search for: null_pread

...conditions are @@ -107,6 +107,20 @@ null_can_fast_zero (void *handle) return 1; } +/* Always sparse. */ +static int +null_init_sparse (void *handle) +{ + return 1; +} + +/* Always reads as zero. */ +static int +null_init_zero (void *handle) +{ + return 1; +} + /* Read data. */ static int null_pread (void *handle, void *buf, uint32_t count, uint64_t offset, @@ -175,6 +189,8 @@ static struct nbdkit_plugin plugin = { .can_multi_conn = null_can_multi_conn, .can_cache = null_can_cache, .can_fast_zero = null_can_fast_zero, + .init_sparse = null_init_sparse, + .init_z...

.../null/null.c index 647624ba..559cb815 100644 --- a/plugins/null/null.c +++ b/plugins/null/null.c @@ -100,6 +100,13 @@ null_can_cache (void *handle) return NBDKIT_CACHE_NATIVE; } +/* Fast zero. */ +static int +null_can_fast_zero (void *handle) +{ + return 1; +} + /* Read data. */ static int null_pread (void *handle, void *buf, uint32_t count, uint64_t offset, @@ -167,6 +174,7 @@ static struct nbdkit_plugin plugin = { .get_size = null_get_size, .can_multi_conn = null_can_multi_conn, .can_cache = null_can_cache, + .can_fast_zero = null_can_fast_zero, .pread...

I will be following up to this email with four separate threads each addressed to the appropriate single list, with proposed changes to: - the NBD protocol - qemu: both server and client - libnbd: client - nbdkit: server The feature in question adds a new optional NBD_INFO_ packet to the NBD_OPT_GO portion of handshake, adding up to 16 bits of information that the server can advertise to the

After more than a month since v2 [1], I've finally got my FUA support series polished. This is all of my outstanding patches, even though some of them were originally posted in separate threads from the original FUA post [2], [3] [1] https://www.redhat.com/archives/libguestfs/2018-January/msg00113.html [2] https://www.redhat.com/archives/libguestfs/2018-January/msg00219.html [3]

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

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