f2fs: use adjusted write range after f2fs_write_checks()

generic_write_checks() in f2fs_write_checks() can adjust iocb->ki_pos
for append writes and truncate the iterator to limit the number of bytes
to write.

In f2fs_file_write_iter(), the pinned-file overwrite check currently
uses the position and count saved before f2fs_write_checks(), so it
can check a range different from the actual write range.

The forced buffered I/O cleanup also uses orig_pos saved before
f2fs_write_checks(). For O_APPEND writes, this can make the cleanup
flush and invalidate the wrong page cache range.

Move the pinned-file overwrite check after f2fs_write_checks() and use
the adjusted iocb->ki_pos and iov_iter_count(from). Also save the
adjusted write position and use it for the forced buffered I/O cleanup.

Fixes: 3fdd89b452c2 ("f2fs: prevent writing without fallocate() for pinned files")
Fixes: 92318f20d703 ("f2fs: preserve direct write semantics when buffering is forced")
Signed-off-by: Seongjae Jeong <jsjlee1020@gmail.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

0 files changed, 0 insertions, 0 deletions