diff options
| -rw-r--r-- | module/zfs/zvol.c | 19 |
1 files changed, 12 insertions, 7 deletions
diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c index 074ec51e6..492f8ff87 100644 --- a/module/zfs/zvol.c +++ b/module/zfs/zvol.c @@ -650,14 +650,19 @@ zvol_discard(struct bio *bio) return (SET_ERROR(EIO)); /* - * Align the request to volume block boundaries. If we don't, - * then this will force dnode_free_range() to zero out the - * unaligned parts, which is slow (read-modify-write) and - * useless since we are not freeing any space by doing so. - * XXX: We should handle secure discard by zeroing out unaligned parts. + * Align the request to volume block boundaries when REQ_SECURE is + * available, but not requested. If we don't, then this will force + * dnode_free_range() to zero out the unaligned parts, which is slow + * (read-modify-write) and useless since we are not freeing any space + * by doing so. Kernels that do not support REQ_SECURE (2.6.32 through + * 2.6.35) will not receive this optimization. */ - start = P2ROUNDUP(start, zv->zv_volblocksize); - end = P2ALIGN(end, zv->zv_volblocksize); +#ifdef REQ_SECURE + if (!(bio->bi_rw & REQ_SECURE)) { + start = P2ROUNDUP(start, zv->zv_volblocksize); + end = P2ALIGN(end, zv->zv_volblocksize); + } +#endif if (start >= end) return (0); |