linux.git/fs/btrfs/relocation.c, branch v6.14

btrfs: open code set_page_extent_mapped()

2025-01-13T13:53:22+00:00

The function set_page_extent_mapped() is now a simple wrapper so use the
folio helper.

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

btrfs: relocation: remove unnecessary calls to btrfs_mark_buffer_dirty()

2025-01-13T13:53:20+00:00

We have several places explicitly calling btrfs_mark_buffer_dirty() but
that is not necessarily since the target leaf came from a path that was
obtained for a btree search function that modifies the btree, something
like btrfs_insert_empty_item() or anything else that ends up calling
btrfs_search_slot() with a value of 1 for its 'cow' argument.

These just make the code more verbose, confusing and add a little extra
overhead and well as increase the module's text size, so remove them.

Reviewed-by: Johannes Thumshirn 
Signed-off-by: Filipe Manana 
Signed-off-by: David Sterba

btrfs: remove detached list from struct btrfs_backref_cache

2025-01-13T13:53:15+00:00

We don't ever look at this list, remove it.

Reviewed-by: Boris Burkov 
Signed-off-by: Josef Bacik 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: remove the ->lowest and ->leaves members from struct btrfs_backref_node

2025-01-13T13:53:15+00:00

Before we were keeping all of our nodes on various lists in order to
make sure everything got cleaned up correctly.  We used node->lowest to
indicate that node->lower was linked into the cache->leaves list.  Now
that we do cleanup based on the rb-tree both the list and the flag are
useless, so delete them both.

Reviewed-by: Boris Burkov 
Signed-off-by: Josef Bacik 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: do not handle non-shareable roots in backref cache

2025-01-13T13:53:15+00:00

Now that we handle relocation for non-shareable roots without using the
backref cache, remove the ->cowonly field from the backref nodes and
update the handling to throw an error.

Reviewed-by: Boris Burkov 
Signed-off-by: Josef Bacik 
Signed-off-by: David Sterba

btrfs: don't build backref tree for COW-only blocks

2025-01-13T13:53:15+00:00

We already determine the owner for any blocks we find when we're
relocating, and for COW-only blocks (and the data reloc tree) we COW
down to the block and call it good enough.  However we still build a
whole backref tree for them, even though we're not going to use it, and
then just don't put these blocks in the cache.

Rework the code to check if the block belongs to a COW-only root or the
data reloc root, and then just cow down to the block, skipping the
backref cache generation.

Reviewed-by: Boris Burkov 
Signed-off-by: Josef Bacik 
Signed-off-by: David Sterba

btrfs: remove clone_backref_node() from relocation

2025-01-13T13:53:15+00:00

Since we no longer maintain backref cache across transactions, and this
is only called when we're creating the reloc root for a newly created
snapshot in the transaction critical section, we will end up doing a
bunch of work that will just get thrown away when we start the
transaction in the relocation loop.  Delete this code as it no longer
does anything for us.

Reviewed-by: Boris Burkov 
Signed-off-by: Josef Bacik 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: simplify loop in select_reloc_root()

2025-01-13T13:53:15+00:00

We have this setup as a loop, but in reality we will never walk back up
the backref tree, if we do then it's a bug.  Get rid of the loop and
handle the case where we have node->new_bytenr set at all.  Previous
check was only if node->new_bytenr != root->node->start, but if it did
then we would hit the WARN_ON() and walk back up the tree.

Instead we want to just return error if ->new_bytenr is set, and then do
the normal updating of the node for the reloc root and carry on.

Reviewed-by: Boris Burkov 
Signed-off-by: Josef Bacik 
Signed-off-by: David Sterba

btrfs: remove the changed list for backref cache

2025-01-13T13:53:14+00:00

Now that we're not updating the backref cache when we switch transids we
can remove the changed list.

We're going to keep the new_bytenr field because it serves as a good
sanity check for the backref cache and relocation, and can prevent us
from making extent tree corruption worse.

Reviewed-by: Boris Burkov 
Signed-off-by: Josef Bacik 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

btrfs: convert BUG_ON in btrfs_reloc_cow_block() to proper error handling

2025-01-13T13:53:14+00:00

This BUG_ON is meant to catch backref cache problems, but these can
arise from either bugs in the backref cache or corruption in the extent
tree.  Fix it to be a proper error.

Reviewed-by: Boris Burkov 
Signed-off-by: Josef Bacik 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba