xfs: use a normal shrinker for the dquot freelist

Stop reusing dquots from the freelist when allocating new ones directly, and
implement a shrinker that actually follows the specifications for the
interface.  The shrinker implementation is still highly suboptimal at this
point, but we can gradually work on it.

This also fixes an bug in the previous lock ordering, where we would take
the hash and dqlist locks inside of the freelist lock against the normal
lock ordering.  This is only solvable by introducing the dispose list,
and thus not when using direct reclaim of unused dquots for new allocations.

As a side-effect the quota upper bound and used to free ratio values in
/proc/fs/xfs/xqm are set to 0 as these values don't make any sense in the
new world order.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

(cherry picked from commit 04da0c8196ac0b12fb6b84f4b7a51ad2fa56d869)

1 files changed, 0 insertions, 14 deletions

diff --git a/fs/xfs/xfs_qm.h b/fs/xfs/xfs_qm.h
index 9b4f3adefbc5..9a9b997e1a0a 100644
--- a/fs/xfs/xfs_qm.h
+++ b/fs/xfs/xfs_qm.h
@@ -26,24 +26,12 @@
 struct xfs_qm;
 struct xfs_inode;
 
-extern uint             ndquot;
 extern struct mutex     xfs_Gqm_lock;
 extern struct xfs_qm    *xfs_Gqm;
 extern kmem_zone_t      *qm_dqzone;
 extern kmem_zone_t      *qm_dqtrxzone;
 
 /*
- * Ditto, for xfs_qm_dqreclaim_one.
- */
-#define XFS_QM_RECLAIM_MAX_RESTARTS     4
-
-/*
- * Ideal ratio of free to in use dquots. Quota manager makes an attempt
- * to keep this balance.
- */
-#define XFS_QM_DQFREE_RATIO             2
-
-/*
  * Dquot hashtable constants/threshold values.
  */
 #define XFS_QM_HASHSIZE_LOW             (PAGE_SIZE / sizeof(xfs_dqhash_t))
@@ -74,7 +62,6 @@ typedef struct xfs_qm {
         int              qm_dqfrlist_cnt;
         atomic_t         qm_totaldquots; /* total incore dquots */
         uint             qm_nrefs;       /* file systems with quota on */
-        int              qm_dqfree_ratio;/* ratio of free to inuse dquots */
         kmem_zone_t     *qm_dqzone;      /* dquot mem-alloc zone */
         kmem_zone_t     *qm_dqtrxzone;   /* t_dqinfo of transactions */
 } xfs_qm_t;
@@ -143,7 +130,6 @@ extern int		xfs_qm_quotacheck(xfs_mount_t *);
 extern int              xfs_qm_write_sb_changes(xfs_mount_t *, __int64_t);
 
 /* dquot stuff */
-extern boolean_t        xfs_qm_dqalloc_incore(xfs_dquot_t **);
 extern int              xfs_qm_dqpurge_all(xfs_mount_t *, uint);
 extern void             xfs_qm_dqrele_all_inodes(xfs_mount_t *, uint);