yaffsfs.c: Fix NULL dereference in yaffs_unmount2_reldev()

[yaffs2.git] / yaffs_vfs_single.c

diff --git a/yaffs_vfs_single.c b/yaffs_vfs_single.c
index 232dc2625328a7173509456dcf227c7411d9da5b..0817ff0c30399db41e0104f112226b9d2210175a 100644 (file)
--- a/yaffs_vfs_single.c
+++ b/yaffs_vfs_single.c
@@ -1,8 +1,7 @@
 /*
  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
  *
- * Copyright (C) 2002-2011 Aleph One Ltd.
- *   for Toby Churchill Ltd and Brightstar Engineering
+ * Copyright (C) 2002-2018 Aleph One Ltd.
  *
  * Created by Charles Manning <charles@aleph1.co.uk>
  * Acknowledgements:
@@ -450,7 +449,7 @@ static int yaffs_sync_object(struct file *file,
 
        yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC, "yaffs_sync_object");
        yaffs_gross_lock(dev);
-       yaffs_flush_file(obj, 1, datasync);
+       yaffs_flush_file(obj, 1, datasync, 0);
        yaffs_gross_unlock(dev);
        return 0;
 }
@@ -890,7 +889,7 @@ static int yaffs_file_flush(struct file *file, fl_owner_t id)
 
        yaffs_gross_lock(dev);
 
-       yaffs_flush_file(obj, 1, 0);
+       yaffs_flush_file(obj, 1, 0, 0);
 
        yaffs_gross_unlock(dev);
 
@@ -1490,15 +1489,34 @@ static void yaffs_flush_inodes(struct super_block *sb)
 {
        struct inode *iptr;
        struct yaffs_obj *obj;
+       struct yaffs_dev *dev = yaffs_super_to_dev(sb);
 
+       spin_lock(&sb->s_inode_list_lock);
        list_for_each_entry(iptr, &sb->s_inodes, i_sb_list) {
+               spin_lock(&inode->i_lock);
+               if (iptr->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) {
+                       spin_unlock(&inode->i_lock);
+                       continue;
+               }
+
+               __iget(iptr);
+               spin_unlock(&inode->i_lock);
+               spin_unlock(&sb->s_inode_list_lock);
+
                obj = yaffs_inode_to_obj(iptr);
                if (obj) {
                        yaffs_trace(YAFFS_TRACE_OS,
                                "flushing obj %d", obj->obj_id);
-                       yaffs_flush_file(obj, 1, 0);
+                       yaffs_flush_file(obj, 1, 0, 0);
                }
+
+               yaffs_gross_unlock(dev);
+               iput(iptr);
+               yaffs_gross_lock(dev);
+
+               spin_lock(&sb->s_inode_list_lock);
        }
+       spin_unlock(&sb->s_inode_list_lock);
 }
 
 static void yaffs_flush_super(struct super_block *sb, int do_checkpoint)
@@ -1510,7 +1528,7 @@ static void yaffs_flush_super(struct super_block *sb, int do_checkpoint)
 
        yaffs_flush_inodes(sb);
        yaffs_update_dirty_dirs(dev);
-       yaffs_flush_whole_cache(dev);
+       yaffs_flush_whole_cache(dev, 1);
        if (do_checkpoint)
                yaffs_checkpoint_save(dev);
 }
@@ -1872,11 +1890,11 @@ static void yaffs_fill_inode_from_obj(struct inode *inode,
 
        inode->i_rdev = old_decode_dev(obj->yst_rdev);
 
-       inode->i_atime.tv_sec = (time_t) (obj->yst_atime);
+       inode->i_atime.tv_sec = (YTIME_T) (obj->yst_atime);
        inode->i_atime.tv_nsec = 0;
-       inode->i_mtime.tv_sec = (time_t) obj->yst_mtime;
+       inode->i_mtime.tv_sec = (YTIME_T) obj->yst_mtime;
        inode->i_mtime.tv_nsec = 0;
-       inode->i_ctime.tv_sec = (time_t) obj->yst_ctime;
+       inode->i_ctime.tv_sec = (YTIME_T) obj->yst_ctime;
        inode->i_ctime.tv_nsec = 0;
        inode->i_size = yaffs_get_obj_length(obj);
        inode->i_blocks = (inode->i_size + 511) >> 9;
@@ -1943,8 +1961,6 @@ static void yaffs_put_super(struct super_block *sb)
 
        kfree(dev);
 
-
-
        if (mtd && mtd->sync)
                mtd->sync(mtd);
 
@@ -1952,12 +1968,54 @@ static void yaffs_put_super(struct super_block *sb)
                put_mtd_device(mtd);
 }
 
+/* the function only is used to change dev->read_only when this file system
+ * is remounted.
+ */
+static int yaffs_remount_fs(struct super_block *sb, int *flags, char *data)
+{
+       int read_only = 0;
+       struct mtd_info *mtd;
+       struct yaffs_dev *dev = 0;
+
+       /* Get the device */
+       mtd = get_mtd_device(NULL, MINOR(sb->s_dev));
+       if (!mtd) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "MTD device #%u doesn't appear to exist",
+                       MINOR(sb->s_dev));
+               return 1;
+       }
+
+       /* Check it's NAND */
+       if (mtd->type != MTD_NANDFLASH) {
+               yaffs_trace(YAFFS_TRACE_ALWAYS,
+                       "MTD device is not NAND it's type %d",
+                       mtd->type);
+               return 1;
+       }
+
+       read_only = ((*flags & MS_RDONLY) != 0);
+       if (!read_only && !(mtd->flags & MTD_WRITEABLE)) {
+               read_only = 1;
+               printk(KERN_INFO
+                       "yaffs: mtd is read only, setting superblock read only");
+               *flags |= MS_RDONLY;
+       }
+
+       dev = sb->s_fs_info;
+       dev->read_only = read_only;
+
+       return 0;
+}
+
+
 static const struct super_operations yaffs_super_ops = {
        .statfs = yaffs_statfs,
        .put_super = yaffs_put_super,
        .evict_inode = yaffs_evict_inode,
        .sync_fs = yaffs_sync_fs,
        .write_super = yaffs_write_super,
+       .remount_fs = yaffs_remount_fs,
 };
 
 static struct super_block *yaffs_internal_read_super(int yaffs_version,