diff options
| author | Bart Van Assche <bart.vanassche@wdc.com> | 2017-08-17 16:23:06 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2017-08-18 08:36:58 -0600 |
| commit | 6d2cf6f2b446c4ace6f57402713ddbc09b11b0a9 (patch) | |
| tree | 00de4770e862d2d130a8c1260400dbbd3a56230e /block/partition-generic.c | |
| parent | f846593391d86289bed6b4834a9717820561d571 (diff) | |
genhd: Annotate all part and part_tbl pointer dereferences
Annotate gendisk.part_tbl and disk_part_tbl.part dereferences with
rcu_dereference_protected(). This patch does not change the behavior
of the modified code but ensures that sparse does not complain about
disk->part_tbl manipulations nor about part_tbl->part accesses.
Additionally, improve documentation of the locking requirements of
the modified functions.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/partition-generic.c')
| -rw-r--r-- | block/partition-generic.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/block/partition-generic.c b/block/partition-generic.c index fa5049a4d99b..1745a9659517 100644 --- a/block/partition-generic.c +++ b/block/partition-generic.c @@ -252,15 +252,20 @@ void __delete_partition(struct percpu_ref *ref) call_rcu(&part->rcu_head, delete_partition_rcu_cb); } +/* + * Must be called either with bd_mutex held, before a disk can be opened or + * after all disk users are gone. + */ void delete_partition(struct gendisk *disk, int partno) { - struct disk_part_tbl *ptbl = disk->part_tbl; + struct disk_part_tbl *ptbl = + rcu_dereference_protected(disk->part_tbl, 1); struct hd_struct *part; if (partno >= ptbl->len) return; - part = ptbl->part[partno]; + part = rcu_dereference_protected(ptbl->part[partno], 1); if (!part) return; @@ -280,6 +285,10 @@ static ssize_t whole_disk_show(struct device *dev, static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH, whole_disk_show, NULL); +/* + * Must be called either with bd_mutex held, before a disk can be opened or + * after all disk users are gone. + */ struct hd_struct *add_partition(struct gendisk *disk, int partno, sector_t start, sector_t len, int flags, struct partition_meta_info *info) @@ -295,7 +304,7 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno, err = disk_expand_part_tbl(disk, partno); if (err) return ERR_PTR(err); - ptbl = disk->part_tbl; + ptbl = rcu_dereference_protected(disk->part_tbl, 1); if (ptbl->part[partno]) return ERR_PTR(-EBUSY); |