Commit 20d0a107 authored by Gabriel Krisman Bertazi's avatar Gabriel Krisman Bertazi Committed by Jaegeuk Kim

f2fs: Return EOF on unaligned end of file DIO read

Reading past end of file returns EOF for aligned reads but -EINVAL for
unaligned reads on f2fs.  While documentation is not strict about this
corner case, most filesystem returns EOF on this case, like iomap
filesystems.  This patch consolidates the behavior for f2fs, by making
it return EOF(0).

it can be verified by a read loop on a file that does a partial read
before EOF (A file that doesn't end at an aligned address).  The
following code fails on an unaligned file on f2fs, but not on
btrfs, ext4, and xfs.

  while (done < total) {
    ssize_t delta = pread(fd, buf + done, total - done, off + done);
    if (!delta)
      break;
    ...
  }

It is arguable whether filesystems should actually return EOF or
-EINVAL, but since iomap filesystems support it, and so does the
original DIO code, it seems reasonable to consolidate on that.
Signed-off-by: default avatarGabriel Krisman Bertazi <krisman@collabora.com>
Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk@kernel.org>
parent e2cab031
...@@ -3550,6 +3550,9 @@ static int check_direct_IO(struct inode *inode, struct iov_iter *iter, ...@@ -3550,6 +3550,9 @@ static int check_direct_IO(struct inode *inode, struct iov_iter *iter,
unsigned long align = offset | iov_iter_alignment(iter); unsigned long align = offset | iov_iter_alignment(iter);
struct block_device *bdev = inode->i_sb->s_bdev; struct block_device *bdev = inode->i_sb->s_bdev;
if (iov_iter_rw(iter) == READ && offset >= i_size_read(inode))
return 1;
if (align & blocksize_mask) { if (align & blocksize_mask) {
if (bdev) if (bdev)
blkbits = blksize_bits(bdev_logical_block_size(bdev)); blkbits = blksize_bits(bdev_logical_block_size(bdev));
......
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