search for: max_writ

...buffer; but as the buffer shouldn't be escaping, it's already undefined behavior for such code to happen). diff --git i/filters/nozero/nozero.c w/filters/nozero/nozero.c index 16ec710b..21863707 100644 --- i/filters/nozero/nozero.c +++ w/filters/nozero/nozero.c @@ -45,7 +45,6 @@ #define MAX_WRITE (64 * 1024 * 1024) -static const char buffer[MAX_WRITE]; static enum ZeroMode { NONE, EMULATE, @@ -111,6 +110,8 @@ nozero_zero (struct nbdkit_next_ops *next_ops, void *nxdata, while (count) { uint32_t size = MIN (count, MAX_WRITE); + static const char buffer[MAX_WRITE]; /* Alwa...

...-55,4 +60,4 @@ Eric Blake =head1 COPYRIGHT -Copyright (C) 2018 Red Hat Inc. +Copyright (C) 2018-2019 Red Hat Inc. diff --git a/filters/nozero/nozero.c b/filters/nozero/nozero.c index 3ec6346..6e0ffa9 100644 --- a/filters/nozero/nozero.c +++ b/filters/nozero/nozero.c @@ -47,8 +47,12 @@ #define MAX_WRITE (64 * 1024 * 1024) -static char buffer[MAX_WRITE]; -static bool emulate; +static const char buffer[MAX_WRITE]; +static enum ZeroMode { + NONE, + EMULATE, + NOTRIM, +} zeromode; static int nozero_config (nbdkit_next_config *next, void *nxdata, @@ -56,7 +60,9 @@ nozero_config (nbdkit_next_con...

Hi all, It seems GCC 9 does not put read-only zero-initialized variables into the BSS section anymore; instead it is put into RODATA. (See the thread at [0], especially [1]) In filter/nozero a 64M large, static, zeroed, read-only array is declared. The new behavior of GCC puts this array as-is into the binary inflating the size by a factor of around 10000. (Clang 8 and older GCCs work

...IT_FLAG_FUA; + } + while (count) { /* Always contains zeroes, but we can't use const or else gcc 9 * will use .rodata instead of .bss and inflate the binary size. @@ -115,7 +125,10 @@ nozero_zero (struct nbdkit_next_ops *next_ops, void *nxdata, static /* const */ char buffer[MAX_WRITE]; uint32_t size = MIN (count, MAX_WRITE); - if (next_ops->pwrite (nxdata, buffer, size, offs, flags, err) == -1) + if (size == count && need_flush) + writeflags = NBDKIT_FLAG_FUA; + + if (next_ops->pwrite (nxdata, buffer, size, offs, writeflags, err) == -1)...

...ro/nozero.c index dac47ad..6a22f9b 100644 --- a/filters/nozero/nozero.c +++ b/filters/nozero/nozero.c @@ -42,9 +42,10 @@ #include <nbdkit-filter.h> +#include "minmax.h" + #define THREAD_MODEL NBDKIT_THREAD_MODEL_PARALLEL -#define MIN(a, b) ((a) < (b) ? (a) : (b)) #define MAX_WRITE (64 * 1024 * 1024) static char buffer[MAX_WRITE]; diff --git a/plugins/pattern/pattern.c b/plugins/pattern/pattern.c index 1d1b234..32db381 100644 --- a/plugins/pattern/pattern.c +++ b/plugins/pattern/pattern.c @@ -45,6 +45,7 @@ #include <nbdkit-plugin.h> #include "byte-swapping....

...ro/nozero.c index dac47ad..6a22f9b 100644 --- a/filters/nozero/nozero.c +++ b/filters/nozero/nozero.c @@ -42,9 +42,10 @@ #include <nbdkit-filter.h> +#include "minmax.h" + #define THREAD_MODEL NBDKIT_THREAD_MODEL_PARALLEL -#define MIN(a, b) ((a) < (b) ? (a) : (b)) #define MAX_WRITE (64 * 1024 * 1024) static char buffer[MAX_WRITE]; diff --git a/plugins/pattern/pattern.c b/plugins/pattern/pattern.c index 1d1b234..32db381 100644 --- a/plugins/pattern/pattern.c +++ b/plugins/pattern/pattern.c @@ -45,6 +45,7 @@ #include <nbdkit-plugin.h> #include "byte-swapping....

Another couple things I noticed that are worth improving, but aren't strictly related to implementing fast zero support. Eric Blake (2): server: Assert sane error responses nozero: More efficient FUA handling filters/nozero/nozero.c | 17 +++++++++++-- server/filters.c | 56 +++++++++++++++++++++++++++++++++-------- server/protocol.c | 32 +++++++++++++++++------ 3 files

..._SERIALIZE_REQUESTS; static int diff --git a/filters/nozero/nozero.c b/filters/nozero/nozero.c index 6e0ffa9..16ec710 100644 --- a/filters/nozero/nozero.c +++ b/filters/nozero/nozero.c @@ -43,8 +43,6 @@ #include "minmax.h" -#define THREAD_MODEL NBDKIT_THREAD_MODEL_PARALLEL - #define MAX_WRITE (64 * 1024 * 1024) static const char buffer[MAX_WRITE]; diff --git a/filters/offset/offset.c b/filters/offset/offset.c index fe07d28..efe5c6d 100644 --- a/filters/offset/offset.c +++ b/filters/offset/offset.c @@ -41,8 +41,6 @@ #include "cleanup.h" -#define THREAD_MODEL NBDKIT_THREAD...

On Wed, Aug 05, 2020 at 03:40:43PM +0300, Nir Soffer wrote: > On Wed, Aug 5, 2020 at 2:58 PM Richard W.M. Jones <rjones@redhat.com> wrote: > > > > On Wed, Aug 05, 2020 at 02:39:44PM +0300, Nir Soffer wrote: > > > Can we use something like the file plugin? thread pool of workers, > > > each keeping open vddk handle, and serving requests in parallel from >

...o PARALLEL ... I'll try it out and get back to you. > I'm not sure what triggers using multiple connections in qemu-img and > how it decide how many connections should be used, but we report > the number of writers in OPTIONS: > http://ovirt.github.io/ovirt-imageio/images.html#max_writers > > There is a hard limit in vdsm, because it runs qemu-nbd with > --shared=8, so you should > not use more than 8 connections, they will just block on qemu-nbd forever. It's different for qemu NBD client and server. Eric told me on IRC a few minutes ago that qemu NBD client d...

...try it out and get back to you. > > > I'm not sure what triggers using multiple connections in qemu-img and > > how it decide how many connections should be used, but we report > > the number of writers in OPTIONS: > > http://ovirt.github.io/ovirt-imageio/images.html#max_writers > > > > There is a hard limit in vdsm, because it runs qemu-nbd with > > --shared=8, so you should > > not use more than 8 connections, they will just block on qemu-nbd forever. > > It's different for qemu NBD client and server. Eric told me on IRC a > few m...

...imageio socket, and this is likely where the plugin spends most of the time. I'm not sure what triggers using multiple connections in qemu-img and how it decide how many connections should be used, but we report the number of writers in OPTIONS: http://ovirt.github.io/ovirt-imageio/images.html#max_writers There is a hard limit in vdsm, because it runs qemu-nbd with --shared=8, so you should not use more than 8 connections, they will just block on qemu-nbd forever. We use 4 connections by default, giving about 100% speed up compared with one connection. 2 connections give about 80% speed up. If...

Being able to programmatically force nbdkit to be less parallel can be useful during testing. I was less sure about patch 3, but if you like it, I'm inclined to instead squash it into patch 1. This patch is written to apply after my NBD_CMD_CACHE work (since I touched the nocache filter); but can be rearranged if we think this series should go in first while that one undergoes any adjustments

...uid = {time_low = 0, time_mid = 0, time_hi_and_version = 0, clock_seq = "\020 ", node = "4(\302\177\000"} protocol = <optimized out> max_limit = <optimized out> max_trans = <optimized out> max_read = <optimized out> max_write = <optimized out> now = 131742515223210910 signing_required = true ok = <optimized out> __FUNCTION__ = "smbd_smb2_request_process_negprot" #21 0x00007fc22836a09c in smbd_smb2_request_dispatch (req=req at entry=0x55b48e61d690) at ../source3/smbd...

v4: https://www.redhat.com/archives/libguestfs/2019-January/msg00032.html v5: - Now we set the block size at run time. I'd like to say that I was able to test this change, but unfortunately I couldn't find any easy way to create a filesystem on x86-64 with a block size > 4K. Ext4 doesn't support it at all, and XFS doesn't support block size > page size (and I

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]

Also available here: https://github.com/rwmjones/nbdkit/tree/2020-windows-mingw-nolib After a lot of work I have made the port to Windows work without using a separate library. Instead, on Windows only, we build an "import library" (library of stubs) which resolves references to nbdkit_* functions in the main program and fixes up the plugin, basically the first technique outlined in