From f4340622e02261fae599e3da936ff4808b418173 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Wed, 20 Mar 2019 14:27:41 +0800 Subject: [PATCH] btrfs: extent_io: Move the BUG_ON() in flush_write_bio() one level up We have a BUG_ON() in flush_write_bio() to handle the return value of submit_one_bio(). Move the BUG_ON() one level up to all its callers. This patch will introduce temporary variable, @flush_ret to keep code change minimal in this patch. That variable will be cleaned up when enhancing the error handling later. Reviewed-by: Johannes Thumshirn Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/extent_io.c | 55 +++++++++++++++++++++++++++++++++----------- 1 file changed, 41 insertions(+), 14 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index d0b8ed2c2631..43091b29b8d7 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -170,15 +170,28 @@ static int __must_check submit_one_bio(struct bio *bio, int mirror_num, return blk_status_to_errno(ret); } -static void flush_write_bio(struct extent_page_data *epd) +/* + * Submit bio from extent page data via submit_one_bio + * + * Return 0 if everything is OK. + * Return <0 for error. + */ +static int __must_check flush_write_bio(struct extent_page_data *epd) { - if (epd->bio) { - int ret; + int ret = 0; + if (epd->bio) { ret = submit_one_bio(epd->bio, 0, 0); - BUG_ON(ret < 0); /* -ENOMEM */ + /* + * Clean up of epd->bio is handled by its endio function. + * And endio is either triggered by successful bio execution + * or the error handler of submit bio hook. + * So at this point, no matter what happened, we don't need + * to clean up epd->bio. + */ epd->bio = NULL; } + return ret; } int __init extent_io_init(void) @@ -3476,7 +3489,8 @@ lock_extent_buffer_for_io(struct extent_buffer *eb, if (!btrfs_try_tree_write_lock(eb)) { flush = 1; - flush_write_bio(epd); + ret = flush_write_bio(epd); + BUG_ON(ret < 0); btrfs_tree_lock(eb); } @@ -3485,7 +3499,8 @@ lock_extent_buffer_for_io(struct extent_buffer *eb, if (!epd->sync_io) return 0; if (!flush) { - flush_write_bio(epd); + ret = flush_write_bio(epd); + BUG_ON(ret < 0); flush = 1; } while (1) { @@ -3526,7 +3541,8 @@ lock_extent_buffer_for_io(struct extent_buffer *eb, if (!trylock_page(p)) { if (!flush) { - flush_write_bio(epd); + ret = flush_write_bio(epd); + BUG_ON(ret < 0); flush = 1; } lock_page(p); @@ -3718,6 +3734,7 @@ int btree_write_cache_pages(struct address_space *mapping, .sync_io = wbc->sync_mode == WB_SYNC_ALL, }; int ret = 0; + int flush_ret; int done = 0; int nr_to_write_done = 0; struct pagevec pvec; @@ -3817,7 +3834,8 @@ retry: index = 0; goto retry; } - flush_write_bio(&epd); + flush_ret = flush_write_bio(&epd); + BUG_ON(flush_ret < 0); return ret; } @@ -3914,7 +3932,8 @@ retry: * tmpfs file mapping */ if (!trylock_page(page)) { - flush_write_bio(epd); + ret = flush_write_bio(epd); + BUG_ON(ret < 0); lock_page(page); } @@ -3924,8 +3943,10 @@ retry: } if (wbc->sync_mode != WB_SYNC_NONE) { - if (PageWriteback(page)) - flush_write_bio(epd); + if (PageWriteback(page)) { + ret = flush_write_bio(epd); + BUG_ON(ret < 0); + } wait_on_page_writeback(page); } @@ -3986,6 +4007,7 @@ retry: int extent_write_full_page(struct page *page, struct writeback_control *wbc) { int ret; + int flush_ret; struct extent_page_data epd = { .bio = NULL, .tree = &BTRFS_I(page->mapping->host)->io_tree, @@ -3995,7 +4017,8 @@ int extent_write_full_page(struct page *page, struct writeback_control *wbc) ret = __extent_writepage(page, wbc, &epd); - flush_write_bio(&epd); + flush_ret = flush_write_bio(&epd); + BUG_ON(flush_ret < 0); return ret; } @@ -4003,6 +4026,7 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end, int mode) { int ret = 0; + int flush_ret; struct address_space *mapping = inode->i_mapping; struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; struct page *page; @@ -4035,7 +4059,8 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end, start += PAGE_SIZE; } - flush_write_bio(&epd); + flush_ret = flush_write_bio(&epd); + BUG_ON(flush_ret < 0); return ret; } @@ -4043,6 +4068,7 @@ int extent_writepages(struct address_space *mapping, struct writeback_control *wbc) { int ret = 0; + int flush_ret; struct extent_page_data epd = { .bio = NULL, .tree = &BTRFS_I(mapping->host)->io_tree, @@ -4051,7 +4077,8 @@ int extent_writepages(struct address_space *mapping, }; ret = extent_write_cache_pages(mapping, wbc, &epd); - flush_write_bio(&epd); + flush_ret = flush_write_bio(&epd); + BUG_ON(flush_ret < 0); return ret; } -- 2.34.1