There are two threads:
f2fs_delete_entry() get_new_data_page()
f2fs_reserve_block()
dn.blkaddr = XXX
lock_page(dentry_block)
truncate_hole()
dn.blkaddr = NULL
unlock_page(dentry_block)
lock_page(dentry_block)
fill the block from XXX address
add new dentries
unlock_page(dentry_block)
Later, f2fs_write_data_page() will truncate the dentry_block, since
its block address is NULL.
The reason for this was due to the wrong lock order.
In this case, we should do f2fs_reserve_block() after locking its dentry block.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
01f28610a1