From 0034af036554c39eefd14d835a8ec3496ac46712 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 16 Jul 2015 09:14:26 -0600 Subject: block: make /sys/block//queue/discard_max_bytes writeable Lots of devices support huge discard sizes these days. Depending on how the device handles them internally, huge discards can introduce massive latencies (hundreds of msec) on the device side. We have a sysfs file, discard_max_bytes, that advertises the max hardware supported discard size. Make this writeable, and split the settings into a soft and hard limit. This can be set from 'discard_granularity' and up to the hardware limit. Add a new sysfs file, 'discard_max_hw_bytes', that shows the hw set limit. Reviewed-by: Jeff Moyer Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index d4068c17d0df..243f29e779ec 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -268,6 +268,7 @@ struct queue_limits { unsigned int io_min; unsigned int io_opt; unsigned int max_discard_sectors; + unsigned int max_hw_discard_sectors; unsigned int max_write_same_sectors; unsigned int discard_granularity; unsigned int discard_alignment; -- cgit v1.2.3 From 54efd50bfd873e2dbf784e0b21a8027ba4299a3e Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Thu, 23 Apr 2015 22:37:18 -0700 Subject: block: make generic_make_request handle arbitrarily sized bios The way the block layer is currently written, it goes to great lengths to avoid having to split bios; upper layer code (such as bio_add_page()) checks what the underlying device can handle and tries to always create bios that don't need to be split. But this approach becomes unwieldy and eventually breaks down with stacked devices and devices with dynamic limits, and it adds a lot of complexity. If the block layer could split bios as needed, we could eliminate a lot of complexity elsewhere - particularly in stacked drivers. Code that creates bios can then create whatever size bios are convenient, and more importantly stacked drivers don't have to deal with both their own bio size limitations and the limitations of the (potentially multiple) devices underneath them. In the future this will let us delete merge_bvec_fn and a bunch of other code. We do this by adding calls to blk_queue_split() to the various make_request functions that need it - a few can already handle arbitrary size bios. Note that we add the call _after_ any call to blk_queue_bounce(); this means that blk_queue_split() and blk_recalc_rq_segments() don't need to be concerned with bouncing affecting segment merging. Some make_request_fn() callbacks were simple enough to audit and verify they don't need blk_queue_split() calls. The skipped ones are: * nfhd_make_request (arch/m68k/emu/nfblock.c) * axon_ram_make_request (arch/powerpc/sysdev/axonram.c) * simdisk_make_request (arch/xtensa/platforms/iss/simdisk.c) * brd_make_request (ramdisk - drivers/block/brd.c) * mtip_submit_request (drivers/block/mtip32xx/mtip32xx.c) * loop_make_request * null_queue_bio * bcache's make_request fns Some others are almost certainly safe to remove now, but will be left for future patches. Cc: Jens Axboe Cc: Christoph Hellwig Cc: Al Viro Cc: Ming Lei Cc: Neil Brown Cc: Alasdair Kergon Cc: Mike Snitzer Cc: dm-devel@redhat.com Cc: Lars Ellenberg Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina Cc: Geoff Levand Cc: Jim Paris Cc: Philip Kelleher Cc: Minchan Kim Cc: Nitin Gupta Cc: Oleg Drokin Cc: Andreas Dilger Acked-by: NeilBrown (for the 'md/md.c' bits) Acked-by: Mike Snitzer Reviewed-by: Martin K. Petersen Signed-off-by: Kent Overstreet [dpark: skip more mq-based drivers, resolve merge conflicts, etc.] Signed-off-by: Dongsu Park Signed-off-by: Ming Lin Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 243f29e779ec..ca778d9c7d81 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -463,6 +463,7 @@ struct request_queue { struct blk_mq_tag_set *tag_set; struct list_head tag_set_list; + struct bio_set *bio_split; }; #define QUEUE_FLAG_QUEUED 1 /* uses generic tag queueing */ @@ -783,6 +784,8 @@ extern void blk_rq_unprep_clone(struct request *rq); extern int blk_insert_cloned_request(struct request_queue *q, struct request *rq); extern void blk_delay_queue(struct request_queue *, unsigned long); +extern void blk_queue_split(struct request_queue *, struct bio **, + struct bio_set *); extern void blk_recount_segments(struct request_queue *, struct bio *); extern int scsi_verify_blk_ioctl(struct block_device *, unsigned int); extern int scsi_cmd_blk_ioctl(struct block_device *, fmode_t, -- cgit v1.2.3 From 8ae126660fddbeebb9251a174e6fa45b6ad8f932 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Mon, 27 Apr 2015 23:48:34 -0700 Subject: block: kill merge_bvec_fn() completely As generic_make_request() is now able to handle arbitrarily sized bios, it's no longer necessary for each individual block driver to define its own ->merge_bvec_fn() callback. Remove every invocation completely. Cc: Jens Axboe Cc: Lars Ellenberg Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina Cc: Yehuda Sadeh Cc: Sage Weil Cc: Alex Elder Cc: ceph-devel@vger.kernel.org Cc: Alasdair Kergon Cc: Mike Snitzer Cc: dm-devel@redhat.com Cc: Neil Brown Cc: linux-raid@vger.kernel.org Cc: Christoph Hellwig Cc: "Martin K. Petersen" Acked-by: NeilBrown (for the 'md' bits) Acked-by: Mike Snitzer Signed-off-by: Kent Overstreet [dpark: also remove ->merge_bvec_fn() in dm-thin as well as dm-era-target, and resolve merge conflicts] Signed-off-by: Dongsu Park Signed-off-by: Ming Lin Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 10 ---------- 1 file changed, 10 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index ca778d9c7d81..a1feff54aeab 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -213,14 +213,6 @@ typedef int (prep_rq_fn) (struct request_queue *, struct request *); typedef void (unprep_rq_fn) (struct request_queue *, struct request *); struct bio_vec; -struct bvec_merge_data { - struct block_device *bi_bdev; - sector_t bi_sector; - unsigned bi_size; - unsigned long bi_rw; -}; -typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *, - struct bio_vec *); typedef void (softirq_done_fn)(struct request *); typedef int (dma_drain_needed_fn)(struct request *); typedef int (lld_busy_fn) (struct request_queue *q); @@ -306,7 +298,6 @@ struct request_queue { make_request_fn *make_request_fn; prep_rq_fn *prep_rq_fn; unprep_rq_fn *unprep_rq_fn; - merge_bvec_fn *merge_bvec_fn; softirq_done_fn *softirq_done_fn; rq_timed_out_fn *rq_timed_out_fn; dma_drain_needed_fn *dma_drain_needed; @@ -992,7 +983,6 @@ extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); -extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *); extern void blk_queue_dma_alignment(struct request_queue *, int); extern void blk_queue_update_dma_alignment(struct request_queue *, int); extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); -- cgit v1.2.3 From 30e2bc08b2bb7c069246feee78f7ed4006e130fe Mon Sep 17 00:00:00 2001 From: Jeff Moyer Date: Thu, 13 Aug 2015 14:57:56 -0400 Subject: Revert "block: remove artifical max_hw_sectors cap" This reverts commit 34b48db66e08ca1c1bc07cf305d672ac940268dc. That commit caused performance regressions for streaming I/O workloads on a number of different storage devices, from SATA disks to external RAID arrays. It also managed to trip up some buggy firmware in at least one drive, causing data corruption. The next patch will bump the default max_sectors_kb value to 1280, which will accommodate a 10-data-disk stripe write with chunk size 128k. In the testing I've done using iozone, fio, and aio-stress, a value of 1280 does not show a big performance difference from 512. This will hopefully still help the software RAID setup that Christoph saw the original performance gains with while still not regressing other storage configurations. Signed-off-by: Jeff Moyer Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index a1feff54aeab..9f1e3f8eeed7 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1132,6 +1132,7 @@ extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); enum blk_default_limits { BLK_MAX_SEGMENTS = 128, BLK_SAFE_MAX_SECTORS = 255, + BLK_DEF_MAX_SECTORS = 1024, BLK_MAX_SEGMENT_SIZE = 65536, BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, }; -- cgit v1.2.3 From d2be537c3ba3568acd79cd178327b842e60d035e Mon Sep 17 00:00:00 2001 From: Jeff Moyer Date: Thu, 13 Aug 2015 14:57:57 -0400 Subject: block: bump BLK_DEF_MAX_SECTORS to 2560 A value of 2560 (1280k) will accommodate a 10-data-disk stripe write with chunk size 128k. In the testing I've done using iozone, fio, and aio-stress across a number of different storage devices, a value of 1280 does not show a big performance difference from 512, but will hopefully help software RAID setups using SATA disks, as reported by Christoph. NOTE: drivers/block/aoe/aoeblk.c sets its own max_hw_sectors_kb to BLK_DEF_MAX_SECTORS. So, this patch essentially changes aeoblk to Use a larger maximum sector size, and I did not test this. Signed-off-by: Jeff Moyer Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 9f1e3f8eeed7..e427debc7008 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1132,7 +1132,7 @@ extern int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm); enum blk_default_limits { BLK_MAX_SEGMENTS = 128, BLK_SAFE_MAX_SECTORS = 255, - BLK_DEF_MAX_SECTORS = 1024, + BLK_DEF_MAX_SECTORS = 2560, BLK_MAX_SEGMENT_SIZE = 65536, BLK_SEG_BOUNDARY_MASK = 0xFFFFFFFFUL, }; -- cgit v1.2.3 From 03100aada96f0645bbcb89aea24c01f02d0ef1fa Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Wed, 19 Aug 2015 14:24:05 -0700 Subject: block: Replace SG_GAPS with new queue limits mask The SG_GAPS queue flag caused checks for bio vector alignment against PAGE_SIZE, but the device may have different constraints. This patch adds a queue limits so a driver with such constraints can set to allow requests that would have been unnecessarily split. The new gaps check takes the request_queue as a parameter to simplify the logic around invoking this function. This new limit makes the queue flag redundant, so removing it and all usage. Device-mappers will inherit the correct settings through blk_stack_limits(). Signed-off-by: Keith Busch Reviewed-by: Martin K. Petersen Reviewed-by: Christoph Hellwig Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 21 ++++++++++++++++++++- 1 file changed, 20 insertions(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index e427debc7008..a622f270f09e 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -250,6 +250,7 @@ struct blk_queue_tag { struct queue_limits { unsigned long bounce_pfn; unsigned long seg_boundary_mask; + unsigned long virt_boundary_mask; unsigned int max_hw_sectors; unsigned int chunk_sectors; @@ -479,7 +480,6 @@ struct request_queue { #define QUEUE_FLAG_DEAD 19 /* queue tear-down finished */ #define QUEUE_FLAG_INIT_DONE 20 /* queue is initialized */ #define QUEUE_FLAG_NO_SG_MERGE 21 /* don't attempt to merge SG segments*/ -#define QUEUE_FLAG_SG_GAPS 22 /* queue doesn't support SG gaps */ #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_STACKABLE) | \ @@ -981,6 +981,7 @@ extern int blk_queue_dma_drain(struct request_queue *q, void *buf, unsigned int size); extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn); extern void blk_queue_segment_boundary(struct request_queue *, unsigned long); +extern void blk_queue_virt_boundary(struct request_queue *, unsigned long); extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn); extern void blk_queue_unprep_rq(struct request_queue *, unprep_rq_fn *ufn); extern void blk_queue_dma_alignment(struct request_queue *, int); @@ -1149,6 +1150,11 @@ static inline unsigned long queue_segment_boundary(struct request_queue *q) return q->limits.seg_boundary_mask; } +static inline unsigned long queue_virt_boundary(struct request_queue *q) +{ + return q->limits.virt_boundary_mask; +} + static inline unsigned int queue_max_sectors(struct request_queue *q) { return q->limits.max_sectors; @@ -1349,6 +1355,19 @@ static inline void put_dev_sector(Sector p) page_cache_release(p.v); } +/* + * Check if adding a bio_vec after bprv with offset would create a gap in + * the SG list. Most drivers don't care about this, but some do. + */ +static inline bool bvec_gap_to_prev(struct request_queue *q, + struct bio_vec *bprv, unsigned int offset) +{ + if (!queue_virt_boundary(q)) + return false; + return offset || + ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q)); +} + struct work_struct; int kblockd_schedule_work(struct work_struct *work); int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay); -- cgit v1.2.3 From e2e05394e4a3420dab96f728df4531893494e15d Mon Sep 17 00:00:00 2001 From: Ross Zwisler Date: Tue, 18 Aug 2015 13:55:41 -0600 Subject: pmem, dax: have direct_access use __pmem annotation Update the annotation for the kaddr pointer returned by direct_access() so that it is a __pmem pointer. This is consistent with the PMEM driver and with how this direct_access() pointer is used in the DAX code. Signed-off-by: Ross Zwisler Reviewed-by: Christoph Hellwig Signed-off-by: Dan Williams --- include/linux/blkdev.h | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index d4068c17d0df..c401ecdff9cb 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1555,8 +1555,8 @@ struct block_device_operations { int (*rw_page)(struct block_device *, sector_t, struct page *, int rw); int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); - long (*direct_access)(struct block_device *, sector_t, - void **, unsigned long *pfn, long size); + long (*direct_access)(struct block_device *, sector_t, void __pmem **, + unsigned long *pfn, long size); unsigned int (*check_events) (struct gendisk *disk, unsigned int clearing); /* ->media_changed() is DEPRECATED, use ->check_events() instead */ @@ -1574,8 +1574,8 @@ extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, extern int bdev_read_page(struct block_device *, sector_t, struct page *); extern int bdev_write_page(struct block_device *, sector_t, struct page *, struct writeback_control *); -extern long bdev_direct_access(struct block_device *, sector_t, void **addr, - unsigned long *pfn, long size); +extern long bdev_direct_access(struct block_device *, sector_t, + void __pmem **addr, unsigned long *pfn, long size); #else /* CONFIG_BLOCK */ struct block_device; -- cgit v1.2.3 From cb389b9c0e00c30c9daf20287f7d91e2466edbb1 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 7 Aug 2015 17:41:00 -0400 Subject: dax: drop size parameter to ->direct_access() None of the implementations currently use it. The common bdev_direct_access() entry point handles all the size checks before calling ->direct_access(). Signed-off-by: Christoph Hellwig Signed-off-by: Dan Williams --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index c401ecdff9cb..c22064f326b2 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1556,7 +1556,7 @@ struct block_device_operations { int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); long (*direct_access)(struct block_device *, sector_t, void __pmem **, - unsigned long *pfn, long size); + unsigned long *pfn); unsigned int (*check_events) (struct gendisk *disk, unsigned int clearing); /* ->media_changed() is DEPRECATED, use ->check_events() instead */ -- cgit v1.2.3 From 5e7c4274a70aa2d6f485996d0ca1dad52d0039ca Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 3 Sep 2015 19:28:20 +0300 Subject: block: Check for gaps on front and back merges We are checking for gaps to previous bio_vec, which can only detect back merges gaps. Moreover, at the point where we check for a gap, we don't know if we will attempt a back or a front merge. Thus, check for gap to prev in a back merge attempt and check for a gap to next in a front merge attempt. Signed-off-by: Jens Axboe [sagig: Minor rename change] Signed-off-by: Sagi Grimberg --- include/linux/blkdev.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index a622f270f09e..2ff94def041e 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1368,6 +1368,26 @@ static inline bool bvec_gap_to_prev(struct request_queue *q, ((bprv->bv_offset + bprv->bv_len) & queue_virt_boundary(q)); } +static inline bool bio_will_gap(struct request_queue *q, struct bio *prev, + struct bio *next) +{ + if (!bio_has_data(prev)) + return false; + + return bvec_gap_to_prev(q, &prev->bi_io_vec[prev->bi_vcnt - 1], + next->bi_io_vec[0].bv_offset); +} + +static inline bool req_gap_back_merge(struct request *req, struct bio *bio) +{ + return bio_will_gap(req->q, req->biotail, bio); +} + +static inline bool req_gap_front_merge(struct request *req, struct bio *bio) +{ + return bio_will_gap(req->q, bio, req->bio); +} + struct work_struct; int kblockd_schedule_work(struct work_struct *work); int kblockd_schedule_delayed_work(struct delayed_work *dwork, unsigned long delay); -- cgit v1.2.3 From 7f39add3b08cbbdb99abe50e6d7c342e6800d684 Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Fri, 11 Sep 2015 09:03:04 -0600 Subject: block: Refuse request/bio merges with gaps in the integrity payload If a driver sets the block queue virtual boundary mask, it means that it cannot handle gaps so we must not allow those in the integrity payload as well. Signed-off-by: Sagi Grimberg Fixed up by me to have duplicate integrity merge functions, depending on whether block integrity is enabled or not. Fixes a compilations issue with CONFIG_BLK_DEV_INTEGRITY unset. Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 2ff94def041e..1aac7316a4b5 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1514,6 +1514,26 @@ queue_max_integrity_segments(struct request_queue *q) return q->limits.max_integrity_segments; } +static inline bool integrity_req_gap_back_merge(struct request *req, + struct bio *next) +{ + struct bio_integrity_payload *bip = bio_integrity(req->bio); + struct bio_integrity_payload *bip_next = bio_integrity(next); + + return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1], + bip_next->bip_vec[0].bv_offset); +} + +static inline bool integrity_req_gap_front_merge(struct request *req, + struct bio *bio) +{ + struct bio_integrity_payload *bip = bio_integrity(bio); + struct bio_integrity_payload *bip_next = bio_integrity(req->bio); + + return bvec_gap_to_prev(req->q, &bip->bip_vec[bip->bip_vcnt - 1], + bip_next->bip_vec[0].bv_offset); +} + #else /* CONFIG_BLK_DEV_INTEGRITY */ struct bio; @@ -1580,6 +1600,16 @@ static inline bool blk_integrity_is_initialized(struct gendisk *g) { return 0; } +static inline bool integrity_req_gap_back_merge(struct request *req, + struct bio *next) +{ + return false; +} +static inline bool integrity_req_gap_front_merge(struct request *req, + struct bio *bio) +{ + return false; +} #endif /* CONFIG_BLK_DEV_INTEGRITY */ -- cgit v1.2.3 From 10fbd36e362a0f367e34a7cd876a81295d8fc5ca Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 27 May 2015 15:32:15 -0700 Subject: blk: rq_data_dir() should not return a boolean MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit rq_data_dir() returns either READ or WRITE (0 == READ, 1 == WRITE), not a boolean value. Now, admittedly the "!= 0" doesn't really change the value (0 stays as zero, 1 stays as one), but it's not only redundant, it confuses gcc, and causes gcc to warn about the construct switch (rq_data_dir(req)) { case READ: ... case WRITE: ... that we have in a few drivers. Now, the gcc warning is silly and stupid (it seems to warn not about the switch value having a different type from the case statements, but about _any_ boolean switch value), but in this case the code itself is silly and stupid too, so let's just change it, and get rid of warnings like this: drivers/block/hd.c: In function ‘hd_request’: drivers/block/hd.c:630:11: warning: switch condition has boolean value [-Wswitch-bool] switch (rq_data_dir(req)) { The odd '!= 0' came in when "cmd_flags" got turned into a "u64" in commit 5953316dbf90 ("block: make rq->cmd_flags be 64-bit") and is presumably because the old code (that just did a logical 'and' with 1) would then end up making the type of rq_data_dir() be u64 too. But if we want to retain the old regular integer type, let's just cast the result to 'int' rather than use that rather odd '!= 0'. Signed-off-by: Linus Torvalds --- include/linux/blkdev.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/blkdev.h') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 708923b9b623..38a5ff772a37 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -584,7 +584,7 @@ static inline void queue_flag_clear(unsigned int flag, struct request_queue *q) #define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist) -#define rq_data_dir(rq) (((rq)->cmd_flags & 1) != 0) +#define rq_data_dir(rq) ((int)((rq)->cmd_flags & 1)) /* * Driver can handle struct request, if it either has an old style -- cgit v1.2.3