f2fs: fix not to write data pages on the page reclaiming path (8618b881) · Commits · 戴 / test

Even if f2fs_write_data_page is called by the page reclaiming path, we should not write the page to provide enough free segments for the worst case scenario. Otherwise, f2fs can face with no free segment while gc is conducted, resulting in: ------------[ cut here ]------------ kernel BUG at /home/zeus/f2fs_test/src/fs/f2fs/segment.c:565! RIP: 0010:[<ffffffffa02c3b11>] [<ffffffffa02c3b11>] new_curseg+0x331/0x340 [f2fs] Call Trace: allocate_segment_by_default+0x204/0x280 [f2fs] allocate_data_block+0x108/0x210 [f2fs] write_data_page+0x8a/0xc0 [f2fs] do_write_data_page+0xe1/0x2a0 [f2fs] move_data_page+0x8a/0xf0 [f2fs] f2fs_gc+0x446/0x970 [f2fs] f2fs_balance_fs+0xb6/0xd0 [f2fs] f2fs_write_begin+0x50/0x350 [f2fs] ? unlock_page+0x27/0x30 ? unlock_page+0x27/0x30 generic_file_buffered_write+0x10a/0x280 ? file_update_time+0xa3/0xf0 __generic_file_aio_write+0x1c8/0x3d0 ? generic_file_aio_write+0x52/0xb0 ? generic_file_aio_write+0x52/0xb0 generic_file_aio_write+0x65/0xb0 do_sync_write+0x5a/0x90 vfs_write+0xc5/0x1f0 SyS_write+0x55/0xa0 system_call_fastpath+0x16/0x1b Signed-off-by:

Jaegeuk Kim <jaegeuk.kim@samsung.com>

fs/f2fs/data.c

+15 −23

Original line number	Diff line number	Diff line
		@@ -805,38 +805,30 @@ static int f2fs_write_data_page(struct page *page,

		zero_user_segment(page, offset, PAGE_CACHE_SIZE);
		write:
		if (unlikely(sbi->por_doing)) {
		err = AOP_WRITEPAGE_ACTIVATE;
		if (unlikely(sbi->por_doing))
		goto redirty_out;
		}

		/* Dentry blocks are controlled by checkpoint */
		if (S_ISDIR(inode->i_mode)) {
		inode_dec_dirty_dents(inode);
		err = do_write_data_page(page, &fio);
		} else {
		f2fs_lock_op(sbi);

		if (f2fs_has_inline_data(inode) \|\| f2fs_may_inline(inode)) {
		err = f2fs_write_inline_data(inode, page, offset);
		f2fs_unlock_op(sbi);
		goto out;
		} else {
		err = do_write_data_page(page, &fio);
		goto done;
		}

		f2fs_unlock_op(sbi);
		if (!wbc->for_reclaim)
		need_balance_fs = true;
		}
		if (err == -ENOENT)
		goto out;
		else if (err)
		else if (has_not_enough_free_secs(sbi, 0))
		goto redirty_out;

		if (wbc->for_reclaim) {
		f2fs_submit_merged_bio(sbi, DATA, WRITE);
		need_balance_fs = false;
		}
		f2fs_lock_op(sbi);
		if (f2fs_has_inline_data(inode) \|\| f2fs_may_inline(inode))
		err = f2fs_write_inline_data(inode, page, offset);
		else
		err = do_write_data_page(page, &fio);
		f2fs_unlock_op(sbi);
		done:
		if (err && err != -ENOENT)
		goto redirty_out;

		clear_cold_data(page);
		out:
		@@ -848,7 +840,7 @@ out:
		redirty_out:
		wbc->pages_skipped++;
		set_page_dirty(page);
		return err;
		return AOP_WRITEPAGE_ACTIVATE;
		}

		#define MAX_DESIRED_PAGES_WP 4096

Admin message