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  1. 17 9月, 2019 3 次提交
  3. 16 9月, 2019 1 次提交
    • L
      Revert "ext4: make __ext4_get_inode_loc plug" · 72dbcf72
      由 Linus Torvalds 提交于 
      This reverts commit b03755ad.

This is sad, and done for all the wrong reasons.  Because that commit is
good, and does exactly what it says: avoids a lot of small disk requests
for the inode table read-ahead.

However, it turns out that it causes an entirely unrelated problem: the
getrandom() system call was introduced back in 2014 by commit
c6e9d6f3 ("random: introduce getrandom(2) system call"), and people
use it as a convenient source of good random numbers.

But part of the current semantics for getrandom() is that it waits for
the entropy pool to fill at least partially (unlike /dev/urandom).  And
at least ArchLinux apparently has a systemd that uses getrandom() at
boot time, and the improvements in IO patterns means that existing
installations suddenly start hanging, waiting for entropy that will
never happen.

It seems to be an unlucky combination of not _quite_ enough entropy,
together with a particular systemd version and configuration.  Lennart
says that the systemd-random-seed process (which is what does this early
access) is supposed to not block any other boot activity, but sadly that
doesn't actually seem to be the case (possibly due bogus dependencies on
cryptsetup for encrypted swapspace).

The correct fix is to fix getrandom() to not block when it's not
appropriate, but that fix is going to take a lot more discussion.  Do we
just make it act like /dev/urandom by default, and add a new flag for
"wait for entropy"? Do we add a boot-time option? Or do we just limit
the amount of time it will wait for entropy?

So in the meantime, we do the revert to give us time to discuss the
eventual fix for the fundamental problem, at which point we can re-apply
the ext4 inode table access optimization.
Reported-by: NAhmed S. Darwish <darwish.07@gmail.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Alexander E. Patrakov <patrakov@gmail.com>
Cc: Lennart Poettering <mzxreary@0pointer.de>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      72dbcf72
  5. 12 9月, 2019 2 次提交
    • F
      Btrfs: fix unwritten extent buffers and hangs on future writeback attempts · 18dfa711
      由 Filipe Manana 提交于 
      The lock_extent_buffer_io() returns 1 to the caller to tell it everything
went fine and the callers needs to start writeback for the extent buffer
(submit a bio, etc), 0 to tell the caller everything went fine but it does
not need to start writeback for the extent buffer, and a negative value if
some error happened.

When it's about to return 1 it tries to lock all pages, and if a try lock
on a page fails, and we didn't flush any existing bio in our "epd", it
calls flush_write_bio(epd) and overwrites the return value of 1 to 0 or
an error. The page might have been locked elsewhere, not with the goal
of starting writeback of the extent buffer, and even by some code other
than btrfs, like page migration for example, so it does not mean the
writeback of the extent buffer was already started by some other task,
so returning a 0 tells the caller (btree_write_cache_pages()) to not
start writeback for the extent buffer. Note that epd might currently have
either no bio, so flush_write_bio() returns 0 (success) or it might have
a bio for another extent buffer with a lower index (logical address).

Since we return 0 with the EXTENT_BUFFER_WRITEBACK bit set on the
extent buffer and writeback is never started for the extent buffer,
future attempts to writeback the extent buffer will hang forever waiting
on that bit to be cleared, since it can only be cleared after writeback
completes. Such hang is reported with a trace like the following:

  [49887.347053] INFO: task btrfs-transacti:1752 blocked for more than 122 seconds.
  [49887.347059]       Not tainted 5.2.13-gentoo #2
  [49887.347060] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [49887.347062] btrfs-transacti D    0  1752      2 0x80004000
  [49887.347064] Call Trace:
  [49887.347069]  ? __schedule+0x265/0x830
  [49887.347071]  ? bit_wait+0x50/0x50
  [49887.347072]  ? bit_wait+0x50/0x50
  [49887.347074]  schedule+0x24/0x90
  [49887.347075]  io_schedule+0x3c/0x60
  [49887.347077]  bit_wait_io+0x8/0x50
  [49887.347079]  __wait_on_bit+0x6c/0x80
  [49887.347081]  ? __lock_release.isra.29+0x155/0x2d0
  [49887.347083]  out_of_line_wait_on_bit+0x7b/0x80
  [49887.347084]  ? var_wake_function+0x20/0x20
  [49887.347087]  lock_extent_buffer_for_io+0x28c/0x390
  [49887.347089]  btree_write_cache_pages+0x18e/0x340
  [49887.347091]  do_writepages+0x29/0xb0
  [49887.347093]  ? kmem_cache_free+0x132/0x160
  [49887.347095]  ? convert_extent_bit+0x544/0x680
  [49887.347097]  filemap_fdatawrite_range+0x70/0x90
  [49887.347099]  btrfs_write_marked_extents+0x53/0x120
  [49887.347100]  btrfs_write_and_wait_transaction.isra.4+0x38/0xa0
  [49887.347102]  btrfs_commit_transaction+0x6bb/0x990
  [49887.347103]  ? start_transaction+0x33e/0x500
  [49887.347105]  transaction_kthread+0x139/0x15c

So fix this by not overwriting the return value (ret) with the result
from flush_write_bio(). We also need to clear the EXTENT_BUFFER_WRITEBACK
bit in case flush_write_bio() returns an error, otherwise it will hang
any future attempts to writeback the extent buffer, and undo all work
done before (set back EXTENT_BUFFER_DIRTY, etc).

This is a regression introduced in the 5.2 kernel.

Fixes: 2e3c2513 ("btrfs: extent_io: add proper error handling to lock_extent_buffer_for_io()")
Fixes: f4340622 ("btrfs: extent_io: Move the BUG_ON() in flush_write_bio() one level up")
Reported-by: NZdenek Sojka <zsojka@seznam.cz>
Link: https://lore.kernel.org/linux-btrfs/GpO.2yos.3WGDOLpx6t%7D.1TUDYM@seznam.cz/T/#uReported-by: NStefan Priebe - Profihost AG <s.priebe@profihost.ag>
Link: https://lore.kernel.org/linux-btrfs/5c4688ac-10a7-fb07-70e8-c5d31a3fbb38@profihost.ag/T/#tReported-by: NDrazen Kacar <drazen.kacar@oradian.com>
Link: https://lore.kernel.org/linux-btrfs/DB8PR03MB562876ECE2319B3E579590F799C80@DB8PR03MB5628.eurprd03.prod.outlook.com/
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204377Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      18dfa711
    • F
      Btrfs: fix assertion failure during fsync and use of stale transaction · 410f954c
      由 Filipe Manana 提交于 
      Sometimes when fsync'ing a file we need to log that other inodes exist and
when we need to do that we acquire a reference on the inodes and then drop
that reference using iput() after logging them.

That generally is not a problem except if we end up doing the final iput()
(dropping the last reference) on the inode and that inode has a link count
of 0, which can happen in a very short time window if the logging path
gets a reference on the inode while it's being unlinked.

In that case we end up getting the eviction callback, btrfs_evict_inode(),
invoked through the iput() call chain which needs to drop all of the
inode's items from its subvolume btree, and in order to do that, it needs
to join a transaction at the helper function evict_refill_and_join().
However because the task previously started a transaction at the fsync
handler, btrfs_sync_file(), it has current->journal_info already pointing
to a transaction handle and therefore evict_refill_and_join() will get
that transaction handle from btrfs_join_transaction(). From this point on,
two different problems can happen:

1) evict_refill_and_join() will often change the transaction handle's
   block reserve (->block_rsv) and set its ->bytes_reserved field to a
   value greater than 0. If evict_refill_and_join() never commits the
   transaction, the eviction handler ends up decreasing the reference
   count (->use_count) of the transaction handle through the call to
   btrfs_end_transaction(), and after that point we have a transaction
   handle with a NULL ->block_rsv (which is the value prior to the
   transaction join from evict_refill_and_join()) and a ->bytes_reserved
   value greater than 0. If after the eviction/iput completes the inode
   logging path hits an error or it decides that it must fallback to a
   transaction commit, the btrfs fsync handle, btrfs_sync_file(), gets a
   non-zero value from btrfs_log_dentry_safe(), and because of that
   non-zero value it tries to commit the transaction using a handle with
   a NULL ->block_rsv and a non-zero ->bytes_reserved value. This makes
   the transaction commit hit an assertion failure at
   btrfs_trans_release_metadata() because ->bytes_reserved is not zero but
   the ->block_rsv is NULL. The produced stack trace for that is like the
   following:

   [192922.917158] assertion failed: !trans->bytes_reserved, file: fs/btrfs/transaction.c, line: 816
   [192922.917553] ------------[ cut here ]------------
   [192922.917922] kernel BUG at fs/btrfs/ctree.h:3532!
   [192922.918310] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
   [192922.918666] CPU: 2 PID: 883 Comm: fsstress Tainted: G        W         5.1.4-btrfs-next-47 #1
   [192922.919035] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
   [192922.919801] RIP: 0010:assfail.constprop.25+0x18/0x1a [btrfs]
   (...)
   [192922.920925] RSP: 0018:ffffaebdc8a27da8 EFLAGS: 00010286
   [192922.921315] RAX: 0000000000000051 RBX: ffff95c9c16a41c0 RCX: 0000000000000000
   [192922.921692] RDX: 0000000000000000 RSI: ffff95cab6b16838 RDI: ffff95cab6b16838
   [192922.922066] RBP: ffff95c9c16a41c0 R08: 0000000000000000 R09: 0000000000000000
   [192922.922442] R10: ffffaebdc8a27e70 R11: 0000000000000000 R12: ffff95ca731a0980
   [192922.922820] R13: 0000000000000000 R14: ffff95ca84c73338 R15: ffff95ca731a0ea8
   [192922.923200] FS:  00007f337eda4e80(0000) GS:ffff95cab6b00000(0000) knlGS:0000000000000000
   [192922.923579] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   [192922.923948] CR2: 00007f337edad000 CR3: 00000001e00f6002 CR4: 00000000003606e0
   [192922.924329] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
   [192922.924711] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
   [192922.925105] Call Trace:
   [192922.925505]  btrfs_trans_release_metadata+0x10c/0x170 [btrfs]
   [192922.925911]  btrfs_commit_transaction+0x3e/0xaf0 [btrfs]
   [192922.926324]  btrfs_sync_file+0x44c/0x490 [btrfs]
   [192922.926731]  do_fsync+0x38/0x60
   [192922.927138]  __x64_sys_fdatasync+0x13/0x20
   [192922.927543]  do_syscall_64+0x60/0x1c0
   [192922.927939]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
   (...)
   [192922.934077] ---[ end trace f00808b12068168f ]---

2) If evict_refill_and_join() decides to commit the transaction, it will
   be able to do it, since the nested transaction join only increments the
   transaction handle's ->use_count reference counter and it does not
   prevent the transaction from getting committed. This means that after
   eviction completes, the fsync logging path will be using a transaction
   handle that refers to an already committed transaction. What happens
   when using such a stale transaction can be unpredictable, we are at
   least having a use-after-free on the transaction handle itself, since
   the transaction commit will call kmem_cache_free() against the handle
   regardless of its ->use_count value, or we can end up silently losing
   all the updates to the log tree after that iput() in the logging path,
   or using a transaction handle that in the meanwhile was allocated to
   another task for a new transaction, etc, pretty much unpredictable
   what can happen.

In order to fix both of them, instead of using iput() during logging, use
btrfs_add_delayed_iput(), so that the logging path of fsync never drops
the last reference on an inode, that step is offloaded to a safe context
(usually the cleaner kthread).

The assertion failure issue was sporadically triggered by the test case
generic/475 from fstests, which loads the dm error target while fsstress
is running, which lead to fsync failing while logging inodes with -EIO
errors and then trying later to commit the transaction, triggering the
assertion failure.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Signed-off-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>
      410f954c
  7. 05 9月, 2019 1 次提交
    • A
      configfs: provide exclusion between IO and removals · b0841eef
      由 Al Viro 提交于 
      Make sure that attribute methods are not called after the item
has been removed from the tree.  To do so, we
	* at the point of no return in removals, grab ->frag_sem
exclusive and mark the fragment dead.
	* call the methods of attributes with ->frag_sem taken
shared and only after having verified that the fragment is still
alive.

	The main benefit is for method instances - they are
guaranteed that the objects they are accessing *and* all ancestors
are still there.  Another win is that we don't need to bother
with extra refcount on config_item when opening a file -
the item will be alive for as long as it stays in the tree, and
we won't touch it/attributes/any associated data after it's
been removed from the tree.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
      b0841eef
  9. 03 9月, 2019 4 次提交
  11. 28 8月, 2019 4 次提交
  13. 27 8月, 2019 8 次提交
  15. 25 8月, 2019 1 次提交
  17. 23 8月, 2019 2 次提交
    • D
      xfs: fix missing ILOCK unlock when xfs_setattr_nonsize fails due to EDQUOT · 1fb254aa
      由 Darrick J. Wong 提交于 
      Benjamin Moody reported to Debian that XFS partially wedges when a chgrp
fails on account of being out of disk quota.  I ran his reproducer
script:

# adduser dummy
# adduser dummy plugdev

# dd if=/dev/zero bs=1M count=100 of=test.img
# mkfs.xfs test.img
# mount -t xfs -o gquota test.img /mnt
# mkdir -p /mnt/dummy
# chown -c dummy /mnt/dummy
# xfs_quota -xc 'limit -g bsoft=100k bhard=100k plugdev' /mnt

(and then as user dummy)

$ dd if=/dev/urandom bs=1M count=50 of=/mnt/dummy/foo
$ chgrp plugdev /mnt/dummy/foo

and saw:

================================================
WARNING: lock held when returning to user space!
5.3.0-rc5 #rc5 Tainted: G        W
------------------------------------------------
chgrp/47006 is leaving the kernel with locks still held!
1 lock held by chgrp/47006:
 #0: 000000006664ea2d (&xfs_nondir_ilock_class){++++}, at: xfs_ilock+0xd2/0x290 [xfs]

...which is clearly caused by xfs_setattr_nonsize failing to unlock the
ILOCK after the xfs_qm_vop_chown_reserve call fails.  Add the missing
unlock.

Reported-by: benjamin.moody@gmail.com
Fixes: 253f4911 ("xfs: better xfs_trans_alloc interface")
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Tested-by: NSalvatore Bonaccorso <carnil@debian.org>
      1fb254aa
    • J
      io_uring: add need_resched() check in inner poll loop · 08f5439f
      由 Jens Axboe 提交于 
      The outer poll loop checks for whether we need to reschedule, and
returns to userspace if we do. However, it's possible to get stuck
in the inner loop as well, if the CPU we are running on needs to
reschedule to finish the IO work.

Add the need_resched() check in the inner loop as well. This fixes
a potential hang if the kernel is configured with
CONFIG_PREEMPT_VOLUNTARY=y.
Reported-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Tested-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      08f5439f
  19. 22 8月, 2019 11 次提交
    • L
      ubifs: Limit the number of pages in shrink_liability · 0af83abb
      由 Liu Song 提交于 
      If the number of dirty pages to be written back is large,
then writeback_inodes_sb will block waiting for a long time,
causing hung task detection alarm. Therefore, we should limit
the maximum number of pages written back this time, which let
the budget be completed faster. The remaining dirty pages
tend to rely on the writeback mechanism to complete the
synchronization.

Fixes: b6e51316 ("writeback: separate starting of sync vs opportunistic writeback")
Signed-off-by: NLiu Song <liu.song11@zte.com.cn>
Signed-off-by: NRichard Weinberger <richard@nod.at>
      0af83abb
    • R
      ubifs: Correctly initialize c->min_log_bytes · 377e208f
      由 Richard Weinberger 提交于 
      Currently on a freshly mounted UBIFS, c->min_log_bytes is 0.
This can lead to a log overrun and make commits fail.

Recent kernels will report the following assert:
UBIFS assert failed: c->lhead_lnum != c->ltail_lnum, in fs/ubifs/log.c:412

c->min_log_bytes can have two states, 0 and c->leb_size.
It controls how much bytes of the log area are reserved for non-bud
nodes such as commit nodes.

After a commit it has to be set to c->leb_size such that we have always
enough space for a commit. While a commit runs it can be 0 to make the
remaining bytes of the log available to writers.

Having it set to 0 right after mount is wrong since no space for commits
is reserved.

Fixes: 1e51764a ("UBIFS: add new flash file system")
Reported-and-tested-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NRichard Weinberger <richard@nod.at>
      377e208f
    • R
      ubifs: Fix double unlock around orphan_delete() · 4dd75b33
      由 Richard Weinberger 提交于 
      We unlock after orphan_delete(), so no need to unlock
in the function too.
Reported-by: NHan Xu <han.xu@nxp.com>
Fixes: 8009ce95 ("ubifs: Don't leak orphans on memory during commit")
Signed-off-by: NRichard Weinberger <richard@nod.at>
      4dd75b33
    • Y
      afs: use correct afs_call_type in yfs_fs_store_opaque_acl2 · 7533be85
      由 YueHaibing 提交于 
      It seems that 'yfs_RXYFSStoreOpaqueACL2' should be use in
yfs_fs_store_opaque_acl2().

Fixes: f5e45463 ("afs: Implement YFS ACL setting")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
      7533be85
    • M
      afs: Fix possible oops in afs_lookup trace event · c4c613ff
      由 Marc Dionne 提交于 
      The afs_lookup trace event can cause the following:

[  216.576777] BUG: kernel NULL pointer dereference, address: 000000000000023b
[  216.576803] #PF: supervisor read access in kernel mode
[  216.576813] #PF: error_code(0x0000) - not-present page
...
[  216.576913] RIP: 0010:trace_event_raw_event_afs_lookup+0x9e/0x1c0 [kafs]

If the inode from afs_do_lookup() is an error other than ENOENT, or if it
is ENOENT and afs_try_auto_mntpt() returns an error, the trace event will
try to dereference the error pointer as a valid pointer.

Use IS_ERR_OR_NULL to only pass a valid pointer for the trace, or NULL.

Ideally the trace would include the error value, but for now just avoid
the oops.

Fixes: 80548b03 ("afs: Add more tracepoints")
Signed-off-by: NMarc Dionne <marc.dionne@auristor.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
      c4c613ff
    • D
      afs: Fix leak in afs_lookup_cell_rcu() · a5fb8e6c
      由 David Howells 提交于 
      Fix a leak on the cell refcount in afs_lookup_cell_rcu() due to
non-clearance of the default error in the case a NULL cell name is passed
and the workstation default cell is used.

Also put a bit at the end to make sure we don't leak a cell ref if we're
going to be returning an error.

This leak results in an assertion like the following when the kafs module is
unloaded:

	AFS: Assertion failed
	2 == 1 is false
	0x2 == 0x1 is false
	------------[ cut here ]------------
	kernel BUG at fs/afs/cell.c:770!
	...
	RIP: 0010:afs_manage_cells+0x220/0x42f [kafs]
	...
	 process_one_work+0x4c2/0x82c
	 ? pool_mayday_timeout+0x1e1/0x1e1
	 ? do_raw_spin_lock+0x134/0x175
	 worker_thread+0x336/0x4a6
	 ? rescuer_thread+0x4af/0x4af
	 kthread+0x1de/0x1ee
	 ? kthread_park+0xd4/0xd4
	 ret_from_fork+0x24/0x30

Fixes: 989782dc ("afs: Overhaul cell database management")
Signed-off-by: NDavid Howells <dhowells@redhat.com>
      a5fb8e6c
    • J
      ceph: don't try fill file_lock on unsuccessful GETFILELOCK reply · 28a28261
      由 Jeff Layton 提交于 
      When ceph_mdsc_do_request returns an error, we can't assume that the
filelock_reply pointer will be set. Only try to fetch fields out of
the r_reply_info when it returns success.

Cc: stable@vger.kernel.org
Reported-by: NHector Martin <hector@marcansoft.com>
Signed-off-by: NJeff Layton <jlayton@kernel.org>
Reviewed-by: N"Yan, Zheng" <zyan@redhat.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
      28a28261
    • E
      ceph: clear page dirty before invalidate page · c95f1c5f
      由 Erqi Chen 提交于 
      clear_page_dirty_for_io(page) before mapping->a_ops->invalidatepage().
invalidatepage() clears page's private flag, if dirty flag is not
cleared, the page may cause BUG_ON failure in ceph_set_page_dirty().

Cc: stable@vger.kernel.org
Link: https://tracker.ceph.com/issues/40862Signed-off-by: NErqi Chen <chenerqi@gmail.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
      c95f1c5f
    • L
      ceph: fix buffer free while holding i_ceph_lock in fill_inode() · af8a85a4
      由 Luis Henriques 提交于 
      Calling ceph_buffer_put() in fill_inode() may result in freeing the
i_xattrs.blob buffer while holding the i_ceph_lock.  This can be fixed by
postponing the call until later, when the lock is released.

The following backtrace was triggered by fstests generic/070.

  BUG: sleeping function called from invalid context at mm/vmalloc.c:2283
  in_atomic(): 1, irqs_disabled(): 0, pid: 3852, name: kworker/0:4
  6 locks held by kworker/0:4/3852:
   #0: 000000004270f6bb ((wq_completion)ceph-msgr){+.+.}, at: process_one_work+0x1b8/0x5f0
   #1: 00000000eb420803 ((work_completion)(&(&con->work)->work)){+.+.}, at: process_one_work+0x1b8/0x5f0
   #2: 00000000be1c53a4 (&s->s_mutex){+.+.}, at: dispatch+0x288/0x1476
   #3: 00000000559cb958 (&mdsc->snap_rwsem){++++}, at: dispatch+0x2eb/0x1476
   #4: 000000000d5ebbae (&req->r_fill_mutex){+.+.}, at: dispatch+0x2fc/0x1476
   #5: 00000000a83d0514 (&(&ci->i_ceph_lock)->rlock){+.+.}, at: fill_inode.isra.0+0xf8/0xf70
  CPU: 0 PID: 3852 Comm: kworker/0:4 Not tainted 5.2.0+ #441
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014
  Workqueue: ceph-msgr ceph_con_workfn
  Call Trace:
   dump_stack+0x67/0x90
   ___might_sleep.cold+0x9f/0xb1
   vfree+0x4b/0x60
   ceph_buffer_release+0x1b/0x60
   fill_inode.isra.0+0xa9b/0xf70
   ceph_fill_trace+0x13b/0xc70
   ? dispatch+0x2eb/0x1476
   dispatch+0x320/0x1476
   ? __mutex_unlock_slowpath+0x4d/0x2a0
   ceph_con_workfn+0xc97/0x2ec0
   ? process_one_work+0x1b8/0x5f0
   process_one_work+0x244/0x5f0
   worker_thread+0x4d/0x3e0
   kthread+0x105/0x140
   ? process_one_work+0x5f0/0x5f0
   ? kthread_park+0x90/0x90
   ret_from_fork+0x3a/0x50
Signed-off-by: NLuis Henriques <lhenriques@suse.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
      af8a85a4
    • L
      ceph: fix buffer free while holding i_ceph_lock in __ceph_build_xattrs_blob() · 12fe3dda
      由 Luis Henriques 提交于 
      Calling ceph_buffer_put() in __ceph_build_xattrs_blob() may result in
freeing the i_xattrs.blob buffer while holding the i_ceph_lock.  This can
be fixed by having this function returning the old blob buffer and have
the callers of this function freeing it when the lock is released.

The following backtrace was triggered by fstests generic/117.

  BUG: sleeping function called from invalid context at mm/vmalloc.c:2283
  in_atomic(): 1, irqs_disabled(): 0, pid: 649, name: fsstress
  4 locks held by fsstress/649:
   #0: 00000000a7478e7e (&type->s_umount_key#19){++++}, at: iterate_supers+0x77/0xf0
   #1: 00000000f8de1423 (&(&ci->i_ceph_lock)->rlock){+.+.}, at: ceph_check_caps+0x7b/0xc60
   #2: 00000000562f2b27 (&s->s_mutex){+.+.}, at: ceph_check_caps+0x3bd/0xc60
   #3: 00000000f83ce16a (&mdsc->snap_rwsem){++++}, at: ceph_check_caps+0x3ed/0xc60
  CPU: 1 PID: 649 Comm: fsstress Not tainted 5.2.0+ #439
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014
  Call Trace:
   dump_stack+0x67/0x90
   ___might_sleep.cold+0x9f/0xb1
   vfree+0x4b/0x60
   ceph_buffer_release+0x1b/0x60
   __ceph_build_xattrs_blob+0x12b/0x170
   __send_cap+0x302/0x540
   ? __lock_acquire+0x23c/0x1e40
   ? __mark_caps_flushing+0x15c/0x280
   ? _raw_spin_unlock+0x24/0x30
   ceph_check_caps+0x5f0/0xc60
   ceph_flush_dirty_caps+0x7c/0x150
   ? __ia32_sys_fdatasync+0x20/0x20
   ceph_sync_fs+0x5a/0x130
   iterate_supers+0x8f/0xf0
   ksys_sync+0x4f/0xb0
   __ia32_sys_sync+0xa/0x10
   do_syscall_64+0x50/0x1c0
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x7fc6409ab617
Signed-off-by: NLuis Henriques <lhenriques@suse.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
      12fe3dda
    • L
      ceph: fix buffer free while holding i_ceph_lock in __ceph_setxattr() · 86968ef2
      由 Luis Henriques 提交于 
      Calling ceph_buffer_put() in __ceph_setxattr() may end up freeing the
i_xattrs.prealloc_blob buffer while holding the i_ceph_lock.  This can be
fixed by postponing the call until later, when the lock is released.

The following backtrace was triggered by fstests generic/117.

  BUG: sleeping function called from invalid context at mm/vmalloc.c:2283
  in_atomic(): 1, irqs_disabled(): 0, pid: 650, name: fsstress
  3 locks held by fsstress/650:
   #0: 00000000870a0fe8 (sb_writers#8){.+.+}, at: mnt_want_write+0x20/0x50
   #1: 00000000ba0c4c74 (&type->i_mutex_dir_key#6){++++}, at: vfs_setxattr+0x55/0xa0
   #2: 000000008dfbb3f2 (&(&ci->i_ceph_lock)->rlock){+.+.}, at: __ceph_setxattr+0x297/0x810
  CPU: 1 PID: 650 Comm: fsstress Not tainted 5.2.0+ #437
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58-prebuilt.qemu.org 04/01/2014
  Call Trace:
   dump_stack+0x67/0x90
   ___might_sleep.cold+0x9f/0xb1
   vfree+0x4b/0x60
   ceph_buffer_release+0x1b/0x60
   __ceph_setxattr+0x2b4/0x810
   __vfs_setxattr+0x66/0x80
   __vfs_setxattr_noperm+0x59/0xf0
   vfs_setxattr+0x81/0xa0
   setxattr+0x115/0x230
   ? filename_lookup+0xc9/0x140
   ? rcu_read_lock_sched_held+0x74/0x80
   ? rcu_sync_lockdep_assert+0x2e/0x60
   ? __sb_start_write+0x142/0x1a0
   ? mnt_want_write+0x20/0x50
   path_setxattr+0xba/0xd0
   __x64_sys_lsetxattr+0x24/0x30
   do_syscall_64+0x50/0x1c0
   entry_SYSCALL_64_after_hwframe+0x49/0xbe
  RIP: 0033:0x7ff23514359a
Signed-off-by: NLuis Henriques <lhenriques@suse.com>
Reviewed-by: NJeff Layton <jlayton@kernel.org>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
      86968ef2
  21. 21 8月, 2019 2 次提交
    • J
      io_uring: don't enter poll loop if we have CQEs pending · a3a0e43f
      由 Jens Axboe 提交于 
      We need to check if we have CQEs pending before starting a poll loop,
as those could be the events we will be spinning for (and hence we'll
find none). This can happen if a CQE triggers an error, or if it is
found by eg an IRQ before we get a chance to find it through polling.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      a3a0e43f
    • J
      io_uring: fix potential hang with polled IO · 500f9fba
      由 Jens Axboe 提交于 
      If a request issue ends up being punted to async context to avoid
blocking, we can get into a situation where the original application
enters the poll loop for that very request before it has been issued.
This should not be an issue, except that the polling will hold the
io_uring uring_ctx mutex for the duration of the poll. When the async
worker has actually issued the request, it needs to acquire this mutex
to add the request to the poll issued list. Since the application
polling is already holding this mutex, the workqueue sleeps on the
mutex forever, and the application thus never gets a chance to poll for
the very request it was interested in.

Fix this by ensuring that the polling drops the uring_ctx occasionally
if it's not making any progress.
Reported-by: NJeffrey M. Birnbaum <jmbnyc@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>
      500f9fba
  23. 20 8月, 2019 1 次提交