Commit 2a43a878 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Theodore Ts'o
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ext4: elevate write count for migrate ioctl 



The migrate ioctl writes to the filsystem, so we need to elevate the
write count.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 7ee1ec4c

fs/ext4/ext4.h

+1 −2
Original line number Diff line number Diff line
@@ -1084,8 +1084,7 @@ extern long ext4_ioctl(struct file *, unsigned int, unsigned long); 
extern long ext4_compat_ioctl(struct file *, unsigned int, unsigned long);



/* migrate.c */

extern int ext4_ext_migrate(struct inode *, struct file *, unsigned int,

		       unsigned long);

extern int ext4_ext_migrate(struct inode *);

/* namei.c */

extern int ext4_orphan_add(handle_t *, struct inode *);

extern int ext4_orphan_del(handle_t *, struct inode *);

fs/ext4/ioctl.c

+20 −1
Original line number Diff line number Diff line
@@ -267,7 +267,26 @@ setversion_out: 
	}



	case EXT4_IOC_MIGRATE:

		return ext4_ext_migrate(inode, filp, cmd, arg);

	{

		int err;

		if (!is_owner_or_cap(inode))

			return -EACCES;



		err = mnt_want_write(filp->f_path.mnt);

		if (err)

			return err;

		/*

		 * inode_mutex prevent write and truncate on the file.

		 * Read still goes through. We take i_data_sem in

		 * ext4_ext_swap_inode_data before we switch the

		 * inode format to prevent read.

		 */

		mutex_lock(&(inode->i_mutex));

		err = ext4_ext_migrate(inode);

		mutex_unlock(&(inode->i_mutex));

		mnt_drop_write(filp->f_path.mnt);

		return err;

	}



	default:

		return -ENOTTY;

fs/ext4/migrate.c

+1 −9
Original line number Diff line number Diff line
@@ -447,8 +447,7 @@ static int free_ext_block(handle_t *handle, struct inode *inode) 


}



int ext4_ext_migrate(struct inode *inode, struct file *filp,

				unsigned int cmd, unsigned long arg)

int ext4_ext_migrate(struct inode *inode)

{

	handle_t *handle;

	int retval = 0, i;
@@ -515,12 +514,6 @@ int ext4_ext_migrate(struct inode *inode, struct file *filp, 
	 * trascation that created the inode. Later as and

	 * when we add extents we extent the journal

	 */

	/*

	 * inode_mutex prevent write and truncate on the file. Read still goes

	 * through. We take i_data_sem in ext4_ext_swap_inode_data before we

	 * switch the inode format to prevent read.

	 */

	mutex_lock(&(inode->i_mutex));

	/*

	 * Even though we take i_mutex we can still cause block allocation

	 * via mmap write to holes. If we have allocated new blocks we fail
@@ -623,7 +616,6 @@ err_out: 
	tmp_inode->i_nlink = 0;



	ext4_journal_stop(handle);

	mutex_unlock(&(inode->i_mutex));



	if (tmp_inode)

		iput(tmp_inode);