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authorTejun Heo <tj@kernel.org>2008-11-26 14:03:55 +0300
committerMiklos Szeredi <miklos@szeredi.hu>2008-11-26 14:03:55 +0300
commit8599396b5062bf6bd2a0b433503849e2322df1c2 (patch)
tree8ce5f253eaf5fe28324c497db780d824ea60bb5c /fs/fuse
parentacf99433d98c2570a619d8fb8b51abce4e532059 (diff)
downloadlinux-8599396b5062bf6bd2a0b433503849e2322df1c2.tar.xz
fuse: implement unsolicited notification
Clients always used to write only in response to read requests. To implement poll efficiently, clients should be able to issue unsolicited notifications. This patch implements basic notification support. Zero fuse_out_header.unique is now accepted and considered unsolicited notification and the error field contains notification code. This patch doesn't implement any actual notification. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Diffstat (limited to 'fs/fuse')
-rw-r--r--fs/fuse/dev.c27
1 files changed, 25 insertions, 2 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 225388f54ae7..ffd670bb8c8c 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -816,6 +816,15 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
return err;
}
+static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
+ unsigned int size, struct fuse_copy_state *cs)
+{
+ switch (code) {
+ default:
+ return -EINVAL;
+ }
+}
+
/* Look up request on processing list by unique ID */
static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
{
@@ -879,9 +888,23 @@ static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
err = fuse_copy_one(&cs, &oh, sizeof(oh));
if (err)
goto err_finish;
+
+ err = -EINVAL;
+ if (oh.len != nbytes)
+ goto err_finish;
+
+ /*
+ * Zero oh.unique indicates unsolicited notification message
+ * and error contains notification code.
+ */
+ if (!oh.unique) {
+ err = fuse_notify(fc, oh.error, nbytes - sizeof(oh), &cs);
+ fuse_copy_finish(&cs);
+ return err ? err : nbytes;
+ }
+
err = -EINVAL;
- if (!oh.unique || oh.error <= -1000 || oh.error > 0 ||
- oh.len != nbytes)
+ if (oh.error <= -1000 || oh.error > 0)
goto err_finish;
spin_lock(&fc->lock);