From af8e2d1df9848b39dd86b1e696bf8781d2020a88 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Thu, 23 Oct 2014 14:42:50 +0800 Subject: Btrfs, scrub: repair the common data on RAID5/6 if it is corrupted This patch implement the RAID5/6 common data repair function, the implementation is similar to the scrub on the other RAID such as RAID1, the differentia is that we don't read the data from the mirror, we use the data repair function of RAID5/6. Signed-off-by: Miao Xie --- fs/btrfs/scrub.c | 194 +++++++++++++++++++++++++++++++++++++++++++++++++------ 1 file changed, 176 insertions(+), 18 deletions(-) (limited to 'fs/btrfs/scrub.c') diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index efa083113827..ca4b9eb8b5da 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -63,6 +63,13 @@ struct scrub_ctx; */ #define SCRUB_MAX_PAGES_PER_BLOCK 16 /* 64k per node/leaf/sector */ +struct scrub_recover { + atomic_t refs; + struct btrfs_bio *bbio; + u64 *raid_map; + u64 map_length; +}; + struct scrub_page { struct scrub_block *sblock; struct page *page; @@ -79,6 +86,8 @@ struct scrub_page { unsigned int io_error:1; }; u8 csum[BTRFS_CSUM_SIZE]; + + struct scrub_recover *recover; }; struct scrub_bio { @@ -196,7 +205,7 @@ static int scrub_setup_recheck_block(struct scrub_ctx *sctx, static void scrub_recheck_block(struct btrfs_fs_info *fs_info, struct scrub_block *sblock, int is_metadata, int have_csum, u8 *csum, u64 generation, - u16 csum_size); + u16 csum_size, int retry_failed_mirror); static void scrub_recheck_block_checksum(struct btrfs_fs_info *fs_info, struct scrub_block *sblock, int is_metadata, int have_csum, @@ -790,6 +799,20 @@ out: scrub_pending_trans_workers_dec(sctx); } +static inline void scrub_get_recover(struct scrub_recover *recover) +{ + atomic_inc(&recover->refs); +} + +static inline void scrub_put_recover(struct scrub_recover *recover) +{ + if (atomic_dec_and_test(&recover->refs)) { + kfree(recover->bbio); + kfree(recover->raid_map); + kfree(recover); + } +} + /* * scrub_handle_errored_block gets called when either verification of the * pages failed or the bio failed to read, e.g. with EIO. In the latter @@ -906,7 +929,7 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check) /* build and submit the bios for the failed mirror, check checksums */ scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum, - csum, generation, sctx->csum_size); + csum, generation, sctx->csum_size, 1); if (!sblock_bad->header_error && !sblock_bad->checksum_error && sblock_bad->no_io_error_seen) { @@ -1019,7 +1042,7 @@ nodatasum_case: /* build and submit the bios, check checksums */ scrub_recheck_block(fs_info, sblock_other, is_metadata, have_csum, csum, generation, - sctx->csum_size); + sctx->csum_size, 0); if (!sblock_other->header_error && !sblock_other->checksum_error && @@ -1169,7 +1192,7 @@ nodatasum_case: */ scrub_recheck_block(fs_info, sblock_bad, is_metadata, have_csum, csum, - generation, sctx->csum_size); + generation, sctx->csum_size, 1); if (!sblock_bad->header_error && !sblock_bad->checksum_error && sblock_bad->no_io_error_seen) @@ -1201,11 +1224,18 @@ out: mirror_index++) { struct scrub_block *sblock = sblocks_for_recheck + mirror_index; + struct scrub_recover *recover; int page_index; for (page_index = 0; page_index < sblock->page_count; page_index++) { sblock->pagev[page_index]->sblock = NULL; + recover = sblock->pagev[page_index]->recover; + if (recover) { + scrub_put_recover(recover); + sblock->pagev[page_index]->recover = + NULL; + } scrub_page_put(sblock->pagev[page_index]); } } @@ -1215,14 +1245,63 @@ out: return 0; } +static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio, u64 *raid_map) +{ + if (raid_map) { + if (raid_map[bbio->num_stripes - 1] == RAID6_Q_STRIPE) + return 3; + else + return 2; + } else { + return (int)bbio->num_stripes; + } +} + +static inline void scrub_stripe_index_and_offset(u64 logical, u64 *raid_map, + u64 mapped_length, + int nstripes, int mirror, + int *stripe_index, + u64 *stripe_offset) +{ + int i; + + if (raid_map) { + /* RAID5/6 */ + for (i = 0; i < nstripes; i++) { + if (raid_map[i] == RAID6_Q_STRIPE || + raid_map[i] == RAID5_P_STRIPE) + continue; + + if (logical >= raid_map[i] && + logical < raid_map[i] + mapped_length) + break; + } + + *stripe_index = i; + *stripe_offset = logical - raid_map[i]; + } else { + /* The other RAID type */ + *stripe_index = mirror; + *stripe_offset = 0; + } +} + static int scrub_setup_recheck_block(struct scrub_ctx *sctx, struct btrfs_fs_info *fs_info, struct scrub_block *original_sblock, u64 length, u64 logical, struct scrub_block *sblocks_for_recheck) { + struct scrub_recover *recover; + struct btrfs_bio *bbio; + u64 *raid_map; + u64 sublen; + u64 mapped_length; + u64 stripe_offset; + int stripe_index; int page_index; int mirror_index; + int nmirrors; int ret; /* @@ -1233,23 +1312,39 @@ static int scrub_setup_recheck_block(struct scrub_ctx *sctx, page_index = 0; while (length > 0) { - u64 sublen = min_t(u64, length, PAGE_SIZE); - u64 mapped_length = sublen; - struct btrfs_bio *bbio = NULL; + sublen = min_t(u64, length, PAGE_SIZE); + mapped_length = sublen; + bbio = NULL; + raid_map = NULL; /* * with a length of PAGE_SIZE, each returned stripe * represents one mirror */ - ret = btrfs_map_block(fs_info, REQ_GET_READ_MIRRORS, logical, - &mapped_length, &bbio, 0); + ret = btrfs_map_sblock(fs_info, REQ_GET_READ_MIRRORS, logical, + &mapped_length, &bbio, 0, &raid_map); if (ret || !bbio || mapped_length < sublen) { kfree(bbio); + kfree(raid_map); return -EIO; } + recover = kzalloc(sizeof(struct scrub_recover), GFP_NOFS); + if (!recover) { + kfree(bbio); + kfree(raid_map); + return -ENOMEM; + } + + atomic_set(&recover->refs, 1); + recover->bbio = bbio; + recover->raid_map = raid_map; + recover->map_length = mapped_length; + BUG_ON(page_index >= SCRUB_PAGES_PER_RD_BIO); - for (mirror_index = 0; mirror_index < (int)bbio->num_stripes; + + nmirrors = scrub_nr_raid_mirrors(bbio, raid_map); + for (mirror_index = 0; mirror_index < nmirrors; mirror_index++) { struct scrub_block *sblock; struct scrub_page *page; @@ -1265,26 +1360,38 @@ leave_nomem: spin_lock(&sctx->stat_lock); sctx->stat.malloc_errors++; spin_unlock(&sctx->stat_lock); - kfree(bbio); + scrub_put_recover(recover); return -ENOMEM; } scrub_page_get(page); sblock->pagev[page_index] = page; page->logical = logical; - page->physical = bbio->stripes[mirror_index].physical; + + scrub_stripe_index_and_offset(logical, raid_map, + mapped_length, + bbio->num_stripes, + mirror_index, + &stripe_index, + &stripe_offset); + page->physical = bbio->stripes[stripe_index].physical + + stripe_offset; + page->dev = bbio->stripes[stripe_index].dev; + BUG_ON(page_index >= original_sblock->page_count); page->physical_for_dev_replace = original_sblock->pagev[page_index]-> physical_for_dev_replace; /* for missing devices, dev->bdev is NULL */ - page->dev = bbio->stripes[mirror_index].dev; page->mirror_num = mirror_index + 1; sblock->page_count++; page->page = alloc_page(GFP_NOFS); if (!page->page) goto leave_nomem; + + scrub_get_recover(recover); + page->recover = recover; } - kfree(bbio); + scrub_put_recover(recover); length -= sublen; logical += sublen; page_index++; @@ -1293,6 +1400,51 @@ leave_nomem: return 0; } +struct scrub_bio_ret { + struct completion event; + int error; +}; + +static void scrub_bio_wait_endio(struct bio *bio, int error) +{ + struct scrub_bio_ret *ret = bio->bi_private; + + ret->error = error; + complete(&ret->event); +} + +static inline int scrub_is_page_on_raid56(struct scrub_page *page) +{ + return page->recover && page->recover->raid_map; +} + +static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info, + struct bio *bio, + struct scrub_page *page) +{ + struct scrub_bio_ret done; + int ret; + + init_completion(&done.event); + done.error = 0; + bio->bi_iter.bi_sector = page->logical >> 9; + bio->bi_private = &done; + bio->bi_end_io = scrub_bio_wait_endio; + + ret = raid56_parity_recover(fs_info->fs_root, bio, page->recover->bbio, + page->recover->raid_map, + page->recover->map_length, + page->mirror_num, 1); + if (ret) + return ret; + + wait_for_completion(&done.event); + if (done.error) + return -EIO; + + return 0; +} + /* * this function will check the on disk data for checksum errors, header * errors and read I/O errors. If any I/O errors happen, the exact pages @@ -1303,7 +1455,7 @@ leave_nomem: static void scrub_recheck_block(struct btrfs_fs_info *fs_info, struct scrub_block *sblock, int is_metadata, int have_csum, u8 *csum, u64 generation, - u16 csum_size) + u16 csum_size, int retry_failed_mirror) { int page_num; @@ -1329,11 +1481,17 @@ static void scrub_recheck_block(struct btrfs_fs_info *fs_info, continue; } bio->bi_bdev = page->dev->bdev; - bio->bi_iter.bi_sector = page->physical >> 9; bio_add_page(bio, page->page, PAGE_SIZE, 0); - if (btrfsic_submit_bio_wait(READ, bio)) - sblock->no_io_error_seen = 0; + if (!retry_failed_mirror && scrub_is_page_on_raid56(page)) { + if (scrub_submit_raid56_bio_wait(fs_info, bio, page)) + sblock->no_io_error_seen = 0; + } else { + bio->bi_iter.bi_sector = page->physical >> 9; + + if (btrfsic_submit_bio_wait(READ, bio)) + sblock->no_io_error_seen = 0; + } bio_put(bio); } -- cgit v1.2.1 From 5a6ac9eacb49143cbad3bbfda72263101cb1f3df Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Thu, 6 Nov 2014 17:20:58 +0800 Subject: Btrfs, raid56: support parity scrub on raid56 The implementation is: - Read and check all the data with checksum in the same stripe. All the data which has checksum is COW data, and we are sure that it is not changed though we don't lock the stripe. because the space of that data just can be reclaimed after the current transction is committed, and then the fs can use it to store the other data, but when doing scrub, we hold the current transaction, that is that data can not be recovered, it is safe that read and check it out of the stripe lock. - Lock the stripe - Read out all the data without checksum and parity The data without checksum and the parity may be changed if we don't lock the stripe, so we need read it in the stripe lock context. - Check the parity - Re-calculate the new parity and write back it if the old parity is not right - Unlock the stripe If we can not read out the data or the data we read is corrupted, we will try to repair it. If the repair fails. we will mark the horizontal sub-stripe(pages on the same horizontal) as corrupted sub-stripe, and we will skip the parity check and repair of that horizontal sub-stripe. And in order to skip the horizontal sub-stripe that has no data, we introduce a bitmap. If there is some data on the horizontal sub-stripe, we will the relative bit to 1, and when we check and repair the parity, we will skip those horizontal sub-stripes that the relative bits is 0. Signed-off-by: Miao Xie --- fs/btrfs/scrub.c | 609 +++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 595 insertions(+), 14 deletions(-) (limited to 'fs/btrfs/scrub.c') diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index ca4b9eb8b5da..7f95afcf9fd3 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -74,6 +74,7 @@ struct scrub_page { struct scrub_block *sblock; struct page *page; struct btrfs_device *dev; + struct list_head list; u64 flags; /* extent flags */ u64 generation; u64 logical; @@ -114,14 +115,52 @@ struct scrub_block { atomic_t outstanding_pages; atomic_t ref_count; /* free mem on transition to zero */ struct scrub_ctx *sctx; + struct scrub_parity *sparity; struct { unsigned int header_error:1; unsigned int checksum_error:1; unsigned int no_io_error_seen:1; unsigned int generation_error:1; /* also sets header_error */ + + /* The following is for the data used to check parity */ + /* It is for the data with checksum */ + unsigned int data_corrected:1; }; }; +/* Used for the chunks with parity stripe such RAID5/6 */ +struct scrub_parity { + struct scrub_ctx *sctx; + + struct btrfs_device *scrub_dev; + + u64 logic_start; + + u64 logic_end; + + int nsectors; + + int stripe_len; + + atomic_t ref_count; + + struct list_head spages; + + /* Work of parity check and repair */ + struct btrfs_work work; + + /* Mark the parity blocks which have data */ + unsigned long *dbitmap; + + /* + * Mark the parity blocks which have data, but errors happen when + * read data or check data + */ + unsigned long *ebitmap; + + unsigned long bitmap[0]; +}; + struct scrub_wr_ctx { struct scrub_bio *wr_curr_bio; struct btrfs_device *tgtdev; @@ -227,6 +266,8 @@ static void scrub_block_get(struct scrub_block *sblock); static void scrub_block_put(struct scrub_block *sblock); static void scrub_page_get(struct scrub_page *spage); static void scrub_page_put(struct scrub_page *spage); +static void scrub_parity_get(struct scrub_parity *sparity); +static void scrub_parity_put(struct scrub_parity *sparity); static int scrub_add_page_to_rd_bio(struct scrub_ctx *sctx, struct scrub_page *spage); static int scrub_pages(struct scrub_ctx *sctx, u64 logical, u64 len, @@ -943,6 +984,7 @@ static int scrub_handle_errored_block(struct scrub_block *sblock_to_check) */ spin_lock(&sctx->stat_lock); sctx->stat.unverified_errors++; + sblock_to_check->data_corrected = 1; spin_unlock(&sctx->stat_lock); if (sctx->is_dev_replace) @@ -1203,6 +1245,7 @@ nodatasum_case: corrected_error: spin_lock(&sctx->stat_lock); sctx->stat.corrected_errors++; + sblock_to_check->data_corrected = 1; spin_unlock(&sctx->stat_lock); printk_ratelimited_in_rcu(KERN_ERR "BTRFS: fixed up error at logical %llu on dev %s\n", @@ -1644,6 +1687,13 @@ static void scrub_write_block_to_dev_replace(struct scrub_block *sblock) { int page_num; + /* + * This block is used for the check of the parity on the source device, + * so the data needn't be written into the destination device. + */ + if (sblock->sparity) + return; + for (page_num = 0; page_num < sblock->page_count; page_num++) { int ret; @@ -2025,6 +2075,9 @@ static void scrub_block_put(struct scrub_block *sblock) if (atomic_dec_and_test(&sblock->ref_count)) { int i; + if (sblock->sparity) + scrub_parity_put(sblock->sparity); + for (i = 0; i < sblock->page_count; i++) scrub_page_put(sblock->pagev[i]); kfree(sblock); @@ -2282,9 +2335,51 @@ static void scrub_bio_end_io_worker(struct btrfs_work *work) scrub_pending_bio_dec(sctx); } +static inline void __scrub_mark_bitmap(struct scrub_parity *sparity, + unsigned long *bitmap, + u64 start, u64 len) +{ + int offset; + int nsectors; + int sectorsize = sparity->sctx->dev_root->sectorsize; + + if (len >= sparity->stripe_len) { + bitmap_set(bitmap, 0, sparity->nsectors); + return; + } + + start -= sparity->logic_start; + offset = (int)do_div(start, sparity->stripe_len); + offset /= sectorsize; + nsectors = (int)len / sectorsize; + + if (offset + nsectors <= sparity->nsectors) { + bitmap_set(bitmap, offset, nsectors); + return; + } + + bitmap_set(bitmap, offset, sparity->nsectors - offset); + bitmap_set(bitmap, 0, nsectors - (sparity->nsectors - offset)); +} + +static inline void scrub_parity_mark_sectors_error(struct scrub_parity *sparity, + u64 start, u64 len) +{ + __scrub_mark_bitmap(sparity, sparity->ebitmap, start, len); +} + +static inline void scrub_parity_mark_sectors_data(struct scrub_parity *sparity, + u64 start, u64 len) +{ + __scrub_mark_bitmap(sparity, sparity->dbitmap, start, len); +} + static void scrub_block_complete(struct scrub_block *sblock) { + int corrupted = 0; + if (!sblock->no_io_error_seen) { + corrupted = 1; scrub_handle_errored_block(sblock); } else { /* @@ -2292,9 +2387,19 @@ static void scrub_block_complete(struct scrub_block *sblock) * dev replace case, otherwise write here in dev replace * case. */ - if (!scrub_checksum(sblock) && sblock->sctx->is_dev_replace) + corrupted = scrub_checksum(sblock); + if (!corrupted && sblock->sctx->is_dev_replace) scrub_write_block_to_dev_replace(sblock); } + + if (sblock->sparity && corrupted && !sblock->data_corrected) { + u64 start = sblock->pagev[0]->logical; + u64 end = sblock->pagev[sblock->page_count - 1]->logical + + PAGE_SIZE; + + scrub_parity_mark_sectors_error(sblock->sparity, + start, end - start); + } } static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u64 len, @@ -2386,6 +2491,132 @@ behind_scrub_pages: return 0; } +static int scrub_pages_for_parity(struct scrub_parity *sparity, + u64 logical, u64 len, + u64 physical, struct btrfs_device *dev, + u64 flags, u64 gen, int mirror_num, u8 *csum) +{ + struct scrub_ctx *sctx = sparity->sctx; + struct scrub_block *sblock; + int index; + + sblock = kzalloc(sizeof(*sblock), GFP_NOFS); + if (!sblock) { + spin_lock(&sctx->stat_lock); + sctx->stat.malloc_errors++; + spin_unlock(&sctx->stat_lock); + return -ENOMEM; + } + + /* one ref inside this function, plus one for each page added to + * a bio later on */ + atomic_set(&sblock->ref_count, 1); + sblock->sctx = sctx; + sblock->no_io_error_seen = 1; + sblock->sparity = sparity; + scrub_parity_get(sparity); + + for (index = 0; len > 0; index++) { + struct scrub_page *spage; + u64 l = min_t(u64, len, PAGE_SIZE); + + spage = kzalloc(sizeof(*spage), GFP_NOFS); + if (!spage) { +leave_nomem: + spin_lock(&sctx->stat_lock); + sctx->stat.malloc_errors++; + spin_unlock(&sctx->stat_lock); + scrub_block_put(sblock); + return -ENOMEM; + } + BUG_ON(index >= SCRUB_MAX_PAGES_PER_BLOCK); + /* For scrub block */ + scrub_page_get(spage); + sblock->pagev[index] = spage; + /* For scrub parity */ + scrub_page_get(spage); + list_add_tail(&spage->list, &sparity->spages); + spage->sblock = sblock; + spage->dev = dev; + spage->flags = flags; + spage->generation = gen; + spage->logical = logical; + spage->physical = physical; + spage->mirror_num = mirror_num; + if (csum) { + spage->have_csum = 1; + memcpy(spage->csum, csum, sctx->csum_size); + } else { + spage->have_csum = 0; + } + sblock->page_count++; + spage->page = alloc_page(GFP_NOFS); + if (!spage->page) + goto leave_nomem; + len -= l; + logical += l; + physical += l; + } + + WARN_ON(sblock->page_count == 0); + for (index = 0; index < sblock->page_count; index++) { + struct scrub_page *spage = sblock->pagev[index]; + int ret; + + ret = scrub_add_page_to_rd_bio(sctx, spage); + if (ret) { + scrub_block_put(sblock); + return ret; + } + } + + /* last one frees, either here or in bio completion for last page */ + scrub_block_put(sblock); + return 0; +} + +static int scrub_extent_for_parity(struct scrub_parity *sparity, + u64 logical, u64 len, + u64 physical, struct btrfs_device *dev, + u64 flags, u64 gen, int mirror_num) +{ + struct scrub_ctx *sctx = sparity->sctx; + int ret; + u8 csum[BTRFS_CSUM_SIZE]; + u32 blocksize; + + if (flags & BTRFS_EXTENT_FLAG_DATA) { + blocksize = sctx->sectorsize; + } else if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { + blocksize = sctx->nodesize; + } else { + blocksize = sctx->sectorsize; + WARN_ON(1); + } + + while (len) { + u64 l = min_t(u64, len, blocksize); + int have_csum = 0; + + if (flags & BTRFS_EXTENT_FLAG_DATA) { + /* push csums to sbio */ + have_csum = scrub_find_csum(sctx, logical, l, csum); + if (have_csum == 0) + goto skip; + } + ret = scrub_pages_for_parity(sparity, logical, l, physical, dev, + flags, gen, mirror_num, + have_csum ? csum : NULL); +skip: + if (ret) + return ret; + len -= l; + logical += l; + physical += l; + } + return 0; +} + /* * Given a physical address, this will calculate it's * logical offset. if this is a parity stripe, it will return @@ -2394,7 +2625,8 @@ behind_scrub_pages: * return 0 if it is a data stripe, 1 means parity stripe. */ static int get_raid56_logic_offset(u64 physical, int num, - struct map_lookup *map, u64 *offset) + struct map_lookup *map, u64 *offset, + u64 *stripe_start) { int i; int j = 0; @@ -2405,6 +2637,9 @@ static int get_raid56_logic_offset(u64 physical, int num, last_offset = (physical - map->stripes[num].physical) * nr_data_stripes(map); + if (stripe_start) + *stripe_start = last_offset; + *offset = last_offset; for (i = 0; i < nr_data_stripes(map); i++) { *offset = last_offset + i * map->stripe_len; @@ -2427,13 +2662,330 @@ static int get_raid56_logic_offset(u64 physical, int num, return 1; } +static void scrub_free_parity(struct scrub_parity *sparity) +{ + struct scrub_ctx *sctx = sparity->sctx; + struct scrub_page *curr, *next; + int nbits; + + nbits = bitmap_weight(sparity->ebitmap, sparity->nsectors); + if (nbits) { + spin_lock(&sctx->stat_lock); + sctx->stat.read_errors += nbits; + sctx->stat.uncorrectable_errors += nbits; + spin_unlock(&sctx->stat_lock); + } + + list_for_each_entry_safe(curr, next, &sparity->spages, list) { + list_del_init(&curr->list); + scrub_page_put(curr); + } + + kfree(sparity); +} + +static void scrub_parity_bio_endio(struct bio *bio, int error) +{ + struct scrub_parity *sparity = (struct scrub_parity *)bio->bi_private; + struct scrub_ctx *sctx = sparity->sctx; + + if (error) + bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap, + sparity->nsectors); + + scrub_free_parity(sparity); + scrub_pending_bio_dec(sctx); + bio_put(bio); +} + +static void scrub_parity_check_and_repair(struct scrub_parity *sparity) +{ + struct scrub_ctx *sctx = sparity->sctx; + struct bio *bio; + struct btrfs_raid_bio *rbio; + struct scrub_page *spage; + struct btrfs_bio *bbio = NULL; + u64 *raid_map = NULL; + u64 length; + int ret; + + if (!bitmap_andnot(sparity->dbitmap, sparity->dbitmap, sparity->ebitmap, + sparity->nsectors)) + goto out; + + length = sparity->logic_end - sparity->logic_start + 1; + ret = btrfs_map_sblock(sctx->dev_root->fs_info, REQ_GET_READ_MIRRORS, + sparity->logic_start, + &length, &bbio, 0, &raid_map); + if (ret || !bbio || !raid_map) + goto bbio_out; + + bio = btrfs_io_bio_alloc(GFP_NOFS, 0); + if (!bio) + goto bbio_out; + + bio->bi_iter.bi_sector = sparity->logic_start >> 9; + bio->bi_private = sparity; + bio->bi_end_io = scrub_parity_bio_endio; + + rbio = raid56_parity_alloc_scrub_rbio(sctx->dev_root, bio, bbio, + raid_map, length, + sparity->scrub_dev, + sparity->dbitmap, + sparity->nsectors); + if (!rbio) + goto rbio_out; + + list_for_each_entry(spage, &sparity->spages, list) + raid56_parity_add_scrub_pages(rbio, spage->page, + spage->logical); + + scrub_pending_bio_inc(sctx); + raid56_parity_submit_scrub_rbio(rbio); + return; + +rbio_out: + bio_put(bio); +bbio_out: + kfree(bbio); + kfree(raid_map); + bitmap_or(sparity->ebitmap, sparity->ebitmap, sparity->dbitmap, + sparity->nsectors); + spin_lock(&sctx->stat_lock); + sctx->stat.malloc_errors++; + spin_unlock(&sctx->stat_lock); +out: + scrub_free_parity(sparity); +} + +static inline int scrub_calc_parity_bitmap_len(int nsectors) +{ + return DIV_ROUND_UP(nsectors, BITS_PER_LONG) * (BITS_PER_LONG / 8); +} + +static void scrub_parity_get(struct scrub_parity *sparity) +{ + atomic_inc(&sparity->ref_count); +} + +static void scrub_parity_put(struct scrub_parity *sparity) +{ + if (!atomic_dec_and_test(&sparity->ref_count)) + return; + + scrub_parity_check_and_repair(sparity); +} + +static noinline_for_stack int scrub_raid56_parity(struct scrub_ctx *sctx, + struct map_lookup *map, + struct btrfs_device *sdev, + struct btrfs_path *path, + u64 logic_start, + u64 logic_end) +{ + struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; + struct btrfs_root *root = fs_info->extent_root; + struct btrfs_root *csum_root = fs_info->csum_root; + struct btrfs_extent_item *extent; + u64 flags; + int ret; + int slot; + struct extent_buffer *l; + struct btrfs_key key; + u64 generation; + u64 extent_logical; + u64 extent_physical; + u64 extent_len; + struct btrfs_device *extent_dev; + struct scrub_parity *sparity; + int nsectors; + int bitmap_len; + int extent_mirror_num; + int stop_loop = 0; + + nsectors = map->stripe_len / root->sectorsize; + bitmap_len = scrub_calc_parity_bitmap_len(nsectors); + sparity = kzalloc(sizeof(struct scrub_parity) + 2 * bitmap_len, + GFP_NOFS); + if (!sparity) { + spin_lock(&sctx->stat_lock); + sctx->stat.malloc_errors++; + spin_unlock(&sctx->stat_lock); + return -ENOMEM; + } + + sparity->stripe_len = map->stripe_len; + sparity->nsectors = nsectors; + sparity->sctx = sctx; + sparity->scrub_dev = sdev; + sparity->logic_start = logic_start; + sparity->logic_end = logic_end; + atomic_set(&sparity->ref_count, 1); + INIT_LIST_HEAD(&sparity->spages); + sparity->dbitmap = sparity->bitmap; + sparity->ebitmap = (void *)sparity->bitmap + bitmap_len; + + ret = 0; + while (logic_start < logic_end) { + if (btrfs_fs_incompat(fs_info, SKINNY_METADATA)) + key.type = BTRFS_METADATA_ITEM_KEY; + else + key.type = BTRFS_EXTENT_ITEM_KEY; + key.objectid = logic_start; + key.offset = (u64)-1; + + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + goto out; + + if (ret > 0) { + ret = btrfs_previous_extent_item(root, path, 0); + if (ret < 0) + goto out; + if (ret > 0) { + btrfs_release_path(path); + ret = btrfs_search_slot(NULL, root, &key, + path, 0, 0); + if (ret < 0) + goto out; + } + } + + stop_loop = 0; + while (1) { + u64 bytes; + + l = path->nodes[0]; + slot = path->slots[0]; + if (slot >= btrfs_header_nritems(l)) { + ret = btrfs_next_leaf(root, path); + if (ret == 0) + continue; + if (ret < 0) + goto out; + + stop_loop = 1; + break; + } + btrfs_item_key_to_cpu(l, &key, slot); + + if (key.type == BTRFS_METADATA_ITEM_KEY) + bytes = root->nodesize; + else + bytes = key.offset; + + if (key.objectid + bytes <= logic_start) + goto next; + + if (key.type != BTRFS_EXTENT_ITEM_KEY && + key.type != BTRFS_METADATA_ITEM_KEY) + goto next; + + if (key.objectid > logic_end) { + stop_loop = 1; + break; + } + + while (key.objectid >= logic_start + map->stripe_len) + logic_start += map->stripe_len; + + extent = btrfs_item_ptr(l, slot, + struct btrfs_extent_item); + flags = btrfs_extent_flags(l, extent); + generation = btrfs_extent_generation(l, extent); + + if (key.objectid < logic_start && + (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) { + btrfs_err(fs_info, + "scrub: tree block %llu spanning stripes, ignored. logical=%llu", + key.objectid, logic_start); + goto next; + } +again: + extent_logical = key.objectid; + extent_len = bytes; + + if (extent_logical < logic_start) { + extent_len -= logic_start - extent_logical; + extent_logical = logic_start; + } + + if (extent_logical + extent_len > + logic_start + map->stripe_len) + extent_len = logic_start + map->stripe_len - + extent_logical; + + scrub_parity_mark_sectors_data(sparity, extent_logical, + extent_len); + + scrub_remap_extent(fs_info, extent_logical, + extent_len, &extent_physical, + &extent_dev, + &extent_mirror_num); + + ret = btrfs_lookup_csums_range(csum_root, + extent_logical, + extent_logical + extent_len - 1, + &sctx->csum_list, 1); + if (ret) + goto out; + + ret = scrub_extent_for_parity(sparity, extent_logical, + extent_len, + extent_physical, + extent_dev, flags, + generation, + extent_mirror_num); + if (ret) + goto out; + + scrub_free_csums(sctx); + if (extent_logical + extent_len < + key.objectid + bytes) { + logic_start += map->stripe_len; + + if (logic_start >= logic_end) { + stop_loop = 1; + break; + } + + if (logic_start < key.objectid + bytes) { + cond_resched(); + goto again; + } + } +next: + path->slots[0]++; + } + + btrfs_release_path(path); + + if (stop_loop) + break; + + logic_start += map->stripe_len; + } +out: + if (ret < 0) + scrub_parity_mark_sectors_error(sparity, logic_start, + logic_end - logic_start + 1); + scrub_parity_put(sparity); + scrub_submit(sctx); + mutex_lock(&sctx->wr_ctx.wr_lock); + scrub_wr_submit(sctx); + mutex_unlock(&sctx->wr_ctx.wr_lock); + + btrfs_release_path(path); + return ret < 0 ? ret : 0; +} + static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, struct map_lookup *map, struct btrfs_device *scrub_dev, int num, u64 base, u64 length, int is_dev_replace) { - struct btrfs_path *path; + struct btrfs_path *path, *ppath; struct btrfs_fs_info *fs_info = sctx->dev_root->fs_info; struct btrfs_root *root = fs_info->extent_root; struct btrfs_root *csum_root = fs_info->csum_root; @@ -2460,6 +3012,8 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, u64 extent_logical; u64 extent_physical; u64 extent_len; + u64 stripe_logical; + u64 stripe_end; struct btrfs_device *extent_dev; int extent_mirror_num; int stop_loop = 0; @@ -2485,7 +3039,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, mirror_num = num % map->num_stripes + 1; } else if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) { - get_raid56_logic_offset(physical, num, map, &offset); + get_raid56_logic_offset(physical, num, map, &offset, NULL); increment = map->stripe_len * nr_data_stripes(map); mirror_num = 1; } else { @@ -2497,6 +3051,12 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, if (!path) return -ENOMEM; + ppath = btrfs_alloc_path(); + if (!ppath) { + btrfs_free_path(ppath); + return -ENOMEM; + } + /* * work on commit root. The related disk blocks are static as * long as COW is applied. This means, it is save to rewrite @@ -2515,7 +3075,7 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) { get_raid56_logic_offset(physical_end, num, - map, &logic_end); + map, &logic_end, NULL); logic_end += base; } else { logic_end = logical + increment * nstripes; @@ -2562,10 +3122,18 @@ static noinline_for_stack int scrub_stripe(struct scrub_ctx *sctx, if (map->type & (BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6)) { ret = get_raid56_logic_offset(physical, num, - map, &logical); + map, &logical, &stripe_logical); logical += base; - if (ret) + if (ret) { + stripe_logical += base; + stripe_end = stripe_logical + increment - 1; + ret = scrub_raid56_parity(sctx, map, scrub_dev, + ppath, stripe_logical, + stripe_end); + if (ret) + goto out; goto skip; + } } /* * canceled? @@ -2716,13 +3284,25 @@ again: * loop until we find next data stripe * or we have finished all stripes. */ - do { - physical += map->stripe_len; - ret = get_raid56_logic_offset( - physical, num, - map, &logical); - logical += base; - } while (physical < physical_end && ret); +loop: + physical += map->stripe_len; + ret = get_raid56_logic_offset(physical, + num, map, &logical, + &stripe_logical); + logical += base; + + if (ret && physical < physical_end) { + stripe_logical += base; + stripe_end = stripe_logical + + increment - 1; + ret = scrub_raid56_parity(sctx, + map, scrub_dev, ppath, + stripe_logical, + stripe_end); + if (ret) + goto out; + goto loop; + } } else { physical += map->stripe_len; logical += increment; @@ -2763,6 +3343,7 @@ out: blk_finish_plug(&plug); btrfs_free_path(path); + btrfs_free_path(ppath); return ret < 0 ? ret : 0; } -- cgit v1.2.1 From 7603597690147a16b5cc77047d7570fa22a22673 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Fri, 14 Nov 2014 17:45:42 +0800 Subject: Btrfs, replace: write raid56 parity into the replace target device This function reused the code of parity scrub, and we just write the right parity or corrected parity into the target device before the parity scrub end. Signed-off-by: Miao Xie --- fs/btrfs/scrub.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/btrfs/scrub.c') diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 7f95afcf9fd3..0ae837fd676d 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -2714,7 +2714,7 @@ static void scrub_parity_check_and_repair(struct scrub_parity *sparity) goto out; length = sparity->logic_end - sparity->logic_start + 1; - ret = btrfs_map_sblock(sctx->dev_root->fs_info, REQ_GET_READ_MIRRORS, + ret = btrfs_map_sblock(sctx->dev_root->fs_info, WRITE, sparity->logic_start, &length, &bbio, 0, &raid_map); if (ret || !bbio || !raid_map) -- cgit v1.2.1 From 4245215d6a8dba1a51c50533b6667919687c0b89 Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Tue, 25 Nov 2014 16:39:28 +0800 Subject: Btrfs, raid56: fix use-after-free problem in the final device replace procedure on raid56 The commit c404e0dc (Btrfs: fix use-after-free in the finishing procedure of the device replace) fixed a use-after-free problem which happened when removing the source device at the end of device replace, but at that time, btrfs didn't support device replace on raid56, so we didn't fix the problem on the raid56 profile. Currently, we implemented device replace for raid56, so we need kick that problem out before we enable that function for raid56. The fix method is very simple, we just increase the bio per-cpu counter before we submit a raid56 io, and decrease the counter when the raid56 io ends. Signed-off-by: Miao Xie --- fs/btrfs/scrub.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/btrfs/scrub.c') diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 0ae837fd676d..27f2e16cd259 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -1477,7 +1477,7 @@ static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info, ret = raid56_parity_recover(fs_info->fs_root, bio, page->recover->bbio, page->recover->raid_map, page->recover->map_length, - page->mirror_num, 1); + page->mirror_num, 0); if (ret) return ret; -- cgit v1.2.1