src/patches/suse-2.6.27.39/patches.suse/quota-Allow-negative-usage-of-space-and-inodes.patch

   1 From: Jan Kara <jack@suse.cz>
   2 References: fate#302681
   3 Subject: [PATCH 14/28] quota: Allow negative usage of space and inodes
   4 Patch-mainline: 2.6.29?
   5
   6 For clustered filesystems, it can happen that space / inode usage goes
   7 negative temporarily (because some node is allocating another node
   8 is freeing and they are not completely in sync). So let quota code
   9 allow this and change qsize_t so a signed type so that we don't
  10 underflow the variables.
  11
  12 Signed-off-by: Jan Kara <jack@suse.cz>
  13 ---
  14  fs/dquot.c            |    6 ++++--
  15  include/linux/quota.h |    3 ++-
  16  2 files changed, 6 insertions(+), 3 deletions(-)
  17
  18 diff --git a/fs/dquot.c b/fs/dquot.c
  19 index 904bd67..f4258fe 100644
  20 --- a/fs/dquot.c
  21 +++ b/fs/dquot.c
  22 @@ -845,7 +845,8 @@ static inline void dquot_incr_space(struct dquot *dquot, qsize_t number)
  23
  24  static inline void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
  25  {
  26 -       if (dquot->dq_dqb.dqb_curinodes > number)
  27 +       if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
  28 +           dquot->dq_dqb.dqb_curinodes >= number)
  29                 dquot->dq_dqb.dqb_curinodes -= number;
  30         else
  31                 dquot->dq_dqb.dqb_curinodes = 0;
  32 @@ -856,7 +857,8 @@ static inline void dquot_decr_inodes(struct dquot *dquot, qsize_t number)
  33
  34  static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
  35  {
  36 -       if (dquot->dq_dqb.dqb_curspace > number)
  37 +       if (sb_dqopt(dquot->dq_sb)->flags & DQUOT_NEGATIVE_USAGE ||
  38 +           dquot->dq_dqb.dqb_curspace >= number)
  39                 dquot->dq_dqb.dqb_curspace -= number;
  40         else
  41                 dquot->dq_dqb.dqb_curspace = 0;
  42 diff --git a/include/linux/quota.h b/include/linux/quota.h
  43 index e05c30d..0ee2a55 100644
  44 --- a/include/linux/quota.h
  45 +++ b/include/linux/quota.h
  46 @@ -170,7 +170,7 @@ enum {
  47  #include <asm/atomic.h>
  48
  49  typedef __kernel_uid32_t qid_t; /* Type in which we store ids in memory */
  50 -typedef __u64 qsize_t;          /* Type in which we store sizes */
  51 +typedef __s64 qsize_t;          /* Type in which we store sizes */
  52
  53  extern spinlock_t dq_data_lock;
  54
  55 @@ -338,6 +338,7 @@ enum {
  56                                                  * responsible for setting
  57                                                  * S_NOQUOTA, S_NOATIME flags
  58                                                  */
  59 +#define DQUOT_NEGATIVE_USAGE   (1 << 7)        /* Allow negative quota usage */
  60
  61  static inline unsigned int dquot_state_flag(unsigned int flags, int type)
  62  {
  63 --
  64 1.5.2.4
  65