[PATCH] uml ubd driver: change ubd_lock to be a mutex
This lock protects ubd setup and teardown, so is only used in process context;
beyond that, during such setup memory allocations must be performed and some
generic functions which can sleep must be called (such as add_disk()). So the
only correct solution is to make it a mutex instead of a spin_lock. No other
change is done - this lock must be acquired in different places but it's done
afterwards.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index cdd82e8..a3061ae 100644
--- a/arch/um/drivers/ubd_kern.c
+++ b/arch/um/drivers/ubd_kern.c
@@ -107,7 +107,8 @@
#define DRIVER_NAME "uml-blkdev"
static DEFINE_SPINLOCK(ubd_io_lock);
-static DEFINE_SPINLOCK(ubd_lock);
+
+static DEFINE_MUTEX(ubd_lock);
static void (*do_ubd)(void);
@@ -314,7 +315,7 @@
}
err = 1;
- spin_lock(&ubd_lock);
+ mutex_lock(&ubd_lock);
if(fake_major != MAJOR_NR){
printk(KERN_ERR "Can't assign a fake major twice\n");
goto out1;
@@ -326,7 +327,7 @@
major);
err = 0;
out1:
- spin_unlock(&ubd_lock);
+ mutex_unlock(&ubd_lock);
return(err);
}
@@ -343,7 +344,7 @@
}
err = 1;
- spin_lock(&ubd_lock);
+ mutex_lock(&ubd_lock);
ubd_dev = &ubd_devs[n];
if(ubd_dev->file != NULL){
@@ -405,7 +406,7 @@
ubd_dev->cow.file = backing_file;
ubd_dev->boot_openflags = flags;
out:
- spin_unlock(&ubd_lock);
+ mutex_unlock(&ubd_lock);
return(err);
}
@@ -710,11 +711,11 @@
}
if(n == -1) return(0);
- spin_lock(&ubd_lock);
+ mutex_lock(&ubd_lock);
err = ubd_add(n);
if(err)
ubd_devs[n].file = NULL;
- spin_unlock(&ubd_lock);
+ mutex_unlock(&ubd_lock);
return(err);
}
@@ -731,7 +732,7 @@
}
ubd_dev = &ubd_devs[n];
- spin_lock(&ubd_lock);
+ mutex_lock(&ubd_lock);
if(ubd_dev->file == NULL){
CONFIG_CHUNK(str, size, len, "", 1);
@@ -747,7 +748,7 @@
else CONFIG_CHUNK(str, size, len, "", 1);
out:
- spin_unlock(&ubd_lock);
+ mutex_unlock(&ubd_lock);
return(len);
}
@@ -766,7 +767,7 @@
struct ubd *ubd_dev;
int err = -ENODEV;
- spin_lock(&ubd_lock);
+ mutex_lock(&ubd_lock);
if(ubd_gendisk[n] == NULL)
goto out;
@@ -795,7 +796,7 @@
*ubd_dev = ((struct ubd) DEFAULT_UBD);
err = 0;
out:
- spin_unlock(&ubd_lock);
+ mutex_unlock(&ubd_lock);
return err;
}