| Age | Commit message (Collapse) | Author | Files | Lines |
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Pull NFS client fixes from Trond Myklebust:
- fix a use after free in nfs_direct_join_group() (Cc: stable)
- fix sysfs server name memory leak
- fix lock recovery hang in NFSv4.0
- fix page free in the error path for nfs42_proc_getxattr() and
__nfs4_get_acl_uncached()
- SUNRPC/rdma: fix receive buffer dma-mapping after a server disconnect
* tag 'nfs-for-6.5-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
xprtrdma: Remap Receive buffers after a reconnect
NFSv4: fix out path in __nfs4_get_acl_uncached
NFSv4.2: fix error handling in nfs42_proc_getxattr
NFS: Fix sysfs server name memory leak
NFS: Fix a use after free in nfs_direct_join_group()
NFSv4: Fix dropped lock for racing OPEN and delegation return
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A compiler may see the collision with the toupper() defined in ctype.h:
fs/affs/namei.c:159:19: warning: unused variable 'toupper' [-Wunused-variable]
159 | toupper_t toupper = affs_get_toupper(sb);
To prevent this from happening, rename toupper local variable to fn.
Initially this had been introduced by 24579a881513 ("v2.4.3.5 -> v2.4.3.6")
in the history.git by history group.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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If the filesystem implements migrate_folio and writepages, there is
no need for a writepage implementation.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When doing a relocation, there is a chance that at the time of
btrfs_reloc_clone_csums(), there is no checksum for the corresponding
region.
In this case, btrfs_finish_ordered_zoned()'s sum points to an invalid item
and so ordered_extent's logical is set to some invalid value. Then,
btrfs_lookup_block_group() in btrfs_zone_finish_endio() failed to find a
block group and will hit an assert or a null pointer dereference as
following.
This can be reprodcued by running btrfs/028 several times (e.g, 4 to 16
times) with a null_blk setup. The device's zone size and capacity is set to
32 MB and the storage size is set to 5 GB on my setup.
KASAN: null-ptr-deref in range [0x0000000000000088-0x000000000000008f]
CPU: 6 PID: 3105720 Comm: kworker/u16:13 Tainted: G W 6.5.0-rc6-kts+ #1
Hardware name: Supermicro Super Server/X10SRL-F, BIOS 2.0 12/17/2015
Workqueue: btrfs-endio-write btrfs_work_helper [btrfs]
RIP: 0010:btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs]
Code: 41 54 49 89 fc 55 48 89 f5 53 e8 57 7d fc ff 48 8d b8 88 00 00 00 48 89 c3 48 b8 00 00 00 00 00
> 3c 02 00 0f 85 02 01 00 00 f6 83 88 00 00 00 01 0f 84 a8 00 00
RSP: 0018:ffff88833cf87b08 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000011 RSI: 0000000000000004 RDI: 0000000000000088
RBP: 0000000000000002 R08: 0000000000000001 R09: ffffed102877b827
R10: ffff888143bdc13b R11: ffff888125b1cbc0 R12: ffff888143bdc000
R13: 0000000000007000 R14: ffff888125b1cba8 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88881e500000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3ed85223d5 CR3: 00000001519b4005 CR4: 00000000001706e0
Call Trace:
<TASK>
? die_addr+0x3c/0xa0
? exc_general_protection+0x148/0x220
? asm_exc_general_protection+0x22/0x30
? btrfs_zone_finish_endio.part.0+0x34/0x160 [btrfs]
? btrfs_zone_finish_endio.part.0+0x19/0x160 [btrfs]
btrfs_finish_one_ordered+0x7b8/0x1de0 [btrfs]
? rcu_is_watching+0x11/0xb0
? lock_release+0x47a/0x620
? btrfs_finish_ordered_zoned+0x59b/0x800 [btrfs]
? __pfx_btrfs_finish_one_ordered+0x10/0x10 [btrfs]
? btrfs_finish_ordered_zoned+0x358/0x800 [btrfs]
? __smp_call_single_queue+0x124/0x350
? rcu_is_watching+0x11/0xb0
btrfs_work_helper+0x19f/0xc60 [btrfs]
? __pfx_try_to_wake_up+0x10/0x10
? _raw_spin_unlock_irq+0x24/0x50
? rcu_is_watching+0x11/0xb0
process_one_work+0x8c1/0x1430
? __pfx_lock_acquire+0x10/0x10
? __pfx_process_one_work+0x10/0x10
? __pfx_do_raw_spin_lock+0x10/0x10
? _raw_spin_lock_irq+0x52/0x60
worker_thread+0x100/0x12c0
? __kthread_parkme+0xc1/0x1f0
? __pfx_worker_thread+0x10/0x10
kthread+0x2ea/0x3c0
? __pfx_kthread+0x10/0x10
ret_from_fork+0x30/0x70
? __pfx_kthread+0x10/0x10
ret_from_fork_asm+0x1b/0x30
</TASK>
On the zoned mode, writing to pre-allocated region means data relocation
write. Such write always uses WRITE command so there is no need of splitting
and rewriting logical address. Thus, we can just skip the function for the
case.
Fixes: cbfce4c7fbde ("btrfs: optimize the logical to physical mapping for zoned writes")
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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It's not necessary to use low-level locking helpers here. Use the
higher-level locking helpers and log if the superblock is dying. Since
the caller is assumed to already hold an active reference it isn't
possible to observe a dying superblock.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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It is particularly important for the userns mount case (when a sensible
nr_inodes maximum may not be enforced) that tmpfs user xattrs be subject
to memory cgroup limiting. Leave temporary buffer allocations as is,
but change the persistent simple xattr allocations from GFP_KERNEL to
GFP_KERNEL_ACCOUNT. This limits kernfs's cgroupfs too, but that's good.
(I had intended to send this change earlier, but had been confused by
shmem_alloc_inode() using GFP_KERNEL, and thought a discussion would be
needed to change that too: no, I was forgetting the SLAB_ACCOUNT on that
kmem_cache, which implicitly adds __GFP_ACCOUNT to all its allocations.)
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <f6953e5a-4183-8314-38f2-40be60998615@google.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Eric has pointed out that we still have 3 users of do_each_thread().
Change them to use for_each_process_thread() and kill this helper.
There is a subtle change, after do_each_thread/while_each_thread g == t ==
&init_task, while after for_each_process_thread() they both point to
nowhere, but this doesn't matter.
> Why is for_each_process_thread() better than do_each_thread()?
Say, for_each_process_thread() is rcu safe, do_each_thread() is not.
And certainly
for_each_process_thread(p, t) {
do_something(p, t);
}
looks better than
do_each_thread(p, t) {
do_something(p, t);
} while_each_thread(p, t);
And again, there are only 3 users of this awkward helper left. It should
have been killed years ago and in fact I thought it had already been
killed. It uses while_each_thread() which needs some changes.
Link: https://lkml.kernel.org/r/20230817163708.GA8248@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: "Christian Brauner (Microsoft)" <brauner@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jiri Slaby <jirislaby@kernel.org> # tty/serial
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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A syzbot stress test using a corrupted disk image reported that
mark_buffer_dirty() called from __nilfs_mark_inode_dirty() or
nilfs_palloc_commit_alloc_entry() may output a kernel warning, and can
panic if the kernel is booted with panic_on_warn.
This is because nilfs2 keeps buffer pointers in local structures for some
metadata and reuses them, but such buffers may be forcibly discarded by
nilfs_clear_dirty_page() in some critical situations.
This issue is reported to appear after commit 28a65b49eb53 ("nilfs2: do
not write dirty data after degenerating to read-only"), but the issue has
potentially existed before.
Fix this issue by checking the uptodate flag when attempting to reuse an
internally held buffer, and reloading the metadata instead of reusing the
buffer if the flag was lost.
Link: https://lkml.kernel.org/r/20230818131804.7758-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+cdfcae656bac88ba0e2d@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/0000000000003da75f05fdeffd12@google.com
Fixes: 8c26c4e2694a ("nilfs2: fix issue with flush kernel thread after remount in RO mode because of driver's internal error or metadata corruption")
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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xchg originated in 6e399cd144d8 ("prctl: avoid using mmap_sem for exe_file
serialization"). While the commit message does not explain *why* the
change, I found the original submission [1] which ultimately claims it
cleans things up by removing dependency of exe_file on the semaphore.
However, fe69d560b5bd ("kernel/fork: always deny write access to current
MM exe_file") added a semaphore up/down cycle to synchronize the state of
exe_file against fork, defeating the point of the original change.
This is on top of semaphore trips already present both in the replacing
function and prctl (the only consumer).
Normally replacing exe_file does not happen for busy processes, thus
write-locking is not an impediment to performance in the intended use
case. If someone keeps invoking the routine for a busy processes they are
trying to play dirty and that's another reason to avoid any trickery.
As such I think the atomic here only adds complexity for no benefit.
Just write-lock around the replacement.
I also note that replacement races against the mapping check loop as
nothing synchronizes actual assignment with with said checks but I am not
addressing it in this patch. (Is the loop of any use to begin with?)
Link: https://lore.kernel.org/linux-mm/1424979417.10344.14.camel@stgolabs.net/ [1]
Link: https://lkml.kernel.org/r/20230814172140.1777161-1-mjguzik@gmail.com
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: "Christian Brauner (Microsoft)" <brauner@kernel.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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union adfs_dirtail::new stands in the way if Linux++ project:
"new" can't be used as member's name because it is a keyword in C++.
Link: https://lkml.kernel.org/r/43b0a4c8-a7cf-4ab1-98f7-0f65c096f9e8@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Extract from current /proc/self/smaps output:
Swap: 0 kB
SwapPss: 0 kB
Locked: 0 kB
THPeligible: 0
ProtectionKey: 0
That's not the alignment shown in Documentation/filesystems/proc.rst: it's
an ugly artifact from missing out the %8 other fields are using; but
there's even one selftest which expects it to look that way. Hoping no
other smaps parsers depend on THPeligible to look so ugly, fix these.
Link: https://lkml.kernel.org/r/cfb81f7a-f448-5bc2-b0e1-8136fcd1dd8c@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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It is better to not expose too many internal variables of memtest,
add a helper memtest_report_meminfo() to show memtest results.
Link: https://lkml.kernel.org/r/20230808033359.174986-1-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tomas Mudrunka <tomas.mudrunka@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Implicit vma locking inside vm_flags_reset() and vm_flags_reset_once() is
not obvious and makes it hard to understand where vma locking is happening.
Also in some cases (like in dup_userfaultfd()) vma should be locked earlier
than vma_flags modification. To make locking more visible, change these
functions to assert that the vma write lock is taken and explicitly lock
the vma beforehand. Fix userfaultfd functions which should lock the vma
earlier.
Link: https://lkml.kernel.org/r/20230804152724.3090321-5-surenb@google.com
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: convert to vma_is_initial_heap/stack()", v3.
Add vma_is_initial_stack() and vma_is_initial_heap() helpers and use them
to simplify code.
This patch (of 4):
Factor out VMA stack and heap checks and name them vma_is_initial_stack()
and vma_is_initial_heap() for general use.
Link: https://lkml.kernel.org/r/20230728050043.59880-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20230728050043.59880-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@gmail.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Felix Kuehling <felix.kuehling@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The only user of frontswap is zswap, and has been for a long time. Have
swap call into zswap directly and remove the indirection.
[hannes@cmpxchg.org: remove obsolete comment, per Yosry]
Link: https://lkml.kernel.org/r/20230719142832.GA932528@cmpxchg.org
[fengwei.yin@intel.com: don't warn if none swapcache folio is passed to zswap_load]
Link: https://lkml.kernel.org/r/20230810095652.3905184-1-fengwei.yin@intel.com
Link: https://lkml.kernel.org/r/20230717160227.GA867137@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Nhat Pham <nphamcs@gmail.com>
Acked-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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A syzbot stress test reported that create_empty_buffers() called from
nilfs_lookup_dirty_data_buffers() can cause a general protection fault.
Analysis using its reproducer revealed that the back reference "mapping"
from a page/folio has been changed to NULL after dirty page/folio gang
lookup in nilfs_lookup_dirty_data_buffers().
Fix this issue by excluding pages/folios from being collected if, after
acquiring a lock on each page/folio, its back reference "mapping" differs
from the pointer to the address space struct that held the page/folio.
Link: https://lkml.kernel.org/r/20230805132038.6435-1-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Reported-by: syzbot+0ad741797f4565e7e2d2@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/0000000000002930a705fc32b231@google.com
Tested-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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walk_page_range() and friends often operate under write-locked mmap_lock.
With introduction of vma locks, the vmas have to be locked as well during
such walks to prevent concurrent page faults in these areas. Add an
additional member to mm_walk_ops to indicate locking requirements for the
walk.
The change ensures that page walks which prevent concurrent page faults
by write-locking mmap_lock, operate correctly after introduction of
per-vma locks. With per-vma locks page faults can be handled under vma
lock without taking mmap_lock at all, so write locking mmap_lock would
not stop them. The change ensures vmas are properly locked during such
walks.
A sample issue this solves is do_mbind() performing queue_pages_range()
to queue pages for migration. Without this change a concurrent page
can be faulted into the area and be left out of migration.
Link: https://lkml.kernel.org/r/20230804152724.3090321-2-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Suggested-by: Jann Horn <jannh@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michel Lespinasse <michel@lespinasse.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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We shouldn't be using a GUP-internal helper if it can be avoided.
Similar to smaps_pte_entry() that uses vm_normal_page(), let's use
vm_normal_page_pmd() that similarly refuses to return the huge zeropage.
In contrast to follow_trans_huge_pmd(), vm_normal_page_pmd():
(1) Will always return the head page, not a tail page of a THP.
If we'd ever call smaps_account with a tail page while setting "compound
= true", we could be in trouble, because smaps_account() would look at
the memmap of unrelated pages.
If we're unlucky, that memmap does not exist at all. Before we removed
PG_doublemap, we could have triggered something similar as in
commit 24d7275ce279 ("fs/proc: task_mmu.c: don't read mapcount for
migration entry").
This can theoretically happen ever since commit ff9f47f6f00c ("mm: proc:
smaps_rollup: do not stall write attempts on mmap_lock"):
(a) We're in show_smaps_rollup() and processed a VMA
(b) We release the mmap lock in show_smaps_rollup() because it is
contended
(c) We merged that VMA with another VMA
(d) We collapsed a THP in that merged VMA at that position
If the end address of the original VMA falls into the middle of a THP
area, we would call smap_gather_stats() with a start address that falls
into a PMD-mapped THP. It's probably very rare to trigger when not
really forced.
(2) Will succeed on a is_pci_p2pdma_page(), like vm_normal_page()
Treat such PMDs here just like smaps_pte_entry() would treat such PTEs.
If such pages would be anonymous, we most certainly would want to
account them.
(3) Will skip over pmd_devmap(), like vm_normal_page() for pte_devmap()
As noted in vm_normal_page(), that is only for handling legacy ZONE_DEVICE
pages. So just like smaps_pte_entry(), we'll now also ignore such PMD
entries.
Especially, follow_pmd_mask() never ends up calling
follow_trans_huge_pmd() on pmd_devmap(). Instead it calls
follow_devmap_pmd() -- which will fail if neither FOLL_GET nor FOLL_PIN
is set.
So skipping pmd_devmap() pages seems to be the right thing to do.
(4) Will properly handle VM_MIXEDMAP/VM_PFNMAP, like vm_normal_page()
We won't be returning a memmap that should be ignored by core-mm, or
worse, a memmap that does not even exist. Note that while
walk_page_range() will skip VM_PFNMAP mappings, walk_page_vma() won't.
Most probably this case doesn't currently really happen on the PMD level,
otherwise we'd already be able to trigger kernel crashes when reading
smaps / smaps_rollup.
So most probably only (1) is relevant in practice as of now, but could only
cause trouble in extreme corner cases.
Let's move follow_trans_huge_pmd() to mm/internal.h to discourage future
reuse in wrong context.
Link: https://lkml.kernel.org/r/20230803143208.383663-3-david@redhat.com
Fixes: ff9f47f6f00c ("mm: proc: smaps_rollup: do not stall write attempts on mmap_lock")
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: liubo <liubo254@huawei.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Recent rework moved block device closing out of sb->put_super() and into
sb->kill_sb() to avoid deadlocks as s_umount is held in put_super() and
blkdev_put() can end up taking s_umount again.
That means we need to move the removal of the superblock from @fs_supers
out of generic_shutdown_super() and into deactivate_locked_super() to
ensure that concurrent mounters don't fail to open block devices that
are still in use because blkdev_put() in sb->kill_sb() hasn't been
called yet.
We can now do this as we can make iterators through @fs_super and
@super_blocks wait without holding s_umount. Concurrent mounts will wait
until a dying superblock is fully dead so until sb->kill_sb() has been
called and SB_DEAD been set. Concurrent iterators can already discard
any SB_DYING superblock.
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230818-vfs-super-fixes-v3-v3-4-9f0b1876e46b@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Recent patches experiment with making it possible to allocate a new
superblock before opening the relevant block device. Naturally this has
intricate side-effects that we get to learn about while developing this.
Superblock allocators such as sget{_fc}() return with s_umount of the
new superblock held and lock ordering currently requires that block
level locks such as bdev_lock and open_mutex rank above s_umount.
Before aca740cecbe5 ("fs: open block device after superblock creation")
ordering was guaranteed to be correct as block devices were opened prior
to superblock allocation and thus s_umount wasn't held. But now s_umount
must be dropped before opening block devices to avoid locking
violations.
This has consequences. The main one being that iterators over
@super_blocks and @fs_supers that grab a temporary reference to the
superblock can now also grab s_umount before the caller has managed to
open block devices and called fill_super(). So whereas before such
iterators or concurrent mounts would have simply slept on s_umount until
SB_BORN was set or the superblock was discard due to initalization
failure they can now needlessly spin through sget{_fc}().
If the caller is sleeping on bdev_lock or open_mutex one caller waiting
on SB_BORN will always spin somewhere and potentially this can go on for
quite a while.
It should be possible to drop s_umount while allowing iterators to wait
on a nascent superblock to either be born or discarded. This patch
implements a wait_var_event() mechanism allowing iterators to sleep
until they are woken when the superblock is born or discarded.
This also allows us to avoid relooping through @fs_supers and
@super_blocks if a superblock isn't yet born or dying.
Link: aca740cecbe5 ("fs: open block device after superblock creation")
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230818-vfs-super-fixes-v3-v3-3-9f0b1876e46b@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Use helpers instead of the open coded dance to silence lockdep warnings.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Message-Id: <20230817141337.1025891-8-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Use helpers instead of the open coded dance to silence lockdep warnings.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Message-Id: <20230817141337.1025891-7-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Use helpers instead of the open coded dance to silence lockdep warnings.
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Message-Id: <20230817141337.1025891-6-amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Convert buf->page to a folio once instead of five times. There's only
one uptodate bit per folio, not per page, so we lose nothing here.
Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Message-Id: <20230821141541.2535953-1-willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
Remove a number of implicit calls to compound_head() and various calls
to compatibility functions. This is not sufficient to enable support
for large folios; generic_perform_write() must be converted first.
Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Message-Id: <20230821141322.2535459-1-willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
|
|
This reproduces the bug fixed by "btrfs: fix incorrect splitting in
btrfs_drop_extent_map_range", we were improperly calculating the range
for the split extent. Add a test that exercises this scenario and
validates that we get the correct resulting extent_maps in our tree.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
This helper is different from the normal add_extent_mapping in that it
will stuff an em into a gap that exists between overlapping em's in the
tree. It appeared there was a bug so I wrote a self test to validate it
did the correct thing when it worked with two side by side ems.
Thankfully it is correct, but more testing is better.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
While investigating weird problems with the extent_map I wrote a self
test testing the various edge cases of btrfs_drop_extent_map_range.
This can split in different ways and behaves different in each case, so
test the various edge cases to make sure everything is functioning
properly.
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
scrub_stripe_read_repair_worker()
Currently the scrub_stripe_read_repair_worker() only does reads to
rebuild the corrupted sectors, it doesn't do any writeback.
The design is mostly to put writeback into a more ordered manner, to
co-operate with dev-replace with zoned mode, which requires every write
to be submitted in their bytenr order.
However the writeback for repaired sectors into the original mirror
doesn't need such strong sync requirement, as it can only happen for
non-zoned devices.
This patch would move the writeback for repaired sectors into
scrub_stripe_read_repair_worker(), which removes two calls sites for
repaired sectors writeback. (one from flush_scrub_stripes(), one from
scrub_raid56_parity_stripe())
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The workqueue fs_info->scrub_worker would go ordered workqueue if it's a
device replace operation.
However the scrub is relying on multiple workers to do data csum
verification, and we always submit several read requests in a row.
Thus there is no need to use ordered workqueue just for dev-replace.
We have extra synchronization (the main thread will always
submit-and-wait for dev-replace writes) to handle it for zoned devices.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
[REGRESSION]
There are several regression reports about the scrub performance with
v6.4 kernel.
On a PCIe 3.0 device, the old v6.3 kernel can go 3GB/s scrub speed, but
v6.4 can only go 1GB/s, an obvious 66% performance drop.
[CAUSE]
Iostat shows a very different behavior between v6.3 and v6.4 kernel:
Device r/s rkB/s rrqm/s %rrqm r_await rareq-sz aqu-sz %util
nvme0n1p3 9731.00 3425544.00 17237.00 63.92 2.18 352.02 21.18 100.00
nvme0n1p3 15578.00 993616.00 5.00 0.03 0.09 63.78 1.32 100.00
The upper one is v6.3 while the lower one is v6.4.
There are several obvious differences:
- Very few read merges
This turns out to be a behavior change that we no longer do bio
plug/unplug.
- Very low aqu-sz
This is due to the submit-and-wait behavior of flush_scrub_stripes(),
and extra extent/csum tree search.
Both behaviors are not that obvious on SATA SSDs, as SATA SSDs have NCQ
to merge the reads, while SATA SSDs can not handle high queue depth well
either.
[FIX]
For now this patch focuses on the read speed fix. Dev-replace replace
speed needs more work.
For the read part, we go two directions to fix the problems:
- Re-introduce blk plug/unplug to merge read requests
This is pretty simple, and the behavior is pretty easy to observe.
This would enlarge the average read request size to 512K.
- Introduce multi-group reads and no longer wait for each group
Instead of the old behavior, which submits 8 stripes and waits for
them, here we would enlarge the total number of stripes to 16 * 8.
Which is 8M per device, the same limit as the old scrub in-flight
bios size limit.
Now every time we fill a group (8 stripes), we submit them and
continue to next stripes.
Only when the full 16 * 8 stripes are all filled, we submit the
remaining ones (the last group), and wait for all groups to finish.
Then submit the repair writes and dev-replace writes.
This should enlarge the queue depth.
This would greatly improve the merge rate (thus read block size) and
queue depth:
Before (with regression, and cached extent/csum path):
Device r/s rkB/s rrqm/s %rrqm r_await rareq-sz aqu-sz %util
nvme0n1p3 20666.00 1318240.00 10.00 0.05 0.08 63.79 1.63 100.00
After (with all patches applied):
nvme0n1p3 5165.00 2278304.00 30557.00 85.54 0.55 441.10 2.81 100.00
i.e. 1287 to 2224 MB/s.
CC: stable@vger.kernel.org # 6.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
One of the bottleneck of the new scrub code is the extra csum tree
search.
The old code would only do the csum tree search for each scrub bio,
which can be as large as 512KiB, thus they can afford to allocate a new
path each time.
But the new scrub code is doing csum tree search for each stripe, which
is only 64KiB, this means we'd better re-use the same csum path during
each search.
This patch would introduce a per-sctx path for csum tree search, as we
don't need to re-allocate the path every time we need to do a csum tree
search.
With this change we can further improve the queue depth and improve the
scrub read performance:
Before (with regression and cached extent tree path):
Device r/s rkB/s rrqm/s %rrqm r_await rareq-sz aqu-sz %util
nvme0n1p3 15875.00 1013328.00 12.00 0.08 0.08 63.83 1.35 100.00
After (with both cached extent/csum tree path):
nvme0n1p3 17759.00 1133280.00 10.00 0.06 0.08 63.81 1.50 100.00
Fixes: e02ee89baa66 ("btrfs: scrub: switch scrub_simple_mirror() to scrub_stripe infrastructure")
CC: stable@vger.kernel.org # 6.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Since commit e02ee89baa66 ("btrfs: scrub: switch scrub_simple_mirror()
to scrub_stripe infrastructure"), scrub no longer re-use the same path
for extent tree search.
This can lead to unnecessary extent tree search, especially for the new
stripe based scrub, as we have way more stripes to prepare.
This patch would re-introduce a shared path for extent tree search, and
properly release it when the block group is scrubbed.
This change alone can improve scrub performance slightly by reducing the
time spend preparing the stripe thus improving the queue depth.
Before (with regression):
Device r/s rkB/s rrqm/s %rrqm r_await rareq-sz aqu-sz %util
nvme0n1p3 15578.00 993616.00 5.00 0.03 0.09 63.78 1.32 100.00
After (with this patch):
nvme0n1p3 15875.00 1013328.00 12.00 0.08 0.08 63.83 1.35 100.00
Fixes: e02ee89baa66 ("btrfs: scrub: switch scrub_simple_mirror() to scrub_stripe infrastructure")
CC: stable@vger.kernel.org # 6.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
btrfs supports creating nested subvolumes however snapshots are not
recursive. When a snapshot is taken of a volume which contains a
subvolume the subvolume is replaced with a stub subvolume which has the
same name and uses inode number 2[1]. The stub subvolume kept the
directory name but did not set the time or permissions of the stub
subvolume. This resulted in all time information being the current time
and ownership defaulting to root. When subvolumes and snapshots are
created using unshare this results in a snapshot directory the user
created but has no permissions for.
Test case:
[vmuser@archvm ~]# sudo -i
[root@archvm ~]# mkdir -p /mnt/btrfs/test
[root@archvm ~]# chown vmuser:users /mnt/btrfs/test/
[root@archvm ~]# exit
logout
[vmuser@archvm ~]$ cd /mnt/btrfs/test
[vmuser@archvm test]$ unshare --user --keep-caps --map-auto --map-root-user
[root@archvm test]# btrfs subvolume create subvolume
Create subvolume './subvolume'
[root@archvm test]# btrfs subvolume create subvolume/subsubvolume
Create subvolume 'subvolume/subsubvolume'
[root@archvm test]# btrfs subvolume snapshot subvolume snapshot
Create a snapshot of 'subvolume' in './snapshot'
[root@archvm test]# exit
logout
[vmuser@archvm test]$ tree -ug
[vmuser users ] .
├── [vmuser users ] snapshot
│ └── [vmuser users ] subsubvolume <-- Without patch perm is root:root
└── [vmuser users ] subvolume
└── [vmuser users ] subsubvolume
5 directories, 0 files
[1] https://btrfs.readthedocs.io/en/latest/btrfs-subvolume.html#nested-subvolumes
Signed-off-by: Lee Trager <lee@trager.us>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
At btrfs_readdir_delayed_dir_index(), called when reading a directory, we
have this check for an empty list to return immediately, but it's not
needed since list_for_each_entry_safe(), called immediately after, is
prepared to deal with an empty list, it simply does nothing. So remove
the empty list check.
Besides shorter source code, it also slightly reduces the binary text
size:
Before this change:
$ size fs/btrfs/btrfs.ko
text data bss dec hex filename
1609408 167269 16864 1793541 1b5e05 fs/btrfs/btrfs.ko
After this change:
$ size fs/btrfs/btrfs.ko
text data bss dec hex filename
1609392 167269 16864 1793525 1b5df5 fs/btrfs/btrfs.ko
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
fs_devices::metadata_uuid value is already updated based on the
super_block::METADATA_UUID flag for either fsid or metadata_uuid as
appropriate. So, fs_devices::metadata_uuid can be used directly.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The function btrfs_validate_super() should verify the metadata_uuid in
the provided superblock argument. Because, all its callers expect it to
do that.
Such as in the following stacks:
write_all_supers()
sb = fs_info->super_for_commit;
btrfs_validate_write_super(.., sb)
btrfs_validate_super(.., sb, ..)
scrub_one_super()
btrfs_validate_super(.., sb, ..)
And
check_dev_super()
btrfs_validate_super(.., sb, ..)
However, it currently verifies the fs_info::super_copy::metadata_uuid
instead. Fix this using the correct metadata_uuid in the superblock
argument.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The function btrfs_validate_super() should verify the fsid in the provided
superblock argument. Because, all its callers expect it to do that.
Such as in the following stack:
write_all_supers()
sb = fs_info->super_for_commit;
btrfs_validate_write_super(.., sb)
btrfs_validate_super(.., sb, ..)
scrub_one_super()
btrfs_validate_super(.., sb, ..)
And
check_dev_super()
btrfs_validate_super(.., sb, ..)
However, it currently verifies the fs_info::super_copy::fsid instead,
which is not correct. Fix this using the correct fsid in the superblock
argument.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
There is a helper which provides either metadata_uuid or fsid as per
METADATA_UUID flag. So use it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
In some cases, we need to read the FSID from the superblock when the
metadata_uuid is not set, and otherwise, read the metadata_uuid. So,
add a helper.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
The v0 extent item has been deprecated for a long time, and we don't have
any report from the community either.
So it's time to remove the v0 extent specific error handling, and just
treat them as regular extent tree corruption.
This patch would remove the btrfs_print_v0_err() helper, and enhance the
involved error handling to treat them just as any extent tree
corruption. No reports regarding v0 extents have been seen since the
graceful handling was added in 2018.
This involves:
- btrfs_backref_add_tree_node()
This change is a little tricky, the new code is changed to only handle
BTRFS_TREE_BLOCK_REF_KEY and BTRFS_SHARED_BLOCK_REF_KEY.
But this is safe, as we have rejected any unknown inline refs through
btrfs_get_extent_inline_ref_type().
For keyed backrefs, we're safe to skip anything we don't know (that's
if it can pass tree-checker in the first place).
- btrfs_lookup_extent_info()
- lookup_inline_extent_backref()
- run_delayed_extent_op()
- __btrfs_free_extent()
- add_tree_block()
Regular error handling of unexpected extent tree item, and abort
transaction (if we have a trans handle).
- remove_extent_data_ref()
It's pretty much the same as the regular rejection of unknown backref
key.
But for this particular case, we can also remove a BUG_ON().
- extent_data_ref_count()
We can remove the BTRFS_EXTENT_REF_V0_KEY BUG_ON(), as it would be
rejected by the only caller.
- btrfs_print_leaf()
Remove the handling for BTRFS_EXTENT_REF_V0_KEY.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
[BUG]
Syzbot reported several warning triggered inside
lookup_inline_extent_backref().
[CAUSE]
As usual, the reproducer doesn't reliably trigger locally here, but at
least we know the WARN_ON() is triggered when an inline backref can not
be found, and it can only be triggered when @insert is true. (I.e.
inserting a new inline backref, which means the backref should already
exist)
[ENHANCEMENT]
After the WARN_ON(), dump all the parameters and the extent tree
leaf to help debug.
Link: https://syzkaller.appspot.com/bug?extid=d6f9ff86c1d804ba2bc6
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Having the assert in the actual helper documents the pre-conditions
much better than having it in the caller, so move it.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Share the calls to extent_clear_unlock_delalloc for btrfs_path allocation
failure handling and the normal exit path.
This relies on btrfs_free_path ignoring a NULL pointer, and the
initialization of cur_offset to start at the beginning of the function.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
Use the block group pointer used to track the outstanding NOCOW writes as
a boolean to remove the duplicate nocow variable, and keep it contained
in the main loop to simplify the logic.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
When run_delalloc_nocow has cow_start set to a value other than (u64)-1,
it has delayed COW writeback pending behind cur_offset. When an error
occurs in such a window, the range going back to cow_start and not just
cur_offset needs to be unlocked, but only two error cases handle this
correctly Move the code to handle unlock the COW range to the common
error handling label and document the logic.
To make things even more complicated, cow_file_range as called by
fallback_to_cow will unlock the range it is operating on when it fails as
well, so we need to reset cow_start right after caling fallback_to_cow
instead of only when it succeeded.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
When multiple writes happen at once, we may need to sacrifice a currently
active block group to be zone finished for a new allocation. We choose a
block group with the least free space left, and zone finish it.
To do the finishing, we need to send IOs for already allocated region
and wait for them and on-going IOs. Otherwise, these IOs fail because the
zone is already finished at the time the IO reach a device.
However, if a block group dedicated to the data relocation is zone
finished, there is a chance that finishing it before an ongoing write IO
reaches the device. That is because there is timing gap between an
allocation is done (block_group->reservations == 0, as pre-allocation is
done) and an ordered extent is created when the relocation IO starts.
Thus, if we finish the zone between them, we can fail the IOs.
We cannot simply use "fs_info->data_reloc_bg == block_group->start" to
avoid the zone finishing. Because, the data_reloc_bg may already switch to
a new block group, while there are still ongoing write IOs to the old
data_reloc_bg.
So, this patch reworks the BLOCK_GROUP_FLAG_ZONED_DATA_RELOC bit to
indicate there is a data relocation allocation and/or ongoing write to the
block group. The bit is set on allocation and cleared in end_io function of
the last IO for the currently allocated region.
To change the timing of the bit setting also solves the issue that the bit
being left even after there is no IO going on. With the current code, if
the data_reloc_bg switches after the last IO to the current data_reloc_bg,
the bit is set at this timing and there is no one clearing that bit. As a
result, that block group is kept unallocatable for anything.
Fixes: 343d8a30851c ("btrfs: zoned: prevent allocation from previous data relocation BG")
Fixes: 74e91b12b115 ("btrfs: zoned: zone finish unused block group")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
One of the CI runs triggered the following panic
assertion failed: PagePrivate(page) && page->private, in fs/btrfs/subpage.c:229
------------[ cut here ]------------
kernel BUG at fs/btrfs/subpage.c:229!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
CPU: 0 PID: 923660 Comm: btrfs Not tainted 6.5.0-rc3+ #1
pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
pc : btrfs_subpage_assert+0xbc/0xf0
lr : btrfs_subpage_assert+0xbc/0xf0
sp : ffff800093213720
x29: ffff800093213720 x28: ffff8000932138b4 x27: 000000000c280000
x26: 00000001b5d00000 x25: 000000000c281000 x24: 000000000c281fff
x23: 0000000000001000 x22: 0000000000000000 x21: ffffff42b95bf880
x20: ffff42b9528e0000 x19: 0000000000001000 x18: ffffffffffffffff
x17: 667274622f736620 x16: 6e69202c65746176 x15: 0000000000000028
x14: 0000000000000003 x13: 00000000002672d7 x12: 0000000000000000
x11: ffffcd3f0ccd9204 x10: ffffcd3f0554ae50 x9 : ffffcd3f0379528c
x8 : ffff800093213428 x7 : 0000000000000000 x6 : ffffcd3f091771e8
x5 : ffff42b97f333948 x4 : 0000000000000000 x3 : 0000000000000000
x2 : 0000000000000000 x1 : ffff42b9556cde80 x0 : 000000000000004f
Call trace:
btrfs_subpage_assert+0xbc/0xf0
btrfs_subpage_set_dirty+0x38/0xa0
btrfs_page_set_dirty+0x58/0x88
relocate_one_page+0x204/0x5f0
relocate_file_extent_cluster+0x11c/0x180
relocate_data_extent+0xd0/0xf8
relocate_block_group+0x3d0/0x4e8
btrfs_relocate_block_group+0x2d8/0x490
btrfs_relocate_chunk+0x54/0x1a8
btrfs_balance+0x7f4/0x1150
btrfs_ioctl+0x10f0/0x20b8
__arm64_sys_ioctl+0x120/0x11d8
invoke_syscall.constprop.0+0x80/0xd8
do_el0_svc+0x6c/0x158
el0_svc+0x50/0x1b0
el0t_64_sync_handler+0x120/0x130
el0t_64_sync+0x194/0x198
Code: 91098021 b0007fa0 91346000 97e9c6d2 (d4210000)
This is the same problem outlined in 17b17fcd6d44 ("btrfs:
set_page_extent_mapped after read_folio in btrfs_cont_expand") , and the
fix is the same. I originally looked for the same pattern elsewhere in
our code, but mistakenly skipped over this code because I saw the page
cache readahead before we set_page_extent_mapped, not realizing that
this was only in the !page case, that we can still end up with a
!uptodate page and then do the btrfs_read_folio further down.
The fix here is the same as the above mentioned patch, move the
set_page_extent_mapped call to after the btrfs_read_folio() block to
make sure that we have the subpage blocksize stuff setup properly before
using the page.
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
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My initial fix for the generic/475 hangs was related to metadata, but
our CI testing uncovered another case where we hang for similar reasons.
We again have a task with a plug that is holding an outstanding request
that is keeping the dm device from finishing it's suspend, and that task
is stuck in the allocator.
This time it is stuck trying to allocate data, but we do not have a
block group that matches the size class. The larger loop in the
allocator looks like this (simplified of course)
find_free_extent
for_each_block_group {
ffe_ctl->cached == btrfs_block_group_cache_done(bg)
if (!ffe_ctl->cached)
ffe_ctl->have_caching_bg = true;
do_allocation()
btrfs_wait_block_group_cache_progress();
}
if (loop == LOOP_CACHING_WAIT && ffe_ctl->have_caching_bg)
go search again;
In my earlier fix we were trying to allocate from the block group, but
we weren't waiting for the progress because we were only waiting for the
free space to be >= the amount of free space we wanted. My fix made it
so we waited for forward progress to be made as well, so we would be
sure to wait.
This time however we did not have a block group that matched our size
class, so what was happening was this
find_free_extent
for_each_block_group {
ffe_ctl->cached == btrfs_block_group_cache_done(bg)
if (!ffe_ctl->cached)
ffe_ctl->have_caching_bg = true;
if (size_class_doesn't_match())
goto loop;
do_allocation()
btrfs_wait_block_group_cache_progress();
loop:
release_block_group(block_group);
}
if (loop == LOOP_CACHING_WAIT && ffe_ctl->have_caching_bg)
go search again;
The size_class_doesn't_match() part was true, so we'd just skip this
block group and never wait for caching, and then because we found a
caching block group we'd just go back and do the loop again. We never
sleep and thus never flush the plug and we have the same deadlock.
Fix the logic for waiting on the block group caching to instead do it
unconditionally when we goto loop. This takes the logic out of the
allocation step, so now the loop looks more like this
find_free_extent
for_each_block_group {
ffe_ctl->cached == btrfs_block_group_cache_done(bg)
if (!ffe_ctl->cached)
ffe_ctl->have_caching_bg = true;
if (size_class_doesn't_match())
goto loop;
do_allocation()
btrfs_wait_block_group_cache_progress();
loop:
if (loop > LOOP_CACHING_NOWAIT && !ffe_ctl->retry_uncached &&
!ffe_ctl->cached) {
ffe_ctl->retry_uncached = true;
btrfs_wait_block_group_cache_progress();
}
release_block_group(block_group);
}
if (loop == LOOP_CACHING_WAIT && ffe_ctl->have_caching_bg)
go search again;
This simplifies the logic a lot, and makes sure that if we're hitting
uncached block groups we're always waiting on them at some point.
I ran this through 100 iterations of generic/475, as this particular
case was harder to hit than the previous one.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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