[ Upstream commit b1fe686a765e6c0d71811d825b5a1585a202b777 ]

The root inode is assumed to be always hashed.  Do not unhash the root
inode even if it is marked BAD.

Fixes: 5d069dbe8aaf ("fuse: fix bad inode")
Cc: <stable@vger.kernel.org> # v5.11
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 68ca1b49e430f6534d0774a94147a823e3b8b26e ]

The root inode has a fixed nodeid and generation (1, 0).

Prior to the commit 15db16837a35 ("fuse: fix illegal access to inode with
reused nodeid") generation number on lookup was ignored.  After this commit
lookup with the wrong generation number resulted in the inode being
unhashed.  This is correct for non-root inodes, but replacing the root
inode is wrong and results in weird behavior.

Fix by reverting to the old behavior if ignoring the generation for the
root inode, but issuing a warning in dmesg.

Reported-by: Antonio SJ Musumeci <trapexit@spawn.link>
Closes: https://lore.kernel.org/all/CAOQ4uxhek5ytdN8Yz2tNEOg5ea4NkBb4nk0FGPjPk_9nz-VG3g@mail.gmail.com/
Fixes: 15db16837a35 ("fuse: fix illegal access to inode with reused nodeid")
Cc: <stable@vger.kernel.org> # v5.14
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 82e081aebe4d9c26e196c8260005cc4762b57a5d ]

fuse_do_statx() was added with the wrong helper.

Fixes: d3045530bdd2 ("fuse: implement statx")
Cc: <stable@vger.kernel.org> # v6.6
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

[ Upstream commit 9511176bbaee0ac60ecc84e7b01cf5972a59ea17 ]

There were multiple issues with direct_io_allow_mmap:

 - fuse_link_write_file() was missing, resulting in warnings in
   fuse_write_file_get() and EIO from msync()

 - "vma->vm_ops = &fuse_file_vm_ops" was not set, but especially
   fuse_page_mkwrite is needed.

The semantics of invalidate_inode_pages2() is so far not clearly defined in
fuse_file_mmap.  It dates back to commit 3121bfe76311 ("fuse: fix
"direct_io" private mmap") Though, as direct_io_allow_mmap is a new
feature, that was for MAP_PRIVATE only.  As invalidate_inode_pages2() is
calling into fuse_launder_folio() and writes out dirty pages, it should be
safe to call invalidate_inode_pages2 for MAP_PRIVATE and MAP_SHARED as
well.

Cc: Hao Xu <howeyxu@tencent.com>
Cc: stable@vger.kernel.org
Fixes: e78662e818f9 ("fuse: add a new fuse init flag to relax restrictions in no cache mode")
Signed-off-by: Bernd Schubert <bschubert@ddn.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

commit 7f8ed28d1401320bcb02dda81b3c23ab2dc5a6d8 upstream.

fuse_dax_conn_free() will be called when fuse_fill_super_common() fails
after fuse_dax_conn_alloc(). Then deactivate_locked_super() in
virtio_fs_get_tree() will call virtio_kill_sb() to release the discarded
superblock. This will call fuse_dax_conn_free() again in fuse_conn_put(),
resulting in a possible double free.

Fixes: 1dd539577c42 ("virtiofs: add a mount option to enable dax")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Cc: <stable@vger.kernel.org> # v5.10
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 3f29f1c336c0e8a4bec52f1e5217f88835553e5b upstream.

The new fuse init flag FUSE_DIRECT_IO_ALLOW_MMAP breaks assumptions made by
FOPEN_PARALLEL_DIRECT_WRITES and causes test generic/095 to hit
BUG_ON(fi->writectr < 0) assertions in fuse_set_nowrite():

generic/095 5s ...
  kernel BUG at fs/fuse/dir.c:1756!
...
  ? fuse_set_nowrite+0x3d/0xdd
  ? do_raw_spin_unlock+0x88/0x8f
  ? _raw_spin_unlock+0x2d/0x43
  ? fuse_range_is_writeback+0x71/0x84
  fuse_sync_writes+0xf/0x19
  fuse_direct_io+0x167/0x5bd
  fuse_direct_write_iter+0xf0/0x146

Auto disable FOPEN_PARALLEL_DIRECT_WRITES when server negotiated
FUSE_DIRECT_IO_ALLOW_MMAP.

Fixes: e78662e818f9 ("fuse: add a new fuse init flag to relax restrictions in no cache mode")
Cc: <stable@vger.kernel.org> # v6.6
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c4d361f66ac91db8fc65061a9671682f61f4ca9d upstream.

Fuse submounts do not perform a lookup for the nodeid that they inherit
from their parent.  Instead, the code decrements the nlookup on the
submount's fuse_inode when it is instantiated, and no forget is
performed when a submount root is evicted.

Trouble arises when the submount's parent is evicted despite the
submount itself being in use.  In this author's case, the submount was
in a container and deatched from the initial mount namespace via a
MNT_DEATCH operation.  When memory pressure triggered the shrinker, the
inode from the parent was evicted, which triggered enough forgets to
render the submount's nodeid invalid.

Since submounts should still function, even if their parent goes away,
solve this problem by sharing refcounted state between the parent and
its submount.  When all of the references on this shared state reach
zero, it's safe to forget the final lookup of the fuse nodeid.

Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Cc: stable@vger.kernel.org
Fixes: 1866d779d5d2 ("fuse: Allow fuse_fill_super_common() for submounts")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit c55e0a55b165202f18cbc4a20650d2e1becd5507 upstream.

Although DIRECT_IO_RELAX's initial usage is to allow shared mmap, its
description indicates a purpose of reducing memory footprint. This
may imply that it could be further used to relax other DIRECT_IO
operations in the future.

Replace it with a flag DIRECT_IO_ALLOW_MMAP which does only one thing,
allow shared mmap of DIRECT_IO files while still bypassing the cache
on regular reads and writes.

[Miklos] Also Keep DIRECT_IO_RELAX definition for backward compatibility.

Signed-off-by: Tyler Fanelli <tfanelli@redhat.com>
Fixes: e78662e818f9 ("fuse: add a new fuse init flag to relax restrictions in no cache mode")
Cc: <stable@vger.kernel.org> # v6.6
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull fuse updates from Miklos Szeredi:

 - Revert non-waiting FLUSH due to a regression

 - Fix a lookup counter leak in readdirplus

 - Add an option to allow shared mmaps in no-cache mode

 - Add btime support and statx intrastructure to the protocol

 - Invalidate positive/negative dentry on failed create/delete

* tag 'fuse-update-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: conditionally fill kstat in fuse_do_statx()
  fuse: invalidate dentry on EEXIST creates or ENOENT deletes
  fuse: cache btime
  fuse: implement statx
  fuse: add ATTR_TIMEOUT macro
  fuse: add STATX request
  fuse: handle empty request_mask in statx
  fuse: write back dirty pages before direct write in direct_io_relax mode
  fuse: add a new fuse init flag to relax restrictions in no cache mode
  fuse: invalidate page cache pages before direct write
  fuse: nlookup missing decrement in fuse_direntplus_link
  Revert "fuse: in fuse_flush only wait if someone wants the return code"

Pull MM updates from Andrew Morton:

 - Some swap cleanups from Ma Wupeng ("fix WARN_ON in
   add_to_avail_list")

 - Peter Xu has a series (mm/gup: Unify hugetlb, speed up thp") which
   reduces the special-case code for handling hugetlb pages in GUP. It
   also speeds up GUP handling of transparent hugepages.

 - Peng Zhang provides some maple tree speedups ("Optimize the fast path
   of mas_store()").

 - Sergey Senozhatsky has improved te performance of zsmalloc during
   compaction (zsmalloc: small compaction improvements").

 - Domenico Cerasuolo has developed additional selftest code for zswap
   ("selftests: cgroup: add zswap test program").

 - xu xin has doe some work on KSM's handling of zero pages. These
   changes are mainly to enable the user to better understand the
   effectiveness of KSM's treatment of zero pages ("ksm: support
   tracking KSM-placed zero-pages").

 - Jeff Xu has fixes the behaviour of memfd's
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED sysctl ("mm/memfd: fix sysctl
   MEMFD_NOEXEC_SCOPE_NOEXEC_ENFORCED").

 - David Howells has fixed an fscache optimization ("mm, netfs, fscache:
   Stop read optimisation when folio removed from pagecache").

 - Axel Rasmussen has given userfaultfd the ability to simulate memory
   poisoning ("add UFFDIO_POISON to simulate memory poisoning with
   UFFD").

 - Miaohe Lin has contributed some routine maintenance work on the
   memory-failure code ("mm: memory-failure: remove unneeded PageHuge()
   check").

 - Peng Zhang has contributed some maintenance work on the maple tree
   code ("Improve the validation for maple tree and some cleanup").

 - Hugh Dickins has optimized the collapsing of shmem or file pages into
   THPs ("mm: free retracted page table by RCU").

 - Jiaqi Yan has a patch series which permits us to use the healthy
   subpages within a hardware poisoned huge page for general purposes
   ("Improve hugetlbfs read on HWPOISON hugepages").

 - Kemeng Shi has done some maintenance work on the pagetable-check code
   ("Remove unused parameters in page_table_check").

 - More folioification work from Matthew Wilcox ("More filesystem folio
   conversions for 6.6"), ("Followup folio conversions for zswap"). And
   from ZhangPeng ("Convert several functions in page_io.c to use a
   folio").

 - page_ext cleanups from Kemeng Shi ("minor cleanups for page_ext").

 - Baoquan He has converted some architectures to use the
   GENERIC_IOREMAP ioremap()/iounmap() code ("mm: ioremap: Convert
   architectures to take GENERIC_IOREMAP way").

 - Anshuman Khandual has optimized arm64 tlb shootdown ("arm64: support
   batched/deferred tlb shootdown during page reclamation/migration").

 - Better maple tree lockdep checking from Liam Howlett ("More strict
   maple tree lockdep"). Liam also developed some efficiency
   improvements ("Reduce preallocations for maple tree").

 - Cleanup and optimization to the secondary IOMMU TLB invalidation,
   from Alistair Popple ("Invalidate secondary IOMMU TLB on permission
   upgrade").

 - Ryan Roberts fixes some arm64 MM selftest issues ("selftests/mm fixes
   for arm64").

 - Kemeng Shi provides some maintenance work on the compaction code
   ("Two minor cleanups for compaction").

 - Some reduction in mmap_lock pressure from Matthew Wilcox ("Handle
   most file-backed faults under the VMA lock").

 - Aneesh Kumar contributes code to use the vmemmap optimization for DAX
   on ppc64, under some circumstances ("Add support for DAX vmemmap
   optimization for ppc64").

 - page-ext cleanups from Kemeng Shi ("add page_ext_data to get client
   data in page_ext"), ("minor cleanups to page_ext header").

 - Some zswap cleanups from Johannes Weiner ("mm: zswap: three
   cleanups").

 - kmsan cleanups from ZhangPeng ("minor cleanups for kmsan").

 - VMA handling cleanups from Kefeng Wang ("mm: convert to
   vma_is_initial_heap/stack()").

 - DAMON feature work from SeongJae Park ("mm/damon/sysfs-schemes:
   implement DAMOS tried total bytes file"), ("Extend DAMOS filters for
   address ranges and DAMON monitoring targets").

 - Compaction work from Kemeng Shi ("Fixes and cleanups to compaction").

 - Liam Howlett has improved the maple tree node replacement code
   ("maple_tree: Change replacement strategy").

 - ZhangPeng has a general code cleanup - use the K() macro more widely
   ("cleanup with helper macro K()").

 - Aneesh Kumar brings memmap-on-memory to ppc64 ("Add support for
   memmap on memory feature on ppc64").

 - pagealloc cleanups from Kemeng Shi ("Two minor cleanups for pcp list
   in page_alloc"), ("Two minor cleanups for get pageblock
   migratetype").

 - Vishal Moola introduces a memory descriptor for page table tracking,
   "struct ptdesc" ("Split ptdesc from struct page").

 - memfd selftest maintenance work from Aleksa Sarai ("memfd: cleanups
   for vm.memfd_noexec").

 - MM include file rationalization from Hugh Dickins ("arch: include
   asm/cacheflush.h in asm/hugetlb.h").

 - THP debug output fixes from Hugh Dickins ("mm,thp: fix sloppy text
   output").

 - kmemleak improvements from Xiaolei Wang ("mm/kmemleak: use
   object_cache instead of kmemleak_initialized").

 - More folio-related cleanups from Matthew Wilcox ("Remove _folio_dtor
   and _folio_order").

 - A VMA locking scalability improvement from Suren Baghdasaryan
   ("Per-VMA lock support for swap and userfaults").

 - pagetable handling cleanups from Matthew Wilcox ("New page table
   range API").

 - A batch of swap/thp cleanups from David Hildenbrand ("mm/swap: stop
   using page->private on tail pages for THP_SWAP + cleanups").

 - Cleanups and speedups to the hugetlb fault handling from Matthew
   Wilcox ("Change calling convention for ->huge_fault").

 - Matthew Wilcox has also done some maintenance work on the MM
   subsystem documentation ("Improve mm documentation").

* tag 'mm-stable-2023-08-28-18-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (489 commits)
  maple_tree: shrink struct maple_tree
  maple_tree: clean up mas_wr_append()
  secretmem: convert page_is_secretmem() to folio_is_secretmem()
  nios2: fix flush_dcache_page() for usage from irq context
  hugetlb: add documentation for vma_kernel_pagesize()
  mm: add orphaned kernel-doc to the rst files.
  mm: fix clean_record_shared_mapping_range kernel-doc
  mm: fix get_mctgt_type() kernel-doc
  mm: fix kernel-doc warning from tlb_flush_rmaps()
  mm: remove enum page_entry_size
  mm: allow ->huge_fault() to be called without the mmap_lock held
  mm: move PMD_ORDER to pgtable.h
  mm: remove checks for pte_index
  memcg: remove duplication detection for mem_cgroup_uncharge_swap
  mm/huge_memory: work on folio->swap instead of page->private when splitting folio
  mm/swap: inline folio_set_swap_entry() and folio_swap_entry()
  mm/swap: use dedicated entry for swap in folio
  mm/swap: stop using page->private on tail pages for THP_SWAP
  selftests/mm: fix WARNING comparing pointer to 0
  selftests: cgroup: fix test_kmem_memcg_deletion kernel mem check
  ...