[PATCH v21 18/30] ext4: Provide a splice-read stub

David Howells
2023-05-20T00:02:00Z

Provide a splice_read stub for Ext4. This does the inode shutdown check
before proceeding. Splicing from DAX files and O_DIRECT fds is handled by
the caller.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Jens Axboe <axboe@kernel.dk>
cc: "Theodore Ts'o" <tytso@mit.edu>
cc: Andreas Dilger <adilger.kernel@dilger.ca>
cc: linux-ext4@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-block@vger.kernel.org
cc: linux-mm@kvack.org
---
fs/ext4/file.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index d101b3b0c7da..9f8bbd9d131c 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -147,6 +147,17 @@ static ssize_t ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
return generic_file_read_iter(iocb, to);
}

+static ssize_t ext4_file_splice_read(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe,
+ size_t len, unsigned int flags)
+{
+ struct inode *inode = file_inode(in);
+
+ if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
+ return -EIO;
+ return generic_file_splice_read(in, ppos, pipe, len, flags);
+}
+
/*
* Called when an inode is released. Note that this is different
* from ext4_file_open: open gets called at every open, but release
@@ -957,7 +968,7 @@ const struct file_operations ext4_file_operations = {
.release = ext4_release_file,
.fsync = ext4_sync_file,
.get_unmapped_area = thp_get_unmapped_area,
- .splice_read = generic_file_splice_read,
+ .splice_read = ext4_file_splice_read,
.splice_write = iter_file_splice_write,
.fallocate = ext4_fallocate,
};