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authorChristoph Hellwig <hch@lst.de>2021-08-16 15:46:24 +0200
committerJens Axboe <axboe@kernel.dk>2021-08-23 12:54:31 -0600
commitd152c682f03ceb65c0d9663d4ba6ee2d46aa784d (patch)
tree31cc1a85256072b4d65d881472c2f6ace7c10178 /block
parent61a35cfc26334fe1c8e970ca8fafeae2daae257d (diff)
downloadlinux-d152c682f03ceb65c0d9663d4ba6ee2d46aa784d.tar.bz2
block: add an explicit ->disk backpointer to the request_queue
Replace the magic lookup through the kobject tree with an explicit backpointer, given that the device model links are set up and torn down at times when I/O is still possible, leading to potential NULL or invalid pointer dereferences. Fixes: edb0872f44ec ("block: move the bdi from the request_queue to the gendisk") Reported-by: syzbot <syzbot+aa0801b6b32dca9dda82@syzkaller.appspotmail.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Sven Schnelle <svens@linux.ibm.com> Link: https://lore.kernel.org/r/20210816134624.GA24234@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
-rw-r--r--block/bfq-iosched.c2
-rw-r--r--block/blk-cgroup.c4
-rw-r--r--block/blk-mq.c2
-rw-r--r--block/blk-settings.c8
-rw-r--r--block/blk-sysfs.c13
-rw-r--r--block/blk-wbt.c10
-rw-r--r--block/genhd.c2
7 files changed, 21 insertions, 20 deletions
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index e92bc0348433..480e1a134859 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5269,7 +5269,7 @@ bfq_set_next_ioprio_data(struct bfq_queue *bfqq, struct bfq_io_cq *bic)
switch (ioprio_class) {
default:
pr_err("bdi %s: bfq: bad prio class %d\n",
- bdi_dev_name(queue_to_disk(bfqq->bfqd->queue)->bdi),
+ bdi_dev_name(bfqq->bfqd->queue->disk->bdi),
ioprio_class);
fallthrough;
case IOPRIO_CLASS_NONE:
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index b8ec47dcce42..f575aa42922b 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -489,9 +489,9 @@ static int blkcg_reset_stats(struct cgroup_subsys_state *css,
const char *blkg_dev_name(struct blkcg_gq *blkg)
{
- if (!queue_has_disk(blkg->q) || !queue_to_disk(blkg->q)->bdi->dev)
+ if (!blkg->q->disk || !blkg->q->disk->bdi->dev)
return NULL;
- return bdi_dev_name(queue_to_disk(blkg->q)->bdi);
+ return bdi_dev_name(blkg->q->disk->bdi);
}
/**
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 2ca7e7c94b18..0a33d16a7298 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -525,7 +525,7 @@ void blk_mq_free_request(struct request *rq)
__blk_mq_dec_active_requests(hctx);
if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq)))
- laptop_io_completion(queue_to_disk(q)->bdi);
+ laptop_io_completion(q->disk->bdi);
rq_qos_done(q, rq);
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 3613d2cc0688..a7c857ad7d10 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -141,9 +141,9 @@ void blk_queue_max_hw_sectors(struct request_queue *q, unsigned int max_hw_secto
limits->logical_block_size >> SECTOR_SHIFT);
limits->max_sectors = max_sectors;
- if (!queue_has_disk(q))
+ if (!q->disk)
return;
- queue_to_disk(q)->bdi->io_pages = max_sectors >> (PAGE_SHIFT - 9);
+ q->disk->bdi->io_pages = max_sectors >> (PAGE_SHIFT - 9);
}
EXPORT_SYMBOL(blk_queue_max_hw_sectors);
@@ -475,9 +475,9 @@ EXPORT_SYMBOL(blk_limits_io_opt);
void blk_queue_io_opt(struct request_queue *q, unsigned int opt)
{
blk_limits_io_opt(&q->limits, opt);
- if (!queue_has_disk(q))
+ if (!q->disk)
return;
- queue_to_disk(q)->bdi->ra_pages =
+ q->disk->bdi->ra_pages =
max(queue_io_opt(q) * 2 / PAGE_SIZE, VM_READAHEAD_PAGES);
}
EXPORT_SYMBOL(blk_queue_io_opt);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 586507a5b8c2..7fd99487300c 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -90,9 +90,9 @@ static ssize_t queue_ra_show(struct request_queue *q, char *page)
{
unsigned long ra_kb;
- if (!queue_has_disk(q))
+ if (!q->disk)
return -EINVAL;
- ra_kb = queue_to_disk(q)->bdi->ra_pages << (PAGE_SHIFT - 10);
+ ra_kb = q->disk->bdi->ra_pages << (PAGE_SHIFT - 10);
return queue_var_show(ra_kb, page);
}
@@ -102,12 +102,12 @@ queue_ra_store(struct request_queue *q, const char *page, size_t count)
unsigned long ra_kb;
ssize_t ret;
- if (!queue_has_disk(q))
+ if (!q->disk)
return -EINVAL;
ret = queue_var_store(&ra_kb, page, count);
if (ret < 0)
return ret;
- queue_to_disk(q)->bdi->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
+ q->disk->bdi->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
return ret;
}
@@ -254,9 +254,8 @@ queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
spin_lock_irq(&q->queue_lock);
q->limits.max_sectors = max_sectors_kb << 1;
- if (queue_has_disk(q))
- queue_to_disk(q)->bdi->io_pages =
- max_sectors_kb >> (PAGE_SHIFT - 10);
+ if (q->disk)
+ q->disk->bdi->io_pages = max_sectors_kb >> (PAGE_SHIFT - 10);
spin_unlock_irq(&q->queue_lock);
return ret;
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 31086afaad9c..874c1c37bf0c 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -97,7 +97,7 @@ static void wb_timestamp(struct rq_wb *rwb, unsigned long *var)
*/
static bool wb_recent_wait(struct rq_wb *rwb)
{
- struct bdi_writeback *wb = &queue_to_disk(rwb->rqos.q)->bdi->wb;
+ struct bdi_writeback *wb = &rwb->rqos.q->disk->bdi->wb;
return time_before(jiffies, wb->dirty_sleep + HZ);
}
@@ -234,7 +234,7 @@ enum {
static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat)
{
- struct backing_dev_info *bdi = queue_to_disk(rwb->rqos.q)->bdi;
+ struct backing_dev_info *bdi = rwb->rqos.q->disk->bdi;
struct rq_depth *rqd = &rwb->rq_depth;
u64 thislat;
@@ -287,7 +287,7 @@ static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat)
static void rwb_trace_step(struct rq_wb *rwb, const char *msg)
{
- struct backing_dev_info *bdi = queue_to_disk(rwb->rqos.q)->bdi;
+ struct backing_dev_info *bdi = rwb->rqos.q->disk->bdi;
struct rq_depth *rqd = &rwb->rq_depth;
trace_wbt_step(bdi, msg, rqd->scale_step, rwb->cur_win_nsec,
@@ -359,8 +359,8 @@ static void wb_timer_fn(struct blk_stat_callback *cb)
status = latency_exceeded(rwb, cb->stat);
- trace_wbt_timer(queue_to_disk(rwb->rqos.q)->bdi, status,
- rqd->scale_step, inflight);
+ trace_wbt_timer(rwb->rqos.q->disk->bdi, status, rqd->scale_step,
+ inflight);
/*
* If we exceeded the latency target, step down. If we did not,
diff --git a/block/genhd.c b/block/genhd.c
index 6294517cebe6..02cd9ec93e52 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1078,6 +1078,7 @@ static void disk_release(struct device *dev)
disk_release_events(disk);
kfree(disk->random);
xa_destroy(&disk->part_tbl);
+ disk->queue->disk = NULL;
blk_put_queue(disk->queue);
iput(disk->part0->bd_inode); /* frees the disk */
}
@@ -1276,6 +1277,7 @@ struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
device_initialize(disk_to_dev(disk));
inc_diskseq(disk);
disk->queue = q;
+ q->disk = disk;
lockdep_init_map(&disk->lockdep_map, "(bio completion)", lkclass, 0);
#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
INIT_LIST_HEAD(&disk->slave_bdevs);