Fix fork handling, where child shares shm with parent

[lttng-ust.git] / libringbuffer / ring_buffer_backend.c

diff --git a/libringbuffer/ring_buffer_backend.c b/libringbuffer/ring_buffer_backend.c
index 466552debaf89c997a27a9a5679aceb52ce8f691..23802e82321416d81782911e081b4359edd1ba35 100644 (file)
--- a/libringbuffer/ring_buffer_backend.c
+++ b/libringbuffer/ring_buffer_backend.c
@@ -8,9 +8,9 @@
 
 #include <urcu/arch.h>
 
-#include "ust/core.h"
+#include "lttng/core.h"
 
-#include <ust/ringbuffer-config.h>
+#include <lttng/ringbuffer-config.h>
 #include "backend.h"
 #include "frontend.h"
 #include "smp.h"
@@ -46,7 +46,7 @@ int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_conf
        align_shm(shmobj, __alignof__(struct lttng_ust_lib_ring_buffer_backend_pages_shmp));
        set_shmp(bufb->array, zalloc_shm(shmobj,
                        sizeof(struct lttng_ust_lib_ring_buffer_backend_pages_shmp) * num_subbuf_alloc));
-       if (unlikely(!shmp(handle, bufb->array)))
+       if (caa_unlikely(!shmp(handle, bufb->array)))
                goto array_error;
 
        /*
@@ -56,7 +56,7 @@ int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_conf
        align_shm(shmobj, PAGE_SIZE);
        set_shmp(bufb->memory_map, zalloc_shm(shmobj,
                        subbuf_size * num_subbuf_alloc));
-       if (unlikely(!shmp(handle, bufb->memory_map)))
+       if (caa_unlikely(!shmp(handle, bufb->memory_map)))
                goto memory_map_error;
 
        /* Allocate backend pages array elements */
@@ -74,7 +74,7 @@ int lib_ring_buffer_backend_allocate(const struct lttng_ust_lib_ring_buffer_conf
        set_shmp(bufb->buf_wsb, zalloc_shm(shmobj,
                                sizeof(struct lttng_ust_lib_ring_buffer_backend_subbuffer)
                                * num_subbuf));
-       if (unlikely(!shmp(handle, bufb->buf_wsb)))
+       if (caa_unlikely(!shmp(handle, bufb->buf_wsb)))
                goto free_array;
 
        for (i = 0; i < num_subbuf; i++)
@@ -129,14 +129,6 @@ int lib_ring_buffer_backend_create(struct lttng_ust_lib_ring_buffer_backend *buf
                                                handle, shmobj);
 }
 
-void lib_ring_buffer_backend_free(struct lttng_ust_lib_ring_buffer_backend *bufb)
-{
-       /* bufb->buf_wsb will be freed by shm teardown */
-       /* bufb->array[i] will be freed by shm teardown */
-       /* bufb->array will be freed by shm teardown */
-       bufb->allocated = 0;
-}
-
 void lib_ring_buffer_backend_reset(struct lttng_ust_lib_ring_buffer_backend *bufb,
                                   struct lttng_ust_shm_handle *handle)
 {
@@ -190,7 +182,6 @@ void channel_backend_reset(struct channel_backend *chanb)
  * @chanb: channel backend
  * @name: channel name
  * @config: client ring buffer configuration
- * @priv: client private data
  * @parent: dentry of parent directory, %NULL for root directory
  * @subbuf_size: size of sub-buffers (> PAGE_SIZE, power of 2)
  * @num_subbuf: number of sub-buffers (power of 2)
@@ -207,7 +198,7 @@ void channel_backend_reset(struct channel_backend *chanb)
 int channel_backend_init(struct channel_backend *chanb,
                         const char *name,
                         const struct lttng_ust_lib_ring_buffer_config *config,
-                        void *priv, size_t subbuf_size, size_t num_subbuf,
+                        size_t subbuf_size, size_t num_subbuf,
                         struct lttng_ust_shm_handle *handle)
 {
        struct channel *chan = caa_container_of(chanb, struct channel, backend);
@@ -235,7 +226,6 @@ int channel_backend_init(struct channel_backend *chanb,
        if (ret)
                return ret;
 
-       chanb->priv = priv;
        chanb->buf_size = num_subbuf * subbuf_size;
        chanb->subbuf_size = subbuf_size;
        chanb->buf_size_order = get_count_order(chanb->buf_size);
@@ -313,15 +303,6 @@ int channel_backend_init(struct channel_backend *chanb,
        return 0;
 
 free_bufs:
-       if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
-               for_each_possible_cpu(i) {
-                       struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chanb->buf[i].shmp);
-
-                       if (!buf->backend.allocated)
-                               continue;
-                       lib_ring_buffer_free(buf, handle);
-               }
-       }
        /* We only free the buffer data upon shm teardown */
 end:
        return -ENOMEM;
@@ -336,24 +317,7 @@ end:
 void channel_backend_free(struct channel_backend *chanb,
                          struct lttng_ust_shm_handle *handle)
 {
-       const struct lttng_ust_lib_ring_buffer_config *config = &chanb->config;
-       unsigned int i;
-
-       if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) {
-               for_each_possible_cpu(i) {
-                       struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chanb->buf[i].shmp);
-
-                       if (!buf->backend.allocated)
-                               continue;
-                       lib_ring_buffer_free(buf, handle);
-               }
-       } else {
-               struct lttng_ust_lib_ring_buffer *buf = shmp(handle, chanb->buf[0].shmp);
-
-               CHAN_WARN_ON(chanb, !buf->backend.allocated);
-               lib_ring_buffer_free(buf, handle);
-       }
-       /* We only free the buffer data upon shm teardown */
+       /* SHM teardown takes care of everything */
 }
 
 /**
@@ -378,7 +342,7 @@ size_t lib_ring_buffer_read(struct lttng_ust_lib_ring_buffer_backend *bufb, size
        orig_len = len;
        offset &= chanb->buf_size - 1;
 
-       if (unlikely(!len))
+       if (caa_unlikely(!len))
                return 0;
        id = bufb->buf_rsb.id;
        sb_bindex = subbuffer_id_get_index(config, id);