staging: lustre: obdclass: race lustre_profile_list

Running multiple mounts at the same time results in
lustre_profile_list corruption when adding a new profile.

This patch adds a new spin_lock to protect the list and
avoid the bug

Signed-off-by: Hiroya Nozaki <nozaki.hiroya@jp.fujitsu.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6600
Reviewed-on: http://review.whamcloud.com/14896
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Hiroya Nozaki 2016-10-27 18:11:55 -04:00 committed by Greg Kroah-Hartman
parent b44c295dba
commit f65053dff9
3 changed files with 54 additions and 8 deletions

View File

@ -176,10 +176,13 @@ struct lustre_profile {
char *lp_profile;
char *lp_dt;
char *lp_md;
int lp_refs;
bool lp_list_deleted;
};
struct lustre_profile *class_get_profile(const char *prof);
void class_del_profile(const char *prof);
void class_put_profile(struct lustre_profile *lprof);
void class_del_profiles(void);
#if LUSTRE_TRACKS_LOCK_EXP_REFS

View File

@ -929,6 +929,8 @@ int ll_fill_super(struct super_block *sb, struct vfsmount *mnt)
out_free:
kfree(md);
kfree(dt);
if (lprof)
class_put_profile(lprof);
if (err)
ll_put_super(sb);
else if (sbi->ll_flags & LL_SBI_VERBOSE)

View File

@ -585,16 +585,21 @@ static int class_del_conn(struct obd_device *obd, struct lustre_cfg *lcfg)
}
static LIST_HEAD(lustre_profile_list);
static DEFINE_SPINLOCK(lustre_profile_list_lock);
struct lustre_profile *class_get_profile(const char *prof)
{
struct lustre_profile *lprof;
spin_lock(&lustre_profile_list_lock);
list_for_each_entry(lprof, &lustre_profile_list, lp_list) {
if (!strcmp(lprof->lp_profile, prof)) {
lprof->lp_refs++;
spin_unlock(&lustre_profile_list_lock);
return lprof;
}
}
spin_unlock(&lustre_profile_list_lock);
return NULL;
}
EXPORT_SYMBOL(class_get_profile);
@ -639,7 +644,11 @@ static int class_add_profile(int proflen, char *prof, int osclen, char *osc,
}
}
spin_lock(&lustre_profile_list_lock);
lprof->lp_refs = 1;
lprof->lp_list_deleted = false;
list_add(&lprof->lp_list, &lustre_profile_list);
spin_unlock(&lustre_profile_list_lock);
return err;
free_lp_dt:
@ -659,27 +668,59 @@ void class_del_profile(const char *prof)
lprof = class_get_profile(prof);
if (lprof) {
spin_lock(&lustre_profile_list_lock);
/* because get profile increments the ref counter */
lprof->lp_refs--;
list_del(&lprof->lp_list);
kfree(lprof->lp_profile);
kfree(lprof->lp_dt);
kfree(lprof->lp_md);
kfree(lprof);
lprof->lp_list_deleted = true;
spin_unlock(&lustre_profile_list_lock);
class_put_profile(lprof);
}
}
EXPORT_SYMBOL(class_del_profile);
void class_put_profile(struct lustre_profile *lprof)
{
spin_lock(&lustre_profile_list_lock);
if (--lprof->lp_refs > 0) {
LASSERT(lprof->lp_refs > 0);
spin_unlock(&lustre_profile_list_lock);
return;
}
spin_unlock(&lustre_profile_list_lock);
/* confirm not a negative number */
LASSERT(!lprof->lp_refs);
/*
* At least one class_del_profile/profiles must be called
* on the target profile or lustre_profile_list will corrupt
*/
LASSERT(lprof->lp_list_deleted);
kfree(lprof->lp_profile);
kfree(lprof->lp_dt);
kfree(lprof->lp_md);
kfree(lprof);
}
EXPORT_SYMBOL(class_put_profile);
/* COMPAT_146 */
void class_del_profiles(void)
{
struct lustre_profile *lprof, *n;
spin_lock(&lustre_profile_list_lock);
list_for_each_entry_safe(lprof, n, &lustre_profile_list, lp_list) {
list_del(&lprof->lp_list);
kfree(lprof->lp_profile);
kfree(lprof->lp_dt);
kfree(lprof->lp_md);
kfree(lprof);
lprof->lp_list_deleted = true;
spin_unlock(&lustre_profile_list_lock);
class_put_profile(lprof);
spin_lock(&lustre_profile_list_lock);
}
spin_unlock(&lustre_profile_list_lock);
}
EXPORT_SYMBOL(class_del_profiles);