Register .remount_fs handler

Register the missing .remount_fs handler.  This handler isn't strictly
required because the VFS does a pretty good job updating most of the
MS_* flags.  However, there's no harm in using the hook to call the
registered zpl callback for various MS_* flags.  Additionaly, this
allows us to lay the ground work for more complicated argument parsing
in the future.

diff --git a/include/sys/zfs_vfsops.h b/include/sys/zfs_vfsops.h
index a2f00ac..7622f03 100644 (file)
--- a/include/sys/zfs_vfsops.h
+++ b/include/sys/zfs_vfsops.h
@@ -187,6 +187,7 @@ extern int zfs_register_callbacks(zfs_sb_t *zsb);
 extern void zfs_unregister_callbacks(zfs_sb_t *zsb);
 extern int zfs_domount(struct super_block *sb, void *data, int silent);
 extern int zfs_umount(struct super_block *sb);
+extern int zfs_remount(struct super_block *sb, int *flags, char *data);
 extern int zfs_root(zfs_sb_t *zsb, struct inode **ipp);
 extern int zfs_statvfs(struct dentry *dentry, struct kstatfs *statp);
 extern int zfs_vget(struct vfsmount *vfsp, struct inode **ipp, fid_t *fidp);

diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c
index 1e8e6af..8036074 100644 (file)
--- a/module/zfs/zfs_vfsops.c
+++ b/module/zfs/zfs_vfsops.c
@@ -1292,6 +1292,46 @@ zfs_umount(struct super_block *sb)
 EXPORT_SYMBOL(zfs_umount);
 
 int
+zfs_remount(struct super_block *sb, int *flags, char *data)
+{
+       zfs_sb_t *zsb = sb->s_fs_info;
+       boolean_t readonly = B_FALSE;
+       boolean_t setuid = B_TRUE;
+       boolean_t exec = B_TRUE;
+       boolean_t devices = B_TRUE;
+       boolean_t atime = B_TRUE;
+
+       if (*flags & MS_RDONLY)
+               readonly = B_TRUE;
+
+       if (*flags & MS_NOSUID) {
+               devices = B_FALSE;
+               setuid = B_FALSE;
+       } else {
+               if (*flags & MS_NODEV)
+                       devices = B_FALSE;
+       }
+
+       if (*flags & MS_NOEXEC)
+               exec = B_FALSE;
+
+       if (*flags & MS_NOATIME)
+               atime = B_FALSE;
+
+       /*
+        * Invoke our callbacks to set required flags.
+        */
+       readonly_changed_cb(zsb, readonly);
+       setuid_changed_cb(zsb, setuid);
+       exec_changed_cb(zsb, exec);
+       devices_changed_cb(zsb, devices);
+       atime_changed_cb(zsb, atime);
+
+       return (0);
+}
+EXPORT_SYMBOL(zfs_remount);
+
+int
 zfs_vget(struct vfsmount *vfsp, struct inode **ipp, fid_t *fidp)
 {
        zfs_sb_t        *zsb = VTOZSB(vfsp);

diff --git a/module/zfs/zpl_super.c b/module/zfs/zpl_super.c
index 73e5268..6524a65 100644 (file)
--- a/module/zfs/zpl_super.c
+++ b/module/zfs/zpl_super.c
@@ -130,6 +130,16 @@ zpl_statfs(struct dentry *dentry, struct kstatfs *statp)
 }
 
 static int
+zpl_remount_fs(struct super_block *sb, int *flags, char *data)
+{
+       int error;
+       error = -zfs_remount(sb, flags, data);
+       ASSERT3S(error, <=, 0);
+
+       return (error);
+}
+
+static int
 zpl_show_options(struct seq_file *seq, struct vfsmount *vfsp)
 {
        struct super_block *sb = vfsp->mnt_sb;
@@ -197,7 +207,7 @@ const struct super_operations zpl_super_operations = {
        .freeze_fs      = NULL,
        .unfreeze_fs    = NULL,
        .statfs         = zpl_statfs,
-       .remount_fs     = NULL,
+       .remount_fs     = zpl_remount_fs,
        .show_options   = zpl_show_options,
        .show_stats     = NULL,
 };