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authorDmitry Monakhov <dmonakhov@openvz.org>2013-04-22 11:41:41 +0400
committerJens Axboe <axboe@kernel.dk>2013-04-30 13:00:02 +0200
commitb8d4a5bf6a049303a29a3275f463f09a490b50ea (patch)
treec9a87f8a6eb8a64d0c5b8304c80bc2c22407289c /kernel/relay.c
parentea56505bedd03e21f497c59cece15a62b4398fc4 (diff)
downloadvexpress-lsk-b8d4a5bf6a049303a29a3275f463f09a490b50ea.tar.gz
relay: move remove_buf_file inside relay_close_buf
Currently remove_buf_file callback is called from from kobject release method. This result in follow issue: # blktrace -d /dev/sda1 -d /dev/sda -o test blktrace_setup() dir = create_dir() rchan = relay_open(dir,...) ->create_buf_file_callback buf_file = debugfs_create_file(dir, ) Userspace will open buf_file. Later we make a decision to stop tracing blktrace_down() relay_close(rhcan) /* just decrement kobj reference */ /* since it is not zero then callback not called */ debugfs_remove(dir) /* FAIL due to non empty dir */ Later user space will close the file and file will be deleted, but directory still exist. user_space_close() ->file_release ->release_buf_file_callback ->debugfs_remove(buf_file ## TESTCASE: # blktrace -d /dev/sda1 -d /dev/sda -o test # After that blktrace infrastructure will remain broken in # an unusable state so: blktrace -d /dev/sda1 will not work. In fact this is general issue, blktrace is just one of examples. We can not reliably remove parent dir until all users close the buf_file. Solution: We don't have to wait that long. File should be deleted inside relay_close_buf(). Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'kernel/relay.c')
-rw-r--r--kernel/relay.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/relay.c b/kernel/relay.c
index 01ab081ac53..a0d200012ad 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -234,7 +234,6 @@ static void relay_destroy_buf(struct rchan_buf *buf)
static void relay_remove_buf(struct kref *kref)
{
struct rchan_buf *buf = container_of(kref, struct rchan_buf, kref);
- buf->chan->cb->remove_buf_file(buf->dentry);
relay_destroy_buf(buf);
}
@@ -484,6 +483,7 @@ static void relay_close_buf(struct rchan_buf *buf)
{
buf->finalized = 1;
del_timer_sync(&buf->timer);
+ buf->chan->cb->remove_buf_file(buf->dentry);
kref_put(&buf->kref, relay_remove_buf);
}