xfs: don't use ioends for direct write completions

We only need to communicate two bits of information to the direct I/O
completion handler:

 (1) do we need to convert any unwritten extents in the range
 (2) do we need to check if we need to update the inode size based
     on the range passed to the completion handler

We can use the private data passed to the get_block handler and the
completion handler as a simple bitmask to communicate this information
instead of the current complicated infrastructure reusing the ioends
from the buffer I/O path, and thus avoiding a memory allocation and
a context switch for any non-trivial direct write.  As a nice side
effect we also decouple the direct I/O path implementation from that
of the buffered I/O path.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
This commit is contained in:
Christoph Hellwig
2016-02-08 14:40:51 +11:00
committed by Dave Chinner
parent 187372a3b9
commit 273dda76f7
2 changed files with 77 additions and 152 deletions

View File

@@ -1296,11 +1296,7 @@ DEFINE_IOMAP_EVENT(xfs_map_blocks_found);
DEFINE_IOMAP_EVENT(xfs_map_blocks_alloc);
DEFINE_IOMAP_EVENT(xfs_get_blocks_found);
DEFINE_IOMAP_EVENT(xfs_get_blocks_alloc);
DEFINE_IOMAP_EVENT(xfs_gbmap_direct);
DEFINE_IOMAP_EVENT(xfs_gbmap_direct_new);
DEFINE_IOMAP_EVENT(xfs_gbmap_direct_update);
DEFINE_IOMAP_EVENT(xfs_gbmap_direct_none);
DEFINE_IOMAP_EVENT(xfs_gbmap_direct_endio);
DEFINE_IOMAP_EVENT(xfs_get_blocks_map_direct);
DECLARE_EVENT_CLASS(xfs_simple_io_class,
TP_PROTO(struct xfs_inode *ip, xfs_off_t offset, ssize_t count),
@@ -1340,6 +1336,9 @@ DEFINE_SIMPLE_IO_EVENT(xfs_unwritten_convert);
DEFINE_SIMPLE_IO_EVENT(xfs_get_blocks_notfound);
DEFINE_SIMPLE_IO_EVENT(xfs_setfilesize);
DEFINE_SIMPLE_IO_EVENT(xfs_zero_eof);
DEFINE_SIMPLE_IO_EVENT(xfs_end_io_direct_write);
DEFINE_SIMPLE_IO_EVENT(xfs_end_io_direct_write_unwritten);
DEFINE_SIMPLE_IO_EVENT(xfs_end_io_direct_write_append);
DECLARE_EVENT_CLASS(xfs_itrunc_class,
TP_PROTO(struct xfs_inode *ip, xfs_fsize_t new_size),