diff mbox series

[v20,01/32] splice: Fix filemap of a blockdev

Message ID 20230519074047.1739879-2-dhowells@redhat.com (mailing list archive)
State New
Headers show
Series splice, block: Use page pinning and kill ITER_PIPE | expand

Commit Message

David Howells May 19, 2023, 7:40 a.m. UTC 
Fix filemap_splice_read() to use file->f_mapping->host, not file->f_inode,
as the source of the file size because in the case of a block device,
file->f_inode points to the block-special file (which is typically 0
length) and not the backing store.

Fixes: 07073eb01c5f ("splice: Add a func to do a splice from a buffered file without ITER_PIPE")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Steve French <stfrench@microsoft.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: David Hildenbrand <david@redhat.com>
cc: John Hubbard <jhubbard@nvidia.com>
cc: linux-mm@kvack.org
cc: linux-block@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
---
 mm/filemap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Christoph Hellwig May 19, 2023, 8:06 a.m. UTC | #1 
Looks good:

Reviewed-by: Christoph Hellwig <hch@lst.de>

But this really needs to be sent standalone so that it can get picked
up for 6.4 and -stable.
David Howells May 19, 2023, 9:11 a.m. UTC | #2 
Christoph Hellwig <hch@infradead.org> wrote:

> 
> But this really needs to be sent standalone so that it can get picked
> up for 6.4 and -stable.

Note that only cifs is actually using that code at the moment.

David
diff mbox series

Patch

diff --git a/mm/filemap.c b/mm/filemap.c
index b4c9bd368b7e..a2006936a6ae 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2900,7 +2900,7 @@  ssize_t filemap_splice_read(struct file *in, loff_t *ppos,
 	do {
 		cond_resched();
 
-		if (*ppos >= i_size_read(file_inode(in)))
+		if (*ppos >= i_size_read(in->f_mapping->host))
 			break;
 
 		iocb.ki_pos = *ppos;
@@ -2916,7 +2916,7 @@  ssize_t filemap_splice_read(struct file *in, loff_t *ppos,
 		 * part of the page is not copied back to userspace (unless
 		 * another truncate extends the file - this is desired though).
 		 */
-		isize = i_size_read(file_inode(in));
+		isize = i_size_read(in->f_mapping->host);
 		if (unlikely(*ppos >= isize))
 			break;
 		end_offset = min_t(loff_t, isize, *ppos + len);