UBIFS: introduce a helpful variable
This patch introduces a helpful @c->idx_leb_size variable.
The patch also fixes some spelling issues and makes comments
use "LEB" instead of "eraseblock", which is more correct.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c
index f393620..8cd425b 100644
--- a/fs/ubifs/budget.c
+++ b/fs/ubifs/budget.c
@@ -194,29 +194,26 @@
}
/**
- * ubifs_calc_min_idx_lebs - calculate amount of eraseblocks for the index.
+ * ubifs_calc_min_idx_lebs - calculate amount of LEBs for the index.
* @c: UBIFS file-system description object
*
- * This function calculates and returns the number of eraseblocks which should
- * be kept for index usage.
+ * This function calculates and returns the number of LEBs which should be kept
+ * for index usage.
*/
int ubifs_calc_min_idx_lebs(struct ubifs_info *c)
{
- int idx_lebs, eff_leb_size = c->leb_size - c->max_idx_node_sz;
+ int idx_lebs;
long long idx_size;
idx_size = c->old_idx_sz + c->budg_idx_growth + c->budg_uncommitted_idx;
-
/* And make sure we have thrice the index size of space reserved */
- idx_size = idx_size + (idx_size << 1);
-
+ idx_size += idx_size << 1;
/*
* We do not maintain 'old_idx_size' as 'old_idx_lebs'/'old_idx_bytes'
* pair, nor similarly the two variables for the new index size, so we
* have to do this costly 64-bit division on fast-path.
*/
- idx_size += eff_leb_size - 1;
- idx_lebs = div_u64(idx_size, eff_leb_size);
+ idx_lebs = div_u64(idx_size + c->idx_leb_size - 1, c->idx_leb_size);
/*
* The index head is not available for the in-the-gaps method, so add an
* extra LEB to compensate.
@@ -310,15 +307,15 @@
* do_budget_space - reserve flash space for index and data growth.
* @c: UBIFS file-system description object
*
- * This function makes sure UBIFS has enough free eraseblocks for index growth
- * and data.
+ * This function makes sure UBIFS has enough free LEBs for index growth and
+ * data.
*
* When budgeting index space, UBIFS reserves thrice as many 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 3,
- * and makes sure this does not exceed the amount of free eraseblocks.
+ * and makes sure this does not exceed the amount of free LEBs.
*
* Notes about @c->min_idx_lebs and @c->lst.idx_lebs variables:
* o @c->lst.idx_lebs is the number of LEBs the index currently uses. It might
@@ -695,12 +692,12 @@
* This function calculates amount of free space to report to user-space.
*
* Because UBIFS may introduce substantial overhead (the index, node headers,
- * alignment, wastage at the end of eraseblocks, etc), it cannot report real
- * amount of free flash space it has (well, because not all dirty space is
- * reclaimable, UBIFS does not actually know the real amount). If UBIFS did so,
- * it would bread user expectations about what free space is. Users seem to
- * accustomed to assume that if the file-system reports N bytes of free space,
- * they would be able to fit a file of N bytes to the FS. This almost works for
+ * alignment, wastage at the end of LEBs, etc), it cannot report real amount of
+ * free flash space it has (well, because not all dirty space is reclaimable,
+ * UBIFS does not actually know the real amount). If UBIFS did so, it would
+ * bread user expectations about what free space is. Users seem to accustomed
+ * to assume that if the file-system reports N bytes of free space, they would
+ * be able to fit a file of N bytes to the FS. This almost works for
* traditional file-systems, because they have way less overhead than UBIFS.
* So, to keep users happy, UBIFS tries to take the overhead into account.
*/
diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
index e070c64..0dec47c 100644
--- a/fs/ubifs/sb.c
+++ b/fs/ubifs/sb.c
@@ -623,7 +623,6 @@
c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
c->main_first = c->leb_cnt - c->main_lebs;
- c->report_rp_size = ubifs_reported_space(c, c->rp_size);
err = validate_sb(c, sup);
out:
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 03cd9ac4..7bdd248 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -700,6 +700,8 @@
if (err)
return err;
+ /* Initialize effective LEB size used in budgeting calculations */
+ c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
return 0;
}
@@ -716,6 +718,7 @@
long long tmp64;
c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
+ c->report_rp_size = ubifs_reported_space(c, c->rp_size);
/*
* Calculate total amount of FS blocks. This number is not used
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 2da1193..a53b9a6 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -1015,6 +1015,8 @@
* @min_io_shift: number of bits in @min_io_size minus one
* @leb_size: logical eraseblock size in bytes
* @half_leb_size: half LEB size
+ * @idx_leb_size: how many bytes of an LEB are effectively available when it is
+ * used to store indexing nodes (@leb_size - @max_idx_node_sz)
* @leb_cnt: count of logical eraseblocks
* @max_leb_cnt: maximum count of logical eraseblocks
* @old_leb_cnt: count of logical eraseblocks before re-size
@@ -1132,8 +1134,8 @@
* previous commit start
* @uncat_list: list of un-categorized LEBs
* @empty_list: list of empty LEBs
- * @freeable_list: list of freeable non-index LEBs (free + dirty == leb_size)
- * @frdi_idx_list: list of freeable index LEBs (free + dirty == leb_size)
+ * @freeable_list: list of freeable non-index LEBs (free + dirty == @leb_size)
+ * @frdi_idx_list: list of freeable index LEBs (free + dirty == @leb_size)
* @freeable_cnt: number of freeable LEBs in @freeable_list
*
* @ltab_lnum: LEB number of LPT's own lprops table
@@ -1253,6 +1255,7 @@
int min_io_shift;
int leb_size;
int half_leb_size;
+ int idx_leb_size;
int leb_cnt;
int max_leb_cnt;
int old_leb_cnt;
