[PATCH 5.15 08/20] btrfs: zoned: use regular writes for relocation

Greg Kroah-Hartman
2021-11-19T17:40:22Z

From: Johannes Thumshirn <johannes.thumshirn@wdc.com>

commit e6d261e3b1f777b499ce8f535ed44dd1b69278b7 upstream

Now that we have a dedicated block group for relocation, we can use
REQ_OP_WRITE instead of REQ_OP_ZONE_APPEND for writing out the data on
relocation.

Reviewed-by: Naohiro Aota <naohiro.aota@wdc.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>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/btrfs/zoned.c | 11 +++++++++++
1 file changed, 11 insertions(+)

--- a/fs/btrfs/zoned.c
+++ b/fs/btrfs/zoned.c
@@ -1304,6 +1304,17 @@ bool btrfs_use_zone_append(struct btrfs_
if (!is_data_inode(&inode->vfs_inode))
return false;

+ /*
+ * Using REQ_OP_ZONE_APPNED for relocation can break assumptions on the
+ * extent layout the relocation code has.
+ * Furthermore we have set aside own block-group from which only the
+ * relocation "process" can allocate and make sure only one process at a
+ * time can add pages to an extent that gets relocated, so it's safe to
+ * use regular REQ_OP_WRITE for this special case.
+ */
+ if (btrfs_is_data_reloc_root(inode->root))
+ return false;
+
cache = btrfs_lookup_block_group(fs_info, start);
ASSERT(cache);
if (!cache)