From mboxrd@z Thu Jan 1 00:00:00 1970 From: Miklos Szeredi Subject: [PATCH v2 14/35] ovl: add ovl_write_iter() Date: Mon, 7 May 2018 10:37:46 +0200 Message-ID: <20180507083807.28792-15-mszeredi@redhat.com> References: <20180507083807.28792-1-mszeredi@redhat.com> Return-path: In-Reply-To: <20180507083807.28792-1-mszeredi@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-unionfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-unionfs@vger.kernel.org Implement stacked writes. Signed-off-by: Miklos Szeredi --- fs/overlayfs/file.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index bbc40a14acf8..a7af56861aa5 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -195,9 +195,48 @@ static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter) return ret; } +static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter) +{ + struct file *file = iocb->ki_filp; + struct inode *inode = file_inode(file); + struct fd real; + const struct cred *old_cred; + ssize_t ret; + + if (!iov_iter_count(iter)) + return 0; + + inode_lock(inode); + /* Update mode */ + ovl_copyattr(ovl_inode_real(inode), inode); + ret = file_remove_privs(file); + if (ret) + goto out_unlock; + + ret = ovl_real_fdget(file, &real); + if (ret) + goto out_unlock; + + old_cred = ovl_override_creds(file_inode(file)->i_sb); + ret = vfs_iter_write(real.file, iter, &iocb->ki_pos, + ovl_iocb_to_rwf(iocb)); + revert_creds(old_cred); + + /* Update size */ + ovl_copyattr(ovl_inode_real(inode), inode); + + fdput(real); + +out_unlock: + inode_unlock(inode); + + return ret; +} + const struct file_operations ovl_file_operations = { .open = ovl_open, .release = ovl_release, .llseek = ovl_llseek, .read_iter = ovl_read_iter, + .write_iter = ovl_write_iter, }; -- 2.14.3