Patch "splice: Fix filemap_splice_read() to use the correct inode" has been added to the 6.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    splice: Fix filemap_splice_read() to use the correct inode

to the 6.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     splice-fix-filemap_splice_read-to-use-the-correct-in.patch
and it can be found in the queue-6.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 05e74515e4592d1a531df9f02877b130c49e309f
Author: David Howells <dhowells@xxxxxxxxxx>
Date:   Mon May 22 14:49:48 2023 +0100

    splice: Fix filemap_splice_read() to use the correct inode
    
    [ Upstream commit c37222082f23c456664d1c3182a714670ab8f9a4 ]
    
    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@xxxxxxxxxx>
    Reviewed-by: Christoph Hellwig <hch@xxxxxx>
    Reviewed-by: Christian Brauner <brauner@xxxxxxxxxx>
    cc: Steve French <stfrench@xxxxxxxxxxxxx>
    cc: Jens Axboe <axboe@xxxxxxxxx>
    cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
    cc: David Hildenbrand <david@xxxxxxxxxx>
    cc: John Hubbard <jhubbard@xxxxxxxxxx>
    cc: linux-mm@xxxxxxxxx
    cc: linux-block@xxxxxxxxxxxxxxx
    cc: linux-fsdevel@xxxxxxxxxxxxxxx
    Link: https://lore.kernel.org/r/20230522135018.2742245-2-dhowells@xxxxxxxxxx
    Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/mm/filemap.c b/mm/filemap.c
index 83dda76d1fc36..8abce63b259c9 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2906,7 +2906,7 @@ 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;
@@ -2922,7 +2922,7 @@ 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);