Documentation/DocBook/procfs* appears to confirm that THIS_MODULE is the
key.
Mark Studebaker wrote:
>
> Don't know - anybody?
>
> Alexander Viro wrote:
> >
> > On Thu, 5 Sep 2002, Mark D. Studebaker wrote:
> >
> > > removed from i2c-proc.c. As the comments say, the code prevents module
> > > unloading
> > > if the /proc files are in use.
> >
> > So does setting ->owner on them.
> >
> > > Why is this a bad thing?
> >
> > Because module has no business messing with its own reference count.
> >
> > > Is there a better way to do it?
> >
> > See above.
>
> Does Al mean we already do the right thing in i2c-dev.c:89
> static struct file_operations i2cdev_fops {
> owner: THIS_MODULE,
>
> and i2c-dev.c:495 int __init i2c_dev_init
> ...
> if (register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops))
>
> If so, we need to find a method to verify his statement.
> Oh, Linus applied the reverse patch for this to 2.5.34.
> Albert
> --
> Albert Cranford Deerfield Beach FL USA
> ac9410 at bellsouth.net
>
> ===============================================================================================================
>
>
>
> Subject: Re: i2c-proc correction
> Date: Thu, 05 Sep 2002 22:51:55 -0400
> From: "Mark D. Studebaker" <mds at paradyne.com>
> Organization: Paradyne Networks, Largo FL
> To: viro at math.psu.edu
> CC: Albert Cranford <ac9410 at attbi.com>
> References: <3D760B07.D1EFD4C8 at attbi.com>
>
> Al,
>
> Albert Cranford and I work on the lm_sensors project.
>
> in May 2002 you removed what was called
> "s390 procfs abuse" lines with i2c_fill_inode procedure in
> drivers/i2c/i2c-proc.c -
> kernel 2.5.18 -
>
> URL
>
> http://linux.bkbits.net:8080/linux-2.5/diffs/drivers/i2c/i2c-proc.c at 1.3?nav=index.html|src/.|src/drivers|src/drivers/i2c|hist/drivers/i2c/i2c-proc.c
>
> We inadvertently put the lines back into kernel 2.5.32 with our recent
> patch. Sorry.
> We are submitting a patch to Linus (below) to take them back out in
> kernel 2.5.34.
>
> However, I don't understand what 's390 procfs abuse' is or why these
> lines were
> removed from i2c-proc.c. As the comments say, the code prevents module
> unloading
> if the /proc files are in use. Why is this a bad thing? Is there a
> better way to do it?
>
> Thank you very much for your help.
>
> mds
>
> > --- linux-2.5.33/drivers/i2c/i2c-proc.c.orig 2002-09-04 09:04:30.000000000 -0400
> > +++ linux/drivers/i2c/i2c-proc.c 2002-09-04 09:08:59.000000000 -0400
> > @@ -60,7 +60,6 @@
> > static struct ctl_table_header *i2c_entries[SENSORS_ENTRY_MAX];
> >
> > static struct i2c_client *i2c_clients[SENSORS_ENTRY_MAX];
> > -static unsigned short i2c_inodes[SENSORS_ENTRY_MAX];
> >
> > static ctl_table sysctl_table[] = {
> > {CTL_DEV, "dev", NULL, 0, 0555},
> > @@ -189,8 +188,6 @@
> > return id;
> > }
> > #endif /* DEBUG */
> > - i2c_inodes[id - 256] =
> > - new_header->ctl_table->child->child->de->low_ino;
> > new_header->ctl_table->child->child->de->owner = controlling_mod;
> >
> > return id;
> > @@ -213,49 +210,6 @@
> > }
> > }
> >
> > -/* Monitor access for /proc/sys/dev/sensors; make unloading i2c-proc.o
> > - impossible if some process still uses it or some file in it */
> > -void i2c_fill_inode(struct inode *inode, int fill)
> > -{
> > - if (fill)
> > - MOD_INC_USE_COUNT;
> > - else
> > - MOD_DEC_USE_COUNT;
> > -}
> > -
> > -/* Monitor access for /proc/sys/dev/sensors/ directories; make unloading
> > - the corresponding module impossible if some process still uses it or
> > - some file in it */
> > -void i2c_dir_fill_inode(struct inode *inode, int fill)
> > -{
> > - int i;
> > - struct i2c_client *client;
> > -
> > -#ifdef DEBUG
> > - if (!inode) {
> > - printk(KERN_ERR "i2c-proc.o: Warning: inode NULL in fill_inode()\n");
> > - return;
> > - }
> > -#endif /* def DEBUG */
> > -
> > - for (i = 0; i < SENSORS_ENTRY_MAX; i++)
> > - if (i2c_clients[i]
> > - && (i2c_inodes[i] == inode->i_ino)) break;
> > -#ifdef DEBUG
> > - if (i == SENSORS_ENTRY_MAX) {
> > - printk
> > - (KERN_ERR "i2c-proc.o: Warning: inode (%ld) not found in fill_inode()\n",
> > - inode->i_ino);
> > - return;
> > - }
> > -#endif /* def DEBUG */
> > - client = i2c_clients[i];
> > - if (fill)
> > - client->driver->inc_use(client);
> > - else
> > - client->driver->dec_use(client);
> > -}
> > -
> > int i2c_proc_chips(ctl_table * ctl, int write, struct file *filp,
> > void *buffer, size_t * lenp)
> > {
> >
