Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 03046886 authored by vikram.jadhav07's avatar vikram.jadhav07 Committed by Theodore Ts'o
Browse files

ext4: clean up error handling in the MMP support 



There is memory leak as both caller function kmmpd() and callee
read_mmp_block() not releasing bh_check  (i.e buffer_head).
Given patch fixes this problem.

[ Additional changes suggested by Andreas Dilger -- TYT ]

Signed-off-by: default avatarJadhav Vikram <vikramjadhavpucsd2007@gmail.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 490c1b44

fs/ext4/mmp.c

+17 −17
Original line number Original line Diff line number Diff line
@@ -91,21 +91,22 @@ static int read_mmp_block(struct super_block *sb, struct buffer_head **bh, 
	submit_bh(READ_SYNC | REQ_META | REQ_PRIO, *bh);

	submit_bh(READ_SYNC | REQ_META | REQ_PRIO, *bh);

	wait_on_buffer(*bh);

	wait_on_buffer(*bh);

	if (!buffer_uptodate(*bh)) {

	if (!buffer_uptodate(*bh)) {

		brelse(*bh);

		*bh = NULL;

		ret = -EIO;

		ret = -EIO;

		goto warn_exit;

		goto warn_exit;

	}

	}



	mmp = (struct mmp_struct *)((*bh)->b_data);

	mmp = (struct mmp_struct *)((*bh)->b_data);

	if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC)

	if (le32_to_cpu(mmp->mmp_magic) != EXT4_MMP_MAGIC) {

		ret = -EFSCORRUPTED;

		ret = -EFSCORRUPTED;

	else if (!ext4_mmp_csum_verify(sb, mmp))

		goto warn_exit;

	}

	if (!ext4_mmp_csum_verify(sb, mmp)) {

		ret = -EFSBADCRC;

		ret = -EFSBADCRC;

	else

		goto warn_exit;

	}

	return 0;

	return 0;



warn_exit:

warn_exit:

	brelse(*bh);

	*bh = NULL;

	ext4_warning(sb, "Error %d while reading MMP block %llu",

	ext4_warning(sb, "Error %d while reading MMP block %llu",

		     ret, mmp_block);

		     ret, mmp_block);

	return ret;

	return ret;
@@ -181,15 +182,13 @@ static int kmmpd(void *data) 
		    EXT4_FEATURE_INCOMPAT_MMP)) {

		    EXT4_FEATURE_INCOMPAT_MMP)) {

			ext4_warning(sb, "kmmpd being stopped since MMP feature"

			ext4_warning(sb, "kmmpd being stopped since MMP feature"

				     " has been disabled.");

				     " has been disabled.");

			EXT4_SB(sb)->s_mmp_tsk = NULL;

			goto exit_thread;

			goto failed;

		}

		}





		if (sb->s_flags & MS_RDONLY) {

		if (sb->s_flags & MS_RDONLY) {

			ext4_warning(sb, "kmmpd being stopped since filesystem "

			ext4_warning(sb, "kmmpd being stopped since filesystem "

				     "has been remounted as readonly.");

				     "has been remounted as readonly.");

			EXT4_SB(sb)->s_mmp_tsk = NULL;

			goto exit_thread;

			goto failed;

		}

		}





		diff = jiffies - last_update_time;

		diff = jiffies - last_update_time;
@@ -211,9 +210,7 @@ static int kmmpd(void *data) 
			if (retval) {

			if (retval) {

				ext4_error(sb, "error reading MMP data: %d",

				ext4_error(sb, "error reading MMP data: %d",

					   retval);

					   retval);



				goto exit_thread;

				EXT4_SB(sb)->s_mmp_tsk = NULL;

				goto failed;

			}

			}





			mmp_check = (struct mmp_struct *)(bh_check->b_data);

			mmp_check = (struct mmp_struct *)(bh_check->b_data);
@@ -225,7 +222,9 @@ static int kmmpd(void *data) 
					     "The filesystem seems to have been"

					     "The filesystem seems to have been"

					     " multiply mounted.");

					     " multiply mounted.");

				ext4_error(sb, "abort");

				ext4_error(sb, "abort");

				goto failed;

				put_bh(bh_check);

				retval = -EBUSY;

				goto exit_thread;

			}

			}

			put_bh(bh_check);

			put_bh(bh_check);

		}

		}
@@ -248,7 +247,8 @@ static int kmmpd(void *data) 




	retval = write_mmp_block(sb, bh);

	retval = write_mmp_block(sb, bh);





failed:

exit_thread:

	EXT4_SB(sb)->s_mmp_tsk = NULL;

	kfree(data);

	kfree(data);

	brelse(bh);

	brelse(bh);

	return retval;

	return retval;