* [RFC PATCH v1 1/6] badblocks: add more helper structure and routines in badblocks.h
2021-03-02 4:02 [RFC PATCH v1 0/6] badblocks improvement for multiple bad block ranges Coly Li
@ 2021-03-02 4:02 ` Coly Li
2021-03-03 8:20 ` Hannes Reinecke
2021-03-02 4:02 ` [RFC PATCH v1 2/6] badblocks: add helper routines for badblock ranges handling Coly Li
` (4 subsequent siblings)
5 siblings, 1 reply; 9+ messages in thread
From: Coly Li @ 2021-03-02 4:02 UTC (permalink / raw)
To: linux-block, axboe, dan.j.williams, vishal.l.verma, neilb
Cc: antlists, linux-kernel, linux-raid, linux-nvdimm, Coly Li
This patch adds the following helper structure and routines into
badblocks.h,
- struct bad_context
This structure is used in improved badblocks code for bad table
iteration.
- BB_END()
The macro to culculate end LBA of a bad range record from bad
table.
- badblocks_full() and badblocks_empty()
The inline routines to check whether bad table is full or empty.
- set_changed() and clear_changed()
The inline routines to set and clear 'changed' tag from struct
badblocks.
These new helper structure and routines can help to make the code more
clear, they will be used in the improved badblocks code in following
patches.
Signed-off-by: Coly Li <colyli@suse.de>
---
include/linux/badblocks.h | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/include/linux/badblocks.h b/include/linux/badblocks.h
index 2426276b9bd3..166161842d1f 100644
--- a/include/linux/badblocks.h
+++ b/include/linux/badblocks.h
@@ -15,6 +15,7 @@
#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_END(x) (BB_OFFSET(x) + BB_LEN(x))
#define BB_MAKE(a, l, ack) (((a)<<9) | ((l)-1) | ((u64)(!!(ack)) << 63))
/* Bad block numbers are stored sorted in a single page.
@@ -41,6 +42,14 @@ struct badblocks {
sector_t size; /* in sectors */
};
+struct bad_context {
+ sector_t start;
+ sector_t len;
+ int ack;
+ sector_t orig_start;
+ sector_t orig_len;
+};
+
int badblocks_check(struct badblocks *bb, sector_t s, int sectors,
sector_t *first_bad, int *bad_sectors);
int badblocks_set(struct badblocks *bb, sector_t s, int sectors,
@@ -63,4 +72,27 @@ static inline void devm_exit_badblocks(struct device *dev, struct badblocks *bb)
}
badblocks_exit(bb);
}
+
+static inline int badblocks_full(struct badblocks *bb)
+{
+ return (bb->count >= MAX_BADBLOCKS);
+}
+
+static inline int badblocks_empty(struct badblocks *bb)
+{
+ return (bb->count == 0);
+}
+
+static inline void set_changed(struct badblocks *bb)
+{
+ if (bb->changed != 1)
+ bb->changed = 1;
+}
+
+static inline void clear_changed(struct badblocks *bb)
+{
+ if (bb->changed != 0)
+ bb->changed = 0;
+}
+
#endif
--
2.26.2
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^ permalink raw reply related [flat|nested] 9+ messages in thread* Re: [RFC PATCH v1 1/6] badblocks: add more helper structure and routines in badblocks.h
2021-03-02 4:02 ` [RFC PATCH v1 1/6] badblocks: add more helper structure and routines in badblocks.h Coly Li
@ 2021-03-03 8:20 ` Hannes Reinecke
2021-03-03 11:45 ` Coly Li
0 siblings, 1 reply; 9+ messages in thread
From: Hannes Reinecke @ 2021-03-03 8:20 UTC (permalink / raw)
To: Coly Li, linux-block, axboe, dan.j.williams, vishal.l.verma, neilb
Cc: antlists, linux-kernel, linux-raid, linux-nvdimm
On 3/2/21 5:02 AM, Coly Li wrote:
> This patch adds the following helper structure and routines into
> badblocks.h,
> - struct bad_context
> This structure is used in improved badblocks code for bad table
> iteration.
> - BB_END()
> The macro to culculate end LBA of a bad range record from bad
> table.
> - badblocks_full() and badblocks_empty()
> The inline routines to check whether bad table is full or empty.
> - set_changed() and clear_changed()
> The inline routines to set and clear 'changed' tag from struct
> badblocks.
>
> These new helper structure and routines can help to make the code more
> clear, they will be used in the improved badblocks code in following
> patches.
>
> Signed-off-by: Coly Li <colyli@suse.de>
> ---
> include/linux/badblocks.h | 32 ++++++++++++++++++++++++++++++++
> 1 file changed, 32 insertions(+)
>
> diff --git a/include/linux/badblocks.h b/include/linux/badblocks.h
> index 2426276b9bd3..166161842d1f 100644
> --- a/include/linux/badblocks.h
> +++ b/include/linux/badblocks.h
> @@ -15,6 +15,7 @@
> #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_END(x) (BB_OFFSET(x) + BB_LEN(x))
> #define BB_MAKE(a, l, ack) (((a)<<9) | ((l)-1) | ((u64)(!!(ack)) << 63))
>
> /* Bad block numbers are stored sorted in a single page.
> @@ -41,6 +42,14 @@ struct badblocks {
> sector_t size; /* in sectors */
> };
>
> +struct bad_context {
> + sector_t start;
> + sector_t len;
> + int ack;
> + sector_t orig_start;
> + sector_t orig_len;
> +};
> +
Maybe rename it to 'badblocks_context'.
It's not the context which is bad ...
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@suse.de +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), GF: Felix Imendörffer
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^ permalink raw reply [flat|nested] 9+ messages in thread* Re: [RFC PATCH v1 1/6] badblocks: add more helper structure and routines in badblocks.h
2021-03-03 8:20 ` Hannes Reinecke
@ 2021-03-03 11:45 ` Coly Li
0 siblings, 0 replies; 9+ messages in thread
From: Coly Li @ 2021-03-03 11:45 UTC (permalink / raw)
To: Hannes Reinecke
Cc: antlists, axboe, linux-kernel, linux-raid, linux-nvdimm,
linux-block, neilb
On 3/3/21 4:20 PM, Hannes Reinecke wrote:
> On 3/2/21 5:02 AM, Coly Li wrote:
>> This patch adds the following helper structure and routines into
>> badblocks.h,
>> - struct bad_context
>> This structure is used in improved badblocks code for bad table
>> iteration.
>> - BB_END()
>> The macro to culculate end LBA of a bad range record from bad
>> table.
>> - badblocks_full() and badblocks_empty()
>> The inline routines to check whether bad table is full or empty.
>> - set_changed() and clear_changed()
>> The inline routines to set and clear 'changed' tag from struct
>> badblocks.
>>
>> These new helper structure and routines can help to make the code more
>> clear, they will be used in the improved badblocks code in following
>> patches.
>>
>> Signed-off-by: Coly Li <colyli@suse.de>
>> ---
>> include/linux/badblocks.h | 32 ++++++++++++++++++++++++++++++++
>> 1 file changed, 32 insertions(+)
>>
>> diff --git a/include/linux/badblocks.h b/include/linux/badblocks.h
>> index 2426276b9bd3..166161842d1f 100644
>> --- a/include/linux/badblocks.h
>> +++ b/include/linux/badblocks.h
>> @@ -15,6 +15,7 @@
>> #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_END(x) (BB_OFFSET(x) + BB_LEN(x))
>> #define BB_MAKE(a, l, ack) (((a)<<9) | ((l)-1) | ((u64)(!!(ack)) << 63))
>>
>> /* Bad block numbers are stored sorted in a single page.
>> @@ -41,6 +42,14 @@ struct badblocks {
>> sector_t size; /* in sectors */
>> };
>>
>> +struct bad_context {
>> + sector_t start;
>> + sector_t len;
>> + int ack;
>> + sector_t orig_start;
>> + sector_t orig_len;
>> +};
>> +
> Maybe rename it to 'badblocks_context'.
> It's not the context which is bad ...
>
Copied, I will modify it in next version.
Thanks for the suggestion.
Coly Li
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^ permalink raw reply [flat|nested] 9+ messages in thread
* [RFC PATCH v1 2/6] badblocks: add helper routines for badblock ranges handling
2021-03-02 4:02 [RFC PATCH v1 0/6] badblocks improvement for multiple bad block ranges Coly Li
2021-03-02 4:02 ` [RFC PATCH v1 1/6] badblocks: add more helper structure and routines in badblocks.h Coly Li
@ 2021-03-02 4:02 ` Coly Li
2021-03-02 4:02 ` [RFC PATCH v1 3/6] badblocks: improvement badblocks_set() for multiple " Coly Li
` (3 subsequent siblings)
5 siblings, 0 replies; 9+ messages in thread
From: Coly Li @ 2021-03-02 4:02 UTC (permalink / raw)
To: linux-block, axboe, dan.j.williams, vishal.l.verma, neilb
Cc: antlists, linux-kernel, linux-raid, linux-nvdimm, Coly Li
This patch adds several helper routines to improve badblock ranges
handling. These helper routines will be used later in the improved
version of badblocks_set()/badblocks_clear()/badblocks_check().
- Helpers prev_by_hint() and prev_badblocks() are used to find the bad
range from bad table which the searching range starts at or after.
- The following helpers are to decide the relative layout between the
manipulating range and existing bad block range from bad table.
- can_merge_behind()
Return 'true' if the manipulating range can backward merge with the
bad block range.
- can_merge_front()
Return 'true' if the manipulating range can forward merge with the
bad block range.
- can_combine_front()
Return 'true' if two adjacent bad block ranges before the
manipulating range can be merged.
- overlap_front()
Return 'true' if the manipulating range exactly overlaps with the
bad block range in front of its range.
- overlap_behind()
Return 'true' if the manipulating range exactly overlaps with the
bad block range behind its range.
- can_front_overwrite()
Return 'true' if the manipulating range can forward overwrite the
bad block range in front of its range.
- The following helpers are to add the manipulating range into the bad
block table. Different routine is called with the specific relative
layout between the maniplating range and other bad block range in the
bad block table.
- behind_merge()
Merge the maniplating range with the bad block range behind its
range, and return the number of merged length in unit of sector.
- front_merge()
Merge the maniplating range with the bad block range in front of
its range, and return the number of merged length in unit of sector.
- front_combine()
Combine the two adjacent bad block ranges before the manipulating
range into a larger one.
- front_overwrite()
Overwrite partial of whole bad block range which is in front of the
manipulating range. The overwrite may split existing bad block range
and generate more bad block ranges into the bad block table.
- insert_at()
Insert the manipulating range at a specific location in the bad
block table.
All the above helpers are used in later patches to improve the bad block
ranges handling for badblocks_set()/badblocks_clear()/badblocks_check().
Signed-off-by: Coly Li <colyli@suse.de>
---
block/badblocks.c | 374 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 374 insertions(+)
diff --git a/block/badblocks.c b/block/badblocks.c
index d39056630d9c..fd76bbe7b5a2 100644
--- a/block/badblocks.c
+++ b/block/badblocks.c
@@ -16,6 +16,380 @@
#include <linux/types.h>
#include <linux/slab.h>
+/*
+ * Find the range starts at-or-before 's' from bad table. The search
+ * starts from index 'hint' and stops at index 'hint_end' from the bad
+ * table.
+ */
+static int prev_by_hint(struct badblocks *bb, sector_t s, int hint)
+{
+ u64 *p = bb->page;
+ int ret = -1;
+ int hint_end = hint + 2;
+
+ while ((hint < hint_end) && ((hint + 1) <= bb->count) &&
+ (BB_OFFSET(p[hint]) <= s)) {
+ if ((hint + 1) == bb->count || BB_OFFSET(p[hint + 1]) > s) {
+ ret = hint;
+ break;
+ }
+ hint++;
+ }
+
+ return ret;
+}
+
+/*
+ * Find the range starts at-or-before bad->start. If 'hint' is provided
+ * (hint >= 0) then search in the bad table from hint firstly. It is
+ * very probably the wanted bad range can be found from the hint index,
+ * then the unnecessary while-loop iteration can be avoided.
+ */
+static int prev_badblocks(struct badblocks *bb, struct bad_context *bad,
+ int hint)
+{
+ u64 *p;
+ int lo, hi;
+ sector_t s = bad->start;
+ int ret = -1;
+
+ if (!bb->count)
+ goto out;
+
+ if (hint >= 0) {
+ ret = prev_by_hint(bb, s, hint);
+ if (ret >= 0)
+ goto out;
+ }
+
+ lo = 0;
+ hi = bb->count;
+ p = bb->page;
+
+ while (hi - lo > 1) {
+ int mid = (lo + hi)/2;
+ sector_t a = BB_OFFSET(p[mid]);
+
+ if (a <= s)
+ lo = mid;
+ else
+ hi = mid;
+ }
+
+ if (BB_OFFSET(p[lo]) <= s)
+ ret = lo;
+out:
+ return ret;
+}
+
+/*
+ * Return 'true' if the range indicated by 'bad' can be backward merged
+ * with the bad range (from the bad table) index by 'behind'.
+ */
+static bool can_merge_behind(struct badblocks *bb, struct bad_context *bad,
+ int behind)
+{
+ u64 *p = bb->page;
+ sector_t s = bad->start;
+ sector_t sectors = bad->len;
+ int ack = bad->ack;
+
+ if ((s <= BB_OFFSET(p[behind])) &&
+ ((s + sectors) >= BB_OFFSET(p[behind])) &&
+ ((BB_END(p[behind]) - s) <= BB_MAX_LEN) &&
+ BB_ACK(p[behind]) == ack)
+ return true;
+ return false;
+}
+
+/*
+ * Do backward merge for range indicated by 'bad' and the bad range
+ * (from the bad table) indexed by 'behind'. The return value is merged
+ * sectors from bad->len.
+ */
+static int behind_merge(struct badblocks *bb, struct bad_context *bad,
+ int behind)
+{
+ u64 *p = bb->page;
+ sector_t s = bad->start;
+ sector_t sectors = bad->len;
+ int ack = bad->ack;
+ int merged = 0;
+
+ WARN_ON(s > BB_OFFSET(p[behind]));
+ WARN_ON((s + sectors) < BB_OFFSET(p[behind]));
+
+ if (s < BB_OFFSET(p[behind])) {
+ WARN_ON((BB_LEN(p[behind]) + merged) >= BB_MAX_LEN);
+
+ merged = min_t(sector_t, sectors, BB_OFFSET(p[behind]) - s);
+ p[behind] = BB_MAKE(s, BB_LEN(p[behind]) + merged, ack);
+ } else {
+ merged = min_t(sector_t, sectors, BB_LEN(p[behind]));
+ }
+
+ WARN_ON(merged == 0);
+
+ return merged;
+}
+
+/*
+ * Return 'true' if the range indicated by 'bad' can be forward
+ * merged with the bad range (from the bad table) indexed by 'prev'.
+ */
+static bool can_merge_front(struct badblocks *bb, int prev,
+ struct bad_context *bad)
+{
+ u64 *p = bb->page;
+ sector_t s = bad->start;
+ int ack = bad->ack;
+
+ if (BB_ACK(p[prev]) == ack &&
+ (s < BB_END(p[prev]) ||
+ (s == BB_END(p[prev]) && (BB_LEN(p[prev]) < BB_MAX_LEN))))
+ return true;
+ return false;
+}
+
+/*
+ * Do forward merge for range indicated by 'bad' and the bad range
+ * (from bad table) indexed by 'prev'. The return value is sectors
+ * merged from bad->len.
+ */
+static int front_merge(struct badblocks *bb, int prev, struct bad_context *bad)
+{
+ sector_t sectors = bad->len;
+ sector_t s = bad->start;
+ int ack = bad->ack;
+ u64 *p = bb->page;
+ int merged = 0;
+
+ WARN_ON(s > BB_END(p[prev]));
+
+ if (s < BB_END(p[prev])) {
+ merged = min_t(sector_t, sectors, BB_END(p[prev]) - s);
+ } else {
+ merged = min_t(sector_t, sectors, BB_MAX_LEN - BB_LEN(p[prev]));
+ if ((prev + 1) < bb->count &&
+ merged > (BB_OFFSET(p[prev + 1]) - BB_END(p[prev]))) {
+ merged = BB_OFFSET(p[prev + 1]) - BB_END(p[prev]);
+ }
+
+ p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
+ BB_LEN(p[prev]) + merged, ack);
+ }
+
+ return merged;
+}
+
+/*
+ * 'Combine' is a special case which can_merge_front() is not able to
+ * handle: If a bad range (indexed by 'prev' from bad table) exactly
+ * starts as bad->start, and the bad range ahead of 'prev' (indexed by
+ * 'prev - 1' from bad table) exactly ends at where 'prev' starts, and
+ * the sum of their lengths does not exceed BB_MAX_LEN limitation, then
+ * these two bad range (from bad table) can be combined.
+ *
+ * Return 'true' if bad ranges indexed by 'prev' and 'prev - 1' from bad
+ * table can be combined.
+ */
+static bool can_combine_front(struct badblocks *bb, int prev,
+ struct bad_context *bad)
+{
+ u64 *p = bb->page;
+
+ if ((prev > 0) &&
+ (BB_OFFSET(p[prev]) == bad->start) &&
+ (BB_END(p[prev - 1]) == BB_OFFSET(p[prev])) &&
+ (BB_LEN(p[prev - 1]) + BB_LEN(p[prev]) <= BB_MAX_LEN) &&
+ (BB_ACK(p[prev - 1]) == BB_ACK(p[prev])))
+ return true;
+ return false;
+}
+
+/*
+ * Combine the bad ranges indexed by 'prev' and 'prev - 1' (from bad
+ * table) into one larger bad range, and the new range is indexed by
+ * 'prev - 1'.
+ */
+static void front_combine(struct badblocks *bb, int prev)
+{
+ u64 *p = bb->page;
+
+ p[prev - 1] = BB_MAKE(BB_OFFSET(p[prev - 1]),
+ BB_LEN(p[prev - 1]) + BB_LEN(p[prev]),
+ BB_ACK(p[prev]));
+ if ((prev + 1) < bb->count)
+ memmove(p + prev, p + prev + 1, (bb->count - prev - 1) * 8);
+}
+
+/*
+ * Return 'true' if the range indicated by 'bad' is exactly forward
+ * overlapped with the bad range (from bad table) indexed by 'front'.
+ * Exactly forward overlap means the bad range (from bad table) indexed
+ * by 'prev' does not cover the whole range indicated by 'bad'.
+ */
+static bool overlap_front(struct badblocks *bb, int front,
+ struct bad_context *bad)
+{
+ u64 *p = bb->page;
+
+ if (bad->start >= BB_OFFSET(p[front]) &&
+ bad->start < BB_END(p[front]))
+ return true;
+ return false;
+}
+
+/*
+ * Return 'true' if the range indicated by 'bad' is exactly backward
+ * overlapped with the bad range (from bad table) indexed by 'behind'.
+ */
+static bool overlap_behind(struct badblocks *bb, struct bad_context *bad,
+ int behind)
+{
+ u64 *p = bb->page;
+
+ if (bad->start < BB_OFFSET(p[behind]) &&
+ (bad->start + bad->len) > BB_OFFSET(p[behind]))
+ return true;
+ return false;
+}
+
+/*
+ * Return 'true' if the range indicated by 'bad' can overwrite the bad
+ * range (from bad table) indexed by 'prev'.
+ *
+ * The range indicated by 'bad' can overwrite the bad range indexed by
+ * 'prev' when,
+ * 1) The whole range indicated by 'bad' can cover partial or whole bad
+ * range (from bad table) indexed by 'prev'.
+ * 2) The ack value of 'bad' is larger or equal to the ack value of bad
+ * range 'prev'.
+ *
+ * If the overwriting doesn't cover the whole bad range (from bad table)
+ * indexed by 'prev', new range might be split from existing bad range,
+ * 1) The overwrite covers head or tail part of existing bad range, 1
+ * extra bad range will be split and added into the bad table.
+ * 2) The overwrite covers middle of existing bad range, 2 extra bad
+ * ranges will be split (ahead and after the overwritten range) and
+ * added into the bad table.
+ * The number of extra split ranges of the overwriting is stored in
+ * 'extra' and returned for the caller.
+ */
+static bool can_front_overwrite(struct badblocks *bb, int prev,
+ struct bad_context *bad, int *extra)
+{
+ u64 *p = bb->page;
+ int len;
+
+ WARN_ON(!overlap_front(bb, prev, bad));
+
+ if (BB_ACK(p[prev]) >= bad->ack)
+ return false;
+
+ if (BB_END(p[prev]) <= (bad->start + bad->len)) {
+ len = BB_END(p[prev]) - bad->start;
+ if (BB_OFFSET(p[prev]) == bad->start)
+ *extra = 0;
+ else
+ *extra = 1;
+
+ bad->len = len;
+ } else {
+ if (BB_OFFSET(p[prev]) == bad->start)
+ *extra = 1;
+ else
+ /*
+ * prev range will be split into two, beside the overwritten
+ * one, an extra slot needed from bad table.
+ */
+ *extra = 2;
+ }
+
+ if ((bb->count + (*extra)) >= MAX_BADBLOCKS)
+ return false;
+
+ return true;
+}
+
+/*
+ * Do the overwrite from the range indicated by 'bad' to the bad range
+ * (from bad table) indexed by 'prev'.
+ * The previously called can_front_overwrite() will provide how many
+ * extra bad range(s) might be split and added into the bad table. All
+ * the splitting cases in the bad table will be handled here.
+ */
+static int front_overwrite(struct badblocks *bb, int prev,
+ struct bad_context *bad, int extra)
+{
+ u64 *p = bb->page;
+ int n = extra;
+ sector_t orig_end = BB_END(p[prev]);
+ int orig_ack = BB_ACK(p[prev]);
+
+ switch (extra) {
+ case 0:
+ p[prev] = BB_MAKE(BB_OFFSET(p[prev]), BB_LEN(p[prev]),
+ bad->ack);
+ break;
+ case 1:
+ if (BB_OFFSET(p[prev]) == bad->start) {
+ p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
+ bad->len, bad->ack);
+ memmove(p + prev + 2, p + prev + 1,
+ (bb->count - prev - 1) * 8);
+ p[prev + 1] = BB_MAKE(bad->start + bad->len,
+ orig_end - BB_END(p[prev]),
+ orig_ack);
+ } else {
+ p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
+ BB_END(p[prev]) - bad->start,
+ BB_ACK(p[prev]));
+ memmove(p + prev + 1 + n, p + prev + 1,
+ (bb->count - prev - 1) * 8);
+ p[prev + 1] = BB_MAKE(bad->start, bad->len, bad->ack);
+ }
+ break;
+ case 2:
+ p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
+ BB_END(p[prev]) - bad->start,
+ BB_ACK(p[prev]));
+ memmove(p + prev + 1 + n, p + prev + 1,
+ (bb->count - prev - 1) * 8);
+ p[prev + 1] = BB_MAKE(bad->start, bad->len, bad->ack);
+ p[prev + 2] = BB_MAKE(BB_END(p[prev + 1]),
+ orig_end - BB_END(p[prev + 1]),
+ BB_ACK(p[prev]));
+ break;
+ default:
+ break;
+ }
+
+ return bad->len;
+}
+
+/*
+ * Explicitly insert a range indicated by 'bad' to the bad table, where
+ * the location is indexed by 'at'.
+ */
+static int insert_at(struct badblocks *bb, int at, struct bad_context *bad)
+{
+ u64 *p = bb->page;
+ sector_t sectors = bad->len;
+ sector_t s = bad->start;
+ int ack = bad->ack;
+ int len;
+
+ WARN_ON(badblocks_full(bb));
+
+ len = min_t(sector_t, sectors, BB_MAX_LEN);
+ if (at < bb->count)
+ memmove(p + at + 1, p + at, (bb->count - at) * 8);
+ p[at] = BB_MAKE(s, len, ack);
+
+ return len;
+}
+
/**
* badblocks_check() - check a given range for bad sectors
* @bb: the badblocks structure that holds all badblock information
--
2.26.2
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^ permalink raw reply related [flat|nested] 9+ messages in thread* [RFC PATCH v1 3/6] badblocks: improvement badblocks_set() for multiple ranges handling
2021-03-02 4:02 [RFC PATCH v1 0/6] badblocks improvement for multiple bad block ranges Coly Li
2021-03-02 4:02 ` [RFC PATCH v1 1/6] badblocks: add more helper structure and routines in badblocks.h Coly Li
2021-03-02 4:02 ` [RFC PATCH v1 2/6] badblocks: add helper routines for badblock ranges handling Coly Li
@ 2021-03-02 4:02 ` Coly Li
2021-03-02 4:02 ` [RFC PATCH v1 4/6] badblocks: improve badblocks_clear() " Coly Li
` (2 subsequent siblings)
5 siblings, 0 replies; 9+ messages in thread
From: Coly Li @ 2021-03-02 4:02 UTC (permalink / raw)
To: linux-block, axboe, dan.j.williams, vishal.l.verma, neilb
Cc: antlists, linux-kernel, linux-raid, linux-nvdimm, Coly Li
Recently I received a bug report that current badblocks code does not
properly handle multiple ranges. For example,
badblocks_set(bb, 32, 1, true);
badblocks_set(bb, 34, 1, true);
badblocks_set(bb, 36, 1, true);
badblocks_set(bb, 32, 12, true);
Then indeed badblocks_show() reports,
32 3
36 1
But the expected bad blocks table should be,
32 12
Obviously only the first 2 ranges are merged and badblocks_set() returns
and ignores the rest setting range.
This behavior is improper, if the caller of badblocks_set() wants to set
a range of blocks into bad blocks table, all of the blocks in the range
should be handled even the previous part encountering failure.
The desired way to set bad blocks range by badblocks_set() is,
- Set as many as blocks in the setting range into bad blocks table.
- Merge the bad blocks ranges and occupy as less as slots in the bad
blocks table.
- Fast.
Indeed the above proposal is complicated, especially with the following
restrictions,
- The setting bad blocks range can be ackknowledged or not acknowledged.
- The bad blocks table size is limited.
- Memory allocation should be avoided.
The basic idea of the patch is to categorize all possible bad blocks
range setting combinationsinto to much less simplified and more less
special conditions. Inside badblocks_set() there is an implicit loop
composed by jumping between labels 're_insert' and 'update_sectors'. No
matter how large the setting bad blocks range is, in every loop just a
minimized range from the head is handled by a pre-defined behavior from
one of the categorized conditions. The logic is simple and code flow is
manageable.
The different relative layout between the setting range and existing bad
block range are checked and handled (merge, combine, overwrite, insert)
by the helpers in previous patch. This patch is to make all the helpers
work together with the above idea.
This patch only has the algorithm improvement for badblocks_set(). There
are following patches contain improvement for badblocks_clear() and
badblocks_check(). But the algorithm in badblocks_set() is fundamental
and typical, other improvement in clear and check routines are based on
all the helpers and ideas in this patch.
In order to make the change to be more clear for code review, this patch
does not directly modify existing badblocks_set(), and just add a new
one named _badblocks_set(). Later patch will remove current existing
badblocks_set() code and make it as a wrapper of _badblocks_set(). So
the new added change won't be mixed with deleted code, the code review
can be easier.
Signed-off-by: Coly Li <colyli@suse.de>
---
block/badblocks.c | 561 ++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 541 insertions(+), 20 deletions(-)
diff --git a/block/badblocks.c b/block/badblocks.c
index fd76bbe7b5a2..b0a7780d75c2 100644
--- a/block/badblocks.c
+++ b/block/badblocks.c
@@ -16,6 +16,322 @@
#include <linux/types.h>
#include <linux/slab.h>
+/*
+ * The purpose of badblocks set/clear is to manage bad blocks ranges which are
+ * identified by LBA addresses.
+ *
+ * When the caller of badblocks_set() wants to set a range of bad blocks, the
+ * setting range can be acked or unacked. And the setting range may merge,
+ * overwrite, skip the overlaypped already set range, depends on who they are
+ * overlapped or adjacent, and the acknowledgment type of the ranges. It can be
+ * more complicated when the setting range covers multiple already set bad block
+ * ranges, with restritctions of maximum length of each bad range and the bad
+ * table space limitation.
+ *
+ * It is difficut and unnecessary to take care of all the possible situations,
+ * for setting a large range of bad blocks, we can handle it by dividing the
+ * large range into smaller ones when encounter overlap, max range length or
+ * bad table full conditions. Every time only a smaller piece of the bad range
+ * is handled with a limited number of conditions how it is interacted with
+ * possible overlapped or adjacent already set bad block ranges. Then the hard
+ * complicated problem can be much simpler to habndle in proper way.
+ *
+ * When setting a range of bad blocks to the bad table, the simplified situations
+ * to be considered are, (The already set bad blocks ranges are naming with
+ * prefix E, and the setting bad blocks range is naming with prefix S)
+ *
+ * 1) A setting range is not overlapped or adjacent to any other already set bad
+ * block range.
+ * +--------+
+ * | S |
+ * +--------+
+ * +-------------+ +-------------+
+ * | E1 | | E2 |
+ * +-------------+ +-------------+
+ * For this situation if the bad blocks table is not full, just allocate a
+ * free slot from the bad blocks table to mark the setting range S. The
+ * result is,
+ * +-------------+ +--------+ +-------------+
+ * | E1 | | S | | E2 |
+ * +-------------+ +--------+ +-------------+
+ * 2) A setting range starts exactly at a start LBA of an already set bad blocks
+ * range.
+ * 2.1) The setting range size < already set range size
+ * +--------+
+ * | S |
+ * +--------+
+ * +-------------+
+ * | E |
+ * +-------------+
+ * 2.1.1) If S and E are both acked or unacked range, the setting range S can
+ * be merged into existing bad range E. The result is,
+ * +-------------+
+ * | S |
+ * +-------------+
+ * 2.1.2) If S is uncked setting and E is acked, the setting will be dinied, and
+ * the result is,
+ * +-------------+
+ * | E |
+ * +-------------+
+ * 2.1.3) If S is acked setting and E is unacked, range S can overwirte on E.
+ * An extra slot from the bad blocks table will be allocated for S, and head
+ * of E will move to end of the inserted range E. The result is,
+ * +--------+----+
+ * | S | E |
+ * +--------+----+
+ * 2.2) The setting range size == already set range size
+ * 2.2.1) If S and E are both acked or unacked range, the setting range S can
+ * be merged into existing bad range E. The result is,
+ * +-------------+
+ * | S |
+ * +-------------+
+ * 2.2.2) If S is uncked setting and E is acked, the setting will be dinied, and
+ * the result is,
+ * +-------------+
+ * | E |
+ * +-------------+
+ * 2.2.3) If S is acked setting and E is unacked, range S can overwirte all of
+ bad blocks range E. The result is,
+ * +-------------+
+ * | S |
+ * +-------------+
+ * 2.3) The setting range size > already set range size
+ * +-------------------+
+ * | S |
+ * +-------------------+
+ * +-------------+
+ * | E |
+ * +-------------+
+ * For such situation, the setting range S can be treated as two parts, the
+ * first part (S1) is as same size as the already set range E, the second
+ * part (S2) is the rest of setting range.
+ * +-------------+-----+ +-------------+ +-----+
+ * | S1 | S2 | | S1 | | S2 |
+ * +-------------+-----+ ===> +-------------+ +-----+
+ * +-------------+ +-------------+
+ * | E | | E |
+ * +-------------+ +-------------+
+ * Now we only focus on how to handle the setting range S1 and already set
+ * range E, which are already explained in 1.2), for the rest S2 it will be
+ * handled later in next loop.
+ * 3) A setting range starts before the start LBA of an already set bad blocks
+ * range.
+ * +-------------+
+ * | S |
+ * +-------------+
+ * +-------------+
+ * | E |
+ * +-------------+
+ * For this situation, the setting range S can be divided into two parts, the
+ * first (S1) ends at the start LBA of already set range E, the second part
+ * (S2) starts exactly at a start LBA of the already set range E.
+ * +----+---------+ +----+ +---------+
+ * | S1 | S2 | | S1 | | S2 |
+ * +----+---------+ ===> +----+ +---------+
+ * +-------------+ +-------------+
+ * | E | | E |
+ * +-------------+ +-------------+
+ * Now only the first part S1 should be handled in this loop, which is in
+ * similar condition as 1). The rest part S2 has exact same start LBA address
+ * of the already set range E, they will be handled in next loop in one of
+ * situations in 2).
+ * 4) A setting range starts after the start LBA of an already set bad blocks
+ * range.
+ * 4.1) If the setting range S exactly matches the tail part of already set bad
+ * blocks range E, like the following chart shows,
+ * +---------+
+ * | S |
+ * +---------+
+ * +-------------+
+ * | E |
+ * +-------------+
+ * 4.1.1) If range S and E have same ackknowledg value (both acked or unacked),
+ * they will be merged into one, the result is,
+ * +-------------+
+ * | S |
+ * +-------------+
+ * 4.1.2) If range E is acked and the setting range S is unacked, the setting
+ * request of S will be rejected, the result is,
+ * +-------------+
+ * | E |
+ * +-------------+
+ * 4.1.3) If range E is unacked, and the setting range S is acked, then S may
+ * overwrite the overlapped range of E, the result is,
+ * +---+---------+
+ * | E | S |
+ * +---+---------+
+ * 4.2) If the setting range S stays in middle of an already set range E, like
+ * the following chart shows,
+ * +----+
+ * | S |
+ * +----+
+ * +--------------+
+ * | E |
+ * +--------------+
+ * 4.2.1) If range S and E have same ackknowledg value (both acked or unacked),
+ * they will be merged into one, the result is,
+ * +--------------+
+ * | S |
+ * +--------------+
+ * 4.2.2) If range E is acked and the setting range S is unacked, the setting
+ * request of S will be rejected, the result is also,
+ * +--------------+
+ * | E |
+ * +--------------+
+ * 4.2.3) If range E is unacked, and the setting range S is acked, then S will
+ * inserted into middle of E and split previous range E into twp parts (E1
+ * and E2), the result is,
+ * +----+----+----+
+ * | E1 | S | E2 |
+ * +----+----+----+
+ * 4.3) If the setting bad blocks range S is overlapped with an already set bad
+ * blocks range E. The range S starts after the start LBA of range E, and
+ * ends after the end LBA of range E, as the following chart shows,
+ * +-------------------+
+ * | S |
+ * +-------------------+
+ * +-------------+
+ * | E |
+ * +-------------+
+ * For this situation the range S can be divided into two parts, the first
+ * part (S1) ends at end range E, and the second part (S2) has rest range of
+ * origin S.
+ * +---------+---------+ +---------+ +---------+
+ * | S1 | S2 | | S1 | | S2 |
+ * +---------+---------+ ===> +---------+ +---------+
+ * +-------------+ +-------------+
+ * | E | | E |
+ * +-------------+ +-------------+
+ * Now in this loop the setting range S1 and already set range E can be
+ * handled as the situations 4), the rest range S2 will be handled in next
+ * loop and ignored in this loop.
+ * 5) A setting bad blocks range S is adjacent to one or more already set bad
+ * blocks range(s), and they are all acked or unacked range.
+ * 5.1) Front merge: If the already set bad blocks range E is before setting
+ * range S and they are adjacent,
+ * +------+
+ * | S |
+ * +------+
+ * +-------+
+ * | E |
+ * +-------+
+ * 5.1.1) When total size of range S and E <= BB_MAX_LEN, and their acknowledge
+ * values are same, the setting range S can front merges into range E. The
+ * result is,
+ * +--------------+
+ * | S |
+ * +--------------+
+ * 5.1.2) Otherwise these two ranges cannot merge, just insert the setting
+ * range S right after already set range E into the bad blocks table. The
+ * result is,
+ * +--------+------+
+ * | E | S |
+ * +--------+------+
+ * 6) Special cases which above conditions cannot handle
+ * 6.1) Multiple already set ranges may merge into less ones in a full bad table
+ * +-------------------------------------------------------+
+ * | S |
+ * +-------------------------------------------------------+
+ * |<----- BB_MAX_LEN ----->|
+ * +-----+ +-----+ +-----+
+ * | E1 | | E2 | | E3 |
+ * +-----+ +-----+ +-----+
+ * In the above example, when the bad blocks table is full, inserting the
+ * first part of setting range S will fail because no more available slot
+ * can be allocated from bad blocks table. In this situation a proper
+ * setting method should be go though all the setting bad blocks range and
+ * look for chance to merge already set ranges into less ones. When there
+ * is available slot from bad blocks table, re-try again to handle more
+ * setting bad blocks ranges as many as possible.
+ * +------------------------+
+ * | S3 |
+ * +------------------------+
+ * |<----- BB_MAX_LEN ----->|
+ * +-----+-----+-----+---+-----+--+
+ * | S1 | S2 |
+ * +-----+-----+-----+---+-----+--+
+ * The above chart shows although the first part (S3) cannot be inserted due
+ * to no-space in bad blocks table, but the following E1, E2 and E3 ranges
+ * can be merged with rest part of S into less range S1 and S2. Now there is
+ * 1 free slot in bad blocks table.
+ * +------------------------+-----+-----+-----+---+-----+--+
+ * | S3 | S1 | S2 |
+ * +------------------------+-----+-----+-----+---+-----+--+
+ * Since the bad blocks table is not full anymore, re-try again for the
+ * origin setting range S. Now the setting range S3 can be inserted into the
+ * bad blocks table with previous freed slot from multiple ranges merge.
+ * 6.2) Front merge after overwrite
+ * In the following example, in bad blocks table, E1 is an acked bad blocks
+ * range and E2 is an unacked bad blocks range, therefore they are not able
+ * to merge into a larger range. The setting bad blocks range S is acked,
+ * therefore part of E2 can be overwritten by S.
+ * +--------+
+ * | S | acknowledged
+ * +--------+ S: 1
+ * +-------+-------------+ E1: 1
+ * | E1 | E2 | E2: 0
+ * +-------+-------------+
+ * With previosu simplified routines, after overwiting part of E2 with S,
+ * the bad blocks table should be (E3 is remaining part of E2 which is not
+ * overwritten by S),
+ * acknowledged
+ * +-------+--------+----+ S: 1
+ * | E1 | S | E3 | E1: 1
+ * +-------+--------+----+ E3: 0
+ * The above result is correct but not perfect. Range E1 and S in the bad
+ * blocks table are all acked, merging them into a larger one range may
+ * occupy less bad blocks table space and make badblocks_check() faster.
+ * Therefore in such situation, after overwiting range S, the previous range
+ * E1 should be checked for possible front combination. Then the ideal
+ * result can be,
+ * +----------------+----+ acknowledged
+ * | E1 | E3 | E1: 1
+ * +----------------+----+ E3: 0
+ * 6.3) Behind merge: If the already set bad blocks range E is behind the setting
+ * range S and they are adjacent. Normally we don't need to care about this
+ * because front merge handles this while going though range S from head to
+ * tail, except for the tail part of range S. When the setting range S are
+ * fully handled, all the above simplified routine doesn't check whether the
+ * tail LBA of range S is adjacent to the next already set range and not able
+ * to them if they are mergeable.
+ * +------+
+ * | S |
+ * +------+
+ * +-------+
+ * | E |
+ * +-------+
+ * For the above special stiuation, when the setting range S are all handled
+ * and the loop ends, an extra check is necessary for whether next already
+ * set range E is right after S and mergeable.
+ * 6.2.1) When total size of range E and S <= BB_MAX_LEN, and their acknowledge
+ * values are same, the setting range S can behind merges into range E. The
+ * result is,
+ * +--------------+
+ * | S |
+ * +--------------+
+ * 6.2.2) Otherwise these two ranges cannot merge, just insert the setting range
+ * S infront of the already set range E in the bad blocks table. The result
+ * is,
+ * +------+-------+
+ * | S | E |
+ * +------+-------+
+ *
+ * All the above 5 simplified situations and 3 special cases may cover 99%+ of
+ * the bad block range setting conditions. Maybe there is some rare corner case
+ * is not considered and optimized, it won't hurt if badblocks_set() fails due
+ * to no space, or some ranges are not merged to save bad blocks table space.
+ *
+ * Inside badblocks_set() each loop starts by jumping to re_insert label, every
+ * time for the new loop prev_badblocks() is called to find an already set range
+ * which starts before or at current setting range. Since the setting bad blocks
+ * range is handled from head to tail, most of the cases it is unnecessary to do
+ * the binary search inside prev_badblocks(), it is possible to provide a hint
+ * to prev_badblocks() for a fast path, then the expensive binary search can be
+ * avoided. In my test with the hint to prev_badblocks(), except for the first
+ * loop, all rested calls to prev_badblocks() can go into the fast path and
+ * return correct bad blocks table index immediately.
+ */
+
/*
* Find the range starts at-or-before 's' from bad table. The search
* starts from index 'hint' and stops at index 'hint_end' from the bad
@@ -390,6 +706,231 @@ static int insert_at(struct badblocks *bb, int at, struct bad_context *bad)
return len;
}
+static void badblocks_update_acked(struct badblocks *bb)
+{
+ u64 *p = bb->page;
+ int i;
+ bool unacked = false;
+
+ if (!bb->unacked_exist)
+ return;
+
+ for (i = 0; i < bb->count ; i++) {
+ if (!BB_ACK(p[i])) {
+ unacked = true;
+ break;
+ }
+ }
+
+ if (!unacked)
+ bb->unacked_exist = 0;
+}
+
+/* Do exact work to set bad block range into the bad block table */
+static int _badblocks_set(struct badblocks *bb, sector_t s, int sectors,
+ int acknowledged)
+{
+ u64 *p;
+ struct bad_context bad;
+ int prev = -1, hint = -1;
+ int len = 0, added = 0;
+ int retried = 0, space_desired = 0;
+ int rv = 0;
+ unsigned long flags;
+
+ if (bb->shift < 0)
+ /* badblocks are disabled */
+ return 1;
+
+ if (sectors == 0)
+ /* Invalid sectors number */
+ return 1;
+
+ if (bb->shift) {
+ /* round the start down, and the end up */
+ sector_t next = s + sectors;
+
+ rounddown(s, bb->shift);
+ roundup(next, bb->shift);
+ sectors = next - s;
+ }
+
+ write_seqlock_irqsave(&bb->lock, flags);
+
+ bad.orig_start = s;
+ bad.orig_len = sectors;
+ bad.ack = acknowledged;
+ p = bb->page;
+
+re_insert:
+ bad.start = s;
+ bad.len = sectors;
+ len = 0;
+
+ if (badblocks_empty(bb)) {
+ len = insert_at(bb, 0, &bad);
+ bb->count++;
+ added++;
+ goto update_sectors;
+ }
+
+ prev = prev_badblocks(bb, &bad, hint);
+
+ /* start before all badblocks */
+ if (prev < 0) {
+ if (!badblocks_full(bb)) {
+ /* insert on the first */
+ if (bad.len > (BB_OFFSET(p[0]) - bad.start))
+ bad.len = BB_OFFSET(p[0]) - bad.start;
+ len = insert_at(bb, 0, &bad);
+ bb->count++;
+ added++;
+ hint = 0;
+ goto update_sectors;
+ }
+
+ /* No sapce, try to merge */
+ if (overlap_behind(bb, &bad, 0)) {
+ if (can_merge_behind(bb, &bad, 0)) {
+ len = behind_merge(bb, &bad, 0);
+ added++;
+ } else {
+ len = min_t(sector_t,
+ BB_OFFSET(p[0]) - s, sectors);
+ space_desired = 1;
+ }
+ hint = 0;
+ goto update_sectors;
+ }
+
+ /* no table space and give up */
+ goto out;
+ }
+
+ /* in case p[prev-1] can be merged with p[prev] */
+ if (can_combine_front(bb, prev, &bad)) {
+ front_combine(bb, prev);
+ bb->count--;
+ added++;
+ hint = prev - 1;
+ goto update_sectors;
+ }
+
+ if (overlap_front(bb, prev, &bad)) {
+ if (can_merge_front(bb, prev, &bad)) {
+ len = front_merge(bb, prev, &bad);
+ added++;
+ hint = prev - 1;
+ } else {
+ int extra = 0;
+
+ if (!can_front_overwrite(bb, prev, &bad, &extra)) {
+ len = min_t(sector_t,
+ BB_END(p[prev]) - s, sectors);
+ hint = prev;
+ goto update_sectors;
+ }
+
+ len = front_overwrite(bb, prev, &bad, extra);
+ added++;
+ bb->count += extra;
+ hint = prev;
+
+ if (prev > 0 && can_combine_front(bb, prev, &bad)) {
+ front_combine(bb, prev);
+ bb->count--;
+ hint = prev - 1;
+ }
+ }
+ goto update_sectors;
+ }
+
+ if (can_merge_front(bb, prev, &bad)) {
+ len = front_merge(bb, prev, &bad);
+ added++;
+ hint = prev;
+ goto update_sectors;
+ }
+
+ /* if no space in table, still try to merge in the covered range */
+ if (badblocks_full(bb)) {
+ /* skip the cannot-merge range */
+ if (((prev + 1) < bb->count) &&
+ overlap_behind(bb, &bad, prev + 1) &&
+ ((s + sectors) >= BB_END(p[prev + 1]))) {
+ len = BB_END(p[prev + 1]) - s;
+ hint = prev + 1;
+ goto update_sectors;
+ }
+
+ /* no retry any more */
+ len = sectors;
+ space_desired = 1;
+ hint = -1;
+ goto update_sectors;
+ }
+
+ /* cannot merge and there is space in bad table */
+ if ((prev + 1) < bb->count &&
+ overlap_behind(bb, &bad, prev + 1))
+ bad.len = min_t(sector_t,
+ bad.len, BB_OFFSET(p[prev + 1]) - bad.start);
+
+ len = insert_at(bb, prev + 1, &bad);
+ bb->count++;
+ added++;
+ hint = prev + 1;
+
+update_sectors:
+ s += len;
+ sectors -= len;
+
+ if (sectors > 0)
+ goto re_insert;
+
+ WARN_ON(sectors < 0);
+
+ /* Check whether the following already set range can be merged */
+ if ((prev + 1) < bb->count &&
+ BB_END(p[prev]) == BB_OFFSET(p[prev + 1]) &&
+ (BB_LEN(p[prev]) + BB_LEN(p[prev + 1])) <= BB_MAX_LEN &&
+ BB_ACK(p[prev]) == BB_ACK(p[prev + 1])) {
+ p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
+ BB_LEN(p[prev]) + BB_LEN(p[prev + 1]),
+ BB_ACK(p[prev]));
+
+ if ((prev + 2) < bb->count)
+ memmove(p + prev + 1, p + prev + 2,
+ (bb->count - (prev + 2)) * 8);
+ bb->count--;
+ }
+
+ if (space_desired && !badblocks_full(bb)) {
+ s = bad.orig_start;
+ sectors = bad.orig_len;
+ space_desired = 0;
+ if (retried++ < 3)
+ goto re_insert;
+ }
+
+out:
+ if (added) {
+ set_changed(bb);
+
+ if (!acknowledged)
+ bb->unacked_exist = 1;
+ else
+ badblocks_update_acked(bb);
+ }
+
+ write_sequnlock_irqrestore(&bb->lock, flags);
+
+ if (!added)
+ rv = 1;
+
+ return rv;
+}
+
/**
* badblocks_check() - check a given range for bad sectors
* @bb: the badblocks structure that holds all badblock information
@@ -499,26 +1040,6 @@ int badblocks_check(struct badblocks *bb, sector_t s, int sectors,
}
EXPORT_SYMBOL_GPL(badblocks_check);
-static void badblocks_update_acked(struct badblocks *bb)
-{
- u64 *p = bb->page;
- int i;
- bool unacked = false;
-
- if (!bb->unacked_exist)
- return;
-
- for (i = 0; i < bb->count ; i++) {
- if (!BB_ACK(p[i])) {
- unacked = true;
- break;
- }
- }
-
- if (!unacked)
- bb->unacked_exist = 0;
-}
-
/**
* badblocks_set() - Add a range of bad blocks to the table.
* @bb: the badblocks structure that holds all badblock information
--
2.26.2
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^ permalink raw reply related [flat|nested] 9+ messages in thread* [RFC PATCH v1 4/6] badblocks: improve badblocks_clear() for multiple ranges handling
2021-03-02 4:02 [RFC PATCH v1 0/6] badblocks improvement for multiple bad block ranges Coly Li
` (2 preceding siblings ...)
2021-03-02 4:02 ` [RFC PATCH v1 3/6] badblocks: improvement badblocks_set() for multiple " Coly Li
@ 2021-03-02 4:02 ` Coly Li
2021-03-02 4:02 ` [RFC PATCH v1 5/6] badblocks: improve badblocks_check() " Coly Li
2021-03-02 4:02 ` [RFC PATCH v1 6/6] badblocks: switch to the improved badblock handling code Coly Li
5 siblings, 0 replies; 9+ messages in thread
From: Coly Li @ 2021-03-02 4:02 UTC (permalink / raw)
To: linux-block, axboe, dan.j.williams, vishal.l.verma, neilb
Cc: antlists, linux-kernel, linux-raid, linux-nvdimm, Coly Li
With the foundamental ideas and helper routines from badblocks_set()
improvement, clearing bad block for multiple ranges is much simpler.
With a similar idea from badblocks_set() improvement, this patch
simplifies bad block range clearing into 5 situations. No matter how
complicated the clearing condition is, we just look at the head part
of clearing range with relative already set bad block range from the
bad block table. The rested part will be handled in next run of the
while-loop.
Based on existing helpers addef from badblocks_set(), this patch adds
two more helpers,
- front_clear()
Clear the bad block range from bad block table which is front
overlapped with the clearing range.
- front_splitting_clear()
Handle the condition that the clearing range hits middle of an
already set bad block range from bad block table.
Similar as badblocks_set(), the first part of clearing range is handled
with relative bad block range which is find by prev_badblocks(). In most
cases a valid hint is provided to prev_badblocks() to avoid unnecessary
bad block table iteration.
This patch also explains the detail algorithm code comments at beginning
of badblocks.c, including which five simplified situations are categried
and how all the bad block range clearing conditions are handled by these
five situations.
Again, in order to make the code review easier and avoid the code
changes mixed together, this patch does not modify badblock_clear() and
implement another routine called _badblock_clear() for the improvement.
Later patch will delete current code of badblock_clear() and make it as
a wrapper to _badblock_clear(), so the code change can be much clear for
review.
Signed-off-by: Coly Li <colyli@suse.de>
---
block/badblocks.c | 319 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 319 insertions(+)
diff --git a/block/badblocks.c b/block/badblocks.c
index b0a7780d75c2..4db6d1adff42 100644
--- a/block/badblocks.c
+++ b/block/badblocks.c
@@ -330,6 +330,123 @@
* avoided. In my test with the hint to prev_badblocks(), except for the first
* loop, all rested calls to prev_badblocks() can go into the fast path and
* return correct bad blocks table index immediately.
+ *
+ *
+ * Clearing a bad blocks range from the bad block table has similar idea as
+ * setting does, but much more simpler. The only thing needs to be noticed is
+ * when the clearning range hits middle of a bad block range, the existing bad
+ * block range will split into two, and one more item should be added into the
+ * bad block table. The simplified situations to beconsidered are, (The already
+ * set bad blocks ranges in bad block table are naming with prefix E, and the
+ * clearing bad blocks range is naming with prefix C)
+ *
+ * 1) A clearing range is not overlapped to any already set ranges in bad block
+ * table.
+ * +-----+ | +-----+ | +-----+
+ * | C | | | C | | | C |
+ * +-----+ or +-----+ or +-----+
+ * +---+ | +----+ +----+ | +---+
+ * | E | | | E1 | | E2 | | | E |
+ * +---+ | +----+ +----+ | +---+
+ * For the above situations, no bad block to be cleared and no failure
+ * happens, simply returns 0.
+ * 2) The clearing range hits middle of an already setting bad blocks range in
+ * the bad block table.
+ * +---+
+ * | C |
+ * +---+
+ * +-----------------+
+ * | E |
+ * +-----------------+
+ * In this situation if the bad block table is not full, the range E will be
+ * split into two ranges E1 and E2. The result is,
+ * +------+ +------+
+ * | E1 | | E2 |
+ * +------+ +------+
+ * 3) The clearing range starts exactly at same LBA as an already set bad block range
+ * from the bad block table.
+ * 3.1) Partially covered at head part
+ * +------------+
+ * | C |
+ * +------------+
+ * +-----------------+
+ * | E |
+ * +-----------------+
+ * For this situation, the overlapped already set range will update the
+ * start LBA to end of C and shrink the range to BB_LEN(E) - BB_LEN(C). No
+ * item deleted from bad block table. The result is,
+ * +----+
+ * | E1 |
+ * +----+
+ * 3.2) Exact fully covered
+ * +-----------------+
+ * | C |
+ * +-----------------+
+ * +-----------------+
+ * | E |
+ * +-----------------+
+ * For this situation the whole bad blocks range E will be cleared and its
+ * corresponded item is deleted from the bad block table.
+ * 4) The clearing range exactly ends at same LBA as an already set bad block
+ * range.
+ * +-------+
+ * | C |
+ * +-------+
+ * +-----------------+
+ * | E |
+ * +-----------------+
+ * For the above situation, the already set range E is updated to shrink its
+ * end to the start of C, and reduce its length to BB_LEN(E) - BB_LEN(C).
+ * The result is,
+ * +---------+
+ * | E |
+ * +---------+
+ * 5) The clearing range is partially overlapped with an already set bad block
+ * range from the bad block table.
+ * 5.1) The already set bad block range is front overlapped with the clearing
+ * range.
+ * +----------+
+ * | C |
+ * +----------+
+ * +------------+
+ * | E |
+ * +------------+
+ * For such situation, the clearing range C can be treated as two parts. The
+ * first part ends at the start LBA of range E, and the second part starts at
+ * same LBA of range E.
+ * +----+-----+ +----+ +-----+
+ * | C1 | C2 | | C1 | | C2 |
+ * +----+-----+ ===> +----+ +-----+
+ * +------------+ +------------+
+ * | E | | E |
+ * +------------+ +------------+
+ * Now the first part C1 can be handled as condition 1), and the second part C2 can be
+ * handled as condition 3.1) in next loop.
+ * 5.2) The already set bad block range is behind overlaopped with the clearing
+ * range.
+ * +----------+
+ * | C |
+ * +----------+
+ * +------------+
+ * | E |
+ * +------------+
+ * For such situation, the clearing range C can be treated as two parts. The
+ * first part C1 ends at same end LBA of range E, and the second part starts
+ * at end LBA of range E.
+ * +----+-----+ +----+ +-----+
+ * | C1 | C2 | | C1 | | C2 |
+ * +----+-----+ ===> +----+ +-----+
+ * +------------+ +------------+
+ * | E | | E |
+ * +------------+ +------------+
+ * Now the first part clearing range C1 can be handled as condition 4), and
+ * the second part clearing range C2 can be handled as condition 1) in next
+ * loop.
+ *
+ * All bad blocks range clearing can be simplified into the above 5 situations
+ * by only handling the head part of the clearing range in each run of the
+ * while-loop. The idea is similar to bad blocks range setting but much
+ * simpler.
*/
/*
@@ -931,6 +1048,208 @@ static int _badblocks_set(struct badblocks *bb, sector_t s, int sectors,
return rv;
}
+/*
+ * Clear the bad block range from bad block table which is front overlapped
+ * with the clearing range. The return value is how many sectors from an
+ * already set bad block range are cleared. If the whole bad block range is
+ * covered by the clearing range and fully cleared, 'delete' is set as 1 for
+ * the caller to reduce bb->count.
+ */
+static int front_clear(struct badblocks *bb, int prev,
+ struct bad_context *bad, int *deleted)
+{
+ sector_t sectors = bad->len;
+ sector_t s = bad->start;
+ u64 *p = bb->page;
+ int cleared = 0;
+
+ *deleted = 0;
+ if (s == BB_OFFSET(p[prev])) {
+ if (BB_LEN(p[prev]) > sectors) {
+ p[prev] = BB_MAKE(BB_OFFSET(p[prev]) + sectors,
+ BB_LEN(p[prev]) - sectors,
+ BB_ACK(p[prev]));
+ cleared = sectors;
+ } else {
+ /* BB_LEN(p[prev]) <= sectors */
+ cleared = BB_LEN(p[prev]);
+ if ((prev + 1) < bb->count)
+ memmove(p + prev, p + prev + 1,
+ (bb->count - prev - 1) * 8);
+ *deleted = 1;
+ }
+ } else if (s > BB_OFFSET(p[prev])) {
+ if (BB_END(p[prev]) <= (s + sectors)) {
+ cleared = BB_END(p[prev]) - s;
+ p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
+ s - BB_OFFSET(p[prev]),
+ BB_ACK(p[prev]));
+ } else {
+ /* Splitting is handled in front_splitting_clear() */
+ BUG();
+ }
+ }
+
+ return cleared;
+}
+
+/*
+ * Handle the condition that the clearing range hits middle of an already set
+ * bad block range from bad block table. In this condition the existing bad
+ * block range is split into two after the middle part is cleared.
+ */
+static int front_splitting_clear(struct badblocks *bb, int prev,
+ struct bad_context *bad)
+{
+ sector_t sectors = bad->len;
+ sector_t s = bad->start;
+ u64 *p = bb->page;
+ u64 end = BB_END(p[prev]);
+ int ack = BB_ACK(p[prev]);
+
+ p[prev] = BB_MAKE(BB_OFFSET(p[prev]),
+ s - BB_OFFSET(p[prev]),
+ ack);
+ memmove(p + prev + 2, p + prev + 1, (bb->count - prev - 1) * 8);
+ p[prev + 1] = BB_MAKE(s + sectors, end - s - sectors, ack);
+ return sectors;
+}
+
+/* Do the exact work to clear bad block range from the bad block table */
+static int _badblocks_clear(struct badblocks *bb, sector_t s, int sectors)
+{
+ u64 *p;
+ struct bad_context bad;
+ int prev = -1, hint = -1;
+ int len = 0, cleared = 0;
+ int rv = 0;
+
+ if (bb->shift < 0)
+ /* badblocks are disabled */
+ return 1;
+
+ if (sectors == 0)
+ /* Invalid sectors number */
+ return 1;
+
+ if (bb->shift) {
+ sector_t target;
+
+ /* When clearing we round the start up and the end down.
+ * This should not matter as the shift should align with
+ * the block size and no rounding should ever be needed.
+ * However it is better the think a block is bad when it
+ * isn't than to think a block is not bad when it is.
+ */
+ target = s + sectors;
+ roundup(s, bb->shift);
+ rounddown(target, bb->shift);
+ sectors = target - s;
+ }
+
+ write_seqlock_irq(&bb->lock);
+
+ bad.orig_start = s;
+ bad.orig_len = sectors;
+ bad.ack = true;
+ p = bb->page;
+
+re_clear:
+ bad.start = s;
+ bad.len = sectors;
+
+ if (badblocks_empty(bb)) {
+ len = sectors;
+ cleared++;
+ goto update_sectors;
+ }
+
+
+ prev = prev_badblocks(bb, &bad, hint);
+
+ /* start before all badblocks */
+ if (prev < 0) {
+ if (overlap_behind(bb, &bad, 0)) {
+ len = BB_OFFSET(p[0]) - s;
+ hint = prev;
+ } else {
+ len = sectors;
+ cleared++;
+ }
+ goto update_sectors;
+ }
+
+ /* start after all badblocks */
+ if ((prev + 1) >= bb->count && !overlap_front(bb, prev, &bad)) {
+ len = sectors;
+ cleared++;
+ goto update_sectors;
+ }
+
+ /* Clear will split a bad record but the table is full */
+ if (badblocks_full(bb) && (BB_OFFSET(p[prev]) < bad.start) &&
+ (BB_END(p[prev]) > (bad.start + sectors))) {
+ len = sectors;
+ goto update_sectors;
+ }
+
+ if (overlap_front(bb, prev, &bad)) {
+ if ((BB_OFFSET(p[prev]) < bad.start) &&
+ (BB_END(p[prev]) > (bad.start + bad.len))) {
+ /* Splitting */
+ if ((bb->count + 1) < MAX_BADBLOCKS) {
+ len = front_splitting_clear(bb, prev, &bad);
+ bb->count += 1;
+ cleared++;
+ } else {
+ /* No space to split, give up */
+ len = sectors;
+ }
+ } else {
+ int deleted = 0;
+
+ len = front_clear(bb, prev, &bad, &deleted);
+ bb->count -= deleted;
+ cleared++;
+ hint = prev;
+ }
+
+ goto update_sectors;
+ }
+
+ /* Not front overlap, but behind overlap */
+ if ((prev + 1) < bb->count && overlap_behind(bb, &bad, prev + 1)) {
+ len = BB_OFFSET(p[prev + 1]) - bad.start;
+ hint = prev + 1;
+ goto update_sectors;
+ }
+
+ /* not cover any badblocks range in the table */
+ len = sectors;
+
+update_sectors:
+ s += len;
+ sectors -= len;
+
+ if (sectors > 0)
+ goto re_clear;
+
+ WARN_ON(sectors < 0);
+
+ if (cleared) {
+ badblocks_update_acked(bb);
+ set_changed(bb);
+ }
+
+ write_sequnlock_irq(&bb->lock);
+
+ if (!cleared)
+ rv = 1;
+
+ return rv;
+}
+
+
/**
* badblocks_check() - check a given range for bad sectors
* @bb: the badblocks structure that holds all badblock information
--
2.26.2
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^ permalink raw reply related [flat|nested] 9+ messages in thread* [RFC PATCH v1 5/6] badblocks: improve badblocks_check() for multiple ranges handling
2021-03-02 4:02 [RFC PATCH v1 0/6] badblocks improvement for multiple bad block ranges Coly Li
` (3 preceding siblings ...)
2021-03-02 4:02 ` [RFC PATCH v1 4/6] badblocks: improve badblocks_clear() " Coly Li
@ 2021-03-02 4:02 ` Coly Li
2021-03-02 4:02 ` [RFC PATCH v1 6/6] badblocks: switch to the improved badblock handling code Coly Li
5 siblings, 0 replies; 9+ messages in thread
From: Coly Li @ 2021-03-02 4:02 UTC (permalink / raw)
To: linux-block, axboe, dan.j.williams, vishal.l.verma, neilb
Cc: antlists, linux-kernel, linux-raid, linux-nvdimm, Coly Li
This patch rewrites badblocks_check() with similar coding style as
_badblocks_set() and _badblocks_clear(). The only difference is bad
blocks checking may handle multiple ranges in bad tables now.
If a checking range covers multiple bad blocks range in bad block table,
like the following condition (C is the checking range, E1, E2, E3 are
three bad block ranges in bad block table),
+------------------------------------+
| C |
+------------------------------------+
+----+ +----+ +----+
| E1 | | E2 | | E3 |
+----+ +----+ +----+
The improved badblocks_check() algorithm will divid checking range C
into multiple parts, and handle them in 7 runs of a while-loop,
+--+ +----+ +----+ +----+ +----+ +----+ +----+
|C1| | C2 | | C3 | | C4 | | C5 | | C6 | | C7 |
+--+ +----+ +----+ +----+ +----+ +----+ +----+
+----+ +----+ +----+
| E1 | | E2 | | E3 |
+----+ +----+ +----+
And the start LBA and length of range E1 will be set as first_bad and
bad_sectors for the caller.
The return value rule is consistent for multiple ranges. For example if
there are following bad block ranges in bad block table,
Index No. Start Len Ack
0 400 20 1
1 500 50 1
2 650 20 0
the return value, first_bad, bad_sectors by calling badblocks_set() with
different checking range can be the following values,
Checking Start, Len Return Value first_bad bad_sectors
100, 100 0 N/A N/A
100, 310 1 400 10
100, 440 1 400 10
100, 540 1 400 10
100, 600 -1 400 10
100, 800 -1 400 10
In order to make code review easier, this patch names the improved bad
block range checking routine as _badblocks_check() and does not change
existing badblock_check() code yet. Later patch will delete old code of
badblocks_check() and make it as a wrapper to call _badblocks_check().
Then the new added code won't mess up with the old deleted code, it will
be more clear and easier for code review.
Signed-off-by: Coly Li <colyli@suse.de>
---
block/badblocks.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 99 insertions(+)
diff --git a/block/badblocks.c b/block/badblocks.c
index 4db6d1adff42..304b91159a42 100644
--- a/block/badblocks.c
+++ b/block/badblocks.c
@@ -1249,6 +1249,105 @@ static int _badblocks_clear(struct badblocks *bb, sector_t s, int sectors)
return rv;
}
+/* Do the exact work to check bad blocks range from the bad block table */
+static int _badblocks_check(struct badblocks *bb, sector_t s, int sectors,
+ sector_t *first_bad, int *bad_sectors)
+{
+ u64 *p;
+ struct bad_context bad;
+ int prev = -1, hint = -1, set = 0;
+ int unacked_badblocks, acked_badblocks;
+ int len, rv;
+ unsigned int seq;
+
+ WARN_ON(bb->shift < 0 || sectors == 0);
+
+ if (bb->shift > 0) {
+ sector_t target;
+
+ /* round the start down, and the end up */
+ target = s + sectors;
+ rounddown(s, bb->shift);
+ roundup(target, bb->shift);
+ sectors = target - s;
+ }
+
+retry:
+ seq = read_seqbegin(&bb->lock);
+
+ bad.orig_start = s;
+ bad.orig_len = sectors;
+ p = bb->page;
+ unacked_badblocks = 0;
+ acked_badblocks = 0;
+
+re_check:
+ bad.start = s;
+ bad.len = sectors;
+
+ if (badblocks_empty(bb)) {
+ len = sectors;
+ goto update_sectors;
+ }
+
+ prev = prev_badblocks(bb, &bad, hint);
+
+ /* start after all badblocks */
+ if ((prev + 1) >= bb->count && !overlap_front(bb, prev, &bad)) {
+ len = sectors;
+ goto update_sectors;
+ }
+
+ if (overlap_front(bb, prev, &bad)) {
+ if (BB_ACK(p[prev]))
+ acked_badblocks++;
+ else
+ unacked_badblocks++;
+
+ if (BB_END(p[prev]) >= (s + sectors))
+ len = sectors;
+ else
+ len = BB_END(p[prev]) - s;
+
+ if (set == 0) {
+ *first_bad = BB_OFFSET(p[prev]);
+ *bad_sectors = BB_LEN(p[prev]);
+ set = 1;
+ }
+ goto update_sectors;
+ }
+
+ /* Not front overlap, but behind overlap */
+ if ((prev + 1) < bb->count && overlap_behind(bb, &bad, prev + 1)) {
+ len = BB_OFFSET(p[prev + 1]) - bad.start;
+ hint = prev + 1;
+ goto update_sectors;
+ }
+
+ /* not cover any badblocks range in the table */
+ len = sectors;
+
+update_sectors:
+ s += len;
+ sectors -= len;
+
+ if (sectors > 0)
+ goto re_check;
+
+ WARN_ON(sectors < 0);
+
+ if (unacked_badblocks > 0)
+ rv = -1;
+ else if (acked_badblocks > 0)
+ rv = 1;
+ else
+ rv = 0;
+
+ if (read_seqretry(&bb->lock, seq))
+ goto retry;
+
+ return rv;
+}
/**
* badblocks_check() - check a given range for bad sectors
--
2.26.2
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^ permalink raw reply related [flat|nested] 9+ messages in thread* [RFC PATCH v1 6/6] badblocks: switch to the improved badblock handling code
2021-03-02 4:02 [RFC PATCH v1 0/6] badblocks improvement for multiple bad block ranges Coly Li
` (4 preceding siblings ...)
2021-03-02 4:02 ` [RFC PATCH v1 5/6] badblocks: improve badblocks_check() " Coly Li
@ 2021-03-02 4:02 ` Coly Li
5 siblings, 0 replies; 9+ messages in thread
From: Coly Li @ 2021-03-02 4:02 UTC (permalink / raw)
To: linux-block, axboe, dan.j.williams, vishal.l.verma, neilb
Cc: antlists, linux-kernel, linux-raid, linux-nvdimm, Coly Li
This patch removes old code of badblocks_set(), badblocks_clear() and
badblocks_check(), and make them as wrappers to call _badblocks_set(),
_badblocks_clear() and _badblocks_check().
By this change now the badblock handing switch to the improved algorithm
in _badblocks_set(), _badblocks_clear() and _badblocks_check().
This patch only contains the changes of old code deletion, new added
code for the improved algorithms are in previous patches.
Signed-off-by: Coly Li <colyli@suse.de>
---
block/badblocks.c | 310 +---------------------------------------------
1 file changed, 3 insertions(+), 307 deletions(-)
diff --git a/block/badblocks.c b/block/badblocks.c
index 304b91159a42..904c6ed0de6d 100644
--- a/block/badblocks.c
+++ b/block/badblocks.c
@@ -1386,75 +1386,7 @@ static int _badblocks_check(struct badblocks *bb, sector_t s, int sectors,
int badblocks_check(struct badblocks *bb, sector_t s, int sectors,
sector_t *first_bad, int *bad_sectors)
{
- int hi;
- int lo;
- u64 *p = bb->page;
- int rv;
- sector_t target = s + sectors;
- unsigned seq;
-
- if (bb->shift > 0) {
- /* round the start down, and the end up */
- s >>= bb->shift;
- target += (1<<bb->shift) - 1;
- target >>= bb->shift;
- sectors = target - s;
- }
- /* 'target' is now the first block after the bad range */
-
-retry:
- seq = read_seqbegin(&bb->lock);
- lo = 0;
- rv = 0;
- hi = bb->count;
-
- /* Binary search between lo and hi for 'target'
- * i.e. for the last range that starts before 'target'
- */
- /* INVARIANT: ranges before 'lo' and at-or-after 'hi'
- * are known not to be the last range before target.
- * VARIANT: hi-lo is the number of possible
- * ranges, and decreases until it reaches 1
- */
- while (hi - lo > 1) {
- int mid = (lo + hi) / 2;
- sector_t a = BB_OFFSET(p[mid]);
-
- if (a < target)
- /* This could still be the one, earlier ranges
- * could not.
- */
- lo = mid;
- else
- /* This and later ranges are definitely out. */
- hi = mid;
- }
- /* 'lo' might be the last that started before target, but 'hi' isn't */
- if (hi > lo) {
- /* need to check all range that end after 's' to see if
- * any are unacknowledged.
- */
- while (lo >= 0 &&
- BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) {
- if (BB_OFFSET(p[lo]) < target) {
- /* starts before the end, and finishes after
- * the start, so they must overlap
- */
- if (rv != -1 && BB_ACK(p[lo]))
- rv = 1;
- else
- rv = -1;
- *first_bad = BB_OFFSET(p[lo]);
- *bad_sectors = BB_LEN(p[lo]);
- }
- lo--;
- }
- }
-
- if (read_seqretry(&bb->lock, seq))
- goto retry;
-
- return rv;
+ return _badblocks_check(bb, s, sectors, first_bad, bad_sectors);
}
EXPORT_SYMBOL_GPL(badblocks_check);
@@ -1476,154 +1408,7 @@ EXPORT_SYMBOL_GPL(badblocks_check);
int badblocks_set(struct badblocks *bb, sector_t s, int sectors,
int acknowledged)
{
- u64 *p;
- int lo, hi;
- int rv = 0;
- unsigned long flags;
-
- if (bb->shift < 0)
- /* badblocks are disabled */
- return 1;
-
- if (bb->shift) {
- /* round the start down, and the end up */
- sector_t next = s + sectors;
-
- s >>= bb->shift;
- next += (1<<bb->shift) - 1;
- next >>= bb->shift;
- sectors = next - s;
- }
-
- write_seqlock_irqsave(&bb->lock, flags);
-
- p = bb->page;
- lo = 0;
- hi = bb->count;
- /* Find the last range that starts at-or-before 's' */
- while (hi - lo > 1) {
- int mid = (lo + hi) / 2;
- sector_t a = BB_OFFSET(p[mid]);
-
- if (a <= s)
- lo = mid;
- else
- hi = mid;
- }
- if (hi > lo && BB_OFFSET(p[lo]) > s)
- hi = lo;
-
- if (hi > lo) {
- /* we found a range that might merge with the start
- * of our new range
- */
- sector_t a = BB_OFFSET(p[lo]);
- sector_t e = a + BB_LEN(p[lo]);
- int ack = BB_ACK(p[lo]);
-
- if (e >= s) {
- /* Yes, we can merge with a previous range */
- if (s == a && s + sectors >= e)
- /* new range covers old */
- ack = acknowledged;
- else
- ack = ack && acknowledged;
-
- if (e < s + sectors)
- e = s + sectors;
- if (e - a <= BB_MAX_LEN) {
- p[lo] = BB_MAKE(a, e-a, ack);
- s = e;
- } else {
- /* does not all fit in one range,
- * make p[lo] maximal
- */
- if (BB_LEN(p[lo]) != BB_MAX_LEN)
- p[lo] = BB_MAKE(a, BB_MAX_LEN, ack);
- s = a + BB_MAX_LEN;
- }
- sectors = e - s;
- }
- }
- if (sectors && hi < bb->count) {
- /* 'hi' points to the first range that starts after 's'.
- * Maybe we can merge with the start of that range
- */
- sector_t a = BB_OFFSET(p[hi]);
- sector_t e = a + BB_LEN(p[hi]);
- int ack = BB_ACK(p[hi]);
-
- if (a <= s + sectors) {
- /* merging is possible */
- if (e <= s + sectors) {
- /* full overlap */
- e = s + sectors;
- ack = acknowledged;
- } else
- ack = ack && acknowledged;
-
- a = s;
- if (e - a <= BB_MAX_LEN) {
- p[hi] = BB_MAKE(a, e-a, ack);
- s = e;
- } else {
- p[hi] = BB_MAKE(a, BB_MAX_LEN, ack);
- s = a + BB_MAX_LEN;
- }
- sectors = e - s;
- lo = hi;
- hi++;
- }
- }
- if (sectors == 0 && hi < bb->count) {
- /* we might be able to combine lo and hi */
- /* Note: 's' is at the end of 'lo' */
- sector_t a = BB_OFFSET(p[hi]);
- int lolen = BB_LEN(p[lo]);
- int hilen = BB_LEN(p[hi]);
- int newlen = lolen + hilen - (s - a);
-
- if (s >= a && newlen < BB_MAX_LEN) {
- /* yes, we can combine them */
- int ack = BB_ACK(p[lo]) && BB_ACK(p[hi]);
-
- p[lo] = BB_MAKE(BB_OFFSET(p[lo]), newlen, ack);
- memmove(p + hi, p + hi + 1,
- (bb->count - hi - 1) * 8);
- bb->count--;
- }
- }
- while (sectors) {
- /* didn't merge (it all).
- * Need to add a range just before 'hi'
- */
- if (bb->count >= MAX_BADBLOCKS) {
- /* No room for more */
- rv = 1;
- break;
- } else {
- int this_sectors = sectors;
-
- memmove(p + hi + 1, p + hi,
- (bb->count - hi) * 8);
- bb->count++;
-
- if (this_sectors > BB_MAX_LEN)
- this_sectors = BB_MAX_LEN;
- p[hi] = BB_MAKE(s, this_sectors, acknowledged);
- sectors -= this_sectors;
- s += this_sectors;
- }
- }
-
- bb->changed = 1;
- if (!acknowledged)
- bb->unacked_exist = 1;
- else
- badblocks_update_acked(bb);
- write_sequnlock_irqrestore(&bb->lock, flags);
-
- return rv;
+ return _badblocks_set(bb, s, sectors, acknowledged);
}
EXPORT_SYMBOL_GPL(badblocks_set);
@@ -1643,96 +1428,7 @@ EXPORT_SYMBOL_GPL(badblocks_set);
*/
int badblocks_clear(struct badblocks *bb, sector_t s, int sectors)
{
- u64 *p;
- int lo, hi;
- sector_t target = s + sectors;
- int rv = 0;
-
- if (bb->shift > 0) {
- /* When clearing we round the start up and the end down.
- * This should not matter as the shift should align with
- * the block size and no rounding should ever be needed.
- * However it is better the think a block is bad when it
- * isn't than to think a block is not bad when it is.
- */
- s += (1<<bb->shift) - 1;
- s >>= bb->shift;
- target >>= bb->shift;
- sectors = target - s;
- }
-
- write_seqlock_irq(&bb->lock);
-
- p = bb->page;
- lo = 0;
- hi = bb->count;
- /* Find the last range that starts before 'target' */
- while (hi - lo > 1) {
- int mid = (lo + hi) / 2;
- sector_t a = BB_OFFSET(p[mid]);
-
- if (a < target)
- lo = mid;
- else
- hi = mid;
- }
- if (hi > lo) {
- /* p[lo] is the last range that could overlap the
- * current range. Earlier ranges could also overlap,
- * but only this one can overlap the end of the range.
- */
- if ((BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > target) &&
- (BB_OFFSET(p[lo]) < target)) {
- /* Partial overlap, leave the tail of this range */
- int ack = BB_ACK(p[lo]);
- sector_t a = BB_OFFSET(p[lo]);
- sector_t end = a + BB_LEN(p[lo]);
-
- if (a < s) {
- /* we need to split this range */
- if (bb->count >= MAX_BADBLOCKS) {
- rv = -ENOSPC;
- goto out;
- }
- memmove(p+lo+1, p+lo, (bb->count - lo) * 8);
- bb->count++;
- p[lo] = BB_MAKE(a, s-a, ack);
- lo++;
- }
- p[lo] = BB_MAKE(target, end - target, ack);
- /* there is no longer an overlap */
- hi = lo;
- lo--;
- }
- while (lo >= 0 &&
- (BB_OFFSET(p[lo]) + BB_LEN(p[lo]) > s) &&
- (BB_OFFSET(p[lo]) < target)) {
- /* This range does overlap */
- if (BB_OFFSET(p[lo]) < s) {
- /* Keep the early parts of this range. */
- int ack = BB_ACK(p[lo]);
- sector_t start = BB_OFFSET(p[lo]);
-
- p[lo] = BB_MAKE(start, s - start, ack);
- /* now low doesn't overlap, so.. */
- break;
- }
- lo--;
- }
- /* 'lo' is strictly before, 'hi' is strictly after,
- * anything between needs to be discarded
- */
- if (hi - lo > 1) {
- memmove(p+lo+1, p+hi, (bb->count - hi) * 8);
- bb->count -= (hi - lo - 1);
- }
- }
-
- badblocks_update_acked(bb);
- bb->changed = 1;
-out:
- write_sequnlock_irq(&bb->lock);
- return rv;
+ return _badblocks_clear(bb, s, sectors);
}
EXPORT_SYMBOL_GPL(badblocks_clear);
--
2.26.2
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