similar to: [PATCH] daemon: Move the useful 'is_zero' function into common code.

v1 -> v2: The first patch is the same (the pure refactoring), but in the second patch I implement Eric Blake's suggested version. Rich.

On Wed, Apr 19, 2017 at 09:35:16AM -0500, Eric Blake wrote: > On 04/19/2017 09:17 AM, Richard W.M. Jones wrote: > > This is largely a simple refactoring, but it combines another > > definition of this function from virt-builder which had a slightly > > different prototype. > > --- > > > +/* Return true iff the buffer is all zero bytes. > > + * > > +

On 04/19/2017 09:17 AM, Richard W.M. Jones wrote: > This is largely a simple refactoring, but it combines another > definition of this function from virt-builder which had a slightly > different prototype. > --- > +/* Return true iff the buffer is all zero bytes. > + * > + * Note that gcc is smart enough to optimize this properly: > + *

On Wednesday, 19 April 2017 18:46:37 CEST Richard W.M. Jones wrote: > v1 -> v2: > > The first patch is the same (the pure refactoring), but in the second > patch I implement Eric Blake's suggested version. LGTM -- can you please add Eric's text to the comment of is_zero, so it is easier to remember why the 16-bytes trick is done? Thanks, -- Pino Toscano

Fast testing whether the AIO buffer (or regions within it) contain all zeroes, which allows Python code to quickly do sparsification when copying. This includes the iszero.h header from nbdkit which is distributed under a compatible license. --- common/include/Makefile.am | 5 +-- common/include/iszero.h | 63 +++++++++++++++++++++++++++++++++++++ generator/generator | 17

When sparse_array_zero() is used for a range larger than a page, there's no need to waste time in memset() or is_zero() - we already know the page will be free()d. Signed-off-by: Eric Blake <eblake@redhat.com> --- Here's a fun one :) common/sparse/sparse.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/common/sparse/sparse.c b/common/sparse/sparse.c

On 2/17/20 9:13 AM, Max Reitz wrote: > Hi, > > It’s my understanding that without some is_zero infrastructure for QEMU, > it’s impossible to implement this flag in qemu’s NBD server. You're right that we may need some more infrastructure before being able to decide when to report this bit in all cases. But for raw files, that infrastructure already exists: does block_status at

Updating gnulib has caused -Wformat-signedness to be enabled. This has revealed many problems in C format strings. The fixes here fall into the following main categories: - Using %d with an unsigned parameter. - %x and %o expect an unsigned argument. - uid_t and gid_t are unsigned on Linux. The safe way to print these is to cast them to uintmax_t and then print then using the %ju

Updating gnulib has caused -Wformat-signedness to be enabled. This has revealed many problems in C format strings. The fixes here fall into the following main categories: - Using %d with an unsigned parameter. - %x and %o expect an unsigned argument. - uid_t and gid_t are unsigned on Linux. The safe way to print these is to cast them to uintmax_t and then print them using the %ju

On 1/30/20 8:05 AM, Richard W.M. Jones wrote: > Fast testing whether the AIO buffer (or regions within it) contain all > zeroes, which allows Python code to quickly do sparsification when > copying. > > This includes the iszero.h header from nbdkit which is distributed > under a compatible license. > --- > common/include/Makefile.am | 5 +-- >

On Thu, Jan 30, 2020 at 02:29:21PM +0000, Richard W.M. Jones wrote: >On Thu, Jan 30, 2020 at 08:16:30AM -0600, Eric Blake wrote: >> On 1/30/20 8:05 AM, Richard W.M. Jones wrote: >> >Fast testing whether the AIO buffer (or regions within it) contain all >> >zeroes, which allows Python code to quickly do sparsification when >> >copying. >> > >>

--- pxzcat.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/pxzcat.c b/pxzcat.c index 9bcdc36..55ccfc0 100644 --- a/pxzcat.c +++ b/pxzcat.c @@ -44,10 +44,11 @@ #include <sys/types.h> #include <error.h> #include <errno.h> #include <getopt.h> #include <pthread.h> +#include <linux/falloc.h> #include <lzma.h> #define DEBUG

On Thu, Jan 30, 2020 at 04:16:09PM +0100, Martin Kletzander wrote: > I know this probably got answered somewhere, but I've never gotten > any when asking myself. So let me use this opportunity. > > Because I really despise useless processes and duplicated > information I always hated the way all the "mandatory" file headers. > As far as I understand it's

On 10/22/2013 05:56 PM, Gabriel de Perthuis wrote: > --- > pxzcat.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/pxzcat.c b/pxzcat.c > index 4ab8689..9bcdc36 100644 > --- a/pxzcat.c > +++ b/pxzcat.c > @@ -29,10 +29,11 @@ > * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT > * OF THE USE OF THIS SOFTWARE,

--- builder/pxzcat-c.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/builder/pxzcat-c.c b/builder/pxzcat-c.c index 0bbd296..dec9cc2 100644 --- a/builder/pxzcat-c.c +++ b/builder/pxzcat-c.c @@ -214,8 +214,10 @@ pxzcat (value filenamev, value outputfilev, unsigned nr_threads) unix_error (err, (char *) "ftruncate", outputfilev); } +#if defined HAVE_POSIX_FADVISE /*

--- pxzcat.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/pxzcat.c b/pxzcat.c index 4ab8689..9bcdc36 100644 --- a/pxzcat.c +++ b/pxzcat.c @@ -29,10 +29,11 @@ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ +#define _GNU_SOURCE #include <config.h>

--- builder/builder.ml | 84 +++++++++++++++++++++++++++++++++---------- common/mlutils/unix_utils-c.c | 27 ++++++++++++++ common/mlutils/unix_utils.ml | 3 ++ common/mlutils/unix_utils.mli | 4 +++ m4/guestfs_libraries.m4 | 1 + 5 files changed, 100 insertions(+), 19 deletions(-) diff --git a/builder/builder.ml b/builder/builder.ml index d8e625f68..fd19aa7d9 100644 ---

Add wrappers around posix_fadvise and use them in places we were calling posix_fadvise directly before. Also in virt-builder we were doing this (and ignoring the result): posix_fadvise (fd, 0, 0, POSIX_FADV_RANDOM|POSIX_FADV_DONTNEED); However the POSIX_FADV_* flags are _not_ bitmasks! In fact POSIX_FADV_RANDOM|POSIX_FADV_DONTNEED == POSIX_FADV_NOREUSE so we were giving a completely

On 08/01/2018 06:10 AM, Richard W.M. Jones wrote: > This can truncate, extend, or round up/down to a multiple. > --- > common-rules.mk | 3 +- > configure.ac | 1 + > filters/offset/nbdkit-offset-filter.pod | 7 +- > filters/partition/nbdkit-partition-filter.pod | 1 + >

Just call close on the specified fd, if valid. --- daemon/daemon.h | 3 +++ daemon/guestfsd.c | 9 +++++++++ 2 files changed, 12 insertions(+) diff --git a/daemon/daemon.h b/daemon/daemon.h index fb74e91..0caad45 100644 --- a/daemon/daemon.h +++ b/daemon/daemon.h @@ -173,6 +173,7 @@ asprintf_nowarn (char **strp, const char *fmt, ...) extern void cleanup_free (void *ptr); extern void