btrfs: do not subtract delalloc from avail bytes

commit d89c285d28491d8f10534c262ac9e6bdcbe1b4d2 upstream.

The block group's avail bytes printed when dumping a space info subtract
the delalloc_byte

btrfs: do not subtract delalloc from avail bytes

commit d89c285d28491d8f10534c262ac9e6bdcbe1b4d2 upstream.

The block group's avail bytes printed when dumping a space info subtract
the delalloc_bytes. However, as shown in btrfs_add_reserved_bytes() and
btrfs_free_reserved_bytes(), it is added or subtracted along with
"reserved" for the delalloc case, which means the "delalloc_bytes" is a
part of the "reserved" bytes. So, excluding it to calculate the avail space
counts delalloc_bytes twice, which can lead to an invalid result.

Fixes: e50b122b832b ("btrfs: print available space for a block group when dumping a space info")
CC: stable@vger.kernel.org # 6.6+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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btrfs: zoned: fix zone_unusable accounting on making block group read-write again

commit 8cd44dd1d17a23d5cc8c443c659ca57aa76e2fa5 upstream.

When btrfs makes a block group read-only, it adds all fre

btrfs: zoned: fix zone_unusable accounting on making block group read-write again

commit 8cd44dd1d17a23d5cc8c443c659ca57aa76e2fa5 upstream.

When btrfs makes a block group read-only, it adds all free regions in the
block group to space_info->bytes_readonly. That free space excludes
reserved and pinned regions. OTOH, when btrfs makes the block group
read-write again, it moves all the unused regions into the block group's
zone_unusable. That unused region includes reserved and pinned regions.
As a result, it counts too much zone_unusable bytes.

Fortunately (or unfortunately), having erroneous zone_unusable does not
affect the calculation of space_info->bytes_readonly, because free
space (num_bytes in btrfs_dec_block_group_ro) calculation is done based on
the erroneous zone_unusable and it reduces the num_bytes just to cancel the
error.

This behavior can be easily discovered by adding a WARN_ON to check e.g,
"bg->pinned > 0" in btrfs_dec_block_group_ro(), and running fstests test
case like btrfs/282.

Fix it by properly considering pinned and reserved in
btrfs_dec_block_group_ro(). Also, add a WARN_ON and introduce
btrfs_space_info_update_bytes_zone_unusable() to catch a similar mistake.

Fixes: 169e0da91a21 ("btrfs: zoned: track unusable bytes for zones")
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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btrfs: fix data races when accessing the reserved amount of block reserves

[ Upstream commit e06cc89475eddc1f3a7a4d471524256152c68166 ]

At space_info.c we have several places where we access the ->

btrfs: fix data races when accessing the reserved amount of block reserves

[ Upstream commit e06cc89475eddc1f3a7a4d471524256152c68166 ]

At space_info.c we have several places where we access the ->reserved
field of a block reserve without taking the block reserve's spinlock
first, which makes KCSAN warn about a data race since that field is
always updated while holding the spinlock.

The reports from KCSAN are like the following:

[117.193526] BUG: KCSAN: data-race in btrfs_block_rsv_release [btrfs] / need_preemptive_reclaim [btrfs]

[117.195148] read to 0x000000017f587190 of 8 bytes by task 6303 on cpu 3:
[117.195172] need_preemptive_reclaim+0x222/0x2f0 [btrfs]
[117.195992] __reserve_bytes+0xbb0/0xdc8 [btrfs]
[117.196807] btrfs_reserve_metadata_bytes+0x4c/0x120 [btrfs]
[117.197620] btrfs_block_rsv_add+0x78/0xa8 [btrfs]
[117.198434] btrfs_delayed_update_inode+0x154/0x368 [btrfs]
[117.199300] btrfs_update_inode+0x108/0x1c8 [btrfs]
[117.200122] btrfs_dirty_inode+0xb4/0x140 [btrfs]
[117.200937] btrfs_update_time+0x8c/0xb0 [btrfs]
[117.201754] touch_atime+0x16c/0x1e0
[117.201789] filemap_read+0x674/0x728
[117.201823] btrfs_file_read_iter+0xf8/0x410 [btrfs]
[117.202653] vfs_read+0x2b6/0x498
[117.203454] ksys_read+0xa2/0x150
[117.203473] __s390x_sys_read+0x68/0x88
[117.203495] do_syscall+0x1c6/0x210
[117.203517] __do_syscall+0xc8/0xf0
[117.203539] system_call+0x70/0x98

[117.203579] write to 0x000000017f587190 of 8 bytes by task 11 on cpu 0:
[117.203604] btrfs_block_rsv_release+0x2e8/0x578 [btrfs]
[117.204432] btrfs_delayed_inode_release_metadata+0x7c/0x1d0 [btrfs]
[117.205259] __btrfs_update_delayed_inode+0x37c/0x5e0 [btrfs]
[117.206093] btrfs_async_run_delayed_root+0x356/0x498 [btrfs]
[117.206917] btrfs_work_helper+0x160/0x7a0 [btrfs]
[117.207738] process_one_work+0x3b6/0x838
[117.207768] worker_thread+0x75e/0xb10
[117.207797] kthread+0x21a/0x230
[117.207830] __ret_from_fork+0x6c/0xb8
[117.207861] ret_from_fork+0xa/0x30

So add a helper to get the reserved amount of a block reserve while
holding the lock. The value may be not be up to date anymore when used by
need_preemptive_reclaim() and btrfs_preempt_reclaim_metadata_space(), but
that's ok since the worst it can do is cause more reclaim work do be done
sooner rather than later. Reading the field while holding the lock instead
of using the data_race() annotation is used in order to prevent load
tearing.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

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btrfs: zoned: re-enable metadata over-commit for zoned mode

Now that, we can re-enable metadata over-commit. As we moved the activation
from the reservation time to the write time, we no longer need

btrfs: zoned: re-enable metadata over-commit for zoned mode

Now that, we can re-enable metadata over-commit. As we moved the activation
from the reservation time to the write time, we no longer need to ensure
all the reserved bytes is properly activated.

Without the metadata over-commit, it suffers from lower performance because
it needs to flush the delalloc items more often and allocate more block
groups. Re-enabling metadata over-commit will solve the issue.

Fixes: 79417d040f4f ("btrfs: zoned: disable metadata overcommit for zoned")
CC: stable@vger.kernel.org # 6.1+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: zoned: don't activate non-DATA BG on allocation

Now that a non-DATA block group is activated at write time, don't
activate it on allocation time.

Reviewed-by: Johannes Thumshirn <johannes.th

btrfs: zoned: don't activate non-DATA BG on allocation

Now that a non-DATA block group is activated at write time, don't
activate it on allocation time.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: avoid starting and committing empty transaction when flushing space

When flushing space and we are in the COMMIT_TRANS state, we join a
transaction with btrfs_join_transaction() and then comm

btrfs: avoid starting and committing empty transaction when flushing space

When flushing space and we are in the COMMIT_TRANS state, we join a
transaction with btrfs_join_transaction() and then commit the returned
transaction. However btrfs_join_transaction() starts a new transaction if
there is none currently open, which is pointless since comitting a new,
empty transaction, doesn't achieve anything, it only wastes time, IO and
creates an unnecessary rotation of the backup roots.

So use btrfs_attach_transaction_barrier() to avoid starting a new
transaction. This also waits for any ongoing transaction that is
committing (state >= TRANS_STATE_COMMIT_DOING) to fully complete, and
therefore wait for all the extents that were pinned during the
transaction's lifetime to be unpinned.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: avoid starting new transaction when flushing delayed items and refs

When flushing space we join a transaction to flush delayed items and
delayed references, in order to try to release space.

btrfs: avoid starting new transaction when flushing delayed items and refs

When flushing space we join a transaction to flush delayed items and
delayed references, in order to try to release space. However using
btrfs_join_transaction() not only joins an existing transaction as well
as it starts a new transaction if there is none open. If there is no
transaction open, we don't have neither delayed items nor delayed
references, so creating a new transaction is a waste of time, IO and
creates an unnecessary rotation of the backup roots without gaining any
benefits (including releasing space).

So use btrfs_join_transaction_nostart() when attempting to flush delayed
items and references.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: fail priority metadata ticket with real fs error

At priority_reclaim_metadata_space(), if we were not able to satisfy the
the ticket after going through the various flushing states and we not

btrfs: fail priority metadata ticket with real fs error

At priority_reclaim_metadata_space(), if we were not able to satisfy the
the ticket after going through the various flushing states and we notice
the fs went into an error state, likely due to a transaction abort during
the flushing, set the ticket's error to the error that caused the
transaction abort instead of an unconditional -EROFS.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: don't steal space from global rsv after a transaction abort

When doing a priority metadata space reclaim, while we are going through
the flush states and running their respective operations,

btrfs: don't steal space from global rsv after a transaction abort

When doing a priority metadata space reclaim, while we are going through
the flush states and running their respective operations, it's possible
that a transaction abort happened, for example when running delayed refs
we hit -ENOSPC or in the critical section of transaction commit we failed
with -ENOSPC or some other error. In these cases a transaction was aborted
and the fs turned into error state. If that happened, then it makes no
sense to steal from the global block reserve and return success to the
caller if the stealing was successful - the caller will later get an
error when attempting to modify the fs. Instead make the ticket fail if
we have the fs in error state and don't attempt to steal from the global
rsv, as it's not only it's pointless, it also simplifies debugging some
-ENOSPC problems.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: print available space across all block groups when dumping space info

When dumping a space info also sum the available space for all block
groups and then print it. This often useful for debu

btrfs: print available space across all block groups when dumping space info

When dumping a space info also sum the available space for all block
groups and then print it. This often useful for debugging -ENOSPC
related problems.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: print available space for a block group when dumping a space info

When dumping a space info, we iterate over all its block groups and then
print their size and the amounts of bytes used, rese

btrfs: print available space for a block group when dumping a space info

When dumping a space info, we iterate over all its block groups and then
print their size and the amounts of bytes used, reserved, pinned, etc.
When debugging -ENOSPC problems it's also useful to know how much space
is available (free), so calculate that and print it as well.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: print block group super and delalloc bytes when dumping space info

When dumping a space info's block groups, also print the number of bytes
used for super blocks and delalloc. This is often u

btrfs: print block group super and delalloc bytes when dumping space info

When dumping a space info's block groups, also print the number of bytes
used for super blocks and delalloc. This is often useful for debugging
-ENOSPC problems.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: add helper to calculate space for delayed references

Instead of duplicating the logic for calculating how much space is
required for a given number of delayed references, add an inline helper

btrfs: add helper to calculate space for delayed references

Instead of duplicating the logic for calculating how much space is
required for a given number of delayed references, add an inline helper
to encapsulate that logic and use it everywhere we are calculating the
space required.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: constify fs_info argument for the reclaim items calculation helpers

Now that btrfs_calc_insert_metadata_size() can take a const fs_info
argument, make the fs_info argument of calc_reclaim_ite

btrfs: constify fs_info argument for the reclaim items calculation helpers

Now that btrfs_calc_insert_metadata_size() can take a const fs_info
argument, make the fs_info argument of calc_reclaim_items_nr() and of
calc_delayed_refs_nr() const as well.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: accurately calculate number of delayed refs when flushing

When flushing a limited number of delayed references (FLUSH_DELAYED_REFS_NR
state), we are assuming each delayed reference is holding

btrfs: accurately calculate number of delayed refs when flushing

When flushing a limited number of delayed references (FLUSH_DELAYED_REFS_NR
state), we are assuming each delayed reference is holding a number of bytes
matching the needed space for inserting for a single metadata item (the
result of btrfs_calc_insert_metadata_size()). That is not correct when
using the free space tree, as in that case we have to multiply that value
by 2 since we need to touch the free space tree as well. This is the same
computation as we do at btrfs_update_delayed_refs_rsv() and at
btrfs_delayed_refs_rsv_release().

So correct the computation for the amount of delayed references we need to
flush in case we have the free space tree. This does not fix a functional
issue, instead it makes the flush code flush less delayed references, only
the minimum necessary to satisfy a ticket.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: initialize ret to -ENOSPC at __reserve_bytes()

At space-info.c:__reserve_bytes(), instead of initializing 'ret' to 0 when
it's declared and then shortly after set it to -ENOSPC under the spac

btrfs: initialize ret to -ENOSPC at __reserve_bytes()

At space-info.c:__reserve_bytes(), instead of initializing 'ret' to 0 when
it's declared and then shortly after set it to -ENOSPC under the space
info's spinlock, initialize it to -ENOSPC when declaring it.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: update flush method assertion when reserving space

When reserving space, at space-info.c:__reserve_bytes(), we assert that
either the current task is not holding a transacion handle, or, if i

btrfs: update flush method assertion when reserving space

When reserving space, at space-info.c:__reserve_bytes(), we assert that
either the current task is not holding a transacion handle, or, if it is,
that the flush method is not BTRFS_RESERVE_FLUSH_ALL. This is because that
flush method can trigger transaction commits, and therefore could lead to
a deadlock.

However there are other 2 flush methods that can trigger transaction
commits:

1) BTRFS_RESERVE_FLUSH_ALL_STEAL
2) BTRFS_RESERVE_FLUSH_EVICT

So update the assertion to check the flush method is also not one those
two methods if the current task is holding a transaction handle.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: zoned: drop space_info->active_total_bytes

The space_info->active_total_bytes is no longer necessary as we now
count the region of newly allocated block group as zone_unusable. Drop
its usage

btrfs: zoned: drop space_info->active_total_bytes

The space_info->active_total_bytes is no longer necessary as we now
count the region of newly allocated block group as zone_unusable. Drop
its usage.

Fixes: 6a921de58992 ("btrfs: zoned: introduce space_info->active_total_bytes")
CC: stable@vger.kernel.org # 6.1+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: rename BTRFS_FS_NO_OVERCOMMIT to BTRFS_FS_ACTIVE_ZONE_TRACKING

This flag only gets set when we're doing active zone tracking, and we're
going to need to use this flag for things related to th

btrfs: rename BTRFS_FS_NO_OVERCOMMIT to BTRFS_FS_ACTIVE_ZONE_TRACKING

This flag only gets set when we're doing active zone tracking, and we're
going to need to use this flag for things related to this behavior.
Rename the flag to represent what it actually means for the file system
so it can be used in other ways and still make sense.

Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: zoned: enable metadata over-commit for non-ZNS setup

The commit 79417d040f4f ("btrfs: zoned: disable metadata overcommit for
zoned") disabled the metadata over-commit to track active zones pr

btrfs: zoned: enable metadata over-commit for non-ZNS setup

The commit 79417d040f4f ("btrfs: zoned: disable metadata overcommit for
zoned") disabled the metadata over-commit to track active zones properly.

However, it also introduced a heavy overhead by allocating new metadata
block groups and/or flushing dirty buffers to release the space
reservations. Specifically, a workload (write only without any sync
operations) worsen its performance from 343.77 MB/sec (v5.19) to 182.89
MB/sec (v6.0).

The performance is still bad on current misc-next which is 187.95 MB/sec.
And, with this patch applied, it improves back to 326.70 MB/sec (+73.82%).

This patch introduces a new fs_info->flag BTRFS_FS_NO_OVERCOMMIT to
indicate it needs to disable the metadata over-commit. The flag is enabled
when a device with max active zones limit is loaded into a file-system.

Fixes: 79417d040f4f ("btrfs: zoned: disable metadata overcommit for zoned")
CC: stable@vger.kernel.org # 6.0+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: simplify percent calculation helpers, rename div_factor

The div_factor* helpers calculate fraction or percentage fraction. The
name is a bit confusing, we use it only for percentage calculati

btrfs: simplify percent calculation helpers, rename div_factor

The div_factor* helpers calculate fraction or percentage fraction. The
name is a bit confusing, we use it only for percentage calculations and
there are two helpers.

There's a helper mult_frac that's for general fractions, that tries to
be accurate but we multiply and divide by small numbers so we can use
the div_u64 helper.

Rename the div_factor* helpers and use 1..100 percentage range, also drop
the case checking for percentage == 100, it's never hit.

The conversions:

* div_factor calculates tenths and the numbers need to be adjusted
* div_factor_fine is direct replacement

Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: update function comments

Update, reformat or reword function comments. This also removes the kdoc
marker so we don't get reports when the function name is missing.

Changes made:

- remove kd

btrfs: update function comments

Update, reformat or reword function comments. This also removes the kdoc
marker so we don't get reports when the function name is missing.

Changes made:

- remove kdoc markers
- reformat the brief description to be a proper sentence
- reword to imperative voice
- align parameter list
- fix typos

Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: move extent-tree helpers into their own header file

Move all the extent tree related prototypes to extent-tree.h out of
ctree.h, and then go include it everywhere needed so everything
compile

btrfs: move extent-tree helpers into their own header file

Move all the extent tree related prototypes to extent-tree.h out of
ctree.h, and then go include it everywhere needed so everything
compiles.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: move btrfs_account_ro_block_groups_free_space into space-info.c

This was prototyped in ctree.h and the code existed in extent-tree.c,
but it's space-info related so move it into space-info.c.

btrfs: move btrfs_account_ro_block_groups_free_space into space-info.c

This was prototyped in ctree.h and the code existed in extent-tree.c,
but it's space-info related so move it into space-info.c.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

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btrfs: move accessor helpers into accessors.h

This is a large patch, but because they're all macros it's impossible to
split up. Simply copy all of the item accessors in ctree.h and paste
them in a

btrfs: move accessor helpers into accessors.h

This is a large patch, but because they're all macros it's impossible to
split up. Simply copy all of the item accessors in ctree.h and paste
them in accessors.h, and then update any files to include the header so
everything compiles.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ reformat comments, style fixups ]
Signed-off-by: David Sterba <dsterba@suse.com>

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