All of lore.kernel.org
 help / color / mirror / Atom feed
From: Kevin Wolf <kwolf@redhat.com>
To: qemu-block@nongnu.org
Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org
Subject: [PULL 08/15] file-posix: Support BDRV_REQ_ZERO_WRITE for truncate
Date: Thu, 30 Apr 2020 17:52:24 +0200	[thread overview]
Message-ID: <20200430155231.473156-9-kwolf@redhat.com> (raw)
In-Reply-To: <20200430155231.473156-1-kwolf@redhat.com>

For regular files, we always get BDRV_REQ_ZERO_WRITE behaviour from the
OS, so we can advertise the flag and just ignore it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20200424125448.63318-7-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/file-posix.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/block/file-posix.c b/block/file-posix.c
index 58326a0a60..bf09ad8bc0 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -702,6 +702,10 @@ static int raw_open_common(BlockDriverState *bs, QDict *options,
 #endif
 
     bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK;
+    if (S_ISREG(st.st_mode)) {
+        /* When extending regular files, we get zeros from the OS */
+        bs->supported_truncate_flags = BDRV_REQ_ZERO_WRITE;
+    }
     ret = 0;
 fail:
     if (filename && (bdrv_flags & BDRV_O_TEMPORARY)) {
-- 
2.25.3



  parent reply	other threads:[~2020-04-30 16:05 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-30 15:52 [PULL 00/15] Block layer patches Kevin Wolf
2020-04-30 15:52 ` [PULL 01/15] qcow2: Add incompatibility note between backing files and raw external data files Kevin Wolf
2020-04-30 15:52 ` [PULL 02/15] qemu-iotests: allow qcow2 external discarded clusters to contain stale data Kevin Wolf
2020-04-30 15:52 ` [PULL 03/15] block: Add flags to BlockDriver.bdrv_co_truncate() Kevin Wolf
2020-04-30 15:52 ` [PULL 04/15] block: Add flags to bdrv(_co)_truncate() Kevin Wolf
2020-04-30 15:52 ` [PULL 05/15] block-backend: Add flags to blk_truncate() Kevin Wolf
2020-04-30 15:52 ` [PULL 06/15] qcow2: Support BDRV_REQ_ZERO_WRITE for truncate Kevin Wolf
2020-04-30 15:52 ` [PULL 07/15] raw-format: " Kevin Wolf
2020-04-30 15:52 ` Kevin Wolf [this message]
2020-04-30 15:52 ` [PULL 09/15] block: truncate: Don't make backing file data visible Kevin Wolf
2020-04-30 15:52 ` [PULL 10/15] iotests: Filter testfiles out in filter_img_info() Kevin Wolf
2020-04-30 15:52 ` [PULL 11/15] iotests: Test committing to short backing file Kevin Wolf
2020-04-30 15:52 ` [PULL 12/15] qcow2: Forward ZERO_WRITE flag for full preallocation Kevin Wolf
2020-04-30 15:52 ` [PULL 13/15] nvme: introduce PMR support from NVMe 1.4 spec Kevin Wolf
2020-04-30 15:52 ` [PULL 14/15] qom: Factor out user_creatable_add_dict() Kevin Wolf
2020-04-30 15:52 ` [PULL 15/15] qemu-storage-daemon: Fix non-string --object properties Kevin Wolf
2020-05-01  9:27 ` [PULL 00/15] Block layer patches Peter Maydell

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200430155231.473156-9-kwolf@redhat.com \
    --to=kwolf@redhat.com \
    --cc=peter.maydell@linaro.org \
    --cc=qemu-block@nongnu.org \
    --cc=qemu-devel@nongnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.