From: Mikulas Patocka Date: Wed, 19 Jul 2017 15:23:40 +0000 (-0400) Subject: dm integrity: fix inefficient allocation of journal space X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=9dd59727dbc21d33a9add4c5b308a5775cd5a6ef;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git dm integrity: fix inefficient allocation of journal space When using a block size greater than 512 bytes, the dm-integrity target allocates journal space inefficiently. It allocates one journal entry for each 512-byte chunk of data, fills an entry for each block of data and leaves the remaining entries unused. This issue doesn't cause data corruption, but all the unused journal entries degrade performance severely. For example, with 4k blocks and an 8k bio, it would allocate 16 journal entries but only use 2 entries. The remaining 14 entries were left unused. Fix this by adding the missing 'log2_sectors_per_block' shifts that are required to have each journal entry map to a full block. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Fixes: 7eada909bfd7 ("dm: add integrity target") Signed-off-by: Mike Snitzer --- diff --git a/drivers/md/dm-integrity.c b/drivers/md/dm-integrity.c index 1b224aa9cf15..4b2fd524e38d 100644 --- a/drivers/md/dm-integrity.c +++ b/drivers/md/dm-integrity.c @@ -1587,16 +1587,18 @@ retry: if (likely(ic->mode == 'J')) { if (dio->write) { unsigned next_entry, i, pos; - unsigned ws, we; + unsigned ws, we, range_sectors; - dio->range.n_sectors = min(dio->range.n_sectors, ic->free_sectors); + dio->range.n_sectors = min(dio->range.n_sectors, + ic->free_sectors << ic->sb->log2_sectors_per_block); if (unlikely(!dio->range.n_sectors)) goto sleep; - ic->free_sectors -= dio->range.n_sectors; + range_sectors = dio->range.n_sectors >> ic->sb->log2_sectors_per_block; + ic->free_sectors -= range_sectors; journal_section = ic->free_section; journal_entry = ic->free_section_entry; - next_entry = ic->free_section_entry + dio->range.n_sectors; + next_entry = ic->free_section_entry + range_sectors; ic->free_section_entry = next_entry % ic->journal_section_entries; ic->free_section += next_entry / ic->journal_section_entries; ic->n_uncommitted_sections += next_entry / ic->journal_section_entries;