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![Qu Wenruo](/assets/img/avatar_default.png)
commitf6065f8ede
upstream. [BUG] There is a small workload which will always fail with recent kernel: (A simplified version from btrfs/125 test case) mkfs.btrfs -f -m raid5 -d raid5 -b 1G $dev1 $dev2 $dev3 mount $dev1 $mnt xfs_io -f -c "pwrite -S 0xee 0 1M" $mnt/file1 sync umount $mnt btrfs dev scan -u $dev3 mount -o degraded $dev1 $mnt xfs_io -f -c "pwrite -S 0xff 0 128M" $mnt/file2 umount $mnt btrfs dev scan mount $dev1 $mnt btrfs balance start --full-balance $mnt umount $mnt The failure is always failed to read some tree blocks: BTRFS info (device dm-4): relocating block group 217710592 flags data|raid5 BTRFS error (device dm-4): parent transid verify failed on 38993920 wanted 9 found 7 BTRFS error (device dm-4): parent transid verify failed on 38993920 wanted 9 found 7 ... [CAUSE] With the recently added debug output, we can see all RAID56 operations related to full stripe 38928384: 56.1183: raid56_read_partial: full_stripe=38928384 devid=2 type=DATA1 offset=0 opf=0x0 physical=9502720 len=65536 56.1185: raid56_read_partial: full_stripe=38928384 devid=3 type=DATA2 offset=16384 opf=0x0 physical=9519104 len=16384 56.1185: raid56_read_partial: full_stripe=38928384 devid=3 type=DATA2 offset=49152 opf=0x0 physical=9551872 len=16384 56.1187: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=0 opf=0x1 physical=9502720 len=16384 56.1188: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=32768 opf=0x1 physical=9535488 len=16384 56.1188: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=0 opf=0x1 physical=30474240 len=16384 56.1189: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=32768 opf=0x1 physical=30507008 len=16384 56.1218: raid56_write_stripe: full_stripe=38928384 devid=3 type=DATA2 offset=49152 opf=0x1 physical=9551872 len=16384 56.1219: raid56_write_stripe: full_stripe=38928384 devid=1 type=PQ1 offset=49152 opf=0x1 physical=30523392 len=16384 56.2721: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2 56.2723: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2 56.2724: raid56_parity_recover: full stripe=38928384 eb=39010304 mirror=2 Before we enter raid56_parity_recover(), we have triggered some metadata write for the full stripe 38928384, this leads to us to read all the sectors from disk. Furthermore, btrfs raid56 write will cache its calculated P/Q sectors to avoid unnecessary read. This means, for that full stripe, after any partial write, we will have stale data, along with P/Q calculated using that stale data. Thankfully due to patch "btrfs: only write the sectors in the vertical stripe which has data stripes" we haven't submitted all the corrupted P/Q to disk. When we really need to recover certain range, aka in raid56_parity_recover(), we will use the cached rbio, along with its cached sectors (the full stripe is all cached). This explains why we have no event raid56_scrub_read_recover() triggered. Since we have the cached P/Q which is calculated using the stale data, the recovered one will just be stale. In our particular test case, it will always return the same incorrect metadata, thus causing the same error message "parent transid verify failed on 39010304 wanted 9 found 7" again and again. [BTRFS DESTRUCTIVE RMW PROBLEM] Test case btrfs/125 (and above workload) always has its trouble with the destructive read-modify-write (RMW) cycle: 0 32K 64K Data1: | Good | Good | Data2: | Bad | Bad | Parity: | Good | Good | In above case, if we trigger any write into Data1, we will use the bad data in Data2 to re-generate parity, killing the only chance to recovery Data2, thus Data2 is lost forever. This destructive RMW cycle is not specific to btrfs RAID56, but there are some btrfs specific behaviors making the case even worse: - Btrfs will cache sectors for unrelated vertical stripes. In above example, if we're only writing into 0~32K range, btrfs will still read data range (32K ~ 64K) of Data1, and (64K~128K) of Data2. This behavior is to cache sectors for later update. Incidentally commitd4e28d9b5f
("btrfs: raid56: make steal_rbio() subpage compatible") has a bug which makes RAID56 to never trust the cached sectors, thus slightly improve the situation for recovery. Unfortunately, follow up fix "btrfs: update stripe_sectors::uptodate in steal_rbio" will revert the behavior back to the old one. - Btrfs raid56 partial write will update all P/Q sectors and cache them This means, even if data at (64K ~ 96K) of Data2 is free space, and only (96K ~ 128K) of Data2 is really stale data. And we write into that (96K ~ 128K), we will update all the parity sectors for the full stripe. This unnecessary behavior will completely kill the chance of recovery. Thankfully, an unrelated optimization "btrfs: only write the sectors in the vertical stripe which has data stripes" will prevent submitting the write bio for untouched vertical sectors. That optimization will keep the on-disk P/Q untouched for a chance for later recovery. [FIX] Although we have no good way to completely fix the destructive RMW (unless we go full scrub for each partial write), we can still limit the damage. With patch "btrfs: only write the sectors in the vertical stripe which has data stripes" now we won't really submit the P/Q of unrelated vertical stripes, so the on-disk P/Q should still be fine. Now we really need to do is just drop all the cached sectors when doing recovery. By this, we have a chance to read the original P/Q from disk, and have a chance to recover the stale data, while still keep the cache to speed up regular write path. In fact, just dropping all the cache for recovery path is good enough to allow the test case btrfs/125 along with the small script to pass reliably. The lack of metadata write after the degraded mount, and forced metadata COW is saving us this time. So this patch will fix the behavior by not trust any cache in __raid56_parity_recover(), to solve the problem while still keep the cache useful. But please note that this test pass DOES NOT mean we have solved the destructive RMW problem, we just do better damage control a little better. Related patches: - btrfs: only write the sectors in the vertical stripe -d4e28d9b5f
("btrfs: raid56: make steal_rbio() subpage compatible") - btrfs: update stripe_sectors::uptodate in steal_rbio Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2792 lines
69 KiB
C
2792 lines
69 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2012 Fusion-io All rights reserved.
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* Copyright (C) 2012 Intel Corp. All rights reserved.
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*/
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#include <linux/sched.h>
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#include <linux/bio.h>
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#include <linux/slab.h>
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#include <linux/blkdev.h>
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#include <linux/raid/pq.h>
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#include <linux/hash.h>
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#include <linux/list_sort.h>
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#include <linux/raid/xor.h>
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#include <linux/mm.h>
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#include "ctree.h"
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#include "disk-io.h"
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#include "volumes.h"
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#include "raid56.h"
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#include "async-thread.h"
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/* set when additional merges to this rbio are not allowed */
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#define RBIO_RMW_LOCKED_BIT 1
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/*
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* set when this rbio is sitting in the hash, but it is just a cache
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* of past RMW
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*/
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#define RBIO_CACHE_BIT 2
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/*
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* set when it is safe to trust the stripe_pages for caching
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*/
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#define RBIO_CACHE_READY_BIT 3
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#define RBIO_CACHE_SIZE 1024
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#define BTRFS_STRIPE_HASH_TABLE_BITS 11
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/* Used by the raid56 code to lock stripes for read/modify/write */
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struct btrfs_stripe_hash {
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struct list_head hash_list;
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spinlock_t lock;
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};
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/* Used by the raid56 code to lock stripes for read/modify/write */
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struct btrfs_stripe_hash_table {
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struct list_head stripe_cache;
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spinlock_t cache_lock;
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int cache_size;
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struct btrfs_stripe_hash table[];
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};
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enum btrfs_rbio_ops {
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BTRFS_RBIO_WRITE,
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BTRFS_RBIO_READ_REBUILD,
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BTRFS_RBIO_PARITY_SCRUB,
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BTRFS_RBIO_REBUILD_MISSING,
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};
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struct btrfs_raid_bio {
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struct btrfs_fs_info *fs_info;
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struct btrfs_bio *bbio;
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/* while we're doing rmw on a stripe
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* we put it into a hash table so we can
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* lock the stripe and merge more rbios
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* into it.
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*/
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struct list_head hash_list;
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/*
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* LRU list for the stripe cache
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*/
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struct list_head stripe_cache;
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/*
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* for scheduling work in the helper threads
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*/
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struct btrfs_work work;
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/*
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* bio list and bio_list_lock are used
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* to add more bios into the stripe
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* in hopes of avoiding the full rmw
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*/
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struct bio_list bio_list;
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spinlock_t bio_list_lock;
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/* also protected by the bio_list_lock, the
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* plug list is used by the plugging code
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* to collect partial bios while plugged. The
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* stripe locking code also uses it to hand off
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* the stripe lock to the next pending IO
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*/
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struct list_head plug_list;
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/*
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* flags that tell us if it is safe to
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* merge with this bio
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*/
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unsigned long flags;
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/* size of each individual stripe on disk */
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int stripe_len;
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/* number of data stripes (no p/q) */
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int nr_data;
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int real_stripes;
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int stripe_npages;
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/*
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* set if we're doing a parity rebuild
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* for a read from higher up, which is handled
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* differently from a parity rebuild as part of
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* rmw
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*/
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enum btrfs_rbio_ops operation;
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/* first bad stripe */
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int faila;
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/* second bad stripe (for raid6 use) */
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int failb;
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int scrubp;
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/*
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* number of pages needed to represent the full
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* stripe
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*/
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int nr_pages;
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/*
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* size of all the bios in the bio_list. This
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* helps us decide if the rbio maps to a full
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* stripe or not
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*/
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int bio_list_bytes;
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int generic_bio_cnt;
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refcount_t refs;
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atomic_t stripes_pending;
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atomic_t error;
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/*
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* these are two arrays of pointers. We allocate the
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* rbio big enough to hold them both and setup their
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* locations when the rbio is allocated
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*/
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/* pointers to pages that we allocated for
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* reading/writing stripes directly from the disk (including P/Q)
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*/
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struct page **stripe_pages;
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/*
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* pointers to the pages in the bio_list. Stored
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* here for faster lookup
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*/
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struct page **bio_pages;
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/*
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* bitmap to record which horizontal stripe has data
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*/
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unsigned long *dbitmap;
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/* allocated with real_stripes-many pointers for finish_*() calls */
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void **finish_pointers;
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/* allocated with stripe_npages-many bits for finish_*() calls */
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unsigned long *finish_pbitmap;
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};
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static int __raid56_parity_recover(struct btrfs_raid_bio *rbio);
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static noinline void finish_rmw(struct btrfs_raid_bio *rbio);
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static void rmw_work(struct btrfs_work *work);
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static void read_rebuild_work(struct btrfs_work *work);
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static int fail_bio_stripe(struct btrfs_raid_bio *rbio, struct bio *bio);
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static int fail_rbio_index(struct btrfs_raid_bio *rbio, int failed);
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static void __free_raid_bio(struct btrfs_raid_bio *rbio);
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static void index_rbio_pages(struct btrfs_raid_bio *rbio);
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static int alloc_rbio_pages(struct btrfs_raid_bio *rbio);
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static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
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int need_check);
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static void scrub_parity_work(struct btrfs_work *work);
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static void start_async_work(struct btrfs_raid_bio *rbio, btrfs_func_t work_func)
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{
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btrfs_init_work(&rbio->work, work_func, NULL, NULL);
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btrfs_queue_work(rbio->fs_info->rmw_workers, &rbio->work);
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}
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/*
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* the stripe hash table is used for locking, and to collect
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* bios in hopes of making a full stripe
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*/
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int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info)
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{
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struct btrfs_stripe_hash_table *table;
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struct btrfs_stripe_hash_table *x;
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struct btrfs_stripe_hash *cur;
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struct btrfs_stripe_hash *h;
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int num_entries = 1 << BTRFS_STRIPE_HASH_TABLE_BITS;
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int i;
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int table_size;
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if (info->stripe_hash_table)
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return 0;
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/*
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* The table is large, starting with order 4 and can go as high as
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* order 7 in case lock debugging is turned on.
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*
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* Try harder to allocate and fallback to vmalloc to lower the chance
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* of a failing mount.
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*/
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table_size = sizeof(*table) + sizeof(*h) * num_entries;
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table = kvzalloc(table_size, GFP_KERNEL);
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if (!table)
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return -ENOMEM;
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spin_lock_init(&table->cache_lock);
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INIT_LIST_HEAD(&table->stripe_cache);
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h = table->table;
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for (i = 0; i < num_entries; i++) {
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cur = h + i;
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INIT_LIST_HEAD(&cur->hash_list);
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spin_lock_init(&cur->lock);
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}
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x = cmpxchg(&info->stripe_hash_table, NULL, table);
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if (x)
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kvfree(x);
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return 0;
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}
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/*
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* caching an rbio means to copy anything from the
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* bio_pages array into the stripe_pages array. We
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* use the page uptodate bit in the stripe cache array
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* to indicate if it has valid data
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*
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* once the caching is done, we set the cache ready
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* bit.
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*/
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static void cache_rbio_pages(struct btrfs_raid_bio *rbio)
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{
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int i;
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char *s;
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char *d;
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int ret;
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ret = alloc_rbio_pages(rbio);
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if (ret)
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return;
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for (i = 0; i < rbio->nr_pages; i++) {
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if (!rbio->bio_pages[i])
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continue;
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s = kmap(rbio->bio_pages[i]);
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d = kmap(rbio->stripe_pages[i]);
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copy_page(d, s);
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kunmap(rbio->bio_pages[i]);
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kunmap(rbio->stripe_pages[i]);
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SetPageUptodate(rbio->stripe_pages[i]);
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}
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set_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
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}
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/*
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* we hash on the first logical address of the stripe
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*/
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static int rbio_bucket(struct btrfs_raid_bio *rbio)
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{
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u64 num = rbio->bbio->raid_map[0];
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/*
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* we shift down quite a bit. We're using byte
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* addressing, and most of the lower bits are zeros.
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* This tends to upset hash_64, and it consistently
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* returns just one or two different values.
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*
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* shifting off the lower bits fixes things.
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*/
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return hash_64(num >> 16, BTRFS_STRIPE_HASH_TABLE_BITS);
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}
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/*
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* stealing an rbio means taking all the uptodate pages from the stripe
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* array in the source rbio and putting them into the destination rbio
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*/
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static void steal_rbio(struct btrfs_raid_bio *src, struct btrfs_raid_bio *dest)
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{
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int i;
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struct page *s;
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struct page *d;
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if (!test_bit(RBIO_CACHE_READY_BIT, &src->flags))
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return;
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for (i = 0; i < dest->nr_pages; i++) {
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s = src->stripe_pages[i];
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if (!s || !PageUptodate(s)) {
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continue;
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}
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d = dest->stripe_pages[i];
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if (d)
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__free_page(d);
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dest->stripe_pages[i] = s;
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src->stripe_pages[i] = NULL;
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}
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}
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/*
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* merging means we take the bio_list from the victim and
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* splice it into the destination. The victim should
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* be discarded afterwards.
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*
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* must be called with dest->rbio_list_lock held
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*/
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static void merge_rbio(struct btrfs_raid_bio *dest,
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struct btrfs_raid_bio *victim)
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{
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bio_list_merge(&dest->bio_list, &victim->bio_list);
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dest->bio_list_bytes += victim->bio_list_bytes;
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/* Also inherit the bitmaps from @victim. */
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bitmap_or(dest->dbitmap, victim->dbitmap, dest->dbitmap,
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dest->stripe_npages);
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dest->generic_bio_cnt += victim->generic_bio_cnt;
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bio_list_init(&victim->bio_list);
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}
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/*
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* used to prune items that are in the cache. The caller
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* must hold the hash table lock.
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*/
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static void __remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
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{
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int bucket = rbio_bucket(rbio);
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struct btrfs_stripe_hash_table *table;
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struct btrfs_stripe_hash *h;
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int freeit = 0;
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/*
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* check the bit again under the hash table lock.
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*/
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if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
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return;
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table = rbio->fs_info->stripe_hash_table;
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h = table->table + bucket;
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/* hold the lock for the bucket because we may be
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* removing it from the hash table
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*/
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spin_lock(&h->lock);
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/*
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* hold the lock for the bio list because we need
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* to make sure the bio list is empty
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*/
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spin_lock(&rbio->bio_list_lock);
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if (test_and_clear_bit(RBIO_CACHE_BIT, &rbio->flags)) {
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list_del_init(&rbio->stripe_cache);
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table->cache_size -= 1;
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freeit = 1;
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/* if the bio list isn't empty, this rbio is
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* still involved in an IO. We take it out
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* of the cache list, and drop the ref that
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* was held for the list.
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*
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* If the bio_list was empty, we also remove
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* the rbio from the hash_table, and drop
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* the corresponding ref
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*/
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if (bio_list_empty(&rbio->bio_list)) {
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if (!list_empty(&rbio->hash_list)) {
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list_del_init(&rbio->hash_list);
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refcount_dec(&rbio->refs);
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BUG_ON(!list_empty(&rbio->plug_list));
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}
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}
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}
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spin_unlock(&rbio->bio_list_lock);
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spin_unlock(&h->lock);
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if (freeit)
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__free_raid_bio(rbio);
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}
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/*
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* prune a given rbio from the cache
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*/
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static void remove_rbio_from_cache(struct btrfs_raid_bio *rbio)
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{
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struct btrfs_stripe_hash_table *table;
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unsigned long flags;
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if (!test_bit(RBIO_CACHE_BIT, &rbio->flags))
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return;
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|
|
table = rbio->fs_info->stripe_hash_table;
|
|
|
|
spin_lock_irqsave(&table->cache_lock, flags);
|
|
__remove_rbio_from_cache(rbio);
|
|
spin_unlock_irqrestore(&table->cache_lock, flags);
|
|
}
|
|
|
|
/*
|
|
* remove everything in the cache
|
|
*/
|
|
static void btrfs_clear_rbio_cache(struct btrfs_fs_info *info)
|
|
{
|
|
struct btrfs_stripe_hash_table *table;
|
|
unsigned long flags;
|
|
struct btrfs_raid_bio *rbio;
|
|
|
|
table = info->stripe_hash_table;
|
|
|
|
spin_lock_irqsave(&table->cache_lock, flags);
|
|
while (!list_empty(&table->stripe_cache)) {
|
|
rbio = list_entry(table->stripe_cache.next,
|
|
struct btrfs_raid_bio,
|
|
stripe_cache);
|
|
__remove_rbio_from_cache(rbio);
|
|
}
|
|
spin_unlock_irqrestore(&table->cache_lock, flags);
|
|
}
|
|
|
|
/*
|
|
* remove all cached entries and free the hash table
|
|
* used by unmount
|
|
*/
|
|
void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info)
|
|
{
|
|
if (!info->stripe_hash_table)
|
|
return;
|
|
btrfs_clear_rbio_cache(info);
|
|
kvfree(info->stripe_hash_table);
|
|
info->stripe_hash_table = NULL;
|
|
}
|
|
|
|
/*
|
|
* insert an rbio into the stripe cache. It
|
|
* must have already been prepared by calling
|
|
* cache_rbio_pages
|
|
*
|
|
* If this rbio was already cached, it gets
|
|
* moved to the front of the lru.
|
|
*
|
|
* If the size of the rbio cache is too big, we
|
|
* prune an item.
|
|
*/
|
|
static void cache_rbio(struct btrfs_raid_bio *rbio)
|
|
{
|
|
struct btrfs_stripe_hash_table *table;
|
|
unsigned long flags;
|
|
|
|
if (!test_bit(RBIO_CACHE_READY_BIT, &rbio->flags))
|
|
return;
|
|
|
|
table = rbio->fs_info->stripe_hash_table;
|
|
|
|
spin_lock_irqsave(&table->cache_lock, flags);
|
|
spin_lock(&rbio->bio_list_lock);
|
|
|
|
/* bump our ref if we were not in the list before */
|
|
if (!test_and_set_bit(RBIO_CACHE_BIT, &rbio->flags))
|
|
refcount_inc(&rbio->refs);
|
|
|
|
if (!list_empty(&rbio->stripe_cache)){
|
|
list_move(&rbio->stripe_cache, &table->stripe_cache);
|
|
} else {
|
|
list_add(&rbio->stripe_cache, &table->stripe_cache);
|
|
table->cache_size += 1;
|
|
}
|
|
|
|
spin_unlock(&rbio->bio_list_lock);
|
|
|
|
if (table->cache_size > RBIO_CACHE_SIZE) {
|
|
struct btrfs_raid_bio *found;
|
|
|
|
found = list_entry(table->stripe_cache.prev,
|
|
struct btrfs_raid_bio,
|
|
stripe_cache);
|
|
|
|
if (found != rbio)
|
|
__remove_rbio_from_cache(found);
|
|
}
|
|
|
|
spin_unlock_irqrestore(&table->cache_lock, flags);
|
|
}
|
|
|
|
/*
|
|
* helper function to run the xor_blocks api. It is only
|
|
* able to do MAX_XOR_BLOCKS at a time, so we need to
|
|
* loop through.
|
|
*/
|
|
static void run_xor(void **pages, int src_cnt, ssize_t len)
|
|
{
|
|
int src_off = 0;
|
|
int xor_src_cnt = 0;
|
|
void *dest = pages[src_cnt];
|
|
|
|
while(src_cnt > 0) {
|
|
xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
|
|
xor_blocks(xor_src_cnt, len, dest, pages + src_off);
|
|
|
|
src_cnt -= xor_src_cnt;
|
|
src_off += xor_src_cnt;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Returns true if the bio list inside this rbio covers an entire stripe (no
|
|
* rmw required).
|
|
*/
|
|
static int rbio_is_full(struct btrfs_raid_bio *rbio)
|
|
{
|
|
unsigned long flags;
|
|
unsigned long size = rbio->bio_list_bytes;
|
|
int ret = 1;
|
|
|
|
spin_lock_irqsave(&rbio->bio_list_lock, flags);
|
|
if (size != rbio->nr_data * rbio->stripe_len)
|
|
ret = 0;
|
|
BUG_ON(size > rbio->nr_data * rbio->stripe_len);
|
|
spin_unlock_irqrestore(&rbio->bio_list_lock, flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* returns 1 if it is safe to merge two rbios together.
|
|
* The merging is safe if the two rbios correspond to
|
|
* the same stripe and if they are both going in the same
|
|
* direction (read vs write), and if neither one is
|
|
* locked for final IO
|
|
*
|
|
* The caller is responsible for locking such that
|
|
* rmw_locked is safe to test
|
|
*/
|
|
static int rbio_can_merge(struct btrfs_raid_bio *last,
|
|
struct btrfs_raid_bio *cur)
|
|
{
|
|
if (test_bit(RBIO_RMW_LOCKED_BIT, &last->flags) ||
|
|
test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags))
|
|
return 0;
|
|
|
|
/*
|
|
* we can't merge with cached rbios, since the
|
|
* idea is that when we merge the destination
|
|
* rbio is going to run our IO for us. We can
|
|
* steal from cached rbios though, other functions
|
|
* handle that.
|
|
*/
|
|
if (test_bit(RBIO_CACHE_BIT, &last->flags) ||
|
|
test_bit(RBIO_CACHE_BIT, &cur->flags))
|
|
return 0;
|
|
|
|
if (last->bbio->raid_map[0] !=
|
|
cur->bbio->raid_map[0])
|
|
return 0;
|
|
|
|
/* we can't merge with different operations */
|
|
if (last->operation != cur->operation)
|
|
return 0;
|
|
/*
|
|
* We've need read the full stripe from the drive.
|
|
* check and repair the parity and write the new results.
|
|
*
|
|
* We're not allowed to add any new bios to the
|
|
* bio list here, anyone else that wants to
|
|
* change this stripe needs to do their own rmw.
|
|
*/
|
|
if (last->operation == BTRFS_RBIO_PARITY_SCRUB)
|
|
return 0;
|
|
|
|
if (last->operation == BTRFS_RBIO_REBUILD_MISSING)
|
|
return 0;
|
|
|
|
if (last->operation == BTRFS_RBIO_READ_REBUILD) {
|
|
int fa = last->faila;
|
|
int fb = last->failb;
|
|
int cur_fa = cur->faila;
|
|
int cur_fb = cur->failb;
|
|
|
|
if (last->faila >= last->failb) {
|
|
fa = last->failb;
|
|
fb = last->faila;
|
|
}
|
|
|
|
if (cur->faila >= cur->failb) {
|
|
cur_fa = cur->failb;
|
|
cur_fb = cur->faila;
|
|
}
|
|
|
|
if (fa != cur_fa || fb != cur_fb)
|
|
return 0;
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
static int rbio_stripe_page_index(struct btrfs_raid_bio *rbio, int stripe,
|
|
int index)
|
|
{
|
|
return stripe * rbio->stripe_npages + index;
|
|
}
|
|
|
|
/*
|
|
* these are just the pages from the rbio array, not from anything
|
|
* the FS sent down to us
|
|
*/
|
|
static struct page *rbio_stripe_page(struct btrfs_raid_bio *rbio, int stripe,
|
|
int index)
|
|
{
|
|
return rbio->stripe_pages[rbio_stripe_page_index(rbio, stripe, index)];
|
|
}
|
|
|
|
/*
|
|
* helper to index into the pstripe
|
|
*/
|
|
static struct page *rbio_pstripe_page(struct btrfs_raid_bio *rbio, int index)
|
|
{
|
|
return rbio_stripe_page(rbio, rbio->nr_data, index);
|
|
}
|
|
|
|
/*
|
|
* helper to index into the qstripe, returns null
|
|
* if there is no qstripe
|
|
*/
|
|
static struct page *rbio_qstripe_page(struct btrfs_raid_bio *rbio, int index)
|
|
{
|
|
if (rbio->nr_data + 1 == rbio->real_stripes)
|
|
return NULL;
|
|
return rbio_stripe_page(rbio, rbio->nr_data + 1, index);
|
|
}
|
|
|
|
/*
|
|
* The first stripe in the table for a logical address
|
|
* has the lock. rbios are added in one of three ways:
|
|
*
|
|
* 1) Nobody has the stripe locked yet. The rbio is given
|
|
* the lock and 0 is returned. The caller must start the IO
|
|
* themselves.
|
|
*
|
|
* 2) Someone has the stripe locked, but we're able to merge
|
|
* with the lock owner. The rbio is freed and the IO will
|
|
* start automatically along with the existing rbio. 1 is returned.
|
|
*
|
|
* 3) Someone has the stripe locked, but we're not able to merge.
|
|
* The rbio is added to the lock owner's plug list, or merged into
|
|
* an rbio already on the plug list. When the lock owner unlocks,
|
|
* the next rbio on the list is run and the IO is started automatically.
|
|
* 1 is returned
|
|
*
|
|
* If we return 0, the caller still owns the rbio and must continue with
|
|
* IO submission. If we return 1, the caller must assume the rbio has
|
|
* already been freed.
|
|
*/
|
|
static noinline int lock_stripe_add(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int bucket = rbio_bucket(rbio);
|
|
struct btrfs_stripe_hash *h = rbio->fs_info->stripe_hash_table->table + bucket;
|
|
struct btrfs_raid_bio *cur;
|
|
struct btrfs_raid_bio *pending;
|
|
unsigned long flags;
|
|
struct btrfs_raid_bio *freeit = NULL;
|
|
struct btrfs_raid_bio *cache_drop = NULL;
|
|
int ret = 0;
|
|
|
|
spin_lock_irqsave(&h->lock, flags);
|
|
list_for_each_entry(cur, &h->hash_list, hash_list) {
|
|
if (cur->bbio->raid_map[0] == rbio->bbio->raid_map[0]) {
|
|
spin_lock(&cur->bio_list_lock);
|
|
|
|
/* can we steal this cached rbio's pages? */
|
|
if (bio_list_empty(&cur->bio_list) &&
|
|
list_empty(&cur->plug_list) &&
|
|
test_bit(RBIO_CACHE_BIT, &cur->flags) &&
|
|
!test_bit(RBIO_RMW_LOCKED_BIT, &cur->flags)) {
|
|
list_del_init(&cur->hash_list);
|
|
refcount_dec(&cur->refs);
|
|
|
|
steal_rbio(cur, rbio);
|
|
cache_drop = cur;
|
|
spin_unlock(&cur->bio_list_lock);
|
|
|
|
goto lockit;
|
|
}
|
|
|
|
/* can we merge into the lock owner? */
|
|
if (rbio_can_merge(cur, rbio)) {
|
|
merge_rbio(cur, rbio);
|
|
spin_unlock(&cur->bio_list_lock);
|
|
freeit = rbio;
|
|
ret = 1;
|
|
goto out;
|
|
}
|
|
|
|
|
|
/*
|
|
* we couldn't merge with the running
|
|
* rbio, see if we can merge with the
|
|
* pending ones. We don't have to
|
|
* check for rmw_locked because there
|
|
* is no way they are inside finish_rmw
|
|
* right now
|
|
*/
|
|
list_for_each_entry(pending, &cur->plug_list,
|
|
plug_list) {
|
|
if (rbio_can_merge(pending, rbio)) {
|
|
merge_rbio(pending, rbio);
|
|
spin_unlock(&cur->bio_list_lock);
|
|
freeit = rbio;
|
|
ret = 1;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* no merging, put us on the tail of the plug list,
|
|
* our rbio will be started with the currently
|
|
* running rbio unlocks
|
|
*/
|
|
list_add_tail(&rbio->plug_list, &cur->plug_list);
|
|
spin_unlock(&cur->bio_list_lock);
|
|
ret = 1;
|
|
goto out;
|
|
}
|
|
}
|
|
lockit:
|
|
refcount_inc(&rbio->refs);
|
|
list_add(&rbio->hash_list, &h->hash_list);
|
|
out:
|
|
spin_unlock_irqrestore(&h->lock, flags);
|
|
if (cache_drop)
|
|
remove_rbio_from_cache(cache_drop);
|
|
if (freeit)
|
|
__free_raid_bio(freeit);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* called as rmw or parity rebuild is completed. If the plug list has more
|
|
* rbios waiting for this stripe, the next one on the list will be started
|
|
*/
|
|
static noinline void unlock_stripe(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int bucket;
|
|
struct btrfs_stripe_hash *h;
|
|
unsigned long flags;
|
|
int keep_cache = 0;
|
|
|
|
bucket = rbio_bucket(rbio);
|
|
h = rbio->fs_info->stripe_hash_table->table + bucket;
|
|
|
|
if (list_empty(&rbio->plug_list))
|
|
cache_rbio(rbio);
|
|
|
|
spin_lock_irqsave(&h->lock, flags);
|
|
spin_lock(&rbio->bio_list_lock);
|
|
|
|
if (!list_empty(&rbio->hash_list)) {
|
|
/*
|
|
* if we're still cached and there is no other IO
|
|
* to perform, just leave this rbio here for others
|
|
* to steal from later
|
|
*/
|
|
if (list_empty(&rbio->plug_list) &&
|
|
test_bit(RBIO_CACHE_BIT, &rbio->flags)) {
|
|
keep_cache = 1;
|
|
clear_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
|
|
BUG_ON(!bio_list_empty(&rbio->bio_list));
|
|
goto done;
|
|
}
|
|
|
|
list_del_init(&rbio->hash_list);
|
|
refcount_dec(&rbio->refs);
|
|
|
|
/*
|
|
* we use the plug list to hold all the rbios
|
|
* waiting for the chance to lock this stripe.
|
|
* hand the lock over to one of them.
|
|
*/
|
|
if (!list_empty(&rbio->plug_list)) {
|
|
struct btrfs_raid_bio *next;
|
|
struct list_head *head = rbio->plug_list.next;
|
|
|
|
next = list_entry(head, struct btrfs_raid_bio,
|
|
plug_list);
|
|
|
|
list_del_init(&rbio->plug_list);
|
|
|
|
list_add(&next->hash_list, &h->hash_list);
|
|
refcount_inc(&next->refs);
|
|
spin_unlock(&rbio->bio_list_lock);
|
|
spin_unlock_irqrestore(&h->lock, flags);
|
|
|
|
if (next->operation == BTRFS_RBIO_READ_REBUILD)
|
|
start_async_work(next, read_rebuild_work);
|
|
else if (next->operation == BTRFS_RBIO_REBUILD_MISSING) {
|
|
steal_rbio(rbio, next);
|
|
start_async_work(next, read_rebuild_work);
|
|
} else if (next->operation == BTRFS_RBIO_WRITE) {
|
|
steal_rbio(rbio, next);
|
|
start_async_work(next, rmw_work);
|
|
} else if (next->operation == BTRFS_RBIO_PARITY_SCRUB) {
|
|
steal_rbio(rbio, next);
|
|
start_async_work(next, scrub_parity_work);
|
|
}
|
|
|
|
goto done_nolock;
|
|
}
|
|
}
|
|
done:
|
|
spin_unlock(&rbio->bio_list_lock);
|
|
spin_unlock_irqrestore(&h->lock, flags);
|
|
|
|
done_nolock:
|
|
if (!keep_cache)
|
|
remove_rbio_from_cache(rbio);
|
|
}
|
|
|
|
static void __free_raid_bio(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int i;
|
|
|
|
if (!refcount_dec_and_test(&rbio->refs))
|
|
return;
|
|
|
|
WARN_ON(!list_empty(&rbio->stripe_cache));
|
|
WARN_ON(!list_empty(&rbio->hash_list));
|
|
WARN_ON(!bio_list_empty(&rbio->bio_list));
|
|
|
|
for (i = 0; i < rbio->nr_pages; i++) {
|
|
if (rbio->stripe_pages[i]) {
|
|
__free_page(rbio->stripe_pages[i]);
|
|
rbio->stripe_pages[i] = NULL;
|
|
}
|
|
}
|
|
|
|
btrfs_put_bbio(rbio->bbio);
|
|
kfree(rbio);
|
|
}
|
|
|
|
static void rbio_endio_bio_list(struct bio *cur, blk_status_t err)
|
|
{
|
|
struct bio *next;
|
|
|
|
while (cur) {
|
|
next = cur->bi_next;
|
|
cur->bi_next = NULL;
|
|
cur->bi_status = err;
|
|
bio_endio(cur);
|
|
cur = next;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* this frees the rbio and runs through all the bios in the
|
|
* bio_list and calls end_io on them
|
|
*/
|
|
static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, blk_status_t err)
|
|
{
|
|
struct bio *cur = bio_list_get(&rbio->bio_list);
|
|
struct bio *extra;
|
|
|
|
if (rbio->generic_bio_cnt)
|
|
btrfs_bio_counter_sub(rbio->fs_info, rbio->generic_bio_cnt);
|
|
/*
|
|
* Clear the data bitmap, as the rbio may be cached for later usage.
|
|
* do this before before unlock_stripe() so there will be no new bio
|
|
* for this bio.
|
|
*/
|
|
bitmap_clear(rbio->dbitmap, 0, rbio->stripe_npages);
|
|
|
|
/*
|
|
* At this moment, rbio->bio_list is empty, however since rbio does not
|
|
* always have RBIO_RMW_LOCKED_BIT set and rbio is still linked on the
|
|
* hash list, rbio may be merged with others so that rbio->bio_list
|
|
* becomes non-empty.
|
|
* Once unlock_stripe() is done, rbio->bio_list will not be updated any
|
|
* more and we can call bio_endio() on all queued bios.
|
|
*/
|
|
unlock_stripe(rbio);
|
|
extra = bio_list_get(&rbio->bio_list);
|
|
__free_raid_bio(rbio);
|
|
|
|
rbio_endio_bio_list(cur, err);
|
|
if (extra)
|
|
rbio_endio_bio_list(extra, err);
|
|
}
|
|
|
|
/*
|
|
* end io function used by finish_rmw. When we finally
|
|
* get here, we've written a full stripe
|
|
*/
|
|
static void raid_write_end_io(struct bio *bio)
|
|
{
|
|
struct btrfs_raid_bio *rbio = bio->bi_private;
|
|
blk_status_t err = bio->bi_status;
|
|
int max_errors;
|
|
|
|
if (err)
|
|
fail_bio_stripe(rbio, bio);
|
|
|
|
bio_put(bio);
|
|
|
|
if (!atomic_dec_and_test(&rbio->stripes_pending))
|
|
return;
|
|
|
|
err = BLK_STS_OK;
|
|
|
|
/* OK, we have read all the stripes we need to. */
|
|
max_errors = (rbio->operation == BTRFS_RBIO_PARITY_SCRUB) ?
|
|
0 : rbio->bbio->max_errors;
|
|
if (atomic_read(&rbio->error) > max_errors)
|
|
err = BLK_STS_IOERR;
|
|
|
|
rbio_orig_end_io(rbio, err);
|
|
}
|
|
|
|
/*
|
|
* the read/modify/write code wants to use the original bio for
|
|
* any pages it included, and then use the rbio for everything
|
|
* else. This function decides if a given index (stripe number)
|
|
* and page number in that stripe fall inside the original bio
|
|
* or the rbio.
|
|
*
|
|
* if you set bio_list_only, you'll get a NULL back for any ranges
|
|
* that are outside the bio_list
|
|
*
|
|
* This doesn't take any refs on anything, you get a bare page pointer
|
|
* and the caller must bump refs as required.
|
|
*
|
|
* You must call index_rbio_pages once before you can trust
|
|
* the answers from this function.
|
|
*/
|
|
static struct page *page_in_rbio(struct btrfs_raid_bio *rbio,
|
|
int index, int pagenr, int bio_list_only)
|
|
{
|
|
int chunk_page;
|
|
struct page *p = NULL;
|
|
|
|
chunk_page = index * (rbio->stripe_len >> PAGE_SHIFT) + pagenr;
|
|
|
|
spin_lock_irq(&rbio->bio_list_lock);
|
|
p = rbio->bio_pages[chunk_page];
|
|
spin_unlock_irq(&rbio->bio_list_lock);
|
|
|
|
if (p || bio_list_only)
|
|
return p;
|
|
|
|
return rbio->stripe_pages[chunk_page];
|
|
}
|
|
|
|
/*
|
|
* number of pages we need for the entire stripe across all the
|
|
* drives
|
|
*/
|
|
static unsigned long rbio_nr_pages(unsigned long stripe_len, int nr_stripes)
|
|
{
|
|
return DIV_ROUND_UP(stripe_len, PAGE_SIZE) * nr_stripes;
|
|
}
|
|
|
|
/*
|
|
* allocation and initial setup for the btrfs_raid_bio. Not
|
|
* this does not allocate any pages for rbio->pages.
|
|
*/
|
|
static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info,
|
|
struct btrfs_bio *bbio,
|
|
u64 stripe_len)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
int nr_data = 0;
|
|
int real_stripes = bbio->num_stripes - bbio->num_tgtdevs;
|
|
int num_pages = rbio_nr_pages(stripe_len, real_stripes);
|
|
int stripe_npages = DIV_ROUND_UP(stripe_len, PAGE_SIZE);
|
|
void *p;
|
|
|
|
rbio = kzalloc(sizeof(*rbio) +
|
|
sizeof(*rbio->stripe_pages) * num_pages +
|
|
sizeof(*rbio->bio_pages) * num_pages +
|
|
sizeof(*rbio->finish_pointers) * real_stripes +
|
|
sizeof(*rbio->dbitmap) * BITS_TO_LONGS(stripe_npages) +
|
|
sizeof(*rbio->finish_pbitmap) *
|
|
BITS_TO_LONGS(stripe_npages),
|
|
GFP_NOFS);
|
|
if (!rbio)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
bio_list_init(&rbio->bio_list);
|
|
INIT_LIST_HEAD(&rbio->plug_list);
|
|
spin_lock_init(&rbio->bio_list_lock);
|
|
INIT_LIST_HEAD(&rbio->stripe_cache);
|
|
INIT_LIST_HEAD(&rbio->hash_list);
|
|
rbio->bbio = bbio;
|
|
rbio->fs_info = fs_info;
|
|
rbio->stripe_len = stripe_len;
|
|
rbio->nr_pages = num_pages;
|
|
rbio->real_stripes = real_stripes;
|
|
rbio->stripe_npages = stripe_npages;
|
|
rbio->faila = -1;
|
|
rbio->failb = -1;
|
|
refcount_set(&rbio->refs, 1);
|
|
atomic_set(&rbio->error, 0);
|
|
atomic_set(&rbio->stripes_pending, 0);
|
|
|
|
/*
|
|
* the stripe_pages, bio_pages, etc arrays point to the extra
|
|
* memory we allocated past the end of the rbio
|
|
*/
|
|
p = rbio + 1;
|
|
#define CONSUME_ALLOC(ptr, count) do { \
|
|
ptr = p; \
|
|
p = (unsigned char *)p + sizeof(*(ptr)) * (count); \
|
|
} while (0)
|
|
CONSUME_ALLOC(rbio->stripe_pages, num_pages);
|
|
CONSUME_ALLOC(rbio->bio_pages, num_pages);
|
|
CONSUME_ALLOC(rbio->finish_pointers, real_stripes);
|
|
CONSUME_ALLOC(rbio->dbitmap, BITS_TO_LONGS(stripe_npages));
|
|
CONSUME_ALLOC(rbio->finish_pbitmap, BITS_TO_LONGS(stripe_npages));
|
|
#undef CONSUME_ALLOC
|
|
|
|
if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID5)
|
|
nr_data = real_stripes - 1;
|
|
else if (bbio->map_type & BTRFS_BLOCK_GROUP_RAID6)
|
|
nr_data = real_stripes - 2;
|
|
else
|
|
BUG();
|
|
|
|
rbio->nr_data = nr_data;
|
|
return rbio;
|
|
}
|
|
|
|
/* allocate pages for all the stripes in the bio, including parity */
|
|
static int alloc_rbio_pages(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int i;
|
|
struct page *page;
|
|
|
|
for (i = 0; i < rbio->nr_pages; i++) {
|
|
if (rbio->stripe_pages[i])
|
|
continue;
|
|
page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
rbio->stripe_pages[i] = page;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* only allocate pages for p/q stripes */
|
|
static int alloc_rbio_parity_pages(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int i;
|
|
struct page *page;
|
|
|
|
i = rbio_stripe_page_index(rbio, rbio->nr_data, 0);
|
|
|
|
for (; i < rbio->nr_pages; i++) {
|
|
if (rbio->stripe_pages[i])
|
|
continue;
|
|
page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
rbio->stripe_pages[i] = page;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* add a single page from a specific stripe into our list of bios for IO
|
|
* this will try to merge into existing bios if possible, and returns
|
|
* zero if all went well.
|
|
*/
|
|
static int rbio_add_io_page(struct btrfs_raid_bio *rbio,
|
|
struct bio_list *bio_list,
|
|
struct page *page,
|
|
int stripe_nr,
|
|
unsigned long page_index,
|
|
unsigned long bio_max_len)
|
|
{
|
|
struct bio *last = bio_list->tail;
|
|
u64 last_end = 0;
|
|
int ret;
|
|
struct bio *bio;
|
|
struct btrfs_bio_stripe *stripe;
|
|
u64 disk_start;
|
|
|
|
stripe = &rbio->bbio->stripes[stripe_nr];
|
|
disk_start = stripe->physical + (page_index << PAGE_SHIFT);
|
|
|
|
/* if the device is missing, just fail this stripe */
|
|
if (!stripe->dev->bdev)
|
|
return fail_rbio_index(rbio, stripe_nr);
|
|
|
|
/* see if we can add this page onto our existing bio */
|
|
if (last) {
|
|
last_end = (u64)last->bi_iter.bi_sector << 9;
|
|
last_end += last->bi_iter.bi_size;
|
|
|
|
/*
|
|
* we can't merge these if they are from different
|
|
* devices or if they are not contiguous
|
|
*/
|
|
if (last_end == disk_start && stripe->dev->bdev &&
|
|
!last->bi_status &&
|
|
last->bi_disk == stripe->dev->bdev->bd_disk &&
|
|
last->bi_partno == stripe->dev->bdev->bd_partno) {
|
|
ret = bio_add_page(last, page, PAGE_SIZE, 0);
|
|
if (ret == PAGE_SIZE)
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* put a new bio on the list */
|
|
bio = btrfs_io_bio_alloc(bio_max_len >> PAGE_SHIFT ?: 1);
|
|
bio->bi_iter.bi_size = 0;
|
|
bio_set_dev(bio, stripe->dev->bdev);
|
|
bio->bi_iter.bi_sector = disk_start >> 9;
|
|
|
|
bio_add_page(bio, page, PAGE_SIZE, 0);
|
|
bio_list_add(bio_list, bio);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* while we're doing the read/modify/write cycle, we could
|
|
* have errors in reading pages off the disk. This checks
|
|
* for errors and if we're not able to read the page it'll
|
|
* trigger parity reconstruction. The rmw will be finished
|
|
* after we've reconstructed the failed stripes
|
|
*/
|
|
static void validate_rbio_for_rmw(struct btrfs_raid_bio *rbio)
|
|
{
|
|
if (rbio->faila >= 0 || rbio->failb >= 0) {
|
|
BUG_ON(rbio->faila == rbio->real_stripes - 1);
|
|
__raid56_parity_recover(rbio);
|
|
} else {
|
|
finish_rmw(rbio);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* helper function to walk our bio list and populate the bio_pages array with
|
|
* the result. This seems expensive, but it is faster than constantly
|
|
* searching through the bio list as we setup the IO in finish_rmw or stripe
|
|
* reconstruction.
|
|
*
|
|
* This must be called before you trust the answers from page_in_rbio
|
|
*/
|
|
static void index_rbio_pages(struct btrfs_raid_bio *rbio)
|
|
{
|
|
struct bio *bio;
|
|
u64 start;
|
|
unsigned long stripe_offset;
|
|
unsigned long page_index;
|
|
|
|
spin_lock_irq(&rbio->bio_list_lock);
|
|
bio_list_for_each(bio, &rbio->bio_list) {
|
|
struct bio_vec bvec;
|
|
struct bvec_iter iter;
|
|
int i = 0;
|
|
|
|
start = (u64)bio->bi_iter.bi_sector << 9;
|
|
stripe_offset = start - rbio->bbio->raid_map[0];
|
|
page_index = stripe_offset >> PAGE_SHIFT;
|
|
|
|
if (bio_flagged(bio, BIO_CLONED))
|
|
bio->bi_iter = btrfs_io_bio(bio)->iter;
|
|
|
|
bio_for_each_segment(bvec, bio, iter) {
|
|
rbio->bio_pages[page_index + i] = bvec.bv_page;
|
|
i++;
|
|
}
|
|
}
|
|
spin_unlock_irq(&rbio->bio_list_lock);
|
|
}
|
|
|
|
/*
|
|
* this is called from one of two situations. We either
|
|
* have a full stripe from the higher layers, or we've read all
|
|
* the missing bits off disk.
|
|
*
|
|
* This will calculate the parity and then send down any
|
|
* changed blocks.
|
|
*/
|
|
static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
|
|
{
|
|
struct btrfs_bio *bbio = rbio->bbio;
|
|
void **pointers = rbio->finish_pointers;
|
|
int nr_data = rbio->nr_data;
|
|
int stripe;
|
|
int pagenr;
|
|
bool has_qstripe;
|
|
struct bio_list bio_list;
|
|
struct bio *bio;
|
|
int ret;
|
|
|
|
bio_list_init(&bio_list);
|
|
|
|
if (rbio->real_stripes - rbio->nr_data == 1)
|
|
has_qstripe = false;
|
|
else if (rbio->real_stripes - rbio->nr_data == 2)
|
|
has_qstripe = true;
|
|
else
|
|
BUG();
|
|
|
|
/* We should have at least one data sector. */
|
|
ASSERT(bitmap_weight(rbio->dbitmap, rbio->stripe_npages));
|
|
|
|
/* at this point we either have a full stripe,
|
|
* or we've read the full stripe from the drive.
|
|
* recalculate the parity and write the new results.
|
|
*
|
|
* We're not allowed to add any new bios to the
|
|
* bio list here, anyone else that wants to
|
|
* change this stripe needs to do their own rmw.
|
|
*/
|
|
spin_lock_irq(&rbio->bio_list_lock);
|
|
set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
|
|
spin_unlock_irq(&rbio->bio_list_lock);
|
|
|
|
atomic_set(&rbio->error, 0);
|
|
|
|
/*
|
|
* now that we've set rmw_locked, run through the
|
|
* bio list one last time and map the page pointers
|
|
*
|
|
* We don't cache full rbios because we're assuming
|
|
* the higher layers are unlikely to use this area of
|
|
* the disk again soon. If they do use it again,
|
|
* hopefully they will send another full bio.
|
|
*/
|
|
index_rbio_pages(rbio);
|
|
if (!rbio_is_full(rbio))
|
|
cache_rbio_pages(rbio);
|
|
else
|
|
clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
|
|
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) {
|
|
struct page *p;
|
|
/* first collect one page from each data stripe */
|
|
for (stripe = 0; stripe < nr_data; stripe++) {
|
|
p = page_in_rbio(rbio, stripe, pagenr, 0);
|
|
pointers[stripe] = kmap(p);
|
|
}
|
|
|
|
/* then add the parity stripe */
|
|
p = rbio_pstripe_page(rbio, pagenr);
|
|
SetPageUptodate(p);
|
|
pointers[stripe++] = kmap(p);
|
|
|
|
if (has_qstripe) {
|
|
|
|
/*
|
|
* raid6, add the qstripe and call the
|
|
* library function to fill in our p/q
|
|
*/
|
|
p = rbio_qstripe_page(rbio, pagenr);
|
|
SetPageUptodate(p);
|
|
pointers[stripe++] = kmap(p);
|
|
|
|
raid6_call.gen_syndrome(rbio->real_stripes, PAGE_SIZE,
|
|
pointers);
|
|
} else {
|
|
/* raid5 */
|
|
copy_page(pointers[nr_data], pointers[0]);
|
|
run_xor(pointers + 1, nr_data - 1, PAGE_SIZE);
|
|
}
|
|
|
|
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++)
|
|
kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
|
|
}
|
|
|
|
/*
|
|
* time to start writing. Make bios for everything from the
|
|
* higher layers (the bio_list in our rbio) and our p/q. Ignore
|
|
* everything else.
|
|
*/
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) {
|
|
struct page *page;
|
|
|
|
/* This vertical stripe has no data, skip it. */
|
|
if (!test_bit(pagenr, rbio->dbitmap))
|
|
continue;
|
|
|
|
if (stripe < rbio->nr_data) {
|
|
page = page_in_rbio(rbio, stripe, pagenr, 1);
|
|
if (!page)
|
|
continue;
|
|
} else {
|
|
page = rbio_stripe_page(rbio, stripe, pagenr);
|
|
}
|
|
|
|
ret = rbio_add_io_page(rbio, &bio_list,
|
|
page, stripe, pagenr, rbio->stripe_len);
|
|
if (ret)
|
|
goto cleanup;
|
|
}
|
|
}
|
|
|
|
if (likely(!bbio->num_tgtdevs))
|
|
goto write_data;
|
|
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
|
|
if (!bbio->tgtdev_map[stripe])
|
|
continue;
|
|
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) {
|
|
struct page *page;
|
|
|
|
/* This vertical stripe has no data, skip it. */
|
|
if (!test_bit(pagenr, rbio->dbitmap))
|
|
continue;
|
|
|
|
if (stripe < rbio->nr_data) {
|
|
page = page_in_rbio(rbio, stripe, pagenr, 1);
|
|
if (!page)
|
|
continue;
|
|
} else {
|
|
page = rbio_stripe_page(rbio, stripe, pagenr);
|
|
}
|
|
|
|
ret = rbio_add_io_page(rbio, &bio_list, page,
|
|
rbio->bbio->tgtdev_map[stripe],
|
|
pagenr, rbio->stripe_len);
|
|
if (ret)
|
|
goto cleanup;
|
|
}
|
|
}
|
|
|
|
write_data:
|
|
atomic_set(&rbio->stripes_pending, bio_list_size(&bio_list));
|
|
BUG_ON(atomic_read(&rbio->stripes_pending) == 0);
|
|
|
|
while (1) {
|
|
bio = bio_list_pop(&bio_list);
|
|
if (!bio)
|
|
break;
|
|
|
|
bio->bi_private = rbio;
|
|
bio->bi_end_io = raid_write_end_io;
|
|
bio->bi_opf = REQ_OP_WRITE;
|
|
|
|
submit_bio(bio);
|
|
}
|
|
return;
|
|
|
|
cleanup:
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
|
|
while ((bio = bio_list_pop(&bio_list)))
|
|
bio_put(bio);
|
|
}
|
|
|
|
/*
|
|
* helper to find the stripe number for a given bio. Used to figure out which
|
|
* stripe has failed. This expects the bio to correspond to a physical disk,
|
|
* so it looks up based on physical sector numbers.
|
|
*/
|
|
static int find_bio_stripe(struct btrfs_raid_bio *rbio,
|
|
struct bio *bio)
|
|
{
|
|
u64 physical = bio->bi_iter.bi_sector;
|
|
u64 stripe_start;
|
|
int i;
|
|
struct btrfs_bio_stripe *stripe;
|
|
|
|
physical <<= 9;
|
|
|
|
for (i = 0; i < rbio->bbio->num_stripes; i++) {
|
|
stripe = &rbio->bbio->stripes[i];
|
|
stripe_start = stripe->physical;
|
|
if (physical >= stripe_start &&
|
|
physical < stripe_start + rbio->stripe_len &&
|
|
stripe->dev->bdev &&
|
|
bio->bi_disk == stripe->dev->bdev->bd_disk &&
|
|
bio->bi_partno == stripe->dev->bdev->bd_partno) {
|
|
return i;
|
|
}
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* helper to find the stripe number for a given
|
|
* bio (before mapping). Used to figure out which stripe has
|
|
* failed. This looks up based on logical block numbers.
|
|
*/
|
|
static int find_logical_bio_stripe(struct btrfs_raid_bio *rbio,
|
|
struct bio *bio)
|
|
{
|
|
u64 logical = bio->bi_iter.bi_sector;
|
|
u64 stripe_start;
|
|
int i;
|
|
|
|
logical <<= 9;
|
|
|
|
for (i = 0; i < rbio->nr_data; i++) {
|
|
stripe_start = rbio->bbio->raid_map[i];
|
|
if (logical >= stripe_start &&
|
|
logical < stripe_start + rbio->stripe_len) {
|
|
return i;
|
|
}
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* returns -EIO if we had too many failures
|
|
*/
|
|
static int fail_rbio_index(struct btrfs_raid_bio *rbio, int failed)
|
|
{
|
|
unsigned long flags;
|
|
int ret = 0;
|
|
|
|
spin_lock_irqsave(&rbio->bio_list_lock, flags);
|
|
|
|
/* we already know this stripe is bad, move on */
|
|
if (rbio->faila == failed || rbio->failb == failed)
|
|
goto out;
|
|
|
|
if (rbio->faila == -1) {
|
|
/* first failure on this rbio */
|
|
rbio->faila = failed;
|
|
atomic_inc(&rbio->error);
|
|
} else if (rbio->failb == -1) {
|
|
/* second failure on this rbio */
|
|
rbio->failb = failed;
|
|
atomic_inc(&rbio->error);
|
|
} else {
|
|
ret = -EIO;
|
|
}
|
|
out:
|
|
spin_unlock_irqrestore(&rbio->bio_list_lock, flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* helper to fail a stripe based on a physical disk
|
|
* bio.
|
|
*/
|
|
static int fail_bio_stripe(struct btrfs_raid_bio *rbio,
|
|
struct bio *bio)
|
|
{
|
|
int failed = find_bio_stripe(rbio, bio);
|
|
|
|
if (failed < 0)
|
|
return -EIO;
|
|
|
|
return fail_rbio_index(rbio, failed);
|
|
}
|
|
|
|
/*
|
|
* this sets each page in the bio uptodate. It should only be used on private
|
|
* rbio pages, nothing that comes in from the higher layers
|
|
*/
|
|
static void set_bio_pages_uptodate(struct bio *bio)
|
|
{
|
|
struct bio_vec *bvec;
|
|
struct bvec_iter_all iter_all;
|
|
|
|
ASSERT(!bio_flagged(bio, BIO_CLONED));
|
|
|
|
bio_for_each_segment_all(bvec, bio, iter_all)
|
|
SetPageUptodate(bvec->bv_page);
|
|
}
|
|
|
|
/*
|
|
* end io for the read phase of the rmw cycle. All the bios here are physical
|
|
* stripe bios we've read from the disk so we can recalculate the parity of the
|
|
* stripe.
|
|
*
|
|
* This will usually kick off finish_rmw once all the bios are read in, but it
|
|
* may trigger parity reconstruction if we had any errors along the way
|
|
*/
|
|
static void raid_rmw_end_io(struct bio *bio)
|
|
{
|
|
struct btrfs_raid_bio *rbio = bio->bi_private;
|
|
|
|
if (bio->bi_status)
|
|
fail_bio_stripe(rbio, bio);
|
|
else
|
|
set_bio_pages_uptodate(bio);
|
|
|
|
bio_put(bio);
|
|
|
|
if (!atomic_dec_and_test(&rbio->stripes_pending))
|
|
return;
|
|
|
|
if (atomic_read(&rbio->error) > rbio->bbio->max_errors)
|
|
goto cleanup;
|
|
|
|
/*
|
|
* this will normally call finish_rmw to start our write
|
|
* but if there are any failed stripes we'll reconstruct
|
|
* from parity first
|
|
*/
|
|
validate_rbio_for_rmw(rbio);
|
|
return;
|
|
|
|
cleanup:
|
|
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
}
|
|
|
|
/*
|
|
* the stripe must be locked by the caller. It will
|
|
* unlock after all the writes are done
|
|
*/
|
|
static int raid56_rmw_stripe(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int bios_to_read = 0;
|
|
struct bio_list bio_list;
|
|
int ret;
|
|
int pagenr;
|
|
int stripe;
|
|
struct bio *bio;
|
|
|
|
bio_list_init(&bio_list);
|
|
|
|
ret = alloc_rbio_pages(rbio);
|
|
if (ret)
|
|
goto cleanup;
|
|
|
|
index_rbio_pages(rbio);
|
|
|
|
atomic_set(&rbio->error, 0);
|
|
/*
|
|
* build a list of bios to read all the missing parts of this
|
|
* stripe
|
|
*/
|
|
for (stripe = 0; stripe < rbio->nr_data; stripe++) {
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) {
|
|
struct page *page;
|
|
/*
|
|
* we want to find all the pages missing from
|
|
* the rbio and read them from the disk. If
|
|
* page_in_rbio finds a page in the bio list
|
|
* we don't need to read it off the stripe.
|
|
*/
|
|
page = page_in_rbio(rbio, stripe, pagenr, 1);
|
|
if (page)
|
|
continue;
|
|
|
|
page = rbio_stripe_page(rbio, stripe, pagenr);
|
|
/*
|
|
* the bio cache may have handed us an uptodate
|
|
* page. If so, be happy and use it
|
|
*/
|
|
if (PageUptodate(page))
|
|
continue;
|
|
|
|
ret = rbio_add_io_page(rbio, &bio_list, page,
|
|
stripe, pagenr, rbio->stripe_len);
|
|
if (ret)
|
|
goto cleanup;
|
|
}
|
|
}
|
|
|
|
bios_to_read = bio_list_size(&bio_list);
|
|
if (!bios_to_read) {
|
|
/*
|
|
* this can happen if others have merged with
|
|
* us, it means there is nothing left to read.
|
|
* But if there are missing devices it may not be
|
|
* safe to do the full stripe write yet.
|
|
*/
|
|
goto finish;
|
|
}
|
|
|
|
/*
|
|
* the bbio may be freed once we submit the last bio. Make sure
|
|
* not to touch it after that
|
|
*/
|
|
atomic_set(&rbio->stripes_pending, bios_to_read);
|
|
while (1) {
|
|
bio = bio_list_pop(&bio_list);
|
|
if (!bio)
|
|
break;
|
|
|
|
bio->bi_private = rbio;
|
|
bio->bi_end_io = raid_rmw_end_io;
|
|
bio->bi_opf = REQ_OP_READ;
|
|
|
|
btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56);
|
|
|
|
submit_bio(bio);
|
|
}
|
|
/* the actual write will happen once the reads are done */
|
|
return 0;
|
|
|
|
cleanup:
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
|
|
while ((bio = bio_list_pop(&bio_list)))
|
|
bio_put(bio);
|
|
|
|
return -EIO;
|
|
|
|
finish:
|
|
validate_rbio_for_rmw(rbio);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* if the upper layers pass in a full stripe, we thank them by only allocating
|
|
* enough pages to hold the parity, and sending it all down quickly.
|
|
*/
|
|
static int full_stripe_write(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int ret;
|
|
|
|
ret = alloc_rbio_parity_pages(rbio);
|
|
if (ret) {
|
|
__free_raid_bio(rbio);
|
|
return ret;
|
|
}
|
|
|
|
ret = lock_stripe_add(rbio);
|
|
if (ret == 0)
|
|
finish_rmw(rbio);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* partial stripe writes get handed over to async helpers.
|
|
* We're really hoping to merge a few more writes into this
|
|
* rbio before calculating new parity
|
|
*/
|
|
static int partial_stripe_write(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int ret;
|
|
|
|
ret = lock_stripe_add(rbio);
|
|
if (ret == 0)
|
|
start_async_work(rbio, rmw_work);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* sometimes while we were reading from the drive to
|
|
* recalculate parity, enough new bios come into create
|
|
* a full stripe. So we do a check here to see if we can
|
|
* go directly to finish_rmw
|
|
*/
|
|
static int __raid56_parity_write(struct btrfs_raid_bio *rbio)
|
|
{
|
|
/* head off into rmw land if we don't have a full stripe */
|
|
if (!rbio_is_full(rbio))
|
|
return partial_stripe_write(rbio);
|
|
return full_stripe_write(rbio);
|
|
}
|
|
|
|
/*
|
|
* We use plugging call backs to collect full stripes.
|
|
* Any time we get a partial stripe write while plugged
|
|
* we collect it into a list. When the unplug comes down,
|
|
* we sort the list by logical block number and merge
|
|
* everything we can into the same rbios
|
|
*/
|
|
struct btrfs_plug_cb {
|
|
struct blk_plug_cb cb;
|
|
struct btrfs_fs_info *info;
|
|
struct list_head rbio_list;
|
|
struct btrfs_work work;
|
|
};
|
|
|
|
/*
|
|
* rbios on the plug list are sorted for easier merging.
|
|
*/
|
|
static int plug_cmp(void *priv, struct list_head *a, struct list_head *b)
|
|
{
|
|
struct btrfs_raid_bio *ra = container_of(a, struct btrfs_raid_bio,
|
|
plug_list);
|
|
struct btrfs_raid_bio *rb = container_of(b, struct btrfs_raid_bio,
|
|
plug_list);
|
|
u64 a_sector = ra->bio_list.head->bi_iter.bi_sector;
|
|
u64 b_sector = rb->bio_list.head->bi_iter.bi_sector;
|
|
|
|
if (a_sector < b_sector)
|
|
return -1;
|
|
if (a_sector > b_sector)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static void run_plug(struct btrfs_plug_cb *plug)
|
|
{
|
|
struct btrfs_raid_bio *cur;
|
|
struct btrfs_raid_bio *last = NULL;
|
|
|
|
/*
|
|
* sort our plug list then try to merge
|
|
* everything we can in hopes of creating full
|
|
* stripes.
|
|
*/
|
|
list_sort(NULL, &plug->rbio_list, plug_cmp);
|
|
while (!list_empty(&plug->rbio_list)) {
|
|
cur = list_entry(plug->rbio_list.next,
|
|
struct btrfs_raid_bio, plug_list);
|
|
list_del_init(&cur->plug_list);
|
|
|
|
if (rbio_is_full(cur)) {
|
|
int ret;
|
|
|
|
/* we have a full stripe, send it down */
|
|
ret = full_stripe_write(cur);
|
|
BUG_ON(ret);
|
|
continue;
|
|
}
|
|
if (last) {
|
|
if (rbio_can_merge(last, cur)) {
|
|
merge_rbio(last, cur);
|
|
__free_raid_bio(cur);
|
|
continue;
|
|
|
|
}
|
|
__raid56_parity_write(last);
|
|
}
|
|
last = cur;
|
|
}
|
|
if (last) {
|
|
__raid56_parity_write(last);
|
|
}
|
|
kfree(plug);
|
|
}
|
|
|
|
/*
|
|
* if the unplug comes from schedule, we have to push the
|
|
* work off to a helper thread
|
|
*/
|
|
static void unplug_work(struct btrfs_work *work)
|
|
{
|
|
struct btrfs_plug_cb *plug;
|
|
plug = container_of(work, struct btrfs_plug_cb, work);
|
|
run_plug(plug);
|
|
}
|
|
|
|
static void btrfs_raid_unplug(struct blk_plug_cb *cb, bool from_schedule)
|
|
{
|
|
struct btrfs_plug_cb *plug;
|
|
plug = container_of(cb, struct btrfs_plug_cb, cb);
|
|
|
|
if (from_schedule) {
|
|
btrfs_init_work(&plug->work, unplug_work, NULL, NULL);
|
|
btrfs_queue_work(plug->info->rmw_workers,
|
|
&plug->work);
|
|
return;
|
|
}
|
|
run_plug(plug);
|
|
}
|
|
|
|
/* Add the original bio into rbio->bio_list, and update rbio::dbitmap. */
|
|
static void rbio_add_bio(struct btrfs_raid_bio *rbio, struct bio *orig_bio)
|
|
{
|
|
const struct btrfs_fs_info *fs_info = rbio->fs_info;
|
|
const u64 orig_logical = orig_bio->bi_iter.bi_sector << SECTOR_SHIFT;
|
|
const u64 full_stripe_start = rbio->bbio->raid_map[0];
|
|
const u32 orig_len = orig_bio->bi_iter.bi_size;
|
|
const u32 sectorsize = fs_info->sectorsize;
|
|
u64 cur_logical;
|
|
|
|
ASSERT(orig_logical >= full_stripe_start &&
|
|
orig_logical + orig_len <= full_stripe_start +
|
|
rbio->nr_data * rbio->stripe_len);
|
|
|
|
bio_list_add(&rbio->bio_list, orig_bio);
|
|
rbio->bio_list_bytes += orig_bio->bi_iter.bi_size;
|
|
|
|
/* Update the dbitmap. */
|
|
for (cur_logical = orig_logical; cur_logical < orig_logical + orig_len;
|
|
cur_logical += sectorsize) {
|
|
int bit = ((u32)(cur_logical - full_stripe_start) >>
|
|
PAGE_SHIFT) % rbio->stripe_npages;
|
|
|
|
set_bit(bit, rbio->dbitmap);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* our main entry point for writes from the rest of the FS.
|
|
*/
|
|
int raid56_parity_write(struct btrfs_fs_info *fs_info, struct bio *bio,
|
|
struct btrfs_bio *bbio, u64 stripe_len)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
struct btrfs_plug_cb *plug = NULL;
|
|
struct blk_plug_cb *cb;
|
|
int ret;
|
|
|
|
rbio = alloc_rbio(fs_info, bbio, stripe_len);
|
|
if (IS_ERR(rbio)) {
|
|
btrfs_put_bbio(bbio);
|
|
return PTR_ERR(rbio);
|
|
}
|
|
rbio->operation = BTRFS_RBIO_WRITE;
|
|
rbio_add_bio(rbio, bio);
|
|
|
|
btrfs_bio_counter_inc_noblocked(fs_info);
|
|
rbio->generic_bio_cnt = 1;
|
|
|
|
/*
|
|
* don't plug on full rbios, just get them out the door
|
|
* as quickly as we can
|
|
*/
|
|
if (rbio_is_full(rbio)) {
|
|
ret = full_stripe_write(rbio);
|
|
if (ret)
|
|
btrfs_bio_counter_dec(fs_info);
|
|
return ret;
|
|
}
|
|
|
|
cb = blk_check_plugged(btrfs_raid_unplug, fs_info, sizeof(*plug));
|
|
if (cb) {
|
|
plug = container_of(cb, struct btrfs_plug_cb, cb);
|
|
if (!plug->info) {
|
|
plug->info = fs_info;
|
|
INIT_LIST_HEAD(&plug->rbio_list);
|
|
}
|
|
list_add_tail(&rbio->plug_list, &plug->rbio_list);
|
|
ret = 0;
|
|
} else {
|
|
ret = __raid56_parity_write(rbio);
|
|
if (ret)
|
|
btrfs_bio_counter_dec(fs_info);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* all parity reconstruction happens here. We've read in everything
|
|
* we can find from the drives and this does the heavy lifting of
|
|
* sorting the good from the bad.
|
|
*/
|
|
static void __raid_recover_end_io(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int pagenr, stripe;
|
|
void **pointers;
|
|
int faila = -1, failb = -1;
|
|
struct page *page;
|
|
blk_status_t err;
|
|
int i;
|
|
|
|
pointers = kcalloc(rbio->real_stripes, sizeof(void *), GFP_NOFS);
|
|
if (!pointers) {
|
|
err = BLK_STS_RESOURCE;
|
|
goto cleanup_io;
|
|
}
|
|
|
|
faila = rbio->faila;
|
|
failb = rbio->failb;
|
|
|
|
if (rbio->operation == BTRFS_RBIO_READ_REBUILD ||
|
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) {
|
|
spin_lock_irq(&rbio->bio_list_lock);
|
|
set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
|
|
spin_unlock_irq(&rbio->bio_list_lock);
|
|
}
|
|
|
|
index_rbio_pages(rbio);
|
|
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) {
|
|
/*
|
|
* Now we just use bitmap to mark the horizontal stripes in
|
|
* which we have data when doing parity scrub.
|
|
*/
|
|
if (rbio->operation == BTRFS_RBIO_PARITY_SCRUB &&
|
|
!test_bit(pagenr, rbio->dbitmap))
|
|
continue;
|
|
|
|
/* setup our array of pointers with pages
|
|
* from each stripe
|
|
*/
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
|
|
/*
|
|
* if we're rebuilding a read, we have to use
|
|
* pages from the bio list
|
|
*/
|
|
if ((rbio->operation == BTRFS_RBIO_READ_REBUILD ||
|
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) &&
|
|
(stripe == faila || stripe == failb)) {
|
|
page = page_in_rbio(rbio, stripe, pagenr, 0);
|
|
} else {
|
|
page = rbio_stripe_page(rbio, stripe, pagenr);
|
|
}
|
|
pointers[stripe] = kmap(page);
|
|
}
|
|
|
|
/* all raid6 handling here */
|
|
if (rbio->bbio->map_type & BTRFS_BLOCK_GROUP_RAID6) {
|
|
/*
|
|
* single failure, rebuild from parity raid5
|
|
* style
|
|
*/
|
|
if (failb < 0) {
|
|
if (faila == rbio->nr_data) {
|
|
/*
|
|
* Just the P stripe has failed, without
|
|
* a bad data or Q stripe.
|
|
* TODO, we should redo the xor here.
|
|
*/
|
|
err = BLK_STS_IOERR;
|
|
goto cleanup;
|
|
}
|
|
/*
|
|
* a single failure in raid6 is rebuilt
|
|
* in the pstripe code below
|
|
*/
|
|
goto pstripe;
|
|
}
|
|
|
|
/* make sure our ps and qs are in order */
|
|
if (faila > failb) {
|
|
int tmp = failb;
|
|
failb = faila;
|
|
faila = tmp;
|
|
}
|
|
|
|
/* if the q stripe is failed, do a pstripe reconstruction
|
|
* from the xors.
|
|
* If both the q stripe and the P stripe are failed, we're
|
|
* here due to a crc mismatch and we can't give them the
|
|
* data they want
|
|
*/
|
|
if (rbio->bbio->raid_map[failb] == RAID6_Q_STRIPE) {
|
|
if (rbio->bbio->raid_map[faila] ==
|
|
RAID5_P_STRIPE) {
|
|
err = BLK_STS_IOERR;
|
|
goto cleanup;
|
|
}
|
|
/*
|
|
* otherwise we have one bad data stripe and
|
|
* a good P stripe. raid5!
|
|
*/
|
|
goto pstripe;
|
|
}
|
|
|
|
if (rbio->bbio->raid_map[failb] == RAID5_P_STRIPE) {
|
|
raid6_datap_recov(rbio->real_stripes,
|
|
PAGE_SIZE, faila, pointers);
|
|
} else {
|
|
raid6_2data_recov(rbio->real_stripes,
|
|
PAGE_SIZE, faila, failb,
|
|
pointers);
|
|
}
|
|
} else {
|
|
void *p;
|
|
|
|
/* rebuild from P stripe here (raid5 or raid6) */
|
|
BUG_ON(failb != -1);
|
|
pstripe:
|
|
/* Copy parity block into failed block to start with */
|
|
copy_page(pointers[faila], pointers[rbio->nr_data]);
|
|
|
|
/* rearrange the pointer array */
|
|
p = pointers[faila];
|
|
for (stripe = faila; stripe < rbio->nr_data - 1; stripe++)
|
|
pointers[stripe] = pointers[stripe + 1];
|
|
pointers[rbio->nr_data - 1] = p;
|
|
|
|
/* xor in the rest */
|
|
run_xor(pointers, rbio->nr_data - 1, PAGE_SIZE);
|
|
}
|
|
/* if we're doing this rebuild as part of an rmw, go through
|
|
* and set all of our private rbio pages in the
|
|
* failed stripes as uptodate. This way finish_rmw will
|
|
* know they can be trusted. If this was a read reconstruction,
|
|
* other endio functions will fiddle the uptodate bits
|
|
*/
|
|
if (rbio->operation == BTRFS_RBIO_WRITE) {
|
|
for (i = 0; i < rbio->stripe_npages; i++) {
|
|
if (faila != -1) {
|
|
page = rbio_stripe_page(rbio, faila, i);
|
|
SetPageUptodate(page);
|
|
}
|
|
if (failb != -1) {
|
|
page = rbio_stripe_page(rbio, failb, i);
|
|
SetPageUptodate(page);
|
|
}
|
|
}
|
|
}
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
|
|
/*
|
|
* if we're rebuilding a read, we have to use
|
|
* pages from the bio list
|
|
*/
|
|
if ((rbio->operation == BTRFS_RBIO_READ_REBUILD ||
|
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) &&
|
|
(stripe == faila || stripe == failb)) {
|
|
page = page_in_rbio(rbio, stripe, pagenr, 0);
|
|
} else {
|
|
page = rbio_stripe_page(rbio, stripe, pagenr);
|
|
}
|
|
kunmap(page);
|
|
}
|
|
}
|
|
|
|
err = BLK_STS_OK;
|
|
cleanup:
|
|
kfree(pointers);
|
|
|
|
cleanup_io:
|
|
/*
|
|
* Similar to READ_REBUILD, REBUILD_MISSING at this point also has a
|
|
* valid rbio which is consistent with ondisk content, thus such a
|
|
* valid rbio can be cached to avoid further disk reads.
|
|
*/
|
|
if (rbio->operation == BTRFS_RBIO_READ_REBUILD ||
|
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING) {
|
|
/*
|
|
* - In case of two failures, where rbio->failb != -1:
|
|
*
|
|
* Do not cache this rbio since the above read reconstruction
|
|
* (raid6_datap_recov() or raid6_2data_recov()) may have
|
|
* changed some content of stripes which are not identical to
|
|
* on-disk content any more, otherwise, a later write/recover
|
|
* may steal stripe_pages from this rbio and end up with
|
|
* corruptions or rebuild failures.
|
|
*
|
|
* - In case of single failure, where rbio->failb == -1:
|
|
*
|
|
* Cache this rbio iff the above read reconstruction is
|
|
* executed without problems.
|
|
*/
|
|
if (err == BLK_STS_OK && rbio->failb < 0)
|
|
cache_rbio_pages(rbio);
|
|
else
|
|
clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
|
|
|
|
rbio_orig_end_io(rbio, err);
|
|
} else if (err == BLK_STS_OK) {
|
|
rbio->faila = -1;
|
|
rbio->failb = -1;
|
|
|
|
if (rbio->operation == BTRFS_RBIO_WRITE)
|
|
finish_rmw(rbio);
|
|
else if (rbio->operation == BTRFS_RBIO_PARITY_SCRUB)
|
|
finish_parity_scrub(rbio, 0);
|
|
else
|
|
BUG();
|
|
} else {
|
|
rbio_orig_end_io(rbio, err);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* This is called only for stripes we've read from disk to
|
|
* reconstruct the parity.
|
|
*/
|
|
static void raid_recover_end_io(struct bio *bio)
|
|
{
|
|
struct btrfs_raid_bio *rbio = bio->bi_private;
|
|
|
|
/*
|
|
* we only read stripe pages off the disk, set them
|
|
* up to date if there were no errors
|
|
*/
|
|
if (bio->bi_status)
|
|
fail_bio_stripe(rbio, bio);
|
|
else
|
|
set_bio_pages_uptodate(bio);
|
|
bio_put(bio);
|
|
|
|
if (!atomic_dec_and_test(&rbio->stripes_pending))
|
|
return;
|
|
|
|
if (atomic_read(&rbio->error) > rbio->bbio->max_errors)
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
else
|
|
__raid_recover_end_io(rbio);
|
|
}
|
|
|
|
/*
|
|
* reads everything we need off the disk to reconstruct
|
|
* the parity. endio handlers trigger final reconstruction
|
|
* when the IO is done.
|
|
*
|
|
* This is used both for reads from the higher layers and for
|
|
* parity construction required to finish a rmw cycle.
|
|
*/
|
|
static int __raid56_parity_recover(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int bios_to_read = 0;
|
|
struct bio_list bio_list;
|
|
int ret;
|
|
int pagenr;
|
|
int stripe;
|
|
struct bio *bio;
|
|
|
|
bio_list_init(&bio_list);
|
|
|
|
ret = alloc_rbio_pages(rbio);
|
|
if (ret)
|
|
goto cleanup;
|
|
|
|
atomic_set(&rbio->error, 0);
|
|
|
|
/*
|
|
* Read everything that hasn't failed. However this time we will
|
|
* not trust any cached sector.
|
|
* As we may read out some stale data but higher layer is not reading
|
|
* that stale part.
|
|
*
|
|
* So here we always re-read everything in recovery path.
|
|
*/
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
|
|
if (rbio->faila == stripe || rbio->failb == stripe) {
|
|
atomic_inc(&rbio->error);
|
|
continue;
|
|
}
|
|
|
|
for (pagenr = 0; pagenr < rbio->stripe_npages; pagenr++) {
|
|
ret = rbio_add_io_page(rbio, &bio_list,
|
|
rbio_stripe_page(rbio, stripe, pagenr),
|
|
stripe, pagenr, rbio->stripe_len);
|
|
if (ret < 0)
|
|
goto cleanup;
|
|
}
|
|
}
|
|
|
|
bios_to_read = bio_list_size(&bio_list);
|
|
if (!bios_to_read) {
|
|
/*
|
|
* we might have no bios to read just because the pages
|
|
* were up to date, or we might have no bios to read because
|
|
* the devices were gone.
|
|
*/
|
|
if (atomic_read(&rbio->error) <= rbio->bbio->max_errors) {
|
|
__raid_recover_end_io(rbio);
|
|
goto out;
|
|
} else {
|
|
goto cleanup;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* the bbio may be freed once we submit the last bio. Make sure
|
|
* not to touch it after that
|
|
*/
|
|
atomic_set(&rbio->stripes_pending, bios_to_read);
|
|
while (1) {
|
|
bio = bio_list_pop(&bio_list);
|
|
if (!bio)
|
|
break;
|
|
|
|
bio->bi_private = rbio;
|
|
bio->bi_end_io = raid_recover_end_io;
|
|
bio->bi_opf = REQ_OP_READ;
|
|
|
|
btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56);
|
|
|
|
submit_bio(bio);
|
|
}
|
|
out:
|
|
return 0;
|
|
|
|
cleanup:
|
|
if (rbio->operation == BTRFS_RBIO_READ_REBUILD ||
|
|
rbio->operation == BTRFS_RBIO_REBUILD_MISSING)
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
|
|
while ((bio = bio_list_pop(&bio_list)))
|
|
bio_put(bio);
|
|
|
|
return -EIO;
|
|
}
|
|
|
|
/*
|
|
* the main entry point for reads from the higher layers. This
|
|
* is really only called when the normal read path had a failure,
|
|
* so we assume the bio they send down corresponds to a failed part
|
|
* of the drive.
|
|
*/
|
|
int raid56_parity_recover(struct btrfs_fs_info *fs_info, struct bio *bio,
|
|
struct btrfs_bio *bbio, u64 stripe_len,
|
|
int mirror_num, int generic_io)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
int ret;
|
|
|
|
if (generic_io) {
|
|
ASSERT(bbio->mirror_num == mirror_num);
|
|
btrfs_io_bio(bio)->mirror_num = mirror_num;
|
|
}
|
|
|
|
rbio = alloc_rbio(fs_info, bbio, stripe_len);
|
|
if (IS_ERR(rbio)) {
|
|
if (generic_io)
|
|
btrfs_put_bbio(bbio);
|
|
return PTR_ERR(rbio);
|
|
}
|
|
|
|
rbio->operation = BTRFS_RBIO_READ_REBUILD;
|
|
rbio_add_bio(rbio, bio);
|
|
|
|
rbio->faila = find_logical_bio_stripe(rbio, bio);
|
|
if (rbio->faila == -1) {
|
|
btrfs_warn(fs_info,
|
|
"%s could not find the bad stripe in raid56 so that we cannot recover any more (bio has logical %llu len %llu, bbio has map_type %llu)",
|
|
__func__, (u64)bio->bi_iter.bi_sector << 9,
|
|
(u64)bio->bi_iter.bi_size, bbio->map_type);
|
|
if (generic_io)
|
|
btrfs_put_bbio(bbio);
|
|
kfree(rbio);
|
|
return -EIO;
|
|
}
|
|
|
|
if (generic_io) {
|
|
btrfs_bio_counter_inc_noblocked(fs_info);
|
|
rbio->generic_bio_cnt = 1;
|
|
} else {
|
|
btrfs_get_bbio(bbio);
|
|
}
|
|
|
|
/*
|
|
* Loop retry:
|
|
* for 'mirror == 2', reconstruct from all other stripes.
|
|
* for 'mirror_num > 2', select a stripe to fail on every retry.
|
|
*/
|
|
if (mirror_num > 2) {
|
|
/*
|
|
* 'mirror == 3' is to fail the p stripe and
|
|
* reconstruct from the q stripe. 'mirror > 3' is to
|
|
* fail a data stripe and reconstruct from p+q stripe.
|
|
*/
|
|
rbio->failb = rbio->real_stripes - (mirror_num - 1);
|
|
ASSERT(rbio->failb > 0);
|
|
if (rbio->failb <= rbio->faila)
|
|
rbio->failb--;
|
|
}
|
|
|
|
ret = lock_stripe_add(rbio);
|
|
|
|
/*
|
|
* __raid56_parity_recover will end the bio with
|
|
* any errors it hits. We don't want to return
|
|
* its error value up the stack because our caller
|
|
* will end up calling bio_endio with any nonzero
|
|
* return
|
|
*/
|
|
if (ret == 0)
|
|
__raid56_parity_recover(rbio);
|
|
/*
|
|
* our rbio has been added to the list of
|
|
* rbios that will be handled after the
|
|
* currently lock owner is done
|
|
*/
|
|
return 0;
|
|
|
|
}
|
|
|
|
static void rmw_work(struct btrfs_work *work)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
|
|
rbio = container_of(work, struct btrfs_raid_bio, work);
|
|
raid56_rmw_stripe(rbio);
|
|
}
|
|
|
|
static void read_rebuild_work(struct btrfs_work *work)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
|
|
rbio = container_of(work, struct btrfs_raid_bio, work);
|
|
__raid56_parity_recover(rbio);
|
|
}
|
|
|
|
/*
|
|
* The following code is used to scrub/replace the parity stripe
|
|
*
|
|
* Caller must have already increased bio_counter for getting @bbio.
|
|
*
|
|
* Note: We need make sure all the pages that add into the scrub/replace
|
|
* raid bio are correct and not be changed during the scrub/replace. That
|
|
* is those pages just hold metadata or file data with checksum.
|
|
*/
|
|
|
|
struct btrfs_raid_bio *
|
|
raid56_parity_alloc_scrub_rbio(struct btrfs_fs_info *fs_info, struct bio *bio,
|
|
struct btrfs_bio *bbio, u64 stripe_len,
|
|
struct btrfs_device *scrub_dev,
|
|
unsigned long *dbitmap, int stripe_nsectors)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
int i;
|
|
|
|
rbio = alloc_rbio(fs_info, bbio, stripe_len);
|
|
if (IS_ERR(rbio))
|
|
return NULL;
|
|
bio_list_add(&rbio->bio_list, bio);
|
|
/*
|
|
* This is a special bio which is used to hold the completion handler
|
|
* and make the scrub rbio is similar to the other types
|
|
*/
|
|
ASSERT(!bio->bi_iter.bi_size);
|
|
rbio->operation = BTRFS_RBIO_PARITY_SCRUB;
|
|
|
|
/*
|
|
* After mapping bbio with BTRFS_MAP_WRITE, parities have been sorted
|
|
* to the end position, so this search can start from the first parity
|
|
* stripe.
|
|
*/
|
|
for (i = rbio->nr_data; i < rbio->real_stripes; i++) {
|
|
if (bbio->stripes[i].dev == scrub_dev) {
|
|
rbio->scrubp = i;
|
|
break;
|
|
}
|
|
}
|
|
ASSERT(i < rbio->real_stripes);
|
|
|
|
/* Now we just support the sectorsize equals to page size */
|
|
ASSERT(fs_info->sectorsize == PAGE_SIZE);
|
|
ASSERT(rbio->stripe_npages == stripe_nsectors);
|
|
bitmap_copy(rbio->dbitmap, dbitmap, stripe_nsectors);
|
|
|
|
/*
|
|
* We have already increased bio_counter when getting bbio, record it
|
|
* so we can free it at rbio_orig_end_io().
|
|
*/
|
|
rbio->generic_bio_cnt = 1;
|
|
|
|
return rbio;
|
|
}
|
|
|
|
/* Used for both parity scrub and missing. */
|
|
void raid56_add_scrub_pages(struct btrfs_raid_bio *rbio, struct page *page,
|
|
u64 logical)
|
|
{
|
|
int stripe_offset;
|
|
int index;
|
|
|
|
ASSERT(logical >= rbio->bbio->raid_map[0]);
|
|
ASSERT(logical + PAGE_SIZE <= rbio->bbio->raid_map[0] +
|
|
rbio->stripe_len * rbio->nr_data);
|
|
stripe_offset = (int)(logical - rbio->bbio->raid_map[0]);
|
|
index = stripe_offset >> PAGE_SHIFT;
|
|
rbio->bio_pages[index] = page;
|
|
}
|
|
|
|
/*
|
|
* We just scrub the parity that we have correct data on the same horizontal,
|
|
* so we needn't allocate all pages for all the stripes.
|
|
*/
|
|
static int alloc_rbio_essential_pages(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int i;
|
|
int bit;
|
|
int index;
|
|
struct page *page;
|
|
|
|
for_each_set_bit(bit, rbio->dbitmap, rbio->stripe_npages) {
|
|
for (i = 0; i < rbio->real_stripes; i++) {
|
|
index = i * rbio->stripe_npages + bit;
|
|
if (rbio->stripe_pages[index])
|
|
continue;
|
|
|
|
page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
|
if (!page)
|
|
return -ENOMEM;
|
|
rbio->stripe_pages[index] = page;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio,
|
|
int need_check)
|
|
{
|
|
struct btrfs_bio *bbio = rbio->bbio;
|
|
void **pointers = rbio->finish_pointers;
|
|
unsigned long *pbitmap = rbio->finish_pbitmap;
|
|
int nr_data = rbio->nr_data;
|
|
int stripe;
|
|
int pagenr;
|
|
bool has_qstripe;
|
|
struct page *p_page = NULL;
|
|
struct page *q_page = NULL;
|
|
struct bio_list bio_list;
|
|
struct bio *bio;
|
|
int is_replace = 0;
|
|
int ret;
|
|
|
|
bio_list_init(&bio_list);
|
|
|
|
if (rbio->real_stripes - rbio->nr_data == 1)
|
|
has_qstripe = false;
|
|
else if (rbio->real_stripes - rbio->nr_data == 2)
|
|
has_qstripe = true;
|
|
else
|
|
BUG();
|
|
|
|
if (bbio->num_tgtdevs && bbio->tgtdev_map[rbio->scrubp]) {
|
|
is_replace = 1;
|
|
bitmap_copy(pbitmap, rbio->dbitmap, rbio->stripe_npages);
|
|
}
|
|
|
|
/*
|
|
* Because the higher layers(scrubber) are unlikely to
|
|
* use this area of the disk again soon, so don't cache
|
|
* it.
|
|
*/
|
|
clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);
|
|
|
|
if (!need_check)
|
|
goto writeback;
|
|
|
|
p_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
|
if (!p_page)
|
|
goto cleanup;
|
|
SetPageUptodate(p_page);
|
|
|
|
if (has_qstripe) {
|
|
/* RAID6, allocate and map temp space for the Q stripe */
|
|
q_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM);
|
|
if (!q_page) {
|
|
__free_page(p_page);
|
|
goto cleanup;
|
|
}
|
|
SetPageUptodate(q_page);
|
|
pointers[rbio->real_stripes - 1] = kmap(q_page);
|
|
}
|
|
|
|
atomic_set(&rbio->error, 0);
|
|
|
|
/* Map the parity stripe just once */
|
|
pointers[nr_data] = kmap(p_page);
|
|
|
|
for_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) {
|
|
struct page *p;
|
|
void *parity;
|
|
/* first collect one page from each data stripe */
|
|
for (stripe = 0; stripe < nr_data; stripe++) {
|
|
p = page_in_rbio(rbio, stripe, pagenr, 0);
|
|
pointers[stripe] = kmap(p);
|
|
}
|
|
|
|
if (has_qstripe) {
|
|
/* RAID6, call the library function to fill in our P/Q */
|
|
raid6_call.gen_syndrome(rbio->real_stripes, PAGE_SIZE,
|
|
pointers);
|
|
} else {
|
|
/* raid5 */
|
|
copy_page(pointers[nr_data], pointers[0]);
|
|
run_xor(pointers + 1, nr_data - 1, PAGE_SIZE);
|
|
}
|
|
|
|
/* Check scrubbing parity and repair it */
|
|
p = rbio_stripe_page(rbio, rbio->scrubp, pagenr);
|
|
parity = kmap(p);
|
|
if (memcmp(parity, pointers[rbio->scrubp], PAGE_SIZE))
|
|
copy_page(parity, pointers[rbio->scrubp]);
|
|
else
|
|
/* Parity is right, needn't writeback */
|
|
bitmap_clear(rbio->dbitmap, pagenr, 1);
|
|
kunmap(p);
|
|
|
|
for (stripe = 0; stripe < nr_data; stripe++)
|
|
kunmap(page_in_rbio(rbio, stripe, pagenr, 0));
|
|
}
|
|
|
|
kunmap(p_page);
|
|
__free_page(p_page);
|
|
if (q_page) {
|
|
kunmap(q_page);
|
|
__free_page(q_page);
|
|
}
|
|
|
|
writeback:
|
|
/*
|
|
* time to start writing. Make bios for everything from the
|
|
* higher layers (the bio_list in our rbio) and our p/q. Ignore
|
|
* everything else.
|
|
*/
|
|
for_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) {
|
|
struct page *page;
|
|
|
|
page = rbio_stripe_page(rbio, rbio->scrubp, pagenr);
|
|
ret = rbio_add_io_page(rbio, &bio_list,
|
|
page, rbio->scrubp, pagenr, rbio->stripe_len);
|
|
if (ret)
|
|
goto cleanup;
|
|
}
|
|
|
|
if (!is_replace)
|
|
goto submit_write;
|
|
|
|
for_each_set_bit(pagenr, pbitmap, rbio->stripe_npages) {
|
|
struct page *page;
|
|
|
|
page = rbio_stripe_page(rbio, rbio->scrubp, pagenr);
|
|
ret = rbio_add_io_page(rbio, &bio_list, page,
|
|
bbio->tgtdev_map[rbio->scrubp],
|
|
pagenr, rbio->stripe_len);
|
|
if (ret)
|
|
goto cleanup;
|
|
}
|
|
|
|
submit_write:
|
|
nr_data = bio_list_size(&bio_list);
|
|
if (!nr_data) {
|
|
/* Every parity is right */
|
|
rbio_orig_end_io(rbio, BLK_STS_OK);
|
|
return;
|
|
}
|
|
|
|
atomic_set(&rbio->stripes_pending, nr_data);
|
|
|
|
while (1) {
|
|
bio = bio_list_pop(&bio_list);
|
|
if (!bio)
|
|
break;
|
|
|
|
bio->bi_private = rbio;
|
|
bio->bi_end_io = raid_write_end_io;
|
|
bio->bi_opf = REQ_OP_WRITE;
|
|
|
|
submit_bio(bio);
|
|
}
|
|
return;
|
|
|
|
cleanup:
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
|
|
while ((bio = bio_list_pop(&bio_list)))
|
|
bio_put(bio);
|
|
}
|
|
|
|
static inline int is_data_stripe(struct btrfs_raid_bio *rbio, int stripe)
|
|
{
|
|
if (stripe >= 0 && stripe < rbio->nr_data)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* While we're doing the parity check and repair, we could have errors
|
|
* in reading pages off the disk. This checks for errors and if we're
|
|
* not able to read the page it'll trigger parity reconstruction. The
|
|
* parity scrub will be finished after we've reconstructed the failed
|
|
* stripes
|
|
*/
|
|
static void validate_rbio_for_parity_scrub(struct btrfs_raid_bio *rbio)
|
|
{
|
|
if (atomic_read(&rbio->error) > rbio->bbio->max_errors)
|
|
goto cleanup;
|
|
|
|
if (rbio->faila >= 0 || rbio->failb >= 0) {
|
|
int dfail = 0, failp = -1;
|
|
|
|
if (is_data_stripe(rbio, rbio->faila))
|
|
dfail++;
|
|
else if (is_parity_stripe(rbio->faila))
|
|
failp = rbio->faila;
|
|
|
|
if (is_data_stripe(rbio, rbio->failb))
|
|
dfail++;
|
|
else if (is_parity_stripe(rbio->failb))
|
|
failp = rbio->failb;
|
|
|
|
/*
|
|
* Because we can not use a scrubbing parity to repair
|
|
* the data, so the capability of the repair is declined.
|
|
* (In the case of RAID5, we can not repair anything)
|
|
*/
|
|
if (dfail > rbio->bbio->max_errors - 1)
|
|
goto cleanup;
|
|
|
|
/*
|
|
* If all data is good, only parity is correctly, just
|
|
* repair the parity.
|
|
*/
|
|
if (dfail == 0) {
|
|
finish_parity_scrub(rbio, 0);
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Here means we got one corrupted data stripe and one
|
|
* corrupted parity on RAID6, if the corrupted parity
|
|
* is scrubbing parity, luckily, use the other one to repair
|
|
* the data, or we can not repair the data stripe.
|
|
*/
|
|
if (failp != rbio->scrubp)
|
|
goto cleanup;
|
|
|
|
__raid_recover_end_io(rbio);
|
|
} else {
|
|
finish_parity_scrub(rbio, 1);
|
|
}
|
|
return;
|
|
|
|
cleanup:
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
}
|
|
|
|
/*
|
|
* end io for the read phase of the rmw cycle. All the bios here are physical
|
|
* stripe bios we've read from the disk so we can recalculate the parity of the
|
|
* stripe.
|
|
*
|
|
* This will usually kick off finish_rmw once all the bios are read in, but it
|
|
* may trigger parity reconstruction if we had any errors along the way
|
|
*/
|
|
static void raid56_parity_scrub_end_io(struct bio *bio)
|
|
{
|
|
struct btrfs_raid_bio *rbio = bio->bi_private;
|
|
|
|
if (bio->bi_status)
|
|
fail_bio_stripe(rbio, bio);
|
|
else
|
|
set_bio_pages_uptodate(bio);
|
|
|
|
bio_put(bio);
|
|
|
|
if (!atomic_dec_and_test(&rbio->stripes_pending))
|
|
return;
|
|
|
|
/*
|
|
* this will normally call finish_rmw to start our write
|
|
* but if there are any failed stripes we'll reconstruct
|
|
* from parity first
|
|
*/
|
|
validate_rbio_for_parity_scrub(rbio);
|
|
}
|
|
|
|
static void raid56_parity_scrub_stripe(struct btrfs_raid_bio *rbio)
|
|
{
|
|
int bios_to_read = 0;
|
|
struct bio_list bio_list;
|
|
int ret;
|
|
int pagenr;
|
|
int stripe;
|
|
struct bio *bio;
|
|
|
|
bio_list_init(&bio_list);
|
|
|
|
ret = alloc_rbio_essential_pages(rbio);
|
|
if (ret)
|
|
goto cleanup;
|
|
|
|
atomic_set(&rbio->error, 0);
|
|
/*
|
|
* build a list of bios to read all the missing parts of this
|
|
* stripe
|
|
*/
|
|
for (stripe = 0; stripe < rbio->real_stripes; stripe++) {
|
|
for_each_set_bit(pagenr, rbio->dbitmap, rbio->stripe_npages) {
|
|
struct page *page;
|
|
/*
|
|
* we want to find all the pages missing from
|
|
* the rbio and read them from the disk. If
|
|
* page_in_rbio finds a page in the bio list
|
|
* we don't need to read it off the stripe.
|
|
*/
|
|
page = page_in_rbio(rbio, stripe, pagenr, 1);
|
|
if (page)
|
|
continue;
|
|
|
|
page = rbio_stripe_page(rbio, stripe, pagenr);
|
|
/*
|
|
* the bio cache may have handed us an uptodate
|
|
* page. If so, be happy and use it
|
|
*/
|
|
if (PageUptodate(page))
|
|
continue;
|
|
|
|
ret = rbio_add_io_page(rbio, &bio_list, page,
|
|
stripe, pagenr, rbio->stripe_len);
|
|
if (ret)
|
|
goto cleanup;
|
|
}
|
|
}
|
|
|
|
bios_to_read = bio_list_size(&bio_list);
|
|
if (!bios_to_read) {
|
|
/*
|
|
* this can happen if others have merged with
|
|
* us, it means there is nothing left to read.
|
|
* But if there are missing devices it may not be
|
|
* safe to do the full stripe write yet.
|
|
*/
|
|
goto finish;
|
|
}
|
|
|
|
/*
|
|
* the bbio may be freed once we submit the last bio. Make sure
|
|
* not to touch it after that
|
|
*/
|
|
atomic_set(&rbio->stripes_pending, bios_to_read);
|
|
while (1) {
|
|
bio = bio_list_pop(&bio_list);
|
|
if (!bio)
|
|
break;
|
|
|
|
bio->bi_private = rbio;
|
|
bio->bi_end_io = raid56_parity_scrub_end_io;
|
|
bio->bi_opf = REQ_OP_READ;
|
|
|
|
btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56);
|
|
|
|
submit_bio(bio);
|
|
}
|
|
/* the actual write will happen once the reads are done */
|
|
return;
|
|
|
|
cleanup:
|
|
rbio_orig_end_io(rbio, BLK_STS_IOERR);
|
|
|
|
while ((bio = bio_list_pop(&bio_list)))
|
|
bio_put(bio);
|
|
|
|
return;
|
|
|
|
finish:
|
|
validate_rbio_for_parity_scrub(rbio);
|
|
}
|
|
|
|
static void scrub_parity_work(struct btrfs_work *work)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
|
|
rbio = container_of(work, struct btrfs_raid_bio, work);
|
|
raid56_parity_scrub_stripe(rbio);
|
|
}
|
|
|
|
void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio)
|
|
{
|
|
if (!lock_stripe_add(rbio))
|
|
start_async_work(rbio, scrub_parity_work);
|
|
}
|
|
|
|
/* The following code is used for dev replace of a missing RAID 5/6 device. */
|
|
|
|
struct btrfs_raid_bio *
|
|
raid56_alloc_missing_rbio(struct btrfs_fs_info *fs_info, struct bio *bio,
|
|
struct btrfs_bio *bbio, u64 length)
|
|
{
|
|
struct btrfs_raid_bio *rbio;
|
|
|
|
rbio = alloc_rbio(fs_info, bbio, length);
|
|
if (IS_ERR(rbio))
|
|
return NULL;
|
|
|
|
rbio->operation = BTRFS_RBIO_REBUILD_MISSING;
|
|
bio_list_add(&rbio->bio_list, bio);
|
|
/*
|
|
* This is a special bio which is used to hold the completion handler
|
|
* and make the scrub rbio is similar to the other types
|
|
*/
|
|
ASSERT(!bio->bi_iter.bi_size);
|
|
|
|
rbio->faila = find_logical_bio_stripe(rbio, bio);
|
|
if (rbio->faila == -1) {
|
|
BUG();
|
|
kfree(rbio);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* When we get bbio, we have already increased bio_counter, record it
|
|
* so we can free it at rbio_orig_end_io()
|
|
*/
|
|
rbio->generic_bio_cnt = 1;
|
|
|
|
return rbio;
|
|
}
|
|
|
|
void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio)
|
|
{
|
|
if (!lock_stripe_add(rbio))
|
|
start_async_work(rbio, read_rebuild_work);
|
|
}
|