On Mon, 2022-11-14 at 13:19 +0800, xiubli@xxxxxxxxxx wrote: > From: Xiubo Li <xiubli@xxxxxxxxxx> > > When ceph releasing the file_lock it will try to get the inode pointer > from the fl->fl_file, which the memory could already be released by > another thread in filp_close(). Because in VFS layer the fl->fl_file > doesn't increase the file's reference counter. > > Will switch to use ceph dedicate lock info to track the inode. > > And in ceph_fl_release_lock() we should skip all the operations if > the fl->fl_u.ceph_fl.fl_inode is not set, which should come from > the request file_lock. And we will set fl->fl_u.ceph_fl.fl_inode when > inserting it to the inode lock list, which is when copying the lock. > > Cc: stable@xxxxxxxxxxxxxxx > URL: https://tracker.ceph.com/issues/57986 > Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx> > --- > fs/ceph/locks.c | 18 +++++++++++++++--- > include/linux/ceph/ceph_fs_fl.h | 26 ++++++++++++++++++++++++++ > include/linux/fs.h | 2 ++ > 3 files changed, 43 insertions(+), 3 deletions(-) > create mode 100644 include/linux/ceph/ceph_fs_fl.h > > diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c > index 3e2843e86e27..d8385dd0076e 100644 > --- a/fs/ceph/locks.c > +++ b/fs/ceph/locks.c > @@ -34,22 +34,34 @@ static void ceph_fl_copy_lock(struct file_lock *dst, struct file_lock *src) > { > struct ceph_file_info *fi = dst->fl_file->private_data; > struct inode *inode = file_inode(dst->fl_file); > + > atomic_inc(&ceph_inode(inode)->i_filelock_ref); > atomic_inc(&fi->num_locks); > + dst->fl_u.ceph_fl.fl_inode = igrab(inode); > } > > static void ceph_fl_release_lock(struct file_lock *fl) > { > struct ceph_file_info *fi = fl->fl_file->private_data; > - struct inode *inode = file_inode(fl->fl_file); > - struct ceph_inode_info *ci = ceph_inode(inode); > - atomic_dec(&fi->num_locks); > + struct inode *inode = fl->fl_u.ceph_fl.fl_inode; > + struct ceph_inode_info *ci; > + > + /* > + * If inode is NULL it should be a request file_lock, > + * nothing we can do. > + */ > + if (!inode) > + return; > + > + ci = ceph_inode(inode); > if (atomic_dec_and_test(&ci->i_filelock_ref)) { > /* clear error when all locks are released */ > spin_lock(&ci->i_ceph_lock); > ci->i_ceph_flags &= ~CEPH_I_ERROR_FILELOCK; > spin_unlock(&ci->i_ceph_lock); > } > + iput(inode); > + atomic_dec(&fi->num_locks); It doesn't look like this fixes the original issue. "fi" may be pointing to freed memory at this point, right? I think you may need to get rid of the "num_locks" field in ceph_file_info, and do that in a different way? > } > > static const struct file_lock_operations ceph_fl_lock_ops = { > diff --git a/include/linux/ceph/ceph_fs_fl.h b/include/linux/ceph/ceph_fs_fl.h > new file mode 100644 > index 000000000000..02a412b26095 > --- /dev/null > +++ b/include/linux/ceph/ceph_fs_fl.h > @@ -0,0 +1,26 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * ceph_fs.h - Ceph constants and data types to share between kernel and > + * user space. > + * > + * Most types in this file are defined as little-endian, and are > + * primarily intended to describe data structures that pass over the > + * wire or that are stored on disk. > + * > + * LGPL2 > + */ > + > +#ifndef CEPH_FS_FL_H > +#define CEPH_FS_FL_H > + > +#include <linux/fs.h> > + > +/* > + * Ceph lock info > + */ > + > +struct ceph_lock_info { > + struct inode *fl_inode; > +}; > + > +#endif > diff --git a/include/linux/fs.h b/include/linux/fs.h > index e654435f1651..db4810d19e26 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -1066,6 +1066,7 @@ bool opens_in_grace(struct net *); > > /* that will die - we need it for nfs_lock_info */ > #include <linux/nfs_fs_i.h> > +#include <linux/ceph/ceph_fs_fl.h> > > /* > * struct file_lock represents a generic "file lock". It's used to represent > @@ -1119,6 +1120,7 @@ struct file_lock { > int state; /* state of grant or error if -ve */ > unsigned int debug_id; > } afs; > + struct ceph_lock_info ceph_fl; > } fl_u; > } __randomize_layout; > -- Jeff Layton <jlayton@xxxxxxxxxx>
