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author | Coly Li <colyli@suse.de> | 2021-06-07 15:50:51 +0300 |
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committer | Jens Axboe <axboe@kernel.dk> | 2021-06-09 00:06:03 +0300 |
commit | 1616a4c2ab1a80893b6890ae93da40a2b1d0c691 (patch) | |
tree | f758d65c79e91236d526e32701249caca58addac /drivers/md/bcache/bcache.h | |
parent | e369edbb0d8cee50efa6375d5c598a04b7cb3032 (diff) | |
download | linux-1616a4c2ab1a80893b6890ae93da40a2b1d0c691.tar.xz |
bcache: remove bcache device self-defined readahead
For read cache missing, bcache defines a readahead size for the read I/O
request to the backing device for the missing data. This readahead size
is initialized to 0, and almost no one uses it to avoid unnecessary read
amplifying onto backing device and write amplifying onto cache device.
Considering upper layer file system code has readahead logic allready
and works fine with readahead_cache_policy sysfile interface, we don't
have to keep bcache self-defined readahead anymore.
This patch removes the bcache self-defined readahead for cache missing
request for backing device, and the readahead sysfs file interfaces are
removed as well.
This is the preparation for next patch to fix potential kernel panic due
to oversized request in a simpler method.
Reported-by: Alexander Ullrich <ealex1979@gmail.com>
Reported-by: Diego Ercolani <diego.ercolani@gmail.com>
Reported-by: Jan Szubiak <jan.szubiak@linuxpolska.pl>
Reported-by: Marco Rebhan <me@dblsaiko.net>
Reported-by: Matthias Ferdinand <bcache@mfedv.net>
Reported-by: Victor Westerhuis <victor@westerhu.is>
Reported-by: Vojtech Pavlik <vojtech@suse.cz>
Reported-and-tested-by: Rolf Fokkens <rolf@rolffokkens.nl>
Reported-and-tested-by: Thorsten Knabe <linux@thorsten-knabe.de>
Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Nix <nix@esperi.org.uk>
Cc: Takashi Iwai <tiwai@suse.com>
Link: https://lore.kernel.org/r/20210607125052.21277-2-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md/bcache/bcache.h')
-rw-r--r-- | drivers/md/bcache/bcache.h | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h index 0a4551e165ab..5fc989a6d452 100644 --- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -364,7 +364,6 @@ struct cached_dev { /* The rest of this all shows up in sysfs */ unsigned int sequential_cutoff; - unsigned int readahead; unsigned int io_disable:1; unsigned int verify:1; |