Commit ac046f1d authored by Peng Tao's avatar Peng Tao Committed by Theodore Ts'o

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: [<c039d282>] _spin_lock+0x8/0x19
*pde = 00000000 
Oops: 0002 [#1] SMP
Signed-off-by: default avatarPeng Tao <bergwolf@gmail.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent e6b5d301
......@@ -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);
......
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