| Message ID | 20220721121152.4180-6-colyli@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | badblocks improvement for multiple bad block ranges | expand |
On Thu, Jul 21, 2022 at 8:12 PM Coly Li <colyli@suse.de> wrote: > > 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 divide 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 The question here is that what's the usage of the return value? Now the callers only check if the return value is 0 or not. > > 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> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Geliang Tang <geliang.tang@suse.com> > Cc: Hannes Reinecke <hare@suse.de> > Cc: Jens Axboe <axboe@kernel.dk> > Cc: NeilBrown <neilb@suse.de> > Cc: Vishal L Verma <vishal.l.verma@intel.com> > Cc: Xiao Ni <xni@redhat.com> > --- > block/badblocks.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 97 insertions(+) > > diff --git a/block/badblocks.c b/block/badblocks.c > index d3fa53594aa7..cbc79f056f74 100644 > --- a/block/badblocks.c > +++ b/block/badblocks.c > @@ -1261,6 +1261,103 @@ 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) > +{ > + 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 + 1) >= bb->count && !overlap_front(bb, prev, &bad)) { > + len = sectors; > + goto update_sectors; > + } It's same with patch 4 here about !overlap_front > + It doesn't check prev<0 situation here. Is it right? The prev can be -1 here. overlap_front will check p[-1]. > + 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; > + } same with patch 4 here Regards Xiao > + > + /* 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 > -- > 2.35.3 >
diff --git a/block/badblocks.c b/block/badblocks.c index d3fa53594aa7..cbc79f056f74 100644 --- a/block/badblocks.c +++ b/block/badblocks.c @@ -1261,6 +1261,103 @@ 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) +{ + 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 + 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
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 divide 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> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Geliang Tang <geliang.tang@suse.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: NeilBrown <neilb@suse.de> Cc: Vishal L Verma <vishal.l.verma@intel.com> Cc: Xiao Ni <xni@redhat.com> --- block/badblocks.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+)