Re: [PATCH 4/4] Adds ioctl interface support for ext4 project

On Wed 24-09-14 22:04:30, Li Xi wrote:

This patch adds ioctl interface for setting/getting project of ext4.

  One more thing...

Signed-off-by: Li Xi <redacted>
---
 Documentation/filesystems/ext4.txt |    4 ++
 fs/ext4/ext4.h                     |    2 +
 fs/ext4/ioctl.c                    |   85 ++++++++++++++++++++++++++++++++++++
 3 files changed, 91 insertions(+), 0 deletions(-)

+	case EXT4_IOC_SETPROJECT:
+	{
+		__u32 projid;
+		int err;
+		handle_t *handle;
+		kprojid_t kprojid;
+		struct ext4_iloc iloc;
+		struct ext4_inode *raw_inode;
+
+		struct dquot *transfer_to[EXT4_MAXQUOTAS] = { };
+
+		/* Make sure caller can change project. */
+		if (!capable(CAP_SYS_ADMIN))
+			return -EACCES;

  I realized you forgot to check EXT4_FEATURE_RO_COMPAT_PROJECT here...

								Honza

+
+		if (get_user(projid, (__u32 __user *) arg))
+			return -EFAULT;
+
+		kprojid = make_kprojid(&init_user_ns, (projid_t)projid);
+
+		if (projid_eq(kprojid, EXT4_I(inode)->i_projid))
+			return 0;
+
+		err = mnt_want_write_file(filp);
+		if (err)
+			return err;
+
+		err = -EPERM;
+		mutex_lock(&inode->i_mutex);
+		/* Is it quota file? Do not allow user to mess with it */
+		if (IS_NOQUOTA(inode))
+			goto project_out;
+
+		dquot_initialize(inode);
+
+		handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
+			EXT4_QUOTA_INIT_BLOCKS(sb) +
+			EXT4_QUOTA_DEL_BLOCKS(sb) + 3);
+		if (IS_ERR(handle)) {
+			err = PTR_ERR(handle);
+			goto project_out;
+		}
+
+		err = ext4_reserve_inode_write(handle, inode, &iloc);
+		if (err)
+			goto project_stop;
+
+		raw_inode = ext4_raw_inode(&iloc);
+		if ((EXT4_INODE_SIZE(inode->i_sb) <=
+		     EXT4_GOOD_OLD_INODE_SIZE) ||
+		    (!EXT4_FITS_IN_INODE(raw_inode, ei, i_projid))) {
+		    	err = -EFBIG;
+		    	goto project_stop;
+		}
+
+		transfer_to[PRJQUOTA] = dqget(sb, make_kqid_projid(kprojid));
+		if (!transfer_to[PRJQUOTA])
+			goto project_set;
+
+		err = __dquot_transfer(inode, transfer_to);
+		dqput(transfer_to[PRJQUOTA]);
+		if (err)
+			goto project_stop;
+
+project_set:
+		EXT4_I(inode)->i_projid = kprojid;
+		inode->i_ctime = ext4_current_time(inode);
+		err = ext4_mark_iloc_dirty(handle, inode, &iloc);
+project_stop:
+		ext4_journal_stop(handle);
+project_out:
+		mutex_unlock(&inode->i_mutex);
+		mnt_drop_write_file(filp);
+		return err;
+	}
 	default:
 		return -ENOTTY;
 	}
-- 
1.7.1

-- 
Jan Kara [off-list ref]
SUSE Labs, CR