[GFS2] Move glock hash table out of superblock

There are several reasons why we want to do this:
 - Firstly its large and thus we'll scale better with multiple
   GFS2 fs mounted at the same time
 - Secondly its easier to scale its size as required (thats a plan
   for later patches)
 - Thirdly, we can use kzalloc rather than vmalloc when allocating
   the superblock (its now only 4888 bytes)
 - Fourth its all part of my plan to eventually be able to use RCU
   with the glock hash.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 34 insertions, 20 deletions

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 00769674f2ea..5759f52a1cf9 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -49,6 +49,8 @@ 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 struct gfs2_gl_hash_bucket gl_hash_table[GFS2_GL_HASH_SIZE];
+
 /**
  * relaxed_state_ok - is a requested lock compatible with the current lock mode?
  * @actual: the current state of the lock
@@ -231,10 +233,10 @@ static struct gfs2_glock *search_bucket(struct gfs2_gl_hash_bucket *bucket,
  * Returns: NULL, or the struct gfs2_glock with the requested number
  */
 
-static struct gfs2_glock *gfs2_glock_find(struct gfs2_sbd *sdp,
+static struct gfs2_glock *gfs2_glock_find(const struct gfs2_sbd *sdp,
                                           const struct lm_lockname *name)
 {
-        struct gfs2_gl_hash_bucket *bucket = &sdp->sd_gl_hash[gl_hash(sdp, name)];
+        struct gfs2_gl_hash_bucket *bucket = &gl_hash_table[gl_hash(sdp, name)];
         struct gfs2_glock *gl;
 
         read_lock(&bucket->hb_lock);
@@ -268,7 +270,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number,
 
         name.ln_number = number;
         name.ln_type = glops->go_type;
-        bucket = &sdp->sd_gl_hash[gl_hash(sdp, &name)];
+        bucket = &gl_hash_table[gl_hash(sdp, &name)];
 
         read_lock(&bucket->hb_lock);
         gl = search_bucket(bucket, sdp, &name);
@@ -648,9 +650,9 @@ static void gfs2_glmutex_lock(struct gfs2_glock *gl)
         set_bit(HIF_MUTEX, &gh.gh_iflags);
 
         spin_lock(&gl->gl_spin);
-        if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
+        if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
                 list_add_tail(&gh.gh_list, &gl->gl_waiters1);
-        else {
+        } else {
                 gl->gl_owner = current;
                 gl->gl_ip = (unsigned long)__builtin_return_address(0);
                 complete(&gh.gh_wait);
@@ -673,9 +675,9 @@ static int gfs2_glmutex_trylock(struct gfs2_glock *gl)
         int acquired = 1;
 
         spin_lock(&gl->gl_spin);
-        if (test_and_set_bit(GLF_LOCK, &gl->gl_flags))
+        if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) {
                 acquired = 0;
-        else {
+        } else {
                 gl->gl_owner = current;
                 gl->gl_ip = (unsigned long)__builtin_return_address(0);
         }
@@ -830,9 +832,9 @@ static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
                 spin_lock(&gl->gl_spin);
                 list_del_init(&gh->gh_list);
                 if (gl->gl_state == gh->gh_state ||
-                    gl->gl_state == LM_ST_UNLOCKED)
+                    gl->gl_state == LM_ST_UNLOCKED) {
                         gh->gh_error = 0;
-                else {
+                } else {
                         if (gfs2_assert_warn(sdp, gh->gh_flags &
                                         (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) == -1)
                                 fs_warn(sdp, "ret = 0x%.8X\n", ret);
@@ -1090,8 +1092,7 @@ static int glock_wait_internal(struct gfs2_holder *gh)
                 return gh->gh_error;
 
         gfs2_assert_withdraw(sdp, test_bit(HIF_HOLDER, &gh->gh_iflags));
-        gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state,
-                                                   gh->gh_state,
+        gfs2_assert_withdraw(sdp, relaxed_state_ok(gl->gl_state, gh->gh_state,
                                                    gh->gh_flags));
 
         if (test_bit(HIF_FIRST, &gh->gh_iflags)) {
@@ -1901,6 +1902,8 @@ static int examine_bucket(glock_examiner examiner, struct gfs2_sbd *sdp,
 
                         if (test_bit(GLF_PLUG, &gl->gl_flags))
                                 continue;
+                        if (gl->gl_sbd != sdp)
+                                continue;
 
                         /* examiner() must glock_put() */
                         gfs2_glock_hold(gl);
@@ -1953,7 +1956,7 @@ void gfs2_scand_internal(struct gfs2_sbd *sdp)
         unsigned int x;
 
         for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
-                examine_bucket(scan_glock, sdp, &sdp->sd_gl_hash[x]);
+                examine_bucket(scan_glock, sdp, &gl_hash_table[x]);
                 cond_resched();
         }
 }
@@ -2012,7 +2015,7 @@ void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait)
                 cont = 0;
 
                 for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
-                        if (examine_bucket(clear_glock, sdp, &sdp->sd_gl_hash[x]))
+                        if (examine_bucket(clear_glock, sdp, &gl_hash_table[x]))
                                 cont = 1;
 
                 if (!wait || !cont)
@@ -2114,14 +2117,13 @@ static int dump_glock(struct gfs2_glock *gl)
 
         spin_lock(&gl->gl_spin);
 
-        printk(KERN_INFO "Glock 0x%p (%u, %llu)\n",
-               gl,
-               gl->gl_name.ln_type,
+        printk(KERN_INFO "Glock 0x%p (%u, %llu)\n", gl, gl->gl_name.ln_type,
                (unsigned long long)gl->gl_name.ln_number);
         printk(KERN_INFO "  gl_flags =");
-        for (x = 0; x < 32; x++)
+        for (x = 0; x < 32; x++) {
                 if (test_bit(x, &gl->gl_flags))
                         printk(" %u", x);
+        }
         printk(" \n");
         printk(KERN_INFO "  gl_ref = %d\n", atomic_read(&gl->gl_ref.refcount));
         printk(KERN_INFO "  gl_state = %u\n", gl->gl_state);
@@ -2136,8 +2138,7 @@ static int dump_glock(struct gfs2_glock *gl)
         printk(KERN_INFO "  reclaim = %s\n",
                     (list_empty(&gl->gl_reclaim)) ? "no" : "yes");
         if (gl->gl_aspace)
-                printk(KERN_INFO "  aspace = 0x%p nrpages = %lu\n",
-                       gl->gl_aspace,
+                printk(KERN_INFO "  aspace = 0x%p nrpages = %lu\n", gl->gl_aspace,
                        gl->gl_aspace->i_mapping->nrpages);
         else
                 printk(KERN_INFO "  aspace = no\n");
@@ -2203,13 +2204,15 @@ static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
         int error = 0;
 
         for (x = 0; x < GFS2_GL_HASH_SIZE; x++) {
-                bucket = &sdp->sd_gl_hash[x];
+                bucket = &gl_hash_table[x];
 
                 read_lock(&bucket->hb_lock);
 
                 list_for_each_entry(gl, &bucket->hb_list, gl_list) {
                         if (test_bit(GLF_PLUG, &gl->gl_flags))
                                 continue;
+                        if (gl->gl_sbd != sdp)
+                                continue;
 
                         error = dump_glock(gl);
                         if (error)
@@ -2226,3 +2229,14 @@ static int gfs2_dump_lockstate(struct gfs2_sbd *sdp)
         return error;
 }
 
+int __init gfs2_glock_init(void)
+{
+        unsigned i;
+        for(i = 0; i < GFS2_GL_HASH_SIZE; i++) {
+                struct gfs2_gl_hash_bucket *hb = &gl_hash_table[i];
+                rwlock_init(&hb->hb_lock);
+                INIT_LIST_HEAD(&hb->hb_list);
+        }
+        return 0;
+}
+