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| author | mm <mm@FreeBSD.org> | 2012-11-25 16:32:07 +0000 |
|---|---|---|
| committer | mm <mm@FreeBSD.org> | 2012-11-25 16:32:07 +0000 |
| commit | 3a0bfecf052237768517963f169d0797e2978f59 (patch) | |
| tree | 35856bc2042e24d142ce48d78e222231eeb62646 /sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c | |
| parent | 081fe7e2837cd17182c14d95cfe3d9cf8b82e05d (diff) | |
| download | FreeBSD-src-3a0bfecf052237768517963f169d0797e2978f59.zip FreeBSD-src-3a0bfecf052237768517963f169d0797e2978f59.tar.gz | |
MFV r243013 and r243267:
Import the zio nop-write improvement from Illumos. To reduce I/O,
nop-write omits overwriting data if the checksum (cryptographically
secure) of new data matches the checksum of existing data.
It also saves space if snapshots are in use.
It currently works only on datasets with enabled compression, disabled
deduplication and sha256 checksums.
IllumOS 13887:196932ec9e6a and 13888:7204b3392a58
3236 zio nop-write
References:
https://www.illumos.org/issues/3236
MFC after: 2 weeks
Diffstat (limited to 'sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c')
| -rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c index 07fd3c6..e5d159b 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zvol.c @@ -78,6 +78,7 @@ #include <sys/vdev_impl.h> #include <sys/zvol.h> #include <sys/zil_impl.h> +#include <sys/dbuf.h> #include <geom/geom.h> #include "zfs_namecheck.h" @@ -1051,6 +1052,12 @@ zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio) error = dmu_buf_hold(os, object, offset, zgd, &db, DMU_READ_NO_PREFETCH); if (error == 0) { + blkptr_t *obp = dmu_buf_get_blkptr(db); + if (obp) { + ASSERT(BP_IS_HOLE(bp)); + *bp = *obp; + } + zgd->zgd_db = db; zgd->zgd_bp = bp; |
