xfs: remove the global xfs_Gqm structure

If we initialize the slab caches for the quota code when XFS is loaded there
is no need for a global and reference counted quota manager structure.  Drop
all this overhead and also fix the error handling during quota initialization.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

7 files changed, 46 insertions, 174 deletions

diff --git a/fs/xfs/xfs_dquot.c b/fs/xfs/xfs_dquot.c
index 2896ac953ed6..4be16a0cbe5a 100644
--- a/fs/xfs/xfs_dquot.c
+++ b/fs/xfs/xfs_dquot.c
@@ -59,6 +59,9 @@ int xfs_dqreq_num;
 int xfs_dqerror_mod = 33;
 #endif
 
+struct kmem_zone                *xfs_qm_dqtrxzone;
+static struct kmem_zone         *xfs_qm_dqzone;
+
 static struct lock_class_key xfs_dquot_other_class;
 
 /*
@@ -71,7 +74,7 @@ xfs_qm_dqdestroy(
         ASSERT(list_empty(&dqp->q_lru));
 
         mutex_destroy(&dqp->q_qlock);
-        kmem_zone_free(xfs_Gqm->qm_dqzone, dqp);
+        kmem_zone_free(xfs_qm_dqzone, dqp);
 
         XFS_STATS_DEC(xs_qm_dquot);
 }
@@ -491,7 +494,7 @@ xfs_qm_dqread(
         int                     cancelflags = 0;
 
 
-        dqp = kmem_zone_zalloc(xfs_Gqm->qm_dqzone, KM_SLEEP);
+        dqp = kmem_zone_zalloc(xfs_qm_dqzone, KM_SLEEP);
 
         dqp->dq_flags = type;
         dqp->q_core.d_id = cpu_to_be32(id);
@@ -1040,3 +1043,31 @@ xfs_dqflock_pushbuf_wait(
 out_lock:
         xfs_dqflock(dqp);
 }
+
+int __init
+xfs_qm_init(void)
+{
+        xfs_qm_dqzone =
+                kmem_zone_init(sizeof(struct xfs_dquot), "xfs_dquot");
+        if (!xfs_qm_dqzone)
+                goto out;
+
+        xfs_qm_dqtrxzone =
+                kmem_zone_init(sizeof(struct xfs_dquot_acct), "xfs_dqtrx");
+        if (!xfs_qm_dqtrxzone)
+                goto out_free_dqzone;
+
+        return 0;
+
+out_free_dqzone:
+        kmem_zone_destroy(xfs_qm_dqzone);
+out:
+        return -ENOMEM;
+}
+
+void __exit
+xfs_qm_exit(void)
+{
+        kmem_zone_destroy(xfs_qm_dqtrxzone);
+        kmem_zone_destroy(xfs_qm_dqzone);
+}
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 2f92d3b0d8a8..55c6afedc879 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -48,127 +48,11 @@
  * quota functionality, including maintaining the freelist and hash
  * tables of dquots.
  */
-struct mutex    xfs_Gqm_lock;
-struct xfs_qm   *xfs_Gqm;
-
-kmem_zone_t     *qm_dqzone;
-kmem_zone_t     *qm_dqtrxzone;
-
 STATIC int      xfs_qm_init_quotainos(xfs_mount_t *);
 STATIC int      xfs_qm_init_quotainfo(xfs_mount_t *);
 STATIC int      xfs_qm_shake(struct shrinker *, struct shrink_control *);
 
 /*
- * Initialize the XQM structure.
- * Note that there is not one quota manager per file system.
- */
-STATIC struct xfs_qm *
-xfs_Gqm_init(void)
-{
-        xfs_qm_t        *xqm;
-
-        xqm = kmem_zalloc(sizeof(xfs_qm_t), KM_SLEEP);
-
-        /*
-         * dquot zone. we register our own low-memory callback.
-         */
-        if (!qm_dqzone) {
-                xqm->qm_dqzone = kmem_zone_init(sizeof(xfs_dquot_t),
-                                                "xfs_dquots");
-                qm_dqzone = xqm->qm_dqzone;
-        } else
-                xqm->qm_dqzone = qm_dqzone;
-
-        /*
-         * The t_dqinfo portion of transactions.
-         */
-        if (!qm_dqtrxzone) {
-                xqm->qm_dqtrxzone = kmem_zone_init(sizeof(xfs_dquot_acct_t),
-                                                   "xfs_dqtrx");
-                qm_dqtrxzone = xqm->qm_dqtrxzone;
-        } else
-                xqm->qm_dqtrxzone = qm_dqtrxzone;
-
-        xqm->qm_nrefs = 0;
-        return xqm;
-}
-
-/*
- * Destroy the global quota manager when its reference count goes to zero.
- */
-STATIC void
-xfs_qm_destroy(
-        struct xfs_qm   *xqm)
-{
-        ASSERT(xqm != NULL);
-        ASSERT(xqm->qm_nrefs == 0);
-
-        kmem_free(xqm);
-}
-
-/*
- * Called at mount time to let XQM know that another file system is
- * starting quotas. This isn't crucial information as the individual mount
- * structures are pretty independent, but it helps the XQM keep a
- * global view of what's going on.
- */
-/* ARGSUSED */
-STATIC int
-xfs_qm_hold_quotafs_ref(
-        struct xfs_mount *mp)
-{
-        /*
-         * Need to lock the xfs_Gqm structure for things like this. For example,
-         * the structure could disappear between the entry to this routine and
-         * a HOLD operation if not locked.
-         */
-        mutex_lock(&xfs_Gqm_lock);
-
-        if (!xfs_Gqm) {
-                xfs_Gqm = xfs_Gqm_init();
-                if (!xfs_Gqm) {
-                        mutex_unlock(&xfs_Gqm_lock);
-                        return ENOMEM;
-                }
-        }
-
-        /*
-         * We can keep a list of all filesystems with quotas mounted for
-         * debugging and statistical purposes, but ...
-         * Just take a reference and get out.
-         */
-        xfs_Gqm->qm_nrefs++;
-        mutex_unlock(&xfs_Gqm_lock);
-
-        return 0;
-}
-
-
-/*
- * Release the reference that a filesystem took at mount time,
- * so that we know when we need to destroy the entire quota manager.
- */
-/* ARGSUSED */
-STATIC void
-xfs_qm_rele_quotafs_ref(
-        struct xfs_mount *mp)
-{
-        ASSERT(xfs_Gqm);
-        ASSERT(xfs_Gqm->qm_nrefs > 0);
-
-        /*
-         * Destroy the entire XQM. If somebody mounts with quotaon, this'll
-         * be restarted.
-         */
-        mutex_lock(&xfs_Gqm_lock);
-        if (--xfs_Gqm->qm_nrefs == 0) {
-                xfs_qm_destroy(xfs_Gqm);
-                xfs_Gqm = NULL;
-        }
-        mutex_unlock(&xfs_Gqm_lock);
-}
-
-/*
  * We use the batch lookup interface to iterate over the dquots as it
  * currently is the only interface into the radix tree code that allows
  * fuzzy lookups instead of exact matches.  Holding the lock over multiple
@@ -738,13 +622,6 @@ xfs_qm_init_quotainfo(
 
         ASSERT(XFS_IS_QUOTA_RUNNING(mp));
 
-        /*
-         * Tell XQM that we exist as soon as possible.
-         */
-        if ((error = xfs_qm_hold_quotafs_ref(mp))) {
-                return error;
-        }
-
         qinf = mp->m_quotainfo = kmem_zalloc(sizeof(xfs_quotainfo_t), KM_SLEEP);
 
         /*
@@ -850,17 +727,9 @@ xfs_qm_destroy_quotainfo(
 
         qi = mp->m_quotainfo;
         ASSERT(qi != NULL);
-        ASSERT(xfs_Gqm != NULL);
 
         unregister_shrinker(&qi->qi_shrinker);
 
-        /*
-         * Release the reference that XQM kept, so that we know
-         * when the XQM structure should be freed. We cannot assume
-         * that xfs_Gqm is non-null after this point.
-         */
-        xfs_qm_rele_quotafs_ref(mp);
-
         if (qi->qi_uquotaip) {
                 IRELE(qi->qi_uquotaip);
                 qi->qi_uquotaip = NULL; /* paranoia */
@@ -1447,7 +1316,6 @@ xfs_qm_quotacheck(
                  * We must turn off quotas.
                  */
                 ASSERT(mp->m_quotainfo != NULL);
-                ASSERT(xfs_Gqm != NULL);
                 xfs_qm_destroy_quotainfo(mp);
                 if (xfs_mount_reset_sbqflags(mp)) {
                         xfs_warn(mp,
diff --git a/fs/xfs/xfs_qm.h b/fs/xfs/xfs_qm.h
index 76447060cd47..44b858b79d71 100644
--- a/fs/xfs/xfs_qm.h
+++ b/fs/xfs/xfs_qm.h
@@ -22,13 +22,9 @@
 #include "xfs_dquot.h"
 #include "xfs_quota_priv.h"
 
-struct xfs_qm;
 struct xfs_inode;
 
-extern struct mutex     xfs_Gqm_lock;
-extern struct xfs_qm    *xfs_Gqm;
-extern kmem_zone_t      *qm_dqzone;
-extern kmem_zone_t      *qm_dqtrxzone;
+extern struct kmem_zone *xfs_qm_dqtrxzone;
 
 /*
  * This defines the unit of allocation of dquots.
@@ -42,15 +38,6 @@ extern kmem_zone_t	*qm_dqtrxzone;
 #define XFS_DQUOT_CLUSTER_SIZE_FSB      (xfs_filblks_t)1
 
 /*
- * Quota Manager (global) structure. Lives only in core.
- */
-typedef struct xfs_qm {
-        uint             qm_nrefs;       /* file systems with quota on */
-        kmem_zone_t     *qm_dqzone;      /* dquot mem-alloc zone */
-        kmem_zone_t     *qm_dqtrxzone;   /* t_dqinfo of transactions */
-} xfs_qm_t;
-
-/*
  * Various quota information for individual filesystems.
  * The mount structure keeps a pointer to this.
  */
diff --git a/fs/xfs/xfs_qm_bhv.c b/fs/xfs/xfs_qm_bhv.c
index 809f86857c6d..e6986b5d80d8 100644
--- a/fs/xfs/xfs_qm_bhv.c
+++ b/fs/xfs/xfs_qm_bhv.c
@@ -156,19 +156,3 @@ xfs_qm_newmount(
 
         return 0;
 }
-
-void __init
-xfs_qm_init(void)
-{
-        printk(KERN_INFO "SGI XFS Quota Management subsystem\n");
-        mutex_init(&xfs_Gqm_lock);
-}
-
-void __exit
-xfs_qm_exit(void)
-{
-        if (qm_dqzone)
-                kmem_zone_destroy(qm_dqzone);
-        if (qm_dqtrxzone)
-                kmem_zone_destroy(qm_dqtrxzone);
-}
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index e9ad7894648e..06d23b976f4c 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1654,13 +1654,17 @@ init_xfs_fs(void)
         if (error)
                 goto out_cleanup_procfs;
 
-        vfs_initquota();
+        error = xfs_qm_init();
+        if (error)
+                goto out_sysctl_unregister;
 
         error = register_filesystem(&xfs_fs_type);
         if (error)
-                goto out_sysctl_unregister;
+                goto out_qm_exit;
         return 0;
 
+ out_qm_exit:
+        xfs_qm_exit();
  out_sysctl_unregister:
         xfs_sysctl_unregister();
  out_cleanup_procfs:
@@ -1682,7 +1686,7 @@ init_xfs_fs(void)
 STATIC void __exit
 exit_xfs_fs(void)
 {
-        vfs_exitquota();
+        xfs_qm_exit();
         unregister_filesystem(&xfs_fs_type);
         xfs_sysctl_unregister();
         xfs_cleanup_procfs();
diff --git a/fs/xfs/xfs_super.h b/fs/xfs/xfs_super.h
index 50a3266c999e..09b0c26b2245 100644
--- a/fs/xfs/xfs_super.h
+++ b/fs/xfs/xfs_super.h
@@ -21,13 +21,11 @@
 #include <linux/exportfs.h>
 
 #ifdef CONFIG_XFS_QUOTA
-extern void xfs_qm_init(void);
+extern int xfs_qm_init(void);
 extern void xfs_qm_exit(void);
-# define vfs_initquota()        xfs_qm_init()
-# define vfs_exitquota()        xfs_qm_exit()
 #else
-# define vfs_initquota()        do { } while (0)
-# define vfs_exitquota()        do { } while (0)
+# define xfs_qm_init()  (0)
+# define xfs_qm_exit()  do { } while (0)
 #endif
 
 #ifdef CONFIG_XFS_POSIX_ACL
diff --git a/fs/xfs/xfs_trans_dquot.c b/fs/xfs/xfs_trans_dquot.c
index 877fe6367d2d..279099717ed2 100644
--- a/fs/xfs/xfs_trans_dquot.c
+++ b/fs/xfs/xfs_trans_dquot.c
@@ -875,7 +875,7 @@ STATIC void
 xfs_trans_alloc_dqinfo(
         xfs_trans_t     *tp)
 {
-        tp->t_dqinfo = kmem_zone_zalloc(xfs_Gqm->qm_dqtrxzone, KM_SLEEP);
+        tp->t_dqinfo = kmem_zone_zalloc(xfs_qm_dqtrxzone, KM_SLEEP);
 }
 
 void
@@ -884,6 +884,6 @@ xfs_trans_free_dqinfo(
 {
         if (!tp->t_dqinfo)
                 return;
-        kmem_zone_free(xfs_Gqm->qm_dqtrxzone, tp->t_dqinfo);
+        kmem_zone_free(xfs_qm_dqtrxzone, tp->t_dqinfo);
         tp->t_dqinfo = NULL;
 }