vfs: no fallback for ->copy_file_range

Now that we have generic_copy_file_range(), remove it as a fallback
case when offloads fail. This puts the responsibility for executing
fallbacks on the filesystems that implement ->copy_file_range and
allows us to add operational validity checks to
generic_copy_file_range().

Rework vfs_copy_file_range() to call a new do_copy_file_range()
helper to execute the copying callout, and move calls to
generic_file_copy_range() into filesystem methods where they
currently return failures.

[Amir] overlayfs is not responsible of executing the fallback.
It is the responsibility of the underlying filesystem.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
This commit is contained in:
Dave Chinner
2019-06-05 08:04:47 -07:00
committed by Darrick J. Wong
parent f16acc9d9b
commit 64bf5ff58d
5 changed files with 73 additions and 18 deletions

View File

@@ -1595,6 +1595,19 @@ ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
}
EXPORT_SYMBOL(generic_copy_file_range);
static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in,
struct file *file_out, loff_t pos_out,
size_t len, unsigned int flags)
{
if (file_out->f_op->copy_file_range)
return file_out->f_op->copy_file_range(file_in, pos_in,
file_out, pos_out,
len, flags);
return generic_copy_file_range(file_in, pos_in, file_out, pos_out, len,
flags);
}
/*
* copy_file_range() differs from regular file read and write in that it
* specifically allows return partial success. When it does so is up to
@@ -1655,15 +1668,9 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
}
}
if (file_out->f_op->copy_file_range) {
ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out,
pos_out, len, flags);
if (ret != -EOPNOTSUPP)
goto done;
}
ret = generic_copy_file_range(file_in, pos_in, file_out, pos_out, len,
flags);
ret = do_copy_file_range(file_in, pos_in, file_out, pos_out, len,
flags);
WARN_ON_ONCE(ret == -EOPNOTSUPP);
done:
if (ret > 0) {
fsnotify_access(file_in);