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Commit 4b1f1660 authored by Dmitry Monakhov's avatar Dmitry Monakhov Committed by Theodore Ts'o
Browse files

ext4: add i_data_sem sanity check 



Each caller of ext4_ext_dirty must hold i_data_sem,
The only exception is migration code, let's make it convenient.

Signed-off-by: default avatarDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
parent b27b1535

fs/ext4/extents.c

+2 −0
Original line number Diff line number Diff line
@@ -161,6 +161,8 @@ int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle, 
		     struct inode *inode, struct ext4_ext_path *path)

{

	int err;



	WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));

	if (path->p_bh) {

		ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));

		/* path points to block */

fs/ext4/migrate.c

+7 −0
Original line number Diff line number Diff line
@@ -39,6 +39,8 @@ static int finish_range(handle_t *handle, struct inode *inode, 
	newext.ee_block = cpu_to_le32(lb->first_block);

	newext.ee_len   = cpu_to_le16(lb->last_block - lb->first_block + 1);

	ext4_ext_store_pblock(&newext, lb->first_pblock);

	/* Locking only for convinience since we are operating on temp inode */

	down_write(&EXT4_I(inode)->i_data_sem);

	path = ext4_ext_find_extent(inode, lb->first_block, NULL, 0);



	if (IS_ERR(path)) {
@@ -61,7 +63,9 @@ static int finish_range(handle_t *handle, struct inode *inode, 
	 */

	if (needed && ext4_handle_has_enough_credits(handle,

						EXT4_RESERVE_TRANS_BLOCKS)) {

		up_write((&EXT4_I(inode)->i_data_sem));

		retval = ext4_journal_restart(handle, needed);

		down_write((&EXT4_I(inode)->i_data_sem));

		if (retval)

			goto err_out;

	} else if (needed) {
@@ -70,13 +74,16 @@ static int finish_range(handle_t *handle, struct inode *inode, 
			/*

			 * IF not able to extend the journal restart the journal

			 */

			up_write((&EXT4_I(inode)->i_data_sem));

			retval = ext4_journal_restart(handle, needed);

			down_write((&EXT4_I(inode)->i_data_sem));

			if (retval)

				goto err_out;

		}

	}

	retval = ext4_ext_insert_extent(handle, inode, path, &newext, 0);

err_out:

	up_write((&EXT4_I(inode)->i_data_sem));

	if (path) {

		ext4_ext_drop_refs(path);

		kfree(path);