goto skip;
/*
- * Flag for bypass if the IO is for read-ahead or background,
- * unless the read-ahead request is for metadata
+ * If the bio is for read-ahead or background IO, bypass it or
+ * not depends on the following situations,
+ * - If the IO is for meta data, always cache it and no bypass
+ * - If the IO is not meta data, check dc->cache_reada_policy,
+ * BCH_CACHE_READA_ALL: cache it and not bypass
+ * BCH_CACHE_READA_META_ONLY: not cache it and bypass
+ * That is, read-ahead request for metadata always get cached
* (eg, for gfs2 or xfs).
*/
- if (bio->bi_opf & (REQ_RAHEAD|REQ_BACKGROUND) &&
- !(bio->bi_opf & (REQ_META|REQ_PRIO)))
- goto skip;
+ if ((bio->bi_opf & (REQ_RAHEAD|REQ_BACKGROUND))) {
+ if (!(bio->bi_opf & (REQ_META|REQ_PRIO)) &&
+ (dc->cache_readahead_policy != BCH_CACHE_READA_ALL))
+ goto skip;
+ }
if (bio->bi_iter.bi_sector & (c->sb.block_size - 1) ||
bio_sectors(bio) & (c->sb.block_size - 1)) {
NULL
};
+static const char * const bch_reada_cache_policies[] = {
+ "all",
+ "meta-only",
+ NULL
+};
+
/* Default is 0 ("auto") */
static const char * const bch_stop_on_failure_modes[] = {
"auto",
rw_attribute(sequential_cutoff);
rw_attribute(data_csum);
rw_attribute(cache_mode);
+rw_attribute(readahead_cache_policy);
rw_attribute(stop_when_cache_set_failed);
rw_attribute(writeback_metadata);
rw_attribute(writeback_running);
bch_cache_modes,
BDEV_CACHE_MODE(&dc->sb));
+ if (attr == &sysfs_readahead_cache_policy)
+ return bch_snprint_string_list(buf, PAGE_SIZE,
+ bch_reada_cache_policies,
+ dc->cache_readahead_policy);
+
if (attr == &sysfs_stop_when_cache_set_failed)
return bch_snprint_string_list(buf, PAGE_SIZE,
bch_stop_on_failure_modes,
}
}
+ if (attr == &sysfs_readahead_cache_policy) {
+ v = __sysfs_match_string(bch_reada_cache_policies, -1, buf);
+ if (v < 0)
+ return v;
+
+ if ((unsigned int) v != dc->cache_readahead_policy)
+ dc->cache_readahead_policy = v;
+ }
+
if (attr == &sysfs_stop_when_cache_set_failed) {
v = __sysfs_match_string(bch_stop_on_failure_modes, -1, buf);
if (v < 0)
&sysfs_data_csum,
#endif
&sysfs_cache_mode,
+ &sysfs_readahead_cache_policy,
&sysfs_stop_when_cache_set_failed,
&sysfs_writeback_metadata,
&sysfs_writeback_running,