From c60ae98c5aa64021751b38ab1313b19d620bf640 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 11 Sep 2026 10:25:04 +0100 Subject: 9p: Fix v9fs_issue_write() to update i_size and remote_i_size Fix v9fs_issue_write() to update i_size and remote_i_size to the new size of the server file if we made it larger, using the start fpos and the count returned by p9_client_write() to calculate the new minimum file size. This assumes that if the 9P server makes a short write (say it hits ENOSPC), a reduced count is returned. Fixes: 5fb70e7275a6 ("netfs, 9p: Implement helpers for new write code") Reported-by: Michael Mulqueen Closes: https://lore.kernel.org/r/fbb9e395-1e07-4212-8f70-23f3cd498074@method-b.uk/ Cc: stable@vger.kernel.org Signed-off-by: David Howells Message-ID: <2226525.1789118704@warthog.procyon.org.uk> Signed-off-by: Dominique Martinet --- fs/9p/vfs_addr.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c index 1ac0b3dcc077..13cf87a5f90c 100644 --- a/fs/9p/vfs_addr.c +++ b/fs/9p/vfs_addr.c @@ -54,11 +54,37 @@ static void v9fs_begin_writeback(struct netfs_io_request *wreq) static void v9fs_issue_write(struct netfs_io_subrequest *subreq) { struct p9_fid *fid = subreq->rreq->netfs_priv; + struct inode *inode = subreq->rreq->inode; + struct netfs_inode *ictx = netfs_inode(inode); int err, len; len = p9_client_write(fid, subreq->start, &subreq->io_iter, &err); - if (len > 0) + if (len > 0) { + uoff_t end = subreq->start + len, i_size, remote, zp; + bool set = false; + + spin_lock(&inode->i_lock); + + /* We can read the sizes directly as we hold i_lock. */ + i_size = inode->i_size; + remote = ictx->_remote_i_size; + zp = ictx->_zero_point; + + if (end > i_size) { + i_size = end; + set = true; + } + if (end > remote) { + remote = end; + set = true; + } + + if (set) + netfs_write_sizes(inode, i_size, remote, zp); + spin_unlock(&inode->i_lock); + __set_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags); + } netfs_write_subrequest_terminated(subreq, len ?: err); } -- cgit v1.2.3