pnfsblock: bl_find_get_extent

Implement bl_find_get_extent(), one of the core extent manipulation
routines.

[pnfsblock: Lookup list entry of layouts and tags in reverse order]
Signed-off-by: Zhang Jingwang <zhangjingwang@nrchpc.ac.cn>
Signed-off-by: Fred Isaman <iisaman@citi.umich.edu>
Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Jim Rees <rees@umich.edu>

pnfsblock: fix print format warnings for sector_t and size_t

gcc spews warnings about these on x86_64, e.g.:
fs/nfs/blocklayout/blocklayout.c:74: warning: format ‘%Lu’ expects type ‘long long unsigned int’, but argument 2 has type ‘sector_t’
fs/nfs/blocklayout/blocklayout.c:388: warning: format ‘%d’ expects type ‘int’, but argument 5 has type ‘size_t’

Signed-off-by: Benny Halevy <bhalevy@panasas.com>
Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Jim Rees <rees@umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h
index d645880..3e1b5fc 100644
--- a/fs/nfs/blocklayout/blocklayout.h
+++ b/fs/nfs/blocklayout/blocklayout.h
@@ -153,6 +153,9 @@
 void bl_free_block_dev(struct pnfs_block_dev *bdev);
 
 /* extents.c */
+struct pnfs_block_extent *
+bl_find_get_extent(struct pnfs_block_layout *bl, sector_t isect,
+		struct pnfs_block_extent **cow_read);
 void bl_put_extent(struct pnfs_block_extent *be);
 struct pnfs_block_extent *bl_alloc_extent(void);
 int bl_add_merge_extent(struct pnfs_block_layout *bl,