[PATCH 5.15 09/20] btrfs: check for relocation inodes on zoned btrfs in should_nocow

From: Greg Kroah-Hartman
Date: Fri Nov 19 2021 - 12:40:47 EST


From: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>

commit 2adada886b26e998b5a624e72f0834ebfdc54cc7 upstream

Prepare for allowing preallocation for relocation inodes.

Reviewed-by: Naohiro Aota <naohiro.aota@xxxxxxx>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Reviewed-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/btrfs/inode.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1945,7 +1945,15 @@ int btrfs_run_delalloc_range(struct btrf
const bool zoned = btrfs_is_zoned(inode->root->fs_info);

if (should_nocow(inode, start, end)) {
- ASSERT(!zoned);
+ /*
+ * Normally on a zoned device we're only doing COW writes, but
+ * in case of relocation on a zoned filesystem we have taken
+ * precaution, that we're only writing sequentially. It's safe
+ * to use run_delalloc_nocow() here, like for regular
+ * preallocated inodes.
+ */
+ ASSERT(!zoned ||
+ (zoned && btrfs_is_data_reloc_root(inode->root)));
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, nr_written);
} else if (!inode_can_compress(inode) ||