[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH 7/8] block/raw-posix: call plain fallocate in handle
From: |
Denis V. Lunev |
Subject: |
[Qemu-devel] [PATCH 7/8] block/raw-posix: call plain fallocate in handle_aiocb_write_zeroes |
Date: |
Tue, 30 Dec 2014 12:20:49 +0300 |
There is a possibility that we are extending our image and thus writing
zeroes beyond end of the file. In this case we do not need to care
about the hole to make sure that there is no data in the file under
this offset (pre-condition to fallocate(0) to work). We could simply call
fallocate(0).
This improves the performance of writing zeroes even on really old
platforms which do not have even FALLOC_FL_PUNCH_HOLE.
Signed-off-by: Denis V. Lunev <address@hidden>
CC: Kevin Wolf <address@hidden>
CC: Stefan Hajnoczi <address@hidden>
CC: Peter Lieven <address@hidden>
---
block/raw-posix.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/block/raw-posix.c b/block/raw-posix.c
index 96a8678..57b94ad 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -60,7 +60,7 @@
#define FS_NOCOW_FL 0x00800000 /* Do not cow file */
#endif
#endif
-#if defined(CONFIG_FALLOCATE_PUNCH_HOLE) ||
defined(CONFIG_FALLOCATE_ZERO_RANGE)
+#ifdef CONFIG_FALLOCATE
#include <linux/falloc.h>
#endif
#if defined (__FreeBSD__) || defined(__FreeBSD_kernel__)
@@ -903,7 +903,7 @@ static int translate_err(int err)
return err;
}
-#if defined(CONFIG_FALLOCATE_PUNCH_HOLE) ||
defined(CONFIG_FALLOCATE_ZERO_RANGE)
+#ifdef CONFIG_FALLOCATE
static int do_fallocate(int fd, int mode, off_t offset, off_t len)
{
do {
@@ -957,6 +957,12 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData
*aiocb)
s = aiocb->bs->opaque;
+#ifdef CONFIG_FALLOCATE
+ if (aiocb->aio_offset >= aiocb->bs->total_sectors << BDRV_SECTOR_BITS) {
+ return do_fallocate(s->fd, 0, aiocb->aio_offset, aiocb->aio_nbytes);
+ }
+#endif
+
#ifdef CONFIG_FALLOCATE_ZERO_RANGE
if (s->has_write_zeroes) {
int ret = do_fallocate(s->fd, FALLOC_FL_ZERO_RANGE,
--
1.9.1
- [Qemu-devel] [PATCH v3 0/8] eliminate data write in bdrv_write_zeroes on Linux in raw-posix.c, Denis V. Lunev, 2014/12/30
- [Qemu-devel] [PATCH 8/8] block/raw-posix: set max_write_zeroes to INT_MAX for regular files, Denis V. Lunev, 2014/12/30
- [Qemu-devel] [PATCH 7/8] block/raw-posix: call plain fallocate in handle_aiocb_write_zeroes,
Denis V. Lunev <=
- [Qemu-devel] [PATCH 1/8] block: prepare bdrv_co_do_write_zeroes to deal with large bl.max_write_zeroes, Denis V. Lunev, 2014/12/30
- [Qemu-devel] [PATCH 5/8] block/raw-posix: refactor handle_aiocb_write_zeroes a bit, Denis V. Lunev, 2014/12/30
- [Qemu-devel] [PATCH 6/8] block: use fallocate(FALLOC_FL_PUNCH_HOLE) & fallocate(0) to write zeroes, Denis V. Lunev, 2014/12/30
- [Qemu-devel] [PATCH 2/8] block: use fallocate(FALLOC_FL_ZERO_RANGE) in handle_aiocb_write_zeroes, Denis V. Lunev, 2014/12/30
- [Qemu-devel] [PATCH 3/8] block/raw-posix: create do_fallocate helper, Denis V. Lunev, 2014/12/30
- [Qemu-devel] [PATCH 4/8] block/raw-posix: create translate_err helper to merge errno values, Denis V. Lunev, 2014/12/30
- Re: [Qemu-devel] [PATCH v3 0/8] eliminate data write in bdrv_write_zeroes on Linux in raw-posix.c, Peter Lieven, 2014/12/30