UBIFS: fix available blocks count

Take into account that 2 eraseblocks are never available because
they are reserved for the index. This gives more realistic count
of FS blocks.

To avoid future confusions like this, introduce a constant.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
This commit is contained in:
Artem Bityutskiy 2008-12-19 19:26:29 +02:00
parent d3cf502b6c
commit af14a1ad79
3 changed files with 13 additions and 9 deletions

View file

@ -280,13 +280,8 @@ int ubifs_calc_min_idx_lebs(struct ubifs_info *c)
* extra LEB to compensate.
*/
ret += 1;
/*
* At present the index needs at least 2 LEBs: one for the index head
* and one for in-the-gaps method (which currently does not cater for
* the index head and so excludes it from consideration).
*/
if (ret < 2)
ret = 2;
if (ret < MIN_INDEX_LEBS)
ret = MIN_INDEX_LEBS;
return ret;
}

View file

@ -695,9 +695,10 @@ static int init_constants_late(struct ubifs_info *c)
* necessary to report something for the 'statfs()' call.
*
* Subtract the LEB reserved for GC, the LEB which is reserved for
* deletions, and assume only one journal head is available.
* deletions, minimum LEBs for the index, and assume only one journal
* head is available.
*/
tmp64 = c->main_lebs - 2 - c->jhead_cnt + 1;
tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
tmp64 *= (uint64_t)c->leb_size - c->leb_overhead;
tmp64 = ubifs_reported_space(c, tmp64);
c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;

View file

@ -63,6 +63,14 @@
#define SQNUM_WARN_WATERMARK 0xFFFFFFFF00000000ULL
#define SQNUM_WATERMARK 0xFFFFFFFFFF000000ULL
/*
* Minimum amount of LEBs reserved for the index. At present the index needs at
* least 2 LEBs: one for the index head and one for in-the-gaps method (which
* currently does not cater for the index head and so excludes it from
* consideration).
*/
#define MIN_INDEX_LEBS 2
/* Minimum amount of data UBIFS writes to the flash */
#define MIN_WRITE_SZ (UBIFS_DATA_NODE_SZ + 8)