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path: root/fs/efivarfs/super.c
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Diffstat (limited to 'fs/efivarfs/super.c')
-rw-r--r--fs/efivarfs/super.c122
1 files changed, 107 insertions, 15 deletions
diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index 586c5709dfb5..11ebddc57bc7 100644
--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -8,29 +8,64 @@
#include <linux/efi.h>
#include <linux/fs.h>
#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/ucs2_string.h>
#include <linux/slab.h>
#include <linux/magic.h>
#include <linux/statfs.h>
+#include <linux/notifier.h>
#include <linux/printk.h>
#include "internal.h"
-LIST_HEAD(efivarfs_list);
+static int efivarfs_ops_notifier(struct notifier_block *nb, unsigned long event,
+ void *data)
+{
+ struct efivarfs_fs_info *sfi = container_of(nb, struct efivarfs_fs_info, nb);
+
+ switch (event) {
+ case EFIVAR_OPS_RDONLY:
+ sfi->sb->s_flags |= SB_RDONLY;
+ break;
+ case EFIVAR_OPS_RDWR:
+ sfi->sb->s_flags &= ~SB_RDONLY;
+ break;
+ default:
+ return NOTIFY_DONE;
+ }
+
+ return NOTIFY_OK;
+}
static void efivarfs_evict_inode(struct inode *inode)
{
clear_inode(inode);
}
+static int efivarfs_show_options(struct seq_file *m, struct dentry *root)
+{
+ struct super_block *sb = root->d_sb;
+ struct efivarfs_fs_info *sbi = sb->s_fs_info;
+ struct efivarfs_mount_opts *opts = &sbi->mount_opts;
+
+ if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
+ seq_printf(m, ",uid=%u",
+ from_kuid_munged(&init_user_ns, opts->uid));
+ if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
+ seq_printf(m, ",gid=%u",
+ from_kgid_munged(&init_user_ns, opts->gid));
+ return 0;
+}
+
static int efivarfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
const u32 attr = EFI_VARIABLE_NON_VOLATILE |
EFI_VARIABLE_BOOTSERVICE_ACCESS |
EFI_VARIABLE_RUNTIME_ACCESS;
u64 storage_space, remaining_space, max_variable_size;
+ u64 id = huge_encode_dev(dentry->d_sb->s_dev);
efi_status_t status;
/* Some UEFI firmware does not implement QueryVariableInfo() */
@@ -54,6 +89,7 @@ static int efivarfs_statfs(struct dentry *dentry, struct kstatfs *buf)
buf->f_blocks = storage_space;
buf->f_bfree = remaining_space;
buf->f_type = dentry->d_sb->s_magic;
+ buf->f_fsid = u64_to_fsid(id);
/*
* In f_bavail we declare the free space that the kernel will allow writing
@@ -71,6 +107,7 @@ static const struct super_operations efivarfs_ops = {
.statfs = efivarfs_statfs,
.drop_inode = generic_delete_inode,
.evict_inode = efivarfs_evict_inode,
+ .show_options = efivarfs_show_options,
};
/*
@@ -145,7 +182,8 @@ static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name)
}
static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
- unsigned long name_size, void *data)
+ unsigned long name_size, void *data,
+ struct list_head *list)
{
struct super_block *sb = (struct super_block *)data;
struct efivar_entry *entry;
@@ -200,7 +238,7 @@ static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
}
__efivar_entry_get(entry, NULL, &size, NULL);
- __efivar_entry_add(entry, &efivarfs_list);
+ __efivar_entry_add(entry, list);
/* copied by the above to local storage in the dentry. */
kfree(name);
@@ -229,15 +267,48 @@ static int efivarfs_destroy(struct efivar_entry *entry, void *data)
return 0;
}
+enum {
+ Opt_uid, Opt_gid,
+};
+
+static const struct fs_parameter_spec efivarfs_parameters[] = {
+ fsparam_uid("uid", Opt_uid),
+ fsparam_gid("gid", Opt_gid),
+ {},
+};
+
+static int efivarfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+ struct efivarfs_fs_info *sbi = fc->s_fs_info;
+ struct efivarfs_mount_opts *opts = &sbi->mount_opts;
+ struct fs_parse_result result;
+ int opt;
+
+ opt = fs_parse(fc, efivarfs_parameters, param, &result);
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case Opt_uid:
+ opts->uid = result.uid;
+ break;
+ case Opt_gid:
+ opts->gid = result.gid;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
static int efivarfs_fill_super(struct super_block *sb, struct fs_context *fc)
{
+ struct efivarfs_fs_info *sfi = sb->s_fs_info;
struct inode *inode = NULL;
struct dentry *root;
int err;
- if (!efivar_is_available())
- return -EOPNOTSUPP;
-
sb->s_maxbytes = MAX_LFS_FILESIZE;
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
@@ -259,13 +330,13 @@ static int efivarfs_fill_super(struct super_block *sb, struct fs_context *fc)
if (!root)
return -ENOMEM;
- INIT_LIST_HEAD(&efivarfs_list);
-
- err = efivar_init(efivarfs_callback, (void *)sb, true, &efivarfs_list);
+ sfi->sb = sb;
+ sfi->nb.notifier_call = efivarfs_ops_notifier;
+ err = blocking_notifier_chain_register(&efivar_ops_nh, &sfi->nb);
if (err)
- efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL);
+ return err;
- return err;
+ return efivar_init(efivarfs_callback, sb, &sfi->efivarfs_list);
}
static int efivarfs_get_tree(struct fs_context *fc)
@@ -283,13 +354,35 @@ static int efivarfs_reconfigure(struct fs_context *fc)
return 0;
}
+static void efivarfs_free(struct fs_context *fc)
+{
+ kfree(fc->s_fs_info);
+}
+
static const struct fs_context_operations efivarfs_context_ops = {
.get_tree = efivarfs_get_tree,
+ .parse_param = efivarfs_parse_param,
.reconfigure = efivarfs_reconfigure,
+ .free = efivarfs_free,
};
static int efivarfs_init_fs_context(struct fs_context *fc)
{
+ struct efivarfs_fs_info *sfi;
+
+ if (!efivar_is_available())
+ return -EOPNOTSUPP;
+
+ sfi = kzalloc(sizeof(*sfi), GFP_KERNEL);
+ if (!sfi)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&sfi->efivarfs_list);
+
+ sfi->mount_opts.uid = GLOBAL_ROOT_UID;
+ sfi->mount_opts.gid = GLOBAL_ROOT_GID;
+
+ fc->s_fs_info = sfi;
fc->ops = &efivarfs_context_ops;
return 0;
}
@@ -298,13 +391,11 @@ static void efivarfs_kill_sb(struct super_block *sb)
{
struct efivarfs_fs_info *sfi = sb->s_fs_info;
+ blocking_notifier_chain_unregister(&efivar_ops_nh, &sfi->nb);
kill_litter_super(sb);
- if (!efivar_is_available())
- return;
-
/* Remove all entries and destroy */
- efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL);
+ efivar_entry_iter(efivarfs_destroy, &sfi->efivarfs_list, NULL);
kfree(sfi);
}
@@ -313,6 +404,7 @@ static struct file_system_type efivarfs_type = {
.name = "efivarfs",
.init_fs_context = efivarfs_init_fs_context,
.kill_sb = efivarfs_kill_sb,
+ .parameters = efivarfs_parameters,
};
static __init int efivarfs_init(void)
generated by cgit v1.2.3 (git 2.39.0) at 2025-08-29 09:39:15 +0300