search for: next_can_multi_conn

...} + *flags = eflags; return 0; } diff --git a/server/filters.c b/server/filters.c index d02e7fb..5b7abc4 100644 --- a/server/filters.c +++ b/server/filters.c @@ -316,6 +316,13 @@ next_can_fua (void *nxdata) return b_conn->b->can_fua (b_conn->b, b_conn->conn); } +static int +next_can_multi_conn (void *nxdata) +{ + struct b_conn *b_conn = nxdata; + return b_conn->b->can_multi_conn (b_conn->b, b_conn->conn); +} + static int next_pread (void *nxdata, void *buf, uint32_t count, uint64_t offset, uint32_t flags, int *err) @@ -365,6 +372,7 @@ static struct nbdkit_nex...

...backend_can_fast_zero (b_next); -} - -static int -next_can_extents (void *nxdata) -{ - struct backend *b_next = nxdata; - return backend_can_extents (b_next); -} - -static int -next_can_fua (void *nxdata) -{ - struct backend *b_next = nxdata; - return backend_can_fua (b_next); -} - -static int -next_can_multi_conn (void *nxdata) -{ - struct backend *b_next = nxdata; - return backend_can_multi_conn (b_next); -} - -static int -next_can_cache (void *nxdata) -{ - struct backend *b_next = nxdata; - return backend_can_cache (b_next); -} - -static int -next_pread (void *nxdata, void *buf, uint32_t count, uint64...

First thing to say is that I need to do a *lot* more testing on this, so this is just an early peek. In particular, although it passed ‘make check && make check-valgrind’ I have *not* tested it against a multi-conn-aware client such as the Linux kernel >= 4.9. This implements NBD_FLAG_CAN_MULTI_CONN, described in the protocol doc as: "NBD_FLAG_CAN_MULTI_CONN: Indicates that

For existing commits, this is almost identical to v1, except that I updated some commit messages and reordered the commits in a somewhat more logical sequence. The main changes are the extra commits: [06/11] plugins: Return NBD_FLAG_CAN_MULTI_CONN from some readonly plugins. - Readonly plugins that can set the flag unconditionally. [09/11] partitioning: Return NBD_FLAG_CAN_MULTI_CONN. [10/11]

...extents (void *nxdata) { @@ -442,6 +449,7 @@ static struct nbdkit_next_ops next_ops = { .is_rotational = next_is_rotational, .can_trim = next_can_trim, .can_zero = next_can_zero, + .can_sr = next_can_sr, .can_extents = next_can_extents, .can_fua = next_can_fua, .can_multi_conn = next_can_multi_conn, @@ -586,6 +594,21 @@ filter_can_zero (struct backend *b, struct connection *conn) return f->backend.next->can_zero (f->backend.next, conn); } +static int +filter_can_sr (struct backend *b, struct connection *conn) +{ + struct backend_filter *f = container_of (b, struct backend_fil...

...ze = next_get_size, .can_write = next_can_write, @@ -371,6 +388,7 @@ static struct nbdkit_next_ops next_ops = { .is_rotational = next_is_rotational, .can_trim = next_can_trim, .can_zero = next_can_zero, + .can_extents = next_can_extents, .can_fua = next_can_fua, .can_multi_conn = next_can_multi_conn, .pread = next_pread, @@ -378,6 +396,7 @@ static struct nbdkit_next_ops next_ops = { .flush = next_flush, .trim = next_trim, .zero = next_zero, + .extents = next_extents, }; static int @@ -511,6 +530,21 @@ filter_can_zero (struct backend *b, struct connection *conn) return f-&...

...nts (b_h->b); + struct backend *b_next = nxdata; + return backend_can_extents (b_next); } static int next_can_fua (void *nxdata) { - struct b_h *b_h = nxdata; - return backend_can_fua (b_h->b); + struct backend *b_next = nxdata; + return backend_can_fua (b_next); } static int next_can_multi_conn (void *nxdata) { - struct b_h *b_h = nxdata; - return backend_can_multi_conn (b_h->b); + struct backend *b_next = nxdata; + return backend_can_multi_conn (b_next); } static int next_can_cache (void *nxdata) { - struct b_h *b_h = nxdata; - return backend_can_cache (b_h->b); + str...

...+ return backend_init_zero (b_conn->b, b_conn->conn); +} + static int next_pread (void *nxdata, void *buf, uint32_t count, uint64_t offset, uint32_t flags, int *err) @@ -407,6 +421,8 @@ static struct nbdkit_next_ops next_ops = { .can_fua = next_can_fua, .can_multi_conn = next_can_multi_conn, .can_cache = next_can_cache, + .init_sparse = next_init_sparse, + .init_zero = next_init_zero, .pread = next_pread, .pwrite = next_pwrite, .flush = next_flush, @@ -577,15 +593,25 @@ filter_can_cache (struct backend *b, struct connection *conn, void *handle) static int filter_init_s...

...ze = next_get_size, .can_write = next_can_write, @@ -371,6 +388,7 @@ static struct nbdkit_next_ops next_ops = { .is_rotational = next_is_rotational, .can_trim = next_can_trim, .can_zero = next_can_zero, + .can_extents = next_can_extents, .can_fua = next_can_fua, .can_multi_conn = next_can_multi_conn, .pread = next_pread, @@ -378,6 +396,7 @@ static struct nbdkit_next_ops next_ops = { .flush = next_flush, .trim = next_trim, .zero = next_zero, + .extents = next_extents, }; static int @@ -511,6 +530,21 @@ filter_can_zero (struct backend *b, struct connection *conn) return f-&...

...ze = next_get_size, .can_write = next_can_write, @@ -371,6 +388,7 @@ static struct nbdkit_next_ops next_ops = { .is_rotational = next_is_rotational, .can_trim = next_can_trim, .can_zero = next_can_zero, + .can_extents = next_can_extents, .can_fua = next_can_fua, .can_multi_conn = next_can_multi_conn, .pread = next_pread, @@ -378,6 +396,7 @@ static struct nbdkit_next_ops next_ops = { .flush = next_flush, .trim = next_trim, .zero = next_zero, + .extents = next_extents, }; static int @@ -511,6 +530,21 @@ filter_can_zero (struct backend *b, struct connection *conn) return f-&...

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

...ze = next_get_size, .can_write = next_can_write, @@ -371,6 +387,7 @@ static struct nbdkit_next_ops next_ops = { .is_rotational = next_is_rotational, .can_trim = next_can_trim, .can_zero = next_can_zero, + .can_extents = next_can_extents, .can_fua = next_can_fua, .can_multi_conn = next_can_multi_conn, .pread = next_pread, @@ -378,6 +395,7 @@ static struct nbdkit_next_ops next_ops = { .flush = next_flush, .trim = next_trim, .zero = next_zero, + .extents = next_extents, }; static int @@ -511,6 +529,21 @@ filter_can_zero (struct backend *b, struct connection *conn) return f-&...

This tentative commit implements extents/can_extents, roughly as discussed in the previous thread here: https://www.redhat.com/archives/libguestfs/2019-March/msg00017.html I can't say that I'm a big fan of having the plugin allocate an extents array. There are no other plugin callbacks currently where we require the plugin to allocate complex data structures (or indeed do any allocation

...ze = next_get_size, .can_write = next_can_write, @@ -371,6 +387,7 @@ static struct nbdkit_next_ops next_ops = { .is_rotational = next_is_rotational, .can_trim = next_can_trim, .can_zero = next_can_zero, + .can_extents = next_can_extents, .can_fua = next_can_fua, .can_multi_conn = next_can_multi_conn, .pread = next_pread, @@ -378,6 +395,7 @@ static struct nbdkit_next_ops next_ops = { .flush = next_flush, .trim = next_trim, .zero = next_zero, + .extents = next_extents, }; static int @@ -511,6 +529,21 @@ filter_can_zero (struct backend *b, struct connection *conn) return f-&...

I'm not sure which version we're up to now. Anyway I believe this addresses all the points that Eric raised in: https://www.redhat.com/archives/libguestfs/2019-March/msg00038.html https://www.redhat.com/archives/libguestfs/2019-March/msg00040.html In particular: - default state of extents_map is all allocated disk - support hole + non-zero - you can now iterate with bounds -

...ze = next_get_size, .can_write = next_can_write, @@ -371,6 +387,7 @@ static struct nbdkit_next_ops next_ops = { .is_rotational = next_is_rotational, .can_trim = next_can_trim, .can_zero = next_can_zero, + .can_extents = next_can_extents, .can_fua = next_can_fua, .can_multi_conn = next_can_multi_conn, .pread = next_pread, @@ -378,6 +395,7 @@ static struct nbdkit_next_ops next_ops = { .flush = next_flush, .trim = next_trim, .zero = next_zero, + .extents = next_extents, }; static int @@ -511,6 +529,21 @@ filter_can_zero (struct backend *b, struct connection *conn) return f-&...

Second version based on nbdkit_extent* calls, as discussed here: https://www.redhat.com/archives/libguestfs/2019-March/msg00033.html Note in particular there is some subtlety about how filters would work in this implementation. See docs/nbdkit-filter.pod for the details. Rich.

...ze = next_get_size, .can_write = next_can_write, @@ -371,6 +388,7 @@ static struct nbdkit_next_ops next_ops = { .is_rotational = next_is_rotational, .can_trim = next_can_trim, .can_zero = next_can_zero, + .can_extents = next_can_extents, .can_fua = next_can_fua, .can_multi_conn = next_can_multi_conn, .pread = next_pread, @@ -378,6 +396,7 @@ static struct nbdkit_next_ops next_ops = { .flush = next_flush, .trim = next_trim, .zero = next_zero, + .extents = next_extents, }; static int @@ -511,6 +530,21 @@ filter_can_zero (struct backend *b, struct connection *conn) return f-&...

It's confusing to use the same terminology for a single backend as for the linked list of backends. In particular it's often not clear if we're calling the next backend or the whole chain of backends. --- server/internal.h | 14 ++++++++++-- server/connections.c | 20 ++++++++--------- server/locks.c | 2 +- server/main.c

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