diff options
| -rw-r--r-- | block/blk-settings.c | 7 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 11 | ||||
| -rw-r--r-- | include/linux/blkdev.h | 1 |
3 files changed, 13 insertions, 6 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index 4dd59059b788..0046b447268f 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -830,10 +830,13 @@ EXPORT_SYMBOL(blk_set_queue_depth); */ void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua) { - if (wc) + if (wc) { + blk_queue_flag_set(QUEUE_FLAG_HW_WC, q); blk_queue_flag_set(QUEUE_FLAG_WC, q); - else + } else { + blk_queue_flag_clear(QUEUE_FLAG_HW_WC, q); blk_queue_flag_clear(QUEUE_FLAG_WC, q); + } if (fua) blk_queue_flag_set(QUEUE_FLAG_FUA, q); else diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c index 0cde6598fb2f..63e481262336 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -449,13 +449,16 @@ static ssize_t queue_wc_show(struct request_queue *q, char *page) static ssize_t queue_wc_store(struct request_queue *q, const char *page, size_t count) { - if (!strncmp(page, "write back", 10)) + if (!strncmp(page, "write back", 10)) { + if (!test_bit(QUEUE_FLAG_HW_WC, &q->queue_flags)) + return -EINVAL; blk_queue_flag_set(QUEUE_FLAG_WC, q); - else if (!strncmp(page, "write through", 13) || - !strncmp(page, "none", 4)) + } else if (!strncmp(page, "write through", 13) || + !strncmp(page, "none", 4)) { blk_queue_flag_clear(QUEUE_FLAG_WC, q); - else + } else { return -EINVAL; + } return count; } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index ed44a997f629..2f5371b8482c 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -538,6 +538,7 @@ struct request_queue { #define QUEUE_FLAG_ADD_RANDOM 10 /* Contributes to random pool */ #define QUEUE_FLAG_SYNCHRONOUS 11 /* always completes in submit context */ #define QUEUE_FLAG_SAME_FORCE 12 /* force complete on same CPU */ +#define QUEUE_FLAG_HW_WC 18 /* Write back caching supported */ #define QUEUE_FLAG_INIT_DONE 14 /* queue is initialized */ #define QUEUE_FLAG_STABLE_WRITES 15 /* don't modify blks until WB is done */ #define QUEUE_FLAG_POLL 16 /* IO polling enabled if set */ |