diff options
| author | Christoph Hellwig | 2023-07-07 11:42:39 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-09-13 09:42:40 +0200 |
| commit | 00c0b2825bb5df26c339cef1d32db6a8755de203 (patch) | |
| tree | 21140bad2e5750ca402982dcf665ee6e74a4bc67 /block | |
| parent | e5e0ec8ff16089a0801cd6a1748003697b6b901f (diff) | |
block: don't allow enabling a cache on devices that don't support it
[ Upstream commit 43c9835b144c7ce29efe142d662529662a9eb376 ]
Currently the write_cache attribute allows enabling the QUEUE_FLAG_WC
flag on devices that never claimed the capability.
Fix that by adding a QUEUE_FLAG_HW_WC flag that is set by
blk_queue_write_cache and guards re-enabling the cache through sysfs.
Note that any rescan that calls blk_queue_write_cache will still
re-enable the write cache as in the current code.
Fixes: 93e9d8e836cb ("block: add ability to flag write back caching on a device")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230707094239.107968-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-settings.c | 7 | ||||
| -rw-r--r-- | block/blk-sysfs.c | 11 |
2 files changed, 12 insertions, 6 deletions
diff --git a/block/blk-settings.c b/block/blk-settings.c index 291cf9df7fc2..86ff375c00ce 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -824,10 +824,13 @@ 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 4f34525bafac..a582ea0da74f 100644 --- a/block/blk-sysfs.c +++ b/block/blk-sysfs.c @@ -528,13 +528,16 @@ 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; } |