vfs: mnt_drop_write_file()

new helper (wrapper around mnt_drop_write()) to be used in pair with
mnt_want_write_file().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Conflicts:
	fs/inode.c
	fs/ext4/ioctl.c
	fs/xfs/xfs_ioctl.c

Change-Id: Idcde3c3eba747966dcfc692f1a2f473cbfdf050a

21 files changed, 53 insertions, 46 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 5deabce82a8..757c33f1eb6 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -253,7 +253,7 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
 	inode->i_ctime = CURRENT_TIME;
 	btrfs_end_transaction(trans, root);
 
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 
 	ret = 0;
  out_unlock:
@@ -1940,7 +1940,7 @@ out_dput:
 	dput(dentry);
 out_unlock_dir:
 	mutex_unlock(&dir->i_mutex);
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 out:
 	kfree(vol_args);
 	return err;
@@ -2009,7 +2009,7 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
 		ret = -EINVAL;
 	}
 out:
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 	return ret;
 }
 
@@ -2453,7 +2453,7 @@ out_unlock:
 out_fput:
 	fput(src_file);
 out_drop_write:
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 	return ret;
 }
 
@@ -2508,7 +2508,7 @@ static long btrfs_ioctl_trans_start(struct file *file)
 
 out_drop:
 	atomic_dec(&root->fs_info->open_ioctl_trans);
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 out:
 	return ret;
 }
@@ -2743,7 +2743,7 @@ long btrfs_ioctl_trans_end(struct file *file)
 
 	atomic_dec(&root->fs_info->open_ioctl_trans);
 
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 	return 0;
 }
 
diff --git a/fs/ext2/ioctl.c b/fs/ext2/ioctl.c
index 61a3f966172..1089f760c84 100644
--- a/fs/ext2/ioctl.c
+++ b/fs/ext2/ioctl.c
@@ -83,7 +83,7 @@ long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		inode->i_ctime = CURRENT_TIME_SEC;
 		mark_inode_dirty(inode);
 setflags_out:
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return ret;
 	}
 	case EXT2_IOC_GETVERSION:
@@ -100,7 +100,7 @@ setflags_out:
 			inode->i_ctime = CURRENT_TIME_SEC;
 			mark_inode_dirty(inode);
 		}
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return ret;
 	case EXT2_IOC_GETRSVSZ:
 		if (test_opt(inode->i_sb, RESERVATION)
@@ -145,7 +145,7 @@ setflags_out:
 			rsv->rsv_goal_size = rsv_window_size;
 		}
 		mutex_unlock(&ei->truncate_mutex);
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return 0;
 	}
 	default:
diff --git a/fs/ext3/ioctl.c b/fs/ext3/ioctl.c
index a5cad00884b..24f189fcb7a 100644
--- a/fs/ext3/ioctl.c
+++ b/fs/ext3/ioctl.c
@@ -110,7 +110,7 @@ flags_err:
 			err = ext3_change_inode_journal_flag(inode, jflag);
 flags_out:
 		mutex_unlock(&inode->i_mutex);
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return err;
 	}
 	case EXT3_IOC_GETVERSION:
@@ -147,7 +147,7 @@ flags_out:
 		}
 		ext3_journal_stop(handle);
 setversion_out:
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return err;
 	}
 #ifdef CONFIG_JBD_DEBUG
@@ -219,7 +219,7 @@ setversion_out:
 		}
 		mutex_unlock(&ei->truncate_mutex);
 setrsvsz_out:
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return err;
 	}
 	case EXT3_IOC_GROUP_EXTEND: {
@@ -245,7 +245,7 @@ setrsvsz_out:
 		if (err == 0)
 			err = err2;
 group_extend_out:
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return err;
 	}
 	case EXT3_IOC_GROUP_ADD: {
@@ -273,7 +273,7 @@ group_extend_out:
 		if (err == 0)
 			err = err2;
 group_add_out:
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return err;
 	}
 	case FITRIM: {
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 0fd89e4b4d4..c213075c08c 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -138,7 +138,7 @@ flags_err:
 			err = ext4_ext_migrate(inode);
 flags_out:
 		mutex_unlock(&inode->i_mutex);
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return err;
 	}
 	case EXT4_IOC_GETVERSION:
@@ -175,7 +175,7 @@ flags_out:
 		}
 		ext4_journal_stop(handle);
 setversion_out:
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return err;
 	}
 #ifdef CONFIG_JBD2_DEBUG
@@ -225,7 +225,7 @@ setversion_out:
 		}
 		if (err == 0)
 			err = err2;
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 
 		return err;
 	}
@@ -259,7 +259,7 @@ setversion_out:
 
 		err = ext4_move_extents(filp, donor_filp, me.orig_start,
 					me.donor_start, me.len, &me.moved_len);
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		if (me.moved_len > 0)
 			file_remove_suid(donor_filp);
 
@@ -295,7 +295,7 @@ mext_out:
 		}
 		if (err == 0)
 			err = err2;
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 
 		return err;
 	}
@@ -318,7 +318,7 @@ mext_out:
 		mutex_lock(&(inode->i_mutex));
 		err = ext4_ext_migrate(inode);
 		mutex_unlock(&(inode->i_mutex));
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return err;
 	}
 
@@ -332,7 +332,7 @@ mext_out:
 		if (err)
 			return err;
 		err = ext4_alloc_da_blocks(inode);
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return err;
 	}
 
diff --git a/fs/fat/file.c b/fs/fat/file.c
index 20334aaa5e5..938255b8f6d 100644
--- a/fs/fat/file.c
+++ b/fs/fat/file.c
@@ -108,7 +108,7 @@ static int fat_ioctl_set_attributes(struct file *file, u32 __user *user_attr)
 	fat_save_attrs(inode, attr);
 	mark_inode_dirty(inode);
 out_drop_write:
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 out_unlock_inode:
 	mutex_unlock(&inode->i_mutex);
 out:
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 8d14f4b7a35..0cd3dc888d8 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -274,7 +274,7 @@ out_trans_end:
 out:
 	gfs2_glock_dq_uninit(&gh);
 out_drop_write:
-	mnt_drop_write(filp->f_path.mnt);
+	mnt_drop_write_file(filp);
 	return error;
 }
 
diff --git a/fs/hfsplus/ioctl.c b/fs/hfsplus/ioctl.c
index 31d3fe57642..f66c7655b3f 100644
--- a/fs/hfsplus/ioctl.c
+++ b/fs/hfsplus/ioctl.c
@@ -94,7 +94,7 @@ static int hfsplus_ioctl_setflags(struct file *file, int __user *user_flags)
 out_unlock_inode:
 	mutex_unlock(&inode->i_mutex);
 out_drop_write:
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 out:
 	return err;
 }
diff --git a/fs/inode.c b/fs/inode.c
index 660c9871b44..8f021d04f3a 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1546,7 +1546,7 @@ int file_update_time(struct file *file)
 		return 0;
 
 	ret = update_time(inode, &now, sync_it);
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 
 	return ret;
 }
diff --git a/fs/jfs/ioctl.c b/fs/jfs/ioctl.c
index 73d9eaa91c0..f19d1e04a37 100644
--- a/fs/jfs/ioctl.c
+++ b/fs/jfs/ioctl.c
@@ -120,7 +120,7 @@ long jfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 		inode->i_ctime = CURRENT_TIME_SEC;
 		mark_inode_dirty(inode);
 setflags_out:
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return err;
 	}
 	default:
diff --git a/fs/namespace.c b/fs/namespace.c
index ef0d97fdd67..2414feb8e83 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -419,6 +419,12 @@ void mnt_drop_write(struct vfsmount *mnt)
 }
 EXPORT_SYMBOL_GPL(mnt_drop_write);
 
+void mnt_drop_write_file(struct file *file)
+{
+	mnt_drop_write(file->f_path.mnt);
+}
+EXPORT_SYMBOL(mnt_drop_write_file);
+
 static int mnt_make_readonly(struct vfsmount *mnt)
 {
 	int ret = 0;
diff --git a/fs/ncpfs/ioctl.c b/fs/ncpfs/ioctl.c
index 790e92a9ec6..6958adfaff0 100644
--- a/fs/ncpfs/ioctl.c
+++ b/fs/ncpfs/ioctl.c
@@ -901,7 +901,7 @@ long ncp_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	ret = __ncp_ioctl(inode, cmd, arg);
 outDropWrite:
 	if (need_drop_write)
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 out:
 	return ret;
 }
diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
index dead2b51502..a4348df7982 100644
--- a/fs/nfsd/nfs4recover.c
+++ b/fs/nfsd/nfs4recover.c
@@ -151,7 +151,7 @@ nfsd4_create_clid_dir(struct nfs4_client *clp)
 	if (status)
 		goto out_put;
 	status = vfs_mkdir(dir->d_inode, dentry, S_IRWXU);
-	mnt_drop_write(rec_file->f_path.mnt);
+	mnt_drop_write_file(rec_file);
 out_put:
 	dput(dentry);
 out_unlock:
@@ -289,7 +289,7 @@ nfsd4_remove_clid_dir(struct nfs4_client *clp)
 	nfs4_reset_creds(original_cred);
 	if (status == 0)
 		vfs_fsync(rec_file, 0);
-	mnt_drop_write(rec_file->f_path.mnt);
+	mnt_drop_write_file(rec_file);
 out:
 	if (status)
 		printk("NFSD: Failed to remove expired client state directory"
@@ -325,7 +325,7 @@ nfsd4_recdir_purge_old(void) {
 	status = nfsd4_list_rec_dir(rec_file->f_path.dentry, purge_old);
 	if (status == 0)
 		vfs_fsync(rec_file, 0);
-	mnt_drop_write(rec_file->f_path.mnt);
+	mnt_drop_write_file(rec_file);
 out:
 	if (status)
 		printk("nfsd4: failed to purge old clients from recovery"
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index db3790dd560..bbc0f8d9406 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -27,7 +27,7 @@
 #include <linux/uaccess.h>	/* copy_from_user(), copy_to_user() */
 #include <linux/vmalloc.h>
 #include <linux/compat.h>	/* compat_ptr() */
-#include <linux/mount.h>	/* mnt_want_write_file(), mnt_drop_write() */
+#include <linux/mount.h>	/* mnt_want_write_file(), mnt_drop_write_file() */
 #include <linux/buffer_head.h>
 #include <linux/nilfs2_fs.h>
 #include "nilfs.h"
@@ -154,7 +154,7 @@ static int nilfs_ioctl_setflags(struct inode *inode, struct file *filp,
 	ret = nilfs_transaction_commit(inode->i_sb);
 out:
 	mutex_unlock(&inode->i_mutex);
-	mnt_drop_write(filp->f_path.mnt);
+	mnt_drop_write_file(filp);
 	return ret;
 }
 
@@ -194,7 +194,7 @@ static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
 
 	mutex_unlock(&nilfs->ns_snapshot_mount_mutex);
 out:
-	mnt_drop_write(filp->f_path.mnt);
+	mnt_drop_write_file(filp);
 	return ret;
 }
 
@@ -225,7 +225,7 @@ nilfs_ioctl_delete_checkpoint(struct inode *inode, struct file *filp,
 	else
 		nilfs_transaction_commit(inode->i_sb); /* never fails */
 out:
-	mnt_drop_write(filp->f_path.mnt);
+	mnt_drop_write_file(filp);
 	return ret;
 }
 
@@ -675,7 +675,7 @@ out_free:
 		vfree(kbufs[n]);
 	kfree(kbufs[4]);
 out:
-	mnt_drop_write(filp->f_path.mnt);
+	mnt_drop_write_file(filp);
 	return ret;
 }
 
@@ -721,7 +721,7 @@ static int nilfs_ioctl_resize(struct inode *inode, struct file *filp,
 	ret = nilfs_resize_fs(inode->i_sb, newsize);
 
 out_drop_write:
-	mnt_drop_write(filp->f_path.mnt);
+	mnt_drop_write_file(filp);
 out:
 	return ret;
 }
diff --git a/fs/ocfs2/ioctl.c b/fs/ocfs2/ioctl.c
index d15042e30c5..00cfa228716 100644
--- a/fs/ocfs2/ioctl.c
+++ b/fs/ocfs2/ioctl.c
@@ -910,7 +910,7 @@ long ocfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			return status;
 		status = ocfs2_set_inode_attr(inode, flags,
 			OCFS2_FL_MODIFIABLE);
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		return status;
 	case OCFS2_IOC_RESVSP:
 	case OCFS2_IOC_RESVSP64:
diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c
index 037085f13ef..b44988392dd 100644
--- a/fs/ocfs2/move_extents.c
+++ b/fs/ocfs2/move_extents.c
@@ -1146,7 +1146,7 @@ out:
 
 	kfree(context);
 
-	mnt_drop_write(filp->f_path.mnt);
+	mnt_drop_write_file(filp);
 
 	return status;
 }
diff --git a/fs/open.c b/fs/open.c
index bf00a8652a8..3cb383b7c85 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -630,7 +630,7 @@ SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)
 	dentry = file->f_path.dentry;
 	audit_inode(NULL, dentry);
 	error = chown_common(&file->f_path, user, group);
-	mnt_drop_write(file->f_path.mnt);
+	mnt_drop_write_file(file);
 out_fput:
 	fput(file);
 out:
diff --git a/fs/reiserfs/ioctl.c b/fs/reiserfs/ioctl.c
index 0b94d7b2b11..950e3d1b5c9 100644
--- a/fs/reiserfs/ioctl.c
+++ b/fs/reiserfs/ioctl.c
@@ -96,7 +96,7 @@ long reiserfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 			inode->i_ctime = CURRENT_TIME_SEC;
 			mark_inode_dirty(inode);
 setflags_out:
-			mnt_drop_write(filp->f_path.mnt);
+			mnt_drop_write_file(filp);
 			break;
 		}
 	case REISERFS_IOC_GETVERSION:
@@ -117,7 +117,7 @@ setflags_out:
 		inode->i_ctime = CURRENT_TIME_SEC;
 		mark_inode_dirty(inode);
 setversion_out:
-		mnt_drop_write(filp->f_path.mnt);
+		mnt_drop_write_file(filp);
 		break;
 	default:
 		err = -ENOTTY;
diff --git a/fs/ubifs/ioctl.c b/fs/ubifs/ioctl.c
index e52c84598fe..1a7e2d8bdbe 100644
--- a/fs/ubifs/ioctl.c
+++ b/fs/ubifs/ioctl.c
@@ -178,7 +178,7 @@ long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 			return err;
 		dbg_gen("set flags: %#x, i_flags %#x", flags, inode->i_flags);
 		err = setflags(inode, flags);
-		mnt_drop_write(file->f_path.mnt);
+		mnt_drop_write_file(file);
 		return err;
 	}
 
diff --git a/fs/xattr.c b/fs/xattr.c
index f060663ab70..54f7408319e 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -336,7 +336,7 @@ SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name,
 	error = mnt_want_write_file(f);
 	if (!error) {
 		error = setxattr(dentry, name, value, size, flags);
-		mnt_drop_write(f->f_path.mnt);
+		mnt_drop_write_file(f);
 	}
 	fput(f);
 	return error;
@@ -563,7 +563,7 @@ SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name)
 	error = mnt_want_write_file(f);
 	if (!error) {
 		error = removexattr(dentry, name);
-		mnt_drop_write(f->f_path.mnt);
+		mnt_drop_write_file(f);
 	}
 	fput(f);
 	return error;
diff --git a/fs/xfs/linux-2.6/xfs_ioctl32.c b/fs/xfs/linux-2.6/xfs_ioctl32.c
index dd4ba1d4c58..f9ccb7b7c04 100644
--- a/fs/xfs/linux-2.6/xfs_ioctl32.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl32.c
@@ -461,7 +461,7 @@ xfs_compat_attrmulti_by_handle(
 					dentry->d_inode, attr_name,
 					compat_ptr(ops[i].am_attrvalue),
 					ops[i].am_length, ops[i].am_flags);
-			mnt_drop_write(parfilp->f_path.mnt);
+			mnt_drop_write_file(parfilp);
 			break;
 		case ATTR_OP_REMOVE:
 			ops[i].am_error = mnt_want_write_file(parfilp);
@@ -470,7 +470,7 @@ xfs_compat_attrmulti_by_handle(
 			ops[i].am_error = xfs_attrmulti_attr_remove(
 					dentry->d_inode, attr_name,
 					ops[i].am_flags);
-			mnt_drop_write(parfilp->f_path.mnt);
+			mnt_drop_write_file(parfilp);
 			break;
 		default:
 			ops[i].am_error = EINVAL;
diff --git a/include/linux/mount.h b/include/linux/mount.h
index c2e704c7d75..fe90f576f6d 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -93,6 +93,7 @@ extern int mnt_want_write(struct vfsmount *mnt);
 extern int mnt_want_write_file(struct file *file);
 extern int mnt_clone_write(struct vfsmount *mnt);
 extern void mnt_drop_write(struct vfsmount *mnt);
+extern void mnt_drop_write_file(struct file *file);
 extern void mntput(struct vfsmount *mnt);
 extern struct vfsmount *mntget(struct vfsmount *mnt);
 extern void mnt_pin(struct vfsmount *mnt);