Messages in this thread Patch in this message | | | From | Naohiro Aota <> | Subject | [RFC PATCH 05/17] btrfs: disable fallocate in HMZONED mode | Date | Fri, 10 Aug 2018 03:04:38 +0900 |
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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 HMZONED mode.
Signed-off-by: Naohiro Aota <naota@elisp.net> --- fs/btrfs/file.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index 095f0bb86bb7..6f4546ccb57d 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -2993,6 +2993,10 @@ static long btrfs_fallocate(struct file *file, int mode, alloc_end = round_up(offset + len, blocksize); cur_offset = alloc_start; + /* Do not allow fallocate in HMZONED mode */ + if (btrfs_fs_incompat(btrfs_sb(inode->i_sb), HMZONED)) + return -EOPNOTSUPP; + /* Make sure we aren't being give some crap mode */ if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) -- 2.18.0
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