From 5b99c2ffa980528a197f26c7d876cceeccce8dd5 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 15 Aug 2008 10:56:11 +0200 Subject: [PATCH] block: make bi_phys_segments an unsigned int instead of short raid5 can overflow with more than 255 stripes, and we can increase it to an int for free on both 32 and 64-bit archs due to the padding. Signed-off-by: Jens Axboe --- drivers/md/raid5.c | 12 ++++++------ include/linux/bio.h | 2 +- 2 files changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 05b2292..37e5465 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -102,17 +102,17 @@ const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256))); #endif /* - * We maintain a biased count of active stripes in the bottom 8 bits of - * bi_phys_segments, and a count of processed stripes in the upper 8 bits + * We maintain a biased count of active stripes in the bottom 16 bits of + * bi_phys_segments, and a count of processed stripes in the upper 16 bits */ static inline int raid5_bi_phys_segments(struct bio *bio) { - return bio->bi_phys_segments & 0xff; + return bio->bi_phys_segments & 0xffff; } static inline int raid5_bi_hw_segments(struct bio *bio) { - return (bio->bi_phys_segments >> 8) & 0xff; + return (bio->bi_phys_segments >> 16) & 0xffff; } static inline int raid5_dec_bi_phys_segments(struct bio *bio) @@ -126,13 +126,13 @@ static inline int raid5_dec_bi_hw_segments(struct bio *bio) unsigned short val = raid5_bi_hw_segments(bio); --val; - bio->bi_phys_segments = (val << 8) | raid5_bi_phys_segments(bio); + bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio); return val; } static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt) { - bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 8); + bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 16); } static inline int raid6_next_disk(int disk, int raid_disks) diff --git a/include/linux/bio.h b/include/linux/bio.h index dfc3556..2c0c090 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -75,7 +75,7 @@ struct bio { /* Number of segments in this BIO after * physical address coalescing is performed. */ - unsigned short bi_phys_segments; + unsigned int bi_phys_segments; unsigned int bi_size; /* residual I/O count */ -- 2.7.4