3 files changed, 49 insertions, 54 deletions

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 17d474fab5ab..f82ecc0cc8fb 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -1814,7 +1814,7 @@ void gfs2_try_toss_inode(struct gfs2_sbd *sdp, struct gfs2_inum *inum)
         if (atomic_read(&ip->i_count))
                 goto out_unlock;
 
-        gfs2_inode_destroy(ip);
+        gfs2_inode_destroy(ip, 1);
 
  out_unlock:
         gfs2_glmutex_unlock(gl);
@@ -1940,7 +1940,7 @@ void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
                 if (gl->gl_ops == &gfs2_inode_glops) {
                         struct gfs2_inode *ip = gl->gl_object;
                         if (ip && !atomic_read(&ip->i_count))
-                                gfs2_inode_destroy(ip);
+                                gfs2_inode_destroy(ip, 1);
                 }
                 if (queue_empty(gl, &gl->gl_holders) &&
                     gl->gl_state != LM_ST_UNLOCKED &&
@@ -2083,7 +2083,7 @@ static void clear_glock(struct gfs2_glock *gl)
                 if (gl->gl_ops == &gfs2_inode_glops) {
                         struct gfs2_inode *ip = gl->gl_object;
                         if (ip && !atomic_read(&ip->i_count))
-                                gfs2_inode_destroy(ip);
+                                gfs2_inode_destroy(ip, 1);
                 }
                 if (queue_empty(gl, &gl->gl_holders) &&
                     gl->gl_state != LM_ST_UNLOCKED)
diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index fb5a4d06e926..9084d6037a0c 100644
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -287,7 +287,7 @@ int gfs2_inode_refresh(struct gfs2_inode *ip)
 
 static int inode_create(struct gfs2_glock *i_gl, const struct gfs2_inum *inum,
                         struct gfs2_glock *io_gl, unsigned int io_state,
-                        struct gfs2_inode **ipp)
+                        struct gfs2_inode **ipp, int need_lock)
 {
         struct gfs2_sbd *sdp = i_gl->gl_sbd;
         struct gfs2_inode *ip;
@@ -312,11 +312,13 @@ static int inode_create(struct gfs2_glock *i_gl, const struct gfs2_inum *inum,
 
         ip->i_greedy = gfs2_tune_get(sdp, gt_greedy_default);
 
-        error = gfs2_glock_nq_init(io_gl,
-                                   io_state, GL_LOCAL_EXCL | GL_EXACT,
-                                   &ip->i_iopen_gh);
-        if (error)
-                goto fail;
+        if (need_lock) {
+                error = gfs2_glock_nq_init(io_gl,
+                                           io_state, GL_LOCAL_EXCL | GL_EXACT,
+                                           &ip->i_iopen_gh);
+                if (error)
+                        goto fail;
+        }
         ip->i_iopen_gh.gh_owner = NULL;
 
         spin_lock(&io_gl->gl_spin);
@@ -376,7 +378,7 @@ int gfs2_inode_get(struct gfs2_glock *i_gl, const struct gfs2_inum *inum,
         error = gfs2_glock_get(sdp, inum->no_addr, &gfs2_iopen_glops,
                                CREATE, &io_gl);
         if (!error) {
-                error = inode_create(i_gl, inum, io_gl, LM_ST_SHARED, ipp);
+                error = inode_create(i_gl, inum, io_gl, LM_ST_SHARED, ipp, 1);
                 gfs2_glock_put(io_gl);
         }
 
@@ -398,21 +400,23 @@ void gfs2_inode_put(struct gfs2_inode *ip)
         atomic_dec(&ip->i_count);
 }
 
-void gfs2_inode_destroy(struct gfs2_inode *ip)
+void gfs2_inode_destroy(struct gfs2_inode *ip, int unlock)
 {
         struct gfs2_sbd *sdp = ip->i_sbd;
-        struct gfs2_glock *io_gl = ip->i_iopen_gh.gh_gl;
         struct gfs2_glock *i_gl = ip->i_gl;
 
         gfs2_assert_warn(sdp, !atomic_read(&ip->i_count));
-        gfs2_assert(sdp, io_gl->gl_object == i_gl);
-
-        spin_lock(&io_gl->gl_spin);
-        io_gl->gl_object = NULL;
-        spin_unlock(&io_gl->gl_spin);
-        gfs2_glock_put(i_gl);
-
-        gfs2_glock_dq_uninit(&ip->i_iopen_gh);
+        if (unlock) {
+                struct gfs2_glock *io_gl = ip->i_iopen_gh.gh_gl;
+                gfs2_assert(sdp, io_gl->gl_object == i_gl);
+        
+                spin_lock(&io_gl->gl_spin);
+                io_gl->gl_object = NULL;
+                spin_unlock(&io_gl->gl_spin);
+                gfs2_glock_put(i_gl);
+        
+                gfs2_glock_dq_uninit(&ip->i_iopen_gh);
+        }
 
         gfs2_meta_cache_flush(ip);
         kmem_cache_free(gfs2_inode_cachep, ip);
@@ -493,6 +497,13 @@ static int dinode_dealloc(struct gfs2_inode *ip, struct gfs2_unlinked *ul)
  * @inum: the inode number to deallocate
  * @io_gh: a holder for the iopen glock for this inode
  *
+ * N.B. When we enter this we already hold the iopen glock and getting
+ * the glock for the inode means that we are grabbing the locks in the
+ * "wrong" order so we must only so a try lock operation and fail if we
+ * don't get the lock. Thats ok, since if we fail it means someone else
+ * is using the inode still and thus we shouldn't be deallocating it
+ * anyway.
+ *
  * Returns: errno
  */
 
@@ -503,33 +514,21 @@ static int inode_dealloc(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul,
         struct gfs2_holder i_gh;
         int error;
 
-        error = gfs2_glock_nq_num(sdp,
-                                  ul->ul_ut.ut_inum.no_addr, &gfs2_inode_glops,
-                                  LM_ST_EXCLUSIVE, 0, &i_gh);
-        if (error)
-                return error;
-
-        /* We reacquire the iopen lock here to avoid a race with the NFS server
-           calling gfs2_read_inode() with the inode number of a inode we're in
-           the process of deallocating.  And we can't keep our hold on the lock
-           from inode_dealloc_init() for deadlock reasons. */
-
-        gfs2_holder_reinit(LM_ST_EXCLUSIVE, LM_FLAG_TRY, io_gh);
-        error = gfs2_glock_nq(io_gh);
-        switch (error) {
+        error = gfs2_glock_nq_num(sdp, ul->ul_ut.ut_inum.no_addr,
+                                  &gfs2_inode_glops, LM_ST_EXCLUSIVE,
+                                  LM_FLAG_TRY_1CB, &i_gh);
+        switch(error) {
         case 0:
                 break;
         case GLR_TRYFAILED:
-                error = 1;
+                return 1; /* or back off and relock in different order? */
         default:
-                goto out;
+                return error;
         }
 
         gfs2_assert_warn(sdp, !i_gh.gh_gl->gl_object);
         error = inode_create(i_gh.gh_gl, &ul->ul_ut.ut_inum, io_gh->gh_gl,
-                             LM_ST_EXCLUSIVE, &ip);
-
-        gfs2_glock_dq(io_gh);
+                             LM_ST_EXCLUSIVE, &ip, 0);
 
         if (error)
                 goto out;
@@ -568,13 +567,13 @@ static int inode_dealloc(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul,
         if (error)
                 goto out_iput;
 
- out_iput:
+out_iput:
         gfs2_glmutex_lock(i_gh.gh_gl);
         gfs2_inode_put(ip);
-        gfs2_inode_destroy(ip);
+        gfs2_inode_destroy(ip, 0);
         gfs2_glmutex_unlock(i_gh.gh_gl);
 
- out:
+out:
         gfs2_glock_dq_uninit(&i_gh);
 
         return error;
@@ -589,14 +588,13 @@ static int inode_dealloc(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul,
 
 static int try_inode_dealloc(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
 {
-        struct gfs2_holder io_gh;
         int error = 0;
+        struct gfs2_holder iogh;
 
         gfs2_try_toss_inode(sdp, &ul->ul_ut.ut_inum);
-
-        error = gfs2_glock_nq_num(sdp,
-                                  ul->ul_ut.ut_inum.no_addr, &gfs2_iopen_glops,
-                                  LM_ST_EXCLUSIVE, LM_FLAG_TRY_1CB, &io_gh);
+        error = gfs2_glock_nq_num(sdp, ul->ul_ut.ut_inum.no_addr,
+                                  &gfs2_iopen_glops, LM_ST_EXCLUSIVE,
+                                  LM_FLAG_TRY_1CB, &iogh);
         switch (error) {
         case 0:
                 break;
@@ -606,9 +604,8 @@ static int try_inode_dealloc(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
                 return error;
         }
 
-        gfs2_glock_dq(&io_gh);
-        error = inode_dealloc(sdp, ul, &io_gh);
-        gfs2_holder_uninit(&io_gh);
+        error = inode_dealloc(sdp, ul, &iogh);
+        gfs2_glock_dq_uninit(&iogh);
 
         return error;
 }
@@ -634,9 +631,7 @@ static int inode_dealloc_uninit(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul)
         if (error)
                 goto out;
 
-        error = gfs2_trans_begin(sdp,
-                                 RES_RG_BIT + RES_UNLINKED + RES_STATFS,
-                                 0);
+        error = gfs2_trans_begin(sdp, RES_RG_BIT + RES_UNLINKED + RES_STATFS, 0);
         if (error)
                 goto out_gunlock;
 
diff --git a/fs/gfs2/inode.h b/fs/gfs2/inode.h
index 0dd2a26626ec..13bc4eacac6b 100644
--- a/fs/gfs2/inode.h
+++ b/fs/gfs2/inode.h
@@ -39,7 +39,7 @@ int gfs2_inode_get(struct gfs2_glock *i_gl,
                    struct gfs2_inode **ipp);
 void gfs2_inode_hold(struct gfs2_inode *ip);
 void gfs2_inode_put(struct gfs2_inode *ip);
-void gfs2_inode_destroy(struct gfs2_inode *ip);
+void gfs2_inode_destroy(struct gfs2_inode *ip, int unlock);
 
 int gfs2_inode_dealloc(struct gfs2_sbd *sdp, struct gfs2_unlinked *ul);