]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - fs/gfs2/glock.c
[PATCH] m32r: build fix for processors without ISA_DSP_LEVEL2
[linux-2.6-omap-h63xx.git] / fs / gfs2 / glock.c
index 49512696160e0a2760f3f8bcd17211c6e3cf88a7..6618c1190252881f6aae8266d7303deec76398ae 100644 (file)
 #include <linux/delay.h>
 #include <linux/sort.h>
 #include <linux/jhash.h>
-#include <linux/kref.h>
 #include <linux/kallsyms.h>
 #include <linux/gfs2_ondisk.h>
+#include <linux/list.h>
+#include <linux/lm_interface.h>
+#include <linux/wait.h>
+#include <linux/rwsem.h>
 #include <asm/uaccess.h>
 
 #include "gfs2.h"
-#include "lm_interface.h"
 #include "incore.h"
 #include "glock.h"
 #include "glops.h"
 #include "super.h"
 #include "util.h"
 
-/*  Must be kept in sync with the beginning of struct gfs2_glock  */
-struct glock_plug {
-       struct list_head gl_list;
-       unsigned long gl_flags;
-};
-
-struct greedy {
-       struct gfs2_holder gr_gh;
-       struct work_struct gr_work;
-};
-
 struct gfs2_gl_hash_bucket {
-        struct list_head hb_list;
+        struct hlist_head hb_list;
 };
 
 typedef void (*glock_examiner) (struct gfs2_glock * gl);
 
 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp);
 static int dump_glock(struct gfs2_glock *gl);
+static int dump_inode(struct gfs2_inode *ip);
+static void gfs2_glock_xmote_th(struct gfs2_holder *gh);
+static void gfs2_glock_drop_th(struct gfs2_glock *gl);
+static DECLARE_RWSEM(gfs2_umount_flush_sem);
+
+#define GFS2_GL_HASH_SHIFT      15
+#define GFS2_GL_HASH_SIZE       (1 << GFS2_GL_HASH_SHIFT)
+#define GFS2_GL_HASH_MASK       (GFS2_GL_HASH_SIZE - 1)
 
 static struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE];
-static rwlock_t gl_hash_locks[GFS2_GL_HASH_SIZE];
+
+/*
+ * Despite what you might think, the numbers below are not arbitrary :-)
+ * They are taken from the ipv4 routing hash code, which is well tested
+ * and thus should be nearly optimal. Later on we might tweek the numbers
+ * but for now this should be fine.
+ *
+ * The reason for putting the locks in a separate array from the list heads
+ * is that we can have fewer locks than list heads and save memory. We use
+ * the same hash function for both, but with a different hash mask.
+ */
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
+       defined(CONFIG_PROVE_LOCKING)
+
+#ifdef CONFIG_LOCKDEP
+# define GL_HASH_LOCK_SZ        256
+#else
+# if NR_CPUS >= 32
+#  define GL_HASH_LOCK_SZ       4096
+# elif NR_CPUS >= 16
+#  define GL_HASH_LOCK_SZ       2048
+# elif NR_CPUS >= 8
+#  define GL_HASH_LOCK_SZ       1024
+# elif NR_CPUS >= 4
+#  define GL_HASH_LOCK_SZ       512
+# else
+#  define GL_HASH_LOCK_SZ       256
+# endif
+#endif
+
+/* We never want more locks than chains */
+#if GFS2_GL_HASH_SIZE < GL_HASH_LOCK_SZ
+# undef GL_HASH_LOCK_SZ
+# define GL_HASH_LOCK_SZ GFS2_GL_HASH_SIZE
+#endif
+
+static rwlock_t gl_hash_locks[GL_HASH_LOCK_SZ];
+
+static inline rwlock_t *gl_lock_addr(unsigned int x)
+{
+       return &gl_hash_locks[x & (GL_HASH_LOCK_SZ-1)];
+}
+#else /* not SMP, so no spinlocks required */
+static inline rwlock_t *gl_lock_addr(unsigned int x)
+{
+       return NULL;
+}
+#endif
 
 /**
  * relaxed_state_ok - is a requested lock compatible with the current lock mode?
@@ -132,23 +178,7 @@ static void glock_free(struct gfs2_glock *gl)
 
 void gfs2_glock_hold(struct gfs2_glock *gl)
 {
-       kref_get(&gl->gl_ref);
-}
-
-/* All work is done after the return from kref_put() so we
-   can release the write_lock before the free. */
-
-static void kill_glock(struct kref *kref)
-{
-       struct gfs2_glock *gl = container_of(kref, struct gfs2_glock, gl_ref);
-       struct gfs2_sbd *sdp = gl->gl_sbd;
-
-       gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED);
-       gfs2_assert(sdp, list_empty(&gl->gl_reclaim));
-       gfs2_assert(sdp, list_empty(&gl->gl_holders));
-       gfs2_assert(sdp, list_empty(&gl->gl_waiters1));
-       gfs2_assert(sdp, list_empty(&gl->gl_waiters2));
-       gfs2_assert(sdp, list_empty(&gl->gl_waiters3));
+       atomic_inc(&gl->gl_ref);
 }
 
 /**
@@ -160,45 +190,28 @@ static void kill_glock(struct kref *kref)
 int gfs2_glock_put(struct gfs2_glock *gl)
 {
        int rv = 0;
+       struct gfs2_sbd *sdp = gl->gl_sbd;
 
-       write_lock(&gl_hash_locks[gl->gl_hash]);
-       if (kref_put(&gl->gl_ref, kill_glock)) {
-               list_del_init(&gl_hash_table[gl->gl_hash].hb_list);
-               write_unlock(&gl_hash_locks[gl->gl_hash]);
+       write_lock(gl_lock_addr(gl->gl_hash));
+       if (atomic_dec_and_test(&gl->gl_ref)) {
+               hlist_del(&gl->gl_list);
+               write_unlock(gl_lock_addr(gl->gl_hash));
                BUG_ON(spin_is_locked(&gl->gl_spin));
+               gfs2_assert(sdp, gl->gl_state == LM_ST_UNLOCKED);
+               gfs2_assert(sdp, list_empty(&gl->gl_reclaim));
+               gfs2_assert(sdp, list_empty(&gl->gl_holders));
+               gfs2_assert(sdp, list_empty(&gl->gl_waiters1));
+               gfs2_assert(sdp, list_empty(&gl->gl_waiters2));
+               gfs2_assert(sdp, list_empty(&gl->gl_waiters3));
                glock_free(gl);
                rv = 1;
                goto out;
        }
-       write_unlock(&gl_hash_locks[gl->gl_hash]);
+       write_unlock(gl_lock_addr(gl->gl_hash));
 out:
        return rv;
 }
 
-/**
- * queue_empty - check to see if a glock's queue is empty
- * @gl: the glock
- * @head: the head of the queue to check
- *
- * This function protects the list in the event that a process already
- * has a holder on the list and is adding a second holder for itself.
- * The glmutex lock is what generally prevents processes from working
- * on the same glock at once, but the special case of adding a second
- * holder for yourself ("recursive" locking) doesn't involve locking
- * glmutex, making the spin lock necessary.
- *
- * Returns: 1 if the queue is empty
- */
-
-static inline int queue_empty(struct gfs2_glock *gl, struct list_head *head)
-{
-       int empty;
-       spin_lock(&gl->gl_spin);
-       empty = list_empty(head);
-       spin_unlock(&gl->gl_spin);
-       return empty;
-}
-
 /**
  * search_bucket() - Find struct gfs2_glock by lock number
  * @bucket: the bucket to search
@@ -212,16 +225,15 @@ static struct gfs2_glock *search_bucket(unsigned int hash,
                                        const struct lm_lockname *name)
 {
        struct gfs2_glock *gl;
+       struct hlist_node *h;
 
-       list_for_each_entry(gl, &gl_hash_table[hash].hb_list, gl_list) {
-               if (test_bit(GLF_PLUG, &gl->gl_flags))
-                       continue;
+       hlist_for_each_entry(gl, h, &gl_hash_table[hash].hb_list, gl_list) {
                if (!lm_name_equal(&gl->gl_name, name))
                        continue;
                if (gl->gl_sbd != sdp)
                        continue;
 
-               kref_get(&gl->gl_ref);
+               atomic_inc(&gl->gl_ref);
 
                return gl;
        }
@@ -243,9 +255,9 @@ static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp,
        unsigned int hash = gl_hash(sdp, name);
        struct gfs2_glock *gl;
 
-       read_lock(&gl_hash_locks[hash]);
+       read_lock(gl_lock_addr(hash));
        gl = search_bucket(hash, sdp, name);
-       read_unlock(&gl_hash_locks[hash]);
+       read_unlock(gl_lock_addr(hash));
 
        return gl;
 }
@@ -272,9 +284,9 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
        unsigned int hash = gl_hash(sdp, &name);
        int error;
 
-       read_lock(&gl_hash_locks[hash]);
+       read_lock(gl_lock_addr(hash));
        gl = search_bucket(hash, sdp, &name);
-       read_unlock(&gl_hash_locks[hash]);
+       read_unlock(gl_lock_addr(hash));
 
        if (gl || !create) {
                *glp = gl;
@@ -287,7 +299,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
 
        gl->gl_flags = 0;
        gl->gl_name = name;
-       kref_init(&gl->gl_ref);
+       atomic_set(&gl->gl_ref, 1);
        gl->gl_state = LM_ST_UNLOCKED;
        gl->gl_hash = hash;
        gl->gl_owner = NULL;
@@ -316,15 +328,15 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
        if (error)
                goto fail_aspace;
 
-       write_lock(&gl_hash_locks[hash]);
+       write_lock(gl_lock_addr(hash));
        tmp = search_bucket(hash, sdp, &name);
        if (tmp) {
-               write_unlock(&gl_hash_locks[hash]);
+               write_unlock(gl_lock_addr(hash));
                glock_free(gl);
                gl = tmp;
        } else {
-               list_add_tail(&gl->gl_list, &gl_hash_table[hash].hb_list);
-               write_unlock(&gl_hash_locks[hash]);
+               hlist_add_head(&gl->gl_list, &gl_hash_table[hash].hb_list);
+               write_unlock(gl_lock_addr(hash));
        }
 
        *glp = gl;
@@ -335,7 +347,7 @@ fail_aspace:
        if (gl->gl_aspace)
                gfs2_aspace_put(gl->gl_aspace);
 fail:
-       kmem_cache_free(gfs2_glock_cachep, gl); 
+       kmem_cache_free(gfs2_glock_cachep, gl);
        return error;
 }
 
@@ -359,11 +371,6 @@ void gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, unsigned flags,
        gh->gh_flags = flags;
        gh->gh_error = 0;
        gh->gh_iflags = 0;
-       init_completion(&gh->gh_wait);
-
-       if (gh->gh_state == LM_ST_EXCLUSIVE)
-               gh->gh_flags |= GL_LOCAL_EXCL;
-
        gfs2_glock_hold(gl);
 }
 
@@ -381,9 +388,6 @@ void gfs2_holder_reinit(unsigned int state, unsigned flags, struct gfs2_holder *
 {
        gh->gh_state = state;
        gh->gh_flags = flags;
-       if (gh->gh_state == LM_ST_EXCLUSIVE)
-               gh->gh_flags |= GL_LOCAL_EXCL;
-
        gh->gh_iflags &= 1 << HIF_ALLOCED;
        gh->gh_ip = (unsigned long)__builtin_return_address(0);
 }
@@ -443,6 +447,29 @@ static void gfs2_holder_put(struct gfs2_holder *gh)
        kfree(gh);
 }
 
+static void gfs2_holder_dispose_or_wake(struct gfs2_holder *gh)
+{
+       if (test_bit(HIF_DEALLOC, &gh->gh_iflags)) {
+               gfs2_holder_put(gh);
+               return;
+       }
+       clear_bit(HIF_WAIT, &gh->gh_iflags);
+       smp_mb();
+       wake_up_bit(&gh->gh_iflags, HIF_WAIT);
+}
+
+static int holder_wait(void *word)
+{
+        schedule();
+        return 0;
+}
+
+static void wait_on_holder(struct gfs2_holder *gh)
+{
+       might_sleep();
+       wait_on_bit(&gh->gh_iflags, HIF_WAIT, holder_wait, TASK_UNINTERRUPTIBLE);
+}
+
 /**
  * rq_mutex - process a mutex request in the queue
  * @gh: the glock holder
@@ -457,7 +484,9 @@ static int rq_mutex(struct gfs2_holder *gh)
        list_del_init(&gh->gh_list);
        /*  gh->gh_error never examined.  */
        set_bit(GLF_LOCK, &gl->gl_flags);
-       complete(&gh->gh_wait);
+       clear_bit(HIF_WAIT, &gh->gh_iflags);
+       smp_mb();
+       wake_up_bit(&gh->gh_iflags, HIF_WAIT);
 
        return 1;
 }
@@ -475,7 +504,6 @@ static int rq_promote(struct gfs2_holder *gh)
 {
        struct gfs2_glock *gl = gh->gh_gl;
        struct gfs2_sbd *sdp = gl->gl_sbd;
-       const struct gfs2_glock_operations *glops = gl->gl_ops;
 
        if (!relaxed_state_ok(gl->gl_state, gh->gh_state, gh->gh_flags)) {
                if (list_empty(&gl->gl_holders)) {
@@ -490,7 +518,7 @@ static int rq_promote(struct gfs2_holder *gh)
                                gfs2_reclaim_glock(sdp);
                        }
 
-                       glops->go_xmote_th(gl, gh->gh_state, gh->gh_flags);
+                       gfs2_glock_xmote_th(gh);
                        spin_lock(&gl->gl_spin);
                }
                return 1;
@@ -501,11 +529,11 @@ static int rq_promote(struct gfs2_holder *gh)
                set_bit(GLF_LOCK, &gl->gl_flags);
        } else {
                struct gfs2_holder *next_gh;
-               if (gh->gh_flags & GL_LOCAL_EXCL)
+               if (gh->gh_state == LM_ST_EXCLUSIVE)
                        return 1;
                next_gh = list_entry(gl->gl_holders.next, struct gfs2_holder,
                                     gh_list);
-               if (next_gh->gh_flags & GL_LOCAL_EXCL)
+               if (next_gh->gh_state == LM_ST_EXCLUSIVE)
                         return 1;
        }
 
@@ -513,7 +541,7 @@ static int rq_promote(struct gfs2_holder *gh)
        gh->gh_error = 0;
        set_bit(HIF_HOLDER, &gh->gh_iflags);
 
-       complete(&gh->gh_wait);
+       gfs2_holder_dispose_or_wake(gh);
 
        return 0;
 }
@@ -528,7 +556,6 @@ static int rq_promote(struct gfs2_holder *gh)
 static int rq_demote(struct gfs2_holder *gh)
 {
        struct gfs2_glock *gl = gh->gh_gl;
-       const struct gfs2_glock_operations *glops = gl->gl_ops;
 
        if (!list_empty(&gl->gl_holders))
                return 1;
@@ -537,10 +564,7 @@ static int rq_demote(struct gfs2_holder *gh)
                list_del_init(&gh->gh_list);
                gh->gh_error = 0;
                spin_unlock(&gl->gl_spin);
-               if (test_bit(HIF_DEALLOC, &gh->gh_iflags))
-                       gfs2_holder_put(gh);
-               else
-                       complete(&gh->gh_wait);
+               gfs2_holder_dispose_or_wake(gh);
                spin_lock(&gl->gl_spin);
        } else {
                gl->gl_req_gh = gh;
@@ -549,9 +573,9 @@ static int rq_demote(struct gfs2_holder *gh)
 
                if (gh->gh_state == LM_ST_UNLOCKED ||
                    gl->gl_state != LM_ST_EXCLUSIVE)
-                       glops->go_drop_th(gl);
+                       gfs2_glock_drop_th(gl);
                else
-                       glops->go_xmote_th(gl, gh->gh_state, gh->gh_flags);
+                       gfs2_glock_xmote_th(gh);
 
                spin_lock(&gl->gl_spin);
        }
@@ -559,30 +583,6 @@ static int rq_demote(struct gfs2_holder *gh)
        return 0;
 }
 
-/**
- * rq_greedy - process a queued request to drop greedy status
- * @gh: the glock holder
- *
- * Returns: 1 if the queue is blocked
- */
-
-static int rq_greedy(struct gfs2_holder *gh)
-{
-       struct gfs2_glock *gl = gh->gh_gl;
-
-       list_del_init(&gh->gh_list);
-       /*  gh->gh_error never examined.  */
-       clear_bit(GLF_GREEDY, &gl->gl_flags);
-       spin_unlock(&gl->gl_spin);
-
-       gfs2_holder_uninit(gh);
-       kfree(container_of(gh, struct greedy, gr_gh));
-
-       spin_lock(&gl->gl_spin);                
-
-       return 0;
-}
-
 /**
  * run_queue - process holder structures on a glock
  * @gl: the glock
@@ -613,8 +613,6 @@ static void run_queue(struct gfs2_glock *gl)
 
                        if (test_bit(HIF_DEMOTE, &gh->gh_iflags))
                                blocked = rq_demote(gh);
-                       else if (test_bit(HIF_GREEDY, &gh->gh_iflags))
-                               blocked = rq_greedy(gh);
                        else
                                gfs2_assert_warn(gl->gl_sbd, 0);
 
@@ -648,6 +646,8 @@ static void gfs2_glmutex_lock(struct gfs2_glock *gl)
 
        gfs2_holder_init(gl, 0, 0, &gh);
        set_bit(HIF_MUTEX, &gh.gh_iflags);
+       if (test_and_set_bit(HIF_WAIT, &gh.gh_iflags))
+               BUG();
 
        spin_lock(&gl->gl_spin);
        if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
@@ -655,11 +655,13 @@ static void gfs2_glmutex_lock(struct gfs2_glock *gl)
        } else {
                gl->gl_owner = current;
                gl->gl_ip = (unsigned long)__builtin_return_address(0);
-               complete(&gh.gh_wait);
+               clear_bit(HIF_WAIT, &gh.gh_iflags);
+               smp_mb();
+               wake_up_bit(&gh.gh_iflags, HIF_WAIT);
        }
        spin_unlock(&gl->gl_spin);
 
-       wait_for_completion(&gh.gh_wait);
+       wait_on_holder(&gh);
        gfs2_holder_uninit(&gh);
 }
 
@@ -733,11 +735,12 @@ restart:
        } else {
                spin_unlock(&gl->gl_spin);
 
-               new_gh = gfs2_holder_get(gl, state, LM_FLAG_TRY, GFP_KERNEL);
+               new_gh = gfs2_holder_get(gl, state, LM_FLAG_TRY, GFP_NOFS);
                if (!new_gh)
                        return;
                set_bit(HIF_DEMOTE, &new_gh->gh_iflags);
                set_bit(HIF_DEALLOC, &new_gh->gh_iflags);
+               set_bit(HIF_WAIT, &new_gh->gh_iflags);
 
                goto restart;
        }
@@ -749,21 +752,6 @@ out:
                gfs2_holder_put(new_gh);
 }
 
-void gfs2_glock_inode_squish(struct inode *inode)
-{
-       struct gfs2_holder gh;
-       struct gfs2_glock *gl = GFS2_I(inode)->i_gl;
-       gfs2_holder_init(gl, LM_ST_UNLOCKED, 0, &gh);
-       set_bit(HIF_DEMOTE, &gh.gh_iflags);
-       spin_lock(&gl->gl_spin);
-       gfs2_assert(inode->i_sb->s_fs_info, list_empty(&gl->gl_holders));
-       list_add_tail(&gh.gh_list, &gl->gl_waiters2);
-       run_queue(gl);
-       spin_unlock(&gl->gl_spin);
-       wait_for_completion(&gh.gh_wait);
-       gfs2_holder_uninit(&gh);
-}
-
 /**
  * state_change - record that the glock is now in a different state
  * @gl: the glock
@@ -804,19 +792,19 @@ static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
        int op_done = 1;
 
        gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
-       gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
+       gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
        gfs2_assert_warn(sdp, !(ret & LM_OUT_ASYNC));
 
        state_change(gl, ret & LM_OUT_ST_MASK);
 
        if (prev_state != LM_ST_UNLOCKED && !(ret & LM_OUT_CACHEABLE)) {
                if (glops->go_inval)
-                       glops->go_inval(gl, DIO_METADATA | DIO_DATA);
+                       glops->go_inval(gl, DIO_METADATA);
        } else if (gl->gl_state == LM_ST_DEFERRED) {
                /* We might not want to do this here.
                   Look at moving to the inode glops. */
                if (glops->go_inval)
-                       glops->go_inval(gl, DIO_DATA);
+                       glops->go_inval(gl, 0);
        }
 
        /*  Deal with each possible exit condition  */
@@ -887,12 +875,8 @@ static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
 
        gfs2_glock_put(gl);
 
-       if (gh) {
-               if (test_bit(HIF_DEALLOC, &gh->gh_iflags))
-                       gfs2_holder_put(gh);
-               else
-                       complete(&gh->gh_wait);
-       }
+       if (gh)
+               gfs2_holder_dispose_or_wake(gh);
 }
 
 /**
@@ -903,23 +887,26 @@ static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
  *
  */
 
-void gfs2_glock_xmote_th(struct gfs2_glock *gl, unsigned int state, int flags)
+void gfs2_glock_xmote_th(struct gfs2_holder *gh)
 {
+       struct gfs2_glock *gl = gh->gh_gl;
        struct gfs2_sbd *sdp = gl->gl_sbd;
+       int flags = gh->gh_flags;
+       unsigned state = gh->gh_state;
        const struct gfs2_glock_operations *glops = gl->gl_ops;
        int lck_flags = flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB |
                                 LM_FLAG_NOEXP | LM_FLAG_ANY |
                                 LM_FLAG_PRIORITY);
        unsigned int lck_ret;
 
+       if (glops->go_xmote_th)
+               glops->go_xmote_th(gl);
+
        gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
-       gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
+       gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
        gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED);
        gfs2_assert_warn(sdp, state != gl->gl_state);
 
-       if (gl->gl_state == LM_ST_EXCLUSIVE && glops->go_sync)
-               glops->go_sync(gl, DIO_METADATA | DIO_DATA | DIO_RELEASE);
-
        gfs2_glock_hold(gl);
        gl->gl_req_bh = xmote_bh;
 
@@ -950,16 +937,14 @@ static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
        const struct gfs2_glock_operations *glops = gl->gl_ops;
        struct gfs2_holder *gh = gl->gl_req_gh;
 
-       clear_bit(GLF_PREFETCH, &gl->gl_flags);
-
        gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
-       gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
+       gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
        gfs2_assert_warn(sdp, !ret);
 
        state_change(gl, LM_ST_UNLOCKED);
 
        if (glops->go_inval)
-               glops->go_inval(gl, DIO_METADATA | DIO_DATA);
+               glops->go_inval(gl, DIO_METADATA);
 
        if (gh) {
                spin_lock(&gl->gl_spin);
@@ -980,12 +965,8 @@ static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
 
        gfs2_glock_put(gl);
 
-       if (gh) {
-               if (test_bit(HIF_DEALLOC, &gh->gh_iflags))
-                       gfs2_holder_put(gh);
-               else
-                       complete(&gh->gh_wait);
-       }
+       if (gh)
+               gfs2_holder_dispose_or_wake(gh);
 }
 
 /**
@@ -994,19 +975,19 @@ static void drop_bh(struct gfs2_glock *gl, unsigned int ret)
  *
  */
 
-void gfs2_glock_drop_th(struct gfs2_glock *gl)
+static void gfs2_glock_drop_th(struct gfs2_glock *gl)
 {
        struct gfs2_sbd *sdp = gl->gl_sbd;
        const struct gfs2_glock_operations *glops = gl->gl_ops;
        unsigned int ret;
 
+       if (glops->go_drop_th)
+               glops->go_drop_th(gl);
+
        gfs2_assert_warn(sdp, test_bit(GLF_LOCK, &gl->gl_flags));
-       gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
+       gfs2_assert_warn(sdp, list_empty(&gl->gl_holders));
        gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED);
 
-       if (gl->gl_state == LM_ST_EXCLUSIVE && glops->go_sync)
-               glops->go_sync(gl, DIO_METADATA | DIO_DATA | DIO_RELEASE);
-
        gfs2_glock_hold(gl);
        gl->gl_req_bh = drop_bh;
 
@@ -1086,8 +1067,7 @@ static int glock_wait_internal(struct gfs2_holder *gh)
        if (gh->gh_flags & LM_FLAG_PRIORITY)
                do_cancels(gh);
 
-       wait_for_completion(&gh->gh_wait);
-
+       wait_on_holder(gh);
        if (gh->gh_error)
                return gh->gh_error;
 
@@ -1143,16 +1123,18 @@ static void add_to_queue(struct gfs2_holder *gh)
        struct gfs2_holder *existing;
 
        BUG_ON(!gh->gh_owner);
+       if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags))
+               BUG();
 
        existing = find_holder_by_owner(&gl->gl_holders, gh->gh_owner);
        if (existing) {
                print_symbol(KERN_WARNING "original: %s\n", existing->gh_ip);
                printk(KERN_INFO "pid : %d\n", existing->gh_owner->pid);
-               printk(KERN_INFO "lock type : %d lock state : %d\n", 
+               printk(KERN_INFO "lock type : %d lock state : %d\n",
                                existing->gh_gl->gl_name.ln_type, existing->gh_gl->gl_state);
                print_symbol(KERN_WARNING "new: %s\n", gh->gh_ip);
                printk(KERN_INFO "pid : %d\n", gh->gh_owner->pid);
-               printk(KERN_INFO "lock type : %d lock state : %d\n", 
+               printk(KERN_INFO "lock type : %d lock state : %d\n",
                                gl->gl_name.ln_type, gl->gl_state);
                BUG();
        }
@@ -1167,7 +1149,7 @@ static void add_to_queue(struct gfs2_holder *gh)
        if (gh->gh_flags & LM_FLAG_PRIORITY)
                list_add(&gh->gh_list, &gl->gl_waiters3);
        else
-               list_add_tail(&gh->gh_list, &gl->gl_waiters3);  
+               list_add_tail(&gh->gh_list, &gl->gl_waiters3);
 }
 
 /**
@@ -1206,11 +1188,6 @@ restart:
                }
        }
 
-       clear_bit(GLF_PREFETCH, &gl->gl_flags);
-
-       if (error == GLR_TRYFAILED && (gh->gh_flags & GL_DUMP))
-               dump_glock(gl);
-
        return error;
 }
 
@@ -1302,98 +1279,6 @@ void gfs2_glock_dq(struct gfs2_holder *gh)
        spin_unlock(&gl->gl_spin);
 }
 
-/**
- * gfs2_glock_prefetch - Try to prefetch a glock
- * @gl: the glock
- * @state: the state to prefetch in
- * @flags: flags passed to go_xmote_th()
- *
- */
-
-static void gfs2_glock_prefetch(struct gfs2_glock *gl, unsigned int state,
-                               int flags)
-{
-       const struct gfs2_glock_operations *glops = gl->gl_ops;
-
-       spin_lock(&gl->gl_spin);
-
-       if (test_bit(GLF_LOCK, &gl->gl_flags) || !list_empty(&gl->gl_holders) ||
-           !list_empty(&gl->gl_waiters1) || !list_empty(&gl->gl_waiters2) ||
-           !list_empty(&gl->gl_waiters3) ||
-           relaxed_state_ok(gl->gl_state, state, flags)) {
-               spin_unlock(&gl->gl_spin);
-               return;
-       }
-
-       set_bit(GLF_PREFETCH, &gl->gl_flags);
-       set_bit(GLF_LOCK, &gl->gl_flags);
-       spin_unlock(&gl->gl_spin);
-
-       glops->go_xmote_th(gl, state, flags);
-}
-
-static void greedy_work(void *data)
-{
-       struct greedy *gr = data;
-       struct gfs2_holder *gh = &gr->gr_gh;
-       struct gfs2_glock *gl = gh->gh_gl;
-       const struct gfs2_glock_operations *glops = gl->gl_ops;
-
-       clear_bit(GLF_SKIP_WAITERS2, &gl->gl_flags);
-
-       if (glops->go_greedy)
-               glops->go_greedy(gl);
-
-       spin_lock(&gl->gl_spin);
-
-       if (list_empty(&gl->gl_waiters2)) {
-               clear_bit(GLF_GREEDY, &gl->gl_flags);
-               spin_unlock(&gl->gl_spin);
-               gfs2_holder_uninit(gh);
-               kfree(gr);
-       } else {
-               gfs2_glock_hold(gl);
-               list_add_tail(&gh->gh_list, &gl->gl_waiters2);
-               run_queue(gl);
-               spin_unlock(&gl->gl_spin);
-               gfs2_glock_put(gl);
-       }
-}
-
-/**
- * gfs2_glock_be_greedy -
- * @gl:
- * @time:
- *
- * Returns: 0 if go_greedy will be called, 1 otherwise
- */
-
-int gfs2_glock_be_greedy(struct gfs2_glock *gl, unsigned int time)
-{
-       struct greedy *gr;
-       struct gfs2_holder *gh;
-
-       if (!time || gl->gl_sbd->sd_args.ar_localcaching ||
-           test_and_set_bit(GLF_GREEDY, &gl->gl_flags))
-               return 1;
-
-       gr = kmalloc(sizeof(struct greedy), GFP_KERNEL);
-       if (!gr) {
-               clear_bit(GLF_GREEDY, &gl->gl_flags);
-               return 1;
-       }
-       gh = &gr->gr_gh;
-
-       gfs2_holder_init(gl, 0, 0, gh);
-       set_bit(HIF_GREEDY, &gh->gh_iflags);
-       INIT_WORK(&gr->gr_work, greedy_work, gr);
-
-       set_bit(GLF_SKIP_WAITERS2, &gl->gl_flags);
-       schedule_delayed_work(&gr->gr_work, time);
-
-       return 0;
-}
-
 /**
  * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it
  * @gh: the holder structure
@@ -1443,26 +1328,17 @@ int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number,
 
 static int glock_compare(const void *arg_a, const void *arg_b)
 {
-       struct gfs2_holder *gh_a = *(struct gfs2_holder **)arg_a;
-       struct gfs2_holder *gh_b = *(struct gfs2_holder **)arg_b;
-       struct lm_lockname *a = &gh_a->gh_gl->gl_name;
-       struct lm_lockname *b = &gh_b->gh_gl->gl_name;
-       int ret = 0;
+       const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a;
+       const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b;
+       const struct lm_lockname *a = &gh_a->gh_gl->gl_name;
+       const struct lm_lockname *b = &gh_b->gh_gl->gl_name;
 
        if (a->ln_number > b->ln_number)
-               ret = 1;
-       else if (a->ln_number < b->ln_number)
-               ret = -1;
-       else {
-               if (gh_a->gh_state == LM_ST_SHARED &&
-                   gh_b->gh_state == LM_ST_EXCLUSIVE)
-                       ret = 1;
-               else if (!(gh_a->gh_flags & GL_LOCAL_EXCL) &&
-                        (gh_b->gh_flags & GL_LOCAL_EXCL))
-                       ret = 1;
-       }
-
-       return ret;
+               return 1;
+       if (a->ln_number < b->ln_number)
+               return -1;
+       BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type);
+       return 0;
 }
 
 /**
@@ -1605,34 +1481,6 @@ void gfs2_glock_dq_uninit_m(unsigned int num_gh, struct gfs2_holder *ghs)
                gfs2_glock_dq_uninit(&ghs[x]);
 }
 
-/**
- * gfs2_glock_prefetch_num - prefetch a glock based on lock number
- * @sdp: the filesystem
- * @number: the lock number
- * @glops: the glock operations for the type of glock
- * @state: the state to acquire the glock in
- * @flags: modifier flags for the aquisition
- *
- * Returns: errno
- */
-
-void gfs2_glock_prefetch_num(struct gfs2_sbd *sdp, u64 number,
-                            const struct gfs2_glock_operations *glops,
-                            unsigned int state, int flags)
-{
-       struct gfs2_glock *gl;
-       int error;
-
-       if (atomic_read(&sdp->sd_reclaim_count) <
-           gfs2_tune_get(sdp, gt_reclaim_limit)) {
-               error = gfs2_glock_get(sdp, number, glops, CREATE, &gl);
-               if (!error) {
-                       gfs2_glock_prefetch(gl, state, flags);
-                       gfs2_glock_put(gl);
-               }
-       }
-}
-
 /**
  * gfs2_lvb_hold - attach a LVB from a glock
  * @gl: The glock in question
@@ -1691,8 +1539,6 @@ static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
        if (!gl)
                return;
 
-       if (gl->gl_ops->go_callback)
-               gl->gl_ops->go_callback(gl, state);
        handle_callback(gl, state);
 
        spin_lock(&gl->gl_spin);
@@ -1734,12 +1580,14 @@ void gfs2_glock_cb(void *cb_data, unsigned int type, void *data)
                struct lm_async_cb *async = data;
                struct gfs2_glock *gl;
 
+               down_read(&gfs2_umount_flush_sem);
                gl = gfs2_glock_find(sdp, &async->lc_name);
                if (gfs2_assert_warn(sdp, gl))
                        return;
                if (!gfs2_assert_warn(sdp, gl->gl_req_bh))
                        gl->gl_req_bh(gl, async->lc_ret);
                gfs2_glock_put(gl);
+               up_read(&gfs2_umount_flush_sem);
                return;
        }
 
@@ -1760,22 +1608,6 @@ void gfs2_glock_cb(void *cb_data, unsigned int type, void *data)
        }
 }
 
-/**
- * gfs2_iopen_go_callback - Try to kick the inode/vnode associated with an
- *                          iopen glock from memory
- * @io_gl: the iopen glock
- * @state: the state into which the glock should be put
- *
- */
-
-void gfs2_iopen_go_callback(struct gfs2_glock *io_gl, unsigned int state)
-{
-
-       if (state != LM_ST_UNLOCKED)
-               return;
-       /* FIXME: remove this? */
-}
-
 /**
  * demote_ok - Check to see if it's ok to unlock a glock
  * @gl: the glock
@@ -1785,15 +1617,11 @@ void gfs2_iopen_go_callback(struct gfs2_glock *io_gl, unsigned int state)
 
 static int demote_ok(struct gfs2_glock *gl)
 {
-       struct gfs2_sbd *sdp = gl->gl_sbd;
        const struct gfs2_glock_operations *glops = gl->gl_ops;
        int demote = 1;
 
        if (test_bit(GLF_STICKY, &gl->gl_flags))
                demote = 0;
-       else if (test_bit(GLF_PREFETCH, &gl->gl_flags))
-               demote = time_after_eq(jiffies, gl->gl_stamp +
-                                   gfs2_tune_get(sdp, gt_prefetch_secs) * HZ);
        else if (glops->go_demote_ok)
                demote = glops->go_demote_ok(gl);
 
@@ -1849,7 +1677,7 @@ void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
        atomic_inc(&sdp->sd_reclaimed);
 
        if (gfs2_glmutex_trylock(gl)) {
-               if (queue_empty(gl, &gl->gl_holders) &&
+               if (list_empty(&gl->gl_holders) &&
                    gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
                        handle_callback(gl, LM_ST_UNLOCKED);
                gfs2_glmutex_unlock(gl);
@@ -1870,51 +1698,35 @@ void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
 static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
                          unsigned int hash)
 {
-       struct glock_plug plug;
-       struct list_head *tmp;
-       struct gfs2_glock *gl;
-       int entries;
-
-       /* Add "plug" to end of bucket list, work back up list from there */
-       memset(&plug.gl_flags, 0, sizeof(unsigned long));
-       set_bit(GLF_PLUG, &plug.gl_flags);
-
-       write_lock(&gl_hash_locks[hash]);
-       list_add(&plug.gl_list, &gl_hash_table[hash].hb_list);
-       write_unlock(&gl_hash_locks[hash]);
-
-       for (;;) {
-               write_lock(&gl_hash_locks[hash]);
-
-               for (;;) {
-                       tmp = plug.gl_list.next;
-
-                       if (tmp == &gl_hash_table[hash].hb_list) {
-                               list_del(&plug.gl_list);
-                               entries = !list_empty(&gl_hash_table[hash].hb_list);
-                               write_unlock(&gl_hash_locks[hash]);
-                               return entries;
-                       }
-                       gl = list_entry(tmp, struct gfs2_glock, gl_list);
-
-                       /* Move plug up list */
-                       list_move(&plug.gl_list, &gl->gl_list);
+       struct gfs2_glock *gl, *prev = NULL;
+       int has_entries = 0;
+       struct hlist_head *head = &gl_hash_table[hash].hb_list;
 
-                       if (test_bit(GLF_PLUG, &gl->gl_flags))
-                               continue;
-                       if (gl->gl_sbd != sdp)
-                               continue;
-
-                       /* examiner() must glock_put() */
+       read_lock(gl_lock_addr(hash));
+       /* Can't use hlist_for_each_entry - don't want prefetch here */
+       if (hlist_empty(head))
+               goto out;
+       gl = list_entry(head->first, struct gfs2_glock, gl_list);
+       while(1) {
+               if (gl->gl_sbd == sdp) {
                        gfs2_glock_hold(gl);
-
-                       break;
+                       read_unlock(gl_lock_addr(hash));
+                       if (prev)
+                               gfs2_glock_put(prev);
+                       prev = gl;
+                       examiner(gl);
+                       has_entries = 1;
+                       read_lock(gl_lock_addr(hash));
                }
-
-               write_unlock(&gl_hash_locks[hash]);
-
-               examiner(gl);
+               if (gl->gl_list.next == NULL)
+                       break;
+               gl = list_entry(gl->gl_list.next, struct gfs2_glock, gl_list);
        }
+out:
+       read_unlock(gl_lock_addr(hash));
+       if (prev)
+               gfs2_glock_put(prev);
+       return has_entries;
 }
 
 /**
@@ -1925,24 +1737,20 @@ static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
 
 static void scan_glock(struct gfs2_glock *gl)
 {
-       if (gl->gl_ops == &gfs2_inode_glops)
-               goto out;
+       if (gl->gl_ops == &gfs2_inode_glops && gl->gl_object)
+               return;
 
        if (gfs2_glmutex_trylock(gl)) {
-               if (queue_empty(gl, &gl->gl_holders) &&
-                   gl->gl_state != LM_ST_UNLOCKED &&
-                   demote_ok(gl))
+               if (list_empty(&gl->gl_holders) &&
+                   gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
                        goto out_schedule;
                gfs2_glmutex_unlock(gl);
        }
-out:
-       gfs2_glock_put(gl);
        return;
 
 out_schedule:
        gfs2_glmutex_unlock(gl);
        gfs2_glock_schedule_for_reclaim(gl);
-       gfs2_glock_put(gl);
 }
 
 /**
@@ -1955,10 +1763,8 @@ void gfs2_scand_internal(struct gfs2_sbd *sdp)
 {
        unsigned int x;
 
-       for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
+       for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
                examine_bucket(scan_glock, sdp, x);
-               cond_resched();
-       }
 }
 
 /**
@@ -1984,14 +1790,11 @@ static void clear_glock(struct gfs2_glock *gl)
        }
 
        if (gfs2_glmutex_trylock(gl)) {
-               if (queue_empty(gl, &gl->gl_holders) &&
+               if (list_empty(&gl->gl_holders) &&
                    gl->gl_state != LM_ST_UNLOCKED)
                        handle_callback(gl, LM_ST_UNLOCKED);
-
                gfs2_glmutex_unlock(gl);
        }
-
-       gfs2_glock_put(gl);
 }
 
 /**
@@ -2013,10 +1816,10 @@ void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait)
 
        for (;;) {
                cont = 0;
-
-               for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
+               for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
                        if (examine_bucket(clear_glock, sdp, x))
                                cont = 1;
+               }
 
                if (!wait || !cont)
                        break;
@@ -2029,7 +1832,9 @@ void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait)
                        t = jiffies;
                }
 
+               down_write(&gfs2_umount_flush_sem);
                invalidate_inodes(sdp->sd_vfs);
+               up_write(&gfs2_umount_flush_sem);
                msleep(10);
        }
 }
@@ -2089,7 +1894,7 @@ static int dump_inode(struct gfs2_inode *ip)
        printk(KERN_INFO "    num = %llu %llu\n",
                    (unsigned long long)ip->i_num.no_formal_ino,
                    (unsigned long long)ip->i_num.no_addr);
-       printk(KERN_INFO "    type = %u\n", IF2DT(ip->i_di.di_mode));
+       printk(KERN_INFO "    type = %u\n", IF2DT(ip->i_inode.i_mode));
        printk(KERN_INFO "    i_flags =");
        for (x = 0; x < 32; x++)
                if (test_bit(x, &ip->i_flags))
@@ -2125,7 +1930,7 @@ static int dump_glock(struct gfs2_glock *gl)
                        printk(" %u", x);
        }
        printk(" \n");
-       printk(KERN_INFO "  gl_ref = %d\n", atomic_read(&gl->gl_ref.refcount));
+       printk(KERN_INFO "  gl_ref = %d\n", atomic_read(&gl->gl_ref));
        printk(KERN_INFO "  gl_state = %u\n", gl->gl_state);
        printk(KERN_INFO "  gl_owner = %s\n", gl->gl_owner->comm);
        print_symbol(KERN_INFO "  gl_ip = %s\n", gl->gl_ip);
@@ -2199,16 +2004,15 @@ out:
 static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
 {
        struct gfs2_glock *gl;
+       struct hlist_node *h;
        unsigned int x;
        int error = 0;
 
        for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
 
-               read_lock(&gl_hash_locks[x]);
+               read_lock(gl_lock_addr(x));
 
-               list_for_each_entry(gl, &gl_hash_table[x].hb_list, gl_list) {
-                       if (test_bit(GLF_PLUG, &gl->gl_flags))
-                               continue;
+               hlist_for_each_entry(gl, h, &gl_hash_table[x].hb_list, gl_list) {
                        if (gl->gl_sbd != sdp)
                                continue;
 
@@ -2217,7 +2021,7 @@ static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
                                break;
                }
 
-               read_unlock(&gl_hash_locks[x]);
+               read_unlock(gl_lock_addr(x));
 
                if (error)
                        break;
@@ -2231,9 +2035,13 @@ int __init gfs2_glock_init(void)
 {
        unsigned i;
        for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
+               INIT_HLIST_HEAD(&gl_hash_table[i].hb_list);
+       }
+#ifdef GL_HASH_LOCK_SZ
+       for(i = 0; i < GL_HASH_LOCK_SZ; i++) {
                rwlock_init(&gl_hash_locks[i]);
-               INIT_LIST_HEAD(&gl_hash_table[i].hb_list);
        }
+#endif
        return 0;
 }