diff options
Diffstat (limited to 'fs/efivarfs/super.c')
| -rw-r--r-- | fs/efivarfs/super.c | 39 |
1 files changed, 38 insertions, 1 deletions
diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c index 482d612b716b..e028fafa04f3 100644 --- a/fs/efivarfs/super.c +++ b/fs/efivarfs/super.c @@ -13,6 +13,7 @@ #include <linux/ucs2_string.h> #include <linux/slab.h> #include <linux/magic.h> +#include <linux/statfs.h> #include "internal.h" @@ -23,8 +24,44 @@ static void efivarfs_evict_inode(struct inode *inode) clear_inode(inode); } +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; + efi_status_t status; + + status = efivar_query_variable_info(attr, &storage_space, &remaining_space, + &max_variable_size); + if (status != EFI_SUCCESS) + return efi_status_to_err(status); + + /* + * This is not a normal filesystem, so no point in pretending it has a block + * size; we declare f_bsize to 1, so that we can then report the exact value + * sent by EFI QueryVariableInfo in f_blocks and f_bfree + */ + buf->f_bsize = 1; + buf->f_namelen = NAME_MAX; + buf->f_blocks = storage_space; + buf->f_bfree = remaining_space; + buf->f_type = dentry->d_sb->s_magic; + + /* + * In f_bavail we declare the free space that the kernel will allow writing + * when the storage_paranoia x86 quirk is active. To use more, users + * should boot the kernel with efi_no_storage_paranoia. + */ + if (remaining_space > efivar_reserved_space()) + buf->f_bavail = remaining_space - efivar_reserved_space(); + else + buf->f_bavail = 0; + + return 0; +} static const struct super_operations efivarfs_ops = { - .statfs = simple_statfs, + .statfs = efivarfs_statfs, .drop_inode = generic_delete_inode, .evict_inode = efivarfs_evict_inode, }; |