jbd2: Fix oops in jbd2_journal_file_inode()

Commit 0713ed0cde76438d05849f1537d3aab46e099475 added
jbd2_journal_file_inode() call into ext4_block_zero_page_range().
However that function gets called from truncate path and thus inode
needn't have jinode attached - that happens in ext4_file_open() but
the file needn't be ever open since mount. Calling
jbd2_journal_file_inode() without jinode attached results in the oops.

We fix the problem by attaching jinode to inode also in ext4_truncate()
and ext4_punch_hole() when we are going to zero out partial blocks.

Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 4 insertions, 17 deletions

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 6f4cc567c382..319c9d26279a 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -219,7 +219,6 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
 {
         struct super_block *sb = inode->i_sb;
         struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-        struct ext4_inode_info *ei = EXT4_I(inode);
         struct vfsmount *mnt = filp->f_path.mnt;
         struct path path;
         char buf[64], *cp;
@@ -259,22 +258,10 @@ static int ext4_file_open(struct inode * inode, struct file * filp)
          * Set up the jbd2_inode if we are opening the inode for
          * writing and the journal is present
          */
-        if (sbi->s_journal && !ei->jinode && (filp->f_mode & FMODE_WRITE)) {
-                struct jbd2_inode *jinode = jbd2_alloc_inode(GFP_KERNEL);
-
-                spin_lock(&inode->i_lock);
-                if (!ei->jinode) {
-                        if (!jinode) {
-                                spin_unlock(&inode->i_lock);
-                                return -ENOMEM;
-                        }
-                        ei->jinode = jinode;
-                        jbd2_journal_init_jbd_inode(ei->jinode, inode);
-                        jinode = NULL;
-                }
-                spin_unlock(&inode->i_lock);
-                if (unlikely(jinode != NULL))
-                        jbd2_free_inode(jinode);
+        if (filp->f_mode & FMODE_WRITE) {
+                int ret = ext4_inode_attach_jinode(inode);
+                if (ret < 0)
+                        return ret;
         }
         return dquot_file_open(inode, filp);
 }