Btrfs: add RAID 5/6 BTRFS_RBIO_REBUILD_MISSING operation
The current RAID 5/6 recovery code isn't quite prepared to handle
missing devices. In particular, it expects a bio that we previously
attempted to use in the read path, meaning that it has valid pages
allocated. However, missing devices have a NULL blkdev, and we can't
call bio_add_page() on a bio with a NULL blkdev. We could do manual
manipulation of bio->bi_io_vec, but that's pretty gross. So instead, add
a separate path that allows us to manually add pages to the rbio.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/raid56.h b/fs/btrfs/raid56.h
index 2b5d797..8b69469 100644
--- a/fs/btrfs/raid56.h
+++ b/fs/btrfs/raid56.h
@@ -48,15 +48,21 @@
int raid56_parity_write(struct btrfs_root *root, struct bio *bio,
struct btrfs_bio *bbio, u64 stripe_len);
+void raid56_add_scrub_pages(struct btrfs_raid_bio *rbio, struct page *page,
+ u64 logical);
+
struct btrfs_raid_bio *
raid56_parity_alloc_scrub_rbio(struct btrfs_root *root, struct bio *bio,
struct btrfs_bio *bbio, u64 stripe_len,
struct btrfs_device *scrub_dev,
unsigned long *dbitmap, int stripe_nsectors);
-void raid56_parity_add_scrub_pages(struct btrfs_raid_bio *rbio,
- struct page *page, u64 logical);
void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio);
+struct btrfs_raid_bio *
+raid56_alloc_missing_rbio(struct btrfs_root *root, struct bio *bio,
+ struct btrfs_bio *bbio, u64 length);
+void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio);
+
int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info);
void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info);
#endif