Currently btrfs handles checksum validation and repair in the end I/O
handler for the btrfs_bio. This leads to a lot of duplicate code
plus issues with varying semantics or bugs, e.g.
- the until recently broken repair for compressed extents
- the fact that encoded reads validate the checksums but do not kick
of read repair
- the inconsistent checking of the BTRFS_FS_STATE_NO_CSUMS flag
This commit revamps the checksum validation and repair code to instead
work below the btrfs_submit_bio interfaces.
In case of a checksum failure (or a plain old I/O error), the repair
is now kicked off before the upper level ->end_io handler is invoked.
Progress of an in-progress repair is tracked by a small structure
that is allocated using a mempool for each original bio with failed
sectors, which holds a reference to the original bio. This new
structure is allocated using a mempool to guarantee forward progress
even under memory pressure. The mempool will be replenished when
the repair completes, just as the mempools backing the bios.
There is one significant behavior change here: If repair fails or
is impossible to start with, the whole bio will be failed to the
upper layer. This is the behavior that all I/O submitters except
for buffered I/O already emulated in their end_io handler. For
buffered I/O this now means that a large readahead request can
fail due to a single bad sector, but as readahead errors are ignored
the following readpage if the sector is actually accessed will
still be able to read. This also matches the I/O failure handling
in other file systems.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Instead of calling btrfs_lookup_bio_sums in every caller of
btrfs_submit_bio that reads data, do the call once in btrfs_submit_bio.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
All callers of btrfs_submit_bio that want to validate checksums
currently have to store a copy of the iter in the btrfs_bio. Move
the assignment into common code.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add a bbio local variable and to prepare for calling functions that
return a blk_status_t, rename the existing int used for error handling
so that ret can be reused for the blk_status_t, and a label that can be
reused for failing the passed in bio.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
All btrfs_bio I/Os are associated with an inode. Add a pointer to that
inode, which will allow to simplify a lot of calling conventions, and
which will be needed in the I/O completion path in the future.
This grow the btrfs_bio structure by a pointer, but that grows will
be offset by the removal of the device pointer soon.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There quite a few spelling mistakes as found using codespell. Fix them.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
There is a bug report that a BUG_ON() in btrfs_repair_io_failure()
(originally repair_io_failure() in v6.0 kernel) got triggered when
replacing a unreliable disk:
BTRFS warning (device sda1): csum failed root 257 ino 2397453 off 39624704 csum 0xb0d18c75 expected csum 0x4dae9c5e mirror 3
kernel BUG at fs/btrfs/extent_io.c:2380!
invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
CPU: 9 PID: 3614331 Comm: kworker/u257:2 Tainted: G OE 6.0.0-5-amd64 #1 Debian 6.0.10-2
Hardware name: Micro-Star International Co., Ltd. MS-7C60/TRX40 PRO WIFI (MS-7C60), BIOS 2.70 07/01/2021
Workqueue: btrfs-endio btrfs_end_bio_work [btrfs]
RIP: 0010:repair_io_failure+0x24a/0x260 [btrfs]
Call Trace:
<TASK>
clean_io_failure+0x14d/0x180 [btrfs]
end_bio_extent_readpage+0x412/0x6e0 [btrfs]
? __switch_to+0x106/0x420
process_one_work+0x1c7/0x380
worker_thread+0x4d/0x380
? rescuer_thread+0x3a0/0x3a0
kthread+0xe9/0x110
? kthread_complete_and_exit+0x20/0x20
ret_from_fork+0x22/0x30
[CAUSE]
Before the BUG_ON(), we got some read errors from the replace target
first, note the mirror number (3, which is beyond RAID1 duplication,
thus it's read from the replace target device).
Then at the BUG_ON() location, we are trying to writeback the repaired
sectors back the failed device.
The check looks like this:
ret = btrfs_map_block(fs_info, BTRFS_MAP_WRITE, logical,
&map_length, &bioc, mirror_num);
if (ret)
goto out_counter_dec;
BUG_ON(mirror_num != bioc->mirror_num);
But inside btrfs_map_block(), we can modify bioc->mirror_num especially
for dev-replace:
if (dev_replace_is_ongoing && mirror_num == map->num_stripes + 1 &&
!need_full_stripe(op) && dev_replace->tgtdev != NULL) {
ret = get_extra_mirror_from_replace(fs_info, logical, *length,
dev_replace->srcdev->devid,
&mirror_num,
&physical_to_patch_in_first_stripe);
patch_the_first_stripe_for_dev_replace = 1;
}
Thus if we're repairing the replace target device, we're going to
trigger that BUG_ON().
But in reality, the read failure from the replace target device may be
that, our replace hasn't reached the range we're reading, thus we're
reading garbage, but with replace running, the range would be properly
filled later.
Thus in that case, we don't need to do anything but let the replace
routine to handle it.
[FIX]
Instead of a BUG_ON(), just skip the repair if we're repairing the
device replace target device.
Reported-by: 小太 <nospam@kota.moe>
Link: https://lore.kernel.org/linux-btrfs/CACsxjPYyJGQZ+yvjzxA1Nn2LuqkYqTCcUH43S=+wXhyf8S00Ag@mail.gmail.com/
CC: stable@vger.kernel.org # 6.0+
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
repair_io_failure ties directly into all the glory low-level details of
mapping a bio with a logic address to the actual physical location.
Move it right below btrfs_submit_bio to keep all the related logic
together.
Also move btrfs_repair_eb_io_failure to its caller in disk-io.c now that
repair_io_failure is available in a header.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The code used by btrfs_submit_bio only interacts with the rest of
volumes.c through __btrfs_map_block (which itself is a more generic
version of two exported helpers) and does not really have anything
to do with volumes.c. Create a new bio.c file and a bio.h header
going along with it for the btrfs_bio-based storage layer, which
will grow even more going forward.
Also update the file with my copyright notice given that a large
part of the moved code was written or rewritten by me.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
