xref: /linux-6.15/include/linux/badblocks.h (revision d3b407fb)
1 #ifndef _LINUX_BADBLOCKS_H
2 #define _LINUX_BADBLOCKS_H
3 
4 #include <linux/seqlock.h>
5 #include <linux/kernel.h>
6 #include <linux/stddef.h>
7 #include <linux/types.h>
8 
9 #define BB_LEN_MASK	(0x00000000000001FFULL)
10 #define BB_OFFSET_MASK	(0x7FFFFFFFFFFFFE00ULL)
11 #define BB_ACK_MASK	(0x8000000000000000ULL)
12 #define BB_MAX_LEN	512
13 #define BB_OFFSET(x)	(((x) & BB_OFFSET_MASK) >> 9)
14 #define BB_LEN(x)	(((x) & BB_LEN_MASK) + 1)
15 #define BB_ACK(x)	(!!((x) & BB_ACK_MASK))
16 #define BB_MAKE(a, l, ack) (((a)<<9) | ((l)-1) | ((u64)(!!(ack)) << 63))
17 
18 /* Bad block numbers are stored sorted in a single page.
19  * 64bits is used for each block or extent.
20  * 54 bits are sector number, 9 bits are extent size,
21  * 1 bit is an 'acknowledged' flag.
22  */
23 #define MAX_BADBLOCKS	(PAGE_SIZE/8)
24 
25 struct badblocks {
26 	int count;		/* count of bad blocks */
27 	int unacked_exist;	/* there probably are unacknowledged
28 				 * bad blocks.  This is only cleared
29 				 * when a read discovers none
30 				 */
31 	int shift;		/* shift from sectors to block size
32 				 * a -ve shift means badblocks are
33 				 * disabled.*/
34 	u64 *page;		/* badblock list */
35 	int changed;
36 	seqlock_t lock;
37 	sector_t sector;
38 	sector_t size;		/* in sectors */
39 };
40 
41 int badblocks_check(struct badblocks *bb, sector_t s, int sectors,
42 		   sector_t *first_bad, int *bad_sectors);
43 int badblocks_set(struct badblocks *bb, sector_t s, int sectors,
44 			int acknowledged);
45 int badblocks_clear(struct badblocks *bb, sector_t s, int sectors);
46 void ack_all_badblocks(struct badblocks *bb);
47 ssize_t badblocks_show(struct badblocks *bb, char *page, int unack);
48 ssize_t badblocks_store(struct badblocks *bb, const char *page, size_t len,
49 			int unack);
50 int badblocks_init(struct badblocks *bb, int enable);
51 void badblocks_exit(struct badblocks *bb);
52 
53 #endif
54