md: beginnings of bad block management.
This the first step in allowing md to track bad-blocks per-device so
that we can fail individual blocks rather than the whole device.
This patch just adds a data structure for recording bad blocks, with
routines to add, remove, search the list.
Signed-off-by: NeilBrown <neilb@suse.de>
Reviewed-by: Namhyung Kim <namhyung@gmail.com>
diff --git a/drivers/md/md.h b/drivers/md/md.h
index 7d906a9..85af843 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -29,6 +29,13 @@
typedef struct mddev_s mddev_t;
typedef struct mdk_rdev_s mdk_rdev_t;
+/* Bad block numbers are stored sorted in a single page.
+ * 64bits is used for each block or extent.
+ * 54 bits are sector number, 9 bits are extent size,
+ * 1 bit is an 'acknowledged' flag.
+ */
+#define MD_MAX_BADBLOCKS (PAGE_SIZE/8)
+
/*
* MD's 'extended' device
*/
@@ -111,8 +118,47 @@
struct sysfs_dirent *sysfs_state; /* handle for 'state'
* sysfs entry */
+
+ struct badblocks {
+ int count; /* count of bad blocks */
+ int shift; /* shift from sectors to block size
+ * a -ve shift means badblocks are
+ * disabled.*/
+ u64 *page; /* badblock list */
+ int changed;
+ seqlock_t lock;
+ } badblocks;
};
+#define BB_LEN_MASK (0x00000000000001FFULL)
+#define BB_OFFSET_MASK (0x7FFFFFFFFFFFFE00ULL)
+#define BB_ACK_MASK (0x8000000000000000ULL)
+#define BB_MAX_LEN 512
+#define BB_OFFSET(x) (((x) & BB_OFFSET_MASK) >> 9)
+#define BB_LEN(x) (((x) & BB_LEN_MASK) + 1)
+#define BB_ACK(x) (!!((x) & BB_ACK_MASK))
+#define BB_MAKE(a, l, ack) (((a)<<9) | ((l)-1) | ((u64)(!!(ack)) << 63))
+
+extern int md_is_badblock(struct badblocks *bb, sector_t s, int sectors,
+ sector_t *first_bad, int *bad_sectors);
+static inline int is_badblock(mdk_rdev_t *rdev, sector_t s, int sectors,
+ sector_t *first_bad, int *bad_sectors)
+{
+ if (unlikely(rdev->badblocks.count)) {
+ int rv = md_is_badblock(&rdev->badblocks, rdev->data_offset + s,
+ sectors,
+ first_bad, bad_sectors);
+ if (rv)
+ *first_bad -= rdev->data_offset;
+ return rv;
+ }
+ return 0;
+}
+extern int rdev_set_badblocks(mdk_rdev_t *rdev, sector_t s, int sectors,
+ int acknowledged);
+extern int rdev_clear_badblocks(mdk_rdev_t *rdev, sector_t s, int sectors);
+extern void md_ack_all_badblocks(struct badblocks *bb);
+
struct mddev_s
{
void *private;
@@ -517,7 +563,7 @@
extern int md_run(mddev_t *mddev);
extern void md_stop(mddev_t *mddev);
extern void md_stop_writes(mddev_t *mddev);
-extern void md_rdev_init(mdk_rdev_t *rdev);
+extern int md_rdev_init(mdk_rdev_t *rdev);
extern void mddev_suspend(mddev_t *mddev);
extern void mddev_resume(mddev_t *mddev);
