diff options
| -rw-r--r-- | fs/char_dev.c | 3 | ||||
| -rw-r--r-- | fs/namei.c | 21 | ||||
| -rw-r--r-- | include/linux/device_cgroup.h | 3 | ||||
| -rw-r--r-- | include/linux/fs.h | 6 |
4 files changed, 14 insertions, 19 deletions
diff --git a/fs/char_dev.c b/fs/char_dev.c index c5e6eff5a381..ba0ded7842a7 100644 --- a/fs/char_dev.c +++ b/fs/char_dev.c @@ -483,6 +483,9 @@ int cdev_add(struct cdev *p, dev_t dev, unsigned count) p->dev = dev; p->count = count; + if (WARN_ON(dev == WHITEOUT_DEV)) + return -EBUSY; + error = kobj_map(cdev_map, dev, count, NULL, exact_match, exact_lock, p); if (error) diff --git a/fs/namei.c b/fs/namei.c index a320371899cf..d81f73ff1a8b 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3505,12 +3505,14 @@ EXPORT_SYMBOL(user_path_create); int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) { + bool is_whiteout = S_ISCHR(mode) && dev == WHITEOUT_DEV; int error = may_create(dir, dentry); if (error) return error; - if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD)) + if ((S_ISCHR(mode) || S_ISBLK(mode)) && !is_whiteout && + !capable(CAP_MKNOD)) return -EPERM; if (!dir->i_op->mknod) @@ -4345,9 +4347,6 @@ static int do_renameat2(int olddfd, const char __user *oldname, int newdfd, (flags & RENAME_EXCHANGE)) return -EINVAL; - if ((flags & RENAME_WHITEOUT) && !capable(CAP_MKNOD)) - return -EPERM; - if (flags & RENAME_EXCHANGE) target_flags = 0; @@ -4483,20 +4482,6 @@ SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newna return do_renameat2(AT_FDCWD, oldname, AT_FDCWD, newname, 0); } -int vfs_whiteout(struct inode *dir, struct dentry *dentry) -{ - int error = may_create(dir, dentry); - if (error) - return error; - - if (!dir->i_op->mknod) - return -EPERM; - - return dir->i_op->mknod(dir, dentry, - S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV); -} -EXPORT_SYMBOL(vfs_whiteout); - int readlink_copy(char __user *buffer, int buflen, const char *link) { int len = PTR_ERR(link); diff --git a/include/linux/device_cgroup.h b/include/linux/device_cgroup.h index fa35b52e0002..57e63bd63370 100644 --- a/include/linux/device_cgroup.h +++ b/include/linux/device_cgroup.h @@ -51,6 +51,9 @@ static inline int devcgroup_inode_mknod(int mode, dev_t dev) if (!S_ISBLK(mode) && !S_ISCHR(mode)) return 0; + if (S_ISCHR(mode) && dev == WHITEOUT_DEV) + return 0; + if (S_ISBLK(mode)) type = DEVCG_DEV_BLOCK; else diff --git a/include/linux/fs.h b/include/linux/fs.h index 4f6f59b4f22a..15665ef1ef90 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1721,7 +1721,11 @@ extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct ino extern int vfs_rmdir(struct inode *, struct dentry *); extern int vfs_unlink(struct inode *, struct dentry *, struct inode **); extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int); -extern int vfs_whiteout(struct inode *, struct dentry *); + +static inline int vfs_whiteout(struct inode *dir, struct dentry *dentry) +{ + return vfs_mknod(dir, dentry, S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV); +} extern struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, int open_flag); |