search for: full_zero

...ata_zero, diff --git a/plugins/full/full.c b/plugins/full/full.c index 9cfbcfcd..0b69a8c9 100644 --- a/plugins/full/full.c +++ b/plugins/full/full.c @@ -129,13 +129,10 @@ full_pwrite (void *handle, const void *buf, uint32_t count, uint64_t offset, return -1; } -/* Write zeroes. */ -static int -full_zero (void *handle, uint32_t count, uint64_t offset, uint32_t flags) -{ - errno = ENOSPC; - return -1; -} +/* Omitting full_zero is intentional: that way, nbdkit defaults to + * permitting fast zeroes which respond with ENOTSUP, while normal + * zeroes fall back to pwrite and respond with ENOSPC. + */...

This is a cover letter to a series of patches being proposed in tandem to four different projects: - nbd: Document a new NBD_CMD_FLAG_FAST_ZERO command flag - qemu: Implement the flag for both clients and server - libnbd: Implement the flag for clients - nbdkit: Implement the flag for servers, including the nbd passthrough client If you want to test the patches together, I've pushed a

I'm still working my way through the filters before this series will be complete, but this is enough of a start to at least get some feedback on the idea of implementing another NBD protocol extension. Eric Blake (9): server: Internal hooks for implementing NBD_CMD_CACHE plugins: Add .cache callback file, split: Implement .cache with posix_fadvise nbd: Implement NBD_CMD_CACHE

Since v1: - rework .can_cache to be tri-state, with default of no advertisement (ripple effect through other patches) - add a lot more patches in order to round out filter support And in the meantime, Rich pushed NBD_CMD_CACHE support into libnbd, so in theory we now have a way to test cache commands through the entire stack. Eric Blake (24): server: Internal hooks for implementing