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>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 2dbaa4fc2cbb..a6a7798d020b 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -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;