The patch below does not apply to the 4.16-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From dc7a10ddee0c56c6d891dd18de5c4ee9869545e0 Mon Sep 17 00:00:00 2001

From: Jaegeuk Kim jaegeuk@kernel.org Date: Fri, 30 Mar 2018 17:58:13 -0700 Subject: [PATCH] f2fs: truncate preallocated blocks in error case

If write is failed, we must deallocate the blocks that we couldn't write.

Cc: stable@vger.kernel.org Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 8068b015ece5..6b94f19b3fa8 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -2911,6 +2911,8 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)

ret = generic_write_checks(iocb, from); if (ret > 0) { + bool preallocated = false; + size_t target_size = 0; int err;

if (iov_iter_fault_in_readable(from, iov_iter_count(from))) @@ -2927,6 +2929,9 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) }

} else { + preallocated = true; + target_size = iocb->ki_pos + iov_iter_count(from); + err = f2fs_preallocate_blocks(iocb, from); if (err) { clear_inode_flag(inode, FI_NO_PREALLOC); @@ -2939,6 +2944,10 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) blk_finish_plug(&plug); clear_inode_flag(inode, FI_NO_PREALLOC);

+ /* if we couldn't write data, we should deallocate blocks. */ + if (preallocated && i_size_read(inode) < target_size) + f2fs_truncate(inode); + if (ret > 0) f2fs_update_iostat(F2FS_I_SB(inode), APP_WRITE_IO, ret); }