From 78e62c02abb94e49ea739226a70325a6bf7a6603 Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Thu, 22 Nov 2018 10:17:49 +0200 Subject: [PATCH] btrfs: Remove extent_io_ops::readpage_io_failed_hook For data inodes this hook does nothing but to return -EAGAIN which is used to signal to the endio routines that this bio belongs to a data inode. If this is the case the actual retrying is handled by bio_readpage_error. Alternatively, if this bio belongs to the btree inode then btree_io_failed_hook just does some cleanup and doesn't retry anything. This patch simplifies the code flow by eliminating readpage_io_failed_hook and instead open-coding btree_io_failed_hook in end_bio_extent_readpage. Also eliminate some needless checks since IO is always performed on either data inode or btree inode, both of which are guaranteed to have their extent_io_tree::ops set. Signed-off-by: Nikolay Borisov Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/disk-io.c | 16 ---------- fs/btrfs/extent_io.c | 71 ++++++++++++++++++++++---------------------- fs/btrfs/extent_io.h | 1 - fs/btrfs/inode.c | 7 ----- 4 files changed, 35 insertions(+), 60 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 19b270368308..4bc270ef29b4 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -673,19 +673,6 @@ out: return ret; } -static int btree_io_failed_hook(struct page *page, int failed_mirror) -{ - struct extent_buffer *eb; - - eb = (struct extent_buffer *)page->private; - set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags); - eb->read_mirror = failed_mirror; - atomic_dec(&eb->io_pages); - if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) - btree_readahead_hook(eb, -EIO); - return -EIO; /* we fixed nothing */ -} - static void end_workqueue_bio(struct bio *bio) { struct btrfs_end_io_wq *end_io_wq = bio->bi_private; @@ -4560,7 +4547,4 @@ static const struct extent_io_ops btree_extent_io_ops = { /* mandatory callbacks */ .submit_bio_hook = btree_submit_bio_hook, .readpage_end_io_hook = btree_readpage_end_io_hook, - .readpage_io_failed_hook = btree_io_failed_hook, - - /* optional callbacks */ }; diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index aef3c9866ff0..582b4b1c41e0 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -2333,13 +2333,11 @@ struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio *failed_bio, } /* - * this is a generic handler for readpage errors (default - * readpage_io_failed_hook). if other copies exist, read those and write back - * good data to the failed position. does not investigate in remapping the - * failed extent elsewhere, hoping the device will be smart enough to do this as - * needed + * This is a generic handler for readpage errors. If other copies exist, read + * those and write back good data to the failed position. Does not investigate + * in remapping the failed extent elsewhere, hoping the device will be smart + * enough to do this as needed */ - static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset, struct page *page, u64 start, u64 end, int failed_mirror) @@ -2501,6 +2499,8 @@ static void end_bio_extent_readpage(struct bio *bio) struct page *page = bvec->bv_page; struct inode *inode = page->mapping->host; struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb); + bool data_inode = btrfs_ino(BTRFS_I(inode)) + != BTRFS_BTREE_INODE_OBJECTID; btrfs_debug(fs_info, "end_bio_extent_readpage: bi_sector=%llu, err=%d, mirror=%u", @@ -2530,7 +2530,7 @@ static void end_bio_extent_readpage(struct bio *bio) len = bvec->bv_len; mirror = io_bio->mirror_num; - if (likely(uptodate && tree->ops)) { + if (likely(uptodate)) { ret = tree->ops->readpage_end_io_hook(io_bio, offset, page, start, end, mirror); @@ -2546,38 +2546,37 @@ static void end_bio_extent_readpage(struct bio *bio) if (likely(uptodate)) goto readpage_ok; - if (tree->ops) { - ret = tree->ops->readpage_io_failed_hook(page, mirror); - 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_status; - offset += len; - continue; - } - } + if (data_inode) { /* - * metadata's readpage_io_failed_hook() always returns - * -EIO and fixes nothing. -EIO is also returned if - * data inode error could not be fixed. + * 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. */ - ASSERT(ret == -EIO); + ret = bio_readpage_error(bio, offset, page, start, end, + mirror); + if (ret == 0) { + uptodate = !bio->bi_status; + offset += len; + continue; + } + } else { + struct extent_buffer *eb; + + eb = (struct extent_buffer *)page->private; + set_bit(EXTENT_BUFFER_READ_ERR, &eb->bflags); + eb->read_mirror = mirror; + atomic_dec(&eb->io_pages); + if (test_and_clear_bit(EXTENT_BUFFER_READAHEAD, + &eb->bflags)) + btree_readahead_hook(eb, -EIO); + + ret = -EIO; } readpage_ok: if (likely(uptodate)) { diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index 17878eef9bcc..a1d3ea5a0d32 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -101,7 +101,6 @@ struct extent_io_ops { int (*readpage_end_io_hook)(struct btrfs_io_bio *io_bio, u64 phy_offset, struct page *page, u64 start, u64 end, int mirror); - int (*readpage_io_failed_hook)(struct page *page, int failed_mirror); }; struct extent_io_tree { diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 6bfd37e58924..c2c96acaf2fc 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -10409,12 +10409,6 @@ out: return ret; } -__attribute__((const)) -static int btrfs_readpage_io_failed_hook(struct page *page, int failed_mirror) -{ - return -EAGAIN; -} - void btrfs_set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end) { struct inode *inode = tree->private_data; @@ -10810,7 +10804,6 @@ static const struct extent_io_ops btrfs_extent_io_ops = { /* mandatory callbacks */ .submit_bio_hook = btrfs_submit_bio_hook, .readpage_end_io_hook = btrfs_readpage_end_io_hook, - .readpage_io_failed_hook = btrfs_readpage_io_failed_hook, }; /* -- 2.30.2