On 13/12/2022 02:02, Jeff Layton wrote:

On Mon, 2022-12-12 at 18:56 +0100, Ilya Dryomov wrote:

...

On Fri, Nov 18, 2022 at 3:07 AM xiubli@redhat.com wrote:

...

From: Xiubo Li xiubli@redhat.com

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@vger.kernel.org Cc: Jeff Layton jlayton@kernel.org URL: https://tracker.ceph.com/issues/57986 Signed-off-by: Xiubo Li xiubli@redhat.com

---

fs/ceph/locks.c | 20 ++++++++++++++++++-- include/linux/ceph/ceph_fs_fl.h | 17 +++++++++++++++++ include/linux/fs.h | 2 ++ 3 files changed, 37 insertions(+), 2 deletions(-) create mode 100644 include/linux/ceph/ceph_fs_fl.h

diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c index b191426bf880..621f38f10a88 100644 --- a/fs/ceph/locks.c +++ b/fs/ceph/locks.c @@ -34,18 +34,34 @@ static void ceph_fl_copy_lock(struct file_lock *dst, struct file_lock *src) { struct inode *inode = file_inode(dst->fl_file); atomic_inc(&ceph_inode(inode)->i_filelock_ref);

•   dst->fl_u.ceph_fl.fl_inode = igrab(inode);
  

  }

+/*

• • Do not use the 'fl->fl_file' in release function, which
• • is possibly already released by another thread.
• */ static void ceph_fl_release_lock(struct file_lock *fl) {

•   struct inode *inode = file_inode(fl->fl_file);
  

•   struct ceph_inode_info *ci = ceph_inode(inode);
  

•   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);
     }
  

•   fl->fl_u.ceph_fl.fl_inode = NULL;
  

•   iput(inode);
  

  }

  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..ad1cf96329f9 --- /dev/null +++ b/include/linux/ceph/ceph_fs_fl.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/*

• • ceph_fs_fl.h - Ceph lock info
• • LGPL2
• */

+#ifndef CEPH_FS_FL_H +#define CEPH_FS_FL_H

+#include <linux/fs.h>

+struct ceph_lock_info {

•   struct inode *fl_inode;
  

+};

+#endif diff --git a/include/linux/fs.h b/include/linux/fs.h index d6cb42b7e91c..2b03d5e375d7 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;
  

Hi Xiubo and Jeff,

Xiubo, instead of defining struct ceph_lock_info and including a CephFS-specific header file in linux/fs.h, I think we should repeat what was done for AFS -- particularly given that ceph_lock_info ends up being a dummy type that isn't mentioned anywhere else.

Jeff, could you please ack this with your file locking hat on?

ACK. I think that would be cleaner.

Sure, will fix this.

Thanks,

- Xiubo

Thanks