diff options
| -rw-r--r-- | Documentation/admin-guide/device-mapper/writecache.rst | 3 | ||||
| -rw-r--r-- | drivers/md/dm-writecache.c | 16 |
2 files changed, 15 insertions, 4 deletions
diff --git a/Documentation/admin-guide/device-mapper/writecache.rst b/Documentation/admin-guide/device-mapper/writecache.rst index c181f26af769..977f82b5a811 100644 --- a/Documentation/admin-guide/device-mapper/writecache.rst +++ b/Documentation/admin-guide/device-mapper/writecache.rst @@ -68,6 +68,9 @@ Constructor parameters: specifies the maximum age of a block in milliseconds. If a block is stored in the cache for too long, it will be written to the underlying device and cleaned up. + metadata_only + only metadata is promoted to the cache. This option + improves performance for heavier REQ_META workloads. Status: 1. error indicator - 0 if there was no error, otherwise error number diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c index 558d39764e6d..2eb7d7bcdfb1 100644 --- a/drivers/md/dm-writecache.c +++ b/drivers/md/dm-writecache.c @@ -171,6 +171,7 @@ struct dm_writecache { bool flush_on_suspend:1; bool cleaner:1; bool cleaner_set:1; + bool metadata_only:1; unsigned high_wm_percent_value; unsigned low_wm_percent_value; @@ -1301,7 +1302,7 @@ static int writecache_map(struct dm_target *ti, struct bio *bio) writecache_flush(wc); if (writecache_has_error(wc)) goto unlock_error; - if (unlikely(wc->cleaner)) + if (unlikely(wc->cleaner) || unlikely(wc->metadata_only)) goto unlock_remap_origin; goto unlock_submit; } else { @@ -1380,7 +1381,8 @@ read_next_block: } found_entry = true; } else { - if (unlikely(wc->cleaner)) + if (unlikely(wc->cleaner) || + (wc->metadata_only && !(bio->bi_opf & REQ_META))) goto direct_write; } e = writecache_pop_from_freelist(wc, (sector_t)-1); @@ -2094,7 +2096,7 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv) struct wc_memory_superblock s; static struct dm_arg _args[] = { - {0, 16, "Invalid number of feature args"}, + {0, 17, "Invalid number of feature args"}, }; as.argc = argc; @@ -2321,6 +2323,8 @@ static int writecache_ctr(struct dm_target *ti, unsigned argc, char **argv) wc->writeback_fua = false; wc->writeback_fua_set = true; } else goto invalid_optional; + } else if (!strcasecmp(string, "metadata_only")) { + wc->metadata_only = true; } else { invalid_optional: r = -EINVAL; @@ -2544,6 +2548,8 @@ static void writecache_status(struct dm_target *ti, status_type_t type, extra_args++; if (wc->writeback_fua_set) extra_args++; + if (wc->metadata_only) + extra_args++; DMEMIT("%u", extra_args); if (wc->start_sector_set) @@ -2564,13 +2570,15 @@ static void writecache_status(struct dm_target *ti, status_type_t type, DMEMIT(" cleaner"); if (wc->writeback_fua_set) DMEMIT(" %sfua", wc->writeback_fua ? "" : "no"); + if (wc->metadata_only) + DMEMIT(" metadata_only"); break; } } static struct target_type writecache_target = { .name = "writecache", - .version = {1, 4, 0}, + .version = {1, 5, 0}, .module = THIS_MODULE, .ctr = writecache_ctr, .dtr = writecache_dtr, |