linux-stable.git/fs, branch v4.19.48

NFS: Fix a double unlock from nfs_match,get_client

2019-05-31T13:46:35+00:00

[ Upstream commit c260121a97a3e4df6536edbc2f26e166eff370ce ]

Now that nfs_match_client drops the nfs_client_lock, we should be
careful
to always return it in the same condition: locked.

Fixes: 950a578c6128 ("NFS: make nfs_match_client killable")
Reported-by: syzbot+228a82b263b5da91883d@syzkaller.appspotmail.com
Signed-off-by: Benjamin Coddington 
Signed-off-by: Anna Schumaker 
Signed-off-by: Sasha Levin

chardev: add additional check for minor range overlap

2019-05-31T13:46:27+00:00

[ Upstream commit de36e16d1557a0b6eb328bc3516359a12ba5c25c ]

Current overlap checking cannot correctly handle
a case which is baseminor < existing baseminor &&
baseminor + minorct > existing baseminor + minorct.

Signed-off-by: Chengguang Xu 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Sasha Levin

btrfs: Don't panic when we can't find a root key

2019-05-31T13:46:13+00:00

[ Upstream commit 7ac1e464c4d473b517bb784f30d40da1f842482e ]

When we failed to find a root key in btrfs_update_root(), we just panic.

That's definitely not cool, fix it by outputting an unique error
message, aborting current transaction and return -EUCLEAN. This should
not normally happen as the root has been used by the callers in some
way.

Reviewed-by: Filipe Manana 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Qu Wenruo 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba 
Signed-off-by: Sasha Levin

btrfs: fix panic during relocation after ENOSPC before writeback happens

2019-05-31T13:46:13+00:00

[ Upstream commit ff612ba7849964b1898fd3ccd1f56941129c6aab ]

We've been seeing the following sporadically throughout our fleet

panic: kernel BUG at fs/btrfs/relocation.c:4584!
netversion: 5.0-0
Backtrace:
 #0 [ffffc90003adb880] machine_kexec at ffffffff81041da8
 #1 [ffffc90003adb8c8] __crash_kexec at ffffffff8110396c
 #2 [ffffc90003adb988] crash_kexec at ffffffff811048ad
 #3 [ffffc90003adb9a0] oops_end at ffffffff8101c19a
 #4 [ffffc90003adb9c0] do_trap at ffffffff81019114
 #5 [ffffc90003adba00] do_error_trap at ffffffff810195d0
 #6 [ffffc90003adbab0] invalid_op at ffffffff81a00a9b
    [exception RIP: btrfs_reloc_cow_block+692]
    RIP: ffffffff8143b614  RSP: ffffc90003adbb68  RFLAGS: 00010246
    RAX: fffffffffffffff7  RBX: ffff8806b9c32000  RCX: ffff8806aad00690
    RDX: ffff880850b295e0  RSI: ffff8806b9c32000  RDI: ffff88084f205bd0
    RBP: ffff880849415000   R8: ffffc90003adbbe0   R9: ffff88085ac90000
    R10: ffff8805f7369140  R11: 0000000000000000  R12: ffff880850b295e0
    R13: ffff88084f205bd0  R14: 0000000000000000  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #7 [ffffc90003adbbb0] __btrfs_cow_block at ffffffff813bf1cd
 #8 [ffffc90003adbc28] btrfs_cow_block at ffffffff813bf4b3
 #9 [ffffc90003adbc78] btrfs_search_slot at ffffffff813c2e6c

The way relocation moves data extents is by creating a reloc inode and
preallocating extents in this inode and then copying the data into these
preallocated extents.  Once we've done this for all of our extents,
we'll write out these dirty pages, which marks the extent written, and
goes into btrfs_reloc_cow_block().  From here we get our current
reloc_control, which _should_ match the reloc_control for the current
block group we're relocating.

However if we get an ENOSPC in this path at some point we'll bail out,
never initiating writeback on this inode.  Not a huge deal, unless we
happen to be doing relocation on a different block group, and this block
group is now rc->stage == UPDATE_DATA_PTRS.  This trips the BUG_ON() in
btrfs_reloc_cow_block(), because we expect to be done modifying the data
inode.  We are in fact done modifying the metadata for the data inode
we're currently using, but not the one from the failed block group, and
thus we BUG_ON().

(This happens when writeback finishes for extents from the previous
group, when we are at btrfs_finish_ordered_io() which updates the data
reloc tree (inode item, drops/adds extent items, etc).)

Fix this by writing out the reloc data inode always, and then breaking
out of the loop after that point to keep from tripping this BUG_ON()
later.

Signed-off-by: Josef Bacik 
Reviewed-by: Filipe Manana 
[ add note from Filipe ]
Signed-off-by: David Sterba 
Signed-off-by: Sasha Levin

Btrfs: fix data bytes_may_use underflow with fallocate due to failed quota reserve

2019-05-31T13:46:13+00:00

[ Upstream commit 39ad317315887c2cb9a4347a93a8859326ddf136 ]

When doing fallocate, we first add the range to the reserve_list and
then reserve the quota.  If quota reservation fails, we'll release all
reserved parts of reserve_list.

However, cur_offset is not updated to indicate that this range is
already been inserted into the list.  Therefore, the same range is freed
twice.  Once at list_for_each_entry loop, and once at the end of the
function.  This will result in WARN_ON on bytes_may_use when we free the
remaining space.

At the end, under the 'out' label we have a call to:

   btrfs_free_reserved_data_space(inode, data_reserved, alloc_start, alloc_end - cur_offset);

The start offset, third argument, should be cur_offset.

Everything from alloc_start to cur_offset was freed by the
list_for_each_entry_safe_loop.

Fixes: 18513091af94 ("btrfs: update btrfs_space_info's bytes_may_use timely")
Reviewed-by: Filipe Manana 
Signed-off-by: Robbie Ko 
Signed-off-by: David Sterba 
Signed-off-by: Sasha Levin

gfs2: Fix occasional glock use-after-free

2019-05-31T13:46:07+00:00

[ Upstream commit 9287c6452d2b1f24ea8e84bd3cf6f3c6f267f712 ]

This patch has to do with the life cycle of glocks and buffers.  When
gfs2 metadata or journaled data is queued to be written, a gfs2_bufdata
object is assigned to track the buffer, and that is queued to various
lists, including the glock's gl_ail_list to indicate it's on the active
items list.  Once the page associated with the buffer has been written,
it is removed from the ail list, but its life isn't over until a revoke
has been successfully written.

So after the block is written, its bufdata object is moved from the
glock's gl_ail_list to a file-system-wide list of pending revokes,
sd_log_le_revoke.  At that point the glock still needs to track how many
revokes it contributed to that list (in gl_revokes) so that things like
glock go_sync can ensure all the metadata has been not only written, but
also revoked before the glock is granted to a different node.  This is
to guarantee journal replay doesn't replay the block once the glock has
been granted to another node.

Ross Lagerwall recently discovered a race in which an inode could be
evicted, and its glock freed after its ail list had been synced, but
while it still had unwritten revokes on the sd_log_le_revoke list.  The
evict decremented the glock reference count to zero, which allowed the
glock to be freed.  After the revoke was written, function
revoke_lo_after_commit tried to adjust the glock's gl_revokes counter
and clear its GLF_LFLUSH flag, at which time it referenced the freed
glock.

This patch fixes the problem by incrementing the glock reference count
in gfs2_add_revoke when the glock's first bufdata object is moved from
the glock to the global revokes list. Later, when the glock's last such
bufdata object is freed, the reference count is decremented. This
guarantees that whichever process finishes last (the revoke writing or
the evict) will properly free the glock, and neither will reference the
glock after it has been freed.

Reported-by: Ross Lagerwall 
Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Bob Peterson 
Signed-off-by: Sasha Levin

NFS: make nfs_match_client killable

2019-05-31T13:46:06+00:00

[ Upstream commit 950a578c6128c2886e295b9c7ecb0b6b22fcc92b ]

    Actually we don't do anything with return value from
    nfs_wait_client_init_complete in nfs_match_client, as a
    consequence if we get a fatal signal and client is not
    fully initialised, we'll loop to "again" label

    This has been proven to cause soft lockups on some scenarios
    (no-carrier but configured network interfaces)

Signed-off-by: Roberto Bergantinos Corpas 
Reviewed-by: Benjamin Coddington 
Signed-off-by: Anna Schumaker 
Signed-off-by: Sasha Levin

gfs2: Fix lru_count going negative

2019-05-31T13:46:06+00:00

[ Upstream commit 7881ef3f33bb80f459ea6020d1e021fc524a6348 ]

Under certain conditions, lru_count may drop below zero resulting in
a large amount of log spam like this:

vmscan: shrink_slab: gfs2_dump_glock+0x3b0/0x630 [gfs2] \
    negative objects to delete nr=-1

This happens as follows:
1) A glock is moved from lru_list to the dispose list and lru_count is
   decremented.
2) The dispose function calls cond_resched() and drops the lru lock.
3) Another thread takes the lru lock and tries to add the same glock to
   lru_list, checking if the glock is on an lru list.
4) It is on a list (actually the dispose list) and so it avoids
   incrementing lru_count.
5) The glock is moved to lru_list.
5) The original thread doesn't dispose it because it has been re-added
   to the lru list but the lru_count has still decreased by one.

Fix by checking if the LRU flag is set on the glock rather than checking
if the glock is on some list and rearrange the code so that the LRU flag
is added/removed precisely when the glock is added/removed from lru_list.

Signed-off-by: Ross Lagerwall 
Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Sasha Levin

Revert "btrfs: Honour FITRIM range constraints during free space trim"

2019-05-31T13:46:05+00:00

This reverts commit 8b13bb911f0c0c77d41e5ddc41ad3c127c356b8a.

There is currently no corresponding patch in master due to additional
changes that would be significantly different from plain revert in the
respective stable branch.

The range argument was not handled correctly and could cause trim to
overlap allocated areas or reach beyond the end of the device. The
address space that fitrim normally operates on is in logical
coordinates, while the discards are done on the physical device extents.
This distinction cannot be made with the current ioctl interface and
caused the confusion.

The bug depends on the layout of block groups and does not always
happen. The whole-fs trim (run by default by the fstrim tool) is not
affected.

Signed-off-by: David Sterba 
Signed-off-by: Greg Kroah-Hartman

acct_on(): don't mess with freeze protection

2019-05-31T13:46:05+00:00

commit 9419a3191dcb27f24478d288abaab697228d28e6 upstream.

What happens there is that we are replacing file->path.mnt of
a file we'd just opened with a clone and we need the write
count contribution to be transferred from original mount to
new one.  That's it.  We do *NOT* want any kind of freeze
protection for the duration of switchover.

IOW, we should just use __mnt_{want,drop}_write() for that
switchover; no need to bother with mnt_{want,drop}_write()
there.

Tested-by: Amir Goldstein 
Reported-by: syzbot+2a73a6ea9507b7112141@syzkaller.appspotmail.com
Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman