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authorStefan Richter <stefanr@s5r6.in-berlin.de>2010-07-22 11:56:38 +0200
committerStefan Richter <stefanr@s5r6.in-berlin.de>2010-07-27 11:04:10 +0200
commitc7b2a99c66e7b40d8843a70f2981e375eeedf062 (patch)
tree56039d14506b685e009f0b501264cba08d3e5484 /drivers/firewire/nosy.c
parentb5e47729043c9224b21ab3dc7c63e8a38dbb4923 (diff)
downloadlinux-c7b2a99c66e7b40d8843a70f2981e375eeedf062.tar.bz2
firewire: nosy: convert to unlocked ioctl
The required serialization of NOSY_IOC_START and NOSY_IOC_STOP is already provided by the client_list_lock. NOSY_IOC_FILTER does not really require serialization since accesses to tcode_mask are atomic on any sane CPU architecture. Nevertheless, make it explicit that we want this to be atomic by means of client_list_lock (which also surrounds the other tcode_mask access in the IRQ handler). While we are at it, change the type of tcode_mask to u32 for consistency with the user API. NOSY_IOC_GET_STATS does not require serialization against itself. But there is a bug here regarding concurrent updates of the two counters by the IRQ handler. Fix it by taking the client_list_lock in this ioctl too. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Diffstat (limited to 'drivers/firewire/nosy.c')
-rw-r--r--drivers/firewire/nosy.c29
1 files changed, 17 insertions, 12 deletions
diff --git a/drivers/firewire/nosy.c b/drivers/firewire/nosy.c
index ea392d0985a5..6470514190d5 100644
--- a/drivers/firewire/nosy.c
+++ b/drivers/firewire/nosy.c
@@ -108,7 +108,7 @@ struct pcilynx {
struct client {
struct pcilynx *lynx;
- unsigned long tcode_mask;
+ u32 tcode_mask;
struct packet_buffer buffer;
struct list_head link;
};
@@ -351,17 +351,20 @@ nosy_read(struct file *file, char *buffer, size_t count, loff_t *offset)
return packet_buffer_get(&client->buffer, buffer, count);
}
-static int
-nosy_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
+static long
+nosy_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct client *client = file->private_data;
+ spinlock_t *client_list_lock = &client->lynx->client_list_lock;
struct nosy_stats stats;
switch (cmd) {
case NOSY_IOC_GET_STATS:
+ spin_lock_irq(client_list_lock);
stats.total_packet_count = client->buffer.total_packet_count;
- stats.lost_packet_count = client->buffer.lost_packet_count;
+ stats.lost_packet_count = client->buffer.lost_packet_count;
+ spin_unlock_irq(client_list_lock);
+
if (copy_to_user((void *) arg, &stats, sizeof stats))
return -EFAULT;
else
@@ -376,7 +379,9 @@ nosy_ioctl(struct inode *inode, struct file *file,
return 0;
case NOSY_IOC_FILTER:
+ spin_lock_irq(client_list_lock);
client->tcode_mask = arg;
+ spin_unlock_irq(client_list_lock);
return 0;
default:
@@ -386,12 +391,12 @@ nosy_ioctl(struct inode *inode, struct file *file,
}
static const struct file_operations nosy_ops = {
- .owner = THIS_MODULE,
- .read = nosy_read,
- .ioctl = nosy_ioctl,
- .poll = nosy_poll,
- .open = nosy_open,
- .release = nosy_release,
+ .owner = THIS_MODULE,
+ .read = nosy_read,
+ .unlocked_ioctl = nosy_ioctl,
+ .poll = nosy_poll,
+ .open = nosy_open,
+ .release = nosy_release,
};
#define PHY_PACKET_SIZE 12 /* 1 payload, 1 inverse, 1 ack = 3 quadlets */
@@ -409,7 +414,7 @@ packet_handler(struct pcilynx *lynx)
{
unsigned long flags;
struct client *client;
- unsigned long tcode_mask;
+ u32 tcode_mask;
size_t length;
struct link_packet *packet;
struct timeval tv;