This BUG_ON() is really just a crappy way to workaround the _must_check attribute of submit_one_bio().
Now kill the BUG_ON() and allow flush_write_bio() to return error number. Also add _must_check attribute to flush_write_bio(), and modify all callers to handle the possible error returned. Signed-off-by: Qu Wenruo <[email protected]> --- fs/btrfs/extent_io.c | 77 +++++++++++++++++++++++++++++++++----------- 1 file changed, 58 insertions(+), 19 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 8a2335713a2d..a60f3ec22053 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -169,15 +169,15 @@ 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) +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 */ epd->bio = NULL; } + return ret; } int __init extent_io_init(void) @@ -3504,13 +3504,15 @@ lock_extent_buffer_for_io(struct extent_buffer *eb, struct btrfs_fs_info *fs_info, struct extent_page_data *epd) { - int i, num_pages; + int i, num_pages, failed_page_nr; int flush = 0; int ret = 0; if (!btrfs_try_tree_write_lock(eb)) { + ret = flush_write_bio(epd); + if (ret < 0) + return ret; flush = 1; - flush_write_bio(epd); btrfs_tree_lock(eb); } @@ -3519,7 +3521,9 @@ 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); + if (ret < 0) + return ret; flush = 1; } while (1) { @@ -3560,7 +3564,11 @@ lock_extent_buffer_for_io(struct extent_buffer *eb, if (!trylock_page(p)) { if (!flush) { - flush_write_bio(epd); + ret = flush_write_bio(epd); + if (ret < 0) { + failed_page_nr = i; + goto err_unlock; + } flush = 1; } lock_page(p); @@ -3568,6 +3576,15 @@ lock_extent_buffer_for_io(struct extent_buffer *eb, } return ret; + +err_unlock: + /* Unlock these already locked pages */ + for (i = 0; i < failed_page_nr; i++) { + struct page *p = eb->pages[i]; + + unlock_page(p); + } + return ret; } static void end_extent_buffer_writeback(struct extent_buffer *eb) @@ -3751,6 +3768,7 @@ 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; @@ -3818,6 +3836,11 @@ int btree_write_cache_pages(struct address_space *mapping, prev_eb = eb; ret = lock_extent_buffer_for_io(eb, fs_info, &epd); + if (ret < 0) { + free_extent_buffer(eb); + done = 1; + break; + } if (!ret) { free_extent_buffer(eb); continue; @@ -3850,8 +3873,10 @@ int btree_write_cache_pages(struct address_space *mapping, index = 0; goto retry; } - flush_write_bio(&epd); - return ret; + flush_ret = flush_write_bio(&epd); + if (ret) + return ret; + return flush_ret; } /** @@ -3947,7 +3972,9 @@ static int extent_write_cache_pages(struct address_space *mapping, * tmpfs file mapping */ if (!trylock_page(page)) { - flush_write_bio(epd); + ret = flush_write_bio(epd); + if (ret < 0) + break; lock_page(page); } @@ -3957,8 +3984,11 @@ static int extent_write_cache_pages(struct address_space *mapping, } if (wbc->sync_mode != WB_SYNC_NONE) { - if (PageWriteback(page)) - flush_write_bio(epd); + if (PageWriteback(page)) { + ret = flush_write_bio(epd); + if (ret < 0) + break; + } wait_on_page_writeback(page); } @@ -4019,6 +4049,7 @@ static int extent_write_cache_pages(struct address_space *mapping, 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, @@ -4028,14 +4059,17 @@ int extent_write_full_page(struct page *page, struct writeback_control *wbc) ret = __extent_writepage(page, wbc, &epd); - flush_write_bio(&epd); - return ret; + flush_ret = flush_write_bio(&epd); + if (ret) + return ret; + return flush_ret; } 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; @@ -4068,14 +4102,17 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end, start += PAGE_SIZE; } - flush_write_bio(&epd); - return ret; + flush_ret = flush_write_bio(&epd); + if (ret) + return ret; + return flush_ret; } 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, @@ -4084,8 +4121,10 @@ int extent_writepages(struct address_space *mapping, }; ret = extent_write_cache_pages(mapping, wbc, &epd); - flush_write_bio(&epd); - return ret; + flush_ret = flush_write_bio(&epd); + if (ret) + return ret; + return flush_ret; } int extent_readpages(struct address_space *mapping, struct list_head *pages, -- 2.20.1
