From 487317c99477d00f22370625d53be3239febabbe Mon Sep 17 00:00:00 2001 From: Ronnie Sahlberg Date: Wed, 5 Jun 2019 10:38:38 +1000 Subject: cifs: add spinlock for the openFileList to cifsInodeInfo We can not depend on the tcon->open_file_lock here since in multiuser mode we may have the same file/inode open via multiple different tcons. The current code is race prone and will crash if one user deletes a file at the same time a different user opens/create the file. To avoid this we need to have a spinlock attached to the inode and not the tcon. RHBZ: 1580165 CC: Stable Signed-off-by: Ronnie Sahlberg Signed-off-by: Steve French Reviewed-by: Pavel Shilovsky --- fs/cifs/cifsglob.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'fs/cifs/cifsglob.h') diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 334ff5f9c3f3..4777b3c4a92c 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -1377,6 +1377,7 @@ struct cifsInodeInfo { struct rw_semaphore lock_sem; /* protect the fields above */ /* BB add in lists for dirty pages i.e. write caching info for oplock */ struct list_head openFileList; + spinlock_t open_file_lock; /* protects openFileList */ __u32 cifsAttrs; /* e.g. DOS archive bit, sparse, compressed, system */ unsigned int oplock; /* oplock/lease level we have */ unsigned int epoch; /* used to track lease state changes */ @@ -1780,10 +1781,14 @@ require use of the stronger protocol */ * tcp_ses_lock protects: * list operations on tcp and SMB session lists * tcon->open_file_lock protects the list of open files hanging off the tcon + * inode->open_file_lock protects the openFileList hanging off the inode * cfile->file_info_lock protects counters and fields in cifs file struct * f_owner.lock protects certain per file struct operations * mapping->page_lock protects certain per page operations * + * Note that the cifs_tcon.open_file_lock should be taken before + * not after the cifsInodeInfo.open_file_lock + * * Semaphores * ---------- * sesSem operations on smb session -- cgit v1.2.3