fs/btrfs/raid56.h

1 /* SPDX-License-Identifier: GPL-2.0 */
3  * Copyright (C) 2012 Fusion-io  All rights reserved.
35 	 * bio_list and bio_list_lock are used to add more bios into the stripe
43 	 * plugging code to collect partial bios while plugged.  The stripe
44 	 * locking code also uses it to hand off the stripe lock to the next
49 	/* Flags that tell us if it is safe to merge with this bio. */
58 	/* How many pages there are for the full stripe including P/Q */
61 	/* How many sectors there are for the full stripe including P/Q */
70 	/* How many pages there are for each stripe */
73 	/* How many sectors there are for each stripe */
81 	 * rbio maps to a full stripe or not.
91 	/* Bitmap to record which horizontal stripe has data */
94 	/* Allocated with stripe_nsectors-many bits for finish_*() calls */
99 	 * to hold them both and setup their locations when the rbio is
104 	 * Pointers to pages that we allocated for reading/writing stripes
109 	/* Pointers to the sectors in the bio_list, for faster lookup */
113 	 * For subpage support, we need to map each sector to above
118 	/* Allocated with real_stripes-many pointers for finish_*() calls */
123 	 * Each bit is corresponding to one sector in either bio_sectors[] or
128 	 * Thus making it much harder to iterate.
147  * by RAID56 to each physical device.
149  * No matter signed or not, (-1) is always the one indicating we can not grab
169 	return map->num_stripes - btrfs_nr_parity_stripes(map->type);  in nr_data_stripes()
174 	return bioc->num_stripes - btrfs_nr_parity_stripes(bioc->map_type);  in nr_bioc_data_stripes()
177 #define RAID5_P_STRIPE ((u64)-2)
178 #define RAID6_Q_STRIPE ((u64)-1)