On 23/07/20 09:57AM, Christoph Hellwig wrote:
+/* Copy source offset from source block device to destination block
+ * device. Returns the length of bytes copied.
+ */
+ssize_t blkdev_copy_offload_failfast(
+ struct block_device *bdev_in, loff_t pos_in,
+ struct block_device *bdev_out, loff_t pos_out,
+ size_t len, gfp_t gfp_mask)
This is an odd and very misnamed interface.
Either we have a klkdev_copy() interface that automatically falls back
to a fallback (maybe with an opt-out), or we have separate
blkdev_copy_offload/blkdev_copy_emulated interface and let the caller
decide. But none of that really is "failfast".
Also this needs to go into the helpers patch and not a patch that is
supposed to just wire copying up for block device node.
Acked.
index b07de77ef126..d27148a2543f 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1447,7 +1447,8 @@ static int generic_copy_file_checks(struct file *file_in, loff_t pos_in,
return -EOVERFLOW;
/* Shorten the copy to EOF */
- size_in = i_size_read(inode_in);
+ size_in = i_size_read(file_in->f_mapping->host);
generic_copy_file_checks needs to be fixed to use ->mapping->host both
or inode_in and inode_out at the top of the file instead of this
band aid. And that needs to be a separate patch with a Fixes tag.
Addressed below.
@@ -1708,7 +1709,9 @@ int generic_file_rw_checks(struct file *file_in, struct file *file_out)
/* Don't copy dirs, pipes, sockets... */
if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
return -EISDIR;
- if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
+
+ if ((!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode)) &&
+ (!S_ISBLK(inode_in->i_mode) || !S_ISBLK(inode_out->i_mode)))
This is using weird indentation, and might also not be doing
exactly what we want. I think the better thing to do here is to:
1) check for the accetable types only on the in inode
2) have a check that the mode matches for the in and out inodes
And please do this as a separate prep patch instead of hiding it here.
Agreed. We will send a separate patch, that enables copy_file_range on
block devices.
Thank you,
Nitesh Shetty
