When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. Fix this up to be much
simpler logic and only create the root debugfs directory once when the
driver is first accessed. That resolves the memory leak and makes
things more obvious as to what the intent is.
Cc: Tudor Ambarus <[email protected]>
Cc: Pratyush Yadav <[email protected]>
Cc: Michael Walle <[email protected]>
Cc: Miquel Raynal <[email protected]>
Cc: Richard Weinberger <[email protected]>
Cc: Vignesh Raghavendra <[email protected]>
Cc: [email protected]
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/mtd/spi-nor/debugfs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/spi-nor/debugfs.c b/drivers/mtd/spi-nor/debugfs.c
index df76cb5de3f9..3aab595e82d1 100644
--- a/drivers/mtd/spi-nor/debugfs.c
+++ b/drivers/mtd/spi-nor/debugfs.c
@@ -228,11 +228,11 @@ static void spi_nor_debugfs_unregister(void *data)
void spi_nor_debugfs_register(struct spi_nor *nor)
{
- struct dentry *rootdir, *d;
+ static struct dentry *rootdir;
+ struct dentry *d;
int ret;
/* Create rootdir once. Will never be deleted again. */
- rootdir = debugfs_lookup(SPI_NOR_DEBUGFS_ROOT, NULL);
if (!rootdir)
rootdir = debugfs_create_dir(SPI_NOR_DEBUGFS_ROOT, NULL);
--
2.37.3
Hi,
Am 2022-09-02 15:37, schrieb Greg Kroah-Hartman:
> When calling debugfs_lookup() the result must have dput() called on it,
> otherwise the memory will leak over time. Fix this up to be much
> simpler logic and only create the root debugfs directory once when the
> driver is first accessed. That resolves the memory leak and makes
> things more obvious as to what the intent is.
>
> Cc: Tudor Ambarus <[email protected]>
> Cc: Pratyush Yadav <[email protected]>
> Cc: Michael Walle <[email protected]>
> Cc: Miquel Raynal <[email protected]>
> Cc: Richard Weinberger <[email protected]>
> Cc: Vignesh Raghavendra <[email protected]>
> Cc: [email protected]
> Cc: stable <[email protected]>
> Signed-off-by: Greg Kroah-Hartman <[email protected]>
> ---
> drivers/mtd/spi-nor/debugfs.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mtd/spi-nor/debugfs.c
> b/drivers/mtd/spi-nor/debugfs.c
> index df76cb5de3f9..3aab595e82d1 100644
> --- a/drivers/mtd/spi-nor/debugfs.c
> +++ b/drivers/mtd/spi-nor/debugfs.c
> @@ -228,11 +228,11 @@ static void spi_nor_debugfs_unregister(void
> *data)
>
> void spi_nor_debugfs_register(struct spi_nor *nor)
> {
> - struct dentry *rootdir, *d;
> + static struct dentry *rootdir;
> + struct dentry *d;
> int ret;
>
> /* Create rootdir once. Will never be deleted again. */
> - rootdir = debugfs_lookup(SPI_NOR_DEBUGFS_ROOT, NULL);
IIRC I had that one and it didn't work with spi-nor as a module.
Wouldn't it try to create the root dir twice if you remove the module
and load it again?
-michael
> if (!rootdir)
> rootdir = debugfs_create_dir(SPI_NOR_DEBUGFS_ROOT, NULL);
On Fri, Sep 02, 2022 at 04:01:36PM +0200, Michael Walle wrote:
> Hi,
>
> Am 2022-09-02 15:37, schrieb Greg Kroah-Hartman:
> > When calling debugfs_lookup() the result must have dput() called on it,
> > otherwise the memory will leak over time. Fix this up to be much
> > simpler logic and only create the root debugfs directory once when the
> > driver is first accessed. That resolves the memory leak and makes
> > things more obvious as to what the intent is.
> >
> > Cc: Tudor Ambarus <[email protected]>
> > Cc: Pratyush Yadav <[email protected]>
> > Cc: Michael Walle <[email protected]>
> > Cc: Miquel Raynal <[email protected]>
> > Cc: Richard Weinberger <[email protected]>
> > Cc: Vignesh Raghavendra <[email protected]>
> > Cc: [email protected]
> > Cc: stable <[email protected]>
> > Signed-off-by: Greg Kroah-Hartman <[email protected]>
> > ---
> > drivers/mtd/spi-nor/debugfs.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mtd/spi-nor/debugfs.c
> > b/drivers/mtd/spi-nor/debugfs.c
> > index df76cb5de3f9..3aab595e82d1 100644
> > --- a/drivers/mtd/spi-nor/debugfs.c
> > +++ b/drivers/mtd/spi-nor/debugfs.c
> > @@ -228,11 +228,11 @@ static void spi_nor_debugfs_unregister(void *data)
> >
> > void spi_nor_debugfs_register(struct spi_nor *nor)
> > {
> > - struct dentry *rootdir, *d;
> > + static struct dentry *rootdir;
> > + struct dentry *d;
> > int ret;
> >
> > /* Create rootdir once. Will never be deleted again. */
> > - rootdir = debugfs_lookup(SPI_NOR_DEBUGFS_ROOT, NULL);
>
> IIRC I had that one and it didn't work with spi-nor as a module.
> Wouldn't it try to create the root dir twice if you remove the module
> and load it again?
Yes it would, that is a use-model I did not consider at all, thanks.
I'll rework this.
greg k-h
On Sat, Sep 24, 2022 at 10:46:22AM +0200, Greg Kroah-Hartman wrote:
> On Fri, Sep 02, 2022 at 04:01:36PM +0200, Michael Walle wrote:
> > Hi,
> >
> > Am 2022-09-02 15:37, schrieb Greg Kroah-Hartman:
> > > When calling debugfs_lookup() the result must have dput() called on it,
> > > otherwise the memory will leak over time. Fix this up to be much
> > > simpler logic and only create the root debugfs directory once when the
> > > driver is first accessed. That resolves the memory leak and makes
> > > things more obvious as to what the intent is.
> > >
> > > Cc: Tudor Ambarus <[email protected]>
> > > Cc: Pratyush Yadav <[email protected]>
> > > Cc: Michael Walle <[email protected]>
> > > Cc: Miquel Raynal <[email protected]>
> > > Cc: Richard Weinberger <[email protected]>
> > > Cc: Vignesh Raghavendra <[email protected]>
> > > Cc: [email protected]
> > > Cc: stable <[email protected]>
> > > Signed-off-by: Greg Kroah-Hartman <[email protected]>
> > > ---
> > > drivers/mtd/spi-nor/debugfs.c | 4 ++--
> > > 1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/mtd/spi-nor/debugfs.c
> > > b/drivers/mtd/spi-nor/debugfs.c
> > > index df76cb5de3f9..3aab595e82d1 100644
> > > --- a/drivers/mtd/spi-nor/debugfs.c
> > > +++ b/drivers/mtd/spi-nor/debugfs.c
> > > @@ -228,11 +228,11 @@ static void spi_nor_debugfs_unregister(void *data)
> > >
> > > void spi_nor_debugfs_register(struct spi_nor *nor)
> > > {
> > > - struct dentry *rootdir, *d;
> > > + static struct dentry *rootdir;
> > > + struct dentry *d;
> > > int ret;
> > >
> > > /* Create rootdir once. Will never be deleted again. */
> > > - rootdir = debugfs_lookup(SPI_NOR_DEBUGFS_ROOT, NULL);
> >
> > IIRC I had that one and it didn't work with spi-nor as a module.
> > Wouldn't it try to create the root dir twice if you remove the module
> > and load it again?
>
> Yes it would, that is a use-model I did not consider at all, thanks.
> I'll rework this.
v2 with this fixed up now sent, thanks.
greg k-h