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super1: make internal bitmap size calculations more consistent 

Determining internal bitmap size is performed using two different
functions (bitmap_sectors() and calc_bitmap_size()) and in
getinfo_super1() it is calculated in yet another way. Each of these
methods give slightly different results. The most accurate is
calc_bitmap_size() but it also has a rounding issue. So:

- fix the rounding issue in calc_bitmap_size() using bitmap_bits()
- replace usages of bitmap_sectors() and open-coded calculations with
  calc_bitmap_size()
- remove bitmap_sectors()
- move bitmap_bits() to mdadm.h as inline - otherwise mdassemble won't
  compile (it does not use bitmap.c)

Signed-off-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
This commit is contained in:
Artur Paszkiewicz 2016-11-10 11:50:53 +01:00 committed by Jes Sorensen
parent 52a9408561
commit 561ad5597b
3 changed files with 17 additions and 32 deletions
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15
bitmap.c
View File

@ -108,21 +108,6 @@ static int count_dirty_bits(char *buf, int num_bits)
return num;
}
/* calculate the size of the bitmap given the array size and bitmap chunksize */
static unsigned long long
bitmap_bits(unsigned long long array_size, unsigned long chunksize)
{
return (array_size * 512 + chunksize - 1) / chunksize;
}
unsigned long bitmap_sectors(struct bitmap_super_s *bsb)
{
unsigned long long bits = bitmap_bits(__le64_to_cpu(bsb->sync_size),
__le32_to_cpu(bsb->chunksize));
int bits_per_sector = 8*512;
return (bits + bits_per_sector - 1) / bits_per_sector;
}
static bitmap_info_t *bitmap_fd_read(int fd, int brief)
{
/* Note: fd might be open O_DIRECT, so we must be

9
mdadm.h
View File

@ -1331,7 +1331,14 @@ extern int CreateBitmap(char *filename, int force, char uuid[16],
extern int ExamineBitmap(char *filename, int brief, struct supertype *st);
extern int Write_rules(char *rule_name);
extern int bitmap_update_uuid(int fd, int *uuid, int swap);
extern unsigned long bitmap_sectors(struct bitmap_super_s *bsb);
/* calculate the size of the bitmap given the array size and bitmap chunksize */
static inline unsigned long long
bitmap_bits(unsigned long long array_size, unsigned long chunksize)
{
return (array_size * 512 + chunksize - 1) / chunksize;
}
extern int Dump_metadata(char *dev, char *dir, struct context *c,
struct supertype *st);
extern int Restore_metadata(char *dev, char *dir, struct context *c,

25
super1.c
View File

@ -162,7 +162,8 @@ static unsigned int calc_bitmap_size(bitmap_super_t *bms, unsigned int boundary)
{
unsigned long long bits, bytes;
bits = __le64_to_cpu(bms->sync_size) / (__le32_to_cpu(bms->chunksize)>>9);
bits = bitmap_bits(__le64_to_cpu(bms->sync_size),
__le32_to_cpu(bms->chunksize));
bytes = (bits+7) >> 3;
bytes += sizeof(bitmap_super_t);
bytes = ROUND_UP(bytes, boundary);
@ -973,11 +974,7 @@ static void getinfo_super1(struct supertype *st, struct mdinfo *info, char *map)
earliest = super_offset + (32+4)*2; /* match kernel */
if (info->bitmap_offset > 0) {
unsigned long long bmend = info->bitmap_offset;
unsigned long long size = __le64_to_cpu(bsb->sync_size);
size /= __le32_to_cpu(bsb->chunksize) >> 9;
size = (size + 7) >> 3;
size += sizeof(bitmap_super_t);
size = ROUND_UP(size, 4096);
unsigned long long size = calc_bitmap_size(bsb, 4096);
size /= 512;
bmend += size;
if (bmend > earliest)
@ -1219,11 +1216,8 @@ static int update_super1(struct supertype *st, struct mdinfo *info,
} else if (strcmp(update, "uuid") == 0) {
copy_uuid(sb->set_uuid, info->uuid, super1.swapuuid);
if (__le32_to_cpu(sb->feature_map)&MD_FEATURE_BITMAP_OFFSET) {
struct bitmap_super_s *bm;
bm = (struct bitmap_super_s*)(st->sb+MAX_SB_SIZE);
memcpy(bm->uuid, sb->set_uuid, 16);
}
if (__le32_to_cpu(sb->feature_map) & MD_FEATURE_BITMAP_OFFSET)
memcpy(bms->uuid, sb->set_uuid, 16);
} else if (strcmp(update, "no-bitmap") == 0) {
sb->feature_map &= ~__cpu_to_le32(MD_FEATURE_BITMAP_OFFSET);
} else if (strcmp(update, "bbl") == 0) {
@ -1232,15 +1226,14 @@ static int update_super1(struct supertype *st, struct mdinfo *info,
*/
unsigned long long sb_offset = __le64_to_cpu(sb->super_offset);
unsigned long long data_offset = __le64_to_cpu(sb->data_offset);
long bitmap_offset = (long)(int32_t)__le32_to_cpu(sb->bitmap_offset);
long bitmap_offset = 0;
long bm_sectors = 0;
long space;
#ifndef MDASSEMBLE
if (sb->feature_map & __cpu_to_le32(MD_FEATURE_BITMAP_OFFSET)) {
struct bitmap_super_s *bsb;
bsb = (struct bitmap_super_s *)(((char*)sb)+MAX_SB_SIZE);
bm_sectors = bitmap_sectors(bsb);
bitmap_offset = (long)__le32_to_cpu(sb->bitmap_offset);
bm_sectors = calc_bitmap_size(bms, 4096) >> 9;
}
#endif
if (sb_offset < data_offset) {
@ -2120,7 +2113,7 @@ static __u64 avail_size1(struct supertype *st, __u64 devsize,
/* hot-add. allow for actual size of bitmap */
struct bitmap_super_s *bsb;
bsb = (struct bitmap_super_s *)(((char*)super)+MAX_SB_SIZE);
bmspace = bitmap_sectors(bsb);
bmspace = calc_bitmap_size(bsb, 4096) >> 9;
}
#endif
/* Allow space for bad block log */