mcoverlayfs: add overlayfs of the original(kernel 4.0.9)
This commit is contained in:
Yoichi Umezawa
@ -4,6 +4,7 @@ MANDIR = @MANDIR@
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all::
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@(cd executer/kernel/mcctrl; make modules)
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@(cd executer/kernel/mcoverlayfs; make modules)
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@(cd executer/user; make)
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@case "$(TARGET)" in \
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attached-mic | builtin-x86 | builtin-mic | smp-x86) \
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@ -17,6 +18,7 @@ all::
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install::
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@(cd executer/kernel/mcctrl; make install)
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@(cd executer/kernel/mcoverlayfs; make install)
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@(cd executer/user; make install)
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@case "$(TARGET)" in \
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attached-mic | builtin-x86 | builtin-mic | smp-x86) \
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@ -57,6 +59,7 @@ install::
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clean::
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@(cd executer/kernel/mcctrl; make clean)
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@(cd executer/kernel/mcoverlayfs; make clean)
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@(cd executer/user; make clean)
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@case "$(TARGET)" in \
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attached-mic | builtin-x86 | builtin-mic | smp-x86) \
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3
configure
vendored
3
configure
vendored
@ -3816,7 +3816,7 @@ TARGET="$WITH_TARGET"
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ac_config_files="$ac_config_files Makefile executer/user/Makefile executer/kernel/mcctrl/Makefile kernel/Makefile kernel/Makefile.build arch/x86/tools/mcreboot-attached-mic.sh arch/x86/tools/mcshutdown-attached-mic.sh arch/x86/tools/mcreboot-builtin-x86.sh arch/x86/tools/mcreboot-smp-x86.sh arch/x86/tools/mcstop+release-smp-x86.sh arch/x86/tools/mcshutdown-builtin-x86.sh arch/x86/tools/mcreboot.1:arch/x86/tools/mcreboot.1in"
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ac_config_files="$ac_config_files Makefile executer/user/Makefile executer/kernel/mcctrl/Makefile executer/kernel/mcoverlayfs/Makefile kernel/Makefile kernel/Makefile.build arch/x86/tools/mcreboot-attached-mic.sh arch/x86/tools/mcshutdown-attached-mic.sh arch/x86/tools/mcreboot-builtin-x86.sh arch/x86/tools/mcreboot-smp-x86.sh arch/x86/tools/mcstop+release-smp-x86.sh arch/x86/tools/mcshutdown-builtin-x86.sh arch/x86/tools/mcreboot.1:arch/x86/tools/mcreboot.1in"
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if test "x$enable_dcfa" = xyes; then :
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@ -4533,6 +4533,7 @@ do
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"Makefile") CONFIG_FILES="$CONFIG_FILES Makefile" ;;
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"executer/user/Makefile") CONFIG_FILES="$CONFIG_FILES executer/user/Makefile" ;;
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"executer/kernel/mcctrl/Makefile") CONFIG_FILES="$CONFIG_FILES executer/kernel/mcctrl/Makefile" ;;
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"executer/kernel/mcoverlayfs/Makefile") CONFIG_FILES="$CONFIG_FILES executer/kernel/mcoverlayfs/Makefile" ;;
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"kernel/Makefile") CONFIG_FILES="$CONFIG_FILES kernel/Makefile" ;;
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"kernel/Makefile.build") CONFIG_FILES="$CONFIG_FILES kernel/Makefile.build" ;;
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"arch/x86/tools/mcreboot-attached-mic.sh") CONFIG_FILES="$CONFIG_FILES arch/x86/tools/mcreboot-attached-mic.sh" ;;
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@ -161,6 +161,7 @@ AC_CONFIG_FILES([
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Makefile
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executer/user/Makefile
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executer/kernel/mcctrl/Makefile
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executer/kernel/mcoverlayfs/Makefile
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kernel/Makefile
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kernel/Makefile.build
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arch/x86/tools/mcreboot-attached-mic.sh
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27
executer/kernel/mcoverlayfs/Makefile.in
Normal file
27
executer/kernel/mcoverlayfs/Makefile.in
Normal file
@ -0,0 +1,27 @@
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KDIR ?= @KDIR@
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ARCH ?= @ARCH@
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KMODDIR=@KMODDIR@
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RELEASE=$(shell uname -r)
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ENABLE_BUILD=$(shell if [[ ${RELEASE} =~ ^4.* ]]; then echo "yes"; fi)
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obj-m += mcoverlay.o
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mcoverlay-y := copy_up.o dir.o inode.o readdir.o super.o
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.PHONY: clean install modules
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modules:
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ifeq ($(ENABLE_BUILD),yes)
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$(MAKE) -C $(KDIR) M=$(PWD) SUBDIRS=$(PWD) ARCH=$(ARCH) modules
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endif
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clean:
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$(RM) .*.cmd *.mod.c *.o *.ko* Module.symvers modules.order -r .tmp*
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install:
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ifeq ($(ENABLE_BUILD),yes)
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mkdir -p -m 755 $(KMODDIR)
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install -m 644 mcoverlay.ko $(KMODDIR)
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endif
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416
executer/kernel/mcoverlayfs/copy_up.c
Normal file
416
executer/kernel/mcoverlayfs/copy_up.c
Normal file
@ -0,0 +1,416 @@
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/*
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*
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* Copyright (C) 2011 Novell Inc.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <linux/file.h>
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#include <linux/splice.h>
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#include <linux/xattr.h>
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#include <linux/security.h>
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#include <linux/uaccess.h>
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#include <linux/sched.h>
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#include <linux/namei.h>
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#include "overlayfs.h"
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#define OVL_COPY_UP_CHUNK_SIZE (1 << 20)
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int ovl_copy_xattr(struct dentry *old, struct dentry *new)
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{
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ssize_t list_size, size;
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char *buf, *name, *value;
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int error;
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if (!old->d_inode->i_op->getxattr ||
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!new->d_inode->i_op->getxattr)
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return 0;
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list_size = vfs_listxattr(old, NULL, 0);
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if (list_size <= 0) {
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if (list_size == -EOPNOTSUPP)
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return 0;
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return list_size;
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}
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buf = kzalloc(list_size, GFP_KERNEL);
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if (!buf)
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return -ENOMEM;
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error = -ENOMEM;
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value = kmalloc(XATTR_SIZE_MAX, GFP_KERNEL);
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if (!value)
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goto out;
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list_size = vfs_listxattr(old, buf, list_size);
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if (list_size <= 0) {
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error = list_size;
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goto out_free_value;
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}
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for (name = buf; name < (buf + list_size); name += strlen(name) + 1) {
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size = vfs_getxattr(old, name, value, XATTR_SIZE_MAX);
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if (size <= 0) {
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error = size;
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goto out_free_value;
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}
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error = vfs_setxattr(new, name, value, size, 0);
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if (error)
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goto out_free_value;
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}
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out_free_value:
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kfree(value);
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out:
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kfree(buf);
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return error;
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}
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static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
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{
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struct file *old_file;
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struct file *new_file;
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loff_t old_pos = 0;
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loff_t new_pos = 0;
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int error = 0;
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if (len == 0)
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return 0;
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old_file = ovl_path_open(old, O_RDONLY);
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if (IS_ERR(old_file))
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return PTR_ERR(old_file);
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new_file = ovl_path_open(new, O_WRONLY);
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if (IS_ERR(new_file)) {
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error = PTR_ERR(new_file);
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goto out_fput;
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}
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/* FIXME: copy up sparse files efficiently */
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while (len) {
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size_t this_len = OVL_COPY_UP_CHUNK_SIZE;
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long bytes;
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if (len < this_len)
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this_len = len;
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if (signal_pending_state(TASK_KILLABLE, current)) {
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error = -EINTR;
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break;
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}
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bytes = do_splice_direct(old_file, &old_pos,
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new_file, &new_pos,
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this_len, SPLICE_F_MOVE);
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if (bytes <= 0) {
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error = bytes;
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break;
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}
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WARN_ON(old_pos != new_pos);
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len -= bytes;
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}
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fput(new_file);
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out_fput:
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fput(old_file);
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return error;
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}
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static char *ovl_read_symlink(struct dentry *realdentry)
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{
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int res;
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char *buf;
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struct inode *inode = realdentry->d_inode;
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mm_segment_t old_fs;
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res = -EINVAL;
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if (!inode->i_op->readlink)
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goto err;
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res = -ENOMEM;
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buf = (char *) __get_free_page(GFP_KERNEL);
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if (!buf)
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goto err;
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old_fs = get_fs();
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set_fs(get_ds());
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/* The cast to a user pointer is valid due to the set_fs() */
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res = inode->i_op->readlink(realdentry,
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(char __user *)buf, PAGE_SIZE - 1);
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set_fs(old_fs);
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if (res < 0) {
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free_page((unsigned long) buf);
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goto err;
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}
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buf[res] = '\0';
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return buf;
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err:
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return ERR_PTR(res);
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}
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static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat)
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{
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struct iattr attr = {
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.ia_valid =
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ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET,
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.ia_atime = stat->atime,
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.ia_mtime = stat->mtime,
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};
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return notify_change(upperdentry, &attr, NULL);
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}
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int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat)
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{
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int err = 0;
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if (!S_ISLNK(stat->mode)) {
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struct iattr attr = {
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.ia_valid = ATTR_MODE,
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.ia_mode = stat->mode,
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};
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err = notify_change(upperdentry, &attr, NULL);
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}
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if (!err) {
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struct iattr attr = {
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.ia_valid = ATTR_UID | ATTR_GID,
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.ia_uid = stat->uid,
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.ia_gid = stat->gid,
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};
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err = notify_change(upperdentry, &attr, NULL);
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}
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if (!err)
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ovl_set_timestamps(upperdentry, stat);
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return err;
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}
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static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
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struct dentry *dentry, struct path *lowerpath,
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struct kstat *stat, struct iattr *attr,
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const char *link)
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{
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struct inode *wdir = workdir->d_inode;
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struct inode *udir = upperdir->d_inode;
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struct dentry *newdentry = NULL;
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struct dentry *upper = NULL;
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umode_t mode = stat->mode;
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int err;
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newdentry = ovl_lookup_temp(workdir, dentry);
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err = PTR_ERR(newdentry);
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if (IS_ERR(newdentry))
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goto out;
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upper = lookup_one_len(dentry->d_name.name, upperdir,
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dentry->d_name.len);
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err = PTR_ERR(upper);
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if (IS_ERR(upper))
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goto out1;
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/* Can't properly set mode on creation because of the umask */
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stat->mode &= S_IFMT;
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err = ovl_create_real(wdir, newdentry, stat, link, NULL, true);
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stat->mode = mode;
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if (err)
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goto out2;
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if (S_ISREG(stat->mode)) {
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struct path upperpath;
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ovl_path_upper(dentry, &upperpath);
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BUG_ON(upperpath.dentry != NULL);
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upperpath.dentry = newdentry;
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err = ovl_copy_up_data(lowerpath, &upperpath, stat->size);
|
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if (err)
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goto out_cleanup;
|
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}
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err = ovl_copy_xattr(lowerpath->dentry, newdentry);
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if (err)
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goto out_cleanup;
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mutex_lock(&newdentry->d_inode->i_mutex);
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||||
err = ovl_set_attr(newdentry, stat);
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if (!err && attr)
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err = notify_change(newdentry, attr, NULL);
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mutex_unlock(&newdentry->d_inode->i_mutex);
|
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if (err)
|
||||
goto out_cleanup;
|
||||
|
||||
err = ovl_do_rename(wdir, newdentry, udir, upper, 0);
|
||||
if (err)
|
||||
goto out_cleanup;
|
||||
|
||||
ovl_dentry_update(dentry, newdentry);
|
||||
newdentry = NULL;
|
||||
|
||||
/*
|
||||
* Non-directores become opaque when copied up.
|
||||
*/
|
||||
if (!S_ISDIR(stat->mode))
|
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ovl_dentry_set_opaque(dentry, true);
|
||||
out2:
|
||||
dput(upper);
|
||||
out1:
|
||||
dput(newdentry);
|
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out:
|
||||
return err;
|
||||
|
||||
out_cleanup:
|
||||
ovl_cleanup(wdir, newdentry);
|
||||
goto out;
|
||||
}
|
||||
|
||||
/*
|
||||
* Copy up a single dentry
|
||||
*
|
||||
* Directory renames only allowed on "pure upper" (already created on
|
||||
* upper filesystem, never copied up). Directories which are on lower or
|
||||
* are merged may not be renamed. For these -EXDEV is returned and
|
||||
* userspace has to deal with it. This means, when copying up a
|
||||
* directory we can rely on it and ancestors being stable.
|
||||
*
|
||||
* Non-directory renames start with copy up of source if necessary. The
|
||||
* actual rename will only proceed once the copy up was successful. Copy
|
||||
* up uses upper parent i_mutex for exclusion. Since rename can change
|
||||
* d_parent it is possible that the copy up will lock the old parent. At
|
||||
* that point the file will have already been copied up anyway.
|
||||
*/
|
||||
int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
|
||||
struct path *lowerpath, struct kstat *stat,
|
||||
struct iattr *attr)
|
||||
{
|
||||
struct dentry *workdir = ovl_workdir(dentry);
|
||||
int err;
|
||||
struct kstat pstat;
|
||||
struct path parentpath;
|
||||
struct dentry *upperdir;
|
||||
struct dentry *upperdentry;
|
||||
const struct cred *old_cred;
|
||||
struct cred *override_cred;
|
||||
char *link = NULL;
|
||||
|
||||
if (WARN_ON(!workdir))
|
||||
return -EROFS;
|
||||
|
||||
ovl_path_upper(parent, &parentpath);
|
||||
upperdir = parentpath.dentry;
|
||||
|
||||
err = vfs_getattr(&parentpath, &pstat);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
if (S_ISLNK(stat->mode)) {
|
||||
link = ovl_read_symlink(lowerpath->dentry);
|
||||
if (IS_ERR(link))
|
||||
return PTR_ERR(link);
|
||||
}
|
||||
|
||||
err = -ENOMEM;
|
||||
override_cred = prepare_creds();
|
||||
if (!override_cred)
|
||||
goto out_free_link;
|
||||
|
||||
override_cred->fsuid = stat->uid;
|
||||
override_cred->fsgid = stat->gid;
|
||||
/*
|
||||
* CAP_SYS_ADMIN for copying up extended attributes
|
||||
* CAP_DAC_OVERRIDE for create
|
||||
* CAP_FOWNER for chmod, timestamp update
|
||||
* CAP_FSETID for chmod
|
||||
* CAP_CHOWN for chown
|
||||
* CAP_MKNOD for mknod
|
||||
*/
|
||||
cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN);
|
||||
cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
|
||||
cap_raise(override_cred->cap_effective, CAP_FOWNER);
|
||||
cap_raise(override_cred->cap_effective, CAP_FSETID);
|
||||
cap_raise(override_cred->cap_effective, CAP_CHOWN);
|
||||
cap_raise(override_cred->cap_effective, CAP_MKNOD);
|
||||
old_cred = override_creds(override_cred);
|
||||
|
||||
err = -EIO;
|
||||
if (lock_rename(workdir, upperdir) != NULL) {
|
||||
pr_err("overlayfs: failed to lock workdir+upperdir\n");
|
||||
goto out_unlock;
|
||||
}
|
||||
upperdentry = ovl_dentry_upper(dentry);
|
||||
if (upperdentry) {
|
||||
unlock_rename(workdir, upperdir);
|
||||
err = 0;
|
||||
/* Raced with another copy-up? Do the setattr here */
|
||||
if (attr) {
|
||||
mutex_lock(&upperdentry->d_inode->i_mutex);
|
||||
err = notify_change(upperdentry, attr, NULL);
|
||||
mutex_unlock(&upperdentry->d_inode->i_mutex);
|
||||
}
|
||||
goto out_put_cred;
|
||||
}
|
||||
|
||||
err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath,
|
||||
stat, attr, link);
|
||||
if (!err) {
|
||||
/* Restore timestamps on parent (best effort) */
|
||||
ovl_set_timestamps(upperdir, &pstat);
|
||||
}
|
||||
out_unlock:
|
||||
unlock_rename(workdir, upperdir);
|
||||
out_put_cred:
|
||||
revert_creds(old_cred);
|
||||
put_cred(override_cred);
|
||||
|
||||
out_free_link:
|
||||
if (link)
|
||||
free_page((unsigned long) link);
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
int ovl_copy_up(struct dentry *dentry)
|
||||
{
|
||||
int err;
|
||||
|
||||
err = 0;
|
||||
while (!err) {
|
||||
struct dentry *next;
|
||||
struct dentry *parent;
|
||||
struct path lowerpath;
|
||||
struct kstat stat;
|
||||
enum ovl_path_type type = ovl_path_type(dentry);
|
||||
|
||||
if (OVL_TYPE_UPPER(type))
|
||||
break;
|
||||
|
||||
next = dget(dentry);
|
||||
/* find the topmost dentry not yet copied up */
|
||||
for (;;) {
|
||||
parent = dget_parent(next);
|
||||
|
||||
type = ovl_path_type(parent);
|
||||
if (OVL_TYPE_UPPER(type))
|
||||
break;
|
||||
|
||||
dput(next);
|
||||
next = parent;
|
||||
}
|
||||
|
||||
ovl_path_lower(next, &lowerpath);
|
||||
err = vfs_getattr(&lowerpath, &stat);
|
||||
if (!err)
|
||||
err = ovl_copy_up_one(parent, next, &lowerpath, &stat, NULL);
|
||||
|
||||
dput(parent);
|
||||
dput(next);
|
||||
}
|
||||
|
||||
return err;
|
||||
}
|
||||
951
executer/kernel/mcoverlayfs/dir.c
Normal file
951
executer/kernel/mcoverlayfs/dir.c
Normal file
@ -0,0 +1,951 @@
|
||||
/*
|
||||
*
|
||||
* Copyright (C) 2011 Novell Inc.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify it
|
||||
* under the terms of the GNU General Public License version 2 as published by
|
||||
* the Free Software Foundation.
|
||||
*/
|
||||
|
||||
#include <linux/fs.h>
|
||||
#include <linux/namei.h>
|
||||
#include <linux/xattr.h>
|
||||
#include <linux/security.h>
|
||||
#include <linux/cred.h>
|
||||
#include "overlayfs.h"
|
||||
|
||||
void ovl_cleanup(struct inode *wdir, struct dentry *wdentry)
|
||||
{
|
||||
int err;
|
||||
|
||||
dget(wdentry);
|
||||
if (d_is_dir(wdentry))
|
||||
err = ovl_do_rmdir(wdir, wdentry);
|
||||
else
|
||||
err = ovl_do_unlink(wdir, wdentry);
|
||||
dput(wdentry);
|
||||
|
||||
if (err) {
|
||||
pr_err("overlayfs: cleanup of '%pd2' failed (%i)\n",
|
||||
wdentry, err);
|
||||
}
|
||||
}
|
||||
|
||||
struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry)
|
||||
{
|
||||
struct dentry *temp;
|
||||
char name[20];
|
||||
|
||||
snprintf(name, sizeof(name), "#%lx", (unsigned long) dentry);
|
||||
|
||||
temp = lookup_one_len(name, workdir, strlen(name));
|
||||
if (!IS_ERR(temp) && temp->d_inode) {
|
||||
pr_err("overlayfs: workdir/%s already exists\n", name);
|
||||
dput(temp);
|
||||
temp = ERR_PTR(-EIO);
|
||||
}
|
||||
|
||||
return temp;
|
||||
}
|
||||
|
||||
/* caller holds i_mutex on workdir */
|
||||
static struct dentry *ovl_whiteout(struct dentry *workdir,
|
||||
struct dentry *dentry)
|
||||
{
|
||||
int err;
|
||||
struct dentry *whiteout;
|
||||
struct inode *wdir = workdir->d_inode;
|
||||
|
||||
whiteout = ovl_lookup_temp(workdir, dentry);
|
||||
if (IS_ERR(whiteout))
|
||||
return whiteout;
|
||||
|
||||
err = ovl_do_whiteout(wdir, whiteout);
|
||||
if (err) {
|
||||
dput(whiteout);
|
||||
whiteout = ERR_PTR(err);
|
||||
}
|
||||
|
||||
return whiteout;
|
||||
}
|
||||
|
||||
int ovl_create_real(struct inode *dir, struct dentry *newdentry,
|
||||
struct kstat *stat, const char *link,
|
||||
struct dentry *hardlink, bool debug)
|
||||
{
|
||||
int err;
|
||||
|
||||
if (newdentry->d_inode)
|
||||
return -ESTALE;
|
||||
|
||||
if (hardlink) {
|
||||
err = ovl_do_link(hardlink, dir, newdentry, debug);
|
||||
} else {
|
||||
switch (stat->mode & S_IFMT) {
|
||||
case S_IFREG:
|
||||
err = ovl_do_create(dir, newdentry, stat->mode, debug);
|
||||
break;
|
||||
|
||||
case S_IFDIR:
|
||||
err = ovl_do_mkdir(dir, newdentry, stat->mode, debug);
|
||||
break;
|
||||
|
||||
case S_IFCHR:
|
||||
case S_IFBLK:
|
||||
case S_IFIFO:
|
||||
case S_IFSOCK:
|
||||
err = ovl_do_mknod(dir, newdentry,
|
||||
stat->mode, stat->rdev, debug);
|
||||
break;
|
||||
|
||||
case S_IFLNK:
|
||||
err = ovl_do_symlink(dir, newdentry, link, debug);
|
||||
break;
|
||||
|
||||
default:
|
||||
err = -EPERM;
|
||||
}
|
||||
}
|
||||
if (!err && WARN_ON(!newdentry->d_inode)) {
|
||||
/*
|
||||
* Not quite sure if non-instantiated dentry is legal or not.
|
||||
* VFS doesn't seem to care so check and warn here.
|
||||
*/
|
||||
err = -ENOENT;
|
||||
}
|
||||
return err;
|
||||
}
|
||||
|
||||
static int ovl_set_opaque(struct dentry *upperdentry)
|
||||
{
|
||||
return ovl_do_setxattr(upperdentry, OVL_XATTR_OPAQUE, "y", 1, 0);
|
||||
}
|
||||
|
||||
static void ovl_remove_opaque(struct dentry *upperdentry)
|
||||
{
|
||||
int err;
|
||||
|
||||
err = ovl_do_removexattr(upperdentry, OVL_XATTR_OPAQUE);
|
||||
if (err) {
|
||||
pr_warn("overlayfs: failed to remove opaque from '%s' (%i)\n",
|
||||
upperdentry->d_name.name, err);
|
||||
}
|
||||
}
|
||||
|
||||
static int ovl_dir_getattr(struct vfsmount *mnt, struct dentry *dentry,
|
||||
struct kstat *stat)
|
||||
{
|
||||
int err;
|
||||
enum ovl_path_type type;
|
||||
struct path realpath;
|
||||
|
||||
type = ovl_path_real(dentry, &realpath);
|
||||
err = vfs_getattr(&realpath, stat);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
stat->dev = dentry->d_sb->s_dev;
|
||||
stat->ino = dentry->d_inode->i_ino;
|
||||
|
||||
/*
|
||||
* It's probably not worth it to count subdirs to get the
|
||||
* correct link count. nlink=1 seems to pacify 'find' and
|
||||
* other utilities.
|
||||
*/
|
||||
if (OVL_TYPE_MERGE(type))
|
||||
stat->nlink = 1;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
|
||||
struct kstat *stat, const char *link,
|
||||
struct dentry *hardlink)
|
||||
{
|
||||
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
|
||||
struct inode *udir = upperdir->d_inode;
|
||||
struct dentry *newdentry;
|
||||
int err;
|
||||
|
||||
mutex_lock_nested(&udir->i_mutex, I_MUTEX_PARENT);
|
||||
newdentry = lookup_one_len(dentry->d_name.name, upperdir,
|
||||
dentry->d_name.len);
|
||||
err = PTR_ERR(newdentry);
|
||||
if (IS_ERR(newdentry))
|
||||
goto out_unlock;
|
||||
err = ovl_create_real(udir, newdentry, stat, link, hardlink, false);
|
||||
if (err)
|
||||
goto out_dput;
|
||||
|
||||
ovl_dentry_version_inc(dentry->d_parent);
|
||||
ovl_dentry_update(dentry, newdentry);
|
||||
ovl_copyattr(newdentry->d_inode, inode);
|
||||
d_instantiate(dentry, inode);
|
||||
newdentry = NULL;
|
||||
out_dput:
|
||||
dput(newdentry);
|
||||
out_unlock:
|
||||
mutex_unlock(&udir->i_mutex);
|
||||
return err;
|
||||
}
|
||||
|
||||
static int ovl_lock_rename_workdir(struct dentry *workdir,
|
||||
struct dentry *upperdir)
|
||||
{
|
||||
/* Workdir should not be the same as upperdir */
|
||||
if (workdir == upperdir)
|
||||
goto err;
|
||||
|
||||
/* Workdir should not be subdir of upperdir and vice versa */
|
||||
if (lock_rename(workdir, upperdir) != NULL)
|
||||
goto err_unlock;
|
||||
|
||||
return 0;
|
||||
|
||||
err_unlock:
|
||||
unlock_rename(workdir, upperdir);
|
||||
err:
|
||||
pr_err("overlayfs: failed to lock workdir+upperdir\n");
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
static struct dentry *ovl_clear_empty(struct dentry *dentry,
|
||||
struct list_head *list)
|
||||
{
|
||||
struct dentry *workdir = ovl_workdir(dentry);
|
||||
struct inode *wdir = workdir->d_inode;
|
||||
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
|
||||
struct inode *udir = upperdir->d_inode;
|
||||
struct path upperpath;
|
||||
struct dentry *upper;
|
||||
struct dentry *opaquedir;
|
||||
struct kstat stat;
|
||||
int err;
|
||||
|
||||
if (WARN_ON(!workdir))
|
||||
return ERR_PTR(-EROFS);
|
||||
|
||||
err = ovl_lock_rename_workdir(workdir, upperdir);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
ovl_path_upper(dentry, &upperpath);
|
||||
err = vfs_getattr(&upperpath, &stat);
|
||||
if (err)
|
||||
goto out_unlock;
|
||||
|
||||
err = -ESTALE;
|
||||
if (!S_ISDIR(stat.mode))
|
||||
goto out_unlock;
|
||||
upper = upperpath.dentry;
|
||||
if (upper->d_parent->d_inode != udir)
|
||||
goto out_unlock;
|
||||
|
||||
opaquedir = ovl_lookup_temp(workdir, dentry);
|
||||
err = PTR_ERR(opaquedir);
|
||||
if (IS_ERR(opaquedir))
|
||||
goto out_unlock;
|
||||
|
||||
err = ovl_create_real(wdir, opaquedir, &stat, NULL, NULL, true);
|
||||
if (err)
|
||||
goto out_dput;
|
||||
|
||||
err = ovl_copy_xattr(upper, opaquedir);
|
||||
if (err)
|
||||
goto out_cleanup;
|
||||
|
||||
err = ovl_set_opaque(opaquedir);
|
||||
if (err)
|
||||
goto out_cleanup;
|
||||
|
||||
mutex_lock(&opaquedir->d_inode->i_mutex);
|
||||
err = ovl_set_attr(opaquedir, &stat);
|
||||
mutex_unlock(&opaquedir->d_inode->i_mutex);
|
||||
if (err)
|
||||
goto out_cleanup;
|
||||
|
||||
err = ovl_do_rename(wdir, opaquedir, udir, upper, RENAME_EXCHANGE);
|
||||
if (err)
|
||||
goto out_cleanup;
|
||||
|
||||
ovl_cleanup_whiteouts(upper, list);
|
||||
ovl_cleanup(wdir, upper);
|
||||
unlock_rename(workdir, upperdir);
|
||||
|
||||
/* dentry's upper doesn't match now, get rid of it */
|
||||
d_drop(dentry);
|
||||
|
||||
return opaquedir;
|
||||
|
||||
out_cleanup:
|
||||
ovl_cleanup(wdir, opaquedir);
|
||||
out_dput:
|
||||
dput(opaquedir);
|
||||
out_unlock:
|
||||
unlock_rename(workdir, upperdir);
|
||||
out:
|
||||
return ERR_PTR(err);
|
||||
}
|
||||
|
||||
static struct dentry *ovl_check_empty_and_clear(struct dentry *dentry)
|
||||
{
|
||||
int err;
|
||||
struct dentry *ret = NULL;
|
||||
LIST_HEAD(list);
|
||||
|
||||
err = ovl_check_empty_dir(dentry, &list);
|
||||
if (err)
|
||||
ret = ERR_PTR(err);
|
||||
else {
|
||||
/*
|
||||
* If no upperdentry then skip clearing whiteouts.
|
||||
*
|
||||
* Can race with copy-up, since we don't hold the upperdir
|
||||
* mutex. Doesn't matter, since copy-up can't create a
|
||||
* non-empty directory from an empty one.
|
||||
*/
|
||||
if (ovl_dentry_upper(dentry))
|
||||
ret = ovl_clear_empty(dentry, &list);
|
||||
}
|
||||
|
||||
ovl_cache_free(&list);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
|
||||
struct kstat *stat, const char *link,
|
||||
struct dentry *hardlink)
|
||||
{
|
||||
struct dentry *workdir = ovl_workdir(dentry);
|
||||
struct inode *wdir = workdir->d_inode;
|
||||
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
|
||||
struct inode *udir = upperdir->d_inode;
|
||||
struct dentry *upper;
|
||||
struct dentry *newdentry;
|
||||
int err;
|
||||
|
||||
if (WARN_ON(!workdir))
|
||||
return -EROFS;
|
||||
|
||||
err = ovl_lock_rename_workdir(workdir, upperdir);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
newdentry = ovl_lookup_temp(workdir, dentry);
|
||||
err = PTR_ERR(newdentry);
|
||||
if (IS_ERR(newdentry))
|
||||
goto out_unlock;
|
||||
|
||||
upper = lookup_one_len(dentry->d_name.name, upperdir,
|
||||
dentry->d_name.len);
|
||||
err = PTR_ERR(upper);
|
||||
if (IS_ERR(upper))
|
||||
goto out_dput;
|
||||
|
||||
err = ovl_create_real(wdir, newdentry, stat, link, hardlink, true);
|
||||
if (err)
|
||||
goto out_dput2;
|
||||
|
||||
if (S_ISDIR(stat->mode)) {
|
||||
err = ovl_set_opaque(newdentry);
|
||||
if (err)
|
||||
goto out_cleanup;
|
||||
|
||||
err = ovl_do_rename(wdir, newdentry, udir, upper,
|
||||
RENAME_EXCHANGE);
|
||||
if (err)
|
||||
goto out_cleanup;
|
||||
|
||||
ovl_cleanup(wdir, upper);
|
||||
} else {
|
||||
err = ovl_do_rename(wdir, newdentry, udir, upper, 0);
|
||||
if (err)
|
||||
goto out_cleanup;
|
||||
}
|
||||
ovl_dentry_version_inc(dentry->d_parent);
|
||||
ovl_dentry_update(dentry, newdentry);
|
||||
ovl_copyattr(newdentry->d_inode, inode);
|
||||
d_instantiate(dentry, inode);
|
||||
newdentry = NULL;
|
||||
out_dput2:
|
||||
dput(upper);
|
||||
out_dput:
|
||||
dput(newdentry);
|
||||
out_unlock:
|
||||
unlock_rename(workdir, upperdir);
|
||||
out:
|
||||
return err;
|
||||
|
||||
out_cleanup:
|
||||
ovl_cleanup(wdir, newdentry);
|
||||
goto out_dput2;
|
||||
}
|
||||
|
||||
static int ovl_create_or_link(struct dentry *dentry, int mode, dev_t rdev,
|
||||
const char *link, struct dentry *hardlink)
|
||||
{
|
||||
int err;
|
||||
struct inode *inode;
|
||||
struct kstat stat = {
|
||||
.mode = mode,
|
||||
.rdev = rdev,
|
||||
};
|
||||
|
||||
err = -ENOMEM;
|
||||
inode = ovl_new_inode(dentry->d_sb, mode, dentry->d_fsdata);
|
||||
if (!inode)
|
||||
goto out;
|
||||
|
||||
err = ovl_copy_up(dentry->d_parent);
|
||||
if (err)
|
||||
goto out_iput;
|
||||
|
||||
if (!ovl_dentry_is_opaque(dentry)) {
|
||||
err = ovl_create_upper(dentry, inode, &stat, link, hardlink);
|
||||
} else {
|
||||
const struct cred *old_cred;
|
||||
struct cred *override_cred;
|
||||
|
||||
err = -ENOMEM;
|
||||
override_cred = prepare_creds();
|
||||
if (!override_cred)
|
||||
goto out_iput;
|
||||
|
||||
/*
|
||||
* CAP_SYS_ADMIN for setting opaque xattr
|
||||
* CAP_DAC_OVERRIDE for create in workdir, rename
|
||||
* CAP_FOWNER for removing whiteout from sticky dir
|
||||
*/
|
||||
cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN);
|
||||
cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
|
||||
cap_raise(override_cred->cap_effective, CAP_FOWNER);
|
||||
old_cred = override_creds(override_cred);
|
||||
|
||||
err = ovl_create_over_whiteout(dentry, inode, &stat, link,
|
||||
hardlink);
|
||||
|
||||
revert_creds(old_cred);
|
||||
put_cred(override_cred);
|
||||
}
|
||||
|
||||
if (!err)
|
||||
inode = NULL;
|
||||
out_iput:
|
||||
iput(inode);
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev,
|
||||
const char *link)
|
||||
{
|
||||
int err;
|
||||
|
||||
err = ovl_want_write(dentry);
|
||||
if (!err) {
|
||||
err = ovl_create_or_link(dentry, mode, rdev, link, NULL);
|
||||
ovl_drop_write(dentry);
|
||||
}
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
static int ovl_create(struct inode *dir, struct dentry *dentry, umode_t mode,
|
||||
bool excl)
|
||||
{
|
||||
return ovl_create_object(dentry, (mode & 07777) | S_IFREG, 0, NULL);
|
||||
}
|
||||
|
||||
static int ovl_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
|
||||
{
|
||||
return ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL);
|
||||
}
|
||||
|
||||
static int ovl_mknod(struct inode *dir, struct dentry *dentry, umode_t mode,
|
||||
dev_t rdev)
|
||||
{
|
||||
/* Don't allow creation of "whiteout" on overlay */
|
||||
if (S_ISCHR(mode) && rdev == WHITEOUT_DEV)
|
||||
return -EPERM;
|
||||
|
||||
return ovl_create_object(dentry, mode, rdev, NULL);
|
||||
}
|
||||
|
||||
static int ovl_symlink(struct inode *dir, struct dentry *dentry,
|
||||
const char *link)
|
||||
{
|
||||
return ovl_create_object(dentry, S_IFLNK, 0, link);
|
||||
}
|
||||
|
||||
static int ovl_link(struct dentry *old, struct inode *newdir,
|
||||
struct dentry *new)
|
||||
{
|
||||
int err;
|
||||
struct dentry *upper;
|
||||
|
||||
err = ovl_want_write(old);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
err = ovl_copy_up(old);
|
||||
if (err)
|
||||
goto out_drop_write;
|
||||
|
||||
upper = ovl_dentry_upper(old);
|
||||
err = ovl_create_or_link(new, upper->d_inode->i_mode, 0, NULL, upper);
|
||||
|
||||
out_drop_write:
|
||||
ovl_drop_write(old);
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir)
|
||||
{
|
||||
struct dentry *workdir = ovl_workdir(dentry);
|
||||
struct inode *wdir = workdir->d_inode;
|
||||
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
|
||||
struct inode *udir = upperdir->d_inode;
|
||||
struct dentry *whiteout;
|
||||
struct dentry *upper;
|
||||
struct dentry *opaquedir = NULL;
|
||||
int err;
|
||||
|
||||
if (WARN_ON(!workdir))
|
||||
return -EROFS;
|
||||
|
||||
if (is_dir) {
|
||||
if (OVL_TYPE_MERGE_OR_LOWER(ovl_path_type(dentry))) {
|
||||
opaquedir = ovl_check_empty_and_clear(dentry);
|
||||
err = PTR_ERR(opaquedir);
|
||||
if (IS_ERR(opaquedir))
|
||||
goto out;
|
||||
} else {
|
||||
LIST_HEAD(list);
|
||||
|
||||
/*
|
||||
* When removing an empty opaque directory, then it
|
||||
* makes no sense to replace it with an exact replica of
|
||||
* itself. But emptiness still needs to be checked.
|
||||
*/
|
||||
err = ovl_check_empty_dir(dentry, &list);
|
||||
ovl_cache_free(&list);
|
||||
if (err)
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
|
||||
err = ovl_lock_rename_workdir(workdir, upperdir);
|
||||
if (err)
|
||||
goto out_dput;
|
||||
|
||||
whiteout = ovl_whiteout(workdir, dentry);
|
||||
err = PTR_ERR(whiteout);
|
||||
if (IS_ERR(whiteout))
|
||||
goto out_unlock;
|
||||
|
||||
upper = ovl_dentry_upper(dentry);
|
||||
if (!upper) {
|
||||
upper = lookup_one_len(dentry->d_name.name, upperdir,
|
||||
dentry->d_name.len);
|
||||
err = PTR_ERR(upper);
|
||||
if (IS_ERR(upper))
|
||||
goto kill_whiteout;
|
||||
|
||||
err = ovl_do_rename(wdir, whiteout, udir, upper, 0);
|
||||
dput(upper);
|
||||
if (err)
|
||||
goto kill_whiteout;
|
||||
} else {
|
||||
int flags = 0;
|
||||
|
||||
if (opaquedir)
|
||||
upper = opaquedir;
|
||||
err = -ESTALE;
|
||||
if (upper->d_parent != upperdir)
|
||||
goto kill_whiteout;
|
||||
|
||||
if (is_dir)
|
||||
flags |= RENAME_EXCHANGE;
|
||||
|
||||
err = ovl_do_rename(wdir, whiteout, udir, upper, flags);
|
||||
if (err)
|
||||
goto kill_whiteout;
|
||||
|
||||
if (is_dir)
|
||||
ovl_cleanup(wdir, upper);
|
||||
}
|
||||
ovl_dentry_version_inc(dentry->d_parent);
|
||||
out_d_drop:
|
||||
d_drop(dentry);
|
||||
dput(whiteout);
|
||||
out_unlock:
|
||||
unlock_rename(workdir, upperdir);
|
||||
out_dput:
|
||||
dput(opaquedir);
|
||||
out:
|
||||
return err;
|
||||
|
||||
kill_whiteout:
|
||||
ovl_cleanup(wdir, whiteout);
|
||||
goto out_d_drop;
|
||||
}
|
||||
|
||||
static int ovl_remove_upper(struct dentry *dentry, bool is_dir)
|
||||
{
|
||||
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
|
||||
struct inode *dir = upperdir->d_inode;
|
||||
struct dentry *upper = ovl_dentry_upper(dentry);
|
||||
int err;
|
||||
|
||||
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
|
||||
err = -ESTALE;
|
||||
if (upper->d_parent == upperdir) {
|
||||
/* Don't let d_delete() think it can reset d_inode */
|
||||
dget(upper);
|
||||
if (is_dir)
|
||||
err = vfs_rmdir(dir, upper);
|
||||
else
|
||||
err = vfs_unlink(dir, upper, NULL);
|
||||
dput(upper);
|
||||
ovl_dentry_version_inc(dentry->d_parent);
|
||||
}
|
||||
|
||||
/*
|
||||
* Keeping this dentry hashed would mean having to release
|
||||
* upperpath/lowerpath, which could only be done if we are the
|
||||
* sole user of this dentry. Too tricky... Just unhash for
|
||||
* now.
|
||||
*/
|
||||
d_drop(dentry);
|
||||
mutex_unlock(&dir->i_mutex);
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
static inline int ovl_check_sticky(struct dentry *dentry)
|
||||
{
|
||||
struct inode *dir = ovl_dentry_real(dentry->d_parent)->d_inode;
|
||||
struct inode *inode = ovl_dentry_real(dentry)->d_inode;
|
||||
|
||||
if (check_sticky(dir, inode))
|
||||
return -EPERM;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ovl_do_remove(struct dentry *dentry, bool is_dir)
|
||||
{
|
||||
enum ovl_path_type type;
|
||||
int err;
|
||||
|
||||
err = ovl_check_sticky(dentry);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
err = ovl_want_write(dentry);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
err = ovl_copy_up(dentry->d_parent);
|
||||
if (err)
|
||||
goto out_drop_write;
|
||||
|
||||
type = ovl_path_type(dentry);
|
||||
if (OVL_TYPE_PURE_UPPER(type)) {
|
||||
err = ovl_remove_upper(dentry, is_dir);
|
||||
} else {
|
||||
const struct cred *old_cred;
|
||||
struct cred *override_cred;
|
||||
|
||||
err = -ENOMEM;
|
||||
override_cred = prepare_creds();
|
||||
if (!override_cred)
|
||||
goto out_drop_write;
|
||||
|
||||
/*
|
||||
* CAP_SYS_ADMIN for setting xattr on whiteout, opaque dir
|
||||
* CAP_DAC_OVERRIDE for create in workdir, rename
|
||||
* CAP_FOWNER for removing whiteout from sticky dir
|
||||
* CAP_FSETID for chmod of opaque dir
|
||||
* CAP_CHOWN for chown of opaque dir
|
||||
*/
|
||||
cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN);
|
||||
cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
|
||||
cap_raise(override_cred->cap_effective, CAP_FOWNER);
|
||||
cap_raise(override_cred->cap_effective, CAP_FSETID);
|
||||
cap_raise(override_cred->cap_effective, CAP_CHOWN);
|
||||
old_cred = override_creds(override_cred);
|
||||
|
||||
err = ovl_remove_and_whiteout(dentry, is_dir);
|
||||
|
||||
revert_creds(old_cred);
|
||||
put_cred(override_cred);
|
||||
}
|
||||
out_drop_write:
|
||||
ovl_drop_write(dentry);
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static int ovl_unlink(struct inode *dir, struct dentry *dentry)
|
||||
{
|
||||
return ovl_do_remove(dentry, false);
|
||||
}
|
||||
|
||||
static int ovl_rmdir(struct inode *dir, struct dentry *dentry)
|
||||
{
|
||||
return ovl_do_remove(dentry, true);
|
||||
}
|
||||
|
||||
static int ovl_rename2(struct inode *olddir, struct dentry *old,
|
||||
struct inode *newdir, struct dentry *new,
|
||||
unsigned int flags)
|
||||
{
|
||||
int err;
|
||||
enum ovl_path_type old_type;
|
||||
enum ovl_path_type new_type;
|
||||
struct dentry *old_upperdir;
|
||||
struct dentry *new_upperdir;
|
||||
struct dentry *olddentry;
|
||||
struct dentry *newdentry;
|
||||
struct dentry *trap;
|
||||
bool old_opaque;
|
||||
bool new_opaque;
|
||||
bool new_create = false;
|
||||
bool cleanup_whiteout = false;
|
||||
bool overwrite = !(flags & RENAME_EXCHANGE);
|
||||
bool is_dir = d_is_dir(old);
|
||||
bool new_is_dir = false;
|
||||
struct dentry *opaquedir = NULL;
|
||||
const struct cred *old_cred = NULL;
|
||||
struct cred *override_cred = NULL;
|
||||
|
||||
err = -EINVAL;
|
||||
if (flags & ~(RENAME_EXCHANGE | RENAME_NOREPLACE))
|
||||
goto out;
|
||||
|
||||
flags &= ~RENAME_NOREPLACE;
|
||||
|
||||
err = ovl_check_sticky(old);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
/* Don't copy up directory trees */
|
||||
old_type = ovl_path_type(old);
|
||||
err = -EXDEV;
|
||||
if (OVL_TYPE_MERGE_OR_LOWER(old_type) && is_dir)
|
||||
goto out;
|
||||
|
||||
if (new->d_inode) {
|
||||
err = ovl_check_sticky(new);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
if (d_is_dir(new))
|
||||
new_is_dir = true;
|
||||
|
||||
new_type = ovl_path_type(new);
|
||||
err = -EXDEV;
|
||||
if (!overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir)
|
||||
goto out;
|
||||
|
||||
err = 0;
|
||||
if (!OVL_TYPE_UPPER(new_type) && !OVL_TYPE_UPPER(old_type)) {
|
||||
if (ovl_dentry_lower(old)->d_inode ==
|
||||
ovl_dentry_lower(new)->d_inode)
|
||||
goto out;
|
||||
}
|
||||
if (OVL_TYPE_UPPER(new_type) && OVL_TYPE_UPPER(old_type)) {
|
||||
if (ovl_dentry_upper(old)->d_inode ==
|
||||
ovl_dentry_upper(new)->d_inode)
|
||||
goto out;
|
||||
}
|
||||
} else {
|
||||
if (ovl_dentry_is_opaque(new))
|
||||
new_type = __OVL_PATH_UPPER;
|
||||
else
|
||||
new_type = __OVL_PATH_UPPER | __OVL_PATH_PURE;
|
||||
}
|
||||
|
||||
err = ovl_want_write(old);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
err = ovl_copy_up(old);
|
||||
if (err)
|
||||
goto out_drop_write;
|
||||
|
||||
err = ovl_copy_up(new->d_parent);
|
||||
if (err)
|
||||
goto out_drop_write;
|
||||
if (!overwrite) {
|
||||
err = ovl_copy_up(new);
|
||||
if (err)
|
||||
goto out_drop_write;
|
||||
}
|
||||
|
||||
old_opaque = !OVL_TYPE_PURE_UPPER(old_type);
|
||||
new_opaque = !OVL_TYPE_PURE_UPPER(new_type);
|
||||
|
||||
if (old_opaque || new_opaque) {
|
||||
err = -ENOMEM;
|
||||
override_cred = prepare_creds();
|
||||
if (!override_cred)
|
||||
goto out_drop_write;
|
||||
|
||||
/*
|
||||
* CAP_SYS_ADMIN for setting xattr on whiteout, opaque dir
|
||||
* CAP_DAC_OVERRIDE for create in workdir
|
||||
* CAP_FOWNER for removing whiteout from sticky dir
|
||||
* CAP_FSETID for chmod of opaque dir
|
||||
* CAP_CHOWN for chown of opaque dir
|
||||
*/
|
||||
cap_raise(override_cred->cap_effective, CAP_SYS_ADMIN);
|
||||
cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
|
||||
cap_raise(override_cred->cap_effective, CAP_FOWNER);
|
||||
cap_raise(override_cred->cap_effective, CAP_FSETID);
|
||||
cap_raise(override_cred->cap_effective, CAP_CHOWN);
|
||||
old_cred = override_creds(override_cred);
|
||||
}
|
||||
|
||||
if (overwrite && OVL_TYPE_MERGE_OR_LOWER(new_type) && new_is_dir) {
|
||||
opaquedir = ovl_check_empty_and_clear(new);
|
||||
err = PTR_ERR(opaquedir);
|
||||
if (IS_ERR(opaquedir)) {
|
||||
opaquedir = NULL;
|
||||
goto out_revert_creds;
|
||||
}
|
||||
}
|
||||
|
||||
if (overwrite) {
|
||||
if (old_opaque) {
|
||||
if (new->d_inode || !new_opaque) {
|
||||
/* Whiteout source */
|
||||
flags |= RENAME_WHITEOUT;
|
||||
} else {
|
||||
/* Switch whiteouts */
|
||||
flags |= RENAME_EXCHANGE;
|
||||
}
|
||||
} else if (is_dir && !new->d_inode && new_opaque) {
|
||||
flags |= RENAME_EXCHANGE;
|
||||
cleanup_whiteout = true;
|
||||
}
|
||||
}
|
||||
|
||||
old_upperdir = ovl_dentry_upper(old->d_parent);
|
||||
new_upperdir = ovl_dentry_upper(new->d_parent);
|
||||
|
||||
trap = lock_rename(new_upperdir, old_upperdir);
|
||||
|
||||
olddentry = ovl_dentry_upper(old);
|
||||
newdentry = ovl_dentry_upper(new);
|
||||
if (newdentry) {
|
||||
if (opaquedir) {
|
||||
newdentry = opaquedir;
|
||||
opaquedir = NULL;
|
||||
} else {
|
||||
dget(newdentry);
|
||||
}
|
||||
} else {
|
||||
new_create = true;
|
||||
newdentry = lookup_one_len(new->d_name.name, new_upperdir,
|
||||
new->d_name.len);
|
||||
err = PTR_ERR(newdentry);
|
||||
if (IS_ERR(newdentry))
|
||||
goto out_unlock;
|
||||
}
|
||||
|
||||
err = -ESTALE;
|
||||
if (olddentry->d_parent != old_upperdir)
|
||||
goto out_dput;
|
||||
if (newdentry->d_parent != new_upperdir)
|
||||
goto out_dput;
|
||||
if (olddentry == trap)
|
||||
goto out_dput;
|
||||
if (newdentry == trap)
|
||||
goto out_dput;
|
||||
|
||||
if (is_dir && !old_opaque && new_opaque) {
|
||||
err = ovl_set_opaque(olddentry);
|
||||
if (err)
|
||||
goto out_dput;
|
||||
}
|
||||
if (!overwrite && new_is_dir && old_opaque && !new_opaque) {
|
||||
err = ovl_set_opaque(newdentry);
|
||||
if (err)
|
||||
goto out_dput;
|
||||
}
|
||||
|
||||
if (old_opaque || new_opaque) {
|
||||
err = ovl_do_rename(old_upperdir->d_inode, olddentry,
|
||||
new_upperdir->d_inode, newdentry,
|
||||
flags);
|
||||
} else {
|
||||
/* No debug for the plain case */
|
||||
BUG_ON(flags & ~RENAME_EXCHANGE);
|
||||
err = vfs_rename(old_upperdir->d_inode, olddentry,
|
||||
new_upperdir->d_inode, newdentry,
|
||||
NULL, flags);
|
||||
}
|
||||
|
||||
if (err) {
|
||||
if (is_dir && !old_opaque && new_opaque)
|
||||
ovl_remove_opaque(olddentry);
|
||||
if (!overwrite && new_is_dir && old_opaque && !new_opaque)
|
||||
ovl_remove_opaque(newdentry);
|
||||
goto out_dput;
|
||||
}
|
||||
|
||||
if (is_dir && old_opaque && !new_opaque)
|
||||
ovl_remove_opaque(olddentry);
|
||||
if (!overwrite && new_is_dir && !old_opaque && new_opaque)
|
||||
ovl_remove_opaque(newdentry);
|
||||
|
||||
if (old_opaque != new_opaque) {
|
||||
ovl_dentry_set_opaque(old, new_opaque);
|
||||
if (!overwrite)
|
||||
ovl_dentry_set_opaque(new, old_opaque);
|
||||
}
|
||||
|
||||
if (cleanup_whiteout)
|
||||
ovl_cleanup(old_upperdir->d_inode, newdentry);
|
||||
|
||||
ovl_dentry_version_inc(old->d_parent);
|
||||
ovl_dentry_version_inc(new->d_parent);
|
||||
|
||||
out_dput:
|
||||
dput(newdentry);
|
||||
out_unlock:
|
||||
unlock_rename(new_upperdir, old_upperdir);
|
||||
out_revert_creds:
|
||||
if (old_opaque || new_opaque) {
|
||||
revert_creds(old_cred);
|
||||
put_cred(override_cred);
|
||||
}
|
||||
out_drop_write:
|
||||
ovl_drop_write(old);
|
||||
out:
|
||||
dput(opaquedir);
|
||||
return err;
|
||||
}
|
||||
|
||||
const struct inode_operations ovl_dir_inode_operations = {
|
||||
.lookup = ovl_lookup,
|
||||
.mkdir = ovl_mkdir,
|
||||
.symlink = ovl_symlink,
|
||||
.unlink = ovl_unlink,
|
||||
.rmdir = ovl_rmdir,
|
||||
.rename2 = ovl_rename2,
|
||||
.link = ovl_link,
|
||||
.setattr = ovl_setattr,
|
||||
.create = ovl_create,
|
||||
.mknod = ovl_mknod,
|
||||
.permission = ovl_permission,
|
||||
.getattr = ovl_dir_getattr,
|
||||
.setxattr = ovl_setxattr,
|
||||
.getxattr = ovl_getxattr,
|
||||
.listxattr = ovl_listxattr,
|
||||
.removexattr = ovl_removexattr,
|
||||
};
|
||||
436
executer/kernel/mcoverlayfs/inode.c
Normal file
436
executer/kernel/mcoverlayfs/inode.c
Normal file
@ -0,0 +1,436 @@
|
||||
/*
|
||||
*
|
||||
* Copyright (C) 2011 Novell Inc.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify it
|
||||
* under the terms of the GNU General Public License version 2 as published by
|
||||
* the Free Software Foundation.
|
||||
*/
|
||||
|
||||
#include <linux/fs.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/xattr.h>
|
||||
#include "overlayfs.h"
|
||||
|
||||
static int ovl_copy_up_last(struct dentry *dentry, struct iattr *attr,
|
||||
bool no_data)
|
||||
{
|
||||
int err;
|
||||
struct dentry *parent;
|
||||
struct kstat stat;
|
||||
struct path lowerpath;
|
||||
|
||||
parent = dget_parent(dentry);
|
||||
err = ovl_copy_up(parent);
|
||||
if (err)
|
||||
goto out_dput_parent;
|
||||
|
||||
ovl_path_lower(dentry, &lowerpath);
|
||||
err = vfs_getattr(&lowerpath, &stat);
|
||||
if (err)
|
||||
goto out_dput_parent;
|
||||
|
||||
if (no_data)
|
||||
stat.size = 0;
|
||||
|
||||
err = ovl_copy_up_one(parent, dentry, &lowerpath, &stat, attr);
|
||||
|
||||
out_dput_parent:
|
||||
dput(parent);
|
||||
return err;
|
||||
}
|
||||
|
||||
int ovl_setattr(struct dentry *dentry, struct iattr *attr)
|
||||
{
|
||||
int err;
|
||||
struct dentry *upperdentry;
|
||||
|
||||
err = ovl_want_write(dentry);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
upperdentry = ovl_dentry_upper(dentry);
|
||||
if (upperdentry) {
|
||||
mutex_lock(&upperdentry->d_inode->i_mutex);
|
||||
err = notify_change(upperdentry, attr, NULL);
|
||||
mutex_unlock(&upperdentry->d_inode->i_mutex);
|
||||
} else {
|
||||
err = ovl_copy_up_last(dentry, attr, false);
|
||||
}
|
||||
ovl_drop_write(dentry);
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static int ovl_getattr(struct vfsmount *mnt, struct dentry *dentry,
|
||||
struct kstat *stat)
|
||||
{
|
||||
struct path realpath;
|
||||
|
||||
ovl_path_real(dentry, &realpath);
|
||||
return vfs_getattr(&realpath, stat);
|
||||
}
|
||||
|
||||
int ovl_permission(struct inode *inode, int mask)
|
||||
{
|
||||
struct ovl_entry *oe;
|
||||
struct dentry *alias = NULL;
|
||||
struct inode *realinode;
|
||||
struct dentry *realdentry;
|
||||
bool is_upper;
|
||||
int err;
|
||||
|
||||
if (S_ISDIR(inode->i_mode)) {
|
||||
oe = inode->i_private;
|
||||
} else if (mask & MAY_NOT_BLOCK) {
|
||||
return -ECHILD;
|
||||
} else {
|
||||
/*
|
||||
* For non-directories find an alias and get the info
|
||||
* from there.
|
||||
*/
|
||||
alias = d_find_any_alias(inode);
|
||||
if (WARN_ON(!alias))
|
||||
return -ENOENT;
|
||||
|
||||
oe = alias->d_fsdata;
|
||||
}
|
||||
|
||||
realdentry = ovl_entry_real(oe, &is_upper);
|
||||
|
||||
/* Careful in RCU walk mode */
|
||||
realinode = ACCESS_ONCE(realdentry->d_inode);
|
||||
if (!realinode) {
|
||||
WARN_ON(!(mask & MAY_NOT_BLOCK));
|
||||
err = -ENOENT;
|
||||
goto out_dput;
|
||||
}
|
||||
|
||||
if (mask & MAY_WRITE) {
|
||||
umode_t mode = realinode->i_mode;
|
||||
|
||||
/*
|
||||
* Writes will always be redirected to upper layer, so
|
||||
* ignore lower layer being read-only.
|
||||
*
|
||||
* If the overlay itself is read-only then proceed
|
||||
* with the permission check, don't return EROFS.
|
||||
* This will only happen if this is the lower layer of
|
||||
* another overlayfs.
|
||||
*
|
||||
* If upper fs becomes read-only after the overlay was
|
||||
* constructed return EROFS to prevent modification of
|
||||
* upper layer.
|
||||
*/
|
||||
err = -EROFS;
|
||||
if (is_upper && !IS_RDONLY(inode) && IS_RDONLY(realinode) &&
|
||||
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode)))
|
||||
goto out_dput;
|
||||
}
|
||||
|
||||
err = __inode_permission(realinode, mask);
|
||||
out_dput:
|
||||
dput(alias);
|
||||
return err;
|
||||
}
|
||||
|
||||
|
||||
struct ovl_link_data {
|
||||
struct dentry *realdentry;
|
||||
void *cookie;
|
||||
};
|
||||
|
||||
static void *ovl_follow_link(struct dentry *dentry, struct nameidata *nd)
|
||||
{
|
||||
void *ret;
|
||||
struct dentry *realdentry;
|
||||
struct inode *realinode;
|
||||
|
||||
realdentry = ovl_dentry_real(dentry);
|
||||
realinode = realdentry->d_inode;
|
||||
|
||||
if (WARN_ON(!realinode->i_op->follow_link))
|
||||
return ERR_PTR(-EPERM);
|
||||
|
||||
ret = realinode->i_op->follow_link(realdentry, nd);
|
||||
if (IS_ERR(ret))
|
||||
return ret;
|
||||
|
||||
if (realinode->i_op->put_link) {
|
||||
struct ovl_link_data *data;
|
||||
|
||||
data = kmalloc(sizeof(struct ovl_link_data), GFP_KERNEL);
|
||||
if (!data) {
|
||||
realinode->i_op->put_link(realdentry, nd, ret);
|
||||
return ERR_PTR(-ENOMEM);
|
||||
}
|
||||
data->realdentry = realdentry;
|
||||
data->cookie = ret;
|
||||
|
||||
return data;
|
||||
} else {
|
||||
return NULL;
|
||||
}
|
||||
}
|
||||
|
||||
static void ovl_put_link(struct dentry *dentry, struct nameidata *nd, void *c)
|
||||
{
|
||||
struct inode *realinode;
|
||||
struct ovl_link_data *data = c;
|
||||
|
||||
if (!data)
|
||||
return;
|
||||
|
||||
realinode = data->realdentry->d_inode;
|
||||
realinode->i_op->put_link(data->realdentry, nd, data->cookie);
|
||||
kfree(data);
|
||||
}
|
||||
|
||||
static int ovl_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
|
||||
{
|
||||
struct path realpath;
|
||||
struct inode *realinode;
|
||||
|
||||
ovl_path_real(dentry, &realpath);
|
||||
realinode = realpath.dentry->d_inode;
|
||||
|
||||
if (!realinode->i_op->readlink)
|
||||
return -EINVAL;
|
||||
|
||||
touch_atime(&realpath);
|
||||
|
||||
return realinode->i_op->readlink(realpath.dentry, buf, bufsiz);
|
||||
}
|
||||
|
||||
|
||||
static bool ovl_is_private_xattr(const char *name)
|
||||
{
|
||||
return strncmp(name, OVL_XATTR_PRE_NAME, OVL_XATTR_PRE_LEN) == 0;
|
||||
}
|
||||
|
||||
int ovl_setxattr(struct dentry *dentry, const char *name,
|
||||
const void *value, size_t size, int flags)
|
||||
{
|
||||
int err;
|
||||
struct dentry *upperdentry;
|
||||
|
||||
err = ovl_want_write(dentry);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
err = -EPERM;
|
||||
if (ovl_is_private_xattr(name))
|
||||
goto out_drop_write;
|
||||
|
||||
err = ovl_copy_up(dentry);
|
||||
if (err)
|
||||
goto out_drop_write;
|
||||
|
||||
upperdentry = ovl_dentry_upper(dentry);
|
||||
err = vfs_setxattr(upperdentry, name, value, size, flags);
|
||||
|
||||
out_drop_write:
|
||||
ovl_drop_write(dentry);
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static bool ovl_need_xattr_filter(struct dentry *dentry,
|
||||
enum ovl_path_type type)
|
||||
{
|
||||
if ((type & (__OVL_PATH_PURE | __OVL_PATH_UPPER)) == __OVL_PATH_UPPER)
|
||||
return S_ISDIR(dentry->d_inode->i_mode);
|
||||
else
|
||||
return false;
|
||||
}
|
||||
|
||||
ssize_t ovl_getxattr(struct dentry *dentry, const char *name,
|
||||
void *value, size_t size)
|
||||
{
|
||||
struct path realpath;
|
||||
enum ovl_path_type type = ovl_path_real(dentry, &realpath);
|
||||
|
||||
if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
|
||||
return -ENODATA;
|
||||
|
||||
return vfs_getxattr(realpath.dentry, name, value, size);
|
||||
}
|
||||
|
||||
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
|
||||
{
|
||||
struct path realpath;
|
||||
enum ovl_path_type type = ovl_path_real(dentry, &realpath);
|
||||
ssize_t res;
|
||||
int off;
|
||||
|
||||
res = vfs_listxattr(realpath.dentry, list, size);
|
||||
if (res <= 0 || size == 0)
|
||||
return res;
|
||||
|
||||
if (!ovl_need_xattr_filter(dentry, type))
|
||||
return res;
|
||||
|
||||
/* filter out private xattrs */
|
||||
for (off = 0; off < res;) {
|
||||
char *s = list + off;
|
||||
size_t slen = strlen(s) + 1;
|
||||
|
||||
BUG_ON(off + slen > res);
|
||||
|
||||
if (ovl_is_private_xattr(s)) {
|
||||
res -= slen;
|
||||
memmove(s, s + slen, res - off);
|
||||
} else {
|
||||
off += slen;
|
||||
}
|
||||
}
|
||||
|
||||
return res;
|
||||
}
|
||||
|
||||
int ovl_removexattr(struct dentry *dentry, const char *name)
|
||||
{
|
||||
int err;
|
||||
struct path realpath;
|
||||
enum ovl_path_type type = ovl_path_real(dentry, &realpath);
|
||||
|
||||
err = ovl_want_write(dentry);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
err = -ENODATA;
|
||||
if (ovl_need_xattr_filter(dentry, type) && ovl_is_private_xattr(name))
|
||||
goto out_drop_write;
|
||||
|
||||
if (!OVL_TYPE_UPPER(type)) {
|
||||
err = vfs_getxattr(realpath.dentry, name, NULL, 0);
|
||||
if (err < 0)
|
||||
goto out_drop_write;
|
||||
|
||||
err = ovl_copy_up(dentry);
|
||||
if (err)
|
||||
goto out_drop_write;
|
||||
|
||||
ovl_path_upper(dentry, &realpath);
|
||||
}
|
||||
|
||||
err = vfs_removexattr(realpath.dentry, name);
|
||||
out_drop_write:
|
||||
ovl_drop_write(dentry);
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static bool ovl_open_need_copy_up(int flags, enum ovl_path_type type,
|
||||
struct dentry *realdentry)
|
||||
{
|
||||
if (OVL_TYPE_UPPER(type))
|
||||
return false;
|
||||
|
||||
if (special_file(realdentry->d_inode->i_mode))
|
||||
return false;
|
||||
|
||||
if (!(OPEN_FMODE(flags) & FMODE_WRITE) && !(flags & O_TRUNC))
|
||||
return false;
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
static int ovl_dentry_open(struct dentry *dentry, struct file *file,
|
||||
const struct cred *cred)
|
||||
{
|
||||
int err;
|
||||
struct path realpath;
|
||||
enum ovl_path_type type;
|
||||
bool want_write = false;
|
||||
|
||||
type = ovl_path_real(dentry, &realpath);
|
||||
if (ovl_open_need_copy_up(file->f_flags, type, realpath.dentry)) {
|
||||
want_write = true;
|
||||
err = ovl_want_write(dentry);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
if (file->f_flags & O_TRUNC)
|
||||
err = ovl_copy_up_last(dentry, NULL, true);
|
||||
else
|
||||
err = ovl_copy_up(dentry);
|
||||
if (err)
|
||||
goto out_drop_write;
|
||||
|
||||
ovl_path_upper(dentry, &realpath);
|
||||
}
|
||||
|
||||
err = vfs_open(&realpath, file, cred);
|
||||
out_drop_write:
|
||||
if (want_write)
|
||||
ovl_drop_write(dentry);
|
||||
out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static const struct inode_operations ovl_file_inode_operations = {
|
||||
.setattr = ovl_setattr,
|
||||
.permission = ovl_permission,
|
||||
.getattr = ovl_getattr,
|
||||
.setxattr = ovl_setxattr,
|
||||
.getxattr = ovl_getxattr,
|
||||
.listxattr = ovl_listxattr,
|
||||
.removexattr = ovl_removexattr,
|
||||
.dentry_open = ovl_dentry_open,
|
||||
};
|
||||
|
||||
static const struct inode_operations ovl_symlink_inode_operations = {
|
||||
.setattr = ovl_setattr,
|
||||
.follow_link = ovl_follow_link,
|
||||
.put_link = ovl_put_link,
|
||||
.readlink = ovl_readlink,
|
||||
.getattr = ovl_getattr,
|
||||
.setxattr = ovl_setxattr,
|
||||
.getxattr = ovl_getxattr,
|
||||
.listxattr = ovl_listxattr,
|
||||
.removexattr = ovl_removexattr,
|
||||
};
|
||||
|
||||
struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
|
||||
struct ovl_entry *oe)
|
||||
{
|
||||
struct inode *inode;
|
||||
|
||||
inode = new_inode(sb);
|
||||
if (!inode)
|
||||
return NULL;
|
||||
|
||||
mode &= S_IFMT;
|
||||
|
||||
inode->i_ino = get_next_ino();
|
||||
inode->i_mode = mode;
|
||||
inode->i_flags |= S_NOATIME | S_NOCMTIME;
|
||||
|
||||
switch (mode) {
|
||||
case S_IFDIR:
|
||||
inode->i_private = oe;
|
||||
inode->i_op = &ovl_dir_inode_operations;
|
||||
inode->i_fop = &ovl_dir_operations;
|
||||
break;
|
||||
|
||||
case S_IFLNK:
|
||||
inode->i_op = &ovl_symlink_inode_operations;
|
||||
break;
|
||||
|
||||
case S_IFREG:
|
||||
case S_IFSOCK:
|
||||
case S_IFBLK:
|
||||
case S_IFCHR:
|
||||
case S_IFIFO:
|
||||
inode->i_op = &ovl_file_inode_operations;
|
||||
break;
|
||||
|
||||
default:
|
||||
WARN(1, "illegal file type: %i\n", mode);
|
||||
iput(inode);
|
||||
inode = NULL;
|
||||
}
|
||||
|
||||
return inode;
|
||||
}
|
||||
199
executer/kernel/mcoverlayfs/overlayfs.h
Normal file
199
executer/kernel/mcoverlayfs/overlayfs.h
Normal file
@ -0,0 +1,199 @@
|
||||
/*
|
||||
*
|
||||
* Copyright (C) 2011 Novell Inc.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify it
|
||||
* under the terms of the GNU General Public License version 2 as published by
|
||||
* the Free Software Foundation.
|
||||
*/
|
||||
|
||||
#include <linux/kernel.h>
|
||||
|
||||
struct ovl_entry;
|
||||
|
||||
enum ovl_path_type {
|
||||
__OVL_PATH_PURE = (1 << 0),
|
||||
__OVL_PATH_UPPER = (1 << 1),
|
||||
__OVL_PATH_MERGE = (1 << 2),
|
||||
};
|
||||
|
||||
#define OVL_TYPE_UPPER(type) ((type) & __OVL_PATH_UPPER)
|
||||
#define OVL_TYPE_MERGE(type) ((type) & __OVL_PATH_MERGE)
|
||||
#define OVL_TYPE_PURE_UPPER(type) ((type) & __OVL_PATH_PURE)
|
||||
#define OVL_TYPE_MERGE_OR_LOWER(type) \
|
||||
(OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type))
|
||||
|
||||
#define OVL_XATTR_PRE_NAME "trusted.overlay."
|
||||
#define OVL_XATTR_PRE_LEN 16
|
||||
#define OVL_XATTR_OPAQUE OVL_XATTR_PRE_NAME"opaque"
|
||||
|
||||
static inline int ovl_do_rmdir(struct inode *dir, struct dentry *dentry)
|
||||
{
|
||||
int err = vfs_rmdir(dir, dentry);
|
||||
pr_debug("rmdir(%pd2) = %i\n", dentry, err);
|
||||
return err;
|
||||
}
|
||||
|
||||
static inline int ovl_do_unlink(struct inode *dir, struct dentry *dentry)
|
||||
{
|
||||
int err = vfs_unlink(dir, dentry, NULL);
|
||||
pr_debug("unlink(%pd2) = %i\n", dentry, err);
|
||||
return err;
|
||||
}
|
||||
|
||||
static inline int ovl_do_link(struct dentry *old_dentry, struct inode *dir,
|
||||
struct dentry *new_dentry, bool debug)
|
||||
{
|
||||
int err = vfs_link(old_dentry, dir, new_dentry, NULL);
|
||||
if (debug) {
|
||||
pr_debug("link(%pd2, %pd2) = %i\n",
|
||||
old_dentry, new_dentry, err);
|
||||
}
|
||||
return err;
|
||||
}
|
||||
|
||||
static inline int ovl_do_create(struct inode *dir, struct dentry *dentry,
|
||||
umode_t mode, bool debug)
|
||||
{
|
||||
int err = vfs_create(dir, dentry, mode, true);
|
||||
if (debug)
|
||||
pr_debug("create(%pd2, 0%o) = %i\n", dentry, mode, err);
|
||||
return err;
|
||||
}
|
||||
|
||||
static inline int ovl_do_mkdir(struct inode *dir, struct dentry *dentry,
|
||||
umode_t mode, bool debug)
|
||||
{
|
||||
int err = vfs_mkdir(dir, dentry, mode);
|
||||
if (debug)
|
||||
pr_debug("mkdir(%pd2, 0%o) = %i\n", dentry, mode, err);
|
||||
return err;
|
||||
}
|
||||
|
||||
static inline int ovl_do_mknod(struct inode *dir, struct dentry *dentry,
|
||||
umode_t mode, dev_t dev, bool debug)
|
||||
{
|
||||
int err = vfs_mknod(dir, dentry, mode, dev);
|
||||
if (debug) {
|
||||
pr_debug("mknod(%pd2, 0%o, 0%o) = %i\n",
|
||||
dentry, mode, dev, err);
|
||||
}
|
||||
return err;
|
||||
}
|
||||
|
||||
static inline int ovl_do_symlink(struct inode *dir, struct dentry *dentry,
|
||||
const char *oldname, bool debug)
|
||||
{
|
||||
int err = vfs_symlink(dir, dentry, oldname);
|
||||
if (debug)
|
||||
pr_debug("symlink(\"%s\", %pd2) = %i\n", oldname, dentry, err);
|
||||
return err;
|
||||
}
|
||||
|
||||
static inline int ovl_do_setxattr(struct dentry *dentry, const char *name,
|
||||
const void *value, size_t size, int flags)
|
||||
{
|
||||
int err = vfs_setxattr(dentry, name, value, size, flags);
|
||||
pr_debug("setxattr(%pd2, \"%s\", \"%*s\", 0x%x) = %i\n",
|
||||
dentry, name, (int) size, (char *) value, flags, err);
|
||||
return err;
|
||||
}
|
||||
|
||||
static inline int ovl_do_removexattr(struct dentry *dentry, const char *name)
|
||||
{
|
||||
int err = vfs_removexattr(dentry, name);
|
||||
pr_debug("removexattr(%pd2, \"%s\") = %i\n", dentry, name, err);
|
||||
return err;
|
||||
}
|
||||
|
||||
static inline int ovl_do_rename(struct inode *olddir, struct dentry *olddentry,
|
||||
struct inode *newdir, struct dentry *newdentry,
|
||||
unsigned int flags)
|
||||
{
|
||||
int err;
|
||||
|
||||
pr_debug("rename2(%pd2, %pd2, 0x%x)\n",
|
||||
olddentry, newdentry, flags);
|
||||
|
||||
err = vfs_rename(olddir, olddentry, newdir, newdentry, NULL, flags);
|
||||
|
||||
if (err) {
|
||||
pr_debug("...rename2(%pd2, %pd2, ...) = %i\n",
|
||||
olddentry, newdentry, err);
|
||||
}
|
||||
return err;
|
||||
}
|
||||
|
||||
static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
|
||||
{
|
||||
int err = vfs_whiteout(dir, dentry);
|
||||
pr_debug("whiteout(%pd2) = %i\n", dentry, err);
|
||||
return err;
|
||||
}
|
||||
|
||||
enum ovl_path_type ovl_path_type(struct dentry *dentry);
|
||||
u64 ovl_dentry_version_get(struct dentry *dentry);
|
||||
void ovl_dentry_version_inc(struct dentry *dentry);
|
||||
void ovl_path_upper(struct dentry *dentry, struct path *path);
|
||||
void ovl_path_lower(struct dentry *dentry, struct path *path);
|
||||
enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
|
||||
int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
|
||||
struct dentry *ovl_dentry_upper(struct dentry *dentry);
|
||||
struct dentry *ovl_dentry_lower(struct dentry *dentry);
|
||||
struct dentry *ovl_dentry_real(struct dentry *dentry);
|
||||
struct dentry *ovl_entry_real(struct ovl_entry *oe, bool *is_upper);
|
||||
struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry);
|
||||
void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache);
|
||||
struct dentry *ovl_workdir(struct dentry *dentry);
|
||||
int ovl_want_write(struct dentry *dentry);
|
||||
void ovl_drop_write(struct dentry *dentry);
|
||||
bool ovl_dentry_is_opaque(struct dentry *dentry);
|
||||
void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque);
|
||||
bool ovl_is_whiteout(struct dentry *dentry);
|
||||
void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry);
|
||||
struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
|
||||
unsigned int flags);
|
||||
struct file *ovl_path_open(struct path *path, int flags);
|
||||
|
||||
struct dentry *ovl_upper_create(struct dentry *upperdir, struct dentry *dentry,
|
||||
struct kstat *stat, const char *link);
|
||||
|
||||
/* readdir.c */
|
||||
extern const struct file_operations ovl_dir_operations;
|
||||
int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list);
|
||||
void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list);
|
||||
void ovl_cache_free(struct list_head *list);
|
||||
|
||||
/* inode.c */
|
||||
int ovl_setattr(struct dentry *dentry, struct iattr *attr);
|
||||
int ovl_permission(struct inode *inode, int mask);
|
||||
int ovl_setxattr(struct dentry *dentry, const char *name,
|
||||
const void *value, size_t size, int flags);
|
||||
ssize_t ovl_getxattr(struct dentry *dentry, const char *name,
|
||||
void *value, size_t size);
|
||||
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size);
|
||||
int ovl_removexattr(struct dentry *dentry, const char *name);
|
||||
|
||||
struct inode *ovl_new_inode(struct super_block *sb, umode_t mode,
|
||||
struct ovl_entry *oe);
|
||||
static inline void ovl_copyattr(struct inode *from, struct inode *to)
|
||||
{
|
||||
to->i_uid = from->i_uid;
|
||||
to->i_gid = from->i_gid;
|
||||
}
|
||||
|
||||
/* dir.c */
|
||||
extern const struct inode_operations ovl_dir_inode_operations;
|
||||
struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry);
|
||||
int ovl_create_real(struct inode *dir, struct dentry *newdentry,
|
||||
struct kstat *stat, const char *link,
|
||||
struct dentry *hardlink, bool debug);
|
||||
void ovl_cleanup(struct inode *dir, struct dentry *dentry);
|
||||
|
||||
/* copy_up.c */
|
||||
int ovl_copy_up(struct dentry *dentry);
|
||||
int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
|
||||
struct path *lowerpath, struct kstat *stat,
|
||||
struct iattr *attr);
|
||||
int ovl_copy_xattr(struct dentry *old, struct dentry *new);
|
||||
int ovl_set_attr(struct dentry *upper, struct kstat *stat);
|
||||
557
executer/kernel/mcoverlayfs/readdir.c
Normal file
557
executer/kernel/mcoverlayfs/readdir.c
Normal file
@ -0,0 +1,557 @@
|
||||
/*
|
||||
*
|
||||
* Copyright (C) 2011 Novell Inc.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify it
|
||||
* under the terms of the GNU General Public License version 2 as published by
|
||||
* the Free Software Foundation.
|
||||
*/
|
||||
|
||||
#include <linux/fs.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/namei.h>
|
||||
#include <linux/file.h>
|
||||
#include <linux/xattr.h>
|
||||
#include <linux/rbtree.h>
|
||||
#include <linux/security.h>
|
||||
#include <linux/cred.h>
|
||||
#include "overlayfs.h"
|
||||
|
||||
struct ovl_cache_entry {
|
||||
unsigned int len;
|
||||
unsigned int type;
|
||||
u64 ino;
|
||||
struct list_head l_node;
|
||||
struct rb_node node;
|
||||
bool is_whiteout;
|
||||
char name[];
|
||||
};
|
||||
|
||||
struct ovl_dir_cache {
|
||||
long refcount;
|
||||
u64 version;
|
||||
struct list_head entries;
|
||||
};
|
||||
|
||||
struct ovl_readdir_data {
|
||||
struct dir_context ctx;
|
||||
bool is_merge;
|
||||
struct rb_root root;
|
||||
struct list_head *list;
|
||||
struct list_head middle;
|
||||
struct dentry *dir;
|
||||
int count;
|
||||
int err;
|
||||
};
|
||||
|
||||
struct ovl_dir_file {
|
||||
bool is_real;
|
||||
bool is_upper;
|
||||
struct ovl_dir_cache *cache;
|
||||
struct list_head *cursor;
|
||||
struct file *realfile;
|
||||
struct file *upperfile;
|
||||
};
|
||||
|
||||
static struct ovl_cache_entry *ovl_cache_entry_from_node(struct rb_node *n)
|
||||
{
|
||||
return container_of(n, struct ovl_cache_entry, node);
|
||||
}
|
||||
|
||||
static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root,
|
||||
const char *name, int len)
|
||||
{
|
||||
struct rb_node *node = root->rb_node;
|
||||
int cmp;
|
||||
|
||||
while (node) {
|
||||
struct ovl_cache_entry *p = ovl_cache_entry_from_node(node);
|
||||
|
||||
cmp = strncmp(name, p->name, len);
|
||||
if (cmp > 0)
|
||||
node = p->node.rb_right;
|
||||
else if (cmp < 0 || len < p->len)
|
||||
node = p->node.rb_left;
|
||||
else
|
||||
return p;
|
||||
}
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static struct ovl_cache_entry *ovl_cache_entry_new(struct dentry *dir,
|
||||
const char *name, int len,
|
||||
u64 ino, unsigned int d_type)
|
||||
{
|
||||
struct ovl_cache_entry *p;
|
||||
size_t size = offsetof(struct ovl_cache_entry, name[len + 1]);
|
||||
|
||||
p = kmalloc(size, GFP_KERNEL);
|
||||
if (!p)
|
||||
return NULL;
|
||||
|
||||
memcpy(p->name, name, len);
|
||||
p->name[len] = '\0';
|
||||
p->len = len;
|
||||
p->type = d_type;
|
||||
p->ino = ino;
|
||||
p->is_whiteout = false;
|
||||
|
||||
if (d_type == DT_CHR) {
|
||||
struct dentry *dentry;
|
||||
const struct cred *old_cred;
|
||||
struct cred *override_cred;
|
||||
|
||||
override_cred = prepare_creds();
|
||||
if (!override_cred) {
|
||||
kfree(p);
|
||||
return NULL;
|
||||
}
|
||||
|
||||
/*
|
||||
* CAP_DAC_OVERRIDE for lookup
|
||||
*/
|
||||
cap_raise(override_cred->cap_effective, CAP_DAC_OVERRIDE);
|
||||
old_cred = override_creds(override_cred);
|
||||
|
||||
dentry = lookup_one_len(name, dir, len);
|
||||
if (!IS_ERR(dentry)) {
|
||||
p->is_whiteout = ovl_is_whiteout(dentry);
|
||||
dput(dentry);
|
||||
}
|
||||
revert_creds(old_cred);
|
||||
put_cred(override_cred);
|
||||
}
|
||||
return p;
|
||||
}
|
||||
|
||||
static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
|
||||
const char *name, int len, u64 ino,
|
||||
unsigned int d_type)
|
||||
{
|
||||
struct rb_node **newp = &rdd->root.rb_node;
|
||||
struct rb_node *parent = NULL;
|
||||
struct ovl_cache_entry *p;
|
||||
|
||||
while (*newp) {
|
||||
int cmp;
|
||||
struct ovl_cache_entry *tmp;
|
||||
|
||||
parent = *newp;
|
||||
tmp = ovl_cache_entry_from_node(*newp);
|
||||
cmp = strncmp(name, tmp->name, len);
|
||||
if (cmp > 0)
|
||||
newp = &tmp->node.rb_right;
|
||||
else if (cmp < 0 || len < tmp->len)
|
||||
newp = &tmp->node.rb_left;
|
||||
else
|
||||
return 0;
|
||||
}
|
||||
|
||||
p = ovl_cache_entry_new(rdd->dir, name, len, ino, d_type);
|
||||
if (p == NULL)
|
||||
return -ENOMEM;
|
||||
|
||||
list_add_tail(&p->l_node, rdd->list);
|
||||
rb_link_node(&p->node, parent, newp);
|
||||
rb_insert_color(&p->node, &rdd->root);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ovl_fill_lower(struct ovl_readdir_data *rdd,
|
||||
const char *name, int namelen,
|
||||
loff_t offset, u64 ino, unsigned int d_type)
|
||||
{
|
||||
struct ovl_cache_entry *p;
|
||||
|
||||
p = ovl_cache_entry_find(&rdd->root, name, namelen);
|
||||
if (p) {
|
||||
list_move_tail(&p->l_node, &rdd->middle);
|
||||
} else {
|
||||
p = ovl_cache_entry_new(rdd->dir, name, namelen, ino, d_type);
|
||||
if (p == NULL)
|
||||
rdd->err = -ENOMEM;
|
||||
else
|
||||
list_add_tail(&p->l_node, &rdd->middle);
|
||||
}
|
||||
|
||||
return rdd->err;
|
||||
}
|
||||
|
||||
void ovl_cache_free(struct list_head *list)
|
||||
{
|
||||
struct ovl_cache_entry *p;
|
||||
struct ovl_cache_entry *n;
|
||||
|
||||
list_for_each_entry_safe(p, n, list, l_node)
|
||||
kfree(p);
|
||||
|
||||
INIT_LIST_HEAD(list);
|
||||
}
|
||||
|
||||
static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry)
|
||||
{
|
||||
struct ovl_dir_cache *cache = od->cache;
|
||||
|
||||
WARN_ON(cache->refcount <= 0);
|
||||
cache->refcount--;
|
||||
if (!cache->refcount) {
|
||||
if (ovl_dir_cache(dentry) == cache)
|
||||
ovl_set_dir_cache(dentry, NULL);
|
||||
|
||||
ovl_cache_free(&cache->entries);
|
||||
kfree(cache);
|
||||
}
|
||||
}
|
||||
|
||||
static int ovl_fill_merge(struct dir_context *ctx, const char *name,
|
||||
int namelen, loff_t offset, u64 ino,
|
||||
unsigned int d_type)
|
||||
{
|
||||
struct ovl_readdir_data *rdd =
|
||||
container_of(ctx, struct ovl_readdir_data, ctx);
|
||||
|
||||
rdd->count++;
|
||||
if (!rdd->is_merge)
|
||||
return ovl_cache_entry_add_rb(rdd, name, namelen, ino, d_type);
|
||||
else
|
||||
return ovl_fill_lower(rdd, name, namelen, offset, ino, d_type);
|
||||
}
|
||||
|
||||
static inline int ovl_dir_read(struct path *realpath,
|
||||
struct ovl_readdir_data *rdd)
|
||||
{
|
||||
struct file *realfile;
|
||||
int err;
|
||||
|
||||
realfile = ovl_path_open(realpath, O_RDONLY | O_DIRECTORY);
|
||||
if (IS_ERR(realfile))
|
||||
return PTR_ERR(realfile);
|
||||
|
||||
rdd->dir = realpath->dentry;
|
||||
rdd->ctx.pos = 0;
|
||||
do {
|
||||
rdd->count = 0;
|
||||
rdd->err = 0;
|
||||
err = iterate_dir(realfile, &rdd->ctx);
|
||||
if (err >= 0)
|
||||
err = rdd->err;
|
||||
} while (!err && rdd->count);
|
||||
fput(realfile);
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
static void ovl_dir_reset(struct file *file)
|
||||
{
|
||||
struct ovl_dir_file *od = file->private_data;
|
||||
struct ovl_dir_cache *cache = od->cache;
|
||||
struct dentry *dentry = file->f_path.dentry;
|
||||
enum ovl_path_type type = ovl_path_type(dentry);
|
||||
|
||||
if (cache && ovl_dentry_version_get(dentry) != cache->version) {
|
||||
ovl_cache_put(od, dentry);
|
||||
od->cache = NULL;
|
||||
od->cursor = NULL;
|
||||
}
|
||||
WARN_ON(!od->is_real && !OVL_TYPE_MERGE(type));
|
||||
if (od->is_real && OVL_TYPE_MERGE(type))
|
||||
od->is_real = false;
|
||||
}
|
||||
|
||||
static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list)
|
||||
{
|
||||
int err;
|
||||
struct path realpath;
|
||||
struct ovl_readdir_data rdd = {
|
||||
.ctx.actor = ovl_fill_merge,
|
||||
.list = list,
|
||||
.root = RB_ROOT,
|
||||
.is_merge = false,
|
||||
};
|
||||
int idx, next;
|
||||
|
||||
for (idx = 0; idx != -1; idx = next) {
|
||||
next = ovl_path_next(idx, dentry, &realpath);
|
||||
|
||||
if (next != -1) {
|
||||
err = ovl_dir_read(&realpath, &rdd);
|
||||
if (err)
|
||||
break;
|
||||
} else {
|
||||
/*
|
||||
* Insert lowest layer entries before upper ones, this
|
||||
* allows offsets to be reasonably constant
|
||||
*/
|
||||
list_add(&rdd.middle, rdd.list);
|
||||
rdd.is_merge = true;
|
||||
err = ovl_dir_read(&realpath, &rdd);
|
||||
list_del(&rdd.middle);
|
||||
}
|
||||
}
|
||||
return err;
|
||||
}
|
||||
|
||||
static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos)
|
||||
{
|
||||
struct list_head *p;
|
||||
loff_t off = 0;
|
||||
|
||||
list_for_each(p, &od->cache->entries) {
|
||||
if (off >= pos)
|
||||
break;
|
||||
off++;
|
||||
}
|
||||
/* Cursor is safe since the cache is stable */
|
||||
od->cursor = p;
|
||||
}
|
||||
|
||||
static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry)
|
||||
{
|
||||
int res;
|
||||
struct ovl_dir_cache *cache;
|
||||
|
||||
cache = ovl_dir_cache(dentry);
|
||||
if (cache && ovl_dentry_version_get(dentry) == cache->version) {
|
||||
cache->refcount++;
|
||||
return cache;
|
||||
}
|
||||
ovl_set_dir_cache(dentry, NULL);
|
||||
|
||||
cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL);
|
||||
if (!cache)
|
||||
return ERR_PTR(-ENOMEM);
|
||||
|
||||
cache->refcount = 1;
|
||||
INIT_LIST_HEAD(&cache->entries);
|
||||
|
||||
res = ovl_dir_read_merged(dentry, &cache->entries);
|
||||
if (res) {
|
||||
ovl_cache_free(&cache->entries);
|
||||
kfree(cache);
|
||||
return ERR_PTR(res);
|
||||
}
|
||||
|
||||
cache->version = ovl_dentry_version_get(dentry);
|
||||
ovl_set_dir_cache(dentry, cache);
|
||||
|
||||
return cache;
|
||||
}
|
||||
|
||||
static int ovl_iterate(struct file *file, struct dir_context *ctx)
|
||||
{
|
||||
struct ovl_dir_file *od = file->private_data;
|
||||
struct dentry *dentry = file->f_path.dentry;
|
||||
struct ovl_cache_entry *p;
|
||||
|
||||
if (!ctx->pos)
|
||||
ovl_dir_reset(file);
|
||||
|
||||
if (od->is_real)
|
||||
return iterate_dir(od->realfile, ctx);
|
||||
|
||||
if (!od->cache) {
|
||||
struct ovl_dir_cache *cache;
|
||||
|
||||
cache = ovl_cache_get(dentry);
|
||||
if (IS_ERR(cache))
|
||||
return PTR_ERR(cache);
|
||||
|
||||
od->cache = cache;
|
||||
ovl_seek_cursor(od, ctx->pos);
|
||||
}
|
||||
|
||||
while (od->cursor != &od->cache->entries) {
|
||||
p = list_entry(od->cursor, struct ovl_cache_entry, l_node);
|
||||
if (!p->is_whiteout)
|
||||
if (!dir_emit(ctx, p->name, p->len, p->ino, p->type))
|
||||
break;
|
||||
od->cursor = p->l_node.next;
|
||||
ctx->pos++;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
|
||||
static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin)
|
||||
{
|
||||
loff_t res;
|
||||
struct ovl_dir_file *od = file->private_data;
|
||||
|
||||
mutex_lock(&file_inode(file)->i_mutex);
|
||||
if (!file->f_pos)
|
||||
ovl_dir_reset(file);
|
||||
|
||||
if (od->is_real) {
|
||||
res = vfs_llseek(od->realfile, offset, origin);
|
||||
file->f_pos = od->realfile->f_pos;
|
||||
} else {
|
||||
res = -EINVAL;
|
||||
|
||||
switch (origin) {
|
||||
case SEEK_CUR:
|
||||
offset += file->f_pos;
|
||||
break;
|
||||
case SEEK_SET:
|
||||
break;
|
||||
default:
|
||||
goto out_unlock;
|
||||
}
|
||||
if (offset < 0)
|
||||
goto out_unlock;
|
||||
|
||||
if (offset != file->f_pos) {
|
||||
file->f_pos = offset;
|
||||
if (od->cache)
|
||||
ovl_seek_cursor(od, offset);
|
||||
}
|
||||
res = offset;
|
||||
}
|
||||
out_unlock:
|
||||
mutex_unlock(&file_inode(file)->i_mutex);
|
||||
|
||||
return res;
|
||||
}
|
||||
|
||||
static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
|
||||
int datasync)
|
||||
{
|
||||
struct ovl_dir_file *od = file->private_data;
|
||||
struct dentry *dentry = file->f_path.dentry;
|
||||
struct file *realfile = od->realfile;
|
||||
|
||||
/*
|
||||
* Need to check if we started out being a lower dir, but got copied up
|
||||
*/
|
||||
if (!od->is_upper && OVL_TYPE_UPPER(ovl_path_type(dentry))) {
|
||||
struct inode *inode = file_inode(file);
|
||||
|
||||
realfile = lockless_dereference(od->upperfile);
|
||||
if (!realfile) {
|
||||
struct path upperpath;
|
||||
|
||||
ovl_path_upper(dentry, &upperpath);
|
||||
realfile = ovl_path_open(&upperpath, O_RDONLY);
|
||||
smp_mb__before_spinlock();
|
||||
mutex_lock(&inode->i_mutex);
|
||||
if (!od->upperfile) {
|
||||
if (IS_ERR(realfile)) {
|
||||
mutex_unlock(&inode->i_mutex);
|
||||
return PTR_ERR(realfile);
|
||||
}
|
||||
od->upperfile = realfile;
|
||||
} else {
|
||||
/* somebody has beaten us to it */
|
||||
if (!IS_ERR(realfile))
|
||||
fput(realfile);
|
||||
realfile = od->upperfile;
|
||||
}
|
||||
mutex_unlock(&inode->i_mutex);
|
||||
}
|
||||
}
|
||||
|
||||
return vfs_fsync_range(realfile, start, end, datasync);
|
||||
}
|
||||
|
||||
static int ovl_dir_release(struct inode *inode, struct file *file)
|
||||
{
|
||||
struct ovl_dir_file *od = file->private_data;
|
||||
|
||||
if (od->cache) {
|
||||
mutex_lock(&inode->i_mutex);
|
||||
ovl_cache_put(od, file->f_path.dentry);
|
||||
mutex_unlock(&inode->i_mutex);
|
||||
}
|
||||
fput(od->realfile);
|
||||
if (od->upperfile)
|
||||
fput(od->upperfile);
|
||||
kfree(od);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int ovl_dir_open(struct inode *inode, struct file *file)
|
||||
{
|
||||
struct path realpath;
|
||||
struct file *realfile;
|
||||
struct ovl_dir_file *od;
|
||||
enum ovl_path_type type;
|
||||
|
||||
od = kzalloc(sizeof(struct ovl_dir_file), GFP_KERNEL);
|
||||
if (!od)
|
||||
return -ENOMEM;
|
||||
|
||||
type = ovl_path_real(file->f_path.dentry, &realpath);
|
||||
realfile = ovl_path_open(&realpath, file->f_flags);
|
||||
if (IS_ERR(realfile)) {
|
||||
kfree(od);
|
||||
return PTR_ERR(realfile);
|
||||
}
|
||||
od->realfile = realfile;
|
||||
od->is_real = !OVL_TYPE_MERGE(type);
|
||||
od->is_upper = OVL_TYPE_UPPER(type);
|
||||
file->private_data = od;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
const struct file_operations ovl_dir_operations = {
|
||||
.read = generic_read_dir,
|
||||
.open = ovl_dir_open,
|
||||
.iterate = ovl_iterate,
|
||||
.llseek = ovl_dir_llseek,
|
||||
.fsync = ovl_dir_fsync,
|
||||
.release = ovl_dir_release,
|
||||
};
|
||||
|
||||
int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)
|
||||
{
|
||||
int err;
|
||||
struct ovl_cache_entry *p;
|
||||
|
||||
err = ovl_dir_read_merged(dentry, list);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
err = 0;
|
||||
|
||||
list_for_each_entry(p, list, l_node) {
|
||||
if (p->is_whiteout)
|
||||
continue;
|
||||
|
||||
if (p->name[0] == '.') {
|
||||
if (p->len == 1)
|
||||
continue;
|
||||
if (p->len == 2 && p->name[1] == '.')
|
||||
continue;
|
||||
}
|
||||
err = -ENOTEMPTY;
|
||||
break;
|
||||
}
|
||||
|
||||
return err;
|
||||
}
|
||||
|
||||
void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list)
|
||||
{
|
||||
struct ovl_cache_entry *p;
|
||||
|
||||
mutex_lock_nested(&upper->d_inode->i_mutex, I_MUTEX_CHILD);
|
||||
list_for_each_entry(p, list, l_node) {
|
||||
struct dentry *dentry;
|
||||
|
||||
if (!p->is_whiteout)
|
||||
continue;
|
||||
|
||||
dentry = lookup_one_len(p->name, upper, p->len);
|
||||
if (IS_ERR(dentry)) {
|
||||
pr_err("overlayfs: lookup '%s/%.*s' failed (%i)\n",
|
||||
upper->d_name.name, p->len, p->name,
|
||||
(int) PTR_ERR(dentry));
|
||||
continue;
|
||||
}
|
||||
ovl_cleanup(upper->d_inode, dentry);
|
||||
dput(dentry);
|
||||
}
|
||||
mutex_unlock(&upper->d_inode->i_mutex);
|
||||
}
|
||||
1046
executer/kernel/mcoverlayfs/super.c
Normal file
1046
executer/kernel/mcoverlayfs/super.c
Normal file
File diff suppressed because it is too large
Load Diff
Reference in New Issue
Block a user