From: Christoph Hellwig hch@lst.de
[ Upstream commit c144c63fd33a1fc0e43e0b851a35b09c9460d94d ]
When there is more than a single level of redundancy there can also be multiple bad mirrors, and the current read repair code only repairs the last bad one.
Restructure btrfs_repair_one_sector so that it records the originally failed mirror and the number of copies, and then repair all known bad copies until we reach the originally failed copy in clean_io_failure. Note that this also means the read repair reads will always start from the next bad mirror and not mirror 0.
This fixes btrfs/265 in xfstests.
Reviewed-by: Nikolay Borisov nborisov@suse.com Signed-off-by: Christoph Hellwig hch@lst.de Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/extent_io.c | 126 +++++++++++++++++++++---------------------- fs/btrfs/extent_io.h | 1 + 2 files changed, 61 insertions(+), 66 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index f03ab5dbda7a..48fff4801eb7 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2418,6 +2418,20 @@ int btrfs_repair_eb_io_failure(const struct extent_buffer *eb, int mirror_num) return ret; }
+static int next_mirror(const struct io_failure_record *failrec, int cur_mirror) +{ + if (cur_mirror == failrec->num_copies) + return cur_mirror + 1 - failrec->num_copies; + return cur_mirror + 1; +} + +static int prev_mirror(const struct io_failure_record *failrec, int cur_mirror) +{ + if (cur_mirror == 1) + return failrec->num_copies; + return cur_mirror - 1; +} + /* * each time an IO finishes, we do a fast check in the IO failure tree * to see if we need to process or clean up an io_failure_record @@ -2430,7 +2444,7 @@ int clean_io_failure(struct btrfs_fs_info *fs_info, u64 private; struct io_failure_record *failrec; struct extent_state *state; - int num_copies; + int mirror; int ret;
private = 0; @@ -2454,20 +2468,19 @@ int clean_io_failure(struct btrfs_fs_info *fs_info, EXTENT_LOCKED); spin_unlock(&io_tree->lock);
- if (state && state->start <= failrec->start && - state->end >= failrec->start + failrec->len - 1) { - num_copies = btrfs_num_copies(fs_info, failrec->logical, - failrec->len); - if (num_copies > 1) { - repair_io_failure(fs_info, ino, start, failrec->len, - failrec->logical, page, pg_offset, - failrec->failed_mirror); - } - } + if (!state || state->start > failrec->start || + state->end < failrec->start + failrec->len - 1) + goto out; + + mirror = failrec->this_mirror; + do { + mirror = prev_mirror(failrec, mirror); + repair_io_failure(fs_info, ino, start, failrec->len, + failrec->logical, page, pg_offset, mirror); + } while (mirror != failrec->failed_mirror);
out: free_io_failure(failure_tree, io_tree, failrec); - return 0; }
@@ -2506,7 +2519,8 @@ void btrfs_free_io_failure_record(struct btrfs_inode *inode, u64 start, u64 end) }
static struct io_failure_record *btrfs_get_io_failure_record(struct inode *inode, - u64 start) + u64 start, + int failed_mirror) { struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); struct io_failure_record *failrec; @@ -2528,7 +2542,8 @@ static struct io_failure_record *btrfs_get_io_failure_record(struct inode *inode * (e.g. with a list for failed_mirror) to make * clean_io_failure() clean all those errors at once. */ - + ASSERT(failrec->this_mirror == failed_mirror); + ASSERT(failrec->len == fs_info->sectorsize); return failrec; }
@@ -2538,7 +2553,8 @@ static struct io_failure_record *btrfs_get_io_failure_record(struct inode *inode
failrec->start = start; failrec->len = sectorsize; - failrec->this_mirror = 0; + failrec->failed_mirror = failed_mirror; + failrec->this_mirror = failed_mirror; failrec->compress_type = BTRFS_COMPRESS_NONE;
read_lock(&em_tree->lock); @@ -2573,6 +2589,20 @@ static struct io_failure_record *btrfs_get_io_failure_record(struct inode *inode failrec->logical = logical; free_extent_map(em);
+ failrec->num_copies = btrfs_num_copies(fs_info, logical, sectorsize); + if (failrec->num_copies == 1) { + /* + * We only have a single copy of the data, so don't bother with + * all the retry and error correction code that follows. No + * matter what the error is, it is very likely to persist. + */ + btrfs_debug(fs_info, + "cannot repair logical %llu num_copies %d", + failrec->logical, failrec->num_copies); + kfree(failrec); + return ERR_PTR(-EIO); + } + /* Set the bits in the private failure tree */ ret = set_extent_bits(failure_tree, start, start + sectorsize - 1, EXTENT_LOCKED | EXTENT_DIRTY); @@ -2589,54 +2619,6 @@ static struct io_failure_record *btrfs_get_io_failure_record(struct inode *inode return failrec; }
-static bool btrfs_check_repairable(struct inode *inode, - struct io_failure_record *failrec, - int failed_mirror) -{ - struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); - int num_copies; - - num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len); - if (num_copies == 1) { - /* - * we only have a single copy of the data, so don't bother with - * all the retry and error correction code that follows. no - * matter what the error is, it is very likely to persist. - */ - btrfs_debug(fs_info, - "Check Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d", - num_copies, failrec->this_mirror, failed_mirror); - return false; - } - - /* The failure record should only contain one sector */ - ASSERT(failrec->len == fs_info->sectorsize); - - /* - * There are two premises: - * a) deliver good data to the caller - * b) correct the bad sectors on disk - * - * Since we're only doing repair for one sector, we only need to get - * a good copy of the failed sector and if we succeed, we have setup - * everything for repair_io_failure to do the rest for us. - */ - ASSERT(failed_mirror); - failrec->failed_mirror = failed_mirror; - failrec->this_mirror++; - if (failrec->this_mirror == failed_mirror) - failrec->this_mirror++; - - if (failrec->this_mirror > num_copies) { - btrfs_debug(fs_info, - "Check Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d", - num_copies, failrec->this_mirror, failed_mirror); - return false; - } - - return true; -} - int btrfs_repair_one_sector(struct inode *inode, struct bio *failed_bio, u32 bio_offset, struct page *page, unsigned int pgoff, @@ -2657,12 +2639,24 @@ int btrfs_repair_one_sector(struct inode *inode,
BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
- failrec = btrfs_get_io_failure_record(inode, start); + failrec = btrfs_get_io_failure_record(inode, start, failed_mirror); if (IS_ERR(failrec)) return PTR_ERR(failrec);
- - if (!btrfs_check_repairable(inode, failrec, failed_mirror)) { + /* + * There are two premises: + * a) deliver good data to the caller + * b) correct the bad sectors on disk + * + * Since we're only doing repair for one sector, we only need to get + * a good copy of the failed sector and if we succeed, we have setup + * everything for repair_io_failure to do the rest for us. + */ + failrec->this_mirror = next_mirror(failrec, failrec->this_mirror); + if (failrec->this_mirror == failrec->failed_mirror) { + btrfs_debug(fs_info, + "failed to repair num_copies %d this_mirror %d failed_mirror %d", + failrec->num_copies, failrec->this_mirror, failrec->failed_mirror); free_io_failure(failure_tree, tree, failrec); return -EIO; } diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 23d4103c8831..acee497bab7b 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -269,6 +269,7 @@ struct io_failure_record { enum btrfs_compression_type compress_type; int this_mirror; int failed_mirror; + int num_copies; };
int btrfs_repair_one_sector(struct inode *inode,