68258 Commits

Author SHA1 Message Date
J. Bruce Fields
9f70460801 nfs: we don't support removing system.nfs4_acl
[ Upstream commit 4f8be1f53bf615102d103c0509ffa9596f65b718 ]

The NFSv4 protocol doesn't have any notion of reomoving an attribute, so
removexattr(path,"system.nfs4_acl") doesn't make sense.

There's no documented return value.  Arguably it could be EOPNOTSUPP but
I'm a little worried an application might take that to mean that we
don't support ACLs or xattrs.  How about EINVAL?

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:31:52 +02:00
Paulo Alcantara
b684c380f0 cifs: change noisy error message to FYI
[ Upstream commit e3d100eae44b42f309c1366efb8397368f1cf8ed ]

A customer has reported that their dmesg were being flooded by

  CIFS: VFS: \\server Cancelling wait for mid xxx cmd: a
  CIFS: VFS: \\server Cancelling wait for mid yyy cmd: b
  CIFS: VFS: \\server Cancelling wait for mid zzz cmd: c

because some processes that were performing statfs(2) on the share had
been interrupted due to their automount setup when certain users
logged in and out.

Change it to FYI as they should be mostly informative rather than
error messages.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:31:50 +02:00
Frank Sorenson
9d1a5392ac NFS: Correct size calculation for create reply length
[ Upstream commit ad3dbe35c833c2d4d0bbf3f04c785d32f931e7c9 ]

CREATE requests return a post_op_fh3, rather than nfs_fh3. The
post_op_fh3 includes an extra word to indicate 'handle_follows'.

Without that additional word, create fails when full 64-byte
filehandles are in use.

Add NFS3_post_op_fh_sz, and correct the size calculation for
NFS3_createres_sz.

Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:31:49 +02:00
Timo Rothenpieler
2479c6b9ef nfs: fix PNFS_FLEXFILE_LAYOUT Kconfig default
[ Upstream commit a0590473c5e6c4ef17c3132ad08fbad170f72d55 ]

This follows what was done in 8c2fabc6542d9d0f8b16bd1045c2eda59bdcde13.
With the default being m, it's impossible to build the module into the
kernel.

Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:31:49 +02:00
Bob Peterson
6d7dce3bdf gfs2: fix use-after-free in trans_drain
[ Upstream commit 1a5a2cfd34c17db73c53ef127272c8c1ae220485 ]

This patch adds code to function trans_drain to remove drained
bd elements from the ail lists, if queued, before freeing the bd.
If we don't remove the bd from the ail, function ail_drain will
try to reference the bd after it has been freed by trans_drain.

Thanks to Andy Price for his analysis of the problem.

Reported-by: Andy Price <anprice@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:31:49 +02:00
Aurelien Aptel
419ebba40d cifs: ask for more credit on async read/write code paths
[ Upstream commit 88fd98a2306755b965e4f4567f84e73db3b6738c ]

When doing a large read or write workload we only
very gradually increase the number of credits
which can cause problems with parallelizing large i/o
(I/O ramps up more slowly than it should for large
read/write workloads) especially with multichannel
when the number of credits on the secondary channels
starts out low (e.g. less than about 130) or when
recovering after server throttled back the number
of credit.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-30 14:31:49 +02:00
Vincent Whitchurch
de1126ea44 cifs: Fix preauth hash corruption
commit 05946d4b7a7349ae58bfa2d51ae832e64a394c2d upstream.

smb311_update_preauth_hash() uses the shash in server->secmech without
appropriate locking, and this can lead to sessions corrupting each
other's preauth hashes.

The following script can easily trigger the problem:

	#!/bin/sh -e

	NMOUNTS=10
	for i in $(seq $NMOUNTS);
		mkdir -p /tmp/mnt$i
		umount /tmp/mnt$i 2>/dev/null || :
	done
	while :; do
		for i in $(seq $NMOUNTS); do
			mount -t cifs //192.168.0.1/test /tmp/mnt$i -o ... &
		done
		wait
		for i in $(seq $NMOUNTS); do
			umount /tmp/mnt$i
		done
	done

Usually within seconds this leads to one or more of the mounts failing
with the following errors, and a "Bad SMB2 signature for message" is
seen in the server logs:

 CIFS: VFS: \\192.168.0.1 failed to connect to IPC (rc=-13)
 CIFS: VFS: cifs_mount failed w/return code = -13

Fix it by holding the server mutex just like in the other places where
the shashes are used.

Fixes: 8bd68c6e47abff34e4 ("CIFS: implement v3.11 preauth integrity")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
CC: <stable@vger.kernel.org>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
[aaptel: backport to kernel without CIFS_SESS_OP]
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:18 +01:00
Harshad Shirwadkar
35ecf664fd ext4: fix rename whiteout with fast commit
commit 8210bb29c1b66200cff7b25febcf6e39baf49fbf upstream.

This patch adds rename whiteout support in fast commits. Note that the
whiteout object that gets created is actually char device. Which
imples, the function ext4_inode_journal_mode(struct inode *inode)
would return "JOURNAL_DATA" for this inode. This has a consequence in
fast commit code that it will make creation of the whiteout object a
fast-commit ineligible behavior and thus will fall back to full
commits. With this patch, this can be observed by running fast commits
with rename whiteout and seeing the stats generated by ext4_fc_stats
tracepoint as follows:

ext4_fc_stats: dev 254:32 fc ineligible reasons:
XATTR:0, CROSS_RENAME:0, JOURNAL_FLAG_CHANGE:0, NO_MEM:0, SWAP_BOOT:0,
RESIZE:0, RENAME_DIR:0, FALLOC_RANGE:0, INODE_JOURNAL_DATA:16;
num_commits:6, ineligible: 6, numblks: 3

So in short, this patch guarantees that in case of rename whiteout, we
fall back to full commits.

Amir mentioned that instead of creating a new whiteout object for
every rename, we can create a static whiteout object with irrelevant
nlink. That will make fast commits to not fall back to full
commit. But until this happens, this patch will ensure correctness by
falling back to full commits.

Fixes: 8016e29f4362 ("ext4: fast commit recovery path")
Cc: stable@kernel.org
Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20210316221921.1124955-1-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:17 +01:00
Shijie Luo
e8fa569465 ext4: fix potential error in ext4_do_update_inode
commit 7d8bd3c76da1d94b85e6c9b7007e20e980bfcfe6 upstream.

If set_large_file = 1 and errors occur in ext4_handle_dirty_metadata(),
the error code will be overridden, go to out_brelse to avoid this
situation.

Signed-off-by: Shijie Luo <luoshijie1@huawei.com>
Link: https://lore.kernel.org/r/20210312065051.36314-1-luoshijie1@huawei.com
Cc: stable@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:17 +01:00
zhangyi (F)
6163a0662b ext4: do not try to set xattr into ea_inode if value is empty
commit 6b22489911b726eebbf169caee52fea52013fbdd upstream.

Syzbot report a warning that ext4 may create an empty ea_inode if set
an empty extent attribute to a file on the file system which is no free
blocks left.

  WARNING: CPU: 6 PID: 10667 at fs/ext4/xattr.c:1640 ext4_xattr_set_entry+0x10f8/0x1114 fs/ext4/xattr.c:1640
  ...
  Call trace:
   ext4_xattr_set_entry+0x10f8/0x1114 fs/ext4/xattr.c:1640
   ext4_xattr_block_set+0x1d0/0x1b1c fs/ext4/xattr.c:1942
   ext4_xattr_set_handle+0x8a0/0xf1c fs/ext4/xattr.c:2390
   ext4_xattr_set+0x120/0x1f0 fs/ext4/xattr.c:2491
   ext4_xattr_trusted_set+0x48/0x5c fs/ext4/xattr_trusted.c:37
   __vfs_setxattr+0x208/0x23c fs/xattr.c:177
  ...

Now, ext4 try to store extent attribute into an external inode if
ext4_xattr_block_set() return -ENOSPC, but for the case of store an
empty extent attribute, store the extent entry into the extent
attribute block is enough. A simple reproduce below.

  fallocate test.img -l 1M
  mkfs.ext4 -F -b 2048 -O ea_inode test.img
  mount test.img /mnt
  dd if=/dev/zero of=/mnt/foo bs=2048 count=500
  setfattr -n "user.test" /mnt/foo

Reported-by: syzbot+98b881fdd8ebf45ab4ae@syzkaller.appspotmail.com
Fixes: 9c6e7853c531 ("ext4: reserve space for xattr entries/names")
Cc: stable@kernel.org
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20210305120508.298465-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:17 +01:00
Pan Bian
d130b802f9 ext4: stop inode update before return
commit 512c15ef05d73a04f1aef18a3bc61a8bb516f323 upstream.

The inode update should be stopped before returing the error code.

Signed-off-by: Pan Bian <bianpan2016@163.com>
Link: https://lore.kernel.org/r/20210117085732.93788-1-bianpan2016@163.com
Fixes: 8016e29f4362 ("ext4: fast commit recovery path")
Cc: stable@kernel.org
Reviewed-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:17 +01:00
zhangyi (F)
258db8e6ff ext4: find old entry again if failed to rename whiteout
commit b7ff91fd030dc9d72ed91b1aab36e445a003af4f upstream.

If we failed to add new entry on rename whiteout, we cannot reset the
old->de entry directly, because the old->de could have moved from under
us during make indexed dir. So find the old entry again before reset is
needed, otherwise it may corrupt the filesystem as below.

  /dev/sda: Entry '00000001' in ??? (12) has deleted/unused inode 15. CLEARED.
  /dev/sda: Unattached inode 75
  /dev/sda: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.

Fixes: 6b4b8e6b4ad ("ext4: fix bug for rename with RENAME_WHITEOUT")
Cc: stable@vger.kernel.org
Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20210303131703.330415-1-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:17 +01:00
Eric Biggers
9689ecadf8 ext4: fix error handling in ext4_end_enable_verity()
commit f053cf7aa66cd9d592b0fc967f4d887c2abff1b7 upstream.

ext4 didn't properly clean up if verity failed to be enabled on a file:

- It left verity metadata (pages past EOF) in the page cache, which
  would be exposed to userspace if the file was later extended.

- It didn't truncate the verity metadata at all (either from cache or
  from disk) if an error occurred while setting the verity bit.

Fix these bugs by adding a call to truncate_inode_pages() and ensuring
that we truncate the verity metadata (both from cache and from disk) in
all error paths.  Also rework the code to cleanly separate the success
path from the error paths, which makes it much easier to understand.

Reported-by: Yunlei He <heyunlei@hihonor.com>
Fixes: c93d8f885809 ("ext4: add basic fs-verity support")
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20210302200420.137977-2-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:17 +01:00
Oleg Nesterov
4523e648b7 kernel, fs: Introduce and use set_restart_fn() and arch_set_restart_data()
commit 5abbe51a526253b9f003e9a0a195638dc882d660 upstream.

Preparation for fixing get_nr_restart_syscall() on X86 for COMPAT.

Add a new helper which sets restart_block->fn and calls a dummy
arch_set_restart_data() helper.

Fixes: 609c19a385c8 ("x86/ptrace: Stop setting TS_COMPAT in ptrace code")
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210201174641.GA17871@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:16 +01:00
Bob Peterson
2bdef2b476 gfs2: bypass signal_our_withdraw if no journal
[ Upstream commit d5bf630f355d8c532bef2347cf90e8ae60a5f1bd ]

Before this patch, function signal_our_withdraw referenced the journal
inode immediately. But corrupt file systems may have some invalid
journals, in which case our attempt to read it in will withdraw and the
resulting signal_our_withdraw would dereference the NULL value.

This patch adds a check to signal_our_withdraw so that if the journal
has not yet been initialized, it simply returns and does the old-style
withdraw.

Thanks, Andy Price, for his analysis.

Reported-by: syzbot+50a8a9cf8127f2c6f5df@syzkaller.appspotmail.com
Fixes: 601ef0d52e96 ("gfs2: Force withdraw to replay journals and wait for it to finish")
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-25 09:04:14 +01:00
Bob Peterson
a602e830dd gfs2: move freeze glock outside the make_fs_rw and _ro functions
[ Upstream commit 96b1454f2e8ede4c619fde405a1bb4e9ba8d218e ]

Before this patch, sister functions gfs2_make_fs_rw and gfs2_make_fs_ro locked
(held) the freeze glock by calling gfs2_freeze_lock and gfs2_freeze_unlock.
The problem is, not all the callers of gfs2_make_fs_ro should be doing this.
The three callers of gfs2_make_fs_ro are: remount (gfs2_reconfigure),
signal_our_withdraw, and unmount (gfs2_put_super). But when unmounting the
file system we can get into the following circular lock dependency:

deactivate_super
   down_write(&s->s_umount); <-------------------------------------- s_umount
   deactivate_locked_super
      gfs2_kill_sb
         kill_block_super
            generic_shutdown_super
               gfs2_put_super
                  gfs2_make_fs_ro
                     gfs2_glock_nq_init sd_freeze_gl
                        freeze_go_sync
                           if (freeze glock in SH)
                              freeze_super (vfs)
                                 down_write(&sb->s_umount); <------- s_umount

This patch moves the hold of the freeze glock outside the two sister rw/ro
functions to their callers, but it doesn't request the glock from
gfs2_put_super, thus eliminating the circular dependency.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-25 09:04:14 +01:00
Bob Peterson
49787b1bba gfs2: Add common helper for holding and releasing the freeze glock
[ Upstream commit c77b52c0a137994ad796f44544c802b0b766e496 ]

Many places in the gfs2 code queued and dequeued the freeze glock.
Almost all of them acquire it in SHARED mode, and need to specify the
same LM_FLAG_NOEXP and GL_EXACT flags.

This patch adds common helper functions gfs2_freeze_lock and gfs2_freeze_unlock
to make the code more readable, and to prepare for the next patch.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-25 09:04:14 +01:00
Jens Axboe
76f496681d io_uring: clear IOCB_WAITQ for non -EIOCBQUEUED return
[ Upstream commit b5b0ecb736f1ce1e68eb50613c0cfecff10198eb ]

The callback can only be armed, if we get -EIOCBQUEUED returned. It's
important that we clear the WAITQ bit for other cases, otherwise we can
queue for async retry and filemap will assume that we're armed and
return -EAGAIN instead of just blocking for the IO.

Cc: stable@vger.kernel.org # 5.9+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-25 09:04:13 +01:00
Jens Axboe
3c08f772ad io_uring: don't attempt IO reissue from the ring exit path
[ Upstream commit 7c977a58dc83366e488c217fd88b1469d242bee5 ]

If we're exiting the ring, just let the IO fail with -EAGAIN as nobody
will care anyway. It's not the right context to reissue from.

Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-25 09:04:13 +01:00
Pavel Begunkov
1c20e9040f io_uring: fix inconsistent lock state
[ Upstream commit 9ae1f8dd372e0e4c020b345cf9e09f519265e981 ]

WARNING: inconsistent lock state

inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
syz-executor217/8450 [HC1[1]:SC0[0]:HE0:SE1] takes:
ffff888023d6e620 (&fs->lock){?.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:354 [inline]
ffff888023d6e620 (&fs->lock){?.+.}-{2:2}, at: io_req_clean_work fs/io_uring.c:1398 [inline]
ffff888023d6e620 (&fs->lock){?.+.}-{2:2}, at: io_dismantle_req+0x66f/0xf60 fs/io_uring.c:2029

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&fs->lock);
  <Interrupt>
    lock(&fs->lock);

 *** DEADLOCK ***

1 lock held by syz-executor217/8450:
 #0: ffff88802417c3e8 (&ctx->uring_lock){+.+.}-{3:3}, at: __do_sys_io_uring_enter+0x1071/0x1f30 fs/io_uring.c:9442

stack backtrace:
CPU: 1 PID: 8450 Comm: syz-executor217 Not tainted 5.11.0-rc5-next-20210129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
[...]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:354 [inline]
 io_req_clean_work fs/io_uring.c:1398 [inline]
 io_dismantle_req+0x66f/0xf60 fs/io_uring.c:2029
 __io_free_req+0x3d/0x2e0 fs/io_uring.c:2046
 io_free_req fs/io_uring.c:2269 [inline]
 io_double_put_req fs/io_uring.c:2392 [inline]
 io_put_req+0xf9/0x570 fs/io_uring.c:2388
 io_link_timeout_fn+0x30c/0x480 fs/io_uring.c:6497
 __run_hrtimer kernel/time/hrtimer.c:1519 [inline]
 __hrtimer_run_queues+0x609/0xe40 kernel/time/hrtimer.c:1583
 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1102
 asm_call_irq_on_stack+0xf/0x20
 </IRQ>
 __run_sysvec_on_irqstack arch/x86/include/asm/irq_stack.h:37 [inline]
 run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:89 [inline]
 sysvec_apic_timer_interrupt+0xbd/0x100 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:629
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:199
 spin_unlock_irq include/linux/spinlock.h:404 [inline]
 io_queue_linked_timeout+0x194/0x1f0 fs/io_uring.c:6525
 __io_queue_sqe+0x328/0x1290 fs/io_uring.c:6594
 io_queue_sqe+0x631/0x10d0 fs/io_uring.c:6639
 io_queue_link_head fs/io_uring.c:6650 [inline]
 io_submit_sqe fs/io_uring.c:6697 [inline]
 io_submit_sqes+0x19b5/0x2720 fs/io_uring.c:6960
 __do_sys_io_uring_enter+0x107d/0x1f30 fs/io_uring.c:9443
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Don't free requests from under hrtimer context (softirq) as it may sleep
or take spinlocks improperly (e.g. non-irq versions).

Cc: stable@vger.kernel.org # 5.6+
Reported-by: syzbot+81d17233a2b02eafba33@syzkaller.appspotmail.com
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-25 09:04:13 +01:00
Steve French
04eb2b2fa1 cifs: fix allocation size on newly created files
commit 65af8f0166f4d15e61c63db498ec7981acdd897f upstream.

Applications that create and extend and write to a file do not
expect to see 0 allocation size.  When file is extended,
set its allocation size to a plausible value until we have a
chance to query the server for it.  When the file is cached
this will prevent showing an impossible number of allocated
blocks (like 0).  This fixes e.g. xfstests 614 which does

    1) create a file and set its size to 64K
    2) mmap write 64K to the file
    3) stat -c %b for the file (to query the number of allocated blocks)

It was failing because we returned 0 blocks.  Even though we would
return the correct cached file size, we returned an impossible
allocation size.

Signed-off-by: Steve French <stfrench@microsoft.com>
CC: <stable@vger.kernel.org>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:09 +01:00
Jens Axboe
6cae809549 io_uring: ensure that SQPOLL thread is started for exit
commit 3ebba796fa251d042be42b929a2d916ee5c34a49 upstream.

If we create it in a disabled state because IORING_SETUP_R_DISABLED is
set on ring creation, we need to ensure that we've kicked the thread if
we're exiting before it's been explicitly disabled. Otherwise we can run
into a deadlock where exit is waiting go park the SQPOLL thread, but the
SQPOLL thread itself is waiting to get a signal to start.

That results in the below trace of both tasks hung, waiting on each other:

INFO: task syz-executor458:8401 blocked for more than 143 seconds.
      Not tainted 5.11.0-next-20210226-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor458 state:D stack:27536 pid: 8401 ppid:  8400 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4324 [inline]
 __schedule+0x90c/0x21a0 kernel/sched/core.c:5075
 schedule+0xcf/0x270 kernel/sched/core.c:5154
 schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x168/0x270 kernel/sched/completion.c:138
 io_sq_thread_park fs/io_uring.c:7115 [inline]
 io_sq_thread_park+0xd5/0x130 fs/io_uring.c:7103
 io_uring_cancel_task_requests+0x24c/0xd90 fs/io_uring.c:8745
 __io_uring_files_cancel+0x110/0x230 fs/io_uring.c:8840
 io_uring_files_cancel include/linux/io_uring.h:47 [inline]
 do_exit+0x299/0x2a60 kernel/exit.c:780
 do_group_exit+0x125/0x310 kernel/exit.c:922
 __do_sys_exit_group kernel/exit.c:933 [inline]
 __se_sys_exit_group kernel/exit.c:931 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:931
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x43e899
RSP: 002b:00007ffe89376d48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00000000004af2f0 RCX: 000000000043e899
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffc0 R09: 0000000010000000
R10: 0000000000008011 R11: 0000000000000246 R12: 00000000004af2f0
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000001
INFO: task iou-sqp-8401:8402 can't die for more than 143 seconds.
task:iou-sqp-8401    state:D stack:30272 pid: 8402 ppid:  8400 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4324 [inline]
 __schedule+0x90c/0x21a0 kernel/sched/core.c:5075
 schedule+0xcf/0x270 kernel/sched/core.c:5154
 schedule_timeout+0x1db/0x250 kernel/time/timer.c:1868
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x168/0x270 kernel/sched/completion.c:138
 io_sq_thread+0x27d/0x1ae0 fs/io_uring.c:6717
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
INFO: task iou-sqp-8401:8402 blocked for more than 143 seconds.

Reported-by: syzbot+fb5458330b4442f2090d@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:09 +01:00
Tetsuo Handa
a7acb61428 pstore: Fix warning in pstore_kill_sb()
commit 9c7d83ae6ba67d6c6199cce24573983db3b56332 upstream.

syzbot is hitting WARN_ON(pstore_sb != sb) at pstore_kill_sb() [1], for the
assumption that pstore_sb != NULL is wrong because pstore_fill_super() will
not assign pstore_sb = sb when new_inode() for d_make_root() returned NULL
(due to memory allocation fault injection).

Since mount_single() calls pstore_kill_sb() when pstore_fill_super()
failed, pstore_kill_sb() needs to be aware of such failure path.

[1] https://syzkaller.appspot.com/bug?id=6abacb8da5137cb47a416f2bef95719ed60508a0

Reported-by: syzbot <syzbot+d0cf0ad6513e9a1da5df@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210214031307.57903-1-penguin-kernel@I-love.SAKURA.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:08 +01:00
Olga Kornievskaia
982b899ba6 NFSD: fix dest to src mount in inter-server COPY
commit 614c9750173e412663728215152cc6d12bcb3425 upstream.

A cleanup of the inter SSC copy needs to call fput() of the source
file handle to make sure that file structure is freed as well as
drop the reference on the superblock to unmount the source server.

Fixes: 36e1e5ba90fb ("NFSD: Fix use-after-free warning when doing inter-server copy")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:08 +01:00
J. Bruce Fields
12628e7779 nfsd: don't abort copies early
commit bfdd89f232aa2de5a4b3fc985cba894148b830a8 upstream.

The typical result of the backwards comparison here is that the source
server in a server-to-server copy will return BAD_STATEID within a few
seconds of the copy starting, instead of giving the copy a full lease
period, so the copy_file_range() call will end up unnecessarily
returning a short read.

Fixes: 624322f1adc5 "NFSD add COPY_NOTIFY operation"
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:08 +01:00
Trond Myklebust
5ea0aa29ad nfsd: Don't keep looking up unhashed files in the nfsd file cache
commit d30881f573e565ebb5dbb50b31ed6106b5c81328 upstream.

If a file is unhashed, then we're going to reject it anyway and retry,
so make sure we skip it when we're doing the RCU lockless lookup.
This avoids a number of unnecessary nfserr_jukebox returns from
nfsd_file_acquire()

Fixes: 65294c1f2c5e ("nfsd: add a new struct file caching facility to nfsd")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:08 +01:00
David Howells
64195f022a afs: Stop listxattr() from listing "afs.*" attributes
commit a7889c6320b9200e3fe415238f546db677310fa9 upstream.

afs_listxattr() lists all the available special afs xattrs (i.e. those in
the "afs.*" space), no matter what type of server we're dealing with.  But
OpenAFS servers, for example, cannot deal with some of the extra-capable
attributes that AuriStor (YFS) servers provide.  Unfortunately, the
presence of the afs.yfs.* attributes causes errors[1] for anything that
tries to read them if the server is of the wrong type.

Fix the problem by removing afs_listxattr() so that none of the special
xattrs are listed (AFS doesn't support xattrs).  It does mean, however,
that getfattr won't list them, though they can still be accessed with
getxattr() and setxattr().

This can be tested with something like:

	getfattr -d -m ".*" /afs/example.com/path/to/file

With this change, none of the afs.* attributes should be visible.

Changes:
ver #2:
 - Hide all of the afs.* xattrs, not just the ACL ones.

Fixes: ae46578b963f ("afs: Get YFS ACLs and information through xattrs")
Reported-by: Gaja Sophie Peters <gaja.peters@math.uni-hamburg.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Gaja Sophie Peters <gaja.peters@math.uni-hamburg.de>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003502.html [1]
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003567.html # v1
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003573.html # v2
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:07 +01:00
David Howells
78ba4793b0 afs: Fix accessing YFS xattrs on a non-YFS server
commit 64fcbb6158ecc684d84c64424830a9c37c77c5b9 upstream.

If someone attempts to access YFS-related xattrs (e.g. afs.yfs.acl) on a
file on a non-YFS AFS server (such as OpenAFS), then the kernel will jump
to a NULL function pointer because the afs_fetch_acl_operation descriptor
doesn't point to a function for issuing an operation on a non-YFS
server[1].

Fix this by making afs_wait_for_operation() check that the issue_afs_rpc
method is set before jumping to it and setting -ENOTSUPP if not.  This fix
also covers other potential operations that also only exist on YFS servers.

afs_xattr_get/set_yfs() then need to translate -ENOTSUPP to -ENODATA as the
former error is internal to the kernel.

The bug shows up as an oops like the following:

	BUG: kernel NULL pointer dereference, address: 0000000000000000
	[...]
	Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
	[...]
	Call Trace:
	 afs_wait_for_operation+0x83/0x1b0 [kafs]
	 afs_xattr_get_yfs+0xe6/0x270 [kafs]
	 __vfs_getxattr+0x59/0x80
	 vfs_getxattr+0x11c/0x140
	 getxattr+0x181/0x250
	 ? __check_object_size+0x13f/0x150
	 ? __fput+0x16d/0x250
	 __x64_sys_fgetxattr+0x64/0xb0
	 do_syscall_64+0x49/0xc0
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9
	RIP: 0033:0x7fb120a9defe

This was triggered with "cp -a" which attempts to copy xattrs, including
afs ones, but is easier to reproduce with getfattr, e.g.:

	getfattr -d -m ".*" /afs/openafs.org/

Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept")
Reported-by: Gaja Sophie Peters <gaja.peters@math.uni-hamburg.de>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Gaja Sophie Peters <gaja.peters@math.uni-hamburg.de>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: linux-afs@lists.infradead.org
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003498.html [1]
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003566.html # v1
Link: http://lists.infradead.org/pipermail/linux-afs/2021-March/003572.html # v2
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:07 +01:00
David Sterba
2c8d6a9474 btrfs: fix slab cache flags for free space tree bitmap
commit 34e49994d0dcdb2d31d4d2908d04f4e9ce57e4d7 upstream.

The free space tree bitmap slab cache is created with SLAB_RED_ZONE but
that's a debugging flag and not always enabled. Also the other slabs are
created with at least SLAB_MEM_SPREAD that we want as well to average
the memory placement cost.

Reported-by: Vlastimil Babka <vbabka@suse.cz>
Fixes: 3acd48507dc4 ("btrfs: fix allocation of free space cache v1 bitmap pages")
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:06 +01:00
Filipe Manana
38ffe9eaeb btrfs: fix race when cloning extent buffer during rewind of an old root
commit dbcc7d57bffc0c8cac9dac11bec548597d59a6a5 upstream.

While resolving backreferences, as part of a logical ino ioctl call or
fiemap, we can end up hitting a BUG_ON() when replaying tree mod log
operations of a root, triggering a stack trace like the following:

  ------------[ cut here ]------------
  kernel BUG at fs/btrfs/ctree.c:1210!
  invalid opcode: 0000 [#1] SMP KASAN PTI
  CPU: 1 PID: 19054 Comm: crawl_335 Tainted: G        W         5.11.0-2d11c0084b02-misc-next+ #89
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
  RIP: 0010:__tree_mod_log_rewind+0x3b1/0x3c0
  Code: 05 48 8d 74 10 (...)
  RSP: 0018:ffffc90001eb70b8 EFLAGS: 00010297
  RAX: 0000000000000000 RBX: ffff88812344e400 RCX: ffffffffb28933b6
  RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff88812344e42c
  RBP: ffffc90001eb7108 R08: 1ffff11020b60a20 R09: ffffed1020b60a20
  R10: ffff888105b050f9 R11: ffffed1020b60a1f R12: 00000000000000ee
  R13: ffff8880195520c0 R14: ffff8881bc958500 R15: ffff88812344e42c
  FS:  00007fd1955e8700(0000) GS:ffff8881f5600000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007efdb7928718 CR3: 000000010103a006 CR4: 0000000000170ee0
  Call Trace:
   btrfs_search_old_slot+0x265/0x10d0
   ? lock_acquired+0xbb/0x600
   ? btrfs_search_slot+0x1090/0x1090
   ? free_extent_buffer.part.61+0xd7/0x140
   ? free_extent_buffer+0x13/0x20
   resolve_indirect_refs+0x3e9/0xfc0
   ? lock_downgrade+0x3d0/0x3d0
   ? __kasan_check_read+0x11/0x20
   ? add_prelim_ref.part.11+0x150/0x150
   ? lock_downgrade+0x3d0/0x3d0
   ? __kasan_check_read+0x11/0x20
   ? lock_acquired+0xbb/0x600
   ? __kasan_check_write+0x14/0x20
   ? do_raw_spin_unlock+0xa8/0x140
   ? rb_insert_color+0x30/0x360
   ? prelim_ref_insert+0x12d/0x430
   find_parent_nodes+0x5c3/0x1830
   ? resolve_indirect_refs+0xfc0/0xfc0
   ? lock_release+0xc8/0x620
   ? fs_reclaim_acquire+0x67/0xf0
   ? lock_acquire+0xc7/0x510
   ? lock_downgrade+0x3d0/0x3d0
   ? lockdep_hardirqs_on_prepare+0x160/0x210
   ? lock_release+0xc8/0x620
   ? fs_reclaim_acquire+0x67/0xf0
   ? lock_acquire+0xc7/0x510
   ? poison_range+0x38/0x40
   ? unpoison_range+0x14/0x40
   ? trace_hardirqs_on+0x55/0x120
   btrfs_find_all_roots_safe+0x142/0x1e0
   ? find_parent_nodes+0x1830/0x1830
   ? btrfs_inode_flags_to_xflags+0x50/0x50
   iterate_extent_inodes+0x20e/0x580
   ? tree_backref_for_extent+0x230/0x230
   ? lock_downgrade+0x3d0/0x3d0
   ? read_extent_buffer+0xdd/0x110
   ? lock_downgrade+0x3d0/0x3d0
   ? __kasan_check_read+0x11/0x20
   ? lock_acquired+0xbb/0x600
   ? __kasan_check_write+0x14/0x20
   ? _raw_spin_unlock+0x22/0x30
   ? __kasan_check_write+0x14/0x20
   iterate_inodes_from_logical+0x129/0x170
   ? iterate_inodes_from_logical+0x129/0x170
   ? btrfs_inode_flags_to_xflags+0x50/0x50
   ? iterate_extent_inodes+0x580/0x580
   ? __vmalloc_node+0x92/0xb0
   ? init_data_container+0x34/0xb0
   ? init_data_container+0x34/0xb0
   ? kvmalloc_node+0x60/0x80
   btrfs_ioctl_logical_to_ino+0x158/0x230
   btrfs_ioctl+0x205e/0x4040
   ? __might_sleep+0x71/0xe0
   ? btrfs_ioctl_get_supported_features+0x30/0x30
   ? getrusage+0x4b6/0x9c0
   ? __kasan_check_read+0x11/0x20
   ? lock_release+0xc8/0x620
   ? __might_fault+0x64/0xd0
   ? lock_acquire+0xc7/0x510
   ? lock_downgrade+0x3d0/0x3d0
   ? lockdep_hardirqs_on_prepare+0x210/0x210
   ? lockdep_hardirqs_on_prepare+0x210/0x210
   ? __kasan_check_read+0x11/0x20
   ? do_vfs_ioctl+0xfc/0x9d0
   ? ioctl_file_clone+0xe0/0xe0
   ? lock_downgrade+0x3d0/0x3d0
   ? lockdep_hardirqs_on_prepare+0x210/0x210
   ? __kasan_check_read+0x11/0x20
   ? lock_release+0xc8/0x620
   ? __task_pid_nr_ns+0xd3/0x250
   ? lock_acquire+0xc7/0x510
   ? __fget_files+0x160/0x230
   ? __fget_light+0xf2/0x110
   __x64_sys_ioctl+0xc3/0x100
   do_syscall_64+0x37/0x80
   entry_SYSCALL_64_after_hwframe+0x44/0xa9
  RIP: 0033:0x7fd1976e2427
  Code: 00 00 90 48 8b 05 (...)
  RSP: 002b:00007fd1955e5cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  RAX: ffffffffffffffda RBX: 00007fd1955e5f40 RCX: 00007fd1976e2427
  RDX: 00007fd1955e5f48 RSI: 00000000c038943b RDI: 0000000000000004
  RBP: 0000000001000000 R08: 0000000000000000 R09: 00007fd1955e6120
  R10: 0000557835366b00 R11: 0000000000000246 R12: 0000000000000004
  R13: 00007fd1955e5f48 R14: 00007fd1955e5f40 R15: 00007fd1955e5ef8
  Modules linked in:
  ---[ end trace ec8931a1c36e57be ]---

  (gdb) l *(__tree_mod_log_rewind+0x3b1)
  0xffffffff81893521 is in __tree_mod_log_rewind (fs/btrfs/ctree.c:1210).
  1205                     * the modification. as we're going backwards, we do the
  1206                     * opposite of each operation here.
  1207                     */
  1208                    switch (tm->op) {
  1209                    case MOD_LOG_KEY_REMOVE_WHILE_FREEING:
  1210                            BUG_ON(tm->slot < n);
  1211                            fallthrough;
  1212                    case MOD_LOG_KEY_REMOVE_WHILE_MOVING:
  1213                    case MOD_LOG_KEY_REMOVE:
  1214                            btrfs_set_node_key(eb, &tm->key, tm->slot);

Here's what happens to hit that BUG_ON():

1) We have one tree mod log user (through fiemap or the logical ino ioctl),
   with a sequence number of 1, so we have fs_info->tree_mod_seq == 1;

2) Another task is at ctree.c:balance_level() and we have eb X currently as
   the root of the tree, and we promote its single child, eb Y, as the new
   root.

   Then, at ctree.c:balance_level(), we call:

      tree_mod_log_insert_root(eb X, eb Y, 1);

3) At tree_mod_log_insert_root() we create tree mod log elements for each
   slot of eb X, of operation type MOD_LOG_KEY_REMOVE_WHILE_FREEING each
   with a ->logical pointing to ebX->start. These are placed in an array
   named tm_list.
   Lets assume there are N elements (N pointers in eb X);

4) Then, still at tree_mod_log_insert_root(), we create a tree mod log
   element of operation type MOD_LOG_ROOT_REPLACE, ->logical set to
   ebY->start, ->old_root.logical set to ebX->start, ->old_root.level set
   to the level of eb X and ->generation set to the generation of eb X;

5) Then tree_mod_log_insert_root() calls tree_mod_log_free_eb() with
   tm_list as argument. After that, tree_mod_log_free_eb() calls
   __tree_mod_log_insert() for each member of tm_list in reverse order,
   from highest slot in eb X, slot N - 1, to slot 0 of eb X;

6) __tree_mod_log_insert() sets the sequence number of each given tree mod
   log operation - it increments fs_info->tree_mod_seq and sets
   fs_info->tree_mod_seq as the sequence number of the given tree mod log
   operation.

   This means that for the tm_list created at tree_mod_log_insert_root(),
   the element corresponding to slot 0 of eb X has the highest sequence
   number (1 + N), and the element corresponding to the last slot has the
   lowest sequence number (2);

7) Then, after inserting tm_list's elements into the tree mod log rbtree,
   the MOD_LOG_ROOT_REPLACE element is inserted, which gets the highest
   sequence number, which is N + 2;

8) Back to ctree.c:balance_level(), we free eb X by calling
   btrfs_free_tree_block() on it. Because eb X was created in the current
   transaction, has no other references and writeback did not happen for
   it, we add it back to the free space cache/tree;

9) Later some other task T allocates the metadata extent from eb X, since
   it is marked as free space in the space cache/tree, and uses it as a
   node for some other btree;

10) The tree mod log user task calls btrfs_search_old_slot(), which calls
    get_old_root(), and finally that calls __tree_mod_log_oldest_root()
    with time_seq == 1 and eb_root == eb Y;

11) First iteration of the while loop finds the tree mod log element with
    sequence number N + 2, for the logical address of eb Y and of type
    MOD_LOG_ROOT_REPLACE;

12) Because the operation type is MOD_LOG_ROOT_REPLACE, we don't break out
    of the loop, and set root_logical to point to tm->old_root.logical
    which corresponds to the logical address of eb X;

13) On the next iteration of the while loop, the call to
    tree_mod_log_search_oldest() returns the smallest tree mod log element
    for the logical address of eb X, which has a sequence number of 2, an
    operation type of MOD_LOG_KEY_REMOVE_WHILE_FREEING and corresponds to
    the old slot N - 1 of eb X (eb X had N items in it before being freed);

14) We then break out of the while loop and return the tree mod log operation
    of type MOD_LOG_ROOT_REPLACE (eb Y), and not the one for slot N - 1 of
    eb X, to get_old_root();

15) At get_old_root(), we process the MOD_LOG_ROOT_REPLACE operation
    and set "logical" to the logical address of eb X, which was the old
    root. We then call tree_mod_log_search() passing it the logical
    address of eb X and time_seq == 1;

16) Then before calling tree_mod_log_search(), task T adds a key to eb X,
    which results in adding a tree mod log operation of type
    MOD_LOG_KEY_ADD to the tree mod log - this is done at
    ctree.c:insert_ptr() - but after adding the tree mod log operation
    and before updating the number of items in eb X from 0 to 1...

17) The task at get_old_root() calls tree_mod_log_search() and gets the
    tree mod log operation of type MOD_LOG_KEY_ADD just added by task T.
    Then it enters the following if branch:

    if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) {
       (...)
    } (...)

    Calls read_tree_block() for eb X, which gets a reference on eb X but
    does not lock it - task T has it locked.
    Then it clones eb X while it has nritems set to 0 in its header, before
    task T sets nritems to 1 in eb X's header. From hereupon we use the
    clone of eb X which no other task has access to;

18) Then we call __tree_mod_log_rewind(), passing it the MOD_LOG_KEY_ADD
    mod log operation we just got from tree_mod_log_search() in the
    previous step and the cloned version of eb X;

19) At __tree_mod_log_rewind(), we set the local variable "n" to the number
    of items set in eb X's clone, which is 0. Then we enter the while loop,
    and in its first iteration we process the MOD_LOG_KEY_ADD operation,
    which just decrements "n" from 0 to (u32)-1, since "n" is declared with
    a type of u32. At the end of this iteration we call rb_next() to find the
    next tree mod log operation for eb X, that gives us the mod log operation
    of type MOD_LOG_KEY_REMOVE_WHILE_FREEING, for slot 0, with a sequence
    number of N + 1 (steps 3 to 6);

20) Then we go back to the top of the while loop and trigger the following
    BUG_ON():

        (...)
        switch (tm->op) {
        case MOD_LOG_KEY_REMOVE_WHILE_FREEING:
                 BUG_ON(tm->slot < n);
                 fallthrough;
        (...)

    Because "n" has a value of (u32)-1 (4294967295) and tm->slot is 0.

Fix this by taking a read lock on the extent buffer before cloning it at
ctree.c:get_old_root(). This should be done regardless of the extent
buffer having been freed and reused, as a concurrent task might be
modifying it (while holding a write lock on it).

Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Link: https://lore.kernel.org/linux-btrfs/20210227155037.GN28049@hungrycats.org/
Fixes: 834328a8493079 ("Btrfs: tree mod log's old roots could still be part of the tree")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:06 +01:00
Chao Yu
78486cf1f3 zonefs: fix to update .i_wr_refcnt correctly in zonefs_open_zone()
commit 6980d29ce4da223ad7f0751c7f1d61d3c6b54ab3 upstream.

In zonefs_open_zone(), if opened zone count is larger than
.s_max_open_zones threshold, we missed to recover .i_wr_refcnt,
fix this.

Fixes: b5c00e975779 ("zonefs: open/close zone on file open/close")
Cc: <stable@vger.kernel.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:05 +01:00
Damien Le Moal
9c1c5e81a0 zonefs: prevent use of seq files as swap file
commit 1601ea068b886da1f8f8d4e18b9403e9e24adef6 upstream.

The sequential write constraint of sequential zone file prevent their
use as swap files. Only allow conventional zone files to be used as swap
files.

Fixes: 8dcc1a9d90c1 ("fs: New zonefs file system")
Cc: <stable@vger.kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:05 +01:00
Damien Le Moal
dfbdbf0f35 zonefs: Fix O_APPEND async write handling
commit ebfd68cd0c1e81267c757332385cb96df30dacce upstream.

zonefs updates the size of a sequential zone file inode only on
completion of direct writes. When executing asynchronous append writes
(with a file open with O_APPEND or using RWF_APPEND), the use of the
current inode size in generic_write_checks() to set an iocb offset thus
leads to unaligned write if an application issues an append write
operation with another write already being executed.

Fix this problem by introducing zonefs_write_checks() as a modified
version of generic_write_checks() using the file inode wp_offset for an
append write iocb offset. Also introduce zonefs_write_check_limits() to
replace generic_write_check_limits() call. This zonefs special helper
makes sure that the maximum file limit used is the maximum size of the
file being accessed.

Since zonefs_write_checks() already truncates the iov_iter, the calls
to iov_iter_truncate() in zonefs_file_dio_write() and
zonefs_file_buffered_write() are removed.

Fixes: 8dcc1a9d90c1 ("fs: New zonefs file system")
Cc: <stable@vger.kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-25 09:04:05 +01:00
J. Bruce Fields
df8596f577 Revert "nfsd4: a client's own opens needn't prevent delegations"
commit 6ee65a773096ab3f39d9b00311ac983be5bdeb7c upstream.

This reverts commit 94415b06eb8aed13481646026dc995f04a3a534a.

That commit claimed to allow a client to get a read delegation when it
was the only writer.  Actually it allowed a client to get a read
delegation when *any* client has a write open!

The main problem is that it's depending on nfs4_clnt_odstate structures
that are actually only maintained for pnfs exports.

This causes clients to miss writes performed by other clients, even when
there have been intervening closes and opens, violating close-to-open
cache consistency.

We can do this a different way, but first we should just revert this.

I've added pynfs 4.1 test DELEG19 to test for this, as I should have
done originally!

Cc: stable@vger.kernel.org
Reported-by: Timo Rothenpieler <timo@rothenpieler.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-20 10:43:44 +01:00
J. Bruce Fields
894ecf0cb5 Revert "nfsd4: remove check_conflicting_opens warning"
commit 4aa5e002034f0701c3335379fd6c22d7f3338cce upstream.

This reverts commit 50747dd5e47b "nfsd4: remove check_conflicting_opens
warning", as a prerequisite for reverting 94415b06eb8a, which has a
serious bug.

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-20 10:43:43 +01:00
Amir Goldstein
d955f13ea2 fuse: fix live lock in fuse_iget()
commit 775c5033a0d164622d9d10dd0f0a5531639ed3ed upstream.

Commit 5d069dbe8aaf ("fuse: fix bad inode") replaced make_bad_inode()
in fuse_iget() with a private implementation fuse_make_bad().

The private implementation fails to remove the bad inode from inode
cache, so the retry loop with iget5_locked() finds the same bad inode
and marks it bad forever.

kmsg snip:

[ ] rcu: INFO: rcu_sched self-detected stall on CPU
...
[ ]  ? bit_wait_io+0x50/0x50
[ ]  ? fuse_init_file_inode+0x70/0x70
[ ]  ? find_inode.isra.32+0x60/0xb0
[ ]  ? fuse_init_file_inode+0x70/0x70
[ ]  ilookup5_nowait+0x65/0x90
[ ]  ? fuse_init_file_inode+0x70/0x70
[ ]  ilookup5.part.36+0x2e/0x80
[ ]  ? fuse_init_file_inode+0x70/0x70
[ ]  ? fuse_inode_eq+0x20/0x20
[ ]  iget5_locked+0x21/0x80
[ ]  ? fuse_inode_eq+0x20/0x20
[ ]  fuse_iget+0x96/0x1b0

Fixes: 5d069dbe8aaf ("fuse: fix bad inode")
Cc: stable@vger.kernel.org # 5.10+
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>
2021-03-20 10:43:43 +01:00
Lior Ribak
5ab9464a2a binfmt_misc: fix possible deadlock in bm_register_write
commit e7850f4d844e0acfac7e570af611d89deade3146 upstream.

There is a deadlock in bm_register_write:

First, in the begining of the function, a lock is taken on the binfmt_misc
root inode with inode_lock(d_inode(root)).

Then, if the user used the MISC_FMT_OPEN_FILE flag, the function will call
open_exec on the user-provided interpreter.

open_exec will call a path lookup, and if the path lookup process includes
the root of binfmt_misc, it will try to take a shared lock on its inode
again, but it is already locked, and the code will get stuck in a deadlock

To reproduce the bug:
$ echo ":iiiii:E::ii::/proc/sys/fs/binfmt_misc/bla:F" > /proc/sys/fs/binfmt_misc/register

backtrace of where the lock occurs (#5):
0  schedule () at ./arch/x86/include/asm/current.h:15
1  0xffffffff81b51237 in rwsem_down_read_slowpath (sem=0xffff888003b202e0, count=<optimized out>, state=state@entry=2) at kernel/locking/rwsem.c:992
2  0xffffffff81b5150a in __down_read_common (state=2, sem=<optimized out>) at kernel/locking/rwsem.c:1213
3  __down_read (sem=<optimized out>) at kernel/locking/rwsem.c:1222
4  down_read (sem=<optimized out>) at kernel/locking/rwsem.c:1355
5  0xffffffff811ee22a in inode_lock_shared (inode=<optimized out>) at ./include/linux/fs.h:783
6  open_last_lookups (op=0xffffc9000022fe34, file=0xffff888004098600, nd=0xffffc9000022fd10) at fs/namei.c:3177
7  path_openat (nd=nd@entry=0xffffc9000022fd10, op=op@entry=0xffffc9000022fe34, flags=flags@entry=65) at fs/namei.c:3366
8  0xffffffff811efe1c in do_filp_open (dfd=<optimized out>, pathname=pathname@entry=0xffff8880031b9000, op=op@entry=0xffffc9000022fe34) at fs/namei.c:3396
9  0xffffffff811e493f in do_open_execat (fd=fd@entry=-100, name=name@entry=0xffff8880031b9000, flags=<optimized out>, flags@entry=0) at fs/exec.c:913
10 0xffffffff811e4a92 in open_exec (name=<optimized out>) at fs/exec.c:948
11 0xffffffff8124aa84 in bm_register_write (file=<optimized out>, buffer=<optimized out>, count=19, ppos=<optimized out>) at fs/binfmt_misc.c:682
12 0xffffffff811decd2 in vfs_write (file=file@entry=0xffff888004098500, buf=buf@entry=0xa758d0 ":iiiii:E::ii::i:CF
", count=count@entry=19, pos=pos@entry=0xffffc9000022ff10) at fs/read_write.c:603
13 0xffffffff811defda in ksys_write (fd=<optimized out>, buf=0xa758d0 ":iiiii:E::ii::i:CF
", count=19) at fs/read_write.c:658
14 0xffffffff81b49813 in do_syscall_64 (nr=<optimized out>, regs=0xffffc9000022ff58) at arch/x86/entry/common.c:46
15 0xffffffff81c0007c in entry_SYSCALL_64 () at arch/x86/entry/entry_64.S:120

To solve the issue, the open_exec call is moved to before the write
lock is taken by bm_register_write

Link: https://lkml.kernel.org/r/20210228224414.95962-1-liorribak@gmail.com
Fixes: 948b701a607f1 ("binfmt_misc: add persistent opened binary handler for containers")
Signed-off-by: Lior Ribak <liorribak@gmail.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:35 +01:00
Daiyue Zhang
109720342e configfs: fix a use-after-free in __configfs_open_file
[ Upstream commit 14fbbc8297728e880070f7b077b3301a8c698ef9 ]

Commit b0841eefd969 ("configfs: provide exclusion between IO and removals")
uses ->frag_dead to mark the fragment state, thus no bothering with extra
refcount on config_item when opening a file. The configfs_get_config_item
was removed in __configfs_open_file, but not with config_item_put. So the
refcount on config_item will lost its balance, causing use-after-free
issues in some occasions like this:

Test:
1. Mount configfs on /config with read-only items:
drwxrwx--- 289 root   root            0 2021-04-01 11:55 /config
drwxr-xr-x   2 root   root            0 2021-04-01 11:54 /config/a
--w--w--w-   1 root   root         4096 2021-04-01 11:53 /config/a/1.txt
......

2. Then run:
for file in /config
do
echo $file
grep -R 'key' $file
done

3. __configfs_open_file will be called in parallel, the first one
got called will do:
if (file->f_mode & FMODE_READ) {
	if (!(inode->i_mode & S_IRUGO))
		goto out_put_module;
			config_item_put(buffer->item);
				kref_put()
					package_details_release()
						kfree()

the other one will run into use-after-free issues like this:
BUG: KASAN: use-after-free in __configfs_open_file+0x1bc/0x3b0
Read of size 8 at addr fffffff155f02480 by task grep/13096
CPU: 0 PID: 13096 Comm: grep VIP: 00 Tainted: G        W       4.14.116-kasan #1
TGID: 13096 Comm: grep
Call trace:
dump_stack+0x118/0x160
kasan_report+0x22c/0x294
__asan_load8+0x80/0x88
__configfs_open_file+0x1bc/0x3b0
configfs_open_file+0x28/0x34
do_dentry_open+0x2cc/0x5c0
vfs_open+0x80/0xe0
path_openat+0xd8c/0x2988
do_filp_open+0x1c4/0x2fc
do_sys_open+0x23c/0x404
SyS_openat+0x38/0x48

Allocated by task 2138:
kasan_kmalloc+0xe0/0x1ac
kmem_cache_alloc_trace+0x334/0x394
packages_make_item+0x4c/0x180
configfs_mkdir+0x358/0x740
vfs_mkdir2+0x1bc/0x2e8
SyS_mkdirat+0x154/0x23c
el0_svc_naked+0x34/0x38

Freed by task 13096:
kasan_slab_free+0xb8/0x194
kfree+0x13c/0x910
package_details_release+0x524/0x56c
kref_put+0xc4/0x104
config_item_put+0x24/0x34
__configfs_open_file+0x35c/0x3b0
configfs_open_file+0x28/0x34
do_dentry_open+0x2cc/0x5c0
vfs_open+0x80/0xe0
path_openat+0xd8c/0x2988
do_filp_open+0x1c4/0x2fc
do_sys_open+0x23c/0x404
SyS_openat+0x38/0x48
el0_svc_naked+0x34/0x38

To fix this issue, remove the config_item_put in
__configfs_open_file to balance the refcount of config_item.

Fixes: b0841eefd969 ("configfs: provide exclusion between IO and removals")
Signed-off-by: Daiyue Zhang <zhangdaiyue1@huawei.com>
Signed-off-by: Yi Chen <chenyi77@huawei.com>
Signed-off-by: Ge Qiu <qiuge@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:34 +01:00
Ondrej Mosnacek
caa86901c8 NFSv4.2: fix return value of _nfs4_get_security_label()
[ Upstream commit 53cb245454df5b13d7063162afd7a785aed6ebf2 ]

An xattr 'get' handler is expected to return the length of the value on
success, yet _nfs4_get_security_label() (and consequently also
nfs4_xattr_get_nfs4_label(), which is used as an xattr handler) returns
just 0 on success.

Fix this by returning label.len instead, which contains the length of
the result.

Fixes: aa9c2669626c ("NFS: Client implementation of Labeled-NFS")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:33 +01:00
Trond Myklebust
e181960ec5 NFS: Don't gratuitously clear the inode cache when lookup failed
[ Upstream commit 47397915ede0192235474b145ebcd81b37b03624 ]

The fact that the lookup revalidation failed, does not mean that the
inode contents have changed.

Fixes: 5ceb9d7fdaaf ("NFS: Refactor nfs_lookup_revalidate()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:33 +01:00
Trond Myklebust
dd756d05be NFS: Don't revalidate the directory permissions on a lookup failure
[ Upstream commit 82e7ca1334ab16e2e04fafded1cab9dfcdc11b40 ]

There should be no reason to expect the directory permissions to change
just because the directory contents changed or a negative lookup timed
out. So let's avoid doing a full call to nfs_mark_for_revalidate() in
that case.
Furthermore, if this is a negative dentry, and we haven't actually done
a new lookup, then we have no reason yet to believe the directory has
changed at all. So let's remove the gratuitous directory inode
invalidation altogether when called from
nfs_lookup_revalidate_negative().

Reported-by: Geert Jansen <gerardu@amazon.com>
Fixes: 5ceb9d7fdaaf ("NFS: Refactor nfs_lookup_revalidate()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:33 +01:00
Paulo Alcantara
d308202c1b cifs: do not send close in compound create+close requests
commit 04ad69c342fc4de5bd23be9ef15ea7574fb1a87e upstream.

In case of interrupted syscalls, prevent sending CLOSE commands for
compound CREATE+CLOSE requests by introducing an
CIFS_CP_CREATE_CLOSE_OP flag to indicate lower layers that it should
not send a CLOSE command to the MIDs corresponding the compound
CREATE+CLOSE request.

A simple reproducer:

    #!/bin/bash

    mount //server/share /mnt -o username=foo,password=***
    tc qdisc add dev eth0 root netem delay 450ms
    stat -f /mnt &>/dev/null & pid=$!
    sleep 0.01
    kill $pid
    tc qdisc del dev eth0 root
    umount /mnt

Before patch:

    ...
    6 0.256893470 192.168.122.2 → 192.168.122.15 SMB2 402 Create Request File: ;GetInfo Request FS_INFO/FileFsFullSizeInformation;Close Request
    7 0.257144491 192.168.122.15 → 192.168.122.2 SMB2 498 Create Response File: ;GetInfo Response;Close Response
    9 0.260798209 192.168.122.2 → 192.168.122.15 SMB2 146 Close Request File:
   10 0.260841089 192.168.122.15 → 192.168.122.2 SMB2 130 Close Response, Error: STATUS_FILE_CLOSED

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:28 +01:00
Jan Kara
d44c9780ed block: Try to handle busy underlying device on discard
commit 56887cffe946bb0a90c74429fa94d6110a73119d upstream.

Commit 384d87ef2c95 ("block: Do not discard buffers under a mounted
filesystem") made paths issuing discard or zeroout requests to the
underlying device try to grab block device in exclusive mode. If that
failed we returned EBUSY to userspace. This however caused unexpected
fallout in userspace where e.g. FUSE filesystems issue discard requests
from userspace daemons although the device is open exclusively by the
kernel. Also shrinking of logical volume by LVM issues discard requests
to a device which may be claimed exclusively because there's another LV
on the same PV. So to avoid these userspace regressions, fall back to
invalidate_inode_pages2_range() instead of returning EBUSY to userspace
and return EBUSY only of that call fails as well (meaning that there's
indeed someone using the particular device range we are trying to
discard).

Link: https://bugzilla.kernel.org/show_bug.cgi?id=211167
Fixes: 384d87ef2c95 ("block: Do not discard buffers under a mounted filesystem")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:27 +01:00
Theodore Ts'o
64578f9417 ext4: don't try to processed freed blocks until mballoc is initialized
[ Upstream commit 027f14f5357279655c3ebc6d14daff8368d4f53f ]

If we try to make any changes via the journal between when the journal
is initialized, but before the multi-block allocated is initialized,
we will end up deferencing a NULL pointer when the journal commit
callback function calls ext4_process_freed_data().

The proximate cause of this failure was commit 2d01ddc86606 ("ext4:
save error info to sb through journal if available") since file system
corruption problems detected before the call to ext4_mb_init() would
result in a journal commit before we aborted the mount of the file
system.... and we would then trigger the NULL pointer deref.

Link: https://lore.kernel.org/r/YAm8qH/0oo2ofSMR@mit.edu
Reported-by: Murphy Zhou <jencce.kernel@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:25 +01:00
Steven J. Magnani
82d6c12899 udf: fix silent AED tagLocation corruption
[ Upstream commit 63c9e47a1642fc817654a1bc18a6ec4bbcc0f056 ]

When extending a file, udf_do_extend_file() may enter following empty
indirect extent. At the end of udf_do_extend_file() we revert prev_epos
to point to the last written extent. However if we end up not adding any
further extent in udf_do_extend_file(), the reverting points prev_epos
into the header area of the AED and following updates of the extents
(in udf_update_extents()) will corrupt the header.

Make sure that we do not follow indirect extent if we are not going to
add any more extents so that returning back to the last written extent
works correctly.

Link: https://lore.kernel.org/r/20210107234116.6190-2-magnani@ieee.org
Signed-off-by: Steven J. Magnani <magnani@ieee.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-03-17 17:06:23 +01:00
Aurelien Aptel
3370a84d78 cifs: fix credit accounting for extra channel
commit a249cc8bc2e2fed680047d326eb9a50756724198 upstream.

With multichannel, operations like the queries
from "ls -lR" can cause all credits to be used and
errors to be returned since max_credits was not
being set correctly on the secondary channels and
thus the client was requesting 0 credits incorrectly
in some cases (which can lead to not having
enough credits to perform any operation on that
channel).

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
CC: <stable@vger.kernel.org> # v5.8+
Reviewed-by: Shyam Prasad N <sprasad@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:20 +01:00
Paulo Alcantara
3d0bbd97eb cifs: return proper error code in statfs(2)
commit 14302ee3301b3a77b331cc14efb95bf7184c73cc upstream.

In cifs_statfs(), if server->ops->queryfs is not NULL, then we should
use its return value rather than always returning 0.  Instead, use rc
variable as it is properly set to 0 in case there is no
server->ops->queryfs.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:13 +01:00
Christian Brauner
36e1efcdc5 mount: fix mounting of detached mounts onto targets that reside on shared mounts
commit ee2e3f50629f17b0752b55b2566c15ce8dafb557 upstream.

Creating a series of detached mounts, attaching them to the filesystem,
and unmounting them can be used to trigger an integer overflow in
ns->mounts causing the kernel to block any new mounts in count_mounts()
and returning ENOSPC because it falsely assumes that the maximum number
of mounts in the mount namespace has been reached, i.e. it thinks it
can't fit the new mounts into the mount namespace anymore.

Depending on the number of mounts in your system, this can be reproduced
on any kernel that supportes open_tree() and move_mount() by compiling
and running the following program:

  /* SPDX-License-Identifier: LGPL-2.1+ */

  #define _GNU_SOURCE
  #include <errno.h>
  #include <fcntl.h>
  #include <getopt.h>
  #include <limits.h>
  #include <stdbool.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <sys/mount.h>
  #include <sys/stat.h>
  #include <sys/syscall.h>
  #include <sys/types.h>
  #include <unistd.h>

  /* open_tree() */
  #ifndef OPEN_TREE_CLONE
  #define OPEN_TREE_CLONE 1
  #endif

  #ifndef OPEN_TREE_CLOEXEC
  #define OPEN_TREE_CLOEXEC O_CLOEXEC
  #endif

  #ifndef __NR_open_tree
          #if defined __alpha__
                  #define __NR_open_tree 538
          #elif defined _MIPS_SIM
                  #if _MIPS_SIM == _MIPS_SIM_ABI32        /* o32 */
                          #define __NR_open_tree 4428
                  #endif
                  #if _MIPS_SIM == _MIPS_SIM_NABI32       /* n32 */
                          #define __NR_open_tree 6428
                  #endif
                  #if _MIPS_SIM == _MIPS_SIM_ABI64        /* n64 */
                          #define __NR_open_tree 5428
                  #endif
          #elif defined __ia64__
                  #define __NR_open_tree (428 + 1024)
          #else
                  #define __NR_open_tree 428
          #endif
  #endif

  /* move_mount() */
  #ifndef MOVE_MOUNT_F_EMPTY_PATH
  #define MOVE_MOUNT_F_EMPTY_PATH 0x00000004 /* Empty from path permitted */
  #endif

  #ifndef __NR_move_mount
          #if defined __alpha__
                  #define __NR_move_mount 539
          #elif defined _MIPS_SIM
                  #if _MIPS_SIM == _MIPS_SIM_ABI32        /* o32 */
                          #define __NR_move_mount 4429
                  #endif
                  #if _MIPS_SIM == _MIPS_SIM_NABI32       /* n32 */
                          #define __NR_move_mount 6429
                  #endif
                  #if _MIPS_SIM == _MIPS_SIM_ABI64        /* n64 */
                          #define __NR_move_mount 5429
                  #endif
          #elif defined __ia64__
                  #define __NR_move_mount (428 + 1024)
          #else
                  #define __NR_move_mount 429
          #endif
  #endif

  static inline int sys_open_tree(int dfd, const char *filename, unsigned int flags)
  {
          return syscall(__NR_open_tree, dfd, filename, flags);
  }

  static inline int sys_move_mount(int from_dfd, const char *from_pathname, int to_dfd,
                                   const char *to_pathname, unsigned int flags)
  {
          return syscall(__NR_move_mount, from_dfd, from_pathname, to_dfd, to_pathname, flags);
  }

  static bool is_shared_mountpoint(const char *path)
  {
          bool shared = false;
          FILE *f = NULL;
          char *line = NULL;
          int i;
          size_t len = 0;

          f = fopen("/proc/self/mountinfo", "re");
          if (!f)
                  return 0;

          while (getline(&line, &len, f) > 0) {
                  char *slider1, *slider2;

                  for (slider1 = line, i = 0; slider1 && i < 4; i++)
                          slider1 = strchr(slider1 + 1, ' ');

                  if (!slider1)
                          continue;

                  slider2 = strchr(slider1 + 1, ' ');
                  if (!slider2)
                          continue;

                  *slider2 = '\0';
                  if (strcmp(slider1 + 1, path) == 0) {
                          /* This is the path. Is it shared? */
                          slider1 = strchr(slider2 + 1, ' ');
                          if (slider1 && strstr(slider1, "shared:")) {
                                  shared = true;
                                  break;
                          }
                  }
          }
          fclose(f);
          free(line);

          return shared;
  }

  static void usage(void)
  {
          const char *text = "mount-new [--recursive] <base-dir>\n";
          fprintf(stderr, "%s", text);
          _exit(EXIT_SUCCESS);
  }

  #define exit_usage(format, ...)                              \
          ({                                                   \
                  fprintf(stderr, format "\n", ##__VA_ARGS__); \
                  usage();                                     \
          })

  #define exit_log(format, ...)                                \
          ({                                                   \
                  fprintf(stderr, format "\n", ##__VA_ARGS__); \
                  exit(EXIT_FAILURE);                          \
          })

  static const struct option longopts[] = {
          {"help",        no_argument,            0,      'a'},
          { NULL,         no_argument,            0,       0 },
  };

  int main(int argc, char *argv[])
  {
          int exit_code = EXIT_SUCCESS, index = 0;
          int dfd, fd_tree, new_argc, ret;
          char *base_dir;
          char *const *new_argv;
          char target[PATH_MAX];

          while ((ret = getopt_long_only(argc, argv, "", longopts, &index)) != -1) {
                  switch (ret) {
                  case 'a':
                          /* fallthrough */
                  default:
                          usage();
                  }
          }

          new_argv = &argv[optind];
          new_argc = argc - optind;
          if (new_argc < 1)
                  exit_usage("Missing base directory\n");
          base_dir = new_argv[0];

          if (*base_dir != '/')
                  exit_log("Please specify an absolute path");

          /* Ensure that target is a shared mountpoint. */
          if (!is_shared_mountpoint(base_dir))
                  exit_log("Please ensure that \"%s\" is a shared mountpoint", base_dir);

          dfd = open(base_dir, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
          if (dfd < 0)
                  exit_log("%m - Failed to open base directory \"%s\"", base_dir);

          ret = mkdirat(dfd, "detached-move-mount", 0755);
          if (ret < 0)
                  exit_log("%m - Failed to create required temporary directories");

          ret = snprintf(target, sizeof(target), "%s/detached-move-mount", base_dir);
          if (ret < 0 || (size_t)ret >= sizeof(target))
                  exit_log("%m - Failed to assemble target path");

          /*
           * Having a mount table with 10000 mounts is already quite excessive
           * and shoult account even for weird test systems.
           */
          for (size_t i = 0; i < 10000; i++) {
                  fd_tree = sys_open_tree(dfd, "detached-move-mount",
                                          OPEN_TREE_CLONE |
                                          OPEN_TREE_CLOEXEC |
                                          AT_EMPTY_PATH);
                  if (fd_tree < 0) {
                          fprintf(stderr, "%m - Failed to open %d(detached-move-mount)", dfd);
                          exit_code = EXIT_FAILURE;
                          break;
                  }

                  ret = sys_move_mount(fd_tree, "", dfd, "detached-move-mount", MOVE_MOUNT_F_EMPTY_PATH);
                  if (ret < 0) {
                          if (errno == ENOSPC)
                                  fprintf(stderr, "%m - Buggy mount counting");
                          else
                                  fprintf(stderr, "%m - Failed to attach mount to %d(detached-move-mount)", dfd);
                          exit_code = EXIT_FAILURE;
                          break;
                  }
                  close(fd_tree);

                  ret = umount2(target, MNT_DETACH);
                  if (ret < 0) {
                          fprintf(stderr, "%m - Failed to unmount %s", target);
                          exit_code = EXIT_FAILURE;
                          break;
                  }
          }

          (void)unlinkat(dfd, "detached-move-mount", AT_REMOVEDIR);
          close(dfd);

          exit(exit_code);
  }

and wait for the kernel to refuse any new mounts by returning ENOSPC.
How many iterations are needed depends on the number of mounts in your
system. Assuming you have something like 50 mounts on a standard system
it should be almost instantaneous.

The root cause of this is that detached mounts aren't handled correctly
when source and target mount are identical and reside on a shared mount
causing a broken mount tree where the detached source itself is
propagated which propagation prevents for regular bind-mounts and new
mounts. This ultimately leads to a miscalculation of the number of
mounts in the mount namespace.

Detached mounts created via
open_tree(fd, path, OPEN_TREE_CLONE)
are essentially like an unattached new mount, or an unattached
bind-mount. They can then later on be attached to the filesystem via
move_mount() which calls into attach_recursive_mount(). Part of
attaching it to the filesystem is making sure that mounts get correctly
propagated in case the destination mountpoint is MS_SHARED, i.e. is a
shared mountpoint. This is done by calling into propagate_mnt() which
walks the list of peers calling propagate_one() on each mount in this
list making sure it receives the propagation event.
The propagate_one() functions thereby skips both new mounts and bind
mounts to not propagate them "into themselves". Both are identified by
checking whether the mount is already attached to any mount namespace in
mnt->mnt_ns. The is what the IS_MNT_NEW() helper is responsible for.

However, detached mounts have an anonymous mount namespace attached to
them stashed in mnt->mnt_ns which means that IS_MNT_NEW() doesn't
realize they need to be skipped causing the mount to propagate "into
itself" breaking the mount table and causing a disconnect between the
number of mounts recorded as being beneath or reachable from the target
mountpoint and the number of mounts actually recorded/counted in
ns->mounts ultimately causing an overflow which in turn prevents any new
mounts via the ENOSPC issue.

So teach propagation to handle detached mounts by making it aware of
them. I've been tracking this issue down for the last couple of days and
then verifying that the fix is correct by
unmounting everything in my current mount table leaving only /proc and
/sys mounted and running the reproducer above overnight verifying the
number of mounts counted in ns->mounts. With this fix the counts are
correct and the ENOSPC issue can't be reproduced.

This change will only have an effect on mounts created with the new
mount API since detached mounts cannot be created with the old mount API
so regressions are extremely unlikely.

Link: https://lore.kernel.org/r/20210306101010.243666-1-christian.brauner@ubuntu.com
Fixes: 2db154b3ea8e ("vfs: syscall: Add move_mount(2) to move mounts around")
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Cc: <stable@vger.kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-17 17:06:13 +01:00
Nikolay Borisov
bf6dd437c3 btrfs: don't flush from btrfs_delayed_inode_reserve_metadata
commit 4d14c5cde5c268a2bc26addecf09489cb953ef64 upstream

Calling btrfs_qgroup_reserve_meta_prealloc from
btrfs_delayed_inode_reserve_metadata can result in flushing delalloc
while holding a transaction and delayed node locks. This is deadlock
prone. In the past multiple commits:

 * ae5e070eaca9 ("btrfs: qgroup: don't try to wait flushing if we're
already holding a transaction")

 * 6f23277a49e6 ("btrfs: qgroup: don't commit transaction when we already
 hold the handle")

Tried to solve various aspects of this but this was always a
whack-a-mole game. Unfortunately those 2 fixes don't solve a deadlock
scenario involving btrfs_delayed_node::mutex. Namely, one thread
can call btrfs_dirty_inode as a result of reading a file and modifying
its atime:

  PID: 6963   TASK: ffff8c7f3f94c000  CPU: 2   COMMAND: "test"
  #0  __schedule at ffffffffa529e07d
  #1  schedule at ffffffffa529e4ff
  #2  schedule_timeout at ffffffffa52a1bdd
  #3  wait_for_completion at ffffffffa529eeea             <-- sleeps with delayed node mutex held
  #4  start_delalloc_inodes at ffffffffc0380db5
  #5  btrfs_start_delalloc_snapshot at ffffffffc0393836
  #6  try_flush_qgroup at ffffffffc03f04b2
  #7  __btrfs_qgroup_reserve_meta at ffffffffc03f5bb6     <-- tries to reserve space and starts delalloc inodes.
  #8  btrfs_delayed_update_inode at ffffffffc03e31aa      <-- acquires delayed node mutex
  #9  btrfs_update_inode at ffffffffc0385ba8
 #10  btrfs_dirty_inode at ffffffffc038627b               <-- TRANSACTIION OPENED
 #11  touch_atime at ffffffffa4cf0000
 #12  generic_file_read_iter at ffffffffa4c1f123
 #13  new_sync_read at ffffffffa4ccdc8a
 #14  vfs_read at ffffffffa4cd0849
 #15  ksys_read at ffffffffa4cd0bd1
 #16  do_syscall_64 at ffffffffa4a052eb
 #17  entry_SYSCALL_64_after_hwframe at ffffffffa540008c

This will cause an asynchronous work to flush the delalloc inodes to
happen which can try to acquire the same delayed_node mutex:

  PID: 455    TASK: ffff8c8085fa4000  CPU: 5   COMMAND: "kworker/u16:30"
  #0  __schedule at ffffffffa529e07d
  #1  schedule at ffffffffa529e4ff
  #2  schedule_preempt_disabled at ffffffffa529e80a
  #3  __mutex_lock at ffffffffa529fdcb                    <-- goes to sleep, never wakes up.
  #4  btrfs_delayed_update_inode at ffffffffc03e3143      <-- tries to acquire the mutex
  #5  btrfs_update_inode at ffffffffc0385ba8              <-- this is the same inode that pid 6963 is holding
  #6  cow_file_range_inline.constprop.78 at ffffffffc0386be7
  #7  cow_file_range at ffffffffc03879c1
  #8  btrfs_run_delalloc_range at ffffffffc038894c
  #9  writepage_delalloc at ffffffffc03a3c8f
 #10  __extent_writepage at ffffffffc03a4c01
 #11  extent_write_cache_pages at ffffffffc03a500b
 #12  extent_writepages at ffffffffc03a6de2
 #13  do_writepages at ffffffffa4c277eb
 #14  __filemap_fdatawrite_range at ffffffffa4c1e5bb
 #15  btrfs_run_delalloc_work at ffffffffc0380987         <-- starts running delayed nodes
 #16  normal_work_helper at ffffffffc03b706c
 #17  process_one_work at ffffffffa4aba4e4
 #18  worker_thread at ffffffffa4aba6fd
 #19  kthread at ffffffffa4ac0a3d
 #20  ret_from_fork at ffffffffa54001ff

To fully address those cases the complete fix is to never issue any
flushing while holding the transaction or the delayed node lock. This
patch achieves it by calling qgroup_reserve_meta directly which will
either succeed without flushing or will fail and return -EDQUOT. In the
latter case that return value is going to be propagated to
btrfs_dirty_inode which will fallback to start a new transaction. That's
fine as the majority of time we expect the inode will have
BTRFS_DELAYED_NODE_INODE_DIRTY flag set which will result in directly
copying the in-memory state.

Fixes: c53e9653605d ("btrfs: qgroup: try to flush qgroup space when we get -EDQUOT")
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-11 14:17:22 +01:00
Nikolay Borisov
cf9317ceb5 btrfs: export and rename qgroup_reserve_meta
commit 80e9baed722c853056e0c5374f51524593cb1031 upstream

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-11 14:17:22 +01:00