This was an old wart left over from how we previously did data
reservations. Before we could have people race in and take a
reservation while we were flushing space, so we needed to make sure we
looped a few times before giving up. Now that we're using the ticketing
infrastructure we don't have to worry about this and can drop the logic
altogether.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that data reservations follow the same pattern as metadata
reservations we can simply rename __reserve_metadata_bytes to
__reserve_bytes and use that helper for data reservations.
Things to keep in mind, btrfs_can_overcommit() returns 0 for data,
because we can never overcommit. We also will never pass in FLUSH_ALL
for data, so we'll simply be added to the priority list and go straight
into handle_reserve_ticket.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay reported a problem where generic/371 would fail sometimes with a
slow drive. The gist of the test is that we fallocate a file in
parallel with a pwrite of a different file. These two files combined
are smaller than the file system, but sometimes the pwrite would ENOSPC.
A fair bit of investigation uncovered the fact that the fallocate
workload was racing in and grabbing the free space that the pwrite
workload was trying to free up so it could make its own reservation.
After a few loops of this eventually the pwrite workload would error out
with an ENOSPC.
We've had the same problem with metadata as well, and we serialized all
metadata allocations to satisfy this problem. This wasn't usually a
problem with data because data reservations are more straightforward,
but obviously could still happen.
Fix this by not allowing reservations to occur if there are any pending
tickets waiting to be satisfied on the space info.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that we have all the infrastructure in place, use the ticketing
infrastructure to make data allocations. This still maintains the exact
same flushing behavior, but now we're using tickets to get our
reservations satisfied.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Create a new function btrfs_reserve_data_bytes() in order to handle data
reservations. This uses the new flush types and flush states to handle
making data reservations.
This patch specifically does not change any functionality, and is
purposefully not cleaned up in order to make bisection easier for the
future patches. The new helper is identical to the old helper in how it
handles data reservations. We first try to force a chunk allocation,
and then we run through the flush states all at once and in the same
order that they were done with the old helper.
Subsequent patches will clean this up and change the behavior of the
flushing, and it is important to keep those changes separate so we can
easily bisect down to the patch that caused the regression, rather than
the patch that made us start using the new infrastructure.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Data space flushing currently unconditionally commits the transaction
twice in a row, and the last time it checks if there's enough pinned
extents to satisfy its reservation before deciding to commit the
transaction for the 3rd and final time.
Encode this logic into may_commit_transaction(). In the next patch we
will pass in U64_MAX for bytes_needed the first two times, and the final
time we will pass in the actual bytes we need so the normal logic will
apply.
This patch exists solely to make the logical changes I will make to the
flushing state machine separate to make it easier to bisect any
performance related regressions.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently the way we do data reservations is by seeing if we have enough
space in our space_info. If we do not and we're a normal inode we'll
1) Attempt to force a chunk allocation until we can't anymore.
2) If that fails we'll flush delalloc, then commit the transaction, then
run the delayed iputs.
If we are a free space inode we're only allowed to force a chunk
allocation. In order to use the normal flushing mechanism we need to
encode this into a flush state array for normal inodes. Since both will
start with allocating chunks until the space info is full there is no
need to add this as a flush state, this will be handled specially.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Right now if the space is freed up after the ordered extents complete
(which is likely since the reservations are held until they complete),
we would do extra delalloc flushing before we'd notice that we didn't
have any more tickets. Fix this by moving the tickets check after our
wait_ordered_extents check.
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The original iteration of flushing had us flushing delalloc and then
checking to see if we could make our reservation, thus we were very
careful about how many pages we would flush at once.
But now that everything is async and we satisfy tickets as the space
becomes available we don't have to keep track of any of this, simply
try and flush the number of dirty inodes we may have in order to
reclaim space to make our reservation. This cleans up our delalloc
flushing significantly.
The async_pages stuff is dropped because btrfs_start_delalloc_roots()
handles the case that we generate async extents for us, so we no longer
require this extra logic.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We are going to use the ticket infrastructure for data, so use the
btrfs_space_info_free_bytes_may_use() helper in
btrfs_free_reserved_data_space_noquota() so we get the
btrfs_try_granting_tickets call when we free our reservation.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
If we have compression on we could free up more space than we reserved,
and thus be able to make a space reservation. Add the call for this
scenario.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When unpinning we were only calling btrfs_try_granting_tickets() if
global_rsv->space_info == space_info, which is problematic because we
use ticketing for SYSTEM chunks, and want to use it for DATA as well.
Fix this by moving this call outside of that if statement.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We were missing a call to btrfs_try_granting_tickets in
btrfs_free_reserved_bytes, so add it to handle the case where we're able
to satisfy an allocation because we've freed a pending reservation.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have traditionally used flush_space() to flush metadata space, so
we've been unconditionally using btrfs_metadata_alloc_profile() for our
profile to allocate a chunk. However if we're going to use this for
data we need to use btrfs_get_alloc_profile() on the space_info we pass
in.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently shrink_delalloc just looks up the metadata space info, but
this won't work if we're trying to reclaim space for data chunks. We
get the right space_info we want passed into flush_space, so simply pass
that along to shrink_delalloc.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Data allocations are going to want to pass in U64_MAX for flushing
space, adjust shrink_delalloc to handle this properly.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We don't use this anywhere inside of shrink_delalloc since 17024ad0a0
("Btrfs: fix early ENOSPC due to delalloc"), remove it.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have btrfs_wait_ordered_roots() which takes a u64 for nr, but
btrfs_start_delalloc_roots() that takes an int for nr, which makes using
them in conjunction, especially for something like (u64)-1, annoying and
inconsistent. Fix btrfs_start_delalloc_roots() to take a u64 for nr and
adjust start_delalloc_inodes() and it's callers appropriately.
This means we've adjusted start_delalloc_inodes() to take a pointer of
nr since we want to preserve the ability for start-delalloc_inodes() to
return an error, so simply make it do the nr adjusting as necessary.
Part of adjusting the callers to this means changing
btrfs_writeback_inodes_sb_nr() to take a u64 for items. This may be
confusing because it seems unrelated, but the caller of
btrfs_writeback_inodes_sb_nr() already passes in a u64, it's just the
function variable that needs to be changed.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
It can be accessed from 'fs_devices' as it's identical to
fs_info->fs_devices. Also add a comment about why we are calling the
function. No semantic changes.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
That BUG_ON cannot ever trigger because as the comment there states -
'err' is always set. Simply remove it as it brings no value.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Delete repeated words in fs/btrfs/.
{to, the, a, and old}
and change "into 2 part" to "into 2 parts".
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The current trace event always output result like this:
find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=4(METADATA)
find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=4(METADATA)
find_free_extent: root=2(EXTENT_TREE) len=8192 empty_size=0 flags=1(DATA)
find_free_extent: root=2(EXTENT_TREE) len=8192 empty_size=0 flags=1(DATA)
find_free_extent: root=2(EXTENT_TREE) len=4096 empty_size=0 flags=1(DATA)
find_free_extent: root=2(EXTENT_TREE) len=4096 empty_size=0 flags=1(DATA)
T's saying we're allocating data extent for EXTENT tree, which is not
even possible.
It's because we always use EXTENT tree as the owner for
trace_find_free_extent() without using the @root from
btrfs_reserve_extent().
This patch will change the parameter to use proper @root for
trace_find_free_extent():
Now it looks much better:
find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP)
find_free_extent: root=5(FS_TREE) len=8192 empty_size=0 flags=1(DATA)
find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=1(DATA)
find_free_extent: root=5(FS_TREE) len=4096 empty_size=0 flags=1(DATA)
find_free_extent: root=5(FS_TREE) len=8192 empty_size=0 flags=1(DATA)
find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP)
find_free_extent: root=7(CSUM_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP)
find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP)
find_free_extent: root=1(ROOT_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP)
Reported-by: Hans van Kranenburg <hans@knorrie.org>
CC: stable@vger.kernel.org # 5.4+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.9-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Two more fixes.
One is for a lockdep warning/lockup (also caught by syzbot), that one
has been seen in practice. Regarding the other syzbot reports
mentioned last time, they don't seem to be urgent and reliably
reproducible so they'll be fixed later.
The second fix is for a potential corruption when device replace
finishes and the in-memory state of trim is not copied to the new
device"
* tag 'for-5.9-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix filesystem corruption after a device replace
btrfs: move btrfs_rm_dev_replace_free_srcdev outside of all locks
btrfs: move btrfs_scratch_superblocks into btrfs_dev_replace_finishing
We use a device's allocation state tree to track ranges in a device used
for allocated chunks, and we set ranges in this tree when allocating a new
chunk. However after a device replace operation, we were not setting the
allocated ranges in the new device's allocation state tree, so that tree
is empty after a device replace.
This means that a fitrim operation after a device replace will trim the
device ranges that have allocated chunks and extents, as we trim every
range for which there is not a range marked in the device's allocation
state tree. It is also important during chunk allocation, since the
device's allocation state is used to determine if a range is already
allocated when allocating a new chunk.
This is trivial to reproduce and the following script triggers the bug:
$ cat reproducer.sh
#!/bin/bash
DEV1="/dev/sdg"
DEV2="/dev/sdh"
DEV3="/dev/sdi"
wipefs -a $DEV1 $DEV2 $DEV3 &> /dev/null
# Create a raid1 test fs on 2 devices.
mkfs.btrfs -f -m raid1 -d raid1 $DEV1 $DEV2 > /dev/null
mount $DEV1 /mnt/btrfs
xfs_io -f -c "pwrite -S 0xab 0 10M" /mnt/btrfs/foo
echo "Starting to replace $DEV1 with $DEV3"
btrfs replace start -B $DEV1 $DEV3 /mnt/btrfs
echo
echo "Running fstrim"
fstrim /mnt/btrfs
echo
echo "Unmounting filesystem"
umount /mnt/btrfs
echo "Mounting filesystem in degraded mode using $DEV3 only"
wipefs -a $DEV1 $DEV2 &> /dev/null
mount -o degraded $DEV3 /mnt/btrfs
if [ $? -ne 0 ]; then
dmesg | tail
echo
echo "Failed to mount in degraded mode"
exit 1
fi
echo
echo "File foo data (expected all bytes = 0xab):"
od -A d -t x1 /mnt/btrfs/foo
umount /mnt/btrfs
When running the reproducer:
$ ./replace-test.sh
wrote 10485760/10485760 bytes at offset 0
10 MiB, 2560 ops; 0.0901 sec (110.877 MiB/sec and 28384.5216 ops/sec)
Starting to replace /dev/sdg with /dev/sdi
Running fstrim
Unmounting filesystem
Mounting filesystem in degraded mode using /dev/sdi only
mount: /mnt/btrfs: wrong fs type, bad option, bad superblock on /dev/sdi, missing codepage or helper program, or other error.
[19581.748641] BTRFS info (device sdg): dev_replace from /dev/sdg (devid 1) to /dev/sdi started
[19581.803842] BTRFS info (device sdg): dev_replace from /dev/sdg (devid 1) to /dev/sdi finished
[19582.208293] BTRFS info (device sdi): allowing degraded mounts
[19582.208298] BTRFS info (device sdi): disk space caching is enabled
[19582.208301] BTRFS info (device sdi): has skinny extents
[19582.212853] BTRFS warning (device sdi): devid 2 uuid 1f731f47-e1bb-4f00-bfbb-9e5a0cb4ba9f is missing
[19582.213904] btree_readpage_end_io_hook: 25839 callbacks suppressed
[19582.213907] BTRFS error (device sdi): bad tree block start, want 30490624 have 0
[19582.214780] BTRFS warning (device sdi): failed to read root (objectid=7): -5
[19582.231576] BTRFS error (device sdi): open_ctree failed
Failed to mount in degraded mode
So fix by setting all allocated ranges in the replace target device when
the replace operation is finishing, when we are holding the chunk mutex
and we can not race with new chunk allocations.
A test case for fstests follows soon.
Fixes: 1c11b63eff ("btrfs: replace pending/pinned chunks lists with io tree")
CC: stable@vger.kernel.org # 5.2+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We need to move the closing of the src_device out of all the device
replace locking, but we definitely want to zero out the superblock
before we commit the last time to make sure the device is properly
removed. Handle this by pushing btrfs_scratch_superblocks into
btrfs_dev_replace_finishing, and then later on we'll move the src_device
closing and freeing stuff where we need it to be.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Just checking SB_I_CGROUPWB for cgroup writeback support is enough.
Either the file system allocates its own bdi (e.g. btrfs), in which case
it is known to support cgroup writeback, or the bdi comes from the block
layer, which always supports cgroup writeback.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Set up a readahead size by default, as very few users have a good
reason to change it. This means code, ecryptfs, and orangefs now
set up the values while they were previously missing it, while ubifs,
mtd and vboxsf manually set it to 0 to avoid readahead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: David Sterba <dsterba@suse.com> [btrfs]
Acked-by: Richard Weinberger <richard@nod.at> [ubifs, mtd]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-5.9-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"syzkaller started to hit us with reports, here's a fix for one type
(stack overflow when printing checksums on read error).
The other patch is a fix for sysfs object, we have a test for that and
it leads to a crash."
* tag 'for-5.9-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix put of uninitialized kobject after seed device delete
btrfs: fix overflow when copying corrupt csums for a message
The following test case leads to NULL kobject free error:
mount seed /mnt
add sprout to /mnt
umount /mnt
mount sprout to /mnt
delete seed
kobject: '(null)' (00000000dd2b87e4): is not initialized, yet kobject_put() is being called.
WARNING: CPU: 1 PID: 15784 at lib/kobject.c:736 kobject_put+0x80/0x350
RIP: 0010:kobject_put+0x80/0x350
::
Call Trace:
btrfs_sysfs_remove_devices_dir+0x6e/0x160 [btrfs]
btrfs_rm_device.cold+0xa8/0x298 [btrfs]
btrfs_ioctl+0x206c/0x22a0 [btrfs]
ksys_ioctl+0xe2/0x140
__x64_sys_ioctl+0x1e/0x29
do_syscall_64+0x96/0x150
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f4047c6288b
::
This is because, at the end of the seed device-delete, we try to remove
the seed's devid sysfs entry. But for the seed devices under the sprout
fs, we don't initialize the devid kobject yet. So add a kobject state
check, which takes care of the bug.
Fixes: 668e48af7a ("btrfs: sysfs, add devid/dev_state kobject and device attributes")
CC: stable@vger.kernel.org # 5.6+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.9-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fix from David Sterba:
"One of the recent lockdep fixes introduced a bug that breaks the
search ioctl, which is used by some applications (bees, compsize). The
patch made it to stable trees so we need this fixup to make it work
again"
* tag 'for-5.9-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix wrong address when faulting in pages in the search ioctl
When faulting in the pages for the user supplied buffer for the search
ioctl, we are passing only the base address of the buffer to the function
fault_in_pages_writeable(). This means that after the first iteration of
the while loop that searches for leaves, when we have a non-zero offset,
stored in 'sk_offset', we try to fault in a wrong page range.
So fix this by adding the offset in 'sk_offset' to the base address of the
user supplied buffer when calling fault_in_pages_writeable().
Several users have reported that the applications compsize and bees have
started to operate incorrectly since commit a48b73eca4 ("btrfs: fix
potential deadlock in the search ioctl") was added to stable trees, and
these applications make heavy use of the search ioctls. This fixes their
issues.
Link: https://lore.kernel.org/linux-btrfs/632b888d-a3c3-b085-cdf5-f9bb61017d92@lechevalier.se/
Link: https://github.com/kilobyte/compsize/issues/34
Fixes: a48b73eca4 ("btrfs: fix potential deadlock in the search ioctl")
CC: stable@vger.kernel.org # 4.4+
Tested-by: A L <mail@lechevalier.se>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.9-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A few more fixes:
- regression fix for a crash after failed snapshot creation
- one more lockep fix: use nofs allocation when allocating missing
device
- fix reloc tree leak on degraded mount
- make some extent buffer alignment checks less strict to mount
filesystems created by btrfs-convert"
* tag 'for-5.9-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix NULL pointer dereference after failure to create snapshot
btrfs: free data reloc tree on failed mount
btrfs: require only sector size alignment for parent eb bytenr
btrfs: fix lockdep splat in add_missing_dev
While testing a weird problem with -o degraded, I noticed I was getting
leaked root errors
BTRFS warning (device loop0): writable mount is not allowed due to too many missing devices
BTRFS error (device loop0): open_ctree failed
BTRFS error (device loop0): leaked root -9-0 refcount 1
This is the DATA_RELOC root, which gets read before the other fs roots,
but is included in the fs roots radix tree. Handle this by adding a
btrfs_drop_and_free_fs_root() on the data reloc root if it exists. This
is ok to do here if we fail further up because we will only drop the ref
if we delete the root from the radix tree, and all other cleanup won't
be duplicated.
CC: stable@vger.kernel.org # 5.8+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
A completely sane converted fs will cause kernel warning at balance
time:
[ 1557.188633] BTRFS info (device sda7): relocating block group 8162107392 flags data
[ 1563.358078] BTRFS info (device sda7): found 11722 extents
[ 1563.358277] BTRFS info (device sda7): leaf 7989321728 gen 95 total ptrs 213 free space 3458 owner 2
[ 1563.358280] item 0 key (7984947200 169 0) itemoff 16250 itemsize 33
[ 1563.358281] extent refs 1 gen 90 flags 2
[ 1563.358282] ref#0: tree block backref root 4
[ 1563.358285] item 1 key (7985602560 169 0) itemoff 16217 itemsize 33
[ 1563.358286] extent refs 1 gen 93 flags 258
[ 1563.358287] ref#0: shared block backref parent 7985602560
[ 1563.358288] (parent 7985602560 is NOT ALIGNED to nodesize 16384)
[ 1563.358290] item 2 key (7985635328 169 0) itemoff 16184 itemsize 33
...
[ 1563.358995] BTRFS error (device sda7): eb 7989321728 invalid extent inline ref type 182
[ 1563.358996] ------------[ cut here ]------------
[ 1563.359005] WARNING: CPU: 14 PID: 2930 at 0xffffffff9f231766
Then with transaction abort, and obviously failed to balance the fs.
[CAUSE]
That mentioned inline ref type 182 is completely sane, it's
BTRFS_SHARED_BLOCK_REF_KEY, it's some extra check making kernel to
believe it's invalid.
Commit 64ecdb647d ("Btrfs: add one more sanity check for shared ref
type") introduced extra checks for backref type.
One of the requirement is, parent bytenr must be aligned to node size,
which is not correct.
One example is like this:
0 1G 1G+4K 2G 2G+4K
| |///////////////////|//| <- A chunk starts at 1G+4K
| | <- A tree block get reserved at bytenr 1G+4K
Then we have a valid tree block at bytenr 1G+4K, but not aligned to
nodesize (16K).
Such chunk is not ideal, but current kernel can handle it pretty well.
We may warn about such tree block in the future, but should not reject
them.
[FIX]
Change the alignment requirement from node size alignment to sector size
alignment.
Also, to make our lives a little easier, also output @iref when
btrfs_get_extent_inline_ref_type() failed, so we can locate the item
easier.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=205475
Fixes: 64ecdb647d ("Btrfs: add one more sanity check for shared ref type")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
[ update comments and messages ]
Signed-off-by: David Sterba <dsterba@suse.com>
Nikolay reported a lockdep splat in generic/476 that I could reproduce
with btrfs/187.
======================================================
WARNING: possible circular locking dependency detected
5.9.0-rc2+ #1 Tainted: G W
------------------------------------------------------
kswapd0/100 is trying to acquire lock:
ffff9e8ef38b6268 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x3f/0x330
but task is already holding lock:
ffffffffa9d74700 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (fs_reclaim){+.+.}-{0:0}:
fs_reclaim_acquire+0x65/0x80
slab_pre_alloc_hook.constprop.0+0x20/0x200
kmem_cache_alloc_trace+0x3a/0x1a0
btrfs_alloc_device+0x43/0x210
add_missing_dev+0x20/0x90
read_one_chunk+0x301/0x430
btrfs_read_sys_array+0x17b/0x1b0
open_ctree+0xa62/0x1896
btrfs_mount_root.cold+0x12/0xea
legacy_get_tree+0x30/0x50
vfs_get_tree+0x28/0xc0
vfs_kern_mount.part.0+0x71/0xb0
btrfs_mount+0x10d/0x379
legacy_get_tree+0x30/0x50
vfs_get_tree+0x28/0xc0
path_mount+0x434/0xc00
__x64_sys_mount+0xe3/0x120
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
-> #1 (&fs_info->chunk_mutex){+.+.}-{3:3}:
__mutex_lock+0x7e/0x7e0
btrfs_chunk_alloc+0x125/0x3a0
find_free_extent+0xdf6/0x1210
btrfs_reserve_extent+0xb3/0x1b0
btrfs_alloc_tree_block+0xb0/0x310
alloc_tree_block_no_bg_flush+0x4a/0x60
__btrfs_cow_block+0x11a/0x530
btrfs_cow_block+0x104/0x220
btrfs_search_slot+0x52e/0x9d0
btrfs_lookup_inode+0x2a/0x8f
__btrfs_update_delayed_inode+0x80/0x240
btrfs_commit_inode_delayed_inode+0x119/0x120
btrfs_evict_inode+0x357/0x500
evict+0xcf/0x1f0
vfs_rmdir.part.0+0x149/0x160
do_rmdir+0x136/0x1a0
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
-> #0 (&delayed_node->mutex){+.+.}-{3:3}:
__lock_acquire+0x1184/0x1fa0
lock_acquire+0xa4/0x3d0
__mutex_lock+0x7e/0x7e0
__btrfs_release_delayed_node.part.0+0x3f/0x330
btrfs_evict_inode+0x24c/0x500
evict+0xcf/0x1f0
dispose_list+0x48/0x70
prune_icache_sb+0x44/0x50
super_cache_scan+0x161/0x1e0
do_shrink_slab+0x178/0x3c0
shrink_slab+0x17c/0x290
shrink_node+0x2b2/0x6d0
balance_pgdat+0x30a/0x670
kswapd+0x213/0x4c0
kthread+0x138/0x160
ret_from_fork+0x1f/0x30
other info that might help us debug this:
Chain exists of:
&delayed_node->mutex --> &fs_info->chunk_mutex --> fs_reclaim
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(&fs_info->chunk_mutex);
lock(fs_reclaim);
lock(&delayed_node->mutex);
*** DEADLOCK ***
3 locks held by kswapd0/100:
#0: ffffffffa9d74700 (fs_reclaim){+.+.}-{0:0}, at: __fs_reclaim_acquire+0x5/0x30
#1: ffffffffa9d65c50 (shrinker_rwsem){++++}-{3:3}, at: shrink_slab+0x115/0x290
#2: ffff9e8e9da260e0 (&type->s_umount_key#48){++++}-{3:3}, at: super_cache_scan+0x38/0x1e0
stack backtrace:
CPU: 1 PID: 100 Comm: kswapd0 Tainted: G W 5.9.0-rc2+ #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
dump_stack+0x92/0xc8
check_noncircular+0x12d/0x150
__lock_acquire+0x1184/0x1fa0
lock_acquire+0xa4/0x3d0
? __btrfs_release_delayed_node.part.0+0x3f/0x330
__mutex_lock+0x7e/0x7e0
? __btrfs_release_delayed_node.part.0+0x3f/0x330
? __btrfs_release_delayed_node.part.0+0x3f/0x330
? lock_acquire+0xa4/0x3d0
? btrfs_evict_inode+0x11e/0x500
? find_held_lock+0x2b/0x80
__btrfs_release_delayed_node.part.0+0x3f/0x330
btrfs_evict_inode+0x24c/0x500
evict+0xcf/0x1f0
dispose_list+0x48/0x70
prune_icache_sb+0x44/0x50
super_cache_scan+0x161/0x1e0
do_shrink_slab+0x178/0x3c0
shrink_slab+0x17c/0x290
shrink_node+0x2b2/0x6d0
balance_pgdat+0x30a/0x670
kswapd+0x213/0x4c0
? _raw_spin_unlock_irqrestore+0x46/0x60
? add_wait_queue_exclusive+0x70/0x70
? balance_pgdat+0x670/0x670
kthread+0x138/0x160
? kthread_create_worker_on_cpu+0x40/0x40
ret_from_fork+0x1f/0x30
This is because we are holding the chunk_mutex when we call
btrfs_alloc_device, which does a GFP_KERNEL allocation. We don't want
to switch that to a GFP_NOFS lock because this is the only place where
it matters. So instead use memalloc_nofs_save() around the allocation
in order to avoid the lockdep splat.
Reported-by: Nikolay Borisov <nborisov@suse.com>
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.9-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"Two small fixes and a bunch of lockdep fixes for warnings that show up
with an upcoming tree locking update but are valid with current locks
as well"
* tag 'for-5.9-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: tree-checker: fix the error message for transid error
btrfs: set the lockdep class for log tree extent buffers
btrfs: set the correct lockdep class for new nodes
btrfs: allocate scrub workqueues outside of locks
btrfs: fix potential deadlock in the search ioctl
btrfs: drop path before adding new uuid tree entry
btrfs: block-group: fix free-space bitmap threshold
The error message for inode transid is the same as for inode generation,
which makes us unable to detect the real problem.
Reported-by: Tyler Richmond <t.d.richmond@gmail.com>
Fixes: 496245cac5 ("btrfs: tree-checker: Verify inode item")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
These are special extent buffers that get rewound in order to lookup
the state of the tree at a specific point in time. As such they do not
go through the normal initialization paths that set their lockdep class,
so handle them appropriately when they are created and before they are
locked.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When flipping over to the rw_semaphore I noticed I'd get a lockdep splat
in replace_path(), which is weird because we're swapping the reloc root
with the actual target root. Turns out this is because we're using the
root->root_key.objectid as the root id for the newly allocated tree
block when setting the lockdep class, however we need to be using the
actual owner of this new block, which is saved in owner.
The affected path is through btrfs_copy_root as all other callers of
btrfs_alloc_tree_block (which calls init_new_buffer) have root_objectid
== root->root_key.objectid .
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
I got the following lockdep splat while testing:
======================================================
WARNING: possible circular locking dependency detected
5.8.0-rc7-00172-g021118712e59 #932 Not tainted
------------------------------------------------------
btrfs/229626 is trying to acquire lock:
ffffffff828513f0 (cpu_hotplug_lock){++++}-{0:0}, at: alloc_workqueue+0x378/0x450
but task is already holding lock:
ffff889dd3889518 (&fs_info->scrub_lock){+.+.}-{3:3}, at: btrfs_scrub_dev+0x11c/0x630
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #7 (&fs_info->scrub_lock){+.+.}-{3:3}:
__mutex_lock+0x9f/0x930
btrfs_scrub_dev+0x11c/0x630
btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
btrfs_ioctl+0x2799/0x30a0
ksys_ioctl+0x83/0xc0
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x50/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
-> #6 (&fs_devs->device_list_mutex){+.+.}-{3:3}:
__mutex_lock+0x9f/0x930
btrfs_run_dev_stats+0x49/0x480
commit_cowonly_roots+0xb5/0x2a0
btrfs_commit_transaction+0x516/0xa60
sync_filesystem+0x6b/0x90
generic_shutdown_super+0x22/0x100
kill_anon_super+0xe/0x30
btrfs_kill_super+0x12/0x20
deactivate_locked_super+0x29/0x60
cleanup_mnt+0xb8/0x140
task_work_run+0x6d/0xb0
__prepare_exit_to_usermode+0x1cc/0x1e0
do_syscall_64+0x5c/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
-> #5 (&fs_info->tree_log_mutex){+.+.}-{3:3}:
__mutex_lock+0x9f/0x930
btrfs_commit_transaction+0x4bb/0xa60
sync_filesystem+0x6b/0x90
generic_shutdown_super+0x22/0x100
kill_anon_super+0xe/0x30
btrfs_kill_super+0x12/0x20
deactivate_locked_super+0x29/0x60
cleanup_mnt+0xb8/0x140
task_work_run+0x6d/0xb0
__prepare_exit_to_usermode+0x1cc/0x1e0
do_syscall_64+0x5c/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
-> #4 (&fs_info->reloc_mutex){+.+.}-{3:3}:
__mutex_lock+0x9f/0x930
btrfs_record_root_in_trans+0x43/0x70
start_transaction+0xd1/0x5d0
btrfs_dirty_inode+0x42/0xd0
touch_atime+0xa1/0xd0
btrfs_file_mmap+0x3f/0x60
mmap_region+0x3a4/0x640
do_mmap+0x376/0x580
vm_mmap_pgoff+0xd5/0x120
ksys_mmap_pgoff+0x193/0x230
do_syscall_64+0x50/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
-> #3 (&mm->mmap_lock#2){++++}-{3:3}:
__might_fault+0x68/0x90
_copy_to_user+0x1e/0x80
perf_read+0x141/0x2c0
vfs_read+0xad/0x1b0
ksys_read+0x5f/0xe0
do_syscall_64+0x50/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
-> #2 (&cpuctx_mutex){+.+.}-{3:3}:
__mutex_lock+0x9f/0x930
perf_event_init_cpu+0x88/0x150
perf_event_init+0x1db/0x20b
start_kernel+0x3ae/0x53c
secondary_startup_64+0xa4/0xb0
-> #1 (pmus_lock){+.+.}-{3:3}:
__mutex_lock+0x9f/0x930
perf_event_init_cpu+0x4f/0x150
cpuhp_invoke_callback+0xb1/0x900
_cpu_up.constprop.26+0x9f/0x130
cpu_up+0x7b/0xc0
bringup_nonboot_cpus+0x4f/0x60
smp_init+0x26/0x71
kernel_init_freeable+0x110/0x258
kernel_init+0xa/0x103
ret_from_fork+0x1f/0x30
-> #0 (cpu_hotplug_lock){++++}-{0:0}:
__lock_acquire+0x1272/0x2310
lock_acquire+0x9e/0x360
cpus_read_lock+0x39/0xb0
alloc_workqueue+0x378/0x450
__btrfs_alloc_workqueue+0x15d/0x200
btrfs_alloc_workqueue+0x51/0x160
scrub_workers_get+0x5a/0x170
btrfs_scrub_dev+0x18c/0x630
btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
btrfs_ioctl+0x2799/0x30a0
ksys_ioctl+0x83/0xc0
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x50/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
other info that might help us debug this:
Chain exists of:
cpu_hotplug_lock --> &fs_devs->device_list_mutex --> &fs_info->scrub_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&fs_info->scrub_lock);
lock(&fs_devs->device_list_mutex);
lock(&fs_info->scrub_lock);
lock(cpu_hotplug_lock);
*** DEADLOCK ***
2 locks held by btrfs/229626:
#0: ffff88bfe8bb86e0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_scrub_dev+0xbd/0x630
#1: ffff889dd3889518 (&fs_info->scrub_lock){+.+.}-{3:3}, at: btrfs_scrub_dev+0x11c/0x630
stack backtrace:
CPU: 15 PID: 229626 Comm: btrfs Kdump: loaded Not tainted 5.8.0-rc7-00172-g021118712e59 #932
Hardware name: Quanta Tioga Pass Single Side 01-0030993006/Tioga Pass Single Side, BIOS F08_3A18 12/20/2018
Call Trace:
dump_stack+0x78/0xa0
check_noncircular+0x165/0x180
__lock_acquire+0x1272/0x2310
lock_acquire+0x9e/0x360
? alloc_workqueue+0x378/0x450
cpus_read_lock+0x39/0xb0
? alloc_workqueue+0x378/0x450
alloc_workqueue+0x378/0x450
? rcu_read_lock_sched_held+0x52/0x80
__btrfs_alloc_workqueue+0x15d/0x200
btrfs_alloc_workqueue+0x51/0x160
scrub_workers_get+0x5a/0x170
btrfs_scrub_dev+0x18c/0x630
? start_transaction+0xd1/0x5d0
btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
btrfs_ioctl+0x2799/0x30a0
? do_sigaction+0x102/0x250
? lockdep_hardirqs_on_prepare+0xca/0x160
? _raw_spin_unlock_irq+0x24/0x30
? trace_hardirqs_on+0x1c/0xe0
? _raw_spin_unlock_irq+0x24/0x30
? do_sigaction+0x102/0x250
? ksys_ioctl+0x83/0xc0
ksys_ioctl+0x83/0xc0
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x50/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
This happens because we're allocating the scrub workqueues under the
scrub and device list mutex, which brings in a whole host of other
dependencies.
Because the work queue allocation is done with GFP_KERNEL, it can
trigger reclaim, which can lead to a transaction commit, which in turns
needs the device_list_mutex, it can lead to a deadlock. A different
problem for which this fix is a solution.
Fix this by moving the actual allocation outside of the
scrub lock, and then only take the lock once we're ready to actually
assign them to the fs_info. We'll now have to cleanup the workqueues in
a few more places, so I've added a helper to do the refcount dance to
safely free the workqueues.
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
With the conversion of the tree locks to rwsem I got the following
lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
5.8.0-rc7-00165-g04ec4da5f45f-dirty #922 Not tainted
------------------------------------------------------
compsize/11122 is trying to acquire lock:
ffff889fabca8768 (&mm->mmap_lock#2){++++}-{3:3}, at: __might_fault+0x3e/0x90
but task is already holding lock:
ffff889fe720fe40 (btrfs-fs-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (btrfs-fs-00){++++}-{3:3}:
down_write_nested+0x3b/0x70
__btrfs_tree_lock+0x24/0x120
btrfs_search_slot+0x756/0x990
btrfs_lookup_inode+0x3a/0xb4
__btrfs_update_delayed_inode+0x93/0x270
btrfs_async_run_delayed_root+0x168/0x230
btrfs_work_helper+0xd4/0x570
process_one_work+0x2ad/0x5f0
worker_thread+0x3a/0x3d0
kthread+0x133/0x150
ret_from_fork+0x1f/0x30
-> #1 (&delayed_node->mutex){+.+.}-{3:3}:
__mutex_lock+0x9f/0x930
btrfs_delayed_update_inode+0x50/0x440
btrfs_update_inode+0x8a/0xf0
btrfs_dirty_inode+0x5b/0xd0
touch_atime+0xa1/0xd0
btrfs_file_mmap+0x3f/0x60
mmap_region+0x3a4/0x640
do_mmap+0x376/0x580
vm_mmap_pgoff+0xd5/0x120
ksys_mmap_pgoff+0x193/0x230
do_syscall_64+0x50/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
-> #0 (&mm->mmap_lock#2){++++}-{3:3}:
__lock_acquire+0x1272/0x2310
lock_acquire+0x9e/0x360
__might_fault+0x68/0x90
_copy_to_user+0x1e/0x80
copy_to_sk.isra.32+0x121/0x300
search_ioctl+0x106/0x200
btrfs_ioctl_tree_search_v2+0x7b/0xf0
btrfs_ioctl+0x106f/0x30a0
ksys_ioctl+0x83/0xc0
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x50/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
other info that might help us debug this:
Chain exists of:
&mm->mmap_lock#2 --> &delayed_node->mutex --> btrfs-fs-00
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(btrfs-fs-00);
lock(&delayed_node->mutex);
lock(btrfs-fs-00);
lock(&mm->mmap_lock#2);
*** DEADLOCK ***
1 lock held by compsize/11122:
#0: ffff889fe720fe40 (btrfs-fs-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180
stack backtrace:
CPU: 17 PID: 11122 Comm: compsize Kdump: loaded Not tainted 5.8.0-rc7-00165-g04ec4da5f45f-dirty #922
Hardware name: Quanta Tioga Pass Single Side 01-0030993006/Tioga Pass Single Side, BIOS F08_3A18 12/20/2018
Call Trace:
dump_stack+0x78/0xa0
check_noncircular+0x165/0x180
__lock_acquire+0x1272/0x2310
lock_acquire+0x9e/0x360
? __might_fault+0x3e/0x90
? find_held_lock+0x72/0x90
__might_fault+0x68/0x90
? __might_fault+0x3e/0x90
_copy_to_user+0x1e/0x80
copy_to_sk.isra.32+0x121/0x300
? btrfs_search_forward+0x2a6/0x360
search_ioctl+0x106/0x200
btrfs_ioctl_tree_search_v2+0x7b/0xf0
btrfs_ioctl+0x106f/0x30a0
? __do_sys_newfstat+0x5a/0x70
? ksys_ioctl+0x83/0xc0
ksys_ioctl+0x83/0xc0
__x64_sys_ioctl+0x16/0x20
do_syscall_64+0x50/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The problem is we're doing a copy_to_user() while holding tree locks,
which can deadlock if we have to do a page fault for the copy_to_user().
This exists even without my locking changes, so it needs to be fixed.
Rework the search ioctl to do the pre-fault and then
copy_to_user_nofault for the copying.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
With the conversion of the tree locks to rwsem I got the following
lockdep splat:
======================================================
WARNING: possible circular locking dependency detected
5.8.0-rc7-00167-g0d7ba0c5b375-dirty #925 Not tainted
------------------------------------------------------
btrfs-uuid/7955 is trying to acquire lock:
ffff88bfbafec0f8 (btrfs-root-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180
but task is already holding lock:
ffff88bfbafef2a8 (btrfs-uuid-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (btrfs-uuid-00){++++}-{3:3}:
down_read_nested+0x3e/0x140
__btrfs_tree_read_lock+0x39/0x180
__btrfs_read_lock_root_node+0x3a/0x50
btrfs_search_slot+0x4bd/0x990
btrfs_uuid_tree_add+0x89/0x2d0
btrfs_uuid_scan_kthread+0x330/0x390
kthread+0x133/0x150
ret_from_fork+0x1f/0x30
-> #0 (btrfs-root-00){++++}-{3:3}:
__lock_acquire+0x1272/0x2310
lock_acquire+0x9e/0x360
down_read_nested+0x3e/0x140
__btrfs_tree_read_lock+0x39/0x180
__btrfs_read_lock_root_node+0x3a/0x50
btrfs_search_slot+0x4bd/0x990
btrfs_find_root+0x45/0x1b0
btrfs_read_tree_root+0x61/0x100
btrfs_get_root_ref.part.50+0x143/0x630
btrfs_uuid_tree_iterate+0x207/0x314
btrfs_uuid_rescan_kthread+0x12/0x50
kthread+0x133/0x150
ret_from_fork+0x1f/0x30
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(btrfs-uuid-00);
lock(btrfs-root-00);
lock(btrfs-uuid-00);
lock(btrfs-root-00);
*** DEADLOCK ***
1 lock held by btrfs-uuid/7955:
#0: ffff88bfbafef2a8 (btrfs-uuid-00){++++}-{3:3}, at: __btrfs_tree_read_lock+0x39/0x180
stack backtrace:
CPU: 73 PID: 7955 Comm: btrfs-uuid Kdump: loaded Not tainted 5.8.0-rc7-00167-g0d7ba0c5b375-dirty #925
Hardware name: Quanta Tioga Pass Single Side 01-0030993006/Tioga Pass Single Side, BIOS F08_3A18 12/20/2018
Call Trace:
dump_stack+0x78/0xa0
check_noncircular+0x165/0x180
__lock_acquire+0x1272/0x2310
lock_acquire+0x9e/0x360
? __btrfs_tree_read_lock+0x39/0x180
? btrfs_root_node+0x1c/0x1d0
down_read_nested+0x3e/0x140
? __btrfs_tree_read_lock+0x39/0x180
__btrfs_tree_read_lock+0x39/0x180
__btrfs_read_lock_root_node+0x3a/0x50
btrfs_search_slot+0x4bd/0x990
btrfs_find_root+0x45/0x1b0
btrfs_read_tree_root+0x61/0x100
btrfs_get_root_ref.part.50+0x143/0x630
btrfs_uuid_tree_iterate+0x207/0x314
? btree_readpage+0x20/0x20
btrfs_uuid_rescan_kthread+0x12/0x50
kthread+0x133/0x150
? kthread_create_on_node+0x60/0x60
ret_from_fork+0x1f/0x30
This problem exists because we have two different rescan threads,
btrfs_uuid_scan_kthread which creates the uuid tree, and
btrfs_uuid_tree_iterate that goes through and updates or deletes any out
of date roots. The problem is they both do things in different order.
btrfs_uuid_scan_kthread() reads the tree_root, and then inserts entries
into the uuid_root. btrfs_uuid_tree_iterate() scans the uuid_root, but
then does a btrfs_get_fs_root() which can read from the tree_root.
It's actually easy enough to not be holding the path in
btrfs_uuid_scan_kthread() when we add a uuid entry, as we already drop
it further down and re-start the search when we loop. So simply move
the path release before we add our entry to the uuid tree.
This also fixes a problem where we're holding a path open after we do
btrfs_end_transaction(), which has it's own problems.
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
After commit 9afc66498a ("btrfs: block-group: refactor how we read one
block group item"), cache->length is being assigned after calling
btrfs_create_block_group_cache. This causes a problem since
set_free_space_tree_thresholds calculates the free-space threshold to
decide if the free-space tree should convert from extents to bitmaps.
The current code calls set_free_space_tree_thresholds with cache->length
being 0, which then makes cache->bitmap_high_thresh zero. This implies
the system will always use bitmap instead of extents, which is not
desired if the block group is not fragmented.
This behavior can be seen by a test that expects to repair systems
with FREE_SPACE_EXTENT and FREE_SPACE_BITMAP, but the current code only
created FREE_SPACE_BITMAP.
[FIX]
Call set_free_space_tree_thresholds after setting cache->length. There
is now a WARN_ON in set_free_space_tree_thresholds to help preventing
the same mistake to happen again in the future.
Link: https://github.com/kdave/btrfs-progs/issues/251
Fixes: 9afc66498a ("btrfs: block-group: refactor how we read one block group item")
CC: stable@vger.kernel.org # 5.8+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.9-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- fix swapfile activation on subvolumes with deleted snapshots
- error value mixup when removing directory entries from tree log
- fix lzo compression level reset after previous level setting
- fix space cache memory leak after transaction abort
- fix const function attribute
- more error handling improvements
* tag 'for-5.9-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: detect nocow for swap after snapshot delete
btrfs: check the right error variable in btrfs_del_dir_entries_in_log
btrfs: fix space cache memory leak after transaction abort
btrfs: use the correct const function attribute for btrfs_get_num_csums
btrfs: reset compression level for lzo on remount
btrfs: handle errors from async submission
can_nocow_extent and btrfs_cross_ref_exist both rely on a heuristic for
detecting a must cow condition which is not exactly accurate, but saves
unnecessary tree traversal. The incorrect assumption is that if the
extent was created in a generation smaller than the last snapshot
generation, it must be referenced by that snapshot. That is true, except
the snapshot could have since been deleted, without affecting the last
snapshot generation.
The original patch claimed a performance win from this check, but it
also leads to a bug where you are unable to use a swapfile if you ever
snapshotted the subvolume it's in. Make the check slower and more strict
for the swapon case, without modifying the general cow checks as a
compromise. Turning swap on does not seem to be a particularly
performance sensitive operation, so incurring a possibly unnecessary
btrfs_search_slot seems worthwhile for the added usability.
Note: Until the snapshot is competely cleaned after deletion,
check_committed_refs will still cause the logic to think that cow is
necessary, so the user must until 'btrfs subvolu sync' finished before
activating the swapfile swapon.
CC: stable@vger.kernel.org # 5.4+
Suggested-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
With my new locking code dbench is so much faster that I tripped over a
transaction abort from ENOSPC. This turned out to be because
btrfs_del_dir_entries_in_log was checking for ret == -ENOSPC, but this
function sets err on error, and returns err. So instead of properly
marking the inode as needing a full commit, we were returning -ENOSPC
and aborting in __btrfs_unlink_inode. Fix this by checking the proper
variable so that we return the correct thing in the case of ENOSPC.
The ENOENT needs to be checked, because btrfs_lookup_dir_item_index()
can return -ENOENT if the dir item isn't in the tree log (which would
happen if we hadn't fsync'ed this guy). We actually handle that case in
__btrfs_unlink_inode, so it's an expected error to get back.
Fixes: 4a500fd178 ("Btrfs: Metadata ENOSPC handling for tree log")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add note and comment about ENOENT ]
Signed-off-by: David Sterba <dsterba@suse.com>
If a transaction aborts it can cause a memory leak of the pages array of
a block group's io_ctl structure. The following steps explain how that can
happen:
1) Transaction N is committing, currently in state TRANS_STATE_UNBLOCKED
and it's about to start writing out dirty extent buffers;
2) Transaction N + 1 already started and another task, task A, just called
btrfs_commit_transaction() on it;
3) Block group B was dirtied (extents allocated from it) by transaction
N + 1, so when task A calls btrfs_start_dirty_block_groups(), at the
very beginning of the transaction commit, it starts writeback for the
block group's space cache by calling btrfs_write_out_cache(), which
allocates the pages array for the block group's io_ctl with a call to
io_ctl_init(). Block group A is added to the io_list of transaction
N + 1 by btrfs_start_dirty_block_groups();
4) While transaction N's commit is writing out the extent buffers, it gets
an IO error and aborts transaction N, also setting the file system to
RO mode;
5) Task A has already returned from btrfs_start_dirty_block_groups(), is at
btrfs_commit_transaction() and has set transaction N + 1 state to
TRANS_STATE_COMMIT_START. Immediately after that it checks that the
filesystem was turned to RO mode, due to transaction N's abort, and
jumps to the "cleanup_transaction" label. After that we end up at
btrfs_cleanup_one_transaction() which calls btrfs_cleanup_dirty_bgs().
That helper finds block group B in the transaction's io_list but it
never releases the pages array of the block group's io_ctl, resulting in
a memory leak.
In fact at the point when we are at btrfs_cleanup_dirty_bgs(), the pages
array points to pages that were already released by us at
__btrfs_write_out_cache() through the call to io_ctl_drop_pages(). We end
up freeing the pages array only after waiting for the ordered extent to
complete through btrfs_wait_cache_io(), which calls io_ctl_free() to do
that. But in the transaction abort case we don't wait for the space cache's
ordered extent to complete through a call to btrfs_wait_cache_io(), so
that's why we end up with a memory leak - we wait for the ordered extent
to complete indirectly by shutting down the work queues and waiting for
any jobs in them to complete before returning from close_ctree().
We can solve the leak simply by freeing the pages array right after
releasing the pages (with the call to io_ctl_drop_pages()) at
__btrfs_write_out_cache(), since we will never use it anymore after that
and the pages array points to already released pages at that point, which
is currently not a problem since no one will use it after that, but not a
good practice anyway since it can easily lead to use-after-free issues.
So fix this by freeing the pages array right after releasing the pages at
__btrfs_write_out_cache().
This issue can often be reproduced with test case generic/475 from fstests
and kmemleak can detect it and reports it with the following trace:
unreferenced object 0xffff9bbf009fa600 (size 512):
comm "fsstress", pid 38807, jiffies 4298504428 (age 22.028s)
hex dump (first 32 bytes):
00 a0 7c 4d 3d ed ff ff 40 a0 7c 4d 3d ed ff ff ..|M=...@.|M=...
80 a0 7c 4d 3d ed ff ff c0 a0 7c 4d 3d ed ff ff ..|M=.....|M=...
backtrace:
[<00000000f4b5cfe2>] __kmalloc+0x1a8/0x3e0
[<0000000028665e7f>] io_ctl_init+0xa7/0x120 [btrfs]
[<00000000a1f95b2d>] __btrfs_write_out_cache+0x86/0x4a0 [btrfs]
[<00000000207ea1b0>] btrfs_write_out_cache+0x7f/0xf0 [btrfs]
[<00000000af21f534>] btrfs_start_dirty_block_groups+0x27b/0x580 [btrfs]
[<00000000c3c23d44>] btrfs_commit_transaction+0xa6f/0xe70 [btrfs]
[<000000009588930c>] create_subvol+0x581/0x9a0 [btrfs]
[<000000009ef2fd7f>] btrfs_mksubvol+0x3fb/0x4a0 [btrfs]
[<00000000474e5187>] __btrfs_ioctl_snap_create+0x119/0x1a0 [btrfs]
[<00000000708ee349>] btrfs_ioctl_snap_create_v2+0xb0/0xf0 [btrfs]
[<00000000ea60106f>] btrfs_ioctl+0x12c/0x3130 [btrfs]
[<000000005c923d6d>] __x64_sys_ioctl+0x83/0xb0
[<0000000043ace2c9>] do_syscall_64+0x33/0x80
[<00000000904efbce>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
