Very Computer

by **Greg K** » Fri, 02 Aug 2002 03:40:08

Hi,

First off, I've added one more small patch to this series, that removes
all of the devfs_should* functions that I created, with a simple
devfs_only() call that is much easier to understand what is happening.

Secondly, as to Richard's assertion that this patch will break things,
here are a list of the block and then character drivers that "might"
break if "devfs=only" is enabled, and this patch is applied:

Block drivers whose usage in "devfs=only" mode will be affected:
cpqarray.c - actually this driver looks broken for devfs anyway
stram.c
fd177d.c
mfmhd.c
amiflop.c
cciss.c
pf.c
swim_iop.c
z2ram.c
ataraid.c
i20_block.c
ftl.c
ntflcore.c
jsflash.c

Char drivers whose usage in "devfs=only" mode will be affected:
ds1302.c - arch/cris driver
eeprom.c - arch/cris driver
gpio.c - arch/cris driver
i2c.c - arch/cris driver
sync_serial.c - arch/cris driver
cpuid.c
msr.c
drm_stub.c
raw.c
pcilynx.c
lincfg.c
ds.c
dpt_i2o.c
megaraid.c
phonedev.c
psdev.c - fs/intermesso driver

As you can see, this list is _much_ smaller than the list of drivers
that have had to have the "devfs_*" function change to them. Please do
not penalize all of the kernel because these few drivers have not been
"fixed". If "devfs=only" mode is important enough to users of these
drivers, they will be fixed.

Thirdly, I got a machine up and running with devfs, and this patch does
not effect it at all. To be fair, I could not boot _any_ recent 2.5
kernel without this patch in "devfs=only" mode, but that must be because
the Gentoo people are not crazy enough to set up their distro to run in
this devfs mode. And these people are pretty dedicated to devfs, so I
can't test "devfs=only" mode myself with this patch. But from looking
at the above list of drivers, I don't see anything preventing this from
happening with my (and most everyone else's) hardware.

So Linus, please take these changesets. A large number of driver
authors have told me they would like this patch into the kernel, and it
cleans up the driver API to be much saner (as well as making devfs less
intrusive to all drivers).

Please pull from:
bk://linuxusb.bkbits.net/devfs-2.5

thanks,

greg k-h

Overall diffstat for these changesets:

Change...@1.546, 2002-07-30 21:46:34-07:00, g...@kroah.com
Remove the devfs_should* functions I added, and replace them with one devfs_only() call

This now explains what is really going on much better than before.

fs/block_dev.c | 4 +--
fs/devfs/base.c | 50 +++-------------------------------------
fs/devices.c | 4 +--
include/linux/devfs_fs_kernel.h | 19 +--------------
4 files changed, 10 insertions(+), 67 deletions(-)
------

Change...@1.545, 2002-07-30 15:40:49-07:00, g...@kroah.com
Removed devfs_register_blkdev and devfs_unregister_blkdev.

Use register_blkdev and unregister_blkdev as before, and everything will work just fine.

Change...@1.544, 2002-07-30 14:38:11-07:00, g...@kroah.com
Removed devfs_register_chrdev and devfs_unregister_chrdev.

Use register_chrdev and unregister_chrdev as before, and everything will work.

read more »

by **Greg K** » Fri, 02 Aug 2002 03:40:09

And here's the additional patch that I made on top of the previous two I
sent to the list yesterday:

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet 1.545 -> 1.546
# fs/devfs/base.c 1.47 -> 1.48
# fs/devices.c 1.8 -> 1.9
# include/linux/devfs_fs_kernel.h 1.14 -> 1.15
# fs/block_dev.c 1.76 -> 1.77
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------

# Remove the devfs_should* functions I added, and replace them with one devfs_only() call
#
# This now explains what is really going on much better than before.
# --------------------------------------------
#
diff -Nru a/fs/block_dev.c b/fs/block_dev.c
--- a/fs/block_dev.c Wed Jul 31 11:23:15 2002

int register_blkdev(unsigned int major, const char * name, struct block_device_operations *bdops)
{
- if (devfs_should_register_blkdev())
+ if (devfs_only())
return 0;
if (major == 0) {

int unregister_blkdev(unsigned int major, const char * name)
{
- if (devfs_should_unregister_blkdev())
+ if (devfs_only())
return 0;
if (major >= MAX_BLKDEV)
return -EINVAL;
diff -Nru a/fs/devfs/base.c b/fs/devfs/base.c
--- a/fs/devfs/base.c Wed Jul 31 11:23:15 2002

/**
- * devfs_should_register_chrdev - should we register a conventional character driver.
+ * devfs_only - returns if "devfs=only" is a boot option
*
- * If "devfs=only" this function will return -1, otherwise 0 is returned.
+ * If "devfs=only" this function will return 1, otherwise 0 is returned.
*/
-int devfs_should_register_chrdev (void)
+int devfs_only (void)
{
if (boot_options & OPTION_ONLY)
- return -1;
+ return 1;
return 0;
}

-
-/**
- * devfs_should_register_blkdev - should we register a conventional block driver.
- *
- * If the "devfs=only" option was provided at boot time, this function will
- * return -1, otherwise 0 is returned.
- */
-
-int devfs_should_register_blkdev (void)
-{
- if (boot_options & OPTION_ONLY)
- return -1;
- return 0;
-}
-
-
-/**
- * devfs_should_unregister_chrdev - should we unregister a conventional character driver.
- *
- * If "devfs=only" this function will return -1, otherwise 0 is returned
- */
-int devfs_should_unregister_chrdev (void)
-{
- if (boot_options & OPTION_ONLY)
- return -1;
- return 0;
-}
-
-
-/**
- * devfs_should_unregister_blkdev - should we unregister a conventional block driver.
- *
- * If the "devfs=only" option was provided at boot time, this function will
- * return -1, otherwise 0 is returned.
- */
-
-int devfs_should_unregister_blkdev (void)
-{
- if (boot_options & OPTION_ONLY)
- return -1;
- return 0;
-}

/**
* devfs_setup - Process kernel boot options.
diff -Nru a/fs/devices.c b/fs/devices.c
--- a/fs/devices.c Wed Jul 31 11:23:15 2002

int register_chrdev(unsigned int major, const char * name, struct file_operations *fops)
{
- if (devfs_should_register_chrdev())
+ if (devfs_only())
return 0;
if (major == 0) {

int unregister_chrdev(unsigned int major, const char * name)
{
- if (devfs_should_register_chrdev())
+ if (devfs_only())
return 0;
if (major >= MAX_CHRDEV)
return -EINVAL;
diff -Nru a/include/linux/devfs_fs_kernel.h b/include/linux/devfs_fs_kernel.h
--- a/include/linux/devfs_fs_kernel.h Wed Jul 31 11:23:15 2002

extern void devfs_auto_unregister (devfs_handle_t master,devfs_handle_t slave);
extern devfs_handle_t devfs_get_unregister_slave (devfs_handle_t master);
extern const char *devfs_get_name (devfs_handle_t de, unsigned int *namelen);
-extern int devfs_should_register_chrdev (void);
-extern int devfs_should_register_blkdev (void);
-extern int devfs_should_unregister_chrdev (void);
-extern int devfs_should_unregister_blkdev (void);
+extern int devfs_only (void);

extern void devfs_register_tape (devfs_handle_t de);

{
return NULL;
}
-static inline int devfs_should_register_chrdev (void)
-{
- return 0;
-}
-static inline int devfs_should_register_blkdev (void)
-{
- return 0;
-}
-static inline int devfs_should_unregister_chrdev (void)
-{
- return 0;
-}
-static inline int devfs_should_unregister_blkdev (void)
+static inline int devfs_only (void)
{
return 0;
}
-
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Very Computer

devfs cleanups for 2.5.29 - take 2

devfs cleanups for 2.5.29 - take 2

devfs cleanups for 2.5.29 - take 2