ocfs2: avoid inode removal while nfsd is accessing it

Patch series "ocfs2: fix nfsd over ocfs2 issues", v2.

This is a series of patches to fix issues on nfsd over ocfs2.  patch 1
is to avoid inode removed while nfsd access it patch 2 & 3 is to fix a
panic issue.

This patch (of 4):

When nfsd is getting file dentry using handle or parent dentry of some
dentry, one cluster lock is used to avoid inode removed from other node,
but it still could be removed from local node, so use a rw lock to avoid
this.

Link: http://lkml.kernel.org/r/20200616183829.87211-1-junxiao.bi@oracle.com
Link: http://lkml.kernel.org/r/20200616183829.87211-2-junxiao.bi@oracle.com
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 152a0fc4e9051411c8ced645e7abb9637a774a0a..751bc4dc74663933c09cec60c1c0dfeebc8e2888 100644 (file)
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -689,6 +689,12 @@ static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res,
                                   &ocfs2_nfs_sync_lops, osb);
 }
 
+static void ocfs2_nfs_sync_lock_init(struct ocfs2_super *osb)
+{
+       ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb);
+       init_rwsem(&osb->nfs_sync_rwlock);
+}
+
 void ocfs2_trim_fs_lock_res_init(struct ocfs2_super *osb)
 {
        struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres;
@@ -2855,6 +2861,11 @@ int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex)
        if (ocfs2_is_hard_readonly(osb))
                return -EROFS;
 
+       if (ex)
+               down_write(&osb->nfs_sync_rwlock);
+       else
+               down_read(&osb->nfs_sync_rwlock);
+
        if (ocfs2_mount_local(osb))
                return 0;
 
@@ -2873,6 +2884,10 @@ void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex)
        if (!ocfs2_mount_local(osb))
                ocfs2_cluster_unlock(osb, lockres,
                                     ex ? LKM_EXMODE : LKM_PRMODE);
+       if (ex)
+               up_write(&osb->nfs_sync_rwlock);
+       else
+               up_read(&osb->nfs_sync_rwlock);
 }
 
 int ocfs2_trim_fs_lock(struct ocfs2_super *osb,
@@ -3340,7 +3355,7 @@ int ocfs2_dlm_init(struct ocfs2_super *osb)
 local:
        ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
        ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
-       ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb);
+       ocfs2_nfs_sync_lock_init(osb);
        ocfs2_orphan_scan_lock_res_init(&osb->osb_orphan_scan.os_lockres, osb);
 
        osb->cconn = conn;

diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index ee5d985162125342fcc2e025b2a921e7176d9b48..2dd71d626196d9960c17f908cd3f9894db985de1 100644 (file)
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -395,6 +395,7 @@ struct ocfs2_super
        struct ocfs2_lock_res osb_super_lockres;
        struct ocfs2_lock_res osb_rename_lockres;
        struct ocfs2_lock_res osb_nfs_sync_lockres;
+       struct rw_semaphore nfs_sync_rwlock;
        struct ocfs2_lock_res osb_trim_fs_lockres;
        struct mutex obs_trim_fs_mutex;
        struct ocfs2_dlm_debug *osb_dlm_debug;