@@ -606,6 +606,8 @@ enum {
#define EXT4_IOC_ALLOC_DA_BLKS _IO('f', 12)
#define EXT4_IOC_MOVE_EXT _IOWR('f', 15, struct move_extent)
#define EXT4_IOC_RESIZE_FS _IOW('f', 16, __u64)
+#define EXT4_IOC_GET_EXPOSE_STALE _IOR('f', 17, int)
+#define EXT4_IOC_SET_EXPOSE_STALE _IOW('f', 18, int)
#if defined(__KERNEL__) && defined(CONFIG_COMPAT)
/*
@@ -925,6 +927,9 @@ struct ext4_inode_info {
/* Precomputed uuid+inum+igen checksum for seeding inode checksums */
__u32 i_csum_seed;
+
+ /* expose stale data in creating a new extent */
+ int i_expose_stale_data;
};
/*
@@ -4336,6 +4336,7 @@ static void ext4_falloc_update_inode(struct inode *inode,
long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
{
struct inode *inode = file->f_path.dentry->d_inode;
+ struct ext4_inode_info *ei = EXT4_I(inode);
handle_t *handle;
loff_t new_size;
unsigned int max_blocks;
@@ -4379,7 +4380,10 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
return ret;
}
- flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT;
+ if (ei->i_expose_stale_data)
+ flags = EXT4_GET_BLOCKS_CREATE;
+ else
+ flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT;
if (mode & FALLOC_FL_KEEP_SIZE)
flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
/*
@@ -445,6 +445,47 @@ resizefs_out:
return 0;
}
+ case EXT4_IOC_GET_EXPOSE_STALE: {
+ int enable;
+
+ /* security check */
+ if (!capable(CAP_SYS_RAWIO))
+ return -EPERM;
+
+ /*
+ * currently only extent-based files support (pre)allocate with
+ * EXPOSE_STALE_DATA flag
+ */
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
+ return -EOPNOTSUPP;
+
+ enable = ei->i_expose_stale_data;
+
+ return put_user(enable, (int __user *) arg);
+ }
+
+ case EXT4_IOC_SET_EXPOSE_STALE: {
+ int enable;
+
+ /* security check */
+ if (!capable(CAP_SYS_RAWIO))
+ return -EPERM;
+
+ /*
+ * currently only extent-based files support (pre)allocate with
+ * EXPOSE_STALE_DATA flag
+ */
+ if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
+ return -EOPNOTSUPP;
+
+ if (get_user(enable, (int __user *) arg))
+ return -EFAULT;
+
+ ei->i_expose_stale_data = enable;
+
+ return 0;
+ }
+
default:
return -ENOTTY;
}
@@ -508,6 +549,8 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case EXT4_IOC_MOVE_EXT:
case FITRIM:
case EXT4_IOC_RESIZE_FS:
+ case EXT4_IOC_GET_EXPOSE_STALE:
+ case EXT4_IOC_SET_EXPOSE_STALE:
break;
default:
return -ENOIOCTLCMD;
@@ -988,6 +988,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
ei->i_datasync_tid = 0;
atomic_set(&ei->i_ioend_count, 0);
atomic_set(&ei->i_aiodio_unwritten, 0);
+ ei->i_expose_stale_data = 0;
return &ei->vfs_inode;
}