From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f173.google.com ([209.85.223.173]:34849 "EHLO mail-io0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751454AbdFZPiL (ORCPT ); Mon, 26 Jun 2017 11:38:11 -0400 Received: by mail-io0-f173.google.com with SMTP id h134so2976654iof.2 for ; Mon, 26 Jun 2017 08:38:11 -0700 (PDT) From: Jens Axboe To: linux-block@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, hch@lst.de, martin.petersen@oracle.com, Jens Axboe Subject: [PATCH 2/9] block: add support for write hints in a bio Date: Mon, 26 Jun 2017 09:37:53 -0600 Message-Id: <1498491480-16306-3-git-send-email-axboe@kernel.dk> In-Reply-To: <1498491480-16306-1-git-send-email-axboe@kernel.dk> References: <1498491480-16306-1-git-send-email-axboe@kernel.dk> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: No functional changes in this patch, we just set aside 3 bits in the bio/request flags, which can be used to hold a WRITE_LIFE_* life time hint. Ensure that we don't merge requests that have different life time hints assigned to them. Reviewed-by: Martin K. Petersen Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-merge.c | 16 ++++++++++++++++ fs/inode.c | 9 +++++++++ include/linux/blk_types.h | 31 +++++++++++++++++++++++++++++++ include/linux/fs.h | 2 ++ 4 files changed, 58 insertions(+) diff --git a/block/blk-merge.c b/block/blk-merge.c index 5df13041b851..be1e955db75e 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -673,6 +673,14 @@ static struct request *attempt_merge(struct request_queue *q, return NULL; /* + * Don't allow merge of different write hints, or for a hint with + * non-hint IO. + */ + if ((req->cmd_flags & REQ_WRITE_LIFE_MASK) != + (next->cmd_flags & REQ_WRITE_LIFE_MASK)) + return NULL; + + /* * If we are allowed to merge, then append bio list * from next to rq and release next. merge_requests_fn * will have updated segment counts, update sector @@ -791,6 +799,14 @@ bool blk_rq_merge_ok(struct request *rq, struct bio *bio) !blk_write_same_mergeable(rq->bio, bio)) return false; + /* + * Don't allow merge of different write hints, or for a hint with + * non-hint IO. + */ + if ((rq->cmd_flags & REQ_WRITE_LIFE_MASK) != + (bio->bi_opf & REQ_WRITE_LIFE_MASK)) + return false; + return true; } diff --git a/fs/inode.c b/fs/inode.c index defb015a2c6d..66cc431c9a96 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -2131,3 +2131,12 @@ void inode_set_write_hint(struct inode *inode, enum rw_hint hint) inode_unlock(inode); } } + +/* + * Returns block write hint mask for the inode + */ +unsigned int inode_hint_to_opf(struct inode *inode) +{ + return write_hint_to_opf(inode_write_hint(inode)); +} +EXPORT_SYMBOL(inode_hint_to_opf); diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index e210da6d14b8..0d44dce19d9f 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -7,6 +7,7 @@ #include #include +#include struct bio_set; struct bio; @@ -223,6 +224,10 @@ enum req_flag_bits { __REQ_RAHEAD, /* read ahead, can fail anytime */ __REQ_BACKGROUND, /* background IO */ + __REQ_WRITE_HINT_SHIFT, /* 3 bits for life time hint */ + __REQ_WRITE_HINT_PAD1, + __REQ_WRITE_HINT_PAD2, + /* command specific flags for REQ_OP_WRITE_ZEROES: */ __REQ_NOUNMAP, /* do not free blocks when zeroing */ @@ -244,6 +249,13 @@ enum req_flag_bits { #define REQ_RAHEAD (1ULL << __REQ_RAHEAD) #define REQ_BACKGROUND (1ULL << __REQ_BACKGROUND) +#define REQ_WRITE_SHORT (WRITE_LIFE_SHORT << __REQ_WRITE_HINT_SHIFT) +#define REQ_WRITE_MEDIUM (WRITE_LIFE_MEDIUM << __REQ_WRITE_HINT_SHIFT) +#define REQ_WRITE_LONG (WRITE_LIFE_LONG << __REQ_WRITE_HINT_SHIFT) +#define REQ_WRITE_EXTREME (WRITE_LIFE_EXTREME << __REQ_WRITE_HINT_SHIFT) + +#define REQ_WRITE_LIFE_MASK (0x7 << __REQ_WRITE_HINT_SHIFT) + #define REQ_NOUNMAP (1ULL << __REQ_NOUNMAP) #define REQ_NOWAIT (1ULL << __REQ_NOWAIT) @@ -335,4 +347,23 @@ struct blk_rq_stat { u64 batch; }; +static inline unsigned int write_hint_to_opf(enum rw_hint hint) +{ + return hint << __REQ_WRITE_HINT_SHIFT; +} + +/* + * Don't let drivers see WRITE_LIFE_NOT_SET, return NONE for that + */ +static inline enum rw_hint opf_to_write_hint(unsigned int opf) +{ + enum rw_hint ret; + + ret = (opf & REQ_WRITE_LIFE_MASK) >> __REQ_WRITE_HINT_SHIFT; + if (ret == WRITE_LIFE_NOT_SET) + ret = WRITE_LIFE_NONE; + + return ret; +} + #endif /* __LINUX_BLK_TYPES_H */ diff --git a/include/linux/fs.h b/include/linux/fs.h index 0ef5d110d2bc..86888a6ccad1 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1912,6 +1912,8 @@ static inline bool HAS_UNMAPPED_ID(struct inode *inode) return !uid_valid(inode->i_uid) || !gid_valid(inode->i_gid); } +extern unsigned int inode_hint_to_opf(struct inode *inode); + static inline unsigned int write_hint_to_mask(enum rw_hint hint, unsigned int shift) { -- 2.7.4