ext4: remove the obsolete/broken EXT4_IOC_WAIT_FOR_READONLY ioctl

There are no users of the EXT4_IOC_WAIT_FOR_READONLY ioctl, and it is
also broken.  No one sets the set_ro_timer, no one wakes up us and our
state is set to TASK_INTERRUPTIBLE not RUNNING.  So remove it.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 61b0b5c..4546da4 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -564,9 +564,6 @@ struct ext4_new_group_data {
 #define        EXT4_IOC_SETVERSION             _IOW('f', 4, long)
 #define        EXT4_IOC_GETVERSION_OLD         FS_IOC_GETVERSION
 #define        EXT4_IOC_SETVERSION_OLD         FS_IOC_SETVERSION
-#ifdef CONFIG_JBD2_DEBUG
-#define EXT4_IOC_WAIT_FOR_READONLY     _IOR('f', 99, long)
-#endif
 #define EXT4_IOC_GETRSVSZ              _IOR('f', 5, long)
 #define EXT4_IOC_SETRSVSZ              _IOW('f', 6, long)
 #define EXT4_IOC_GROUP_EXTEND          _IOW('f', 7, unsigned long)
@@ -589,9 +586,6 @@ struct ext4_new_group_data {
 #define EXT4_IOC32_SETRSVSZ            _IOW('f', 6, int)
 #define EXT4_IOC32_GROUP_EXTEND                _IOW('f', 7, unsigned int)
 #define EXT4_IOC32_GROUP_ADD           _IOW('f', 8, struct compat_ext4_new_group_input)
-#ifdef CONFIG_JBD2_DEBUG
-#define EXT4_IOC32_WAIT_FOR_READONLY   _IOR('f', 99, int)
-#endif
 #define EXT4_IOC32_GETVERSION_OLD      FS_IOC32_GETVERSION
 #define EXT4_IOC32_SETVERSION_OLD      FS_IOC32_SETVERSION
 #endif
@@ -1171,10 +1165,6 @@ struct ext4_sb_info {
        u32 s_max_batch_time;
        u32 s_min_batch_time;
        struct block_device *journal_bdev;
-#ifdef CONFIG_JBD2_DEBUG
-       struct timer_list turn_ro_timer;        /* For turning read-only (crash simulation) */
-       wait_queue_head_t ro_wait_queue;        /* For people waiting for the fs to go read-only */
-#endif
 #ifdef CONFIG_QUOTA
        char *s_qf_names[MAXQUOTAS];            /* Names of quota files with journalled quota */
        int s_jquota_fmt;                       /* Format of quota to use */

diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 2046d69..8f7ea69 100644 (file)
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -174,29 +174,6 @@ setversion_out:
                mnt_drop_write(filp->f_path.mnt);
                return err;
        }
-#ifdef CONFIG_JBD2_DEBUG
-       case EXT4_IOC_WAIT_FOR_READONLY:
-               /*
-                * This is racy - by the time we're woken up and running,
-                * the superblock could be released.  And the module could
-                * have been unloaded.  So sue me.
-                *
-                * Returns 1 if it slept, else zero.
-                */
-               {
-                       DECLARE_WAITQUEUE(wait, current);
-                       int ret = 0;
-
-                       set_current_state(TASK_INTERRUPTIBLE);
-                       add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
-                       if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
-                               schedule();
-                               ret = 1;
-                       }
-                       remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
-                       return ret;
-               }
-#endif
        case EXT4_IOC_GROUP_EXTEND: {
                ext4_fsblk_t n_blocks_count;
                int err, err2=0;
@@ -421,11 +398,6 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
        case EXT4_IOC32_SETVERSION_OLD:
                cmd = EXT4_IOC_SETVERSION_OLD;
                break;
-#ifdef CONFIG_JBD2_DEBUG
-       case EXT4_IOC32_WAIT_FOR_READONLY:
-               cmd = EXT4_IOC_WAIT_FOR_READONLY;
-               break;
-#endif
        case EXT4_IOC32_GETRSVSZ:
                cmd = EXT4_IOC_GETRSVSZ;
                break;