diff options
Diffstat (limited to 'fs/ubifs/budget.c')
-rw-r--r-- | fs/ubifs/budget.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c index 101d278c591d..73db464cd08b 100644 --- a/fs/ubifs/budget.c +++ b/fs/ubifs/budget.c | |||
@@ -723,24 +723,25 @@ void ubifs_release_dirty_inode_budget(struct ubifs_info *c, | |||
723 | */ | 723 | */ |
724 | long long ubifs_reported_space(const struct ubifs_info *c, uint64_t free) | 724 | long long ubifs_reported_space(const struct ubifs_info *c, uint64_t free) |
725 | { | 725 | { |
726 | int divisor, factor; | 726 | int divisor, factor, f; |
727 | 727 | ||
728 | /* | 728 | /* |
729 | * Reported space size is @free * X, where X is UBIFS block size | 729 | * Reported space size is @free * X, where X is UBIFS block size |
730 | * divided by UBIFS block size + all overhead one data block | 730 | * divided by UBIFS block size + all overhead one data block |
731 | * introduces. The overhead is the node header + indexing overhead. | 731 | * introduces. The overhead is the node header + indexing overhead. |
732 | * | 732 | * |
733 | * Indexing overhead is calculations are based on the following | 733 | * Indexing overhead calculations are based on the following formula: |
734 | * formula: I = N/(f - 1) + 1, where I - number of indexing nodes, N - | 734 | * I = N/(f - 1) + 1, where I - number of indexing nodes, N - number |
735 | * number of data nodes, f - fanout. Because effective UBIFS fanout is | 735 | * of data nodes, f - fanout. Because effective UBIFS fanout is twice |
736 | * twice as less than maximum fanout, we assume that each data node | 736 | * as less than maximum fanout, we assume that each data node |
737 | * introduces 3 * @c->max_idx_node_sz / (@c->fanout/2 - 1) bytes. | 737 | * introduces 3 * @c->max_idx_node_sz / (@c->fanout/2 - 1) bytes. |
738 | * Note, the multiplier 3 is because UBIFS reseves thrice as more space | 738 | * Note, the multiplier 3 is because UBIFS reseves thrice as more space |
739 | * for the index. | 739 | * for the index. |
740 | */ | 740 | */ |
741 | f = c->fanout > 3 ? c->fanout >> 1 : 2; | ||
741 | factor = UBIFS_BLOCK_SIZE; | 742 | factor = UBIFS_BLOCK_SIZE; |
742 | divisor = UBIFS_MAX_DATA_NODE_SZ; | 743 | divisor = UBIFS_MAX_DATA_NODE_SZ; |
743 | divisor += (c->max_idx_node_sz * 3) / ((c->fanout >> 1) - 1); | 744 | divisor += (c->max_idx_node_sz * 3) / (f - 1); |
744 | free *= factor; | 745 | free *= factor; |
745 | do_div(free, divisor); | 746 | do_div(free, divisor); |
746 | return free; | 747 | return free; |