a) Dirty cache needs to be written back not just in the writeback_cache
case, since the dirty pages may come from memory maps.
b) The fuse_writeback_range() helper takes an inclusive interval, so the
end position needs to be pos+len-1 instead of pos+len.
Fixes: 88bc7d5097 ("fuse: add support for copy_file_range()")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
A GETATTR request can race with FUSE_NOTIFY_INVAL_INODE, resulting in the
attribute cache being updated with stale information after the
invalidation.
Fix this by bumping the attribute version in fuse_reverse_inval_inode().
Reported-by: Krzysztof Rusek <rusek@9livesdata.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
page_count() is unstable. Unless there has been an RCU grace period
between when the page was removed from the page cache and now, a
speculative reference may exist from the page cache.
Reported-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
When PageWaiters was added, updating this check was missed.
Reported-by: Nikolaus Rath <Nikolaus@rath.org>
Reported-by: Hugh Dickins <hughd@google.com>
Fixes: 6290602709 ("mm: add PageWaiters indicating tasks are waiting for a page bit")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Instead of custom page dumping, use the standard helper.
Reported-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
fuse_fill_super_common() allocates and installs one fuse_device. Hence
virtiofs allocates and install all fuse devices by itself except one.
This makes logic little twisted. There does not seem to be any real need
that why virtiofs can't allocate and install all fuse devices itself.
So opt out of fuse device allocation and installation while calling
fuse_fill_super_common().
Regular fuse still wants fuse_fill_super_common() to install fuse_device.
It needs to prevent against races where two mounters are trying to mount
fuse using same fd. In that case one will succeed while other will get
-EINVAL.
virtiofs does not have this issue because sget_fc() resolves the race
w.r.t multiple mounters and only one instance of virtio_fs_fill_super()
should be in progress for same filesystem.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fuse mounts without "allow_other" are off-limits to all non-owners. Yet it
makes sense to allow querying st_dev on the root, since this value is
provided by the kernel, not the userspace filesystem.
Allow statx(2) with a zero request mask to succeed on a fuse mounts for all
users.
Reported-by: Nikolaus Rath <Nikolaus@rath.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
We want cached data to synced with the userspace filesystem on close(), for
example to allow getting correct st_blocks value. Do this regardless of
whether the userspace filesystem implements a FLUSH method or not.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Under writeback mode, inode->i_blocks is not updated, making utils du
read st.blocks as 0.
For example, when using virtiofs (cache=always & nondax mode) with
writeback_cache enabled, writing a new file and check its disk usage
with du, du reports 0 usage.
# uname -r
5.6.0-rc6+
# mount -t virtiofs virtiofs /mnt/virtiofs
# rm -f /mnt/virtiofs/testfile
# create new file and do extend write
# xfs_io -fc "pwrite 0 4k" /mnt/virtiofs/testfile
wrote 4096/4096 bytes at offset 0
4 KiB, 1 ops; 0.0001 sec (28.103 MiB/sec and 7194.2446 ops/sec)
# du -k /mnt/virtiofs/testfile
0 <==== disk usage is 0
# stat -c %s,%b /mnt/virtiofs/testfile
4096,0 <==== i_size is correct, but st_blocks is 0
Fix it by invalidating attr in fuse_flush(), so we get up-to-date attr
from server on next getattr.
Signed-off-by: Eryu Guan <eguan@linux.alibaba.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
commit 9635453572 ("fuse: reduce allocation size for splice_write")
changed size of bufs array, so BUG_ON which checks the index of the array
shold also be fixed.
[SzM: turn BUG_ON into WARN_ON]
Fixes: 9635453572 ("fuse: reduce allocation size for splice_write")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
In virtiofs (unlike in regular fuse) processing of async replies is
serialized. This can result in a deadlock in rare corner cases when
there's a circular dependency between the completion of two or more async
replies.
Such a deadlock can be reproduced with xfstests:generic/503 if TEST_DIR ==
SCRATCH_MNT (which is a misconfiguration):
- Process A is waiting for page lock in worker thread context and blocked
(virtio_fs_requests_done_work()).
- Process B is holding page lock and waiting for pending writes to
finish (fuse_wait_on_page_writeback()).
- Write requests are waiting in virtqueue and can't complete because
worker thread is blocked on page lock (process A).
Fix this by creating a unique work_struct for each async reply that can
block (O_DIRECT read).
Fixes: a62a8ef9d9 ("virtio-fs: add virtiofs filesystem")
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
instead of clockid numbers. The usability nuisance of numbers was noticed
by Michael when polishing the man page.
-----BEGIN PGP SIGNATURE-----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=slEk
-----END PGP SIGNATURE-----
Merge tag 'timers-urgent-2020-04-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull time namespace fix from Thomas Gleixner:
"An update for the proc interface of time namespaces: Use symbolic
names instead of clockid numbers. The usability nuisance of numbers
was noticed by Michael when polishing the man page"
* tag 'timers-urgent-2020-04-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
proc, time/namespace: Show clock symbolic names in /proc/pid/timens_offsets
generic/388 in data=journal mode, removing some BUG_ON's, and cleaning
up some compiler warnings.
-----BEGIN PGP SIGNATURE-----
iQEzBAABCAAdFiEEK2m5VNv+CHkogTfJ8vlZVpUNgaMFAl6cj80ACgkQ8vlZVpUN
gaOx5Qf/XY7JUEp1nGgcdZyUd8uho3dKkG4TuUU5PvGsiDb4ozGsyU51q2LnOHWF
uzDJaE03z5uc1i8C9mQRLzjzaOC8B8kQZuKfkcQ/xI4CS3cG4qRdeNdHUz5QyfhK
5THDzr2z1tuWDuhlp+jCPjCz1fJowHxva/7ktf1OrMVEErYlZXT8CPLIRBCeuuCX
/07/8tJ5jJoqpI3kmy1jFotMEhIBE0vixf+sfcp2RWjdb0/1LH2JPWCytX+hhSFR
SadWDvTIvVy/rMahLHgc/VyPP47QwLWzBmLm9CdyxmDeUaM4Qwx8Zfog4+8g78wl
IvSuHRDdTYnOO35Qbzjl2wanhzCiQQ==
=qzEh
-----END PGP SIGNATURE-----
Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"Miscellaneous bug fixes and cleanups for ext4, including a fix for
generic/388 in data=journal mode, removing some BUG_ON's, and cleaning
up some compiler warnings"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: convert BUG_ON's to WARN_ON's in mballoc.c
ext4: increase wait time needed before reuse of deleted inode numbers
ext4: remove set but not used variable 'es' in ext4_jbd2.c
ext4: remove set but not used variable 'es'
ext4: do not zeroout extents beyond i_disksize
ext4: fix return-value types in several function comments
ext4: use non-movable memory for superblock readahead
ext4: use matching invalidatepage in ext4_writepage
-----BEGIN PGP SIGNATURE-----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=G+Rl
-----END PGP SIGNATURE-----
Merge tag '5.7-rc-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs fixes from Steve French:
"Three small smb3 fixes: two debug related (helping network tracing for
SMB2 mounts, and the other removing an unintended debug line on
signing failures), and one fixing a performance problem with 64K
pages"
* tag '5.7-rc-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
smb3: remove overly noisy debug line in signing errors
cifs: improve read performance for page size 64KB & cache=strict & vers=2.1+
cifs: dump the session id and keys also for SMB2 sessions
- Fix a partially uninitialized variable.
- Teach the background gc threads to apply for fsfreeze protection.
- Fix some scaling problems when multiple threads try to flush the
filesystem when we're about to hit ENOSPC.
-----BEGIN PGP SIGNATURE-----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=YkcH
-----END PGP SIGNATURE-----
Merge tag 'xfs-5.7-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs fixes from Darrick Wong:
"The three commits here fix some livelocks and other clashes with
fsfreeze, a potential corruption problem, and a minor race between
processes freeing and allocating space when the filesystem is near
ENOSPC.
Summary:
- Fix a partially uninitialized variable.
- Teach the background gc threads to apply for fsfreeze protection.
- Fix some scaling problems when multiple threads try to flush the
filesystem when we're about to hit ENOSPC"
* tag 'xfs-5.7-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: move inode flush to the sync workqueue
xfs: fix partially uninitialized structure in xfs_reflink_remap_extent
xfs: acquire superblock freeze protection on eofblocks scans
Pull proc fix from Eric Biederman:
"While running syzbot happened to spot one more oversight in my rework
of proc_flush_task.
The fields proc_self and proc_thread_self were not being reinitialized
when proc was unmounted, which could cause problems if the mount of
proc fails"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
proc: Handle umounts cleanly
-----BEGIN PGP SIGNATURE-----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=n9hr
-----END PGP SIGNATURE-----
Merge tag 'io_uring-5.7-2020-04-17' of git://git.kernel.dk/linux-block
Pull io_uring fixes from Jens Axboe:
- wrap up the init/setup cleanup (Pavel)
- fix some issues around deferral sequences (Pavel)
- fix splice punt check using the wrong struct file member
- apply poll re-arm logic for pollable retry too
- pollable retry should honor cancelation
- fix setup time error handling syzbot reported crash
- restore work state when poll is canceled
* tag 'io_uring-5.7-2020-04-17' of git://git.kernel.dk/linux-block:
io_uring: don't count rqs failed after current one
io_uring: kill already cached timeout.seq_offset
io_uring: fix cached_sq_head in io_timeout()
io_uring: only post events in io_poll_remove_all() if we completed some
io_uring: io_async_task_func() should check and honor cancelation
io_uring: check for need to re-wait in polled async handling
io_uring: correct O_NONBLOCK check for splice punt
io_uring: restore req->work when canceling poll request
io_uring: move all request init code in one place
io_uring: keep all sqe->flags in req->flags
io_uring: early submission req fail code
io_uring: track mm through current->mm
io_uring: remove obsolete @mm_fault
-----BEGIN PGP SIGNATURE-----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=s26U
-----END PGP SIGNATURE-----
Merge tag 'for-5.7-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fix from David Sterba:
"A regression fix for a warning caused by running balance and snapshot
creation in parallel"
* tag 'for-5.7-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix setting last_trans for reloc roots
I made a mistake with my previous fix, I assumed that we didn't need to
mess with the reloc roots once we were out of the part of relocation where
we are actually moving the extents.
The subtle thing that I missed is that btrfs_init_reloc_root() also
updates the last_trans for the reloc root when we do
btrfs_record_root_in_trans() for the corresponding fs_root. I've added a
comment to make sure future me doesn't make this mistake again.
This showed up as a WARN_ON() in btrfs_copy_root() because our
last_trans didn't == the current transid. This could happen if we
snapshotted a fs root with a reloc root after we set
rc->create_reloc_tree = 0, but before we actually merge the reloc root.
Worth mentioning that the regression produced the following warning
when running snapshot creation and balance in parallel:
BTRFS info (device sdc): relocating block group 30408704 flags metadata|dup
------------[ cut here ]------------
WARNING: CPU: 0 PID: 12823 at fs/btrfs/ctree.c:191 btrfs_copy_root+0x26f/0x430 [btrfs]
CPU: 0 PID: 12823 Comm: btrfs Tainted: G W 5.6.0-rc7-btrfs-next-58 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
RIP: 0010:btrfs_copy_root+0x26f/0x430 [btrfs]
RSP: 0018:ffffb96e044279b8 EFLAGS: 00010202
RAX: 0000000000000009 RBX: ffff9da70bf61000 RCX: ffffb96e04427a48
RDX: ffff9da733a770c8 RSI: ffff9da70bf61000 RDI: ffff9da694163818
RBP: ffff9da733a770c8 R08: fffffffffffffff8 R09: 0000000000000002
R10: ffffb96e044279a0 R11: 0000000000000000 R12: ffff9da694163818
R13: fffffffffffffff8 R14: ffff9da6d2512000 R15: ffff9da714cdac00
FS: 00007fdeacf328c0(0000) GS:ffff9da735e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055a2a5b8a118 CR3: 00000001eed78002 CR4: 00000000003606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
? create_reloc_root+0x49/0x2b0 [btrfs]
? kmem_cache_alloc_trace+0xe5/0x200
create_reloc_root+0x8b/0x2b0 [btrfs]
btrfs_reloc_post_snapshot+0x96/0x5b0 [btrfs]
create_pending_snapshot+0x610/0x1010 [btrfs]
create_pending_snapshots+0xa8/0xd0 [btrfs]
btrfs_commit_transaction+0x4c7/0xc50 [btrfs]
? btrfs_mksubvol+0x3cd/0x560 [btrfs]
btrfs_mksubvol+0x455/0x560 [btrfs]
__btrfs_ioctl_snap_create+0x15f/0x190 [btrfs]
btrfs_ioctl_snap_create_v2+0xa4/0xf0 [btrfs]
? mem_cgroup_commit_charge+0x6e/0x540
btrfs_ioctl+0x12d8/0x3760 [btrfs]
? do_raw_spin_unlock+0x49/0xc0
? _raw_spin_unlock+0x29/0x40
? __handle_mm_fault+0x11b3/0x14b0
? ksys_ioctl+0x92/0xb0
ksys_ioctl+0x92/0xb0
? trace_hardirqs_off_thunk+0x1a/0x1c
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x5c/0x280
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fdeabd3bdd7
Fixes: 2abc726ab4 ("btrfs: do not init a reloc root if we aren't relocating")
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
for invalid pointer dereference and uninitialized variable use on
asynchronous create and unlink error paths.
-----BEGIN PGP SIGNATURE-----
iQFHBAABCAAxFiEEydHwtzie9C7TfviiSn/eOAIR84sFAl6YkKMTHGlkcnlvbW92
QGdtYWlsLmNvbQAKCRBKf944AhHzi9mfCACM7yEZA3rYEUzoUVO2MfaZOnbPVyFe
0tRZB2Fcu5nzJLibeTMX8e0OKb0KtEpPcJXw8EMIe/IRA4ahUUCHp7cCe+jIoPuX
OB9JLOD0tgQJ1jt7hAd7SZFkN/iCJ/jpF/9kSD/8cLHUmPy2g2QzUtSeEtuRfsXD
8jOxW9heOIFVpysUC8HHsRO+b7yPL8AguG8WXNoDItL9uB1DmrgkxOhh/ijqPxVz
F9Du3WlEPzdOTheU6pxtTAMdds4mq3ltBnUElCevR4qY0og4YaqDwnGf0pJlzSuN
nVvAhSSOGbVdvkjzTaPo2BF5rEYXNm6Hln0HGHsUubnDlFZ200GbFEJk
=b1jf
-----END PGP SIGNATURE-----
Merge tag 'ceph-for-5.7-rc2' of git://github.com/ceph/ceph-client
Pull ceph fixes from Ilya Dryomov:
- a set of patches for a deadlock on "rbd map" error path
- a fix for invalid pointer dereference and uninitialized variable use
on asynchronous create and unlink error paths.
* tag 'ceph-for-5.7-rc2' of git://github.com/ceph/ceph-client:
ceph: fix potential bad pointer deref in async dirops cb's
rbd: don't mess with a page vector in rbd_notify_op_lock()
rbd: don't test rbd_dev->opts in rbd_dev_image_release()
rbd: call rbd_dev_unprobe() after unwatching and flushing notifies
rbd: avoid a deadlock on header_rwsem when flushing notifies
A dump_stack call for signature related errors can be too noisy
and not of much value in debugging such problems.
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Shyam Prasad N <nspmangalore@gmail.com>
Move the inode dirty data flushing to a workqueue so that multiple
threads can take advantage of a single thread's flushing work. The
ratelimiting technique used in bdd4ee4 was not successful, because
threads that skipped the inode flush scan due to ratelimiting would
ENOSPC early, which caused occasional (but noticeable) changes in
behavior and sporadic fstest regressions.
Therefore, make all the writer threads wait on a single inode flush,
which eliminates both the stampeding hordes of flushers and the small
window in which a write could fail with ENOSPC because it lost the
ratelimit race after even another thread freed space.
Fixes: c6425702f2 ("xfs: ratelimit inode flush on buffered write ENOSPC")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Michael Kerrisk suggested to replace numeric clock IDs with symbolic names.
Now the content of these files looks like this:
$ cat /proc/774/timens_offsets
monotonic 864000 0
boottime 1728000 0
For setting offsets, both representations of clocks (numeric and symbolic)
can be used.
As for compatibility, it is acceptable to change things as long as
userspace doesn't care. The format of timens_offsets files is very new and
there are no userspace tools yet which rely on this format.
But three projects crun, util-linux and criu rely on the interface of
setting time offsets and this is why it's required to continue supporting
the numeric clock IDs on write.
Fixes: 04a8682a71 ("fs/proc: Introduce /proc/pid/timens_offsets")
Suggested-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200411154031.642557-1-avagin@gmail.com
syzbot writes:
> KASAN: use-after-free Read in dput (2)
>
> proc_fill_super: allocate dentry failed
> ==================================================================
> BUG: KASAN: use-after-free in fast_dput fs/dcache.c:727 [inline]
> BUG: KASAN: use-after-free in dput+0x53e/0xdf0 fs/dcache.c:846
> Read of size 4 at addr ffff88808a618cf0 by task syz-executor.0/8426
>
> CPU: 0 PID: 8426 Comm: syz-executor.0 Not tainted 5.6.0-next-20200412-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0x188/0x20d lib/dump_stack.c:118
> print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:382
> __kasan_report.cold+0x35/0x4d mm/kasan/report.c:511
> kasan_report+0x33/0x50 mm/kasan/common.c:625
> fast_dput fs/dcache.c:727 [inline]
> dput+0x53e/0xdf0 fs/dcache.c:846
> proc_kill_sb+0x73/0xf0 fs/proc/root.c:195
> deactivate_locked_super+0x8c/0xf0 fs/super.c:335
> vfs_get_super+0x258/0x2d0 fs/super.c:1212
> vfs_get_tree+0x89/0x2f0 fs/super.c:1547
> do_new_mount fs/namespace.c:2813 [inline]
> do_mount+0x1306/0x1b30 fs/namespace.c:3138
> __do_sys_mount fs/namespace.c:3347 [inline]
> __se_sys_mount fs/namespace.c:3324 [inline]
> __x64_sys_mount+0x18f/0x230 fs/namespace.c:3324
> do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
> entry_SYSCALL_64_after_hwframe+0x49/0xb3
> RIP: 0033:0x45c889
> Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007ffc1930ec48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
> RAX: ffffffffffffffda RBX: 0000000001324914 RCX: 000000000045c889
> RDX: 0000000020000140 RSI: 0000000020000040 RDI: 0000000000000000
> RBP: 000000000076bf00 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
> R13: 0000000000000749 R14: 00000000004ca15a R15: 0000000000000013
Looking at the code now that it the internal mount of proc is no
longer used it is possible to unmount proc. If proc is unmounted
the fields of the pid namespace that were used for filesystem
specific state are not reinitialized.
Which means that proc_self and proc_thread_self can be pointers to
already freed dentries.
The reported user after free appears to be from mounting and
unmounting proc followed by mounting proc again and using error
injection to cause the new root dentry allocation to fail. This in
turn results in proc_kill_sb running with proc_self and
proc_thread_self still retaining their values from the previous mount
of proc. Then calling dput on either proc_self of proc_thread_self
will result in double put. Which KASAN sees as a use after free.
Solve this by always reinitializing the filesystem state stored
in the struct pid_namespace, when proc is unmounted.
Reported-by: syzbot+72868dd424eb66c6b95f@syzkaller.appspotmail.com
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Fixes: 69879c01a0 ("proc: Remove the now unnecessary internal mount of proc")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
If the in-core buddy bitmap gets corrupted (or out of sync with the
block bitmap), issue a WARN_ON and try to recover. In most cases this
involves skipping trying to allocate out of a particular block group.
We can end up declaring the file system corrupted, which is fair,
since the file system probably should be checked before we proceed any
further.
Link: https://lore.kernel.org/r/20200414035649.293164-1-tytso@mit.edu
Google-Bug-Id: 34811296
Google-Bug-Id: 34639169
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Current wait times have proven to be too short to protect against inode
reuses that lead to metadata inconsistencies.
Now that we will retry the inode allocation if we can't find any
recently deleted inodes, it's a lot safer to increase the recently
deleted time from 5 seconds to a minute.
Link: https://lore.kernel.org/r/20200414023925.273867-1-tytso@mit.edu
Google-Bug-Id: 36602237
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Fix the following gcc warning:
fs/ext4/ext4_jbd2.c:341:30: warning: variable 'es' set but not used [-Wunused-but-set-variable]
struct ext4_super_block *es;
^~
Fixes: 2ea2fc775321 ("ext4: save all error info in save_error_info() and drop ext4_set_errno()")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20200402034759.29957-1-yanaijie@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Fix the following gcc warning:
fs/ext4/super.c:599:27: warning: variable 'es' set but not used [-Wunused-but-set-variable]
struct ext4_super_block *es;
^~
Fixes: 2ea2fc775321 ("ext4: save all error info in save_error_info() and drop ext4_set_errno()")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Link: https://lore.kernel.org/r/20200402033939.25303-1-yanaijie@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
We do not want to create initialized extents beyond end of file because
for e2fsck it is impossible to distinguish them from a case of corrupted
file size / extent tree and so it complains like:
Inode 12, i_size is 147456, should be 163840. Fix? no
Code in ext4_ext_convert_to_initialized() and
ext4_split_convert_extents() try to make sure it does not create
initialized extents beyond inode size however they check against
inode->i_size which is wrong. They should instead check against
EXT4_I(inode)->i_disksize which is the current inode size on disk.
That's what e2fsck is going to see in case of crash before all dirty
data is written. This bug manifests as generic/456 test failure (with
recent enough fstests where fsx got fixed to properly pass
FALLOC_KEEP_SIZE_FL flags to the kernel) when run with dioread_lock
mount option.
CC: stable@vger.kernel.org
Fixes: 21ca087a38 ("ext4: Do not zero out uninitialized extents beyond i_size")
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20200331105016.8674-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The documentation comments for ext4_read_block_bitmap_nowait and
ext4_read_inode_bitmap describe them as returning NULL on error, but
they return an ERR_PTR on error; update the documentation to match.
The documentation comment for ext4_wait_block_bitmap describes it as
returning 1 on error, but it returns -errno on error; update the
documentation to match.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Ritesh Harani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/60a3f4996f4932c45515aaa6b75ca42f2a78ec9b.1585512514.git.josh@joshtriplett.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Since commit a8ac900b81 ("ext4: use non-movable memory for the
superblock") buffers for ext4 superblock were allocated using
the sb_bread_unmovable() helper which allocated buffer heads
out of non-movable memory blocks. It was necessarily to not block
page migrations and do not cause cma allocation failures.
However commit 85c8f176a6 ("ext4: preload block group descriptors")
broke this by introducing pre-reading of the ext4 superblock.
The problem is that __breadahead() is using __getblk() underneath,
which allocates buffer heads out of movable memory.
It resulted in page migration failures I've seen on a machine
with an ext4 partition and a preallocated cma area.
Fix this by introducing sb_breadahead_unmovable() and
__breadahead_gfp() helpers which use non-movable memory for buffer
head allocations and use them for the ext4 superblock readahead.
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Fixes: 85c8f176a6 ("ext4: preload block group descriptors")
Signed-off-by: Roman Gushchin <guro@fb.com>
Link: https://lore.kernel.org/r/20200229001411.128010-1-guro@fb.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Run generic/388 with journal data mode sometimes may trigger the warning
in ext4_invalidatepage. Actually, we should use the matching invalidatepage
in ext4_writepage.
Signed-off-by: yangerkun <yangerkun@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200226041002.13914-1-yangerkun@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Found a read performance issue when linux kernel page size is 64KB.
If linux kernel page size is 64KB and mount options cache=strict &
vers=2.1+, it does not support cifs_readpages(). Instead, it is using
cifs_readpage() and cifs_read() with maximum read IO size 16KB, which is
much slower than read IO size 1MB when negotiated SMB 2.1+. Since modern
SMB server supported SMB 2.1+ and Max Read Size can reach more than 64KB
(for example 1MB ~ 8MB), this patch check max_read instead of maxBuf to
determine whether server support readpages() and improve read performance
for page size 64KB & cache=strict & vers=2.1+, and for SMB1 it is more
cleaner to initialize server->max_read to server->maxBuf.
The client is a linux box with linux kernel 4.2.8,
page size 64KB (CONFIG_ARM64_64K_PAGES=y),
cpu arm 1.7GHz, and use mount.cifs as smb client.
The server is another linux box with linux kernel 4.2.8,
share a file '10G.img' with size 10GB,
and use samba-4.7.12 as smb server.
The client mount a share from the server with different
cache options: cache=strict and cache=none,
mount -tcifs //<server_ip>/Public /cache_strict -overs=3.0,cache=strict,username=<xxx>,password=<yyy>
mount -tcifs //<server_ip>/Public /cache_none -overs=3.0,cache=none,username=<xxx>,password=<yyy>
The client download a 10GbE file from the server across 1GbE network,
dd if=/cache_strict/10G.img of=/dev/null bs=1M count=10240
dd if=/cache_none/10G.img of=/dev/null bs=1M count=10240
Found that cache=strict (without patch) is slower read throughput and
smaller read IO size than cache=none.
cache=strict (without patch): read throughput 40MB/s, read IO size is 16KB
cache=strict (with patch): read throughput 113MB/s, read IO size is 1MB
cache=none: read throughput 109MB/s, read IO size is 1MB
Looks like if page size is 64KB,
cifs_set_ops() would use cifs_addr_ops_smallbuf instead of cifs_addr_ops,
/* check if server can support readpages */
if (cifs_sb_master_tcon(cifs_sb)->ses->server->maxBuf <
PAGE_SIZE + MAX_CIFS_HDR_SIZE)
inode->i_data.a_ops = &cifs_addr_ops_smallbuf;
else
inode->i_data.a_ops = &cifs_addr_ops;
maxBuf is came from 2 places, SMB2_negotiate() and CIFSSMBNegotiate(),
(SMB2_MAX_BUFFER_SIZE is 64KB)
SMB2_negotiate():
/* set it to the maximum buffer size value we can send with 1 credit */
server->maxBuf = min_t(unsigned int, le32_to_cpu(rsp->MaxTransactSize),
SMB2_MAX_BUFFER_SIZE);
CIFSSMBNegotiate():
server->maxBuf = le32_to_cpu(pSMBr->MaxBufferSize);
Page size 64KB and cache=strict lead to read_pages() use cifs_readpage()
instead of cifs_readpages(), and then cifs_read() using maximum read IO
size 16KB, which is much slower than maximum read IO size 1MB.
(CIFSMaxBufSize is 16KB by default)
/* FIXME: set up handlers for larger reads and/or convert to async */
rsize = min_t(unsigned int, cifs_sb->rsize, CIFSMaxBufSize);
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Jones Syue <jonessyue@qnap.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
We already dump these keys for SMB3, lets also dump it for SMB2
sessions so that we can use the session key in wireshark to check and validate
that the signatures are correct.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
When checking for draining with __req_need_defer(), it tries to match
how many requests were sent before a current one with number of already
completed. Dropped SQEs are included in req->sequence, and they won't
ever appear in CQ. To compensate for that, __req_need_defer() substracts
ctx->cached_sq_dropped.
However, what it should really use is number of SQEs dropped __before__
the current one. In other words, any submitted request shouldn't
shouldn't affect dequeueing from the drain queue of previously submitted
ones.
Instead of saving proper ctx->cached_sq_dropped in each request,
substract from req->sequence it at initialisation, so it includes number
of properly submitted requests.
note: it also changes behaviour of timeouts, but
1. it's already diverge from the description because of using SQ
2. the description is ambiguous regarding dropped SQEs
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
req->timeout.count and req->io->timeout.seq_offset store the same value,
which is sqe->off. Kill the second one
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
io_timeout() can be executed asynchronously by a worker and without
holding ctx->uring_lock
1. using ctx->cached_sq_head there is racy there
2. it should count events from a moment of timeout's submission, but
not execution
Use req->sequence.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
-----BEGIN PGP SIGNATURE-----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=pkZ2
-----END PGP SIGNATURE-----
Merge tag 'for-5.7-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"We have a few regressions and one fix for stable:
- revert fsync optimization
- fix lost i_size update
- fix a space accounting leak
- build fix, add back definition of a deprecated ioctl flag
- fix search condition for old roots in relocation"
* tag 'for-5.7-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: re-instantiate the removed BTRFS_SUBVOL_CREATE_ASYNC definition
btrfs: fix reclaim counter leak of space_info objects
btrfs: make full fsyncs always operate on the entire file again
btrfs: fix lost i_size update after cloning inline extent
btrfs: check commit root generation in should_ignore_root
We need to drop the inode spinlock while calling nfs4_select_rw_stateid(),
since nfs4_copy_delegation_stateid() could take the delegation lock.
Note that it is safe to do this, since all other calls to
pnfs_update_layout() for that inode will find themselves blocked by
the lock we hold on NFS_LAYOUT_FIRST_LAYOUTGET.
Fixes: fc51b1cf39 ("NFS: Beware when dereferencing the delegation cred")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
The new async dirops callback routines can pass ERR_PTR values to
ceph_mdsc_free_path, which could cause an oops. Make ceph_mdsc_free_path
ignore ERR_PTR values. Also, ensure that the pr_warn messages look sane
even if ceph_mdsc_build_path fails.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
If the request has been marked as canceled, don't try and issue it.
Instead just fill a canceled event and finish the request.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We added this for just the regular poll requests in commit a6ba632d2c
("io_uring: retry poll if we got woken with non-matching mask"), we
should do the same for the poll handler used pollable async requests.
Move the re-wait check and arm into a helper, and call it from
io_async_task_func() as well.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
In the reflink extent remap function, it turns out that uirec (the block
mapping corresponding only to the part of the passed-in mapping that got
unmapped) was not fully initialized. Specifically, br_state was not
being copied from the passed-in struct to the uirec. This could lead to
unpredictable results such as the reflinked mapping being marked
unwritten in the destination file.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
The filesystem freeze sequence in XFS waits on any background
eofblocks or cowblocks scans to complete before the filesystem is
quiesced. At this point, the freezer has already stopped the
transaction subsystem, however, which means a truncate or cowblock
cancellation in progress is likely blocked in transaction
allocation. This results in a deadlock between freeze and the
associated scanner.
Fix this problem by holding superblock write protection across calls
into the block reapers. Since protection for background scans is
acquired from the workqueue task context, trylock to avoid a similar
deadlock between freeze and blocking on the write lock.
Fixes: d6b636ebb1 ("xfs: halt auto-reclamation activities while rebuilding rmap")
Reported-by: Paul Furtado <paulfurtado91@gmail.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
If a dentry's version is somewhere between invalid_before and the current
directory version, we should be setting it forward to the current version,
not backwards to the invalid_before version. Note that we're only doing
this at all because dentry::d_fsdata isn't large enough on a 32-bit system.
Fix this by using a separate variable for invalid_before so that we don't
accidentally clobber the current dir version.
Fixes: a4ff7401fb ("afs: Keep track of invalid-before version for dentry coherency")
Signed-off-by: David Howells <dhowells@redhat.com>
AFS directories are retained locally as a structured file, with lookup
being effected by a local search of the file contents. When a modification
(such as mkdir) happens, the dir file content is modified locally rather
than redownloading the directory.
The directory contents are accessed in a number of ways, with a number of
different locks schemes:
(1) Download of contents - dvnode->validate_lock/write in afs_read_dir().
(2) Lookup and readdir - dvnode->validate_lock/read in afs_dir_iterate(),
downgrading from (1) if necessary.
(3) d_revalidate of child dentry - dvnode->validate_lock/read in
afs_do_lookup_one() downgrading from (1) if necessary.
(4) Edit of dir after modification - page locks on individual dir pages.
Unfortunately, because (4) uses different locking scheme to (1) - (3),
nothing protects against the page being scanned whilst the edit is
underway. Even download is not safe as it doesn't lock the pages - relying
instead on the validate_lock to serialise as a whole (the theory being that
directory contents are treated as a block and always downloaded as a
block).
Fix this by write-locking dvnode->validate_lock around the edits. Care
must be taken in the rename case as there may be two different dirs - but
they need not be locked at the same time. In any case, once the lock is
taken, the directory version must be rechecked, and the edit skipped if a
later version has been downloaded by revalidation (there can't have been
any local changes because the VFS holds the inode lock, but there can have
been remote changes).
Fixes: 63a4681ff3 ("afs: Locally edit directory data for mkdir/create/unlink/...")
Signed-off-by: David Howells <dhowells@redhat.com>
Miklos Szeredi