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| author | Christoph Hellwig <hch@lst.de> | 2023-07-07 11:42:39 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-07-17 08:18:18 -0600 |
| commit | 43c9835b144c7ce29efe142d662529662a9eb376 (patch) | |
| tree | 9a76f7e28e76f520ceb20966493710c10bcc49cb /include/linux/blkdev.h | |
| parent | c4e21bcd0f9d01f9c5d6c52007f5541871a5b1de (diff) | |
| download | linux-43c9835b144c7ce29efe142d662529662a9eb376.tar.gz linux-43c9835b144c7ce29efe142d662529662a9eb376.tar.bz2 linux-43c9835b144c7ce29efe142d662529662a9eb376.zip | |
block: don't allow enabling a cache on devices that don't support it
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>
Diffstat (limited to 'include/linux/blkdev.h')
| -rw-r--r-- | include/linux/blkdev.h | 1 |
1 files changed, 1 insertions, 0 deletions
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 */ |