diff options
| -rw-r--r-- | fs/btrfs/scrub.c | 152 |
1 files changed, 112 insertions, 40 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index 91aeac36ebc9..c83ac6b80c2f 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -423,11 +423,6 @@ static int scrub_sectors(struct scrub_ctx *sctx, u64 logical, u32 len, static void scrub_bio_end_io(struct bio *bio); static void scrub_bio_end_io_worker(struct work_struct *work); static void scrub_block_complete(struct scrub_block *sblock); -static void scrub_find_good_copy(struct btrfs_fs_info *fs_info, - u64 extent_logical, u32 extent_len, - u64 *extent_physical, - struct btrfs_device **extent_dev, - int *extent_mirror_num); static int scrub_add_sector_to_wr_bio(struct scrub_ctx *sctx, struct scrub_sector *sector); static void scrub_wr_submit(struct scrub_ctx *sctx); @@ -2710,6 +2705,110 @@ static int scrub_find_csum(struct scrub_ctx *sctx, u64 logical, u8 *csum) return 1; } +static bool should_use_device(struct btrfs_fs_info *fs_info, + struct btrfs_device *dev, + bool follow_replace_read_mode) +{ + struct btrfs_device *replace_srcdev = fs_info->dev_replace.srcdev; + struct btrfs_device *replace_tgtdev = fs_info->dev_replace.tgtdev; + + if (!dev->bdev) + return false; + + /* + * We're doing scrub/replace, if it's pure scrub, no tgtdev should be + * here. If it's replace, we're going to write data to tgtdev, thus + * the current data of the tgtdev is all garbage, thus we can not use + * it at all. + */ + if (dev == replace_tgtdev) + return false; + + /* No need to follow replace read mode, any existing device is fine. */ + if (!follow_replace_read_mode) + return true; + + /* Need to follow the mode. */ + if (fs_info->dev_replace.cont_reading_from_srcdev_mode == + BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID) + return dev != replace_srcdev; + return true; +} +static int scrub_find_good_copy(struct btrfs_fs_info *fs_info, + u64 extent_logical, u32 extent_len, + u64 *extent_physical, + struct btrfs_device **extent_dev, + int *extent_mirror_num) +{ + u64 mapped_length; + struct btrfs_io_context *bioc = NULL; + int ret; + int i; + + mapped_length = extent_len; + ret = btrfs_map_block(fs_info, BTRFS_MAP_GET_READ_MIRRORS, + extent_logical, &mapped_length, &bioc, 0); + if (ret || !bioc || mapped_length < extent_len) { + btrfs_put_bioc(bioc); + btrfs_err_rl(fs_info, "btrfs_map_block() failed for logical %llu: %d", + extent_logical, ret); + return -EIO; + } + + /* + * First loop to exclude all missing devices and the source device if + * needed. And we don't want to use target device as mirror either, as + * we're doing the replace, the target device range contains nothing. + */ + for (i = 0; i < bioc->num_stripes - bioc->replace_nr_stripes; i++) { + struct btrfs_io_stripe *stripe = &bioc->stripes[i]; + + if (!should_use_device(fs_info, stripe->dev, true)) + continue; + goto found; + } + /* + * We didn't find any alternative mirrors, we have to break our replace + * read mode, or we can not read at all. + */ + for (i = 0; i < bioc->num_stripes - bioc->replace_nr_stripes; i++) { + struct btrfs_io_stripe *stripe = &bioc->stripes[i]; + + if (!should_use_device(fs_info, stripe->dev, false)) + continue; + goto found; + } + + btrfs_err_rl(fs_info, "failed to find any live mirror for logical %llu", + extent_logical); + return -EIO; + +found: + *extent_physical = bioc->stripes[i].physical; + *extent_mirror_num = i + 1; + *extent_dev = bioc->stripes[i].dev; + btrfs_put_bioc(bioc); + return 0; +} + +static bool scrub_need_different_mirror(struct scrub_ctx *sctx, + struct map_lookup *map, + struct btrfs_device *dev) +{ + /* + * For RAID56, all the extra mirrors are rebuilt from other P/Q, + * cannot utilize other mirrors directly. + */ + if (map->type & BTRFS_BLOCK_GROUP_RAID56_MASK) + return false; + + if (!dev->bdev) + return true; + + return sctx->fs_info->dev_replace.cont_reading_from_srcdev_mode == + BTRFS_DEV_REPLACE_ITEM_CONT_READING_FROM_SRCDEV_MODE_AVOID; +} + /* scrub extent tries to collect up to 64 kB for each bio */ static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map, u64 logical, u32 len, @@ -2747,17 +2846,15 @@ static int scrub_extent(struct scrub_ctx *sctx, struct map_lookup *map, } /* - * For dev-replace case, we can have @dev being a missing device. - * Regular scrub will avoid its execution on missing device at all, - * as that would trigger tons of read error. - * - * Reading from missing device will cause read error counts to - * increase unnecessarily. - * So here we change the read source to a good mirror. + * For dev-replace case, we can have @dev being a missing device, or + * we want to avoid reading from the source device if possible. */ - if (sctx->is_dev_replace && !dev->bdev) - scrub_find_good_copy(sctx->fs_info, logical, len, &src_physical, - &src_dev, &src_mirror); + if (sctx->is_dev_replace && scrub_need_different_mirror(sctx, map, dev)) { + ret = scrub_find_good_copy(sctx->fs_info, logical, len, + &src_physical, &src_dev, &src_mirror); + if (ret < 0) + return ret; + } while (len) { u32 l = min(len, blocksize); int have_csum = 0; @@ -4544,28 +4641,3 @@ int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid, return dev ? (sctx ? 0 : -ENOTCONN) : -ENODEV; } - -static void scrub_find_good_copy(struct btrfs_fs_info *fs_info, - u64 extent_logical, u32 extent_len, - u64 *extent_physical, - struct btrfs_device **extent_dev, - int *extent_mirror_num) -{ - u64 mapped_length; - struct btrfs_io_context *bioc = NULL; - int ret; - - mapped_length = extent_len; - ret = btrfs_map_block(fs_info, BTRFS_MAP_READ, extent_logical, - &mapped_length, &bioc, 0); - if (ret || !bioc || mapped_length < extent_len || - !bioc->stripes[0].dev->bdev) { - btrfs_put_bioc(bioc); - return; - } - - *extent_physical = bioc->stripes[0].physical; - *extent_mirror_num = bioc->mirror_num; - *extent_dev = bioc->stripes[0].dev; - btrfs_put_bioc(bioc); -} |