On 6/12/20 10:06 AM, fdmanana@xxxxxxxxxx wrote:
From: Filipe Manana <fdmanana@xxxxxxxx>
This test currently always fails on btrfs:
generic/471 2s ... - output mismatch (see ...results//generic/471.out.bad)
--- tests/generic/471.out 2020-06-10 19:29:03.850519863 +0100
+++ /home/fdmanana/git/hub/xfstests/results//generic/471.out.bad ...
@@ -2,12 +2,10 @@
pwrite: Resource temporarily unavailable
wrote 8388608/8388608 bytes at offset 0
XXX Bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
-RWF_NOWAIT time is within limits.
+pwrite: Resource temporarily unavailable
+(standard_in) 1: syntax error
+RWF_NOWAIT took seconds
This is because btrfs is a COW filesystem and an attempt to write into a
previously written file range allocating a new extent (or multiple).
The only exceptions are when attempting to write to a file range with a
preallocated/unwritten extent or when writing to a NOCOW file that has
extents allocated in the target range already.
The test currently expects that writing into a previously written file
range succeeds, but that is not true on btrfs since we are not dealing
with a NOCOW file. So to make the test pass on btrfs, set the NOCOW bit
on the file when the filesystem is btrfs.
Signed-off-by: Filipe Manana <fdmanana@xxxxxxxx>
Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
Thanks,
Josef
