f2fs: fix data corruption issue with hardware encryption
Direct IO can be used in case of hardware encryption. The following
scenario results into data corruption issue in this path -
Thread A - Thread B-
-> write file#1 in direct IO
-> GC gets kicked in
-> GC submitted bio on meta mapping
for file#1, but pending completion
-> write file#1 again with new data
in direct IO
-> GC bio gets completed now
-> GC writes old data to the new
location and thus file#1 is
corrupted.
Fix this by submitting and waiting for pending io on meta mapping
for direct IO case in f2fs_map_blocks().