Commit Graph

7702 Commits

Author SHA1 Message Date
Nikolay Borisov
9a0ec83d57 btrfs: use WARN_ON in a canonical form btrfs_remove_block_group
There is no point in using a construct like 'if (!condition)
WARN_ON(1)'. Use WARN_ON(!condition) directly. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:36 +01:00
Josef Bacik
260e77025f btrfs: reserve extra space during evict
We could generate a lot of delayed refs in evict but never have any left
over space from our block rsv to make up for that fact.  So reserve some
extra space and give it to the transaction so it can be used to refill
the delayed refs rsv every loop through the truncate path.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:35 +01:00
Josef Bacik
8a1bbe1d5c btrfs: be more explicit about allowed flush states
For FLUSH_LIMIT flushers we really can only allocate chunks and flush
delayed inode items, everything else is problematic.  I added a bunch of
new states and it lead to weirdness in the FLUSH_LIMIT case because I
forgot about how it worked.  So instead explicitly declare the states
that are ok for flushing with FLUSH_LIMIT and use that for our state
machine.  Then as we add new things that are safe we can just add them
to this list.

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>
2019-02-25 14:13:35 +01:00
Josef Bacik
5df1136363 btrfs: loop in inode_rsv_refill
With severe fragmentation we can end up with our inode rsv size being
huge during writeout, which would cause us to need to make very large
metadata reservations.

However we may not actually need that much once writeout is complete,
because of the over-reservation for the worst case.

So instead try to make our reservation, and if we couldn't make it
re-calculate our new reservation size and try again.  If our reservation
size doesn't change between tries then we know we are actually out of
space and can error. Flushing that could have been running in parallel
did not make any space.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ rename to calc_refill_bytes, update comment and changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:35 +01:00
Josef Bacik
f91587e415 btrfs: don't enospc all tickets on flush failure
With the introduction of the per-inode block_rsv it became possible to
have really really large reservation requests made because of data
fragmentation.  Since the ticket stuff assumed that we'd always have
relatively small reservation requests it just killed all tickets if we
were unable to satisfy the current request.

However, this is generally not the case anymore.  So fix this logic to
instead see if we had a ticket that we were able to give some
reservation to, and if we were continue the flushing loop again.

Likewise we make the tickets use the space_info_add_old_bytes() method
of returning what reservation they did receive in hopes that it could
satisfy reservations down the line.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:34 +01:00
Josef Bacik
450114fc0d btrfs: don't use global reserve for chunk allocation
We've done this forever because of the voodoo around knowing how much
space we have.  However, we have better ways of doing this now, and on
normal file systems we'll easily have a global reserve of 512MiB, and
since metadata chunks are usually 1GiB that means we'll allocate
metadata chunks more readily.  Instead use the actual used amount when
determining if we need to allocate a chunk or not.

This has a side effect for mixed block group fs'es where we are no
longer allocating enough chunks for the data/metadata requirements.  To
deal with this add a ALLOC_CHUNK_FORCE step to the flushing state
machine.  This will only get used if we've already made a full loop
through the flushing machinery and tried committing the transaction.

If we have then we can try and force a chunk allocation since we likely
need it to make progress.  This resolves issues I was seeing with
the mixed bg tests in xfstests without the new flushing state.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ merged with patch "add ALLOC_CHUNK_FORCE to the flushing code" ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:34 +01:00
Josef Bacik
b78e5616af btrfs: dump block_rsv details when dumping space info
For enospc_debug having the block rsvs is super helpful to see if we've
done something wrong.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:34 +01:00
Josef Bacik
d89dbefb8c btrfs: check if there are free block groups for commit
may_commit_transaction will skip committing the transaction if we don't
have enough pinned space or if we're trying to find space for a SYSTEM
chunk.  However, if we have pending free block groups in this transaction
we still want to commit as we may be able to allocate a chunk to make
our reservation.  So instead of just returning ENOSPC, check if we have
free block groups pending, and if so commit the transaction to allow us
to use that free space.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:33 +01:00
Dennis Zhou
3f93aef535 btrfs: add zstd compression level support
Zstd compression requires different amounts of memory for each level of
compression. The prior patches implemented indirection to allow for each
compression type to manage their workspaces independently. This patch
uses this indirection to implement compression level support for zstd.

To manage the additional memory require, each compression level has its
own queue of workspaces. A global LRU is used to help with reclaim.
Reclaim is done via a timer which provides a mechanism to decrease
memory utilization by keeping only workspaces around that are sized
appropriately. Forward progress is guaranteed by a preallocated max
workspace hidden from the LRU.

When getting a workspace, it uses a bitmap to identify the levels that
are populated and scans up. If it finds a workspace that is greater than
it, it uses it, but does not update the last_used time and the
corresponding place in the LRU. If we hit memory pressure, we sleep on
the max level workspace. We continue to rescan in case we can use a
smaller workspace, but eventually should be able to obtain the max level
workspace or allocate one again should memory pressure subside.

The memory requirement for decompression is the same as level 1, and
therefore can use any of available workspace.

The number of workspaces is bound by an upper limit of the workqueue's
limit which currently is 2 (percpu limit). The reclaim timer is used to
free inactive/improperly sized workspaces and is set to 307s to avoid
colliding with transaction commit (every 30s).

Repeating the experiment from v2 [1], the Silesia corpus was copied to a
btrfs filesystem 10 times and then read back after dropping the caches.
The btrfs filesystem was on an SSD.

Level   Ratio   Compression (MB/s)  Decompression (MB/s)  Memory (KB)
1       2.658        438.47                910.51            780
2       2.744        364.86                886.55           1004
3       2.801        336.33                828.41           1260
4       2.858        286.71                886.55           1260
5       2.916        212.77                556.84           1388
6       2.363        119.82                990.85           1516
7       3.000        154.06                849.30           1516
8       3.011        159.54                875.03           1772
9       3.025        100.51                940.15           1772
10      3.033        118.97                616.26           1772
11      3.036         94.19                802.11           1772
12      3.037         73.45                931.49           1772
13      3.041         55.17                835.26           2284
14      3.087         44.70                716.78           2547
15      3.126         37.30                878.84           2547

[1] https://lore.kernel.org/linux-btrfs/20181031181108.289340-1-terrelln@fb.com/

Cc: Nick Terrell <terrelln@fb.com>
Cc: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:33 +01:00
Dennis Zhou
d3c6ab752c btrfs: make zstd memory requirements monotonic
It is possible based on the level configurations that a higher level
workspace uses less memory than a lower level workspace. In order to
reuse workspaces, this must be made a monotonic relationship. This
precomputes the required memory for each level and enforces the
monotonicity between level and memory required. This is also done
in upstream zstd in [1].

[1] a68b76afef

Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:33 +01:00
Dennis Zhou
e0dc87afcd btrfs: zstd use the passed through level instead of default
Zstd currently only supports the default level of compression. This
patch switches to using the level passed in for btrfs zstd
configuration.

Zstd workspaces now keep track of the requested level as this can differ
from the size of the workspace.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:33 +01:00
Dennis Zhou
d0ab62ce2d btrfs: change set_level() to bound the level passed in
Currently, the only user of set_level() is zlib which sets an internal
workspace parameter. As level is now plumbed into get_workspace(), this
can be handled there rather than separately.

This repurposes set_level() to bound the level passed in so it can be
used when setting the mounts compression level and as well as verifying
the level before getting a workspace. The other benefit is this divides
the meaning of compress(0) and get_workspace(0). The former means we
want to use the default compression level of the compression type. The
latter means we can use any workspace available.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:32 +01:00
Dennis Zhou
7bf4994304 btrfs: plumb level through the compression interface
Zlib compression supports multiple levels, but doesn't require changing
in how a workspace itself is created and managed. Zstd introduces a
different memory requirement such that higher levels of compression
require more memory.

This requires changes in how the alloc()/get() methods work for zstd.
This pach plumbs compression level through the interface as a parameter
in preparation for zstd compression levels.  This gives the compression
types opportunity to create/manage based on the compression level.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:32 +01:00
Dennis Zhou
92ee553036 btrfs: move to function pointers for get/put workspaces
The previous patch added generic helpers for get_workspace() and
put_workspace(). Now, we can migrate ownership of the workspace_manager
to be in the compression type code as the compression code itself
doesn't care beyond being able to get a workspace. The init/cleanup and
get/put methods are abstracted so each compression algorithm can decide
how they want to manage their workspaces.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:32 +01:00
Dennis Zhou
929f4baf93 btrfs: add compression interface in (get/put)_workspace
There are two levels of workspace management. First, alloc()/free()
which are responsible for actually creating and destroy workspaces.
Second, at a higher level, get()/put() which is the compression code
asking for a workspace from a workspace_manager.

The compression code shouldn't really care how it gets a workspace, but
that it got a workspace. This adds get_workspace() and put_workspace()
to be the higher level interface which is responsible for indexing into
the appropriate compression type. It also introduces
btrfs_put_workspace() and btrfs_get_workspace() to be the generic
implementations of the higher interface.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:31 +01:00
Dennis Zhou
1666edabc8 btrfs: add helper methods for workspace manager init and cleanup
Workspace manager init and cleanup code is open coded inside a for loop
over the compression types. This forces each compression type to rely on
the same workspace manager implementation. This patch creates helper
methods that will be the generic implementation for btrfs workspace
management.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:31 +01:00
Dennis Zhou
10b94a51ca btrfs: unify compression ops with workspace_manager
Make the workspace_manager own the interface operations rather than
managing index-paired arrays for the workspace_manager and compression
operations.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:31 +01:00
Dennis Zhou
ca4ac360af btrfs: manage heuristic workspace as index 0
While the heuristic workspaces aren't really compression workspaces,
they use the same interface for managing them. So rather than branching,
let's just handle them once again as the index 0 compression type.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:31 +01:00
Dennis Zhou
acce85de12 btrfs: rename workspaces_list to workspace_manager
This is in preparation for zstd compression levels. As each level will
require different size of workspace, workspaces_list is no longer a
really fitting name.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:30 +01:00
Dennis Zhou
1972708a89 btrfs: add helpers for compression type and level
It is very easy to miss places that rely on a certain bitshifting for
decoding the type_level overloading. Add helpers to do this instead.

Cc: Omar Sandoval <osandov@osandov.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:30 +01:00
Anand Jain
228a73abde btrfs: introduce new ioctl to unregister a btrfs device
Support for a new command that can be used eg. as a command

  $ btrfs device scan --forget [dev]'
(the final name may change though)

to undo the effects of 'btrfs device scan [dev]'. For this purpose
this patch proposes to use ioctl #5 as it was empty and is next to the
SCAN ioctl.

The new ioctl BTRFS_IOC_FORGET_DEV works only on the control device
(/dev/btrfs-control) to unregister one or all devices, devices that are
not mounted.

The argument is struct btrfs_ioctl_vol_args, ::name specifies the device
path. To unregister all device, the path is an empty string.

Again, the devices are removed only if they aren't part of a mounte
filesystem.

This new ioctl provides:

- release of unwanted btrfs_fs_devices and btrfs_devices structures
  from memory if the device is not going to be mounted

- ability to mount filesystem in degraded mode, when one devices is
  corrupted like in split brain raid1

- running test cases which would require reloading the kernel module
  but this is not possible eg. due to mounted filesystem or built-in

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:30 +01:00
Josef Bacik
034f784d7c btrfs: replace cleaner_delayed_iput_mutex with a waitqueue
The throttle path doesn't take cleaner_delayed_iput_mutex, which means
we could think we're done flushing iputs in the data space reservation
path when we could have a throttler doing an iput.  There's no real
reason to serialize the delayed iput flushing, so instead of taking the
cleaner_delayed_iput_mutex whenever we flush the delayed iputs just
replace it with an atomic counter and a waitqueue.  This removes the
short (or long depending on how big the inode is) window where we think
there are no more pending iputs when there really are some.

The waiting is killable as it could be indirectly called from user
operations like fallocate or zero-range. Such call sites should handle
the error but otherwise it's not necessary. Eg. flush_space just needs
to attempt to make space by waiting on iputs.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ add killable comment and changelog parts ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:29 +01:00
Qu Wenruo
3ece54e504 btrfs: Output ENOSPC debug info in inc_block_group_ro
Since inc_block_group_ro() would return -ENOSPC, outputting debug info
for enospc_debug mount option would be helpful to debug some balance
false ENOSPC report.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:29 +01:00
Qu Wenruo
c8f72b98b6 btrfs: qgroup: Remove duplicated trace points for qgroup_rsv_add/release
Inside qgroup_rsv_add/release(), we have trace events
trace_qgroup_update_reserve() to catch reserved space update.

However we still have two manual trace_qgroup_update_reserve() calls
just outside these functions.  Remove these duplicated calls.

Fixes: 64ee4e751a ("btrfs: qgroup: Update trace events to use new separate rsv types")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:28 +01:00
Anders Roxell
2eec5f0042 btrfs: let the assertion expression compile in all configs
A compiler warning (in a patch in development) pointed to a variable
that was used only inside and ASSERT:

  u64 root_objectid = root->root_key.objectid;
  ASSERT(root_objectid == ...);

  fs/btrfs/relocation.c: In function ‘insert_dirty_subv’:
  fs/btrfs/relocation.c:2138:6: warning: unused variable ‘root_objectid’ [-Wunused-variable]
    u64 root_objectid = root->root_key.objectid;
	^~~~~~~~~~~~~

When CONFIG_BRTFS_ASSERT isn't enabled, variable root_objectid isn't used.

Rework the assertion helper by adding a runtime check instead of the
'#ifdef CONFIG_BTRFS_ASSERT #else ...", so the compiler sees the
condition being passed into an inline function after preprocessing.

Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:28 +01:00
David Sterba
766ece54f4 btrfs: merge btrfs_set_lock_blocking_rw with it's caller
The last caller that does not have a fixed value of lock is
btrfs_set_path_blocking, that actually does the same conditional swtich
by the lock type so we can merge the branches together and remove the
helper.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:28 +01:00
David Sterba
970e74d961 btrfs: simplify waiting loop in btrfs_tree_lock
Currently, the number of readers and writers is checked and in case
there are any, wait and redo the locks. There's some duplication
before the branches go back to again label, eg. calling wait_event on
blocking_readers twice.

The sequence is transformed

loop:
* wait for readers
* wait for writers
* write_lock
* check readers, unlock and wait for readers, loop
* check writers, unlock and wait for writers, loop

The new sequence is not exactly the same due to the simplification, for
readers it's slightly faster. For the writers, original code does

* wait for writers
* (loop) wait for readers
*        wait for writers -- again

while the new goes directly to the reader check. This should behave the
same on a contended lock with multiple writers and readers, but can
reduce number of times we're waiting on something.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:28 +01:00
David Sterba
8bead25820 btrfs: open code now trivial btrfs_set_lock_blocking
btrfs_set_lock_blocking is now only a simple wrapper around
btrfs_set_lock_blocking_write. The name does not bring any semantic
value that could not be inferred from the new function so there's no
point keeping it.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:27 +01:00
David Sterba
300aa896e1 btrfs: replace btrfs_set_lock_blocking_rw with appropriate helpers
We can use the right helper where the lock type is a fixed parameter.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:27 +01:00
David Sterba
aa12c02778 btrfs: split btrfs_clear_lock_blocking_rw to read and write helpers
There are many callers that hardcode the desired lock type so we can
avoid the switch and call them directly. Split the current function to
two. There are no remaining users of btrfs_clear_lock_blocking_rw so
it's removed.  The call sites will be converted in followup patches.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:27 +01:00
David Sterba
b95be2d9fb btrfs: split btrfs_set_lock_blocking_rw to read and write helpers
There are many callers that hardcode the desired lock type so we can
avoid the switch and call them directly. Split the current function to
two but leave a helper that still takes the variable lock type to make
current code compile.  The call sites will be converted in followup
patches.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:27 +01:00
Qu Wenruo
9627736b75 btrfs: qgroup: Cleanup old subtree swap code
Since it's replaced by new delayed subtree swap code, remove the
original code.

The cleanup is small since most of its core function is still used by
delayed subtree swap trace.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:26 +01:00
Qu Wenruo
f616f5cd9d btrfs: qgroup: Use delayed subtree rescan for balance
Before this patch, qgroup code traces the whole subtree of subvolume and
reloc trees unconditionally.

This makes qgroup numbers consistent, but it could cause tons of
unnecessary extent tracing, which causes a lot of overhead.

However for subtree swap of balance, just swap both subtrees because
they contain the same contents and tree structure, so qgroup numbers
won't change.

It's the race window between subtree swap and transaction commit could
cause qgroup number change.

This patch will delay the qgroup subtree scan until COW happens for the
subtree root.

So if there is no other operations for the fs, balance won't cause extra
qgroup overhead. (best case scenario)
Depending on the workload, most of the subtree scan can still be
avoided.

Only for worst case scenario, it will fall back to old subtree swap
overhead. (scan all swapped subtrees)

[[Benchmark]]
Hardware:
	VM 4G vRAM, 8 vCPUs,
	disk is using 'unsafe' cache mode,
	backing device is SAMSUNG 850 evo SSD.
	Host has 16G ram.

Mkfs parameter:
	--nodesize 4K (To bump up tree size)

Initial subvolume contents:
	4G data copied from /usr and /lib.
	(With enough regular small files)

Snapshots:
	16 snapshots of the original subvolume.
	each snapshot has 3 random files modified.

balance parameter:
	-m

So the content should be pretty similar to a real world root fs layout.

And after file system population, there is no other activity, so it
should be the best case scenario.

                     | v4.20-rc1            | w/ patchset    | diff
-----------------------------------------------------------------------
relocated extents    | 22615                | 22457          | -0.1%
qgroup dirty extents | 163457               | 121606         | -25.6%
time (sys)           | 22.884s              | 18.842s        | -17.6%
time (real)          | 27.724s              | 22.884s        | -17.5%

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:26 +01:00
Qu Wenruo
370a11b811 btrfs: qgroup: Introduce per-root swapped blocks infrastructure
To allow delayed subtree swap rescan, btrfs needs to record per-root
information about which tree blocks get swapped.  This patch introduces
the required infrastructure.

The designed workflow will be:

1) Record the subtree root block that gets swapped.

   During subtree swap:
   O = Old tree blocks
   N = New tree blocks
         reloc tree                         subvolume tree X
            Root                               Root
           /    \                             /    \
         NA     OB                          OA      OB
       /  |     |  \                      /  |      |  \
     NC  ND     OE  OF                   OC  OD     OE  OF

  In this case, NA and OA are going to be swapped, record (NA, OA) into
  subvolume tree X.

2) After subtree swap.
         reloc tree                         subvolume tree X
            Root                               Root
           /    \                             /    \
         OA     OB                          NA      OB
       /  |     |  \                      /  |      |  \
     OC  OD     OE  OF                   NC  ND     OE  OF

3a) COW happens for OB
    If we are going to COW tree block OB, we check OB's bytenr against
    tree X's swapped_blocks structure.
    If it doesn't fit any, nothing will happen.

3b) COW happens for NA
    Check NA's bytenr against tree X's swapped_blocks, and get a hit.
    Then we do subtree scan on both subtrees OA and NA.
    Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND).

    Then no matter what we do to subvolume tree X, qgroup numbers will
    still be correct.
    Then NA's record gets removed from X's swapped_blocks.

4)  Transaction commit
    Any record in X's swapped_blocks gets removed, since there is no
    modification to swapped subtrees, no need to trigger heavy qgroup
    subtree rescan for them.

This will introduce 128 bytes overhead for each btrfs_root even qgroup
is not enabled. This is to reduce memory allocations and potential
failures.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:26 +01:00
Qu Wenruo
5aea1a4fcf btrfs: qgroup: Refactor btrfs_qgroup_trace_subtree_swap
Refactor btrfs_qgroup_trace_subtree_swap() into
qgroup_trace_subtree_swap(), which only needs two extent buffer and some
other bool to control the behavior.

This provides the basis for later delayed subtree scan work.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:26 +01:00
Qu Wenruo
d2311e6985 btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots
Relocation code will drop btrfs_root::reloc_root as soon as
merge_reloc_root() finishes.

However later qgroup code will need to access btrfs_root::reloc_root
after merge_reloc_root() for delayed subtree rescan.

So alter the timming of resetting btrfs_root:::reloc_root, make it
happens after transaction commit.

With this patch, we will introduce a new btrfs_root::state,
BTRFS_ROOT_DEAD_RELOC_TREE, to info part of btrfs_root::reloc_tree user
that although btrfs_root::reloc_tree is still non-NULL, but still it's
not used any more.

The lifespan of btrfs_root::reloc tree will become:
          Old behavior            |              New
------------------------------------------------------------------------
btrfs_init_reloc_root()      ---  | btrfs_init_reloc_root()      ---
  set reloc_root              |   |   set reloc_root              |
                              |   |                               |
                              |   |                               |
merge_reloc_root()            |   | merge_reloc_root()            |
|- btrfs_update_reloc_root() ---  | |- btrfs_update_reloc_root() -+-
     clear btrfs_root::reloc_root |      set ROOT_DEAD_RELOC_TREE |
                                  |      record root into dirty   |
                                  |      roots rbtree             |
                                  |                               |
                                  | reloc_block_group() Or        |
                                  | btrfs_recover_relocation()    |
                                  | | After transaction commit    |
                                  | |- clean_dirty_subvols()     ---
                                  |     clear btrfs_root::reloc_root

During ROOT_DEAD_RELOC_TREE set lifespan, the only user of
btrfs_root::reloc_tree should be qgroup.

Since reloc root needs a longer life-span, this patch will also delay
btrfs_drop_snapshot() call.
Now btrfs_drop_snapshot() is called in clean_dirty_subvols().

This patch will increase the size of btrfs_root by 16 bytes.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:25 +01:00
Josef Bacik
119e80df7d btrfs: call btrfs_create_pending_block_groups unconditionally
The first thing we do is loop through the list, this

if (!list_empty())
	btrfs_create_pending_block_groups();

thing is just wasted space.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:25 +01:00
Josef Bacik
fa781cea3d btrfs: make btrfs_destroy_delayed_refs use btrfs_delete_ref_head
Instead of open coding this stuff use the helper instead.

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>
2019-02-25 14:13:25 +01:00
Josef Bacik
3069bd2669 btrfs: make btrfs_destroy_delayed_refs use btrfs_delayed_ref_lock
We have this open coded in btrfs_destroy_delayed_refs, use the helper
instead.

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>
2019-02-25 14:13:25 +01:00
Anand Jain
d1e1442065 btrfs: scrub: print messages when started or finished
The kernel log messages help debugging and audit, add them for scrub

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:24 +01:00
David Sterba
ce3ded1061 btrfs: simplify workqueue name when allocating
The workqueue name is constructed from a format string but the prefix
does not need to be set by %s.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:24 +01:00
Anand Jain
09ba3bc9dd btrfs: merge btrfs_find_device and find_device
Both btrfs_find_device() and find_device() does the same thing except
that the latter does not take the seed device onto account in the device
scanning context. We can merge them.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:24 +01:00
Anand Jain
70bc7088aa btrfs: refactor btrfs_free_stale_devices() to get return value
Preparatory patch to add ioctl that allows to forget a device (ie.
reverse of scan).

Refactors btrfs_free_stale_devices() to obtain return status. As this
function can fail if it can't find the given path (returns -ENOENT) or
trying to delete a mounted device (returns -EBUSY).

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:23 +01:00
Anand Jain
e4319cd9ca btrfs: refactor btrfs_find_device() take fs_devices as argument
btrfs_find_device() accepts fs_info as an argument and retrieves
fs_devices from fs_info.

Instead use fs_devices, so that this function can be used in non-mount
(during device scanning) context as well.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:23 +01:00
Anand Jain
6e927cebe2 btrfs: cleanup btrfs_find_device_by_devspec()
btrfs_find_device_by_devspec() finds the device by @devid or by
@device_path. This patch makes code flow easy to read by open coding the
else part and renames devpath to device_path.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:23 +01:00
Anand Jain
d95a830c78 btrfs: merge btrfs_find_device_missing_or_by_path() into parent
btrfs_find_device_missing_or_by_path() is relatively small function, and
its only parent btrfs_find_device_by_devspec() is small as well. Besides
there are a number of find_device functions. Merge
btrfs_find_device_missing_or_by_path() into its parent.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:22 +01:00
Nikolay Borisov
02a033df7a btrfs: Remove not_found_em label from btrfs_get_extent
In order to avoid duplicating init code for em there is an additional
label, not_found_em, which is used to only set ->block_start. The only
case when it will be used is if the extent we are adding overlaps with
an existing extent. Make that case more obvious by:

 1. Adding a comment hinting at what's going on
 2. Assigning EXTENT_MAP_HOLE and directly going to insert.

 No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:22 +01:00
Nikolay Borisov
b8eeab7fce btrfs: Consolidate retval checking of core btree functions
Core btree functions in btrfs generally return 0 when an item is found,
1 in case the sought item cannot be found and <0 when an error happens.
Consolidate the checks for those conditions in one 'if () {} else if ()
{}' construct rather than 2 separate 'if () {}' statements. This
emphasizes that the handling code pertains to a single function. No
functional changes.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:22 +01:00
Nikolay Borisov
694c12ed9d btrfs: Rename found_type to extent_type in btrfs_get_extent
found_type really holds the type of extent and is guaranteed to to have
a value between [0, 2]. The only time it can contain anything different
is if btrfs_lookup_file_extent returned a positive value and the
previous item is different than an extent. Avoid this situation by
simply checking found_key.type rather than assigning the item type to
found_type intermittently. Also make the variable an u8 to reduce stack
usage. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:22 +01:00
Filipe Manana
500710d3b8 Btrfs: move duplicated nodatasum check into common reflink/dedupe helper
Move the check that verifies if both inodes have checksums disabled or
both have them enabled, from the clone and deduplication functions into
the new common helper btrfs_remap_file_range_prep().

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:21 +01:00