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Merge branch 'work.gfs2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

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Pull gfs2 setattr updates from Al Viro:
 "Make it possible for filesystems to use a generic 'may_setattr()' and
  switch gfs2 to using it"

* 'work.gfs2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  gfs2: Switch to may_setattr in gfs2_setattr
  fs: Move notify_change permission checks into may_setattr
This commit is contained in:
Linus Torvalds 2021-09-09 12:45:26 -07:00
commit 7b871c7713
3 changed files with 35 additions and 21 deletions
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50
fs/attr.c
View File

@ -249,6 +249,34 @@ void setattr_copy(struct user_namespace *mnt_userns, struct inode *inode,
}
EXPORT_SYMBOL(setattr_copy);
int may_setattr(struct user_namespace *mnt_userns, struct inode *inode,
unsigned int ia_valid)
{
int error;
if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_TIMES_SET)) {
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
return -EPERM;
}
/*
* If utimes(2) and friends are called with times == NULL (or both
* times are UTIME_NOW), then we need to check for write permission
*/
if (ia_valid & ATTR_TOUCH) {
if (IS_IMMUTABLE(inode))
return -EPERM;
if (!inode_owner_or_capable(mnt_userns, inode)) {
error = inode_permission(mnt_userns, inode, MAY_WRITE);
if (error)
return error;
}
}
return 0;
}
EXPORT_SYMBOL(may_setattr);
/**
* notify_change - modify attributes of a filesytem object
* @mnt_userns: user namespace of the mount the inode was found from
@ -290,25 +318,9 @@ int notify_change(struct user_namespace *mnt_userns, struct dentry *dentry,
WARN_ON_ONCE(!inode_is_locked(inode));
if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_TIMES_SET)) {
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
return -EPERM;
}
/*
* If utimes(2) and friends are called with times == NULL (or both
* times are UTIME_NOW), then we need to check for write permission
*/
if (ia_valid & ATTR_TOUCH) {
if (IS_IMMUTABLE(inode))
return -EPERM;
if (!inode_owner_or_capable(mnt_userns, inode)) {
error = inode_permission(mnt_userns, inode, MAY_WRITE);
if (error)
return error;
}
}
error = may_setattr(mnt_userns, inode, ia_valid);
if (error)
return error;
if ((ia_valid & ATTR_MODE)) {
umode_t amode = attr->ia_mode;

4
fs/gfs2/inode.c
View File

@ -1985,8 +1985,8 @@ static int gfs2_setattr(struct user_namespace *mnt_userns,
if (error)
goto out;
error = -EPERM;
if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
error = may_setattr(&init_user_ns, inode, attr->ia_valid);
if (error)
goto error;
error = setattr_prepare(&init_user_ns, dentry, attr);

2
include/linux/fs.h
View File

@ -3439,6 +3439,8 @@ extern int buffer_migrate_page_norefs(struct address_space *,
#define buffer_migrate_page_norefs NULL
#endif
int may_setattr(struct user_namespace *mnt_userns, struct inode *inode,
unsigned int ia_valid);
int setattr_prepare(struct user_namespace *, struct dentry *, struct iattr *);
extern int inode_newsize_ok(const struct inode *, loff_t offset);
void setattr_copy(struct user_namespace *, struct inode *inode,