search for: truncate_pwrite

...-1; + } + } + nbdkit_extents_free (extents2); + + return 0; +} + static struct nbdkit_filter filter = { .name = "truncate", .longname = "nbdkit truncate filter", @@ -297,6 +351,7 @@ static struct nbdkit_filter filter = { .pwrite = truncate_pwrite, .trim = truncate_trim, .zero = truncate_zero, + .extents = truncate_extents, }; NBDKIT_REGISTER_FILTER(filter) -- 2.20.1

...const char *buffer, size_t size) +{ + size_t i; + const size_t limit = size < 16 ? size : 16; + + for (i = 0; i < limit; ++i) + if (buffer[i]) + return 0; + if (size != limit) + return !memcmp (buffer, buffer + 16, size - 16); + + return 1; +} + +/* Write data. */ +static int +truncate_pwrite (struct nbdkit_next_ops *next_ops, void *nxdata, + void *handle, + const void *buf, uint32_t count, uint64_t offset, + uint32_t flags, int *err) +{ + int r; + uint32_t n; + + if (offset < real_size) { + if (offset + count <= real_size) +...

...uint32_t n; - uint64_t real_size_copy; - - pthread_mutex_lock (&lock); - real_size_copy = real_size; - pthread_mutex_unlock (&lock); + uint64_t real_size_copy = get_real_size (); if (offset < real_size_copy) { if (offset + count <= real_size_copy) @@ -209,11 +210,7 @@ truncate_pwrite (struct nbdkit_next_ops *next_ops, void *nxdata, { int r; uint32_t n; - uint64_t real_size_copy; - - pthread_mutex_lock (&lock); - real_size_copy = real_size; - pthread_mutex_unlock (&lock); + uint64_t real_size_copy = get_real_size (); if (offset < real_size_copy) {...

...n = count; + else + n = real_size_copy - offset; + r = next_ops->pread (nxdata, buf, n, offset, flags, err); + if (r == -1) + return -1; + count -= n; + buf += n; + } + + if (count > 0) + memset (buf, 0, count); + + return 0; +} + +/* Write data. */ +static int +truncate_pwrite (struct nbdkit_next_ops *next_ops, void *nxdata, + void *handle, + const void *buf, uint32_t count, uint64_t offset, + uint32_t flags, int *err) +{ + int r; + uint32_t n; + uint64_t real_size_copy; + + pthread_mutex_lock (&lock); + real_size_...

...set < h->real_size) { + if (offset + count <= h->real_size) n = count; else - n = real_size_copy - offset; + n = h->real_size - offset; r = next_ops->pread (nxdata, buf, n, offset, flags, err); if (r == -1) return -1; @@ -209,17 +235,13 @@ truncate_pwrite (struct nbdkit_next_ops *next_ops, void *nxdata, { int r; uint32_t n; - uint64_t real_size_copy; + struct handle *h = handle; - pthread_mutex_lock (&lock); - real_size_copy = real_size; - pthread_mutex_unlock (&lock); - - if (offset < real_size_copy) { - if (offset + cou...

While working on adding assertions to pthread_mutex_lock calls, I noticed that the truncate filter's use of mutex didn't really protect us, and isn't really necessary. Cleaning that up also spotted a couple of other potential cleanups. Eric Blake (4): filters: Drop useless .open callbacks truncate: Fix corruption when plugin changes per-connection size truncate: Test for safe

...-426,6 +438,7 @@ static struct nbdkit_filter filter = { .prepare = truncate_prepare, .get_size = truncate_get_size, .can_fast_zero = truncate_can_fast_zero, + .init_sparse = truncate_init_sparse, .pread = truncate_pread, .pwrite = truncate_pwrite, .trim = truncate_trim, diff --git a/include/nbdkit-filter.h b/include/nbdkit-filter.h index 3500317..d327bf8 100644 --- a/include/nbdkit-filter.h +++ b/include/nbdkit-filter.h @@ -1,5 +1,5 @@ /* nbdkit - * Copyright (C) 2013-2019 Red Hat Inc. + * Copyright (C) 2013-2020 Red Hat In...

I do have a question about whether patch 2 is right, or whether I've exposed a bigger problem in the truncate (and possibly other) filter, but the rest seem fairly straightforward. Eric Blake (4): server: Check for pthread lock failures truncate: Factor out reading real_size under mutex plugins: Check for mutex failures filters: Check for mutex failures filters/cache/cache.c

I have dropped the map filter from this series for now while I try to get it working. However I think the truncate filter is in a good shape. This incorporates all feedback from Eric's review. Also there are three small fixes to the filter code, all revealed when I was testing using multiple filters which we'd not done much of before. Rich.

This patch series proposes two new filters. * truncate: This can truncate, extend, round up or round down the size of a plugin/device. A typical usage is to fix the qemu problem that it can only handle devices which are a multiple of 512-bytes: nbdkit --filter=truncate random size=500 round-up=512 This will serve a virtual device with size 512 bytes. Reading from the last 12 bytes will

I'm not sure exactly which version we're up to, but let's say it's version 4. I'm a lot happier with this version: - all filters have been reviewed and changed where I think that's necessary - can_extents is properly defined and implemented now - NBD protocol is followed - I believe it addresses all previous review points where possible The "only" thing

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

This has already been pushed upstream. I am simply posting these here so we have a reference in the mailing list in case we find bugs later (as I'm sure we will - it's a complex patch series). Great thanks to Eric Blake for tireless review on this one. It also seems to have identified a few minor bugs in qemu along the way. Rich.

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