to use wait = true instead.
6. Make btrfs_wait_block_group_cache_done() static now that it's not
   used outside of block-group.c anymore.

Fixes: d0c2f4fa55 ("btrfs: make concurrent fsyncs wait less when waiting for a transaction commit")
CC: stable@vger.kernel.org # 5.12+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-08-23 22:13:54 +02:00
David Howells
ba0803050d smb3: missing inode locks in punch hole
smb3 fallocate punch hole was not grabbing the inode or filemap_invalidate
locks so could have race with pagemap reinstantiating the page.

Cc: stable@vger.kernel.org
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-23 03:15:27 -05:00
David Howells
c919c164fc smb3: missing inode locks in zero range
smb3 fallocate zero range was not grabbing the inode or filemap_invalidate
locks so could have race with pagemap reinstantiating the page.

Cc: stable@vger.kernel.org
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-08-23 01:09:08 -05:00
Linus Torvalds
072e51356c NFS client bugfixes for Linux 6.0
Highlights include:
 
 Stable fixes
 - NFS: Fix another fsync() issue after a server reboot
 
 Bugfixes
 - NFS: unlink/rmdir shouldn't call d_delete() twice on ENOENT
 - NFS: Fix missing unlock in nfs_unlink()
 - Add sanity checking of the file type used by __nfs42_ssc_open
 - Fix a case where we're failing to set task->tk_rpc_status
 
 Cleanups
 - Remove the flag NFS_CONTEXT_RESEND_WRITES that got obsoleted by the
   fsync() fix
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Merge tag 'nfs-for-5.20-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client fixes from Trond Myklebust:
"Stable fixes:
   - NFS: Fix another fsync() issue after a server reboot

  Bugfixes:
   - NFS: unlink/rmdir shouldn't call d_delete() twice on ENOENT
   - NFS: Fix missing unlock in nfs_unlink()
   - Add sanity checking of the file type used by __nfs42_ssc_open
   - Fix a case where we're failing to set task->tk_rpc_status

  Cleanups:
   - Remove the NFS_CONTEXT_RESEND_WRITES flag that got obsoleted by the
     fsync() fix"

* tag 'nfs-for-5.20-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: RPC level errors should set task->tk_rpc_status
  NFSv4.2 fix problems with __nfs42_ssc_open
  NFS: unlink/rmdir shouldn't call d_delete() twice on ENOENT
  NFS: Cleanup to remove unused flag NFS_CONTEXT_RESEND_WRITES
  NFS: Remove a bogus flag setting in pnfs_write_done_resend_to_mds
  NFS: Fix another fsync() issue after a server reboot
  NFS: Fix missing unlock in nfs_unlink()
2022-08-22 11:40:01 -07:00
Linus Torvalds
d3cd67d671 fs.idmapped.fixes.v6.0-rc3
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Merge tag 'fs.idmapped.fixes.v6.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping

Pull idmapping fixes from Christian Brauner:

 - Since Seth joined as co-maintainer for idmapped mounts we decided to
   use a shared git tree. Konstantin suggested we use vfs/idmapping.git
   on kernel.org under the vfs/ namespace. So this updates the tree in
   the maintainers file.

 - Ensure that POSIX ACLs checking, getting, and setting works correctly
   for filesystems mountable with a filesystem idmapping that want to
   support idmapped mounts.

   Since no filesystems mountable with an fs_idmapping do yet support
   idmapped mounts there is no problem. But this could change in the
   future, so add a check to refuse to create idmapped mounts when the
   mounter is not privileged over the mount's idmapping.

 - Check that caller is privileged over the idmapping that will be
   attached to a mount.

   Currently no FS_USERNS_MOUNT filesystems support idmapped mounts,
   thus this is not a problem as only CAP_SYS_ADMIN in init_user_ns is
   allowed to set up idmapped mounts. But this could change in the
   future, so add a check to refuse to create idmapped mounts when the
   mounter is not privileged over the mount's idmapping.

 - Fix POSIX ACLs for ntfs3. While looking at our current POSIX ACL
   handling in the context of some overlayfs work I went through a range
   of other filesystems checking how they handle them currently and
   encountered a few bugs in ntfs3.

   I've sent this some time ago and the fixes haven't been picked up
   even though the pull request for other ntfs3 fixes got sent after.
   This should really be fixed as right now POSIX ACLs are broken in
   certain circumstances for ntfs3.

* tag 'fs.idmapped.fixes.v6.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/idmapping:
  ntfs: fix acl handling
  fs: require CAP_SYS_ADMIN in target namespace for idmapped mounts
  MAINTAINERS: update idmapping tree
  acl: handle idmapped mounts for idmapped filesystems
2022-08-22 11:33:02 -07:00
Linus Torvalds
b20ee4813f File locking bugfix for v6.0
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Merge tag 'filelock-v6.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

Pull file locking fix from Jeff Layton:
 "Just a single patch for a bugfix in the flock() codepath, introduced
  by a patch that went in recently"

* tag 'filelock-v6.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  locks: Fix dropped call to ->fl_release_private()
2022-08-22 10:40:09 -07:00
Josef Bacik
79d3d1d12e btrfs: don't allow large NOWAIT direct reads
Dylan and Jens reported a problem where they had an io_uring test that
was returning short reads, and bisected it to ee5b46a353 ("btrfs:
increase direct io read size limit to 256 sectors").

The root cause is their test was doing larger reads via io_uring with
NOWAIT and async.  This was triggering a page fault during the direct
read, however the first page was able to work just fine and thus we
submitted a 4k read for a larger iocb.

Btrfs allows for partial IO's in this case specifically because we don't
allow page faults, and thus we'll attempt to do any io that we can,
submit what we could, come back and fault in the rest of the range and
try to do the remaining IO.

However for !is_sync_kiocb() we'll call ->ki_complete() as soon as the
partial dio is done, which is incorrect.  In the sync case we can exit
the iomap code, submit more io's, and return with the amount of IO we
were able to complete successfully.

We were always doing short reads in this case, but for NOWAIT we were
getting saved by the fact that we were limiting direct reads to
sectorsize, and if we were larger than that we would return EAGAIN.

Fix the regression by simply returning EAGAIN in the NOWAIT case with
larger reads, that way io_uring can retry and get the larger IO and have
the fault logic handle everything properly.

This still leaves the AIO short read case, but that existed before this
change.  The way to properly fix this would be to handle partial iocb
completions, but that's a lot of work, for now deal with the regression
in the most straightforward way possible.

Reported-by: Dylan Yudaken <dylany@fb.com>
Fixes: ee5b46a353 ("btrfs: increase direct io read size limit to 256 sectors")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-08-22 18:08:07 +02:00
Qu Wenruo
4a445b7b61 btrfs: don't merge pages into bio if their page offset is not contiguous
[BUG]
Zygo reported on latest development branch, he could hit
ASSERT()/BUG_ON() caused crash when doing RAID5 recovery (intentionally
corrupt one disk, and let btrfs to recover the data during read/scrub).

And The following minimal reproducer can cause extent state leakage at
rmmod time:

  mkfs.btrfs -f -d raid5 -m raid5 $dev1 $dev2 $dev3 -b 1G > /dev/null
  mount $dev1 $mnt
  fsstress -w -d $mnt -n 25 -s 1660807876
  sync
  fssum -A -f -w /tmp/fssum.saved $mnt
  umount $mnt

  # Wipe the dev1 but keeps its super block
  xfs_io -c "pwrite -S 0x0 1m 1023m" $dev1
  mount $dev1 $mnt
  fssum -r /tmp/fssum.saved $mnt > /dev/null
  umount $mnt
  rmmod btrfs

This will lead to the following extent states leakage:

  BTRFS: state leak: start 499712 end 503807 state 5 in tree 1 refs 1
  BTRFS: state leak: start 495616 end 499711 state 5 in tree 1 refs 1
  BTRFS: state leak: start 491520 end 495615 state 5 in tree 1 refs 1
  BTRFS: state leak: start 487424 end 491519 state 5 in tree 1 refs 1
  BTRFS: state leak: start 483328 end 487423 state 5 in tree 1 refs 1
  BTRFS: state leak: start 479232 end 483327 state 5 in tree 1 refs 1
  BTRFS: state leak: start 475136 end 479231 state 5 in tree 1 refs 1
  BTRFS: state leak: start 471040 end 475135 state 5 in tree 1 refs 1

[CAUSE]
Since commit 7aa51232e2 ("btrfs: pass a btrfs_bio to
btrfs_repair_one_sector"), we always use btrfs_bio->file_offset to
determine the file offset of a page.

But that usage assume that, one bio has all its page having a continuous
page offsets.

Unfortunately that's not true, btrfs only requires the logical bytenr
contiguous when assembling its bios.

From above script, we have one bio looks like this:

  fssum-27671  submit_one_bio: bio logical=217739264 len=36864
  fssum-27671  submit_one_bio:   r/i=5/261 page_offset=466944 <<<
  fssum-27671  submit_one_bio:   r/i=5/261 page_offset=724992 <<<
  fssum-27671  submit_one_bio:   r/i=5/261 page_offset=729088
  fssum-27671  submit_one_bio:   r/i=5/261 page_offset=733184
  fssum-27671  submit_one_bio:   r/i=5/261 page_offset=737280
  fssum-27671  submit_one_bio:   r/i=5/261 page_offset=741376
  fssum-27671  submit_one_bio:   r/i=5/261 page_offset=745472
  fssum-27671  submit_one_bio:   r/i=5/261 page_offset=749568
  fssum-27671  submit_one_bio:   r/i=5/261 page_offset=753664

Note that the 1st and the 2nd page has non-contiguous page offsets.

This means, at repair time, we will have completely wrong file offset
passed in:

   kworker/u32:2-19927  btrfs_repair_one_sector: r/i=5/261 page_off=729088 file_off=475136 bio_offset=8192

Since the file offset is incorrect, we latter incorrectly set the extent
states, and no way to really release them.

Thus later it causes the leakage.

In fact, this can be even worse, since the file offset is incorrect, we
can hit cases like the incorrect file offset belongs to a HOLE, and
later cause btrfs_num_copies() to trigger error, finally hit
BUG_ON()/ASSERT() later.

[FIX]
Add an extra condition in btrfs_bio_add_page() for uncompressed IO.

Now we will have more strict requirement for bio pages:

- They should all have the same mapping
  (the mapping check is already implied by the call chain)

- Their logical bytenr should be adjacent
  This is the same as the old condition.

- Their page_offset() (file offset) should be adjacent
  This is the new check.
  This would result a slightly increased amount of bios from btrfs
  (needs holes and inside the same stripe boundary to trigger).

  But this would greatly reduce the confusion, as it's pretty common
  to assume a btrfs bio would only contain continuous page cache.

Later we may need extra cleanups, as we no longer needs to handle gaps
between page offsets in endio functions.

Currently this should be the minimal patch to fix commit 7aa51232e2
("btrfs: pass a btrfs_bio to btrfs_repair_one_sector").

Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Fixes: 7aa51232e2 ("btrfs: pass a btrfs_bio to btrfs_repair_one_sector")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-08-22 18:06:58 +02:00
Filipe Manana
e6e3dec6c3 btrfs: update generation of hole file extent item when merging holes
When punching a hole into a file range that is adjacent with a hole and we
are not using the no-holes feature, we expand the range of the adjacent
file extent item that represents a hole, to save metadata space.

However we don't update the generation of hole file extent item, which
means a full fsync will not log that file extent item if the fsync happens
in a later transaction (since commit 7f30c07288 ("btrfs: stop copying
old file extents when doing a full fsync")).

For example, if we do this:

    $ mkfs.btrfs -f -O ^no-holes /dev/sdb
    $ mount /dev/sdb /mnt
    $ xfs_io -f -c "pwrite -S 0xab 2M 2M" /mnt/foobar
    $ sync

We end up with 2 file extent items in our file:

1) One that represents the hole for the file range [0, 2M), with a
   generation of 7;

2) Another one that represents an extent covering the range [2M, 4M).

After that if we do the following:

    $ xfs_io -c "fpunch 2M 2M" /mnt/foobar

We end up with a single file extent item in the file, which represents a
hole for the range [0, 4M) and with a generation of 7 - because we end
dropping the data extent for range [2M, 4M) and then update the file
extent item that represented the hole at [0, 2M), by increasing
length from 2M to 4M.

Then doing a full fsync and power failing:

    $ xfs_io -c "fsync" /mnt/foobar
    <power failure>

will result in the full fsync not logging the file extent item that
represents the hole for the range [0, 4M), because its generation is 7,
which is lower than the generation of the current transaction (8).
As a consequence, after mounting again the filesystem (after log replay),
the region [2M, 4M) does not have a hole, it still points to the
previous data extent.

So fix this by always updating the generation of existing file extent
items representing holes when we merge/expand them. This solves the
problem and it's the same approach as when we merge prealloc extents that
got written (at btrfs_mark_extent_written()). Setting the generation to
the current transaction's generation is also what we do when merging
the new hole extent map with the previous one or the next one.

A test case for fstests, covering both cases of hole file extent item
merging (to the left and to the right), will be sent soon.

Fixes: 7f30c07288 ("btrfs: stop copying old file extents when doing a full fsync")
CC: stable@vger.kernel.org # 5.18+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-08-22 18:06:42 +02:00
Zixuan Fu
9ea0106a7a btrfs: fix possible memory leak in btrfs_get_dev_args_from_path()
In btrfs_get_dev_args_from_path(), btrfs_get_bdev_and_sb() can fail if
the path is invalid. In this case, btrfs_get_dev_args_from_path()
returns directly without freeing args->uuid and args->fsid allocated
before, which causes memory leak.

To fix these possible leaks, when btrfs_get_bdev_and_sb() fails,
btrfs_put_dev_args_from_path() is called to clean up the memory.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Fixes: faa775c41d ("btrfs: add a btrfs_get_dev_args_from_path helper")
CC: stable@vger.kernel.org # 5.16
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Zixuan Fu <r33s3n6@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-08-22 18:06:33 +02:00
Goldwyn Rodrigues
b51111271b btrfs: check if root is readonly while setting security xattr
For a filesystem which has btrfs read-only property set to true, all
write operations including xattr should be denied. However, security
xattr can still be changed even if btrfs ro property is true.

This happens because xattr_permission() does not have any restrictions
on security.*, system.*  and in some cases trusted.* from VFS and
the decision is left to the underlying filesystem. See comments in
xattr_permission() for more details.

This patch checks if the root is read-only before performing the set
xattr operation.

Testcase:

  DEV=/dev/vdb
  MNT=/mnt

  mkfs.btrfs -f $DEV
  mount $DEV $MNT
  echo "file one" > $MNT/f1

  setfattr -n "security.one" -v 2 $MNT/f1
  btrfs property set /mnt ro true

  setfattr -n "security.one" -v 1 $MNT/f1

  umount $MNT

CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2022-08-22 18:06:30 +02:00
Christian Brauner
0c3bc7899e
ntfs: fix acl handling
While looking at our current POSIX ACL handling in the context of some
overlayfs work I went through a range of other filesystems checking how they
handle them currently and encountered ntfs3.

The posic_acl_{from,to}_xattr() helpers always need to operate on the
filesystem idmapping. Since ntfs3 can only be mounted in the initial user
namespace the relevant idmapping is init_user_ns.

The posix_acl_{from,to}_xattr() helpers are concerned with translating between
the kernel internal struct posix_acl{_entry} and the uapi struct
posix_acl_xattr_{header,entry} and the kernel internal data structure is cached
filesystem wide.

Additional idmappings such as the caller's idmapping or the mount's idmapping
are handled higher up in the VFS. Individual filesystems usually do not need to
concern themselves with these.

The posix_acl_valid() helper is concerned with checking whether the values in
the kernel internal struct posix_acl can be represented in the filesystem's
idmapping. IOW, if they can be written to disk. So this helper too needs to
take the filesystem's idmapping.

Fixes: be71b5cba2 ("fs/ntfs3: Add attrib operations")
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: ntfs3@lists.linux.dev
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
2022-08-22 12:52:23 +02:00
Linus Torvalds
367bcbc5b5 5 cifs/smb3 fixes, one for stable
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Merge tag '6.0-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs client fixes from Steve French:

 - memory leak fix

 - two small cleanups

 - trivial strlcpy removal

 - update missing entry for cifs headers in MAINTAINERS file

* tag '6.0-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: move from strlcpy with unused retval to strscpy
  cifs: Fix memory leak on the deferred close
  cifs: remove useless parameter 'is_fsctl' from SMB2_ioctl()
  cifs: remove unused server parameter from calc_smb_size()
  cifs: missing directory in MAINTAINERS file
2022-08-21 10:21:16 -07:00
Peter Xu
f369b07c86 mm/uffd: reset write protection when unregister with wp-mode
The motivation of this patch comes from a recent report and patchfix from
David Hildenbrand on hugetlb shared handling of wr-protected page [1].

With the reproducer provided in commit message of [1], one can leverage
the uffd-wp lazy-reset of ptes to trigger a hugetlb issue which can affect
not only the attacker process, but also the whole system.

The lazy-reset mechanism of uffd-wp was used to make unregister faster,
meanwhile it has an assumption that any leftover pgtable entries should
only affect the process on its own, so not only the user should be aware
of anything it does, but also it should not affect outside of the process.

But it seems that this is not true, and it can also be utilized to make
some exploit easier.

So far there's no clue showing that the lazy-reset is important to any
userfaultfd users because normally the unregister will only happen once
for a specific range of memory of the lifecycle of the process.

Considering all above, what this patch proposes is to do explicit pte
resets when unregister an uffd region with wr-protect mode enabled.

It should be the same as calling ioctl(UFFDIO_WRITEPROTECT, wp=false)
right before ioctl(UFFDIO_UNREGISTER) for the user.  So potentially it'll
make the unregister slower.  From that pov it's a very slight abi change,
but hopefully nothing should break with this change either.

Regarding to the change itself - core of uffd write [un]protect operation
is moved into a separate function (uffd_wp_range()) and it is reused in
the unregister code path.

Note that the new function will not check for anything, e.g.  ranges or
memory types, because they should have been checked during the previous
UFFDIO_REGISTER or it should have failed already.  It also doesn't check
mmap_changing because we're with mmap write lock held anyway.

I added a Fixes upon introducing of uffd-wp shmem+hugetlbfs because that's
the only issue reported so far and that's the commit David's reproducer
will start working (v5.19+).  But the whole idea actually applies to not
only file memories but also anonymous.  It's just that we don't need to
fix anonymous prior to v5.19- because there's no known way to exploit.

IOW, this patch can also fix the issue reported in [1] as the patch 2 does.

[1] https://lore.kernel.org/all/20220811103435.188481-3-david@redhat.com/

Link: https://lkml.kernel.org/r/20220811201340.39342-1-peterx@redhat.com
Fixes: b1f9e87686 ("mm/uffd: enable write protection for shmem & hugetlbfs")
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-08-20 15:17:45 -07:00