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| author | Kusanagi Kouichi <slash@ac.auone-net.jp> | 2013-01-14 16:26:52 +0100 |
|---|---|---|
| committer | Stefan Hajnoczi <stefanha@redhat.com> | 2013-01-15 10:03:47 +0100 |
| commit | 3d4fa43e648f3b169e7ab5dd4e21312e510805d7 (patch) | |
| tree | ec75aff5ec9aeea3c1e27b7b97cd57eb854383d4 /block/raw-posix.c | |
| parent | 029d091e4975af60ff9622717af19c5910f2f4e9 (diff) | |
| download | qemu-3d4fa43e648f3b169e7ab5dd4e21312e510805d7.tar.gz | |
raw-posix: support discard on more filesystems
Linux 2.6.38 introduced the filesystem independent interface to
deallocate part of a file. As of Linux 3.7, btrfs, ext4, ocfs2,
tmpfs and xfs support it.
Even though the system calls here are in practice issued on Linux,
the code is structured to allow plugging in alternatives for other Unix
variants. EOPNOTSUPP is used unconditionally in this patch, but it is
supported in both OpenBSD and Mac OS X since forever (see for example
http://lists.debian.org/debian-glibc/2006/02/msg00337.html).
Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block/raw-posix.c')
| -rw-r--r-- | block/raw-posix.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/block/raw-posix.c b/block/raw-posix.c index c3d7fda7b7..e8d79afe5f 100644 --- a/block/raw-posix.c +++ b/block/raw-posix.c @@ -59,6 +59,9 @@ #ifdef CONFIG_FIEMAP #include <linux/fiemap.h> #endif +#ifdef CONFIG_FALLOCATE_PUNCH_HOLE +#include <linux/falloc.h> +#endif #if defined (__FreeBSD__) || defined(__FreeBSD_kernel__) #include <sys/disk.h> #include <sys/cdio.h> @@ -1074,15 +1077,34 @@ static int xfs_discard(BDRVRawState *s, int64_t sector_num, int nb_sectors) static coroutine_fn int raw_co_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors) { -#ifdef CONFIG_XFS + int ret = -EOPNOTSUPP; + +#if defined(CONFIG_FALLOCATE_PUNCH_HOLE) || defined(CONFIG_XFS) BDRVRawState *s = bs->opaque; +#ifdef CONFIG_XFS if (s->is_xfs) { return xfs_discard(s, sector_num, nb_sectors); } #endif - return 0; +#ifdef CONFIG_FALLOCATE_PUNCH_HOLE + do { + if (fallocate(s->fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, + sector_num << BDRV_SECTOR_BITS, + (int64_t)nb_sectors << BDRV_SECTOR_BITS) == 0) { + return 0; + } + } while (errno == EINTR); + + ret = -errno; +#endif +#endif + + if (ret == -EOPNOTSUPP) { + return 0; + } + return ret; } static QEMUOptionParameter raw_create_options[] = { |