| Message ID | cover.1599759873.git.berto@igalia.com |
|---|---|
| Headers | show |
| Series | Skip copy-on-write when allocating a zero cluster | expand |
11.09.2020 13:04, Alberto Garcia wrote: > On Fri 11 Sep 2020 11:34:37 AM CEST, Vladimir Sementsov-Ogievskiy wrote: >>> - if (!is_zero_cow(bs, m)) { >>> + ret = is_zero_cow(bs, m); >>> + if (ret < 0) { >>> + return ret; >> >> It's a common practice to treat block-status errors as "unknown" >> status and not error-out immediately: >> >> - really, it's not critical, we can continue assuming non-zero >> - if there are real problems with IO, we'll most probably fail on >> real read or write operation, and report its status, which seems >> better for user than block-status error > > But what's the problem exactly, does this complicate the code too much? > :-? Of course not :) Hmm. OK, I don't know, I'm just used to this practice in block jobs. Patch is correct as is: Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> > >> So, I'd keep existing logic in handle_alloc_space(). And, if you agree >> and resend, probably good to split this patch into two, one for >> block.h/io.c and one for qcow2.c (still, I'm OK with it as one patch). > > Sure, I can split the patch if I have to resend it. > > Berto >
Here's the new version, there are two patches this time. Berto v3: - Add a new patch to improve the reporting of BDRV_BLOCK_ZERO [Vladimir] - Rename function to bdrv_co_is_zero_fast() [Vladimir, Kevin] - Don't call bdrv_common_block_status_above() if bytes == 0 v2: https://lists.gnu.org/archive/html/qemu-block/2020-08/msg01165.html - Add new, simpler API: bdrv_is_unallocated_or_zero_above() v1: https://lists.gnu.org/archive/html/qemu-block/2020-08/msg00403.html Alberto Garcia (2): qcow2: Report BDRV_BLOCK_ZERO more accurately in bdrv_co_block_status() qcow2: Skip copy-on-write when allocating a zero cluster include/block/block.h | 2 ++ block/io.c | 35 +++++++++++++++++++++++++++++++---- block/qcow2.c | 35 +++++++++++++++++++---------------- 3 files changed, 52 insertions(+), 20 deletions(-)