From fb1cd01a33ecb8a49d590c034ba146dff80c5597 Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Mon, 16 Mar 2009 09:56:57 +0200 Subject: 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 --- fs/ubifs/budget.c | 33 +++++++++++++++------------------ fs/ubifs/sb.c | 1 - fs/ubifs/super.c | 3 +++ fs/ubifs/ubifs.h | 7 +++++-- 4 files changed, 23 insertions(+), 21 deletions(-) diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c index f393620890ee..8cd425b628ee 100644 --- a/fs/ubifs/budget.c +++ b/fs/ubifs/budget.c @@ -194,29 +194,26 @@ static int make_free_space(struct ubifs_info *c) } /** - * 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 @@ static int can_use_rp(struct ubifs_info *c) * 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 @@ long long ubifs_reported_space(const struct ubifs_info *c, long long free) * 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 e070c643d1bb..0dec47c87c6d 100644 --- a/fs/ubifs/sb.c +++ b/fs/ubifs/sb.c @@ -623,7 +623,6 @@ int ubifs_read_superblock(struct ubifs_info *c) 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 03cd9ac4dcb2..7bdd248ec770 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -700,6 +700,8 @@ static int init_constants_sb(struct ubifs_info *c) 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 @@ static void init_constants_master(struct ubifs_info *c) 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 2da1193a381f..a53b9a6df2be 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -1015,6 +1015,8 @@ struct ubifs_debug_info; * @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 @@ struct ubifs_debug_info; * 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 @@ struct ubifs_info { 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; -- cgit v1.2.3