From f1569c4c10a1e9320b92486d73043c6138859cc5 Mon Sep 17 00:00:00 2001 From: Naohiro Aota Date: Tue, 10 Nov 2020 20:26:12 +0900 Subject: [PATCH] btrfs: disable fallocate in ZONED mode fallocate() is implemented by reserving actual extent instead of reservations. This can result in exposing the sequential write constraint of host-managed zoned block devices to the application, which would break the POSIX semantic for the fallocated file. To avoid this, report fallocate() as not supported when in ZONED mode for now. In the future, we may be able to implement "in-memory" fallocate() in ZONED mode by utilizing space_info->bytes_may_use or similar, so this returns EOPNOTSUPP. Reviewed-by: Johannes Thumshirn Reviewed-by: Josef Bacik Reviewed-by: Anand Jain Signed-off-by: Naohiro Aota Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/file.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index d808928dded6..0e41459b8de6 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -3308,6 +3308,10 @@ static long btrfs_fallocate(struct file *file, int mode, int blocksize = btrfs_inode_sectorsize(BTRFS_I(inode)); int ret; + /* Do not allow fallocate in ZONED mode */ + if (btrfs_is_zoned(btrfs_sb(inode->i_sb))) + return -EOPNOTSUPP; + alloc_start = round_down(offset, blocksize); alloc_end = round_up(offset + len, blocksize); cur_offset = alloc_start;