diff options
| author | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2010-07-22 11:56:38 +0200 |
|---|---|---|
| committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2010-07-27 11:04:10 +0200 |
| commit | c7b2a99c66e7b40d8843a70f2981e375eeedf062 (patch) | |
| tree | 56039d14506b685e009f0b501264cba08d3e5484 | |
| parent | b5e47729043c9224b21ab3dc7c63e8a38dbb4923 (diff) | |
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>
| -rw-r--r-- | drivers/firewire/nosy.c | 29 |
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; |