Unlike previous method that tries to commit transaction inside
qgroup_reserve(), this time we will try to commit transaction using
fs_info->transaction_kthread to avoid nested transaction and no need to
worry about locking context.

Since it's an asynchronous function call and we won't wait for
transaction commit, unlike previous method, we must call it before we
hit the qgroup limit.

So this patch will use the ratio and size of qgroup meta_pertrans
reservation as indicator to check if we should trigger a transaction
commit.  (meta_prealloc won't be cleaned in transaction committ, it's
useless anyway)
Signed-off-by: NQu Wenruo <wqu@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Remove GPL boilerplate text (long, short, one-line) and keep the rest,
ie. personal, company or original source copyright statements. Add the
SPDX header.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Btrfs uses 2 different methods to reseve metadata qgroup space.

1) Reserve at btrfs_start_transaction() time
   This is quite straightforward, caller will use the trans handler
   allocated to modify b-trees.

   In this case, reserved metadata should be kept until qgroup numbers
   are updated.

2) Reserve by using block_rsv first, and later btrfs_join_transaction()
   This is more complicated, caller will reserve space using block_rsv
   first, and then later call btrfs_join_transaction() to get a trans
   handle.

   In this case, before we modify trees, the reserved space can be
   modified on demand, and after btrfs_join_transaction(), such reserved
   space should also be kept until qgroup numbers are updated.

Since these two types behave differently, split the original "META"
reservation type into 2 sub-types:

  META_PERTRANS:
    For above case 1)

  META_PREALLOC:
    For reservations that happened before btrfs_join_transaction() of
    case 2)

NOTE: This patch will only convert existing qgroup meta reservation
callers according to its situation, not ensuring all callers are at
correct timing.
Such fix will be added in later patches.
Signed-off-by: NQu Wenruo <wqu@suse.com>
[ update comments ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

It's provided by the transaction handle.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

It's provided by the transaction handle.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

It's provided by the transaction handle.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Since userspace transaction have been removed we no longer have use
for this field so delete it.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Now that the userspace transaction ioctls have been removed,
TRANS_USERSPACE is no longer used hence we can remove it.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

btrfs: qgroup: Fix root item corruption when multiple same source snapshots are created with quota enabled

When multiple pending snapshots referring to the same source subvolume
are executed, enabled quota will cause root item corruption, where root
items are using old bytenr (no backref in extent tree).

This can be triggered by fstests btrfs/152.

The cause is when source subvolume is still dirty, extra commit
(simplied transaction commit) of qgroup_account_snapshot() can skip
dirty roots not recorded in current transaction, making root item of
source subvolume not updated.

Fix it by forcing recording source subvolume in current transaction
before qgroup sub-transaction commit.
Reported-by: NJustin Maggard <jmaggard@netgear.com>
Signed-off-by: NQu Wenruo <wqu@suse.com>
Reviewed-by: NFilipe Manana <fdmanana@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Even though btrfs_start_dirty_block_groups is fairly in the beginning of
btrfs_commit_transaction outside of the critical section defined by the
transaction states it can only be run by a single comitter. In other
words it defines its own critical section thanks to the
BTRFS_TRANS_DIRTY_BG run flag and ro_block_group_mutex. However, its
error handling is outside of this critical section which is a bit
counter-intuitive. So move the error handling righ after the function is
executed and let the sole runner of dirty block groups handle the return
value. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We already pass btrfs_trans_handle which contains a reference to the
fs_info so use that. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We already pass the btrfs_transaction which references fs_info so no
need to pass the later as an argument. Also use the opportunity to
shorten transaction->trans. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We already pass the trans handle which has a reference to fs_info to
create_pending_snapshot so we can refer to it directly. Doing this
obviates the need to pass the fs_info to create_pending_snapshots as
well. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We already have the fs_info from the passed transaction so use it
directly. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The only thing the passed root is used for is:
1. get a reference to the fs_info and to
2. call trace_btrfs_transaction_commit.

We can achieve 1) by simply referring to the fs_info from passed trans
object. As far as 2) is concerned cleanup_transaction is called from
only one place and the 'root' argument passed is the one from the trans
handle. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We already pass a transaction handle which refrences the fs_info so
we can grab it from there. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We already pass the transaction handle which has a reference to the
fs_info. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We already pass the transaction which has a reference to the fs_info,
so use that. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

It can be referenced from the passed transaction so no point in passing
it as a function argument. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

It can be referenced from the passed transaciton so no point in
passing it as function argument. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All current callers of this function just get a reference to the
trans->fs_info member and pass it as the second argument. Collapse this
into the function itself. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

btrfs_write_and_wait_transaction is essentially a wrapper of
btrfs_write_and_wait_marked_extents with the addition of calling
clear_btree_io_tree. Having the code split doesn't really bring any
benefit. Open code the later into the former and add proper
documentation header.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ reformat comment ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This function is only ever used in __btrfs_end_transaction and
btrfs_commit_transaction so there is no need to export it via header.
Let's move it closer to where it's used, make it static and remove it
from the header. No functional changes.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Commit 0e8c36a9 ("Btrfs: fix lots of orphan inodes when the space
is not enough") changed the way transaction reservation is made in
btrfs_evict_node and as a result this function became unused. This has
been the status quo for 5 years in which time no one noticed, so I'd
say it's safe to assume it's unlikely it will ever be used again.

Historical note: there were more attempts to remove the function, the
reasoning was missing and only based on some static analysis tool
reports. Other reason for rejection was that there seemed to be
connection to BTRFS_RESERVE_FLUSH_LIMIT and that would need to be
removeed to. This was not correct so removing the function is all we can
do.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
[ add the note ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This reverts commit 3c181c12.

The offending patch was merged in 4.16-rc4 and was promptly applied to
stable kernels 4.14.25 and 4.15.8.

The patch causes a corruption in several superblock items on big-endian
machines because of messed up endianity conversions. The damage is
manually repairable. A filesystem cannot be mounted again after it has
been unmounted once.

We do a full revert and not a fixup so stable can pick that patch ASAP.

Fixes: 3c181c12 ("btrfs: use proper endianness accessors for super_copy")
Link: https://lkml.kernel.org/r/1521139304@msgid.manchmal.in-ulm.de
CC: stable@vger.kernel.org # 4.14+
Reported-by: NChristoph Biedl <linux-kernel.bfrz@manchmal.in-ulm.de>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The fs_info::super_copy is a byte copy of the on-disk structure and all
members must use the accessor macros/functions to obtain the right
value.  This was missing in update_super_roots and in sysfs readers.

Moving between opposite endianness hosts will report bogus numbers in
sysfs, and mount may fail as the root will not be restored correctly. If
the filesystem is always used on a same endian host, this will not be a
problem.

Fix this by using the btrfs_set_super...() functions to set
fs_info::super_copy values, and for the sysfs, use the cached
fs_info::nodesize/sectorsize values.

CC: stable@vger.kernel.org
Fixes: df93589a ("btrfs: export more from FS_INFO to sysfs")
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

No functional change rearrange the mutex_unlock.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
[ edit subject ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The use_count is a reference counter, we can use the refcount_t type,
though we don't use the atomicity. This is not a performance critical
code and we could catch the underflows. The type is changed from long,
but the number of references will fit an int.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All callers use GFP_NOFS, we don't have to pass it as an argument. The
built-in tests pass GFP_KERNEL, but they run only at module load time
and NOFS works there as well.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We're holding the sb_start_intwrite lock at this point, and doing async
filemap_flush of the inodes will result in a deadlock if we freeze the
fs during this operation.  This is because we could do a
btrfs_join_transaction() in the thread we are waiting on which would
block at sb_start_intwrite, and thus deadlock.  Using
writeback_inodes_sb() side steps the problem by not introducing all of
these extra locking dependencies.
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We were only doing btrfs_check_space_for_delayed_refs() if the metadata
space was full, ie we couldn't allocate chunks.  This assumes we'll be
able to allocate chunks during transaction commit, but since nothing
does a LIMIT flush during the transaction commit this won't actually
happen unless we happen to run shy of actual space.  We already take
into account a full fs in btrfs_check_space_for_delayed_refs() so just
kill this extra check to make sure we're ending the transaction when we
need to.
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We have started plug in btrfs_write_and_wait_marked_extents() but the
generated IOs actually go to device's schedule IO list where the work
is doing in another task, thus the started plug doesn't make any
sense.

And since we wait for IOs immediately after writing meta blocks, it's
the same case as writing log tree, doing sync submit can merge more
IOs.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Dave Jones hit a WARN_ON(nr < 0) in btrfs_wait_ordered_roots() with
v4.12-rc6.  This was because commit 70e7af24 made it possible for
calc_reclaim_items_nr() to return a negative number.  It's not really a
bug in that commit, it just didn't go far enough down the stack to find
all the possible 64->32 bit overflows.

This switches calc_reclaim_items_nr() to return a u64 and changes everyone
that uses the results of that math to u64 as well.
Reported-by: NDave Jones <davej@codemonkey.org.uk>
Fixes: 70e7af24 ("Btrfs: fix delalloc accounting leak caused by u32 overflow")
Signed-off-by: NChris Mason <clm@fb.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Quite a lot of qgroup corruption happens due to wrong time of calling
btrfs_qgroup_prepare_account_extents().

Since the safest time is to call it just before
btrfs_qgroup_account_extents(), there is no need to separate these 2
functions.

Merging them will make code cleaner and less bug prone.
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
[ changelog and comment adjustments ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We can keep the state among the other fs_info flags, there's no reason
why fs_frozen would need to be separate.
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Observing the number of slab objects of btrfs_transaction, there's just
one active on an almost quiescent filesystem, and the number of objects
goes to about ten when sync is in progress. Then the nubmer goes down to
1.  This matches the expectations of the transaction lifetime.

For such use the separate slab cache is not justified, as we do not
reuse objects frequently. For the shortlived transaction, the generic
slab (size 512) should be ok. We can optimistically expect that the 512
slabs are not all used (fragmentation) and there are free slots to take
when we do the allocation, compared to potentially allocating a whole new
page for the separate slab.

We'll lose the stats about the object use, which could be added later if
we really need them.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

For extent_io tree's we have carried the address_mapping of the inode
around in the io tree in order to pull the inode back out for calling
into various tree ops hooks.  This works fine when everything that has
an extent_io_tree has an inode.  But we are going to remove the
btree_inode, so we need to change this.  Instead just have a generic
void * for private data that we can initialize with, and have all the
tree ops use that instead.  This had a lot of cascading changes but
should be relatively straightforward.
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Reviewed-by: NChandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ minor reordering of the callback prototypes ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

[BUG]
The easist way to reproduce the bug is:
------
 # mkfs.btrfs -f $dev -n 16K
 # mount $dev $mnt -o inode_cache
 # btrfs quota enable $mnt
 # btrfs quota rescan -w $mnt
 # btrfs qgroup show $mnt
qgroupid         rfer         excl
--------         ----         ----
0/5          32.00KiB     32.00KiB
             ^^ Twice the correct value
------

And fstests/btrfs qgroup test group can easily detect them with
inode_cache mount option.
Although some of them are false alerts since old test cases are using
fixed golden output.
While new test cases will use "btrfs check" to detect qgroup mismatch.

[CAUSE]
Inode_cache mount option will make commit_fs_roots() to call
btrfs_save_ino_cache() to update fs/subvol trees, and generate new
delayed refs.

However we call btrfs_qgroup_prepare_account_extents() too early, before
commit_fs_roots().
This makes the "old_roots" for newly generated extents are always NULL.
For freeing extent case, this makes both new_roots and old_roots to be
empty, while correct old_roots should not be empty.
This causing qgroup numbers not decreased correctly.

[FIX]
Modify the timing of calling btrfs_qgroup_prepare_account_extents() to
just before btrfs_qgroup_account_extents(), and add needed delayed_refs
handler.
So qgroup can handle inode_map mount options correctly.
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The members have been effectively unused since "Btrfs: rework qgroup
accounting" (fcebe456), there's no substitute for
assert_qgroups_uptodate so it's removed as well.
Reviewed-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>