If promote target isn't set, rebalance should still leave a cached copy on the faster device. Fall back to foreground_target if it's set, or allow a cached copy on any device if neither are set. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
extent poisoning is partly so that we don't keep spewing the dmesg log when we've got unreadable data - we don't want to print these. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
syzbot discovered that this one is possible: we have pointers, but none of them are to valid devices. Reported-by: syzbot+336a6e6a2dbb7d4dba9a@syzkaller.appspotmail.com Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We store to all fields, so the kmsan warnings were spurious - but initializing via stores to bitfields appear to have been giving the compiler/kmsan trouble, and they're not necessary. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
It's possible for checksum errors to be transient - e.g. flakey controller or cable, thus we need additional retries (besides retrying from different replicas) before we can definitely return an error. This is particularly important for the next patch, which will allow the data move path to move extents with checksum errors - we don't want to accidentally introduce bitrot due to a transient error! - bch2_bkey_pick_read_device() is substantially reworked, and bch2_dev_io_failures is expanded to record more information about the type of failure (i.e. number of checksum errors). It now returns an error code that describes more precisely the reason for the failure - checksum error, io error, or offline device, instead of the previous generic "insufficient devices". This is important for the next patches that add poisoning, as we only want to poison extents when we've got real checksum errors (or perhaps IO errors?) - not because a device was offline. - Add a new option and superblock field for the number of checksum retries. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Previously, we woudn't try to read at all from a failed device - that doesn't make much sense, the device may be unhealthy (perhaps taking longer than it should to service reads), but if it's our only option we should still try to read from it. Now, bch2_bkey_pick_read_device() will pick failed devices only if there are no non-failed replicas to read from. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This implements a new extent field bitflags that apply to the whole extent. There's been a couple things we've wanted this for in the past, but the immediate need is extent poisoning, to solve a rebalance issue. Unknown extent fields can't be parsed (we won't known their size, so we can't advance to the next field), so this is an incompat feature, and using it prevents the filesystem from being mounted by old versions. This also adds the BCH_EXTENT_poisoned flag; this indicates that the data is known to be bad (i.e. there was a checksum error, and we had to write a new checksum) and reads will return errors. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
To be used for scrub, where we want the read to come from a specific device. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
steal the (clever) algorithm from get_random_u32_below() this fixes a bug where we were passing roundup_pow_of_two() a 64 bit number - we're squaring device latencies now: [ +1.681698] ------------[ cut here ]------------ [ +0.000010] UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13 [ +0.000011] shift exponent 64 is too large for 64-bit type 'long unsigned int' [ +0.000011] CPU: 1 UID: 0 PID: 196 Comm: kworker/u32:13 Not tainted 6.14.0-rc6-dave+ #10 [ +0.000012] Hardware name: ASUS System Product Name/PRIME B460I-PLUS, BIOS 1301 07/13/2021 [ +0.000005] Workqueue: events_unbound __bch2_read_endio [bcachefs] [ +0.000354] Call Trace: [ +0.000005] <TASK> [ +0.000007] dump_stack_lvl+0x5d/0x80 [ +0.000018] ubsan_epilogue+0x5/0x30 [ +0.000008] __ubsan_handle_shift_out_of_bounds.cold+0x61/0xe6 [ +0.000011] bch2_rand_range.cold+0x17/0x20 [bcachefs] [ +0.000231] bch2_bkey_pick_read_device+0x547/0x920 [bcachefs] [ +0.000229] __bch2_read_extent+0x1e4/0x18e0 [bcachefs] [ +0.000241] ? bch2_btree_iter_peek_slot+0x3df/0x800 [bcachefs] [ +0.000180] ? bch2_read_retry_nodecode+0x270/0x330 [bcachefs] [ +0.000230] bch2_read_retry_nodecode+0x270/0x330 [bcachefs] [ +0.000230] bch2_rbio_retry+0x1fa/0x600 [bcachefs] [ +0.000224] ? bch2_printbuf_make_room+0x71/0xb0 [bcachefs] [ +0.000243] ? bch2_read_csum_err+0x4a4/0x610 [bcachefs] [ +0.000278] bch2_read_csum_err+0x4a4/0x610 [bcachefs] [ +0.000227] ? __bch2_read_endio+0x58b/0x870 [bcachefs] [ +0.000220] __bch2_read_endio+0x58b/0x870 [bcachefs] [ +0.000268] ? try_to_wake_up+0x31c/0x7f0 [ +0.000011] ? process_one_work+0x176/0x330 [ +0.000008] process_one_work+0x176/0x330 [ +0.000008] worker_thread+0x252/0x390 [ +0.000008] ? __pfx_worker_thread+0x10/0x10 [ +0.000006] kthread+0xec/0x230 [ +0.000011] ? __pfx_kthread+0x10/0x10 [ +0.000009] ret_from_fork+0x31/0x50 [ +0.000009] ? __pfx_kthread+0x10/0x10 [ +0.000008] ret_from_fork_asm+0x1a/0x30 [ +0.000012] </TASK> [ +0.000046] ---[ end trace ]--- Reported-by: Roland Vet <vet.roland@protonmail.com> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This lets us print the exact location in the journal if it was found in the journal, or correctly print if it was found in the superblock. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>