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efivars: convert to fileattr 

Use the fileattr API to let the VFS handle locking, permission checking and
conversion.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
This commit is contained in:
Miklos Szeredi 2021-04-07 14:36:44 +02:00
parent 9fefd5db08
commit d701ea284c
2 changed files with 44 additions and 77 deletions
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77
fs/efivarfs/file.c
View File

@ -106,86 +106,9 @@ out_free:
return size;
}
static inline unsigned int efivarfs_getflags(struct inode *inode)
{
unsigned int i_flags;
unsigned int flags = 0;
i_flags = inode->i_flags;
if (i_flags & S_IMMUTABLE)
flags |= FS_IMMUTABLE_FL;
return flags;
}
static int
efivarfs_ioc_getxflags(struct file *file, void __user *arg)
{
struct inode *inode = file->f_mapping->host;
unsigned int flags = efivarfs_getflags(inode);
if (copy_to_user(arg, &flags, sizeof(flags)))
return -EFAULT;
return 0;
}
static int
efivarfs_ioc_setxflags(struct file *file, void __user *arg)
{
struct inode *inode = file->f_mapping->host;
unsigned int flags;
unsigned int i_flags = 0;
unsigned int oldflags = efivarfs_getflags(inode);
int error;
if (!inode_owner_or_capable(&init_user_ns, inode))
return -EACCES;
if (copy_from_user(&flags, arg, sizeof(flags)))
return -EFAULT;
if (flags & ~FS_IMMUTABLE_FL)
return -EOPNOTSUPP;
if (flags & FS_IMMUTABLE_FL)
i_flags |= S_IMMUTABLE;
error = mnt_want_write_file(file);
if (error)
return error;
inode_lock(inode);
error = vfs_ioc_setflags_prepare(inode, oldflags, flags);
if (error)
goto out;
inode_set_flags(inode, i_flags, S_IMMUTABLE);
out:
inode_unlock(inode);
mnt_drop_write_file(file);
return error;
}
static long
efivarfs_file_ioctl(struct file *file, unsigned int cmd, unsigned long p)
{
void __user *arg = (void __user *)p;
switch (cmd) {
case FS_IOC_GETFLAGS:
return efivarfs_ioc_getxflags(file, arg);
case FS_IOC_SETFLAGS:
return efivarfs_ioc_setxflags(file, arg);
}
return -ENOTTY;
}
const struct file_operations efivarfs_file_operations = {
.open = simple_open,
.read = efivarfs_file_read,
.write = efivarfs_file_write,
.llseek = no_llseek,
.unlocked_ioctl = efivarfs_file_ioctl,
};

44
fs/efivarfs/inode.c
View File

@ -10,9 +10,12 @@
#include <linux/kmemleak.h>
#include <linux/slab.h>
#include <linux/uuid.h>
#include <linux/fileattr.h>
#include "internal.h"
static const struct inode_operations efivarfs_file_inode_operations;
struct inode *efivarfs_get_inode(struct super_block *sb,
const struct inode *dir, int mode,
dev_t dev, bool is_removable)
@ -26,6 +29,7 @@ struct inode *efivarfs_get_inode(struct super_block *sb,
inode->i_flags = is_removable ? 0 : S_IMMUTABLE;
switch (mode & S_IFMT) {
case S_IFREG:
inode->i_op = &efivarfs_file_inode_operations;
inode->i_fop = &efivarfs_file_operations;
break;
case S_IFDIR:
@ -138,3 +142,43 @@ const struct inode_operations efivarfs_dir_inode_operations = {
.unlink = efivarfs_unlink,
.create = efivarfs_create,
};
static int
efivarfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
{
unsigned int i_flags;
unsigned int flags = 0;
i_flags = d_inode(dentry)->i_flags;
if (i_flags & S_IMMUTABLE)
flags |= FS_IMMUTABLE_FL;
fileattr_fill_flags(fa, flags);
return 0;
}
static int
efivarfs_fileattr_set(struct user_namespace *mnt_userns,
struct dentry *dentry, struct fileattr *fa)
{
unsigned int i_flags = 0;
if (fileattr_has_fsx(fa))
return -EOPNOTSUPP;
if (fa->flags & ~FS_IMMUTABLE_FL)
return -EOPNOTSUPP;
if (fa->flags & FS_IMMUTABLE_FL)
i_flags |= S_IMMUTABLE;
inode_set_flags(d_inode(dentry), i_flags, S_IMMUTABLE);
return 0;
}
static const struct inode_operations efivarfs_file_inode_operations = {
.fileattr_get = efivarfs_fileattr_get,
.fileattr_set = efivarfs_fileattr_set,
};