diff options
| author | Jeff Mahoney <jeffm@suse.com> | 2006-06-26 00:27:25 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-26 09:58:35 -0700 |
| commit | 10da4f795f965f22039aa2930b6f80964aad3ee5 (patch) | |
| tree | 6f4bfd27cdcdad15b53df997476fae539383bf4a /drivers/md/dm.c | |
| parent | 7ec75f254742766eb729f1d1024a5b4e6692fc5f (diff) | |
| download | linux-10da4f795f965f22039aa2930b6f80964aad3ee5.tar.bz2 | |
[PATCH] dm: add module ref counting
The reference counting on dm-mod is zero if no mapped devices are open. This
is incorrect, and can lead to an oops if the module is unloaded while mapped
devices exist.
This patch claims a reference to the module whenever a device is created, and
drops it again when the device is freed.
Devices must be removed before dm-mod is unloaded.
[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/md/dm.c')
| -rw-r--r-- | drivers/md/dm.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c index a5cc4c8462f3..29af584ae838 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -852,6 +852,9 @@ static struct mapped_device *alloc_dev(unsigned int minor, int persistent) return NULL; } + if (!try_module_get(THIS_MODULE)) + goto bad0; + /* get a minor number for the dev */ r = persistent ? specific_minor(md, minor) : next_free_minor(md, &minor); if (r < 0) @@ -918,6 +921,8 @@ static struct mapped_device *alloc_dev(unsigned int minor, int persistent) blk_cleanup_queue(md->queue); free_minor(minor); bad1: + module_put(THIS_MODULE); + bad0: kfree(md); return NULL; } @@ -941,6 +946,7 @@ static void free_dev(struct mapped_device *md) put_disk(md->disk); blk_cleanup_queue(md->queue); + module_put(THIS_MODULE); kfree(md); } |