add-getstate-ioctl

   1 ext4: add a new ioctl EXT4_IOC_GETSTATE
   2
   3 The new ioctl EXT4_IOC_GETSTATE returns some of the dynamic state of
   4 an ext4 inode for debugging purposes.
   5
   6 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
   7 ---
   8  fs/ext4/ext4.h  | 11 +++++++++++
   9  fs/ext4/ioctl.c | 17 +++++++++++++++++
  10  2 files changed, 28 insertions(+)
  11
  12 diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
  13 index b22f24f1d365..ee296797bcd2 100644
  14 --- a/fs/ext4/ext4.h
  15 +++ b/fs/ext4/ext4.h
  16 @@ -651,6 +651,7 @@ enum {
  17  #define EXT4_IOC_GET_ENCRYPTION_POLICY FS_IOC_GET_ENCRYPTION_POLICY
  18  /* ioctl codes 19--39 are reserved for fscrypt */
  19  #define EXT4_IOC_CLEAR_ES_CACHE                _IO('f', 40)
  20 +#define EXT4_IOC_GETSTATE              _IOW('f', 41, __u32)
  21
  22  #define EXT4_IOC_FSGETXATTR            FS_IOC_FSGETXATTR
  23  #define EXT4_IOC_FSSETXATTR            FS_IOC_FSSETXATTR
  24 @@ -664,6 +665,16 @@ enum {
  25  #define EXT4_GOING_FLAGS_LOGFLUSH              0x1     /* flush log but not data */
  26  #define EXT4_GOING_FLAGS_NOLOGFLUSH            0x2     /* don't flush log nor data */
  27
  28 +/*
  29 + * Flags returned by EXT4_IOC_GETSTATE
  30 + *
  31 + * We only expose to userspace a subset of the state flags in
  32 + * i_state_flags
  33 + */
  34 +#define EXT4_STATE_FLAG_EXT_PRECACHED  0x00000001
  35 +#define EXT4_STATE_FLAG_NEW            0x00000002
  36 +#define EXT4_STATE_FLAG_NEWENTRY       0x00000004
  37 +#define EXT4_STATE_FLAG_DA_ALLOC_CLOSE 0x00000008
  38
  39  #if defined(__KERNEL__) && defined(CONFIG_COMPAT)
  40  /*
  41 diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
  42 index 15b1047878ab..ffb7bde4900d 100644
  43 --- a/fs/ext4/ioctl.c
  44 +++ b/fs/ext4/ioctl.c
  45 @@ -1123,6 +1123,22 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  46                 return 0;
  47         }
  48
  49 +       case EXT4_IOC_GETSTATE:
  50 +       {
  51 +               __u32   state = 0;
  52 +
  53 +               if (ext4_test_inode_state(inode, EXT4_STATE_EXT_PRECACHED))
  54 +                       state |= EXT4_STATE_FLAG_EXT_PRECACHED;
  55 +               if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
  56 +                       state |= EXT4_STATE_FLAG_NEW;
  57 +               if (ext4_test_inode_state(inode, EXT4_STATE_NEWENTRY))
  58 +                       state |= EXT4_STATE_FLAG_NEWENTRY;
  59 +               if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE))
  60 +                       state |= EXT4_STATE_FLAG_DA_ALLOC_CLOSE;
  61 +
  62 +               return put_user(state, (__u32 __user *) arg);
  63 +       }
  64 +
  65         case EXT4_IOC_FSGETXATTR:
  66         {
  67                 struct fsxattr fa;
  68 @@ -1242,6 +1258,7 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  69         case EXT4_IOC_SHUTDOWN:
  70         case FS_IOC_GETFSMAP:
  71         case EXT4_IOC_CLEAR_ES_CACHE:
  72 +       case EXT4_IOC_GETSTATE:
  73                 break;
  74         default:
  75                 return -ENOIOCTLCMD;