Jan Kara
2008-Oct-20 17:23 UTC
[Ocfs2-devel] [PATCH] 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 at suse.cz> --- fs/dquot.c | 6 ++++-- include/linux/quota.h | 3 ++- 2 files changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/dquot.c b/fs/dquot.c index 904bd67..f4258fe 100644 --- a/fs/dquot.c +++ b/fs/dquot.c @@ -845,7 +845,8 @@ 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; @@ -856,7 +857,8 @@ 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; diff --git a/include/linux/quota.h b/include/linux/quota.h index 3dca22c..597e8e9 100644 --- a/include/linux/quota.h +++ b/include/linux/quota.h @@ -170,7 +170,7 @@ 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 __s64 qsize_t; /* Type in which we store sizes */ extern spinlock_t dq_data_lock; @@ -341,6 +341,7 @@ 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) { -- 1.5.2.4