Re: [PATCH v2] f2fs: fix to read source block before invalidating it

From: Jaegeuk Kim
Date: Wed Jul 17 2019 - 23:12:30 EST


f2fs_allocate_data_block() invalidates old block address and enable new block
address. Then, if we try to read old block by f2fs_submit_page_bio(), it will
give WARN due to reading invalid blocks.

Let's make the order sanely back.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
v2:
I was fixing the comments. :)

fs/f2fs/gc.c | 70 +++++++++++++++++++++++++---------------------------
1 file changed, 34 insertions(+), 36 deletions(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 6691f526fa40..8974672db78f 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -796,6 +796,29 @@ static int move_data_block(struct inode *inode, block_t bidx,
if (lfs_mode)
down_write(&fio.sbi->io_order_lock);

+ mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
+ fio.old_blkaddr, false);
+ if (!mpage)
+ goto up_out;
+
+ fio.encrypted_page = mpage;
+
+ /* read source block in mpage */
+ if (!PageUptodate(mpage)) {
+ err = f2fs_submit_page_bio(&fio);
+ if (err) {
+ f2fs_put_page(mpage, 1);
+ goto up_out;
+ }
+ lock_page(mpage);
+ if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
+ !PageUptodate(mpage))) {
+ err = -EIO;
+ f2fs_put_page(mpage, 1);
+ goto up_out;
+ }
+ }
+
f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
&sum, CURSEG_COLD_DATA, NULL, false);

@@ -803,44 +826,18 @@ static int move_data_block(struct inode *inode, block_t bidx,
newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
if (!fio.encrypted_page) {
err = -ENOMEM;
- goto recover_block;
- }
-
- mpage = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
- fio.old_blkaddr, FGP_LOCK, GFP_NOFS);
- if (mpage) {
- bool updated = false;
-
- if (PageUptodate(mpage)) {
- memcpy(page_address(fio.encrypted_page),
- page_address(mpage), PAGE_SIZE);
- updated = true;
- }
f2fs_put_page(mpage, 1);
- invalidate_mapping_pages(META_MAPPING(fio.sbi),
- fio.old_blkaddr, fio.old_blkaddr);
- if (updated)
- goto write_page;
- }
-
- err = f2fs_submit_page_bio(&fio);
- if (err)
- goto put_page_out;
-
- /* write page */
- lock_page(fio.encrypted_page);
-
- if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) {
- err = -EIO;
- goto put_page_out;
- }
- if (unlikely(!PageUptodate(fio.encrypted_page))) {
- err = -EIO;
- goto put_page_out;
+ goto recover_block;
}

-write_page:
+ /* write target block */
f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
+ memcpy(page_address(fio.encrypted_page),
+ page_address(mpage), PAGE_SIZE);
+ f2fs_put_page(mpage, 1);
+ invalidate_mapping_pages(META_MAPPING(fio.sbi),
+ fio.old_blkaddr, fio.old_blkaddr);
+
set_page_dirty(fio.encrypted_page);
if (clear_page_dirty_for_io(fio.encrypted_page))
dec_page_count(fio.sbi, F2FS_DIRTY_META);
@@ -871,11 +868,12 @@ static int move_data_block(struct inode *inode, block_t bidx,
put_page_out:
f2fs_put_page(fio.encrypted_page, 1);
recover_block:
- if (lfs_mode)
- up_write(&fio.sbi->io_order_lock);
if (err)
f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
true, true);
+up_out:
+ if (lfs_mode)
+ up_write(&fio.sbi->io_order_lock);
put_out:
f2fs_put_dnode(&dn);
out:
--
2.19.0.605.g01d371f741-goog