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From: Michal Schmidt <mschmidt@redhat.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Alexey Dobriyan <adobriyan@gmail.com>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	linux-kernel@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	Adrian Bunk <bunk@stusta.de>,
	Alexander Viro <viro@ftp.linux.org.uk>
Subject: Re: [PATCH 58/59] sysctl: Reimplement the sysctl proc support
Date: Wed, 14 Mar 2007 16:44:42 +0100	[thread overview]
Message-ID: <45F8186A.6090408@redhat.com> (raw)
In-Reply-To: <20070314122453.GA5775@elte.hu>

Ingo Molnar wrote:
> * Alexey Dobriyan <adobriyan@gmail.com> wrote:
>   
>> Use register_sysctl_table() for sysctls.
>>     
>
> yes - i just wanted to point out the incompatibility and subtle breakage 
> that this change caused. I'll now have to convert the current code over 
> to sysctl_table, which isnt that hard but not trivial either, and i 
> certainly could make use that time for other purposes.
>
> 	Ingo
>   

How about this? It works for me.

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>

diff --git a/kernel/latency_trace.c b/kernel/latency_trace.c
index e07bb95..a13d001 100644
--- a/kernel/latency_trace.c
+++ b/kernel/latency_trace.c
@@ -19,7 +19,7 @@
 #include <linux/seq_file.h>
 #include <linux/interrupt.h>
 #include <linux/clocksource.h>
-#include <linux/proc_fs.h>
+#include <linux/sysctl.h>
 #include <linux/latency_hist.h>
 #include <linux/utsrelease.h>
 #include <asm/uaccess.h>
@@ -2661,66 +2661,94 @@ void print_traces(struct task_struct *task)
 }
 #endif
 
-static int preempt_read_proc(char *page, char **start, off_t off,
-			     int count, int *eof, void *data)
+#if defined(CONFIG_WAKEUP_TIMING) || defined(CONFIG_EVENT_TRACE)
+
+static int preempt_proc_handler(ctl_table *table, int write, struct file *filp,
+				void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-	cycle_t *max = data;
+#define TMPBUFLEN 21
+	char buf[TMPBUFLEN];
+	size_t left = *lenp;
+	cycle_t *max = table->data;
 
-	return sprintf(page, "%ld\n", cycles_to_usecs(*max));
-}
+	if (!table->data || table->maxlen!=sizeof(cycles_t) || !*lenp ||
+			(*ppos && !write)) {
+		*lenp = 0;
+		return 0;
+	}
 
-static int preempt_write_proc(struct file *file, const char __user *buffer,
-			      unsigned long count, void *data)
-{
-	unsigned int c, done = 0, val, sum = 0;
-	cycle_t *max = data;
+	if (!write) {
+		int len;
 
-	while (count) {
-		if (get_user(c, buffer))
-			return -EFAULT;
-		val = c - '0';
-		buffer++;
-		done++;
-		count--;
-		if (c == 0 || c == '\n')
-			break;
-		if (val > 9)
+		len = snprintf(buf, TMPBUFLEN, "%ld\n", cycles_to_usecs(*max));
+		if (len >= TMPBUFLEN)
 			return -EINVAL;
-		sum *= 10;
-		sum += val;
+		if (len > left)
+			len = left;
+		if (copy_to_user(buffer, buf, len))
+			return -EFAULT;
+		left -= len;
+	} else {
+		unsigned int c, val, sum = 0;
+
+		while (left) {
+			if (get_user(c, (char __user *)buffer))
+				return -EFAULT;
+			val = c - '0';
+			buffer++;
+			left--;
+			if (c == 0 || c == '\n')
+				break;
+			if (val > 9)
+				return -EINVAL;
+			sum *= 10;
+			sum += val;
+		}
+		*max = usecs_to_cycles(sum);
 	}
-	*max = usecs_to_cycles(sum);
-	return done;
+
+	*lenp -= left;
+	*ppos += *lenp;
+	return 0;
 }
 
-#if defined(CONFIG_WAKEUP_TIMING) || defined(CONFIG_EVENT_TRACE)
+static ctl_table preempt_latency_table[] = {
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "preempt_max_latency",
+		.data		= &preempt_max_latency,
+		.maxlen		= sizeof(cycles_t),
+		.mode		= 0644,
+		.proc_handler	= &preempt_proc_handler,
+	},
+#ifdef CONFIG_EVENT_TRACE
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "preempt_thresh",
+		.data		= &preempt_thresh,
+		.maxlen		= sizeof(cycles_t),
+		.mode		= 0644,
+		.proc_handler	= &preempt_proc_handler,
+	},
+#endif
+	{ .ctl_name = 0 }
+};
 
-#define	PROCNAME_PML	"sys/kernel/preempt_max_latency"
-#define PROCNAME_PT	"sys/kernel/preempt_thresh"
+static ctl_table kernel_root[] = {
+	{
+		.ctl_name	= CTL_KERN,
+		.procname	= "kernel",
+		.mode		= 0555,
+		.child		= preempt_latency_table,
+	},
+	{ .ctl_name = 0 }
+};
+
+static struct ctl_table_header *sysctl_header;
 
 static __init int latency_fs_init(void)
 {
-	struct proc_dir_entry *entry;
-
-	if (!(entry = create_proc_entry(PROCNAME_PML, 0644, NULL)))
-		printk("latency_fs_init(): can't create %s\n", PROCNAME_PML);
-	else {
-		entry->nlink = 1;
-		entry->data = &preempt_max_latency;
-		entry->read_proc = preempt_read_proc;
-		entry->write_proc = preempt_write_proc;
-	}
-
-#ifdef CONFIG_EVENT_TRACE
-	if (!(entry = create_proc_entry(PROCNAME_PT, 0644, NULL)))
-		printk("latency_fs_init(): can't create %s\n", PROCNAME_PT);
-	else {
-		entry->nlink = 1;
-		entry->data = &preempt_thresh;
-		entry->read_proc = preempt_read_proc;
-		entry->write_proc = preempt_write_proc;
-	}
-#endif
+	sysctl_header = register_sysctl_table(kernel_root);
 	return 0;
 }
 __initcall(latency_fs_init);



-- 
Michal Schmidt             Kernel Developer
mschmidt@redhat.com    Red Hat Czech s.r.o.


  parent reply	other threads:[~2007-03-14 15:47 UTC|newest]

Thread overview: 104+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-01-16 16:33 [PATCH 0/59] Cleanup sysctl Eric W. Biederman
2007-01-16 16:39 ` [PATCH 1/59] sysctl x25: Remove unnecessary insert_at_head from register_sysctl_table Eric W. Biederman
2007-01-16 16:39 ` [PATCH 2/59] sysctl: Move CTL_SUNRPC to sysctl.h where it belongs Eric W. Biederman
2007-01-16 16:39 ` [PATCH 3/59] sysctl: sunrpc Remove unnecessary insert_at_head flag Eric W. Biederman
2007-01-16 16:39 ` [PATCH 4/59] sysctl: sunrpc Don't unnecessarily set ctl_table->de Eric W. Biederman
2007-01-16 16:39 ` [PATCH 5/59] sysctl: rose remove unnecessary insert_at_head flag Eric W. Biederman
2007-01-16 17:36   ` Ralf Baechle
2007-01-16 16:39 ` [PATCH 6/59] sysctl: netrom " Eric W. Biederman
2007-01-16 16:39 ` [PATCH 7/59] sysctl: llc " Eric W. Biederman
2007-01-16 16:39 ` [PATCH 8/59] sysctl: ipx " Eric W. Biederman
2007-01-16 16:39 ` [PATCH 9/59] sysctl: decnet " Eric W. Biederman
2007-01-16 16:39 ` [PATCH 10/59] sysctl: dccp " Eric W. Biederman
2007-01-16 16:39 ` [PATCH 11/59] sysctl: ax25 " Eric W. Biederman
2007-01-16 16:39 ` [PATCH 12/59] sysctl: atalk " Eric W. Biederman
2007-01-16 16:39 ` [PATCH 13/59] sysctl: xfs " Eric W. Biederman
2007-01-16 16:39 ` [PATCH 14/59] sysctl: C99 convert xfs ctl_tables Eric W. Biederman
2007-01-16 18:16   ` Alexey Dobriyan
2007-01-16 18:37     ` Eric W. Biederman
2007-01-16 18:45     ` [PATCH] sysctl: fixes for my C99 converion " Eric W. Biederman
2007-01-17 17:01   ` [PATCH 14/59] sysctl: C99 convert " Kirill Korotaev
2007-01-17 17:37   ` [xfs-masters] " Eric Sandeen
2007-01-16 16:39 ` [PATCH 15/59] sysctl: scsi remove unnecessary insert_at_head flag Eric W. Biederman
2007-01-16 16:39 ` [PATCH 16/59] sysctl: md Remove " Eric W. Biederman
2007-01-16 16:39 ` [PATCH 17/59] sysctl: mac_hid remove " Eric W. Biederman
2007-01-16 16:39 ` [PATCH 18/59] sysctl: ipmi " Eric W. Biederman
2007-01-17  3:14   ` Benjamin Herrenschmidt
2007-01-16 16:39 ` [PATCH 19/59] sysctl: cdrom " Eric W. Biederman
2007-01-16 16:39 ` [PATCH 20/59] sysctl: cdrom Don't set de->owner Eric W. Biederman
2007-01-16 18:19   ` James Bottomley
2007-01-16 16:39 ` [PATCH 21/59] sysctl: Move CTL_PM into sysctl.h where it belongs Eric W. Biederman
2007-01-16 16:39 ` [PATCH 22/59] sysctl: frv pm remove unnecessary insert_at_head flag Eric W. Biederman
2007-01-16 16:39 ` [PATCH 23/59] sysctl: Move CTL_FRV into sysctl.h where it belongs Eric W. Biederman
2007-01-16 16:39 ` [PATCH 24/59] sysctl: frv remove unnecessary insert_at_head flag Eric W. Biederman
2007-01-16 16:39 ` [PATCH 25/59] sysctl: C99 convert arch/frv/kernel/pm.c Eric W. Biederman
2007-01-17 17:14   ` Kirill Korotaev
2007-01-22 22:21     ` Herbert Poetzl
2007-01-24  9:00     ` David Howells
2007-01-16 16:39 ` [PATCH 26/59] sysctl: C99 convert arch/frv/kernel/sysctl.c Eric W. Biederman
2007-01-16 16:39 ` [PATCH 27/59] sysctl: sn Remove sysctl ABI BREAKAGE Eric W. Biederman
2007-01-16 16:39 ` [PATCH 28/59] sysctl: C99 Convert arch/ia64/sn/kernel/xpc_main.c Eric W. Biederman
2007-01-16 16:39 ` [PATCH 29/59] sysctl: C99 convert arch/ia64/kernel/perfmon and remove ABI breakage Eric W. Biederman
2007-01-16 16:39 ` [PATCH 30/59] sysctl: mips/au1000 Remove sys_sysctl support Eric W. Biederman
2007-01-16 16:39 ` [PATCH 31/59] sysctl: C99 convert the ctl_tables in arch/mips/au1000/common/power.c Eric W. Biederman
2007-01-16 22:20   ` Ingo Oeser
2007-01-16 16:39 ` [PATCH 32/59] sysctl: C99 convert arch/mips/lasat/sysctl.c and remove ABI breakage Eric W. Biederman
2007-01-16 16:39 ` [PATCH 33/59] sysctl: s390 move sysctl definitions to sysctl.h Eric W. Biederman
2007-01-17 17:23   ` Kirill Korotaev
2007-01-16 16:39 ` [PATCH 34/59] sysctl: s390 Remove unnecessary use of insert_at_head Eric W. Biederman
2007-01-16 16:39 ` [PATCH 35/59] sysctl: C99 convert ctl_tables in arch/powerpc/kernel/idle.c Eric W. Biederman
2007-01-17  3:16   ` Benjamin Herrenschmidt
2007-01-16 16:39 ` [PATCH 36/59] sysctl: C99 convert ctl_tables entries in arch/ppc/kernel/ppc_htab.c Eric W. Biederman
2007-01-17  3:16   ` Benjamin Herrenschmidt
2007-01-16 16:39 ` [PATCH 37/59] sysctl: C99 convert arch/sh64/kernel/traps.c and remove ABI breakage Eric W. Biederman
2007-01-16 22:07   ` Paul Mundt
2007-01-16 16:39 ` [PATCH 38/59] sysctl: x86_64 Remove unnecessary use of insert_at_head Eric W. Biederman
2007-01-16 16:39 ` [PATCH 39/59] sysctl: C99 convert ctl_tables in arch/x86_64/ia32/ia32_binfmt.c Eric W. Biederman
2007-01-16 16:39 ` [PATCH 40/59] sysctl: C99 convert ctl_tables in arch/x86_64/kernel/vsyscall.c Eric W. Biederman
2007-01-16 16:39 ` [PATCH 41/59] sysctl: C99 convert ctl_tables in arch/x86_64/mm/init.c Eric W. Biederman
2007-01-16 16:39 ` [PATCH 42/59] sysctl: Remove sys_sysctl support from the hpet timer driver Eric W. Biederman
2007-01-17  7:54   ` Clemens Ladisch
2007-01-16 16:39 ` [PATCH 43/59] sysctl: Remove sys_sysctl support from drivers/char/rtc.c Eric W. Biederman
2007-01-16 16:39 ` [PATCH 44/59] sysctl: Register the sysctl number used by the arlan driver Eric W. Biederman
2007-01-16 16:39 ` [PATCH 45/59] sysctl: C99 convert ctl_tables in drivers/parport/procfs.c Eric W. Biederman
2007-01-16 22:15   ` Ingo Oeser
2007-01-16 23:00     ` Eric W. Biederman
2007-01-16 16:39 ` [PATCH 46/59] sysctl: C99 convert coda ctl_tables and remove binary sysctls Eric W. Biederman
2007-01-16 16:39 ` [PATCH 47/59] sysctl: C99 convert ctl_tables in NTFS and remove sys_sysctl support Eric W. Biederman
2007-01-16 16:39 ` [PATCH 48/59] sysctl: Register the ocfs2 sysctl numbers Eric W. Biederman
2007-01-16 20:37   ` Mark Fasheh
2007-01-16 16:39 ` [PATCH 49/59] sysctl: Move init_irq_proc into init/main where it belongs Eric W. Biederman
2007-01-27 10:51   ` Andrew Morton
2007-01-16 16:39 ` [PATCH 50/59] sysctl: Move utsname sysctls to their own file Eric W. Biederman
2007-01-17 17:41   ` Kirill Korotaev
2007-01-17 19:31     ` Eric W. Biederman
2007-01-22 22:24       ` Herbert Poetzl
2007-01-16 16:39 ` [PATCH 51/59] sysctl: Move SYSV IPC " Eric W. Biederman
2007-01-17 17:44   ` Kirill Korotaev
2007-01-16 16:39 ` [PATCH 52/59] sysctl: Create sys/fs/binfmt_misc as an ordinary sysctl entry Eric W. Biederman
2007-01-16 16:39 ` [PATCH 53/59] sysctl: Remove support for CTL_ANY Eric W. Biederman
2007-01-16 16:39 ` [PATCH 54/59] sysctl: Remove support for directory strategy routines Eric W. Biederman
2007-01-16 16:40 ` [PATCH 55/59] sysctl: Remove insert_at_head from register_sysctl Eric W. Biederman
2007-01-16 16:40 ` [PATCH 56/59] sysctl: factor out sysctl_head_next from do_sysctl Eric W. Biederman
2007-01-16 16:40 ` [PATCH 57/59] sysctl: allow sysctl_perm to be called from outside of sysctl.c Eric W. Biederman
2007-01-16 16:40 ` [PATCH 58/59] sysctl: Reimplement the sysctl proc support Eric W. Biederman
2007-03-14 10:38   ` Ingo Molnar
2007-03-14 10:48     ` Alexey Dobriyan
2007-03-14 12:24       ` Ingo Molnar
2007-03-14 13:34         ` Eric W. Biederman
2007-03-14 13:46           ` Ingo Molnar
2007-03-14 15:44         ` Michal Schmidt [this message]
2007-01-16 16:40 ` [PATCH 59/59] sysctl: Remove the proc_dir_entry member for the sysctl tables Eric W. Biederman
2007-01-16 16:53 ` [PATCH 0/59] Cleanup sysctl H. Peter Anvin
2007-01-16 18:12   ` Eric W. Biederman
2007-01-16 18:35     ` H. Peter Anvin
2007-01-16 18:54       ` Eric W. Biederman
2007-01-16 18:58         ` H. Peter Anvin
2007-01-16 19:03           ` Eric W. Biederman
2007-01-16 19:15             ` H. Peter Anvin
2007-01-16 19:30               ` Eric W. Biederman
2007-01-16 20:02 ` David Howells
2007-01-17  4:21 ` Andi Kleen
2007-01-17 12:10 ` Martin Schwidefsky
2007-01-17 18:10 ` Kirill Korotaev
2007-01-17 19:02   ` Eric W. Biederman

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