From: David Howells dhowells@redhat.com
[ 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@redhat.com Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Christian Brauner brauner@kernel.org cc: Steve French stfrench@microsoft.com cc: Jens Axboe axboe@kernel.dk 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 Link: https://lore.kernel.org/r/20230522135018.2742245-2-dhowells@redhat.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- mm/filemap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
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);