diff mbox series

[v4,14/17] xfs: mount-api - add xfs_fc_free()

Message ID 157009839296.13858.9863401564865806171.stgit@fedora-28 (mailing list archive)
State Superseded, archived
Headers show
Series xfs: mount API patch series | expand

Commit Message

Ian Kent Oct. 3, 2019, 10:26 a.m. UTC
Add the fs_context_operations method .free that performs fs
context cleanup on context release.

Signed-off-by: Ian Kent <raven@themaw.net>
---
 fs/xfs/xfs_super.c |   26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

Comments

Brian Foster Oct. 7, 2019, 11:51 a.m. UTC | #1
On Thu, Oct 03, 2019 at 06:26:32PM +0800, Ian Kent wrote:
> Add the fs_context_operations method .free that performs fs
> context cleanup on context release.
> 
> Signed-off-by: Ian Kent <raven@themaw.net>
> ---
>  fs/xfs/xfs_super.c |   26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 06f650fb3a8c..4f2963ff9e06 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -2133,10 +2133,36 @@ static const struct super_operations xfs_super_operations = {
>  	.free_cached_objects	= xfs_fs_free_cached_objects,
>  };
>  
> +static void xfs_fc_free(struct fs_context *fc)
> +{
> +	struct xfs_fs_context	*ctx = fc->fs_private;
> +	struct xfs_mount	*mp = fc->s_fs_info;
> +
> +	/*
> +	 * When the mount context is initialized the private
> +	 * struct xfs_mount info (mp) is allocated and stored in
> +	 * the fs context along with the struct xfs_fs_context
> +	 * (ctx) mount context working working storage.
> +	 *

"working working storage" ?

> +	 * On super block allocation the mount info struct, mp,
> +	 * is moved into private super block info field ->s_fs_info
> +	 * of the newly allocated super block. But if an error occurs
> +	 * before this happens it's the responsibility of the fs
> +	 * context to release the mount info struct.
> +	 */

I like the comment here, but it seems it could be simplified. E.g:

	/*
	 * mp and ctx are stored in the fs_context when it is initialized. mp is
	 * transferred to the superblock on a successful mount, but if an error
	 * occurs before the transfer we have to free it here.
	 */

> +	if (mp) {
> +		kfree(mp->m_logname);
> +		kfree(mp->m_rtname);

Also, can we just call xfs_free_fsname() here to be safe/consisent? With
those nits fixed up, this seems fine to me.

Brian

> +		kfree(mp);
> +	}
> +	kfree(ctx);
> +}
> +
>  static const struct fs_context_operations xfs_context_ops = {
>  	.parse_param = xfs_parse_param,
>  	.get_tree    = xfs_get_tree,
>  	.reconfigure = xfs_reconfigure,
> +	.free        = xfs_fc_free,
>  };
>  
>  static struct file_system_type xfs_fs_type = {
>
Ian Kent Oct. 8, 2019, 12:35 a.m. UTC | #2
On Mon, 2019-10-07 at 07:51 -0400, Brian Foster wrote:
> On Thu, Oct 03, 2019 at 06:26:32PM +0800, Ian Kent wrote:
> > Add the fs_context_operations method .free that performs fs
> > context cleanup on context release.
> > 
> > Signed-off-by: Ian Kent <raven@themaw.net>
> > ---
> >  fs/xfs/xfs_super.c |   26 ++++++++++++++++++++++++++
> >  1 file changed, 26 insertions(+)
> > 
> > diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> > index 06f650fb3a8c..4f2963ff9e06 100644
> > --- a/fs/xfs/xfs_super.c
> > +++ b/fs/xfs/xfs_super.c
> > @@ -2133,10 +2133,36 @@ static const struct super_operations
> > xfs_super_operations = {
> >  	.free_cached_objects	= xfs_fs_free_cached_objects,
> >  };
> >  
> > +static void xfs_fc_free(struct fs_context *fc)
> > +{
> > +	struct xfs_fs_context	*ctx = fc->fs_private;
> > +	struct xfs_mount	*mp = fc->s_fs_info;
> > +
> > +	/*
> > +	 * When the mount context is initialized the private
> > +	 * struct xfs_mount info (mp) is allocated and stored in
> > +	 * the fs context along with the struct xfs_fs_context
> > +	 * (ctx) mount context working working storage.
> > +	 *
> 
> "working working storage" ?

Oops!

> 
> > +	 * On super block allocation the mount info struct, mp,
> > +	 * is moved into private super block info field ->s_fs_info
> > +	 * of the newly allocated super block. But if an error occurs
> > +	 * before this happens it's the responsibility of the fs
> > +	 * context to release the mount info struct.
> > +	 */
> 
> I like the comment here, but it seems it could be simplified. E.g:
> 
> 	/*
> 	 * mp and ctx are stored in the fs_context when it is
> initialized. mp is
> 	 * transferred to the superblock on a successful mount, but if
> an error
> 	 * occurs before the transfer we have to free it here.
> 	 */

I like this, I'll use it thanks.

> 
> > +	if (mp) {
> > +		kfree(mp->m_logname);
> > +		kfree(mp->m_rtname);
> 
> Also, can we just call xfs_free_fsname() here to be safe/consisent?
> With
> those nits fixed up, this seems fine to me.

I think so, I'll check.

> 
> Brian
> 
> > +		kfree(mp);
> > +	}
> > +	kfree(ctx);
> > +}
> > +
> >  static const struct fs_context_operations xfs_context_ops = {
> >  	.parse_param = xfs_parse_param,
> >  	.get_tree    = xfs_get_tree,
> >  	.reconfigure = xfs_reconfigure,
> > +	.free        = xfs_fc_free,
> >  };
> >  
> >  static struct file_system_type xfs_fs_type = {
> >
diff mbox series

Patch

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 06f650fb3a8c..4f2963ff9e06 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -2133,10 +2133,36 @@  static const struct super_operations xfs_super_operations = {
 	.free_cached_objects	= xfs_fs_free_cached_objects,
 };
 
+static void xfs_fc_free(struct fs_context *fc)
+{
+	struct xfs_fs_context	*ctx = fc->fs_private;
+	struct xfs_mount	*mp = fc->s_fs_info;
+
+	/*
+	 * When the mount context is initialized the private
+	 * struct xfs_mount info (mp) is allocated and stored in
+	 * the fs context along with the struct xfs_fs_context
+	 * (ctx) mount context working working storage.
+	 *
+	 * On super block allocation the mount info struct, mp,
+	 * is moved into private super block info field ->s_fs_info
+	 * of the newly allocated super block. But if an error occurs
+	 * before this happens it's the responsibility of the fs
+	 * context to release the mount info struct.
+	 */
+	if (mp) {
+		kfree(mp->m_logname);
+		kfree(mp->m_rtname);
+		kfree(mp);
+	}
+	kfree(ctx);
+}
+
 static const struct fs_context_operations xfs_context_ops = {
 	.parse_param = xfs_parse_param,
 	.get_tree    = xfs_get_tree,
 	.reconfigure = xfs_reconfigure,
+	.free        = xfs_fc_free,
 };
 
 static struct file_system_type xfs_fs_type = {