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From: Andrew Morton <akpm@digeo.com>
To: dougg@torque.net
Cc: linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org,
	Alan Cox <alan@lxorguk.ukuu.org.uk>
Subject: Re: illegal context for sleeping ... rmmod ide-cd + ide-scsi
Date: Mon, 5 May 2003 02:01:04 -0700	[thread overview]
Message-ID: <20030505020104.0abc66ba.akpm@digeo.com> (raw)
In-Reply-To: <3EB62347.8020109@torque.net>

Douglas Gilbert <dougg@torque.net> wrote:
>
> In lk 2.5.69 (and in 68) both the ide-cd and ide-scsi
> modules generate a "sleeping function called from illegal
> context" stack trace when removed.
> 
> After "rmmod ide-cd" this appears:
>   Debug: sleeping function called from illegal context
>          at include/asm/semaphore.h:119
>   Call Trace:
>    [<c011dcec>] __might_sleep+0x5c/0x70

ide_unregister_subdriver() does spin_lock_irqsave(&ide_lock), then
calls auto_remove_settings(), which does down(&ide_setting_sem);

A simple fix might be:

diff -puN drivers/ide/ide.c~ide_setting_sem-fix drivers/ide/ide.c
--- 25/drivers/ide/ide.c~ide_setting_sem-fix	2003-05-05 01:59:01.000000000 -0700
+++ 25-akpm/drivers/ide/ide.c	2003-05-05 02:00:21.000000000 -0700
@@ -1131,13 +1131,12 @@ ide_settings_t *ide_find_setting_by_name
  *
  *	Automatically remove all the driver specific settings for this
  *	drive. This function may sleep and must not be called from IRQ
- *	context. Takes the settings_lock
+ *	context. The caller must hold ide_setting_sem.
  */
  
 static void auto_remove_settings (ide_drive_t *drive)
 {
 	ide_settings_t *setting;
-	down(&ide_setting_sem);
 repeat:
 	setting = drive->settings;
 	while (setting) {
@@ -1147,7 +1146,6 @@ repeat:
 		}
 		setting = setting->next;
 	}
-	up(&ide_setting_sem);
 }
 
 /**
@@ -2350,9 +2348,11 @@ int ide_unregister_subdriver (ide_drive_
 {
 	unsigned long flags;
 	
+	down(&ide_setting_sem);
 	spin_lock_irqsave(&ide_lock, flags);
 	if (drive->usage || drive->driver == &idedefault_driver || DRIVER(drive)->busy) {
 		spin_unlock_irqrestore(&ide_lock, flags);
+		up(&ide_setting_sem);
 		return 1;
 	}
 #if defined(CONFIG_BLK_DEV_IDEPNP) && defined(CONFIG_PNP) && defined(MODULE)
@@ -2363,6 +2363,7 @@ int ide_unregister_subdriver (ide_drive_
 	ide_remove_proc_entries(drive->proc, generic_subdriver_entries);
 #endif
 	auto_remove_settings(drive);
+	up(&ide_setting_sem);
 	drive->driver = &idedefault_driver;
 	setup_driver_defaults(drive);
 	spin_unlock_irqrestore(&ide_lock, flags);

_


  reply	other threads:[~2003-05-05  8:47 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-05-05  8:39 illegal context for sleeping ... rmmod ide-cd + ide-scsi Douglas Gilbert
2003-05-05  9:01 ` Andrew Morton [this message]
2003-05-05 11:51   ` Douglas Gilbert
2003-05-05 11:23     ` Alan Cox

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