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902415 commits

Author SHA1 Message Date
Johannes Thumshirn
fd8efa818c btrfs: simplify error handling in __btrfs_write_out_cache()
The error cleanup gotos in __btrfs_write_out_cache() needlessly jump
back making the code less readable then needed.  Flatten them out so no
back-jump is necessary and the read flow is uninterrupted.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:43 +01:00
Johannes Thumshirn
1afb648e94 btrfs: use standard debug config option to enable free-space-cache debug prints
free-space-cache.c has it's own set of DEBUG ifdefs which need to be
turned on instead of the global CONFIG_BTRFS_DEBUG to print debug
messages about failed block-group writes.

Switch this over to CONFIG_BTRFS_DEBUG so we always see these messages
when running a debug kernel.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:43 +01:00
Johannes Thumshirn
7a195f6db9 btrfs: make the uptodate argument of io_ctl_add_pages() boolean
Make the uptodate argument of io_ctl_add_pages() boolean.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:43 +01:00
Johannes Thumshirn
831fa14f1e btrfs: use inode from io_ctl in io_ctl_prepare_pages
io_ctl_prepare_pages() gets a 'struct btrfs_io_ctl' as well as a 'struct
inode', but btrfs_io_ctl::inode points to the same struct inode as this is
assgined in io_ctl_init().

Use the inode form io_ctl to reduce the arguments of io_ctl_prepare_pages.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:43 +01:00
Marcos Paulo de Souza
949964c928 btrfs: add new BTRFS_IOC_SNAP_DESTROY_V2 ioctl
This ioctl will be responsible for deleting a subvolume using its id.
This can be used when a system has a file system mounted from a
subvolume, rather than the root file system, like below:

/
@subvol1/
@subvol2/
@subvol_default/

If only @subvol_default is mounted, we have no path to reach @subvol1
and @subvol2, thus no way to delete them. Current subvolume delete ioctl
takes a file handle point as argument, and if @subvol_default is
mounted, we can't reach @subvol1 and @subvol2 from the same mount point.

This patch introduces a new ioctl BTRFS_IOC_SNAP_DESTROY_V2 that takes
the extended structure with flags to allow to delete subvolume using
subvolid.

Now, we can use this new ioctl specifying the subvolume id and refer to
the same mount point. It doesn't matter which subvolume was mounted,
since we can reach to the desired one using the subvolume id, and then
delete it.

The full path to the subvolume id is resolved internally and access is
verified as if the subvolume was accessed by path.

The volume args v2 structure is extended to use the existing union for
subvolume id specification, that's valid in case the
BTRFS_SUBVOL_SPEC_BY_ID is set.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:42 +01:00
Marcos Paulo de Souza
c0c907a47d btrfs: export helpers for subvolume name/id resolution
The functions will be used outside of export.c and super.c to allow
resolving subvolume name from a given id, eg. for subvolume deletion by
id ioctl.

Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ split from the next patch ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:42 +01:00
David Sterba
748449cdbe btrfs: use ioctl args support mask for device delete
When the device remove v2 ioctl was added, the full support mask was
added to sanity check the flags. However this would allow to let the
subvolume related flags to be accepted. This is not supposed to happen.

Use the correct support mask, which means that now any of
BTRFS_SUBVOL_CREATE_ASYNC, BTRFS_SUBVOL_RDONLY or
BTRFS_SUBVOL_QGROUP_INHERIT will be rejected as ENOTSUPP. Though this is
a user-visible change, specifying subvolume flags for device deletion
does not make sense and there are hopefully no applications doing that.

Reviewed-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:42 +01:00
David Sterba
673990dba3 btrfs: use ioctl args support mask for subvolume create/delete
Using the defined mask instead of flag enumeration in the ioctl handler
is preferred. No functional changes.

Reviewed-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:42 +01:00
David Sterba
eed0269053 btrfs: define support masks for ioctl volume args v2
The ioctl data for devices or subvolumes can be passed via
btrfs_ioctl_vol_args or btrfs_ioctl_vol_args_v2. The latter is more
versatile and needs some caution as some of the flags make sense only
for some ioctls.

As we're going to extend the flags, define support masks for each ioctl
class separately.

Reviewed-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:42 +01:00
Jules Irenge
5ce48d0f0e btrfs: Add missing lock annotation for release_extent_buffer()
Sparse reports a warning at release_extent_buffer()
warning: context imbalance in release_extent_buffer() - unexpected unlock

The root cause is the missing annotation at release_extent_buffer()
Add the missing __releases(&eb->refs_lock) annotation

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:42 +01:00
Josef Bacik
75ec1db871 btrfs: set update the uuid generation as soon as possible
In my EIO stress testing I noticed I was getting forced to rescan the
uuid tree pretty often, which was weird.  This is because my error
injection stuff would sometimes inject an error after log replay but
before we loaded the UUID tree.  If log replay committed the transaction
it wouldn't have updated the uuid tree generation, but the tree was
valid and didn't change, so there's no reason to not update the
generation here.

Fix this by setting the BTRFS_FS_UPDATE_UUID_TREE_GEN bit immediately
after reading all the fs roots if the uuid tree generation matches the
fs generation.  Then any transaction commits that happen during mount
won't screw up our uuid tree state, forcing us to do needless uuid
rescans.

Fixes: 70f8017547 ("Btrfs: check UUID tree during mount if required")
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:41 +01:00
Josef Bacik
c94bec2c61 btrfs: bail out of uuid tree scanning if we're closing
In doing my fsstress+EIO stress testing I started running into issues
where umount would get stuck forever because the uuid checker was
chewing through the thousands of subvolumes I had created.

We shouldn't block umount on this, simply bail if we're unmounting the
fs.  We need to make sure we don't mark the UUID tree as ok, so we only
set that bit if we made it through the whole rescan operation, but
otherwise this is completely safe.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:41 +01:00
Nikolay Borisov
97f4dd09da btrfs: make btrfs_check_uuid_tree private to disk-io.c
It's used only during filesystem mount as such it can be made private to
disk-io.c file. Also use the occasion to move btrfs_uuid_rescan_kthread
as btrfs_check_uuid_tree is its sole caller.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:41 +01:00
Nikolay Borisov
560b7a4aa2 btrfs: call btrfs_check_uuid_tree_entry directly in btrfs_uuid_tree_iterate
btrfs_uuid_tree_iterate is called from only once place and its 2nd
argument is always btrfs_check_uuid_tree_entry. Simplify
btrfs_uuid_tree_iterate's signature by removing its 2nd argument and
directly calling btrfs_check_uuid_tree_entry. Also move the latter into
uuid-tree.h. No functional changes.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:41 +01:00
David Sterba
c17af96554 btrfs: raid56: simplify tracking of Q stripe presence
There are temporary variables tracking the index of P and Q stripes, but
none of them is really used as such, merely for determining if the Q
stripe is present. This leads to compiler warnings with
-Wunused-but-set-variable and has been reported several times.

fs/btrfs/raid56.c: In function ‘finish_rmw’:
fs/btrfs/raid56.c:1199:6: warning: variable ‘p_stripe’ set but not used [-Wunused-but-set-variable]
 1199 |  int p_stripe = -1;
      |      ^~~~~~~~
fs/btrfs/raid56.c: In function ‘finish_parity_scrub’:
fs/btrfs/raid56.c:2356:6: warning: variable ‘p_stripe’ set but not used [-Wunused-but-set-variable]
 2356 |  int p_stripe = -1;
      |      ^~~~~~~~

Replace the two variables with one that has a clear meaning and also get
rid of the warnings. The logic that verifies that there are only 2
valid cases is unchanged.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:41 +01:00
ethanwu
b25b0b871f btrfs: backref, use correct count to resolve normal data refs
With the following patches:

- btrfs: backref, only collect file extent items matching backref offset
- btrfs: backref, not adding refs from shared block when resolving normal backref
- btrfs: backref, only search backref entries from leaves of the same root

we only collect the normal data refs we want, so the imprecise upper
bound total_refs of that EXTENT_ITEM could now be changed to the count
of the normal backref entry we want to search.

Background and how the patches fit together:

Btrfs has two types of data backref.
For BTRFS_EXTENT_DATA_REF_KEY type of backref, we don't have the
exact block number. Therefore, we need to call resolve_indirect_refs.
It uses btrfs_search_slot to locate the leaf block. Then
we need to walk through the leaves to search for the EXTENT_DATA items
that have disk bytenr matching the extent item (add_all_parents).

When resolving indirect refs, we could take entries that don't
belong to the backref entry we are searching for right now.
For that reason when searching backref entry, we always use total
refs of that EXTENT_ITEM rather than individual count.

For example:
item 11 key (40831553536 EXTENT_ITEM 4194304) itemoff 15460 itemsize
  extent refs 24 gen 7302 flags DATA
  shared data backref parent 394985472 count 10 #1
  extent data backref root 257 objectid 260 offset 1048576 count 3 #2
  extent data backref root 256 objectid 260 offset 65536 count 6 #3
  extent data backref root 257 objectid 260 offset 65536 count 5 #4

For example, when searching backref entry #4, we'll use total_refs
24, a very loose loop ending condition, instead of total_refs = 5.

But using total_refs = 24 is not accurate. Sometimes, we'll never find
all the refs from specific root.  As a result, the loop keeps on going
until we reach the end of that inode.

The first 3 patches, handle 3 different types refs we might encounter.
These refs do not belong to the normal backref we are searching, and
hence need to be skipped.

This patch changes the total_refs to correct number so that we could
end loop as soon as we find all the refs we want.

btrfs send uses backref to find possible clone sources, the following
is a simple test to compare the results with and without this patch:

 $ btrfs subvolume create /sub1
 $ for i in `seq 1 163840`; do
     dd if=/dev/zero of=/sub1/file bs=64K count=1 seek=$((i-1)) conv=notrunc oflag=direct
   done
 $ btrfs subvolume snapshot /sub1 /sub2
 $ for i in `seq 1 163840`; do
     dd if=/dev/zero of=/sub1/file bs=4K count=1 seek=$(((i-1)*16+10)) conv=notrunc oflag=direct
   done
 $ btrfs subvolume snapshot -r /sub1 /snap1
 $ time btrfs send /snap1 | btrfs receive /volume2

Without this patch:

real 69m48.124s
user 0m50.199s
sys  70m15.600s

With this patch:

real    1m59.683s
user    0m35.421s
sys     2m42.684s

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: ethanwu <ethanwu@synology.com>
[ add patchset cover letter with background and numbers ]
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:40 +01:00
ethanwu
cfc0eed0ec btrfs: backref, only search backref entries from leaves of the same root
We could have some nodes/leaves in subvolume whose owner are not the
that subvolume. In this way, when we resolve normal backrefs of that
subvolume, we should avoid collecting those references from these blocks.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: ethanwu <ethanwu@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:40 +01:00
ethanwu
ed58f2e66e btrfs: backref, don't add refs from shared block when resolving normal backref
All references from the block of SHARED_DATA_REF belong to that shared
block backref.

For example:

  item 11 key (40831553536 EXTENT_ITEM 4194304) itemoff 15460 itemsize 95
      extent refs 24 gen 7302 flags DATA
      extent data backref root 257 objectid 260 offset 65536 count 5
      extent data backref root 258 objectid 265 offset 0 count 9
      shared data backref parent 394985472 count 10

Block 394985472 might be leaf from root 257, and the item obejctid and
(file_pos - file_extent_item::offset) in that leaf just happens to be
260 and 65536 which is equal to the first extent data backref entry.

Before this patch, when we resolve backref:

  root 257 objectid 260 offset 65536

we will add those refs in block 394985472 and wrongly treat those as the
refs we want.

Fix this by checking if the leaf we are processing is shared data
backref, if so, just skip this leaf.

Shared data refs added into preftrees.direct have all entry value = 0
(root_id = 0, key = NULL, level = 0) except parent entry.

Other refs from indirect tree will have key value and root id != 0, and
these values won't be changed when their parent is resolved and added to
preftrees.direct. Therefore, we could reuse the preftrees.direct and
search ref with all values = 0 except parent is set to avoid getting
those resolved refs block.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: ethanwu <ethanwu@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:40 +01:00
ethanwu
7ac8b88ee6 btrfs: backref, only collect file extent items matching backref offset
When resolving one backref of type EXTENT_DATA_REF, we collect all
references that simply reference the EXTENT_ITEM even though their
(file_pos - file_extent_item::offset) are not the same as the
btrfs_extent_data_ref::offset we are searching for.

This patch adds additional check so that we only collect references whose
(file_pos - file_extent_item::offset) == btrfs_extent_data_ref::offset.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: ethanwu <ethanwu@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:40 +01:00
Johannes Thumshirn
9da2b242e2 btrfs: remove buffer_heads form super block mirror integrity checking
The integrity checking code for the super block mirrors is the last
remaining user of buffer_heads, change it to using plain bios as well.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:40 +01:00
Johannes Thumshirn
59aaad503f btrfs: remove buffer_heads from btrfsic_process_written_block()
Now that the last caller of btrfsic_process_written_block() with
buffer_heads is gone, remove the buffer_head processing path from it as
well.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:40 +01:00
Johannes Thumshirn
61ecc5fc18 btrfs: remove btrfsic_submit_bh()
Now that the last use of btrfsic_submit_bh() is gone as the super block
is now written using bios, remove the function as well.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:39 +01:00
Johannes Thumshirn
314b6dd0ee btrfs: use bios instead of buffer_heads from super block writeout
Similar to the superblock read path, change the write path to using bios
and pages instead of buffer_heads. This allows us to skip over the
buffer_head code, for writing the superblock to disk.

This is based on a patch originally authored by Nikolay Borisov.

Co-developed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:39 +01:00
Johannes Thumshirn
8f32380d3f btrfs: use the page cache for super block reading
Super-block reading in BTRFS is done using buffer_heads. Buffer_heads
have some drawbacks, like not being able to propagate errors from the
lower layers.

Directly use the page cache for reading the super blocks from disk or
invalidating an on-disk super block. We have to use the page cache so to
avoid races between mkfs and udev. See also 6f60cbd3ae ("btrfs: access
superblock via pagecache in scan_one_device").

This patch unwraps the buffer head API and does not change the way the
super block is actually read.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:39 +01:00
Johannes Thumshirn
6fbceb9fa4 btrfs: reduce scope of btrfs_scratch_superblocks()
btrfs_scratch_superblocks() isn't used anywhere outside volumes.c so
remove it from the header file and mark it as static.  Also move it
above it's callers so we don't need a forward declaration.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:39 +01:00
Johannes Thumshirn
c514c9b10b btrfs: don't kmap() pages from block devices
Block device mappings are never in highmem so kmap() / kunmap() calls for
pages from block devices are unneeded. Use page_address() instead of
kmap() to get to the virtual addreses.

While we're at it, read_cache_page_gfp() doesn't return NULL on error,
only an ERR_PTR, so use IS_ERR() to check for errors.

Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:39 +01:00
Nikolay Borisov
f6d9abbc1f btrfs: Export btrfs_release_disk_super
Preparatory patch for removal of buffer_head usage in btrfs.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:38 +01:00
Filipe Manana
55ffaabe23 Btrfs: avoid unnecessary splits when setting bits on an extent io tree
When attempting to set bits on a range of an exent io tree that already
has those bits set we can end up splitting an extent state record, use
the preallocated extent state record, insert it into the red black tree,
do another search on the red black tree, merge the preallocated extent
state record with the previous extent state record, remove that previous
record from the red black tree and then free it. This is all unnecessary
work that consumes time.

This happens specifically at the following case at __set_extent_bit():

  $ cat -n fs/btrfs/extent_io.c
   957  static int __must_check
   958  __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
  (...)
  1044          /*
  1045           *     | ---- desired range ---- |
  1046           * | state |
  1047           *   or
  1048           * | ------------- state -------------- |
  1049           *
  (...)
  1060          if (state->start < start) {
  1061                  if (state->state & exclusive_bits) {
  1062                          *failed_start = start;
  1063                          err = -EEXIST;
  1064                          goto out;
  1065                  }
  1066
  1067                  prealloc = alloc_extent_state_atomic(prealloc);
  1068                  BUG_ON(!prealloc);
  1069                  err = split_state(tree, state, prealloc, start);
  1070                  if (err)
  1071                          extent_io_tree_panic(tree, err);
  1072
  1073                  prealloc = NULL;

So if our extent state represents a range from 0 to 1MiB for example, and
we want to set bits in the range 128KiB to 256KiB for example, and that
extent state record already has all those bits set, we end up splitting
that record, so we end up with extent state records in the tree which
represent the ranges from 0 to 128KiB and from 128KiB to 1MiB. This is
temporary because a subsequent iteration in that function will end up
merging the records.

The splitting requires using the preallocated extent state record, so
a future iteration that needs to do another split will need to allocate
another extent state record in an atomic context, something not ideal
that we try to avoid as much as possible. The splitting also requires
an insertion in the red black tree, and a subsequent merge will require
a deletion from the red black tree and freeing an extent state record.

This change just skips the splitting of an extent state record when it
already has all the bits the we need to set.

Setting a bit that is already set for a range is very common in the
inode's 'file_extent_tree' extent io tree for example, where we keep
setting the EXTENT_DIRTY bit every time we replace an extent.

This change also fixes a bug that happens after the recent patchset from
Josef that avoids having implicit holes after a power failure when not
using the NO_HOLES feature, more specifically the patch with the subject:

  "btrfs: introduce the inode->file_extent_tree"

This patch introduced an extent io tree per inode to keep track of
completed ordered extents and figure out at any time what is the safe
value for the inode's disk_i_size. This assumes that for contiguous
ranges in a file we always end up with a single extent state record in
the io tree, but that is not the case, as there is a short time window
where we can have two extent state records representing contiguous
ranges. When this happens we end setting up an incorrect value for the
inode's disk_i_size, resulting in data loss after a clean unmount
of the filesystem. The following example explains how this can happen.

Suppose we have an inode with an i_size and a disk_i_size of 1MiB, so in
the inode's file_extent_tree we have a single extent state record that
represents the range [0, 1MiB) with the EXTENT_DIRTY bit set. Then the
following steps happen:

1) A buffered write against file range [512KiB, 768KiB) is made. At this
   point delalloc was not flushed yet;

2) Deduplication from some other inode into this inode's range
   [128KiB, 256KiB) is made. This causes btrfs_inode_set_file_extent_range()
   to be called, from btrfs_insert_clone_extent(), to mark the range
   [128KiB, 256KiB) with EXTENT_DIRTY in the inode's file_extent_tree;

3) When btrfs_inode_set_file_extent_range() calls set_extent_bits(), we
   end up at __set_extent_bit(). In the first iteration of that function's
   loop we end up in the following branch:

   $ cat -n fs/btrfs/extent_io.c
    957  static int __must_check
    958  __set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
   (...)
   1044          /*
   1045           *     | ---- desired range ---- |
   1046           * | state |
   1047           *   or
   1048           * | ------------- state -------------- |
   1049           *
   (...)
   1060          if (state->start < start) {
   1061                  if (state->state & exclusive_bits) {
   1062                          *failed_start = start;
   1063                          err = -EEXIST;
   1064                          goto out;
   1065                  }
   1066
   1067                  prealloc = alloc_extent_state_atomic(prealloc);
   1068                  BUG_ON(!prealloc);
   1069                  err = split_state(tree, state, prealloc, start);
   1070                  if (err)
   1071                          extent_io_tree_panic(tree, err);
   1072
   1073                  prealloc = NULL;
   (...)
   1089                  goto search_again;

   This splits the state record into two, one for range [0, 128KiB) and
   another for the range [128KiB, 1MiB). Both already have the EXTENT_DIRTY
   bit set. Then we jump to the 'search_again' label, where we unlock the
   the spinlock protecting the extent io tree before jumping to the
   'again' label to perform the next iteration;

4) In the meanwhile, delalloc is flushed, the ordered extent for the range
   [512KiB, 768KiB) is created and when it completes, at
   btrfs_finish_ordered_io(), it calls btrfs_inode_safe_disk_i_size_write()
   with a value of 0 for its 'new_size' argument;

5) Before the deduplication task currently at __set_extent_bit() moves to
   the next iteration, the task finishing the ordered extent calls
   find_first_extent_bit() through btrfs_inode_safe_disk_i_size_write()
   and gets 'start' set to 0 and 'end' set to 128KiB - because at this
   moment the io tree has two extent state records, one representing the
   range [0, 128KiB) and another representing the range [128KiB, 1MiB),
   both with EXTENT_DIRTY set. Then we set 'isize' to:

   isize = min(isize, end + 1)
         = min(1MiB, 128KiB - 1 + 1)
         = 128KiB

   Then we set the inode's disk_i_size to 128KiB (isize).

   After a clean unmount of the filesystem and mounting it again, we have
   the file with a size of 128KiB, and effectively lost all the data it
   had before in the range from 128KiB to 1MiB.

This change fixes that issue too, as we never end up splitting extent
state records when they already have all the bits we want set.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:38 +01:00
Josef Bacik
ab9b2c7b32 btrfs: handle logged extent failure properly
If we're allocating a logged extent we attempt to insert an extent
record for the file extent directly.  We increase
space_info->bytes_reserved, because the extent entry addition will call
btrfs_update_block_group(), which will convert the ->bytes_reserved to
->bytes_used.  However if we fail at any point while inserting the
extent entry we will bail and leave space on ->bytes_reserved, which
will trigger a WARN_ON() on umount.  Fix this by pinning the space if we
fail to insert, which is what happens in every other failure case that
involves adding the extent entry.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@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>
2020-03-23 17:01:38 +01:00
Qu Wenruo
e19221180d btrfs: relocation: Remove is_cowonly_root()
This function is only used in read_fs_root(), which is just a wrapper of
btrfs_get_fs_root().

For all the mentioned essential roots except log root tree,
btrfs_get_fs_root() has its own quick path to grab them from fs_info
directly, thus no need for key.offset modification.

For subvolume trees, btrfs_get_fs_root() with key.offset == -1 is
completely fine.

For log trees and log root tree, it's impossible to hit them, as for
relocation all backrefs are fetched from commit root, which never
records log tree blocks.

Log tree blocks either get freed in regular transaction commit, or
replayed at mount time. At runtime we should never hit an backref for
log tree in extent tree.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:38 +01:00
Nikolay Borisov
fe119a6eeb btrfs: switch to per-transaction pinned extents
This commit flips the switch to start tracking/processing pinned extents
on a per-transaction basis. It mostly replaces all references from
btrfs_fs_info::(pinned_extents|freed_extents[]) to
btrfs_transaction::pinned_extents.

Two notable modifications that warrant explicit mention are changing
clean_pinned_extents to get a reference to the previously running
transaction. The other one is removal of call to
btrfs_destroy_pinned_extent since transactions are going to be cleaned
in btrfs_cleanup_one_transaction.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:38 +01:00
Nikolay Borisov
45bb5d6ae9 btrfs: Factor out pinned extent clean up in btrfs_delete_unused_bgs
Next patch is going to refactor how pinned extents are tracked which
will necessitate changing this code. To ease that work and contain the
changes factor the code now in preparation, this will also help review.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:37 +01:00
Nikolay Borisov
f2fb72983b btrfs: Mark pinned log extents as excluded
In preparation to making pinned extents per-transaction ensure that log
such extents are always excluded from caching. To achieve this in
addition to marking them via btrfs_pin_extent_for_log_replay they also
need to be marked with btrfs_add_excluded_extent to prevent log tree
extent buffer being loaded by the free space caching thread. That's
required since log tree blocks are not recorded in the extent tree, hence
they always look free.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:37 +01:00
Nikolay Borisov
6b45f64172 btrfs: Pass transaction handle to write_pinned_extent_entries
Preparation for refactoring pinned extents tracking.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:37 +01:00
Nikolay Borisov
6690d07126 btrfs: Make pin_down_extent take transaction handle
All callers have a reference to a transaction handle so pass it to
pin_down_extent. This is the final step before switching pinned extent
tracking to a per-transaction basis.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:37 +01:00
Nikolay Borisov
9fce570454 btrfs: Make btrfs_pin_extent_for_log_replay take transaction handle
Preparation for refactoring pinned extents tracking.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:37 +01:00
Nikolay Borisov
7bfc100705 btrfs: Make btrfs_pin_reserved_extent take transaction handle
btrfs_pin_reserved_extent is now only called with a valid transaction so
exploit the fact to take a transaction. This is preparation for tracking
pinned extents on a per-transaction basis.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:37 +01:00
Nikolay Borisov
10e958d523 btrfs: Call btrfs_pin_reserved_extent only during active transaction
Calling btrfs_pin_reserved_extent makes sense only with a valid
transaction since pinned extents are processed from transaction commit
in btrfs_finish_extent_commit. In case of error it's sufficient to
adjust the reserved counter to account for log tree extents allocated in
the last transaction.

This commit moves btrfs_pin_reserved_extent to be called only with valid
transaction handle and otherwise uses the newly introduced
unaccount_log_buffer to adjust "reserved". If this is not done if a
failure occurs before transaction is committed WARN_ON are going to be
triggered on unmount. This was especially pronounced with generic/475
test.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:36 +01:00
Nikolay Borisov
6787bb9f35 btrfs: Introduce unaccount_log_buffer
This function correctly adjusts the reserved bytes occupied by a log
tree extent buffer. It will be used instead of calling
btrfs_pin_reserved_extent.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:36 +01:00
Nikolay Borisov
b25c36f84b btrfs: Make btrfs_pin_extent take trans handle
Preparation for switching pinned extent tracking to a per-transaction
basis.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:36 +01:00
Nikolay Borisov
f603bb94ab btrfs: Perform pinned cleanup directly in btrfs_destroy_delayed_refs
Having btrfs_destroy_delayed_refs call btrfs_pin_extent is problematic
for making pinned extents tracking per-transaction since
btrfs_trans_handle cannot be passed to btrfs_pin_extent in this context.
Additionally delayed refs heads pinned in btrfs_destroy_delayed_refs
are going to be handled very closely, in btrfs_destroy_pinned_extent.

To enable btrfs_pin_extent to take btrfs_trans_handle simply open code
it in btrfs_destroy_delayed_refs and call btrfs_error_unpin_extent_range
on the range. This enables us to do less work in
btrfs_destroy_pinned_extent and leaves btrfs_pin_extent being called in
contexts which have a valid btrfs_trans_handle.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:36 +01:00
Anand Jain
25864778bc btrfs: sysfs, unify handler name of devinfo/missing
The devinfo attribute handlers were added in 668e48af7a ("btrfs:
sysfs, add devid/dev_state kobject and device attributes") and the name
should contain _devinfo_, there's one that does not conform, so unify it
with the rest.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:36 +01:00
Anand Jain
f3cd2c5811 btrfs: sysfs, rename device_link add/remove functions
Since commit 668e48af7a ("btrfs: sysfs, add devid/dev_state kobject and
device attributes"), the functions btrfs_sysfs_add_device_link() and
btrfs_sysfs_rm_device_link() do more than just adding and removing the
device link as its name indicated. Rename them to be more specific
that's about the directory with the attirbutes

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:35 +01:00
Anand Jain
1f6087e69c btrfs: sysfs, use btrfs_sysfs_remove_fsid to celanup errors in add_fsid
We have one simple function btrfs_sysfs_remove_fsid() to undo
btrfs_sysfs_add_fsid(), which also does proper checks before releasing
objects.

One difference, if btrfs_sysfs_remove_fsid is used that now we also call
kobject_del() which was missing before. This was tested (with kobject
debug turned on) and no change in behaviour was found.

This is a cleanup patch.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:35 +01:00
David Sterba
f657a31c86 btrfs: sink argument tree to __do_readpage
The tree pointer can be safely read from the inode, use it and drop the
redundant argument.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:35 +01:00
David Sterba
b6660e80f1 btrfs: sink arugment tree to contiguous_readpages
The tree pointer can be safely read from the inode, use it and drop the
redundant argument.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:35 +01:00
David Sterba
0d44fea77e btrfs: sink argument tree to __extent_read_full_page
The tree pointer can be safely read from the inode, use it and drop the
redundant argument.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:35 +01:00
David Sterba
71ad38b44e btrfs: sink argument tree to extent_read_full_page
The tree pointer can be safely read from the page's inode, use it and
drop the redundant argument.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:35 +01:00
David Sterba
b272ae22ac btrfs: drop argument tree from btrfs_lock_and_flush_ordered_range
The tree pointer can be safely read from the inode so we can drop the
redundant argument from btrfs_lock_and_flush_ordered_range.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:34 +01:00
David Sterba
ae6957ebbf btrfs: add assertions for tree == inode->io_tree to extent IO helpers
Add assertions to all helpers that get tree as argument and verify that
it's the same that can be obtained from the inode or from its pages. In
followup patches the redundant arguments and assertions will be removed
one by one.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-03-23 17:01:34 +01:00