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Block allocation map is now built in a separate thread, and does not delay

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server startup (sparse write avoidance doesn't happen until it is finished).
Added mutex to bitset functions, which were already being called from
multiple threads.  Rewrote allocation map builder to request file
information in multiple chunks, to avoid uninterruptible wait and dynamic
memory allocation.
This commit is contained in:
Matthew Bloch
2012-10-07 21:55:01 +01:00
parent 7b13964c39
commit a49cf14927
6 changed files with 112 additions and 81 deletions
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100
src/ioutil.c
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@@ -11,83 +11,51 @@
#include "util.h"
#include "bitset.h"
struct bitset_mapping* build_allocation_map(int fd, uint64_t size, int resolution)
int build_allocation_map(struct bitset_mapping* allocation_map, int fd)
{
unsigned int i;
struct bitset_mapping* allocation_map = bitset_alloc(size, resolution);
struct fiemap *fiemap_count = NULL, *fiemap = NULL;
/* break blocking ioctls down */
const unsigned long max_length = 100*1024*1024;
const unsigned int max_extents = 1000;
fiemap_count = (struct fiemap*) xmalloc(sizeof(struct fiemap));
unsigned long offset = 0;
fiemap_count->fm_start = 0;
fiemap_count->fm_length = size;
fiemap_count->fm_flags = FIEMAP_FLAG_SYNC;
fiemap_count->fm_extent_count = 0;
fiemap_count->fm_mapped_extents = 0;
struct {
struct fiemap fiemap;
struct fiemap_extent extents[max_extents];
} fiemap_static;
struct fiemap* fiemap = (struct fiemap*) &fiemap_static;
/* Find out how many extents there are */
if (ioctl(fd, FS_IOC_FIEMAP, fiemap_count) < 0) {
debug( "Couldn't get fiemap_count, returning no allocation_map" );
goto no_map;
}
memset(&fiemap_static, 0, sizeof(fiemap_static));
/* Resize fiemap to allow us to read in the extents */
fiemap = (struct fiemap*)xmalloc(
sizeof(struct fiemap) + (
sizeof(struct fiemap_extent) *
fiemap_count->fm_mapped_extents
)
for (offset = 0; offset < allocation_map->size; offset += fiemap->fm_length) {
unsigned int i;
fiemap->fm_start = offset;
fiemap->fm_length = max_length;
if (offset + max_length > allocation_map->size)
fiemap->fm_length = allocation_map->size-offset;
fiemap->fm_flags = FIEMAP_FLAG_SYNC;
fiemap->fm_extent_count = max_extents;
fiemap->fm_mapped_extents = 0;
if (ioctl(fd, FS_IOC_FIEMAP, fiemap) < 0) {
debug( "Couldn't get fiemap, returning no allocation_map" );
free(allocation_map);
return NULL;
}
for (i=0;i<fiemap->fm_mapped_extents;i++) {
bitset_set_range(
allocation_map,
fiemap->fm_extents[i].fe_logical,
fiemap->fm_extents[i].fe_length
);
/* realloc makes valgrind complain a lot */
memcpy(fiemap, fiemap_count, sizeof(struct fiemap));
free( fiemap_count );
fiemap->fm_extent_count = fiemap->fm_mapped_extents;
fiemap->fm_mapped_extents = 0;
if (ioctl(fd, FS_IOC_FIEMAP, fiemap) < 0) {
debug( "Couldn't get fiemap, returning no allocation_map" );
goto no_map;
}
for (i=0;i<fiemap->fm_mapped_extents;i++) {
bitset_set_range(
allocation_map,
fiemap->fm_extents[i].fe_logical,
fiemap->fm_extents[i].fe_length
);
}
/* This is pointlessly verbose for real discs, it's here as a
* reference for pulling data out of the allocation map */
if ( 0 ) {
for (i=0; i<(size/resolution); i++) {
debug("map[%d] = %d%d%d%d%d%d%d%d",
i,
(allocation_map->bits[i] & 1) == 1,
(allocation_map->bits[i] & 2) == 2,
(allocation_map->bits[i] & 4) == 4,
(allocation_map->bits[i] & 8) == 8,
(allocation_map->bits[i] & 16) == 16,
(allocation_map->bits[i] & 32) == 32,
(allocation_map->bits[i] & 64) == 64,
(allocation_map->bits[i] & 128) == 128
);
//debug("range from %ld + %ld", fiemap->fm_extents[i].fe_logical, fiemap->fm_extents[i].fe_length);
}
}
free(fiemap);
debug("Successfully built allocation map");
return allocation_map;
no_map:
free( allocation_map );
if ( NULL != fiemap ) { free( fiemap ); }
if ( NULL != fiemap_count ) { free( fiemap_count ); }
return NULL;
}