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| author | Denis V. Lunev <den@openvz.org> | 2015-01-30 11:42:14 +0300 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2015-02-06 17:24:20 +0100 |
| commit | b953f075007a7860adce9fa410b2e116a3d5e29c (patch) | |
| tree | a74183d720dfb65c01b65fc9acd93c9939f11f2e | |
| parent | 37cc9f7f684ed035da63274daca1594c7ee16213 (diff) | |
| download | qemu-b953f075007a7860adce9fa410b2e116a3d5e29c.zip qemu-b953f075007a7860adce9fa410b2e116a3d5e29c.tar.gz qemu-b953f075007a7860adce9fa410b2e116a3d5e29c.tar.bz2 | |
block: use fallocate(FALLOC_FL_ZERO_RANGE) in handle_aiocb_write_zeroes
This efficiently writes zeroes on Linux if the kernel is capable enough.
FALLOC_FL_ZERO_RANGE correctly handles all cases, including and not
including file expansion.
CC: Kevin Wolf <kwolf@redhat.com>
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Peter Lieven <pl@kamp.de>
CC: Fam Zheng <famz@redhat.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
| -rw-r--r-- | block/raw-posix.c | 15 | ||||
| -rwxr-xr-x | configure | 19 |
2 files changed, 32 insertions, 2 deletions
diff --git a/block/raw-posix.c b/block/raw-posix.c index d3910fd..5a777e7 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 -#ifdef CONFIG_FALLOCATE_PUNCH_HOLE +#if defined(CONFIG_FALLOCATE_PUNCH_HOLE) || defined(CONFIG_FALLOCATE_ZERO_RANGE) #include <linux/falloc.h> #endif #if defined (__FreeBSD__) || defined(__FreeBSD_kernel__) @@ -902,7 +902,7 @@ static int translate_err(int err) return err; } -#if defined(CONFIG_FALLOCATE_PUNCH_HOLE) +#if defined(CONFIG_FALLOCATE_PUNCH_HOLE) || defined(CONFIG_FALLOCATE_ZERO_RANGE) static int do_fallocate(int fd, int mode, off_t offset, off_t len) { do { @@ -954,6 +954,17 @@ static ssize_t handle_aiocb_write_zeroes(RawPosixAIOData *aiocb) } #endif +#ifdef CONFIG_FALLOCATE_ZERO_RANGE + if (s->has_write_zeroes) { + int ret = do_fallocate(s->fd, FALLOC_FL_ZERO_RANGE, + aiocb->aio_offset, aiocb->aio_nbytes); + if (ret == 0 || ret != -ENOTSUP) { + return ret; + } + s->has_write_zeroes = false; + } +#endif + return -ENOTSUP; } @@ -3335,6 +3335,22 @@ if compile_prog "" "" ; then fallocate_punch_hole=yes fi +# check that fallocate supports range zeroing inside the file +fallocate_zero_range=no +cat > $TMPC << EOF +#include <fcntl.h> +#include <linux/falloc.h> + +int main(void) +{ + fallocate(0, FALLOC_FL_ZERO_RANGE, 0, 0); + return 0; +} +EOF +if compile_prog "" "" ; then + fallocate_zero_range=yes +fi + # check for posix_fallocate posix_fallocate=no cat > $TMPC << EOF @@ -4567,6 +4583,9 @@ fi if test "$fallocate_punch_hole" = "yes" ; then echo "CONFIG_FALLOCATE_PUNCH_HOLE=y" >> $config_host_mak fi +if test "$fallocate_zero_range" = "yes" ; then + echo "CONFIG_FALLOCATE_ZERO_RANGE=y" >> $config_host_mak +fi if test "$posix_fallocate" = "yes" ; then echo "CONFIG_POSIX_FALLOCATE=y" >> $config_host_mak fi |