linux

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bcachefs: alloc_background_format.h Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> 2024-01-21 00:01:52 -05:00



























































bcachefs: Fix reuse of bucket before journal flush on multiple empty -> nonempty transition For each bucket we track when the bucket became nonempty and when it became empty again: if we can ensure that there will be no journal flushes in the range [nonempty, empty) (possibly because they occured at the same journal sequence number), then it's safe to reuse the bucket without waiting for a journal commit. This is a major performance optimization for erasure coding, where writes are initially replicated, but the extra replicas are quickly dropped: if those buckets are reused and overwritten without issuing a cache flush to the underlying device, then they only cost bus bandwidth. But there's a tricky corner case when there's multiple empty -> nonempty -> empty transitions in quick succession, i.e. when data is getting overwritten immediately as it's being written. If this happens and the previous empty transition hasn't been flushed, we need to continue tracking the previous nonempty transition - not start a new one. Fixing this means we now need to track both the nonempty and empty transitions in bch_alloc_v4. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> 2024-12-06 23:15:05 -05:00
bcachefs: alloc_background_format.h Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> 2024-01-21 00:01:52 -05:00









bcachefs: Fix compat issue with old alloc_v4 keys we allow new fields to be added to existing key types, and new versions should treat them as being zeroed; this was not handled in alloc_v4_validate. Reported-by: syzbot+3b2968fa4953885dd66a@syzkaller.appspotmail.com Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> 2024-08-21 22:57:56 -04:00
bcachefs: Fix reuse of bucket before journal flush on multiple empty -> nonempty transition For each bucket we track when the bucket became nonempty and when it became empty again: if we can ensure that there will be no journal flushes in the range [nonempty, empty) (possibly because they occured at the same journal sequence number), then it's safe to reuse the bucket without waiting for a journal commit. This is a major performance optimization for erasure coding, where writes are initially replicated, but the extra replicas are quickly dropped: if those buckets are reused and overwritten without issuing a cache flush to the underlying device, then they only cost bus bandwidth. But there's a tricky corner case when there's multiple empty -> nonempty -> empty transitions in quick succession, i.e. when data is getting overwritten immediately as it's being written. If this happens and the previous empty transition hasn't been flushed, we need to continue tracking the previous nonempty transition - not start a new one. Fixing this means we now need to track both the nonempty and empty transitions in bch_alloc_v4. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> 2024-12-06 23:15:05 -05:00
bcachefs: bch_alloc->stripe_sectors Add a separate counter to bch_alloc_v4 for amount of striped data; this lets us separately track striped and unstriped data in a bucket, which lets us see when erasure coding has failed to update extents with stripe pointers, and also find buckets to continue updating if we crash mid way through creating a new stripe. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> 2023-11-23 17:21:23 -05:00

bcachefs: alloc_background_format.h Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev> 2024-01-21 00:01:52 -05:00

95 lines 2.3 KiB Raw Normal View History

95 lines

2.3 KiB

Raw Normal View History