From: aburford <andrew.burford@stonybrook.edu>
Date: Fri, 6 May 2022 15:44:36 +0000 (-0400)
Subject: add andrew-bugfix.patch
X-Git-Url: https://git.fsl.cs.sunysb.edu/?a=commitdiff_plain;h=cea418b8c3aa92bfc4629cc6a02e8509407e54dd;p=wrapfs-mgmt.git

add andrew-bugfix.patch
---

diff --git a/andrew-bugfix.patch b/andrew-bugfix.patch
new file mode 100644
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
+