[XFS] Initial pass at going directly-to-bio on the buffered IO path. This
allows us to submit much larger I/Os instead of sending down lots of small
buffer_heads. To do this we need to have a rather complicated I/O
submission and completion tracking infrastructure. Part of the latter has
been merged already a long time ago for direct I/O support. Part of the
problem is that we need to track sub-pagesize regions and for that we
still need buffer_heads for the time beeing. Long-term I hope we can move
to better data strucutures and/or maybe move this to fs/mpage.c instead of
having it in XFS. Original patch from Nathan Scott with various updates
from David Chinner and Christoph Hellwig.
SGI-PV: 947118
SGI-Modid: xfs-linux-melb:xfs-kern:203822a
Signed-off-by: Christoph Hellwig <hch@sgi.com>
Signed-off-by: Nathan Scott <nathans@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_aops.h b/fs/xfs/linux-2.6/xfs_aops.h
index 4720758..55339dd 100644
--- a/fs/xfs/linux-2.6/xfs_aops.h
+++ b/fs/xfs/linux-2.6/xfs_aops.h
@@ -23,14 +23,24 @@
typedef void (*xfs_ioend_func_t)(void *);
+/*
+ * xfs_ioend struct manages large extent writes for XFS.
+ * It can manage several multi-page bio's at once.
+ */
typedef struct xfs_ioend {
+ struct xfs_ioend *io_list; /* next ioend in chain */
+ unsigned int io_type; /* delalloc / unwritten */
unsigned int io_uptodate; /* I/O status register */
atomic_t io_remaining; /* hold count */
struct vnode *io_vnode; /* file being written to */
struct buffer_head *io_buffer_head;/* buffer linked list head */
+ struct buffer_head *io_buffer_tail;/* buffer linked list tail */
size_t io_size; /* size of the extent */
xfs_off_t io_offset; /* offset in the file */
struct work_struct io_work; /* xfsdatad work queue */
} xfs_ioend_t;
+extern struct address_space_operations linvfs_aops;
+extern int linvfs_get_block(struct inode *, sector_t, struct buffer_head *, int);
+
#endif /* __XFS_IOPS_H__ */