Re: [PATCH 5/5] efivarfs: efivarfs_fill_super() ensure we clean up correctly on error

[Jeremy Kerr]

Hi Andy,


If we break out of the loop on the second (and onwards) iteration,
won't we still have the other inodes and dentries remaining
allocated?


As we calling this from the mount_single() wrapper:

 return mount_single(fs_type, flags, data, efivarfs_fill_super);


which does this:

 struct dentry *mount_single(struct file_system_type *fs_type,
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int))
 {
 [...]
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
deactivate_locked_super(s);
return ERR_PTR(error);
}
 [...]

I am expecting us to get called back via deactivate_locked_super(),
which calls sb->kill_sb() which is:

 static void efivarfs_kill_sb(struct super_block *sb)
 {
kill_litter_super(sb);
efivarfs_sb = NULL;
 }

Which I believe will clean them up.


Awesome, thanks for that. Looks good to me.

Acked-by: Jeremy Kerr 

Cheers,


Jeremy Kerr

--
To unsubscribe from this list: send the line "unsubscribe linux-efi" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 5/5] efivarfs: efivarfs_fill_super() ensure we clean up correctly on error

[Jeremy Kerr]

Hi Andy,


If we break out of the loop on the second (and onwards) iteration,
won't we still have the other inodes and dentries remaining
allocated?


As we calling this from the mount_single() wrapper:

 return mount_single(fs_type, flags, data, efivarfs_fill_super);


which does this:

 struct dentry *mount_single(struct file_system_type *fs_type,
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int))
 {
 [...]
error = fill_super(s, data, flags  MS_SILENT ? 1 : 0);
if (error) {
deactivate_locked_super(s);
return ERR_PTR(error);
}
 [...]

I am expecting us to get called back via deactivate_locked_super(),
which calls sb-kill_sb() which is:

 static void efivarfs_kill_sb(struct super_block *sb)
 {
kill_litter_super(sb);
efivarfs_sb = NULL;
 }

Which I believe will clean them up.


Awesome, thanks for that. Looks good to me.

Acked-by: Jeremy Kerr jeremy.k...@canonical.com

Cheers,


Jeremy Kerr

--
To unsubscribe from this list: send the line unsubscribe linux-efi in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 5/5] efivarfs: efivarfs_fill_super() ensure we clean up correctly on error

[Andy Whitcroft]

On Thu, Oct 11, 2012 at 10:04:28PM +0800, Jeremy Kerr wrote:
> Hi Andy,
> 
> >@@ -969,16 +970,18 @@
> > return -ENOMEM;
> >
> > list_for_each_entry_safe(entry, n, >list, list) {
> >-struct inode *inode;
> > struct dentry *dentry, *root = efivarfs_sb->s_root;
> >-char *name;
> > unsigned long size = 0;
> > int len, i;
> >
> >+inode = NULL;
> >+
> > len = utf16_strlen(entry->var.VariableName);
> >
> > /* GUID plus trailing NULL */
> > name = kmalloc(len + 38, GFP_ATOMIC);
> >+if (!name)
> >+goto fail;
> >
> > for (i = 0; i < len; i++)
> > name[i] = entry->var.VariableName[i] & 0xFF;
> >@@ -991,7 +994,13 @@
> >
> > inode = efivarfs_get_inode(efivarfs_sb, root->d_inode,
> >   S_IFREG | 0644, 0);
> >+if (!inode)
> >+goto fail_name;
> >+
> > dentry = d_alloc_name(root, name);
> >+if (!dentry)
> >+goto fail_inode;
> >+
> > /* copied by the above to local storage in the dentry. */
> > kfree(name);
> 
> If we break out of the loop on the second (and onwards) iteration,
> won't we still have the other inodes and dentries remaining
> allocated?

As we calling this from the mount_single() wrapper:

return mount_single(fs_type, flags, data, efivarfs_fill_super);


which does this:

struct dentry *mount_single(struct file_system_type *fs_type,
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int))
{
[...]
error = fill_super(s, data, flags & MS_SILENT ? 1 : 0);
if (error) {
deactivate_locked_super(s);
return ERR_PTR(error);
}
[...]

I am expecting us to get called back via deactivate_locked_super(),
which calls sb->kill_sb() which is:

static void efivarfs_kill_sb(struct super_block *sb)
{   
kill_litter_super(sb);
efivarfs_sb = NULL;
}   

Which I believe will clean them up.

-apw

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Re: [PATCH 5/5] efivarfs: efivarfs_fill_super() ensure we clean up correctly on error

[Jeremy Kerr]

Hi Andy,


@@ -969,16 +970,18 @@
return -ENOMEM;

list_for_each_entry_safe(entry, n, >list, list) {
-   struct inode *inode;
struct dentry *dentry, *root = efivarfs_sb->s_root;
-   char *name;
unsigned long size = 0;
int len, i;

+   inode = NULL;
+
len = utf16_strlen(entry->var.VariableName);

/* GUID plus trailing NULL */
name = kmalloc(len + 38, GFP_ATOMIC);
+   if (!name)
+   goto fail;

for (i = 0; i < len; i++)
name[i] = entry->var.VariableName[i] & 0xFF;
@@ -991,7 +994,13 @@

inode = efivarfs_get_inode(efivarfs_sb, root->d_inode,
  S_IFREG | 0644, 0);
+   if (!inode)
+   goto fail_name;
+   
dentry = d_alloc_name(root, name);
+   if (!dentry)
+   goto fail_inode;
+
/* copied by the above to local storage in the dentry. */
kfree(name);


If we break out of the loop on the second (and onwards) iteration, won't 
we still have the other inodes and dentries remaining allocated?


Cheers,


Jeremy

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Re: [PATCH 5/5] efivarfs: efivarfs_fill_super() ensure we clean up correctly on error

[Jeremy Kerr]

Hi Andy,


@@ -969,16 +970,18 @@
return -ENOMEM;

list_for_each_entry_safe(entry, n, efivars-list, list) {
-   struct inode *inode;
struct dentry *dentry, *root = efivarfs_sb-s_root;
-   char *name;
unsigned long size = 0;
int len, i;

+   inode = NULL;
+
len = utf16_strlen(entry-var.VariableName);

/* GUID plus trailing NULL */
name = kmalloc(len + 38, GFP_ATOMIC);
+   if (!name)
+   goto fail;

for (i = 0; i  len; i++)
name[i] = entry-var.VariableName[i]  0xFF;
@@ -991,7 +994,13 @@

inode = efivarfs_get_inode(efivarfs_sb, root-d_inode,
  S_IFREG | 0644, 0);
+   if (!inode)
+   goto fail_name;
+   
dentry = d_alloc_name(root, name);
+   if (!dentry)
+   goto fail_inode;
+
/* copied by the above to local storage in the dentry. */
kfree(name);


If we break out of the loop on the second (and onwards) iteration, won't 
we still have the other inodes and dentries remaining allocated?


Cheers,


Jeremy

--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Re: [PATCH 5/5] efivarfs: efivarfs_fill_super() ensure we clean up correctly on error

[Andy Whitcroft]

On Thu, Oct 11, 2012 at 10:04:28PM +0800, Jeremy Kerr wrote:
 Hi Andy,
 
 @@ -969,16 +970,18 @@
  return -ENOMEM;
 
  list_for_each_entry_safe(entry, n, efivars-list, list) {
 -struct inode *inode;
  struct dentry *dentry, *root = efivarfs_sb-s_root;
 -char *name;
  unsigned long size = 0;
  int len, i;
 
 +inode = NULL;
 +
  len = utf16_strlen(entry-var.VariableName);
 
  /* GUID plus trailing NULL */
  name = kmalloc(len + 38, GFP_ATOMIC);
 +if (!name)
 +goto fail;
 
  for (i = 0; i  len; i++)
  name[i] = entry-var.VariableName[i]  0xFF;
 @@ -991,7 +994,13 @@
 
  inode = efivarfs_get_inode(efivarfs_sb, root-d_inode,
S_IFREG | 0644, 0);
 +if (!inode)
 +goto fail_name;
 +
  dentry = d_alloc_name(root, name);
 +if (!dentry)
 +goto fail_inode;
 +
  /* copied by the above to local storage in the dentry. */
  kfree(name);
 
 If we break out of the loop on the second (and onwards) iteration,
 won't we still have the other inodes and dentries remaining
 allocated?

As we calling this from the mount_single() wrapper:

return mount_single(fs_type, flags, data, efivarfs_fill_super);


which does this:

struct dentry *mount_single(struct file_system_type *fs_type,
int flags, void *data,
int (*fill_super)(struct super_block *, void *, int))
{
[...]
error = fill_super(s, data, flags  MS_SILENT ? 1 : 0);
if (error) {
deactivate_locked_super(s);
return ERR_PTR(error);
}
[...]

I am expecting us to get called back via deactivate_locked_super(),
which calls sb-kill_sb() which is:

static void efivarfs_kill_sb(struct super_block *sb)
{   
kill_litter_super(sb);
efivarfs_sb = NULL;
}   

Which I believe will clean them up.

-apw

--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/