pnfsblock: alloc short extent before submit bio

As discussed earlier, it is better for block client to allocate memory for
tracking extents state before submitting bio. So the patch does it by allocating
a short_extent for every INVALID extent touched by write pagelist and for
every zeroing page we created, saving them in layout header. Then in end_io we
can just use them to create commit list items and avoid memory allocation there.

Signed-off-by: Peng Tao <peng_tao@emc.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 8 insertions, 1 deletions

diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h
index 60728acc7b99..e31a2df28e70 100644
--- a/fs/nfs/blocklayout/blocklayout.h
+++ b/fs/nfs/blocklayout/blocklayout.h
@@ -70,6 +70,7 @@ struct pnfs_inval_markings {
         spinlock_t      im_lock;
         struct my_tree  im_tree;        /* Sectors that need LAYOUTCOMMIT */
         sector_t        im_block_size;  /* Server blocksize in sectors */
+        struct list_head im_extents;    /* Short extents for INVAL->RW conversion */
 };
 
 struct pnfs_inval_tracking {
@@ -105,6 +106,7 @@ BL_INIT_INVAL_MARKS(struct pnfs_inval_markings *marks, sector_t blocksize)
 {
         spin_lock_init(&marks->im_lock);
         INIT_LIST_HEAD(&marks->im_tree.mtt_stub);
+        INIT_LIST_HEAD(&marks->im_extents);
         marks->im_block_size = blocksize;
         marks->im_tree.mtt_step_size = min((sector_t)PAGE_CACHE_SECTORS,
                                            blocksize);
@@ -199,6 +201,11 @@ void clean_pnfs_block_layoutupdate(struct pnfs_block_layout *bl,
 int bl_add_merge_extent(struct pnfs_block_layout *bl,
                          struct pnfs_block_extent *new);
 int bl_mark_for_commit(struct pnfs_block_extent *be,
-                        sector_t offset, sector_t length);
+                        sector_t offset, sector_t length,
+                        struct pnfs_block_short_extent *new);
+int bl_push_one_short_extent(struct pnfs_inval_markings *marks);
+struct pnfs_block_short_extent *
+bl_pop_one_short_extent(struct pnfs_inval_markings *marks);
+void bl_free_short_extents(struct pnfs_inval_markings *marks, int num_to_free);
 
 #endif /* FS_NFS_NFS4BLOCKLAYOUT_H */