add andrew-bugfix.patch

diff --git a/andrew-bugfix.patch b/andrew-bugfix.patch
new file mode 100644 (file)
index 0000000..89c5355
--- /dev/null
+++ b/andrew-bugfix.patch
@@ -0,0 +1,139 @@
+From 7bdf1ffeeda07fd960783e56449dd057d3cd2781 Mon Sep 17 00:00:00 2001
+From: aburford <andrew.burford@stonybrook.edu>
+Date: Thu, 28 Apr 2022 16:03:46 -0400
+Subject: [PATCH 1/2] fix error handling in wrapfs_read_super
+
+---
+ fs/wrapfs/dentry.c |  8 +++++---
+ fs/wrapfs/main.c   | 20 +++++---------------
+ 2 files changed, 10 insertions(+), 18 deletions(-)
+
+diff --git a/fs/wrapfs/dentry.c b/fs/wrapfs/dentry.c
+index d17d063..507dce4 100644
+--- a/fs/wrapfs/dentry.c
++++ b/fs/wrapfs/dentry.c
+@@ -34,9 +34,11 @@ static int wrapfs_d_revalidate(struct dentry *dentry, unsigned int flags)
+ 
+ static void wrapfs_d_release(struct dentry *dentry)
+ {
+-      /* release and reset the lower paths */
+-      wrapfs_put_reset_lower_path(dentry);
+-      free_dentry_private_data(dentry);
++      if (WRAPFS_D(dentry)) {
++              /* release and reset the lower paths */
++              wrapfs_put_reset_lower_path(dentry);
++              free_dentry_private_data(dentry);
++      }
+       return;
+ }
+ 
+diff --git a/fs/wrapfs/main.c b/fs/wrapfs/main.c
+index daf1758..f0cbf30 100644
+--- a/fs/wrapfs/main.c
++++ b/fs/wrapfs/main.c
+@@ -42,7 +42,7 @@ static int wrapfs_read_super(struct super_block *sb, void *raw_data, int silent)
+       if (!WRAPFS_SB(sb)) {
+               printk(KERN_CRIT "wrapfs: read_super: out of memory\n");
+               err = -ENOMEM;
+-              goto out_free;
++              goto out_pput;
+       }
+ 
+       /* set the lower superblock field of upper superblock */
+@@ -68,12 +68,12 @@ static int wrapfs_read_super(struct super_block *sb, void *raw_data, int silent)
+       inode = wrapfs_iget(sb, d_inode(lower_path.dentry));
+       if (IS_ERR(inode)) {
+               err = PTR_ERR(inode);
+-              goto out_sput;
++              goto out_pput;
+       }
+       sb->s_root = d_make_root(inode);
+       if (!sb->s_root) {
+               err = -ENOMEM;
+-              goto out_iput;
++              goto out_pput;
+       }
+       d_set_d_op(sb->s_root, &wrapfs_dops);
+ 
+@@ -81,7 +81,7 @@ static int wrapfs_read_super(struct super_block *sb, void *raw_data, int silent)
+       sb->s_root->d_fsdata = NULL;
+       err = new_dentry_private_data(sb->s_root);
+       if (err)
+-              goto out_freeroot;
++              goto out_pput;
+ 
+       /* if get here: cannot have error */
+ 
+@@ -101,18 +101,8 @@ static int wrapfs_read_super(struct super_block *sb, void *raw_data, int silent)
+       goto out; /* all is well */
+ 
+       /* no longer needed: free_dentry_private_data(sb->s_root); */
+-out_freeroot:
+-      dput(sb->s_root);
+-out_iput:
+-      iput(inode);
+-out_sput:
+-      /* drop refs we took earlier */
+-      atomic_dec(&lower_sb->s_active);
+-      kfree(WRAPFS_SB(sb));
+-      sb->s_fs_info = NULL;
+-out_free:
++out_pput:
+       path_put(&lower_path);
+-
+ out:
+       return err;
+ }
+-- 
+2.7.4
+
+
+From e225135ad17e5f257c9b1eea16c55066db1a335a Mon Sep 17 00:00:00 2001
+From: aburford <andrew.burford@stonybrook.edu>
+Date: Mon, 2 May 2022 10:57:56 -0400
+Subject: [PATCH 2/2] add clarifying comments
+
+---
+ fs/wrapfs/dentry.c | 6 ++++++
+ fs/wrapfs/main.c   | 8 +++++++-
+ 2 files changed, 13 insertions(+), 1 deletion(-)
+
+diff --git a/fs/wrapfs/dentry.c b/fs/wrapfs/dentry.c
+index 507dce4..dc7e6e6 100644
+--- a/fs/wrapfs/dentry.c
++++ b/fs/wrapfs/dentry.c
+@@ -34,6 +34,12 @@ static int wrapfs_d_revalidate(struct dentry *dentry, unsigned int flags)
+ 
+ static void wrapfs_d_release(struct dentry *dentry)
+ {
++      /*
++       * It is possible that the dentry private data is null
++       * incase we ran out of memory while initializing it in
++       * new_dentry_private_data. So check for NULL before
++       * attempting to release resources
++       */
+       if (WRAPFS_D(dentry)) {
+               /* release and reset the lower paths */
+               wrapfs_put_reset_lower_path(dentry);
+diff --git a/fs/wrapfs/main.c b/fs/wrapfs/main.c
+index f0cbf30..bb14ac3 100644
+--- a/fs/wrapfs/main.c
++++ b/fs/wrapfs/main.c
+@@ -100,7 +100,13 @@ static int wrapfs_read_super(struct super_block *sb, void *raw_data, int silent)
+                      dev_name, lower_sb->s_type->name);
+       goto out; /* all is well */
+ 
+-      /* no longer needed: free_dentry_private_data(sb->s_root); */
++      /*
++       * path_put is the only resource we need to free if an error
++       * occured because returning an error from this function will
++       * cause generic_shutdown_super to be called which will call
++       * wrapfs_put_super and that function will release any other
++       * resources we took.
++       */
+ out_pput:
+       path_put(&lower_path);
+ out:
+-- 
+2.7.4
+