Commit a4d7f2b3 authored by Chao Yu's avatar Chao Yu Committed by Jaegeuk Kim
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f2fs: fix to wait page writeback before setting gcing flag 



Soft IRQ				Thread
- f2fs_write_end_io
					- f2fs_defragment_range
					 - set_page_private_gcing
 - type = WB_DATA_TYPE(page, false);
 : assign type w/ F2FS_WB_CP_DATA
 due to page_private_gcing() is true
  - dec_page_count() w/ wrong type
  - end_page_writeback()

Value of F2FS_WB_CP_DATA reference count may become negative under above
race condition, the root cause is we missed to wait page writeback before
setting gcing page private flag, let's fix it.

Fixes: 2d1fe8a8 ("f2fs: fix to tag gcing flag on page during file defragment")
Fixes: 4961acdd ("f2fs: fix to tag gcing flag on page during block migration")
Signed-off-by: default avatarChao Yu <chao@kernel.org>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent 8c1b7879

fs/f2fs/file.c

+4 −0
Original line number Diff line number Diff line
@@ -2807,6 +2807,8 @@ static int f2fs_defragment_range(struct f2fs_sb_info *sbi, 
				goto clear_out;

			}



			f2fs_wait_on_page_writeback(page, DATA, true, true);



			set_page_dirty(page);

			set_page_private_gcing(page);

			f2fs_put_page(page, 1);
@@ -4207,6 +4209,8 @@ static int redirty_blocks(struct inode *inode, pgoff_t page_idx, int len) 
		/* It will never fail, when page has pinned above */

		f2fs_bug_on(F2FS_I_SB(inode), !page);



		f2fs_wait_on_page_writeback(page, DATA, true, true);



		set_page_dirty(page);

		set_page_private_gcing(page);

		f2fs_put_page(page, 1);