search for: nbdkit_cache_h

...imed.) +Recently used dirty blocks are flushed to the plugin and discarded. + +=back + =head1 ENVIRONMENT VARIABLES =over 4 diff --git a/filters/cache/cache.h b/filters/cache/cache.h index 50416b1..233a4fa 100644 --- a/filters/cache/cache.h +++ b/filters/cache/cache.h @@ -34,6 +34,8 @@ #ifndef NBDKIT_CACHE_H #define NBDKIT_CACHE_H +#include <fcntl.h> + /* Size of a block in the cache. A 4K block size means that we need * 64 MB of memory to store the bitmaps for a 1 TB underlying image. * It is also smaller than the usual hole size for sparse files, which @@ -48,7 +50,18 @@ extern enum ca...

...;cache-low-threshold> you can limit the maximum size of the cache. > + > +This requires kernel and filesystem support (for L<fallocate(2)> > +C<FALLOC_FL_PUNCH_HOLE>), so it may not work on all platforms. > +++ b/filters/cache/cache.h > @@ -34,6 +34,8 @@ > #ifndef NBDKIT_CACHE_H > #define NBDKIT_CACHE_H > > +#include <fcntl.h> > + > /* Size of a block in the cache. A 4K block size means that we need > * 64 MB of memory to store the bitmaps for a 1 TB underlying image. > * It is also smaller than the usual hole size for sparse files, whic...

...tages of C<cache-max-size>. + +Least recently used blocks are discarded first. + =head1 ENVIRONMENT VARIABLES =over 4 diff --git a/filters/cache/cache.h b/filters/cache/cache.h index 50416b1..233a4fa 100644 --- a/filters/cache/cache.h +++ b/filters/cache/cache.h @@ -34,6 +34,8 @@ #ifndef NBDKIT_CACHE_H #define NBDKIT_CACHE_H +#include <fcntl.h> + /* Size of a block in the cache. A 4K block size means that we need * 64 MB of memory to store the bitmaps for a 1 TB underlying image. * It is also smaller than the usual hole size for sparse files, which @@ -48,7 +50,18 @@ extern enum ca...

v3 was broken by a bad rebase, so let's forget about that one. Compared to v2: - Patch 1 is the same except for a minor comment change. - Patch 2 splits the reclaim code into a separate file (filters/cache/reclaim.c) - Addressed Eric's comments from his review of v2. - Retested on Linux and FreeBSD.

Patch 1 is the same as last time, except for a minor comment fix. Patch 2 should address everything that Eric mentioned in his review, and has been retested. Rich.

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

This patch series enhances the cache filter in a few ways, primarily adding a "cache-on-read" feature (similar to qemu's copyonread); and adding the ability to limit the cache size and the antecedent of that which is having a method to reclaim cache blocks. As the cache is stored as a sparse temporary file, reclaiming cache blocks simply means punching holes in the temporary file.

...tages of C<cache-max-size>. + +Least recently used blocks are discarded first. + =head1 ENVIRONMENT VARIABLES =over 4 diff --git a/filters/cache/cache.h b/filters/cache/cache.h index 50416b1..5e0d11b 100644 --- a/filters/cache/cache.h +++ b/filters/cache/cache.h @@ -34,6 +34,8 @@ #ifndef NBDKIT_CACHE_H #define NBDKIT_CACHE_H +#include <fcntl.h> + /* Size of a block in the cache. A 4K block size means that we need * 64 MB of memory to store the bitmaps for a 1 TB underlying image. * It is also smaller than the usual hole size for sparse files, which @@ -48,6 +50,10 @@ extern enum ca...

...ages of C<cache-max-size>. + +Least recently used blocks are discarded first. + =head1 ENVIRONMENT VARIABLES =over 4 diff --git a/filters/cache/cache.h b/filters/cache/cache.h index 50416b1..cafd421 100644 --- a/filters/cache/cache.h +++ b/filters/cache/cache.h @@ -34,12 +34,7 @@ #ifndef NBDKIT_CACHE_H #define NBDKIT_CACHE_H -/* Size of a block in the cache. A 4K block size means that we need - * 64 MB of memory to store the bitmaps for a 1 TB underlying image. - * It is also smaller than the usual hole size for sparse files, which - * means we have no reason to call next_ops->zero. - */ -...

These are essentially identical to what was previously posted as patches 6/9 through 9/9 here: https://www.redhat.com/archives/libguestfs/2018-December/msg00145.html except that it has been rebased onto the current git master and retested thoroughly. Rich.

.../low thresholds. */ +extern int64_t max_size; +extern int hi_thresh, lo_thresh; + /* Cache read requests. */ extern bool cache_on_read; +/* Do we support reclaiming cache blocks? */ +#ifdef FALLOC_FL_PUNCH_HOLE +#define HAVE_CACHE_RECLAIM 1 +#else +#undef HAVE_CACHE_RECLAIM +#endif + #endif /* NBDKIT_CACHE_H */ diff --git a/filters/cache/blk.c b/filters/cache/blk.c index b256446..4a7f65f 100644 --- a/filters/cache/blk.c +++ b/filters/cache/blk.c @@ -46,6 +46,8 @@ #include <unistd.h> #include <fcntl.h> #include <errno.h> +#include <sys/types.h> +#include <sys/stat.h>...