jfs_mount_rw can call diUnmount and then diMount. These calls change the
imap pointer. Between these two calls there may be calls of function
jfs_lookup(). The jfs_lookup() function calls jfs_iget(), which, in turn
calls diRead(). The latter references the imap pointer. That may cause
diRead() to refer to a pointer freed in diUnmount(). This commit makes
the calls to diUnmount()/diMount() atomic so that nothing will read the
imap pointer until the whole remount is completed.
Signed-off-by: Oleg Kanatov <okanatov@gmail.com>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
iagno = INOTOIAG(ip->i_ino);
/* read the iag */
- imap = JFS_IP(ipimap)->i_imap;
IREAD_LOCK(ipimap, RDWRLOCK_IMAP);
+ imap = JFS_IP(ipimap)->i_imap;
rc = diIAGRead(imap, iagno, &mp);
IREAD_UNLOCK(ipimap);
if (rc) {
truncate_inode_pages(sbi->ipimap->i_mapping, 0);
truncate_inode_pages(sbi->ipbmap->i_mapping, 0);
+
+ IWRITE_LOCK(sbi->ipimap, RDWRLOCK_IMAP);
diUnmount(sbi->ipimap, 1);
if ((rc = diMount(sbi->ipimap))) {
+ IWRITE_UNLOCK(sbi->ipimap);
jfs_err("jfs_mount_rw: diMount failed!");
return rc;
}
+ IWRITE_UNLOCK(sbi->ipimap);
dbUnmount(sbi->ipbmap, 1);
if ((rc = dbMount(sbi->ipbmap))) {