Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "Four smaller fixes for the current series.  This contains:

   - A fix for clones of discard bio's, that can cause data corruption.
     From Martin.

   - A fix for null_blk, where in certain queue modes it could access a
     request after it had been freed.  From Mike Krinkin.

   - An error handling leak fix for blkcg, from Tejun.

   - Also from Tejun, export of the functions that a file system needs
     to implement cgroup writeback support"

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: Do a full clone when splitting discard bios
  block: export bio_associate_*() and wbc_account_io()
  blkcg: fix gendisk reference leak in blkg_conf_prep()
  null_blk: fix use-after-free problem
This commit is contained in:
Linus Torvalds 2015-07-24 17:00:04 -07:00
commit 33b40178cb
4 changed files with 29 additions and 13 deletions

View File

@ -1831,8 +1831,9 @@ EXPORT_SYMBOL(bio_endio);
* Allocates and returns a new bio which represents @sectors from the start of
* @bio, and updates @bio to represent the remaining sectors.
*
* The newly allocated bio will point to @bio's bi_io_vec; it is the caller's
* responsibility to ensure that @bio is not freed before the split.
* Unless this is a discard request the newly allocated bio will point
* to @bio's bi_io_vec; it is the caller's responsibility to ensure that
* @bio is not freed before the split.
*/
struct bio *bio_split(struct bio *bio, int sectors,
gfp_t gfp, struct bio_set *bs)
@ -1842,7 +1843,15 @@ struct bio *bio_split(struct bio *bio, int sectors,
BUG_ON(sectors <= 0);
BUG_ON(sectors >= bio_sectors(bio));
split = bio_clone_fast(bio, gfp, bs);
/*
* Discards need a mutable bio_vec to accommodate the payload
* required by the DSM TRIM and UNMAP commands.
*/
if (bio->bi_rw & REQ_DISCARD)
split = bio_clone_bioset(bio, gfp, bs);
else
split = bio_clone_fast(bio, gfp, bs);
if (!split)
return NULL;
@ -2009,6 +2018,7 @@ int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css)
bio->bi_css = blkcg_css;
return 0;
}
EXPORT_SYMBOL_GPL(bio_associate_blkcg);
/**
* bio_associate_current - associate a bio with %current
@ -2039,6 +2049,7 @@ int bio_associate_current(struct bio *bio)
bio->bi_css = task_get_css(current, blkio_cgrp_id);
return 0;
}
EXPORT_SYMBOL_GPL(bio_associate_current);
/**
* bio_disassociate_task - undo bio_associate_current()

View File

@ -718,8 +718,12 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
return -EINVAL;
disk = get_gendisk(MKDEV(major, minor), &part);
if (!disk || part)
if (!disk)
return -EINVAL;
if (part) {
put_disk(disk);
return -EINVAL;
}
rcu_read_lock();
spin_lock_irq(disk->queue->queue_lock);

View File

@ -240,19 +240,19 @@ static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer)
while ((entry = llist_del_all(&cq->list)) != NULL) {
entry = llist_reverse_order(entry);
do {
struct request_queue *q = NULL;
cmd = container_of(entry, struct nullb_cmd, ll_list);
entry = entry->next;
if (cmd->rq)
q = cmd->rq->q;
end_cmd(cmd);
if (cmd->rq) {
struct request_queue *q = cmd->rq->q;
if (!q->mq_ops && blk_queue_stopped(q)) {
spin_lock(q->queue_lock);
if (blk_queue_stopped(q))
blk_start_queue(q);
spin_unlock(q->queue_lock);
}
if (q && !q->mq_ops && blk_queue_stopped(q)) {
spin_lock(q->queue_lock);
if (blk_queue_stopped(q))
blk_start_queue(q);
spin_unlock(q->queue_lock);
}
} while (entry);
}

View File

@ -702,6 +702,7 @@ void wbc_account_io(struct writeback_control *wbc, struct page *page,
else
wbc->wb_tcand_bytes -= min(bytes, wbc->wb_tcand_bytes);
}
EXPORT_SYMBOL_GPL(wbc_account_io);
/**
* inode_congested - test whether an inode is congested