Commit Graph

7677 Commits

Author SHA1 Message Date
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
Nikolay Borisov
951e05a904 btrfs: Remove impossible condition from mergable_maps
We can never have extents marked as EXTENT_MAP_DELALLOC since this
value is only ever used by btrfs_get_extent_fiemap. In this case the
extent map is created by btrfs_get_extent_fiemap and is never really
published, this flag is used to return the corresponding userspace one.
Considering this, it's pointless having a check for EXTENT_MAP_DELALLOC
in mergable_maps. Just remove it.

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 14:13:21 +01:00
Filipe Manana
d00c2d9c76 Btrfs: do not overwrite error return value in the balance ioctl
If the call to btrfs_balance() failed we would overwrite the error
returned to user space with -EFAULT if the call to copy_to_user() failed
as well. Fix that by calling copy_to_user() only if btrfs_balance()
returned success or was canceled.

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
Filipe Manana
d3a53286c1 Btrfs: do not overwrite error return value in the device replace ioctl
If the call to btrfs_dev_replace_by_ioctl() failed we would overwrite the
error returned to user space with -EFAULT if the call to copy_to_user()
failed as well. Fix that by calling copy_to_user() only if no error
happened before or a device replace operation was canceled.

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 14:13:20 +01:00
Filipe Manana
0f39b60563 Btrfs: remove redundant check for swapfiles when reflinking
Checking if either of the inodes corresponds to a swapfile is already
performed by generic_remap_file_range_prep(), so we do not need to do
it in the btrfs clone and deduplication functions.

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 14:13:20 +01:00
Nikolay Borisov
420829d8ea btrfs: Refactor shrink_delalloc
Add a couple of comments regarding the logic flow in shrink_delalloc.
Then, cease using max_reclaim as a temporary variable when calculating
nr_pages. Finally give max_reclaim a more becoming name, which
uneqivocally shows at what this variable really holds. No functional
changes.

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 14:13:20 +01:00
Nikolay Borisov
4546d17874 btrfs: Document logic regarding inode in async_cow_submit
Add a comment explaining when ->inode could be NULL and why we always
perform the ->async_delalloc_pages modification.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:20 +01:00
Nikolay Borisov
a1d64ba609 btrfs: Remove WARN_ON in btrfs_alloc_delalloc_work
It can never trigger since before calling alloc_delalloc_work we have
called igrab in start_delalloc_inodes.

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 14:13:19 +01:00
Nikolay Borisov
bd4691a0e8 btrfs: Use ihold instead of igrab in cow_file_range_async
ihold is supposed to be used when the caller already has a reference to
the inode. In the case of cow_file_range_async this invariants holds,
since the 3 call chains leading to this function all take a reference:

btrfs_writepage  <--- does igrab
 extent_write_full_page
  __extent_writepage
   writepage_delalloc
     btrfs_run_delalloc_range
      cow_file_range_async

extent_write_cache_pages <--- does igrab
 __extent_writepage (same callchain as above)

and

submit_compressed_extents <-- already called from async CoW submit path,
			      which would have done ihold.
 extent_write_locked_range
  __extent_writepage

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:19 +01:00
Nikolay Borisov
62b3762271 btrfs: Remove isize local variable in compress_file_range
It's used only once so just inline the call to i_size_read. The
semantics regarding the inode size are not changed, the pages in the
range are locked and i_size cannot change between the time it was set
and used.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
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 14:13:19 +01:00
Nikolay Borisov
532425ff9e btrfs: Remove inode argument from async_cow_submit
We already pass the async_cow struct that holds a reference to the
inode. Exploit this fact and remove the extra inode argument. No
functional changes.

Reviewed-by: Anand Jain <anand.jain@oracle.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 14:13:18 +01:00
YueHaibing
aa704d4e75 btrfs: remove set but not used variable 'num_pages'
Fixes gcc '-Wunused-but-set-variable' warning:

fs/btrfs/ioctl.c: In function 'btrfs_extent_same':
fs/btrfs/ioctl.c:3260:6: warning:
 variable 'num_pages' set but not used [-Wunused-but-set-variable]

It not used any more since commit 9ee8234e6220 ("Btrfs: use
generic_remap_file_range_prep() for cloning and deduplication")

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:18 +01:00
Nikolay Borisov
02950af4e3 btrfs: Remove redundant assignment in btrfs_get_extent_fiemap
hole_len is only used if the hole falls within the requested range. Make
that explicitly clear by only assigning in the corresponding branch.

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 14:13:18 +01:00
Nikolay Borisov
f3714ef479 btrfs: Refactor btrfs_get_extent_fiemap
Make btrfs_get_extent_fiemap a bit more friendly. First step is to
rename the closely related, yet arbitrary named
range_start/found_end/found variables. They define the delalloc range
that is found in case a real extent wasn't found. Subsequently remove
an unnecessary check for hole_em since it's guaranteed to be set i.e the
check is always true. Top it off by giving all comments a refresh.

No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ reformatted a few more comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:18 +01:00
Nikolay Borisov
4ab47a8d9c btrfs: Remove unused arguments from btrfs_get_extent_fiemap
This function is a simple wrapper over btrfs_get_extent that returns
either:

a) A real extent in the passed range or
b) Adjusted extent based on whether delalloc bytes are found backing up
   a hole.

To support these semantics it doesn't need the page/pg_offset/create
arguments which are passed to btrfs_get_extent in case an extent is to
be created. So simplify the function by removing the unused arguments.
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 14:13:17 +01:00
Filipe Manana
a087349066 Btrfs: setup a nofs context for memory allocation at __btrfs_set_acl
We are holding a transaction handle when setting an acl, therefore we can
not allocate the xattr value buffer using GFP_KERNEL, as we could deadlock
if reclaim is triggered by the allocation, therefore setup a nofs context.

Fixes: 39a27ec100 ("btrfs: use GFP_KERNEL for xattr and acl allocations")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
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 14:13:17 +01:00
Filipe Manana
b89f6d1fcb Btrfs: setup a nofs context for memory allocation at btrfs_create_tree()
We are holding a transaction handle when creating a tree, therefore we can
not allocate the root using GFP_KERNEL, as we could deadlock if reclaim is
triggered by the allocation, therefore setup a nofs context.

Fixes: 74e4d82757 ("btrfs: let callers of btrfs_alloc_root pass gfp flags")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
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 14:13:16 +01:00
Filipe Manana
eee9957754 Btrfs: do not overwrite error return value in the get device stats ioctl
If the call to btrfs_get_dev_stats() failed we would overwrite the error
returned to user space with -EFAULT if the call to copy_to_user() failed
as well. Fix that by calling copy_to_user() only if btrfs_get_dev_stats()
returned success.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:16 +01:00
Filipe Manana
4fa99b008f Btrfs: do not overwrite error return value in scrub progress ioctl
If the call to btrfs_scrub_progress() failed we would overwrite the error
returned to user space with -EFAULT if the call to copy_to_user() failed
as well. Fix that by calling copy_to_user() only if btrfs_scrub_progress()
returned success.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:16 +01:00
Filipe Manana
06fe39ab15 Btrfs: do not overwrite scrub error with fault error in scrub ioctl
If scrub returned an error and then the copy_to_user() call did not
succeed, we would overwrite the error returned by scrub with -EFAULT.
Fix that by calling copy_to_user() only if btrfs_scrub_dev() returned
success.

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 14:13:15 +01:00
Nikolay Borisov
bc9a8bf79c btrfs: Make first argument of btrfs_run_delalloc_range directly an inode
Since this function is no longer a callback there is no need to have
its first argument obfuscated with a void *. Change it directly to a
pointer to an inode. No functional changes.

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 14:13:15 +01:00
Julia Lawall
9cf10cc195 Btrfs: drop useless LIST_HEAD in merge_reloc_root
Drop LIST_HEAD where the variable it declares is never used.

The uses were removed in 3fd0a5585e ("Btrfs: Metadata ENOSPC
handling for balance"), but not the declaration.

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier x;
@@
- LIST_HEAD(x);
  ... when != x
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:15 +01:00
Linus Torvalds
312b3a93dd for-5.0-rc4-tag
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEE8rQSAMVO+zA4DBdWxWXV+ddtWDsFAlxWtJgACgkQxWXV+ddt
 WDsDow//ZpnyDwQWvSIfF2UUQOPlcBjbHKuBA7rU0wdybW635QYGR0mqnI+1VnMj
 7ssUkeN6N0a2gQzrUG4Y+zpdzOWv2xQ4jKZ9GMOp9gwyzEFyPkcFXOnmM8UfYtVu
 e3fK65e8BZHmTeu0kGKah4Dt1g0t4fUmhsKR4Pfp5YNJC+zuuGTwUW1K/ZQHXJ+3
 kTHc7WP1lsF7wgaZ+Gl+Kvp8fVrHVdygMVTdRBW8QaBgPLa/KExvK62jW+NmCYhj
 7OIkWdew7e8IXc3Ie5IbOomHAv7IgqqgiO9VO9+n0EpyV4UobUgxrgBKJ+0yc1Ya
 eidbKhMslwUE50y00JVm+vw0gwQHkR+hZDn/mRB6xiIeI8tu/yQIJZ6AhYJXoByR
 cu8+SNO5Z5dOZ1f146ZH8lnkr24tuSnkDUhbRDR5pdb4tAHHej2ALzhbfbwbPEpF
 IverYLw5fOMGeRU/mBsjkVadpSZ4S0HVNU85ERdhLtVLK1PSaY2UkUaA+Ii5y7au
 EYDjaGMflmJ8cAVqgtgedEff2n8OKDnzRZlz4IPLI73MVSITGZkM7PmYmYsLm2Bs
 mDPnmyqR8kzcd1RRtSeZTvqOpAIZG+QUOmD2jiKrchmp54Sz0V/HJWRs3aQybD6Q
 ph0yAcbkvgp/ewe5IFgaI0kcyH7zYdL6GtiI2WUE3/8DObgrgsA=
 =E2PP
 -----END PGP SIGNATURE-----

Merge tag 'for-5.0-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - regression fix: transaction commit can run away due to delayed ref
   waiting heuristic, this is not necessary now because of the proper
   reservation mechanism introduced in 5.0

 - regression fix: potential crash due to use-before-check of an ERR_PTR
   return value

 - fix for transaction abort during transaction commit that needs to
   properly clean up pending block groups

 - fix deadlock during b-tree node/leaf splitting, when this happens on
   some of the fundamental trees, we must prevent new tree block
   allocation to re-enter indirectly via the block group flushing path

 - potential memory leak after errors during mount

* tag 'for-5.0-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: On error always free subvol_name in btrfs_mount
  btrfs: clean up pending block groups when transaction commit aborts
  btrfs: fix potential oops in device_list_add
  btrfs: don't end the transaction for delayed refs in throttle
  Btrfs: fix deadlock when allocating tree block during leaf/node split
2019-02-03 08:48:33 -08:00
Eric W. Biederman
532b618bdf btrfs: On error always free subvol_name in btrfs_mount
The subvol_name is allocated in btrfs_parse_subvol_options and is
consumed and freed in mount_subvol.  Add a free to the error paths that
don't call mount_subvol so that it is guaranteed that subvol_name is
freed when an error happens.

Fixes: 312c89fbca ("btrfs: cleanup btrfs_mount() using btrfs_mount_root()")
Cc: stable@vger.kernel.org # v4.19+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-30 18:16:47 +01:00
David Sterba
c7cc64a985 btrfs: clean up pending block groups when transaction commit aborts
The fstests generic/475 stresses transaction aborts and can reveal
space accounting or use-after-free bugs regarding block goups.

In this case the pending block groups that remain linked to the
structures after transaction commit aborts in the middle.

The corrupted slabs lead to failures in following tests, eg. generic/476

  [ 8172.752887] BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
  [ 8172.755799] #PF error: [normal kernel read fault]
  [ 8172.757571] PGD 661ae067 P4D 661ae067 PUD 3db8e067 PMD 0
  [ 8172.759000] Oops: 0000 [#1] PREEMPT SMP
  [ 8172.760209] CPU: 0 PID: 39 Comm: kswapd0 Tainted: G        W         5.0.0-rc2-default #408
  [ 8172.762495] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014
  [ 8172.765772] RIP: 0010:shrink_page_list+0x2f9/0xe90
  [ 8172.770453] RSP: 0018:ffff967f00663b18 EFLAGS: 00010287
  [ 8172.771184] RAX: 0000000000000000 RBX: ffff967f00663c20 RCX: 0000000000000000
  [ 8172.772850] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8c0620ab20e0
  [ 8172.774629] RBP: ffff967f00663dd8 R08: 0000000000000000 R09: 0000000000000000
  [ 8172.776094] R10: ffff8c0620ab22f8 R11: ffff8c063f772688 R12: ffff967f00663b78
  [ 8172.777533] R13: ffff8c063f625600 R14: ffff8c063f625608 R15: dead000000000200
  [ 8172.778886] FS:  0000000000000000(0000) GS:ffff8c063d400000(0000) knlGS:0000000000000000
  [ 8172.780545] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 8172.781787] CR2: 0000000000000058 CR3: 000000004e962000 CR4: 00000000000006f0
  [ 8172.783547] Call Trace:
  [ 8172.784112]  shrink_inactive_list+0x194/0x410
  [ 8172.784747]  shrink_node_memcg.constprop.85+0x3a5/0x6a0
  [ 8172.785472]  shrink_node+0x62/0x1e0
  [ 8172.786011]  balance_pgdat+0x216/0x460
  [ 8172.786577]  kswapd+0xe3/0x4a0
  [ 8172.787085]  ? finish_wait+0x80/0x80
  [ 8172.787795]  ? balance_pgdat+0x460/0x460
  [ 8172.788799]  kthread+0x116/0x130
  [ 8172.789640]  ? kthread_create_on_node+0x60/0x60
  [ 8172.790323]  ret_from_fork+0x24/0x30
  [ 8172.794253] CR2: 0000000000000058

or accounting errors at umount time:

  [ 8159.537251] WARNING: CPU: 2 PID: 19031 at fs/btrfs/extent-tree.c:5987 btrfs_free_block_groups+0x3d5/0x410 [btrfs]
  [ 8159.543325] CPU: 2 PID: 19031 Comm: umount Tainted: G        W         5.0.0-rc2-default #408
  [ 8159.545472] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014
  [ 8159.548155] RIP: 0010:btrfs_free_block_groups+0x3d5/0x410 [btrfs]
  [ 8159.554030] RSP: 0018:ffff967f079cbde8 EFLAGS: 00010206
  [ 8159.555144] RAX: 0000000001000000 RBX: ffff8c06366cf800 RCX: 0000000000000000
  [ 8159.556730] RDX: 0000000000000002 RSI: 0000000000000001 RDI: ffff8c06255ad800
  [ 8159.558279] RBP: ffff8c0637ac0000 R08: 0000000000000001 R09: 0000000000000000
  [ 8159.559797] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8c0637ac0108
  [ 8159.561296] R13: ffff8c0637ac0158 R14: 0000000000000000 R15: dead000000000100
  [ 8159.562852] FS:  00007f7f693b9fc0(0000) GS:ffff8c063d800000(0000) knlGS:0000000000000000
  [ 8159.564839] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 8159.566160] CR2: 00007f7f68fab7b0 CR3: 000000000aec7000 CR4: 00000000000006e0
  [ 8159.567898] Call Trace:
  [ 8159.568597]  close_ctree+0x17f/0x350 [btrfs]
  [ 8159.569628]  generic_shutdown_super+0x64/0x100
  [ 8159.570808]  kill_anon_super+0x14/0x30
  [ 8159.571857]  btrfs_kill_super+0x12/0xa0 [btrfs]
  [ 8159.573063]  deactivate_locked_super+0x29/0x60
  [ 8159.574234]  cleanup_mnt+0x3b/0x70
  [ 8159.575176]  task_work_run+0x98/0xc0
  [ 8159.576177]  exit_to_usermode_loop+0x83/0x90
  [ 8159.577315]  do_syscall_64+0x15b/0x180
  [ 8159.578339]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

This fix is based on 2 Josef's patches that used sideefects of
btrfs_create_pending_block_groups, this fix introduces the helper that
does what we need.

CC: stable@vger.kernel.org # 4.4+
CC: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-30 18:16:47 +01:00
Al Viro
92900e5160 btrfs: fix potential oops in device_list_add
alloc_fs_devices() can return ERR_PTR(-ENOMEM), so dereferencing its
result before the check for IS_ERR() is a bad idea.

Fixes: d1a6300282 ("btrfs: add members to fs_devices to track fsid changes")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-30 18:16:40 +01:00