UBIFS: reserve more space for index

At the moment UBIFS reserves twice old index size space for the
index. But this is not enough in some cases, because if the indexing
node are very fragmented and there are many small gaps, while the
dirty index has big znodes - in-the-gaps method would fail.

Thus, reserve trise as more, in which case we are guaranteed that
we can commit in any case.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c
index a3978ba4215e1366eb1bfbdb4d65d0d3e5e75998..323d83a4d099fe0a9b9eb6a0c899d3355a113da8 100644 (file)
--- a/fs/ubifs/budget.c
+++ b/fs/ubifs/budget.c
@@ -263,8 +263,8 @@ int ubifs_calc_min_idx_lebs(struct ubifs_info *c)
 
        idx_size = c->old_idx_sz + c->budg_idx_growth + c->budg_uncommitted_idx;
 
-       /* And make sure we have twice the index size of space reserved */
-       idx_size <<= 1;
+       /* And make sure we have trice the index size of space reserved */
+       idx_size = idx_size + (idx_size << 1);
 
        /*
         * We do not maintain 'old_idx_size' as 'old_idx_lebs'/'old_idx_bytes'
@@ -388,11 +388,11 @@ static int can_use_rp(struct ubifs_info *c)
  * This function makes sure UBIFS has enough free eraseblocks for index growth
  * and data.
  *
- * When budgeting index space, UBIFS reserves twice as more LEBs as the index
+ * When budgeting index space, UBIFS reserves trice as more LEBs as the index
  * would take if it was consolidated and written to the flash. This guarantees
  * that the "in-the-gaps" commit method always succeeds and UBIFS will always
  * be able to commit dirty index. So this function basically adds amount of
- * budgeted index space to the size of the current index, multiplies this by 2,
+ * budgeted index space to the size of the current index, multiplies this by 3,
  * and makes sure this does not exceed the amount of free eraseblocks.
  *
  * Notes about @c->min_idx_lebs and @c->lst.idx_lebs variables:

diff --git a/fs/ubifs/find.c b/fs/ubifs/find.c
index 10394c548367320ff463e6f3e8c5a034eab77811..c70c7679c1bf2441d644aa042cc0f3ee6d483f4e 100644 (file)
--- a/fs/ubifs/find.c
+++ b/fs/ubifs/find.c
@@ -290,9 +290,14 @@ int ubifs_find_dirty_leb(struct ubifs_info *c, struct ubifs_lprops *ret_lp,
                idx_lp = idx_heap->arr[0];
                sum = idx_lp->free + idx_lp->dirty;
                /*
-                * Since we reserve twice as more space for the index than it
+                * Since we reserve trice as more space for the index than it
                 * actually takes, it does not make sense to pick indexing LEBs
-                * with less than half LEB of dirty space.
+                * with less than, say, half LEB of dirty space. May be half is
+                * not the optimal boundary - this should be tested and
+                * checked. This boundary should determine how much we use
+                * in-the-gaps to consolidate the index comparing to how much
+                * we use garbage collector to consolidate it. The "half"
+                * criteria just feels to be fine.
                 */
                if (sum < min_space || sum < c->half_leb_size)
                        idx_lp = NULL;

diff --git a/fs/ubifs/misc.h b/fs/ubifs/misc.h
index cd83ffc8101caf6e98b5b45cbbb173aed61fb8f2..87dabf9fe742ea05674ec8cb2bf78f5fe98f510d 100644 (file)
--- a/fs/ubifs/misc.h
+++ b/fs/ubifs/misc.h
@@ -308,7 +308,7 @@ static inline long long ubifs_reported_space(const struct ubifs_info *c,
 {
        int divisor, factor;
 
-       divisor = UBIFS_MAX_DATA_NODE_SZ + (c->max_idx_node_sz << 1);
+       divisor = UBIFS_MAX_DATA_NODE_SZ + (c->max_idx_node_sz * 3);
        factor = UBIFS_MAX_DATA_NODE_SZ - UBIFS_DATA_NODE_SZ;
        do_div(free, divisor);
 

diff --git a/fs/ubifs/ubifs-media.h b/fs/ubifs/ubifs-media.h
index 0cc7da9bed472b778f543229dcb1a8540105b920..bd2121f3426eb5cacee42602dca1dcacb0150acd 100644 (file)
--- a/fs/ubifs/ubifs-media.h
+++ b/fs/ubifs/ubifs-media.h
@@ -228,10 +228,10 @@ enum {
 /* Minimum number of orphan area logical eraseblocks */
 #define UBIFS_MIN_ORPH_LEBS 1
 /*
- * Minimum number of main area logical eraseblocks (buds, 2 for the index, 1
+ * Minimum number of main area logical eraseblocks (buds, 3 for the index, 1
  * for GC, 1 for deletions, and at least 1 for committed data).
  */
-#define UBIFS_MIN_MAIN_LEBS (UBIFS_MIN_BUD_LEBS + 5)
+#define UBIFS_MIN_MAIN_LEBS (UBIFS_MIN_BUD_LEBS + 6)
 
 /* Minimum number of logical eraseblocks */
 #define UBIFS_MIN_LEB_CNT (UBIFS_SB_LEBS + UBIFS_MST_LEBS + \