From ac046f1d6121ccdda6db66bd88acd52418f489b2 Mon Sep 17 00:00:00 2001 From: Peng Tao Date: Mon, 13 Jul 2009 09:30:17 -0400 Subject: [PATCH] ext4: fix null handler of ioctls in no journal mode The EXT4_IOC_GROUP_ADD and EXT4_IOC_GROUP_EXTEND ioctls should not flush the journal in no_journal mode. Otherwise, running resize2fs on a mounted no_journal partition triggers the following error messages: BUG: unable to handle kernel NULL pointer dereference at 00000014 IP: [] _spin_lock+0x8/0x19 *pde = 00000000 Oops: 0002 [#1] SMP Signed-off-by: Peng Tao Signed-off-by: "Theodore Ts'o" --- fs/ext4/ioctl.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index bb415408fdb6..01f149aea841 100644 --- a/fs/ext4/ioctl.c +++ b/fs/ext4/ioctl.c @@ -192,7 +192,7 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) case EXT4_IOC_GROUP_EXTEND: { ext4_fsblk_t n_blocks_count; struct super_block *sb = inode->i_sb; - int err, err2; + int err, err2=0; if (!capable(CAP_SYS_RESOURCE)) return -EPERM; @@ -205,9 +205,11 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return err; err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count); - jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal); - err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal); - jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal); + if (EXT4_SB(sb)->s_journal) { + jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal); + err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal); + jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal); + } if (err == 0) err = err2; mnt_drop_write(filp->f_path.mnt); @@ -252,7 +254,7 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) case EXT4_IOC_GROUP_ADD: { struct ext4_new_group_data input; struct super_block *sb = inode->i_sb; - int err, err2; + int err, err2=0; if (!capable(CAP_SYS_RESOURCE)) return -EPERM; @@ -266,9 +268,11 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return err; err = ext4_group_add(sb, &input); - jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal); - err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal); - jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal); + if (EXT4_SB(sb)->s_journal) { + jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal); + err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal); + jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal); + } if (err == 0) err = err2; mnt_drop_write(filp->f_path.mnt);