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authorJonathan Brassow <jbrassow@redhat.com>2013-03-07 23:24:26 +0100
committerNeilBrown <neilb@suse.de>2013-03-20 03:17:57 +0100
commit90584fc93d461520a888f691144f0879283b3624 (patch)
treeb29d3af3e2af5ff3e3761525de851d88f102f9e5 /drivers/md
parentMD RAID5: Avoid accessing gendisk or queue structs when not available (diff)
downloadlinux-90584fc93d461520a888f691144f0879283b3624.tar.xz
linux-90584fc93d461520a888f691144f0879283b3624.zip
MD: Prevent sysfs operations on uninitialized kobjects
MD: Prevent sysfs operations on uninitialized kobjects Device-mapper does not use sysfs; but when device-mapper is leveraging MD's RAID personalities, MD sometimes attempts to update sysfs. This patch adds checks for 'mddev-kobj.sd' in sysfs_[un]link_rdev to ensure it is about to operate on something valid. This patch also checks for 'mddev->kobj.sd' before calling 'sysfs_notify' in 'remove_and_add_spares'. Although 'sysfs_notify' already makes this check, doing so in 'remove_and_add_spares' prevents an additional mutex operation. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'drivers/md')
-rw-r--r--drivers/md/md.c6
-rw-r--r--drivers/md/md.h4
2 files changed, 4 insertions, 6 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index fcb878f88796..aeceedfc530b 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7663,10 +7663,8 @@ static int remove_and_add_spares(struct mddev *mddev)
removed++;
}
}
- if (removed)
- sysfs_notify(&mddev->kobj, NULL,
- "degraded");
-
+ if (removed && mddev->kobj.sd)
+ sysfs_notify(&mddev->kobj, NULL, "degraded");
rdev_for_each(rdev, mddev) {
if (rdev->raid_disk >= 0 &&
diff --git a/drivers/md/md.h b/drivers/md/md.h
index eca59c3074ef..d90fb1a879e1 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -506,7 +506,7 @@ static inline char * mdname (struct mddev * mddev)
static inline int sysfs_link_rdev(struct mddev *mddev, struct md_rdev *rdev)
{
char nm[20];
- if (!test_bit(Replacement, &rdev->flags)) {
+ if (!test_bit(Replacement, &rdev->flags) && mddev->kobj.sd) {
sprintf(nm, "rd%d", rdev->raid_disk);
return sysfs_create_link(&mddev->kobj, &rdev->kobj, nm);
} else
@@ -516,7 +516,7 @@ static inline int sysfs_link_rdev(struct mddev *mddev, struct md_rdev *rdev)
static inline void sysfs_unlink_rdev(struct mddev *mddev, struct md_rdev *rdev)
{
char nm[20];
- if (!test_bit(Replacement, &rdev->flags)) {
+ if (!test_bit(Replacement, &rdev->flags) && mddev->kobj.sd) {
sprintf(nm, "rd%d", rdev->raid_disk);
sysfs_remove_link(&mddev->kobj, nm);
}