jim owens
2010-Jan-04 21:13 UTC
[RFC 08/12 PATCH] Btrfs: add direct I/O helper routines to decode em map_lookup.
Direct I/O needs the total number of block devices and the struct block_device for each to allocate control structures prior to building bios for an extent. When building a bio, the device''s base physical address of the chunk is needed. Signed-off-by: jim owens <jowens@hp.com> --- fs/btrfs/volumes.c | 15 +++++++++++++++ fs/btrfs/volumes.h | 3 +++ 2 files changed, 18 insertions(+), 0 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 48727ee..6aa04e4 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -2614,6 +2614,21 @@ static int find_live_mirror(struct map_lookup *map, int first, int num, return optimal; } +int btrfs_map_stripe_count(struct extent_map *em) +{ + return ((struct map_lookup *)em->bdev)->num_stripes; +} + +struct block_device *btrfs_map_stripe_bdev(struct extent_map *em, int stripe) +{ + return ((struct map_lookup *)em->bdev)->stripes[stripe].dev->bdev; +} + +u64 btrfs_map_stripe_physical(struct extent_map *em, int stripe) +{ + return ((struct map_lookup *)em->bdev)->stripes[stripe].physical; +} + void btrfs_map_to_stripe(struct extent_map *em, int rw, int mirror_num, u64 logical, u64 *length, struct btrfs_stripe_info *stripe_info) diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 76c4394..226200d 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -192,4 +192,7 @@ int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset); int find_free_dev_extent(struct btrfs_trans_handle *trans, struct btrfs_device *device, u64 num_bytes, u64 *start, u64 *max_avail); +int btrfs_map_stripe_count(struct extent_map *em); +struct block_device *btrfs_map_stripe_bdev(struct extent_map *em, int stripe); +u64 btrfs_map_stripe_physical(struct extent_map *em, int stripe); #endif -- 1.5.6.3 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html