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authorLinus Torvalds <torvalds@linux-foundation.org>2015-07-24 17:00:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-07-24 17:00:04 -0700
commit33b40178cb3bd75294d1a758b3f509a0d38682ab (patch)
treed5c29280f425cfbcd6f6ca247b2a776c8f787cec
parent9fbf075c96fe09719f857c5abcf7b3138f5e0855 (diff)
parentf3f5da624e0a891c34d8cd513c57f1d9b0c7dadc (diff)
downloadlinux-stericsson-33b40178cb3bd75294d1a758b3f509a0d38682ab.tar.gz
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
-rw-r--r--block/bio.c17
-rw-r--r--block/blk-cgroup.c6
-rw-r--r--drivers/block/null_blk.c18
-rw-r--r--fs/fs-writeback.c1
4 files changed, 29 insertions, 13 deletions
diff --git a/block/bio.c b/block/bio.c
index 2a00d349cd68..d6e5ba3399f0 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -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()
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 9da02c021ebe..d6283b3f5db5 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -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);
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 69de41a87b74..3177b245d2bd 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -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);
}
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index f0520bcf2094..518c6294bf6c 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -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