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| author | Mike Snitzer <snitzer@redhat.com> | 2020-01-27 14:07:23 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-11 04:34:04 -0800 |
| commit | 9eb75d69e924722c3b062359f266073935ae0cf0 (patch) | |
| tree | 953531cc1b468aa1e3a9523e0685d3ad790763a5 /drivers | |
| parent | 607d7cf285f75a5f57207b141398bec4888b3758 (diff) | |
| download | linux-stable-9eb75d69e924722c3b062359f266073935ae0cf0.tar.gz linux-stable-9eb75d69e924722c3b062359f266073935ae0cf0.tar.bz2 linux-stable-9eb75d69e924722c3b062359f266073935ae0cf0.zip | |
dm: fix potential for q->make_request_fn NULL pointer
commit 47ace7e012b9f7ad71d43ac9063d335ea3d6820b upstream.
Move blk_queue_make_request() to dm.c:alloc_dev() so that
q->make_request_fn is never NULL during the lifetime of a DM device
(even one that is created without a DM table).
Otherwise generic_make_request() will crash simply by doing:
dmsetup create -n test
mount /dev/dm-N /mnt
While at it, move ->congested_data initialization out of
dm.c:alloc_dev() and into the bio-based specific init method.
Reported-by: Stefan Bader <stefan.bader@canonical.com>
BugLink: https://bugs.launchpad.net/bugs/1860231
Fixes: ff36ab34583a ("dm: remove request-based logic from make_request_fn wrapper")
Depends-on: c12c9a3c3860c ("dm: various cleanups to md->queue initialization code")
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/md/dm.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index c9860e3b04dd..3965f3cf8ea1 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1819,6 +1819,7 @@ static void dm_init_normal_md_queue(struct mapped_device *md) /* * Initialize aspects of queue that aren't relevant for blk-mq */ + md->queue->backing_dev_info->congested_data = md; md->queue->backing_dev_info->congested_fn = dm_any_congested; } @@ -1913,7 +1914,12 @@ static struct mapped_device *alloc_dev(int minor) if (!md->queue) goto bad; md->queue->queuedata = md; - md->queue->backing_dev_info->congested_data = md; + /* + * default to bio-based required ->make_request_fn until DM + * table is loaded and md->type established. If request-based + * table is loaded: blk-mq will override accordingly. + */ + blk_queue_make_request(md->queue, dm_make_request); md->disk = alloc_disk_node(1, md->numa_node_id); if (!md->disk) @@ -2242,7 +2248,6 @@ int dm_setup_md_queue(struct mapped_device *md, struct dm_table *t) case DM_TYPE_BIO_BASED: case DM_TYPE_DAX_BIO_BASED: dm_init_normal_md_queue(md); - blk_queue_make_request(md->queue, dm_make_request); break; case DM_TYPE_NVME_BIO_BASED: dm_init_normal_md_queue(md); |