| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Bad block management |
| * |
| * - Heavily based on MD badblocks code from Neil Brown |
| * |
| * Copyright (c) 2015, Intel Corporation. |
| */ |
| |
| #include <linux/badblocks.h> |
| #include <linux/seqlock.h> |
| #include <linux/device.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/stddef.h> |
| #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 overlapped 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 restrictions of maximum length of each bad range and the bad |
| * table space limitation. |
| * |
| * It is difficult 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 handle 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 unacked setting and E is acked, the setting will be denied, and |
| * the result is, |
| * +-------------+ |
| * | E | |
| * +-------------+ |
| * 2.1.3) If S is acked setting and E is unacked, range S can overwrite 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 S. 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 unacked setting and E is acked, the setting will be denied, and |
| * the result is, |
| * +-------------+ |
| * | E | |
| * +-------------+ |
| * 2.2.3) If S is acked setting and E is unacked, range S can overwrite 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 2.2), 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 acknowledge 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 acknowledge 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 two 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 4.1), 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 previous simplified routines, after overwriting 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 overwriting 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 |
| * merge them even it is possible. |
| * +------+ |
| * | S | |
| * +------+ |
| * +-------+ |
| * | E | |
| * +-------+ |
| * For the above special situation, 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. |
| * 6.3.1) 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 | |
| * +--------------+ |
| * 6.3.2) Otherwise these two ranges cannot merge, just insert the setting range |
| * S in front 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. |
| * |
| * |
| * 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 clearing 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 be considered 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. |
| */ |
| |
| /* |
| * 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) |
| { |
| int hint_end = hint + 2; |
| u64 *p = bb->page; |
| int ret = -1; |
| |
| 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 badblocks_context *bad, |
| int hint) |
| { |
| sector_t s = bad->start; |
| int ret = -1; |
| int lo, hi; |
| u64 *p; |
| |
| 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; |
| |
| /* The following bisect search might be unnecessary */ |
| if (BB_OFFSET(p[lo]) > s) |
| return -1; |
| if (BB_OFFSET(p[hi - 1]) <= s) |
| return hi - 1; |
| |
| /* Do bisect search in bad table */ |
| while (hi - lo > 1) { |
| int mid = (lo + hi)/2; |
| sector_t a = BB_OFFSET(p[mid]); |
| |
| if (a == s) { |
| ret = mid; |
| goto out; |
| } |
| |
| 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 badblocks_context *bad, int behind) |
| { |
| sector_t sectors = bad->len; |
| sector_t s = bad->start; |
| u64 *p = bb->page; |
| |
| if ((s < BB_OFFSET(p[behind])) && |
| ((s + sectors) >= BB_OFFSET(p[behind])) && |
| ((BB_END(p[behind]) - s) <= BB_MAX_LEN) && |
| BB_ACK(p[behind]) == bad->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 badblocks_context *bad, |
| int behind) |
| { |
| sector_t sectors = bad->len; |
| sector_t s = bad->start; |
| u64 *p = bb->page; |
| int merged = 0; |
| |
| WARN_ON(s >= BB_OFFSET(p[behind])); |
| WARN_ON((s + sectors) < BB_OFFSET(p[behind])); |
| |
| if (s < BB_OFFSET(p[behind])) { |
| merged = BB_OFFSET(p[behind]) - s; |
| p[behind] = BB_MAKE(s, BB_LEN(p[behind]) + merged, bad->ack); |
| |
| WARN_ON((BB_LEN(p[behind]) + merged) >= BB_MAX_LEN); |
| } |
| |
| 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 badblocks_context *bad) |
| { |
| sector_t s = bad->start; |
| u64 *p = bb->page; |
| |
| if (BB_ACK(p[prev]) == bad->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 badblocks_context *bad) |
| { |
| sector_t sectors = bad->len; |
| sector_t s = bad->start; |
| 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, bad->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 badblocks_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'. |
| * The caller of front_combine() will decrease bb->count, therefore |
| * it is unnecessary to clear p[perv] after front merge. |
| */ |
| 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 badblocks_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 badblocks_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 badblocks_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 badblocks_context *bad, int extra) |
| { |
| u64 *p = bb->page; |
| 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]), |
| bad->start - BB_OFFSET(p[prev]), |
| orig_ack); |
| /* |
| * prev +2 -> prev + 1 + 1, which is for, |
| * 1) prev + 1: the slot index of the previous one |
| * 2) + 1: one more slot for extra being 1. |
| */ |
| memmove(p + prev + 2, 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]), |
| bad->start - BB_OFFSET(p[prev]), |
| orig_ack); |
| /* |
| * prev + 3 -> prev + 1 + 2, which is for, |
| * 1) prev + 1: the slot index of the previous one |
| * 2) + 2: two more slots for extra being 2. |
| */ |
| memmove(p + prev + 3, 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]), |
| orig_ack); |
| 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 badblocks_context *bad) |
| { |
| u64 *p = bb->page; |
| int len; |
| |
| WARN_ON(badblocks_full(bb)); |
| |
| len = min_t(sector_t, bad->len, BB_MAX_LEN); |
| if (at < bb->count) |
| memmove(p + at + 1, p + at, (bb->count - at) * 8); |
| p[at] = BB_MAKE(bad->start, len, bad->ack); |
| |
| return len; |
| } |
| |
| static void badblocks_update_acked(struct badblocks *bb) |
| { |
| bool unacked = false; |
| u64 *p = bb->page; |
| int i; |
| |
| 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) |
| { |
| int retried = 0, space_desired = 0; |
| int orig_len, len = 0, added = 0; |
| struct badblocks_context bad; |
| int prev = -1, hint = -1; |
| sector_t orig_start; |
| unsigned long flags; |
| int rv = 0; |
| u64 *p; |
| |
| 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); |
| |
| orig_start = s; |
| 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 = BB_OFFSET(p[0]) - s; |
| 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; |
| goto update_sectors; |
| } |
| |
| if (overlap_front(bb, prev, &bad)) { |
| if (can_merge_front(bb, prev, &bad)) { |
| len = front_merge(bb, prev, &bad); |
| added++; |
| } 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; |
| |
| if (can_combine_front(bb, prev, &bad)) { |
| front_combine(bb, prev); |
| bb->count--; |
| } |
| } |
| hint = prev; |
| 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. (prev < 0) condition is not handled here, |
| * because it's already complicated enough. |
| */ |
| if (prev >= 0 && |
| (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 = orig_start; |
| sectors = 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; |
| } |
| |
| /* |
| * 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 badblocks_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 badblocks_context *bad) |
| { |
| u64 *p = bb->page; |
| u64 end = BB_END(p[prev]); |
| int ack = BB_ACK(p[prev]); |
| sector_t sectors = bad->len; |
| sector_t s = bad->start; |
| |
| 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) |
| { |
| struct badblocks_context bad; |
| int prev = -1, hint = -1; |
| int len = 0, cleared = 0; |
| int rv = 0; |
| u64 *p; |
| |
| 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.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 = 0; |
| } else { |
| len = sectors; |
| } |
| /* |
| * Both situations are to clear non-bad range, |
| * should be treated as successful |
| */ |
| 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; |
| /* Clear non-bad range should be treated as successful */ |
| cleared++; |
| goto update_sectors; |
| } |
| |
| /* Not cover any badblocks range in the table */ |
| len = sectors; |
| /* Clear non-bad range should be treated as successful */ |
| cleared++; |
| |
| 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; |
| } |
| |
| /* 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) |
| { |
| int unacked_badblocks, acked_badblocks; |
| int prev = -1, hint = -1, set = 0; |
| struct badblocks_context bad; |
| unsigned int seq; |
| int len, rv; |
| u64 *p; |
| |
| 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); |
| |
| 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 >= 0) && |
| ((prev + 1) >= bb->count) && !overlap_front(bb, prev, &bad)) { |
| len = sectors; |
| goto update_sectors; |
| } |
| |
| /* Overlapped with front badblocks record */ |
| if ((prev >= 0) && 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 |
| * @bb: the badblocks structure that holds all badblock information |
| * @s: sector (start) at which to check for badblocks |
| * @sectors: number of sectors to check for badblocks |
| * @first_bad: pointer to store location of the first badblock |
| * @bad_sectors: pointer to store number of badblocks after @first_bad |
| * |
| * We can record which blocks on each device are 'bad' and so just |
| * fail those blocks, or that stripe, rather than the whole device. |
| * Entries in the bad-block table are 64bits wide. This comprises: |
| * Length of bad-range, in sectors: 0-511 for lengths 1-512 |
| * Start of bad-range, sector offset, 54 bits (allows 8 exbibytes) |
| * A 'shift' can be set so that larger blocks are tracked and |
| * consequently larger devices can be covered. |
| * 'Acknowledged' flag - 1 bit. - the most significant bit. |
| * |
| * Locking of the bad-block table uses a seqlock so badblocks_check |
| * might need to retry if it is very unlucky. |
| * We will sometimes want to check for bad blocks in a bi_end_io function, |
| * so we use the write_seqlock_irq variant. |
| * |
| * When looking for a bad block we specify a range and want to |
| * know if any block in the range is bad. So we binary-search |
| * to the last range that starts at-or-before the given endpoint, |
| * (or "before the sector after the target range") |
| * then see if it ends after the given start. |
| * |
| * Return: |
| * 0: there are no known bad blocks in the range |
| * 1: there are known bad block which are all acknowledged |
| * -1: there are bad blocks which have not yet been acknowledged in metadata. |
| * plus the start/length of the first bad section we overlap. |
| */ |
| int badblocks_check(struct badblocks *bb, sector_t s, int sectors, |
| sector_t *first_bad, int *bad_sectors) |
| { |
| return _badblocks_check(bb, s, sectors, first_bad, bad_sectors); |
| } |
| EXPORT_SYMBOL_GPL(badblocks_check); |
| |
| /** |
| * badblocks_set() - Add a range of bad blocks to the table. |
| * @bb: the badblocks structure that holds all badblock information |
| * @s: first sector to mark as bad |
| * @sectors: number of sectors to mark as bad |
| * @acknowledged: weather to mark the bad sectors as acknowledged |
| * |
| * This might extend the table, or might contract it if two adjacent ranges |
| * can be merged. We binary-search to find the 'insertion' point, then |
| * decide how best to handle it. |
| * |
| * Return: |
| * 0: success |
| * 1: failed to set badblocks (out of space) |
| */ |
| int badblocks_set(struct badblocks *bb, sector_t s, int sectors, |
| int acknowledged) |
| { |
| return _badblocks_set(bb, s, sectors, acknowledged); |
| } |
| EXPORT_SYMBOL_GPL(badblocks_set); |
| |
| /** |
| * badblocks_clear() - Remove a range of bad blocks to the table. |
| * @bb: the badblocks structure that holds all badblock information |
| * @s: first sector to mark as bad |
| * @sectors: number of sectors to mark as bad |
| * |
| * This may involve extending the table if we spilt a region, |
| * but it must not fail. So if the table becomes full, we just |
| * drop the remove request. |
| * |
| * Return: |
| * 0: success |
| * 1: failed to clear badblocks |
| */ |
| int badblocks_clear(struct badblocks *bb, sector_t s, int sectors) |
| { |
| return _badblocks_clear(bb, s, sectors); |
| } |
| EXPORT_SYMBOL_GPL(badblocks_clear); |
| |
| /** |
| * ack_all_badblocks() - Acknowledge all bad blocks in a list. |
| * @bb: the badblocks structure that holds all badblock information |
| * |
| * This only succeeds if ->changed is clear. It is used by |
| * in-kernel metadata updates |
| */ |
| void ack_all_badblocks(struct badblocks *bb) |
| { |
| if (bb->page == NULL || bb->changed) |
| /* no point even trying */ |
| return; |
| write_seqlock_irq(&bb->lock); |
| |
| if (bb->changed == 0 && bb->unacked_exist) { |
| u64 *p = bb->page; |
| int i; |
| |
| for (i = 0; i < bb->count ; i++) { |
| if (!BB_ACK(p[i])) { |
| sector_t start = BB_OFFSET(p[i]); |
| int len = BB_LEN(p[i]); |
| |
| p[i] = BB_MAKE(start, len, 1); |
| } |
| } |
| bb->unacked_exist = 0; |
| } |
| write_sequnlock_irq(&bb->lock); |
| } |
| EXPORT_SYMBOL_GPL(ack_all_badblocks); |
| |
| /** |
| * badblocks_show() - sysfs access to bad-blocks list |
| * @bb: the badblocks structure that holds all badblock information |
| * @page: buffer received from sysfs |
| * @unack: weather to show unacknowledged badblocks |
| * |
| * Return: |
| * Length of returned data |
| */ |
| ssize_t badblocks_show(struct badblocks *bb, char *page, int unack) |
| { |
| size_t len; |
| int i; |
| u64 *p = bb->page; |
| unsigned seq; |
| |
| if (bb->shift < 0) |
| return 0; |
| |
| retry: |
| seq = read_seqbegin(&bb->lock); |
| |
| len = 0; |
| i = 0; |
| |
| while (len < PAGE_SIZE && i < bb->count) { |
| sector_t s = BB_OFFSET(p[i]); |
| unsigned int length = BB_LEN(p[i]); |
| int ack = BB_ACK(p[i]); |
| |
| i++; |
| |
| if (unack && ack) |
| continue; |
| |
| len += snprintf(page+len, PAGE_SIZE-len, "%llu %u\n", |
| (unsigned long long)s << bb->shift, |
| length << bb->shift); |
| } |
| if (unack && len == 0) |
| bb->unacked_exist = 0; |
| |
| if (read_seqretry(&bb->lock, seq)) |
| goto retry; |
| |
| return len; |
| } |
| EXPORT_SYMBOL_GPL(badblocks_show); |
| |
| /** |
| * badblocks_store() - sysfs access to bad-blocks list |
| * @bb: the badblocks structure that holds all badblock information |
| * @page: buffer received from sysfs |
| * @len: length of data received from sysfs |
| * @unack: weather to show unacknowledged badblocks |
| * |
| * Return: |
| * Length of the buffer processed or -ve error. |
| */ |
| ssize_t badblocks_store(struct badblocks *bb, const char *page, size_t len, |
| int unack) |
| { |
| unsigned long long sector; |
| int length; |
| char newline; |
| |
| switch (sscanf(page, "%llu %d%c", §or, &length, &newline)) { |
| case 3: |
| if (newline != '\n') |
| return -EINVAL; |
| fallthrough; |
| case 2: |
| if (length <= 0) |
| return -EINVAL; |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| if (badblocks_set(bb, sector, length, !unack)) |
| return -ENOSPC; |
| else |
| return len; |
| } |
| EXPORT_SYMBOL_GPL(badblocks_store); |
| |
| static int __badblocks_init(struct device *dev, struct badblocks *bb, |
| int enable) |
| { |
| bb->dev = dev; |
| bb->count = 0; |
| if (enable) |
| bb->shift = 0; |
| else |
| bb->shift = -1; |
| if (dev) |
| bb->page = devm_kzalloc(dev, PAGE_SIZE, GFP_KERNEL); |
| else |
| bb->page = kzalloc(PAGE_SIZE, GFP_KERNEL); |
| if (!bb->page) { |
| bb->shift = -1; |
| return -ENOMEM; |
| } |
| seqlock_init(&bb->lock); |
| |
| return 0; |
| } |
| |
| /** |
| * badblocks_init() - initialize the badblocks structure |
| * @bb: the badblocks structure that holds all badblock information |
| * @enable: weather to enable badblocks accounting |
| * |
| * Return: |
| * 0: success |
| * -ve errno: on error |
| */ |
| int badblocks_init(struct badblocks *bb, int enable) |
| { |
| return __badblocks_init(NULL, bb, enable); |
| } |
| EXPORT_SYMBOL_GPL(badblocks_init); |
| |
| int devm_init_badblocks(struct device *dev, struct badblocks *bb) |
| { |
| if (!bb) |
| return -EINVAL; |
| return __badblocks_init(dev, bb, 1); |
| } |
| EXPORT_SYMBOL_GPL(devm_init_badblocks); |
| |
| /** |
| * badblocks_exit() - free the badblocks structure |
| * @bb: the badblocks structure that holds all badblock information |
| */ |
| void badblocks_exit(struct badblocks *bb) |
| { |
| if (!bb) |
| return; |
| if (bb->dev) |
| devm_kfree(bb->dev, bb->page); |
| else |
| kfree(bb->page); |
| bb->page = NULL; |
| } |
| EXPORT_SYMBOL_GPL(badblocks_exit); |
