forked from luck/tmp_suning_uos_patched
93f210dd9e
Port commit a090d9132c into ext2:
All modifications of ->i_flags in inodes that might be visible to somebody
else must be under ->i_mutex. That patch fixes ext2 ioctl() setting S_APPEND.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
119 lines
2.7 KiB
C
119 lines
2.7 KiB
C
/*
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* linux/fs/ext2/ioctl.c
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*
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* Copyright (C) 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*/
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#include "ext2.h"
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#include <linux/capability.h>
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#include <linux/time.h>
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#include <linux/sched.h>
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#include <linux/compat.h>
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#include <linux/smp_lock.h>
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#include <asm/current.h>
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#include <asm/uaccess.h>
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int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
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unsigned long arg)
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{
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struct ext2_inode_info *ei = EXT2_I(inode);
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unsigned int flags;
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ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
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switch (cmd) {
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case EXT2_IOC_GETFLAGS:
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flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
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return put_user(flags, (int __user *) arg);
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case EXT2_IOC_SETFLAGS: {
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unsigned int oldflags;
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if (IS_RDONLY(inode))
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return -EROFS;
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if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
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return -EACCES;
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if (get_user(flags, (int __user *) arg))
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return -EFAULT;
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if (!S_ISDIR(inode->i_mode))
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flags &= ~EXT2_DIRSYNC_FL;
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mutex_lock(&inode->i_mutex);
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oldflags = ei->i_flags;
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/*
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* The IMMUTABLE and APPEND_ONLY flags can only be changed by
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* the relevant capability.
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*
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* This test looks nicer. Thanks to Pauline Middelink
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*/
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if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
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if (!capable(CAP_LINUX_IMMUTABLE)) {
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mutex_unlock(&inode->i_mutex);
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return -EPERM;
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}
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}
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flags = flags & EXT2_FL_USER_MODIFIABLE;
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flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
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ei->i_flags = flags;
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mutex_unlock(&inode->i_mutex);
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ext2_set_inode_flags(inode);
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inode->i_ctime = CURRENT_TIME_SEC;
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mark_inode_dirty(inode);
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return 0;
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}
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case EXT2_IOC_GETVERSION:
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return put_user(inode->i_generation, (int __user *) arg);
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case EXT2_IOC_SETVERSION:
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if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
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return -EPERM;
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if (IS_RDONLY(inode))
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return -EROFS;
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if (get_user(inode->i_generation, (int __user *) arg))
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return -EFAULT;
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inode->i_ctime = CURRENT_TIME_SEC;
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mark_inode_dirty(inode);
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return 0;
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default:
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return -ENOTTY;
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}
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}
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#ifdef CONFIG_COMPAT
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long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
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{
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struct inode *inode = file->f_dentry->d_inode;
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int ret;
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/* These are just misnamed, they actually get/put from/to user an int */
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switch (cmd) {
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case EXT2_IOC32_GETFLAGS:
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cmd = EXT2_IOC_GETFLAGS;
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break;
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case EXT2_IOC32_SETFLAGS:
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cmd = EXT2_IOC_SETFLAGS;
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break;
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case EXT2_IOC32_GETVERSION:
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cmd = EXT2_IOC_GETVERSION;
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break;
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case EXT2_IOC32_SETVERSION:
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cmd = EXT2_IOC_SETVERSION;
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break;
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default:
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return -ENOIOCTLCMD;
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}
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lock_kernel();
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ret = ext2_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
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unlock_kernel();
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return ret;
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}
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#endif
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