linux-stable.git/fs/btrfs/compression.c, branch linux-6.3.y

btrfs: split zone append bios in btrfs_submit_bio

2023-02-15T18:38:53+00:00

The current btrfs zoned device support is a little cumbersome in the data
I/O path as it requires the callers to not issue I/O larger than the
supported ZONE_APPEND size of the underlying device.  This leads to a lot
of extra accounting.  Instead change btrfs_submit_bio so that it can take
write bios of arbitrary size and form from the upper layers, and just
split them internally to the ZONE_APPEND queue limits.  Then remove all
the upper layer warts catering to limited write sized on zoned devices,
including the extra refcount in the compressed_bio.

Reviewed-by: Josef Bacik 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Christoph Hellwig 
Signed-off-by: David Sterba

btrfs: remove the fs_info argument to btrfs_submit_bio

2023-02-15T18:38:53+00:00

btrfs_submit_bio can derive it trivially from bbio->inode, so stop
bothering in the callers.

Reviewed-by: Josef Bacik 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Christoph Hellwig 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: remove stripe boundary calculation for compressed I/O

2023-02-15T18:38:52+00:00

Stop looking at the stripe boundary in alloc_compressed_bio() now that
that btrfs_submit_bio can split bios, open code the now trivial code
from alloc_compressed_bio() in btrfs_submit_compressed_read and stop
maintaining the pending_ios count for reads as there is always just
a single bio now.

Reviewed-by: Josef Bacik 
Signed-off-by: Qu Wenruo 
[hch: remove more cruft in btrfs_submit_compressed_read,
      use btrfs_zoned_get_device in alloc_compressed_bio]
Signed-off-by: Christoph Hellwig 
Signed-off-by: David Sterba

btrfs: handle recording of zoned writes in the storage layer

2023-02-15T18:38:52+00:00

Move the code that splits the ordered extents and records the physical
location for them to the storage layer so that the higher level consumers
don't have to care about physical block numbers at all.  This will also
allow to eventually remove accounting for the zone append write sizes in
the upper layer with a little bit more block layer work.

Reviewed-by: Naohiro Aota 
Reviewed-by: Josef Bacik 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Christoph Hellwig 
Signed-off-by: David Sterba

btrfs: handle checksum generation in the storage layer

2023-02-15T18:38:52+00:00

Instead of letting the callers of btrfs_submit_bio deal with checksumming
the (meta)data in the bio and making decisions on when to offload the
checksumming to the bio, leave that to btrfs_submit_bio.  Do do so the
existing btrfs_submit_bio function is split into an upper and a lower
half, so that the lower half can be offloaded to a workqueue.

Note that this changes the behavior for direct writes to raid56 volumes so
that async checksum offloading is not skipped when more I/O is expected.
This runs counter to the argument explaining why it was done, although I
can't measure any affects of the change.  Commits later in this series
will make sure the entire direct writes is offloaded to the workqueue
at once and thus make sure it is sent to the raid56 code from a single
thread.

Reviewed-by: Josef Bacik 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Christoph Hellwig 
Signed-off-by: David Sterba

btrfs: simplify the btrfs_csum_one_bio calling convention

2023-02-15T18:38:52+00:00

To prepare for further bio submission changes btrfs_csum_one_bio
should be able to take all it's arguments from the btrfs_bio structure.
It can always use the bbio->inode already, and once the compression code
is updated to set ->file_offset that one can be used unconditionally
as well instead of looking at the page mapping now that btrfs doesn't
allow ordered extents to span discontiguous data ranges.

The only slightly tricky bit is the one_ordered flag set by the
compressed writes.  Replace that one with the driver private bio
flag, which gets cleared before the bio is handed off to the block layer
so that we don't get in the way of driver use.

Note: this leaves an argument and a flag to btrfs_wq_submit_bio unused.
But that whole mechanism will be removed in its current form in the
next patch.

Reviewed-by: Josef Bacik 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Christoph Hellwig 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: handle checksum validation and repair at the storage layer

2023-02-15T18:38:51+00:00

Currently btrfs handles checksum validation and repair in the end I/O
handler for the btrfs_bio.  This leads to a lot of duplicate code
plus issues with varying semantics or bugs, e.g.

- the until recently broken repair for compressed extents
- the fact that encoded reads validate the checksums but do not kick
  of read repair
- the inconsistent checking of the BTRFS_FS_STATE_NO_CSUMS flag

This commit revamps the checksum validation and repair code to instead
work below the btrfs_submit_bio interfaces.

In case of a checksum failure (or a plain old I/O error), the repair
is now kicked off before the upper level ->end_io handler is invoked.

Progress of an in-progress repair is tracked by a small structure
that is allocated using a mempool for each original bio with failed
sectors, which holds a reference to the original bio.   This new
structure is allocated using a mempool to guarantee forward progress
even under memory pressure.  The mempool will be replenished when
the repair completes, just as the mempools backing the bios.

There is one significant behavior change here:  If repair fails or
is impossible to start with, the whole bio will be failed to the
upper layer.  This is the behavior that all I/O submitters except
for buffered I/O already emulated in their end_io handler.  For
buffered I/O this now means that a large readahead request can
fail due to a single bad sector, but as readahead errors are ignored
the following readpage if the sector is actually accessed will
still be able to read.  This also matches the I/O failure handling
in other file systems.

Reviewed-by: Josef Bacik 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Christoph Hellwig 
Signed-off-by: David Sterba

btrfs: pre-load data checksum for reads in btrfs_submit_bio

2023-02-15T18:38:51+00:00

Instead of calling btrfs_lookup_bio_sums in every caller of
btrfs_submit_bio that reads data, do the call once in btrfs_submit_bio.

Reviewed-by: Johannes Thumshirn 
Signed-off-by: Christoph Hellwig 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: save the bio iter for checksum validation in common code

2023-02-15T18:38:51+00:00

All callers of btrfs_submit_bio that want to validate checksums
currently have to store a copy of the iter in the btrfs_bio.  Move
the assignment into common code.

Reviewed-by: Johannes Thumshirn 
Signed-off-by: Christoph Hellwig 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: simplify parameters of btrfs_lookup_bio_sums

2023-02-15T18:38:50+00:00

The csums argument is always NULL now, so remove it and always allocate
the csums array in the btrfs_bio.  Also pass the btrfs_bio instead of
inode + bio to document that this function requires a btrfs_bio and
not just any bio.

Reviewed-by: Johannes Thumshirn 
Reviewed-by: Anand Jain 
Signed-off-by: Christoph Hellwig 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba