ext4: ext4_inode_info diet

Generic inode has unused i_private pointer which may be used as cur_aio_dio
storage.

TODO: If cur_aio_dio will be passed as an argument to get_block_t this allow
      to have concurent AIO_DIO requests.

Reviewed-by: Zheng Liu <wenqing.lz@taobao.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

4 files changed, 15 insertions, 8 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 8b6902c4d7be..3e8e185e5e22 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -912,8 +912,6 @@ struct ext4_inode_info {
         struct list_head i_completed_io_list;
         spinlock_t i_completed_io_lock;
         atomic_t i_ioend_count; /* Number of outstanding io_end structs */
-        /* current io_end structure for async DIO write*/
-        ext4_io_end_t *cur_aio_dio;
         atomic_t i_aiodio_unwritten; /* Nr. of inflight conversions pending */
 
         spinlock_t i_block_reservation_lock;
@@ -1338,6 +1336,16 @@ static inline void ext4_set_io_unwritten_flag(struct inode *inode,
         }
 }
 
+static inline ext4_io_end_t *ext4_inode_aio(struct inode *inode)
+{
+        return inode->i_private;
+}
+
+static inline void ext4_inode_aio_set(struct inode *inode, ext4_io_end_t *io)
+{
+        inode->i_private = io;
+}
+
 /*
  * Inode dynamic state flags
  */
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 8f08c7b77179..a1f56c3e773b 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3618,7 +3618,7 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
 {
         int ret = 0;
         int err = 0;
-        ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
+        ext4_io_end_t *io = ext4_inode_aio(inode);
 
         ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical "
                   "block %llu, max_blocks %u, flags %x, allocated %u\n",
@@ -3876,7 +3876,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
         unsigned int allocated = 0, offset = 0;
         unsigned int allocated_clusters = 0;
         struct ext4_allocation_request ar;
-        ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
+        ext4_io_end_t *io = ext4_inode_aio(inode);
         ext4_lblk_t cluster_offset;
 
         ext_debug("blocks %u/%u requested for inode %lu\n",
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 4df5e95801b4..a99588673566 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3056,7 +3056,7 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
                  * hook to the iocb.
                  */
                 iocb->private = NULL;
-                EXT4_I(inode)->cur_aio_dio = NULL;
+                ext4_inode_aio_set(inode, NULL);
                 if (!is_sync_kiocb(iocb)) {
                         ext4_io_end_t *io_end =
                                 ext4_init_io_end(inode, GFP_NOFS);
@@ -3073,7 +3073,7 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
                          * is a unwritten extents needs to be converted
                          * when IO is completed.
                          */
-                        EXT4_I(inode)->cur_aio_dio = iocb->private;
+                        ext4_inode_aio_set(inode, io_end);
                 }
 
                 if (overwrite)
@@ -3093,7 +3093,7 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
                                                  NULL,
                                                  DIO_LOCKING);
                 if (iocb->private)
-                        EXT4_I(inode)->cur_aio_dio = NULL;
+                        ext4_inode_aio_set(inode, NULL);
                 /*
                  * The io_end structure takes a reference to the inode,
                  * that structure needs to be destroyed and the
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ae456321c5bf..e05267ab1f81 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -965,7 +965,6 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
         ei->jinode = NULL;
         INIT_LIST_HEAD(&ei->i_completed_io_list);
         spin_lock_init(&ei->i_completed_io_lock);
-        ei->cur_aio_dio = NULL;
         ei->i_sync_tid = 0;
         ei->i_datasync_tid = 0;
         atomic_set(&ei->i_ioend_count, 0);