quota: Allow negative usage of space and inodes

For clustered filesystems, it can happen that space / inode usage goes
negative temporarily (because some node is allocating another node
is freeing and they are not completely in sync). So let quota code
allow this and change qsize_t so a signed type so that we don't
underflow the variables.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This commit is contained in:
Jan Kara 2008-10-01 18:21:39 +02:00 committed by Mark Fasheh
parent e3d4d56b97
commit db49d2df48
2 changed files with 6 additions and 3 deletions

View file

@ -847,7 +847,8 @@ static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
static inline void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
{
if (dquot->dq_dqb.dqb_curinodes > number)
if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
dquot->dq_dqb.dqb_curinodes >= number)
dquot->dq_dqb.dqb_curinodes -= number;
else
dquot->dq_dqb.dqb_curinodes = 0;
@ -858,7 +859,8 @@ static inline void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
{
if (dquot->dq_dqb.dqb_curspace > number)
if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
dquot->dq_dqb.dqb_curspace >= number)
dquot->dq_dqb.dqb_curspace -= number;
else
dquot->dq_dqb.dqb_curspace = 0;

View file

@ -168,7 +168,7 @@ enum {
#include <asm/atomic.h>
typedef __kernel_uid32_t qid_t; /* Type in which we store ids in memory */
typedef __u64 qsize_t; /* Type in which we store sizes */
typedef long long qsize_t; /* Type in which we store sizes */
extern spinlock_t dq_data_lock;
@ -336,6 +336,7 @@ enum {
* responsible for setting
* S_NOQUOTA, S_NOATIME flags
*/
#define DQUOT_NEGATIVE_USAGE (1 << 7) /* Allow negative quota usage */
static inline unsigned int dquot_state_flag(unsigned int flags, int type)
{