From 9d0d1c8b1c9d80b17cfa86ecd50c8933a742585c Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Fri, 24 Mar 2017 15:04:50 -0700 Subject: [PATCH] Btrfs: bring back repair during read Commit 20a7db8ab3f2 ("btrfs: add dummy callback for readpage_io_failed and drop checks") made a cleanup around readpage_io_failed_hook, and it was supposed to keep the original sematics, but it also unexpectedly disabled repair during read for dup, raid1 and raid10. This fixes the problem by letting data's inode call the generic readpage_io_failed callback by returning -EAGAIN from its readpage_io_failed_hook in order to notify end_bio_extent_readpage to do the rest. We don't call it directly because the generic one takes an offset from end_bio_extent_readpage() to calculate the index in the checksum array and inode's readpage_io_failed_hook doesn't offer that offset. Cc: David Sterba Signed-off-by: Liu Bo Reviewed-by: David Sterba [ keep the const function attribute ] Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 46 +++++++++++++++++++++++++++----------------- fs/btrfs/inode.c | 6 +++--- 2 files changed, 31 insertions(+), 21 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 8df797432740..27fdb250b446 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2584,26 +2584,36 @@ static void end_bio_extent_readpage(struct bio *bio) if (tree->ops) { ret = tree->ops->readpage_io_failed_hook(page, mirror); - if (!ret && !bio->bi_error) - uptodate = 1; - } else { + if (ret == -EAGAIN) { + /* + * Data inode's readpage_io_failed_hook() always + * returns -EAGAIN. + * + * The generic bio_readpage_error handles errors + * the following way: If possible, new read + * requests are created and submitted and will + * end up in end_bio_extent_readpage as well (if + * we're lucky, not in the !uptodate case). In + * that case it returns 0 and we just go on with + * the next page in our bio. If it can't handle + * the error it will return -EIO and we remain + * responsible for that page. + */ + ret = bio_readpage_error(bio, offset, page, + start, end, mirror); + if (ret == 0) { + uptodate = !bio->bi_error; + offset += len; + continue; + } + } + /* - * The generic bio_readpage_error handles errors the - * following way: If possible, new read requests are - * created and submitted and will end up in - * end_bio_extent_readpage as well (if we're lucky, not - * in the !uptodate case). In that case it returns 0 and - * we just go on with the next page in our bio. If it - * can't handle the error it will return -EIO and we - * remain responsible for that page. + * metadata's readpage_io_failed_hook() always returns + * -EIO and fixes nothing. -EIO is also returned if + * data inode error could not be fixed. */ - ret = bio_readpage_error(bio, offset, page, start, end, - mirror); - if (ret == 0) { - uptodate = !bio->bi_error; - offset += len; - continue; - } + ASSERT(ret == -EIO); } readpage_ok: if (likely(uptodate)) { diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index e57191072aa3..876f1d36030c 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -10523,9 +10523,9 @@ out_inode: } __attribute__((const)) -static int dummy_readpage_io_failed_hook(struct page *page, int failed_mirror) +static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror) { - return 0; + return -EAGAIN; } static const struct inode_operations btrfs_dir_inode_operations = { @@ -10570,7 +10570,7 @@ static const struct extent_io_ops btrfs_extent_io_ops = { .submit_bio_hook = btrfs_submit_bio_hook, .readpage_end_io_hook = btrfs_readpage_end_io_hook, .merge_bio_hook = btrfs_merge_bio_hook, - .readpage_io_failed_hook = dummy_readpage_io_failed_hook, + .readpage_io_failed_hook = btrfs_readpage_io_failed_hook, /* optional callbacks */ .fill_delalloc = run_delalloc_range, -- 2.20.1