extent_write_locked_range() is used when we're falling back to buffered IO from inside of compression. It allocates its own wbc and should associate it with the inode's i_wb to make sure the IO goes down from the correct cgroup. Also, export the needed symbols from fs-writeback.c. Signed-off-by: Chris Mason <clm@xxxxxx> Build-Breakage-Reported-by: kbuild test robot <lkp@xxxxxxxxx> --- v2: Module build fix. fs/btrfs/extent_io.c | 10 ++++++---- fs/fs-writeback.c | 3 +++ 2 files changed, 9 insertions(+), 4 deletions(-) --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4178,6 +4178,7 @@ int extent_write_locked_range(struct ino .no_wbc_acct = 1, }; + wbc_attach_fdatawrite_inode(&wbc_writepages, inode); while (start <= end) { page = find_get_page(mapping, start >> PAGE_SHIFT); if (clear_page_dirty_for_io(page)) @@ -4192,11 +4193,12 @@ int extent_write_locked_range(struct ino } ASSERT(ret <= 0); - if (ret < 0) { + if (ret == 0) + ret = flush_write_bio(&epd); + else end_write_bio(&epd, ret); - return ret; - } - ret = flush_write_bio(&epd); + + wbc_detach_inode(&wbc_writepages); return ret; } --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -270,6 +270,7 @@ void __inode_attach_wb(struct inode *ino if (unlikely(cmpxchg(&inode->i_wb, NULL, wb))) wb_put(wb); } +EXPORT_SYMBOL_GPL(__inode_attach_wb); /** * locked_inode_to_wb_and_lock_list - determine a locked inode's wb and lock it @@ -582,6 +583,7 @@ void wbc_attach_and_unlock_inode(struct if (unlikely(wb_dying(wbc->wb))) inode_switch_wbs(inode, wbc->wb_id); } +EXPORT_SYMBOL_GPL(wbc_attach_and_unlock_inode); /** * wbc_detach_inode - disassociate wbc from inode and perform foreign detection @@ -701,6 +703,7 @@ void wbc_detach_inode(struct writeback_c wb_put(wbc->wb); wbc->wb = NULL; } +EXPORT_SYMBOL_GPL(wbc_detach_inode); /** * wbc_account_io - account IO issued during writeback