From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Miklos Szeredi To: linux-unionfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 13/35] ovl: add ovl_read_iter() Date: Mon, 7 May 2018 10:37:45 +0200 Message-Id: <20180507083807.28792-14-mszeredi@redhat.com> In-Reply-To: <20180507083807.28792-1-mszeredi@redhat.com> References: <20180507083807.28792-1-mszeredi@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: Implement stacked reading. Signed-off-by: Miklos Szeredi --- fs/overlayfs/file.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index db8778e7c37a..bbc40a14acf8 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -9,6 +9,7 @@ #include #include #include +#include #include "overlayfs.h" static struct file *ovl_open_realfile(const struct file *file) @@ -129,8 +130,74 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence) i_size_read(realinode)); } +static void ovl_file_accessed(struct file *file) +{ + struct inode *inode, *upperinode; + + if (file->f_flags & O_NOATIME) + return; + + inode = file_inode(file); + upperinode = ovl_inode_upper(inode); + + if (!upperinode) + return; + + if ((!timespec_equal(&inode->i_mtime, &upperinode->i_mtime) || + !timespec_equal(&inode->i_ctime, &upperinode->i_ctime))) { + inode->i_mtime = upperinode->i_mtime; + inode->i_ctime = upperinode->i_ctime; + } + + touch_atime(&file->f_path); +} + +static rwf_t ovl_iocb_to_rwf(struct kiocb *iocb) +{ + int ifl = iocb->ki_flags; + rwf_t flags = 0; + + if (ifl & IOCB_NOWAIT) + flags |= RWF_NOWAIT; + if (ifl & IOCB_HIPRI) + flags |= RWF_HIPRI; + if (ifl & IOCB_DSYNC) + flags |= RWF_DSYNC; + if (ifl & IOCB_SYNC) + flags |= RWF_SYNC; + + return flags; +} + +static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter) +{ + struct file *file = iocb->ki_filp; + struct fd real; + const struct cred *old_cred; + ssize_t ret; + + if (!iov_iter_count(iter)) + return 0; + + ret = ovl_real_fdget(file, &real); + if (ret) + return ret; + + old_cred = ovl_override_creds(file_inode(file)->i_sb); + ret = vfs_iter_read(real.file, iter, &iocb->ki_pos, + ovl_iocb_to_rwf(iocb)); + revert_creds(old_cred); + + ovl_file_accessed(file); + + fdput(real); + + return ret; +} + const struct file_operations ovl_file_operations = { .open = ovl_open, .release = ovl_release, .llseek = ovl_llseek, + .read_iter = ovl_read_iter, }; -- 2.14.3