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| author |   Ming Lei <ming.lei@redhat.com> | 2020-05-08 16:17:56 +0800 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2020-05-12 20:31:39 -0600 |
| commit | 07c4e1e834f8e7c991aa6dcb5ee0b7f2842e495d (patch) | |
| tree | 0c1fd4194b7af7d096e73834fde80cce5bb4ba64 | |
| parent | block: fix use-after-free on cached last_lookup partition (diff) | |
| download | linux-dev-07c4e1e834f8e7c991aa6dcb5ee0b7f2842e495d.tar.xz linux-dev-07c4e1e834f8e7c991aa6dcb5ee0b7f2842e495d.zip | |
block: only define 'nr_sects_seq' in hd_part for 32bit SMP
The seqcount of 'nr_sects_seq' is only needed in case of 32bit SMP,
so define it just for 32bit SMP.
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Cc: Yufen Yu <yuyufen@huawei.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Hou Tao <houtao1@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/genhd.c | 2 | ||||
| -rw-r--r-- | block/partitions/core.c | 2 | ||||
| -rw-r--r-- | include/linux/genhd.h | 9 |
3 files changed, 11 insertions, 2 deletions
diff --git a/block/genhd.c b/block/genhd.c index af6cba2a9332..1a51a9ad1035 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1731,7 +1731,7 @@ struct gendisk *__alloc_disk_node(int minors, int node_id) * TODO: Ideally set_capacity() and get_capacity() should be * converted to make use of bd_mutex and sequence counters. */ - seqcount_init(&disk->part0.nr_sects_seq); + hd_sects_seq_init(&disk->part0); if (hd_ref_init(&disk->part0)) { hd_free_part(&disk->part0); kfree(disk); diff --git a/block/partitions/core.c b/block/partitions/core.c index 8d8c87207fc2..297004fd2264 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -392,7 +392,7 @@ static struct hd_struct *add_partition(struct gendisk *disk, int partno, goto out_free; } - seqcount_init(&p->nr_sects_seq); + hd_sects_seq_init(p); pdev = part_to_dev(p); p->start_sect = start; diff --git a/include/linux/genhd.h b/include/linux/genhd.h index f9c226f9546a..b4744035ae58 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -68,7 +68,9 @@ struct hd_struct { * can be non-atomic on 32bit machines with 64bit sector_t. */ sector_t nr_sects; +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) seqcount_t nr_sects_seq; +#endif sector_t alignment_offset; unsigned int discard_alignment; struct device __dev; @@ -274,6 +276,13 @@ static inline void disk_put_part(struct hd_struct *part) put_device(part_to_dev(part)); } +static inline void hd_sects_seq_init(struct hd_struct *p) +{ +#if BITS_PER_LONG==32 && defined(CONFIG_SMP) + seqcount_init(&p->nr_sects_seq); +#endif +} + /* * Smarter partition iterator without context limits. */ |