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path: root/fs/btrfs/raid56.h
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2015-08-09Btrfs: add RAID 5/6 BTRFS_RBIO_REBUILD_MISSING operationOmar Sandoval
The current RAID 5/6 recovery code isn't quite prepared to handle missing devices. In particular, it expects a bio that we previously attempted to use in the read path, meaning that it has valid pages allocated. However, missing devices have a NULL blkdev, and we can't call bio_add_page() on a bio with a NULL blkdev. We could do manual manipulation of bio->bi_io_vec, but that's pretty gross. So instead, add a separate path that allows us to manually add pages to the rbio. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-01-22Btrfs: Make raid_map array be inlined in btrfs_bio structureZhao Lei
It can make code more simple and clear, we need not care about free bbio and raid_map together. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-12-03Btrfs, raid56: fix use-after-free problem in the final device replace ↵Miao Xie
procedure on raid56 The commit c404e0dc (Btrfs: fix use-after-free in the finishing procedure of the device replace) fixed a use-after-free problem which happened when removing the source device at the end of device replace, but at that time, btrfs didn't support device replace on raid56, so we didn't fix the problem on the raid56 profile. Currently, we implemented device replace for raid56, so we need kick that problem out before we enable that function for raid56. The fix method is very simple, we just increase the bio per-cpu counter before we submit a raid56 io, and decrease the counter when the raid56 io ends. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
2014-12-03Btrfs, raid56: support parity scrub on raid56Miao Xie
The implementation is: - Read and check all the data with checksum in the same stripe. All the data which has checksum is COW data, and we are sure that it is not changed though we don't lock the stripe. because the space of that data just can be reclaimed after the current transction is committed, and then the fs can use it to store the other data, but when doing scrub, we hold the current transaction, that is that data can not be recovered, it is safe that read and check it out of the stripe lock. - Lock the stripe - Read out all the data without checksum and parity The data without checksum and the parity may be changed if we don't lock the stripe, so we need read it in the stripe lock context. - Check the parity - Re-calculate the new parity and write back it if the old parity is not right - Unlock the stripe If we can not read out the data or the data we read is corrupted, we will try to repair it. If the repair fails. we will mark the horizontal sub-stripe(pages on the same horizontal) as corrupted sub-stripe, and we will skip the parity check and repair of that horizontal sub-stripe. And in order to skip the horizontal sub-stripe that has no data, we introduce a bitmap. If there is some data on the horizontal sub-stripe, we will the relative bit to 1, and when we check and repair the parity, we will skip those horizontal sub-stripes that the relative bits is 0. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
2014-12-03Btrfs, scrub: repair the common data on RAID5/6 if it is corruptedMiao Xie
This patch implement the RAID5/6 common data repair function, the implementation is similar to the scrub on the other RAID such as RAID1, the differentia is that we don't read the data from the mirror, we use the data repair function of RAID5/6. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
2013-02-01Btrfs: RAID5 and RAID6David Woodhouse
This builds on David Woodhouse's original Btrfs raid5/6 implementation. The code has changed quite a bit, blame Chris Mason for any bugs. Read/modify/write is done after the higher levels of the filesystem have prepared a given bio. This means the higher layers are not responsible for building full stripes, and they don't need to query for the topology of the extents that may get allocated during delayed allocation runs. It also means different files can easily share the same stripe. But, it does expose us to incorrect parity if we crash or lose power while doing a read/modify/write cycle. This will be addressed in a later commit. Scrub is unable to repair crc errors on raid5/6 chunks. Discard does not work on raid5/6 (yet) The stripe size is fixed at 64KiB per disk. This will be tunable in a later commit. Signed-off-by: Chris Mason <chris.mason@fusionio.com>