Reorganize data elements to reduce struct sizes

Thanks for the comments. I have incorportated them all.

CONFIG_OCFS2_FS_STATS is enabled and CONFIG_DEBUG_LOCK_ALLOC is disabled.
Statistics now look like -
ocfs2_write_ctxt: 2144 - 2136 = 8
ocfs2_inode_info: 1960 - 1848 = 112
ocfs2_journal: 168 - 160 = 8
ocfs2_lock_res: 336 - 304 = 32
ocfs2_refcount_tree: 512 - 472 = 40

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.de>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

5 files changed, 24 insertions, 19 deletions

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 0de69c9a08b..f477f18b35d 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -883,8 +883,8 @@ struct ocfs2_write_ctxt {
          * out in so that future reads from that region will get
          * zero's.
          */
-        struct page                     *w_pages[OCFS2_MAX_CTXT_PAGES];
         unsigned int                    w_num_pages;
+        struct page                     *w_pages[OCFS2_MAX_CTXT_PAGES];
         struct page                     *w_target_page;
 
         /*
diff --git a/fs/ocfs2/inode.h b/fs/ocfs2/inode.h
index 6de5a869db3..0bc477a3aeb 100644
--- a/fs/ocfs2/inode.h
+++ b/fs/ocfs2/inode.h
@@ -46,27 +46,24 @@ struct ocfs2_inode_info
         /* These fields are protected by ip_lock */
         spinlock_t                      ip_lock;
         u32                             ip_open_count;
-        u32                             ip_clusters;
         struct list_head                ip_io_markers;
+        u32                             ip_clusters;
 
+        u16                             ip_dyn_features;
         struct mutex                    ip_io_mutex;
-
         u32                             ip_flags; /* see below */
         u32                             ip_attr; /* inode attributes */
-        u16                             ip_dyn_features;
 
         /* protected by recovery_lock. */
         struct inode                    *ip_next_orphan;
 
-        u32                             ip_dir_start_lookup;
-
         struct ocfs2_caching_info       ip_metadata_cache;
-
         struct ocfs2_extent_map         ip_extent_map;
-
         struct inode                    vfs_inode;
         struct jbd2_inode               ip_jinode;
 
+        u32                             ip_dir_start_lookup;
+
         /* Only valid if the inode is the dir. */
         u32                             ip_last_used_slot;
         u64                             ip_last_used_group;
diff --git a/fs/ocfs2/journal.h b/fs/ocfs2/journal.h
index b5baaa8e710..43e56b97f9c 100644
--- a/fs/ocfs2/journal.h
+++ b/fs/ocfs2/journal.h
@@ -67,11 +67,12 @@ struct ocfs2_journal {
         struct buffer_head        *j_bh;      /* Journal disk inode block */
         atomic_t                  j_num_trans; /* Number of transactions
                                                 * currently in the system. */
+        spinlock_t                j_lock;
         unsigned long             j_trans_id;
         struct rw_semaphore       j_trans_barrier;
         wait_queue_head_t         j_checkpointed;
 
-        spinlock_t                j_lock;
+        /* both fields protected by j_lock*/
         struct list_head          j_la_cleanups;
         struct work_struct        j_recovery_work;
 };
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index c67003b6b5a..65739b3b327 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -150,26 +150,33 @@ typedef void (*ocfs2_lock_callback)(int status, unsigned long data);
 struct ocfs2_lock_res {
         void                    *l_priv;
         struct ocfs2_lock_res_ops *l_ops;
-        spinlock_t               l_lock;
+
 
         struct list_head         l_blocked_list;
         struct list_head         l_mask_waiters;
 
-        enum ocfs2_lock_type     l_type;
         unsigned long            l_flags;
         char                     l_name[OCFS2_LOCK_ID_MAX_LEN];
-        int                      l_level;
         unsigned int             l_ro_holders;
         unsigned int             l_ex_holders;
-        struct ocfs2_dlm_lksb    l_lksb;
+        unsigned char            l_level;
+
+        /* Data packed - type enum ocfs2_lock_type */
+        unsigned char            l_type;
 
         /* used from AST/BAST funcs. */
-        enum ocfs2_ast_action    l_action;
-        enum ocfs2_unlock_action l_unlock_action;
-        int                      l_requested;
-        int                      l_blocking;
+        /* Data packed - enum type ocfs2_ast_action */
+        unsigned char            l_action;
+        /* Data packed - enum type ocfs2_unlock_action */
+        unsigned char            l_unlock_action;
+        unsigned char            l_requested;
+        unsigned char            l_blocking;
         unsigned int             l_pending_gen;
 
+        spinlock_t               l_lock;
+
+        struct ocfs2_dlm_lksb    l_lksb;
+
         wait_queue_head_t        l_event;
 
         struct list_head         l_debug_list;
diff --git a/fs/ocfs2/refcounttree.h b/fs/ocfs2/refcounttree.h
index 9983ba1570e..f04892d6175 100644
--- a/fs/ocfs2/refcounttree.h
+++ b/fs/ocfs2/refcounttree.h
@@ -21,14 +21,14 @@ struct ocfs2_refcount_tree {
         struct rb_node rf_node;
         u64 rf_blkno;
         u32 rf_generation;
+        struct kref rf_getcnt;
         struct rw_semaphore rf_sem;
         struct ocfs2_lock_res rf_lockres;
-        struct kref rf_getcnt;
         int rf_removed;
 
         /* the following 4 fields are used by caching_info. */
-        struct ocfs2_caching_info rf_ci;
         spinlock_t rf_lock;
+        struct ocfs2_caching_info rf_ci;
         struct mutex rf_io_mutex;
         struct super_block *rf_sb;
 };