f2fs: avoid race condition in handling wait_io
__submit_merged_bio f2fs_write_end_io f2fs_write_end_io
wait_io = X wait_io = x
complete(X) complete(X)
wait_io = NULL
wait_for_completion()
free(X)
spin_lock(X)
kernel panic
In order to avoid this, this patch removes the wait_io facility.
Instead, we can use wait_on_all_pages_writeback(sbi) to wait for end_ios.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index ca514d5..dd6a357 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -978,6 +978,9 @@
/* Here, we only have one bio having CP pack */
sync_meta_pages(sbi, META_FLUSH, LONG_MAX);
+ /* wait for previous submitted meta pages writeback */
+ wait_on_all_pages_writeback(sbi);
+
release_dirty_inode(sbi);
if (unlikely(f2fs_cp_error(sbi)))