Fix: kernel ctl error codes are based on errno

[lttng-tools.git] / src / common / kernel-consumer / kernel-consumer.c

diff --git a/src/common/kernel-consumer/kernel-consumer.c b/src/common/kernel-consumer/kernel-consumer.c
index 3086abefa2b88cb2abfc5632fafd54cd58946e21..bfec4d2f0db343c067c288f62f42d426ed88afb6 100644 (file)
--- a/src/common/kernel-consumer/kernel-consumer.c
+++ b/src/common/kernel-consumer/kernel-consumer.c
@@ -57,8 +57,8 @@ int lttng_kconsumer_take_snapshot(struct lttng_consumer_stream *stream)
 
        ret = kernctl_snapshot(infd);
        if (ret != 0) {
-               errno = -ret;
                perror("Getting sub-buffer snapshot.");
+               ret = -errno;
        }
 
        return ret;
@@ -77,8 +77,8 @@ int lttng_kconsumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
 
        ret = kernctl_snapshot_get_produced(infd, pos);
        if (ret != 0) {
-               errno = -ret;
                perror("kernctl_snapshot_get_produced");
+               ret = -errno;
        }
 
        return ret;
@@ -97,8 +97,8 @@ int lttng_kconsumer_get_consumed_snapshot(struct lttng_consumer_stream *stream,
 
        ret = kernctl_snapshot_get_consumed(infd, pos);
        if (ret != 0) {
-               errno = -ret;
                perror("kernctl_snapshot_get_consumed");
+               ret = -errno;
        }
 
        return ret;
@@ -174,6 +174,7 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                ret = kernctl_buffer_flush(stream->wait_fd);
                if (ret < 0) {
                        ERR("Failed to flush kernel stream");
+                       ret = -errno;
                        goto end_unlock;
                }
 
@@ -200,6 +201,7 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                                        &stream->max_sb_size);
                        if (ret < 0) {
                                ERR("Getting kernel max_sb_size");
+                               ret = -errno;
                                goto end_unlock;
                        }
                }
@@ -223,6 +225,7 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                        if (ret < 0) {
                                if (errno != EAGAIN) {
                                        PERROR("kernctl_get_subbuf snapshot");
+                                       ret = -errno;
                                        goto end_unlock;
                                }
                                DBG("Kernel consumer get subbuf failed. Skipping it.");
@@ -233,12 +236,14 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                        ret = kernctl_get_subbuf_size(stream->wait_fd, &len);
                        if (ret < 0) {
                                ERR("Snapshot kernctl_get_subbuf_size");
+                               ret = -errno;
                                goto error_put_subbuf;
                        }
 
                        ret = kernctl_get_padded_subbuf_size(stream->wait_fd, &padded_len);
                        if (ret < 0) {
                                ERR("Snapshot kernctl_get_padded_subbuf_size");
+                               ret = -errno;
                                goto error_put_subbuf;
                        }
 
@@ -264,6 +269,7 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
                        ret = kernctl_put_subbuf(stream->wait_fd);
                        if (ret < 0) {
                                ERR("Snapshot kernctl_put_subbuf");
+                               ret = -errno;
                                goto end_unlock;
                        }
                        consumed_pos += stream->max_sb_size;
@@ -292,6 +298,7 @@ int lttng_kconsumer_snapshot_channel(uint64_t key, char *path,
 error_put_subbuf:
        ret = kernctl_put_subbuf(stream->wait_fd);
        if (ret < 0) {
+               ret = -errno;
                ERR("Snapshot kernctl_put_subbuf error path");
        }
 end_unlock:
@@ -355,7 +362,7 @@ int lttng_kconsumer_snapshot_metadata(uint64_t key, char *path,
        do {
                ret_read = lttng_kconsumer_read_subbuffer(metadata_stream, ctx);
                if (ret_read < 0) {
-                       if (ret_read != -EPERM) {
+                       if (ret_read != -EAGAIN) {
                                ERR("Kernel snapshot reading metadata subbuffer (ret: %zd)",
                                                ret_read);
                                goto error;
@@ -851,7 +858,6 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
        /* Get the next subbuffer */
        err = kernctl_get_next_subbuf(infd);
        if (err != 0) {
-               ret = err;
                /*
                 * This is a debug message even for single-threaded consumer,
                 * because poll() have more relaxed criterions than get subbuf,
@@ -860,15 +866,15 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
                 */
                DBG("Reserving sub buffer failed (everything is normal, "
                                "it is due to concurrency)");
+               ret = -errno;
                goto end;
        }
 
        /* Get the full subbuffer size including padding */
        err = kernctl_get_padded_subbuf_size(infd, &len);
        if (err != 0) {
-               errno = -err;
                perror("Getting sub-buffer len failed.");
-               ret = err;
+               ret = -errno;
                goto end;
        }
 
@@ -902,9 +908,8 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
                /* Get subbuffer size without padding */
                err = kernctl_get_subbuf_size(infd, &subbuf_size);
                if (err != 0) {
-                       errno = -err;
                        perror("Getting sub-buffer len failed.");
-                       ret = err;
+                       ret = -errno;
                        goto end;
                }
 
@@ -934,20 +939,18 @@ ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
                break;
        default:
                ERR("Unknown output method");
-               ret = -1;
+               ret = -EPERM;
        }
 
        err = kernctl_put_next_subbuf(infd);
        if (err != 0) {
-               errno = -err;
                if (errno == EFAULT) {
                        perror("Error in unreserving sub buffer\n");
                } else if (errno == EIO) {
                        /* Should never happen with newer LTTng versions */
                        perror("Reader has been pushed by the writer, last sub-buffer corrupted.");
                }
-
-               ret = -err;
+               ret = -errno;
                goto end;
        }
 
@@ -982,8 +985,8 @@ int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
 
                ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len);
                if (ret != 0) {
-                       errno = -ret;
                        PERROR("kernctl_get_mmap_len");
+                       ret = -errno;
                        goto error_close_fd;
                }
                stream->mmap_len = (size_t) mmap_len;