From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
The compression logic set all the file_offsets for the cpu_data to zero to
just use absolute offsets. But this breaks tracecmd_read_at() that has a
requirement that every record in a handle has a unique offset. This
includes records on different CPUs.
Make the file_offset unique and start at a new page boundary from the
previous cpu_data. Use next_offset in the input handle to keep track of
the last stored cpu_data and set the next cpu_data file_offset to it.
Also slightly restructure the input handle structure to be a little more
compact.
Fixes: 5113584096350 ("trace-cmd library: Initialize CPU data decompression logic")
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
lib/trace-cmd/trace-input.c | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/lib/trace-cmd/trace-input.c b/lib/trace-cmd/trace-input.c
index aa40d2451ab6..56410fb0c228 100644
--- a/lib/trace-cmd/trace-input.c
+++ b/lib/trace-cmd/trace-input.c
@@ -158,11 +158,12 @@ struct file_section {
struct tracecmd_input {
struct tep_handle *pevent;
- unsigned long file_state;
struct tep_plugin_list *plugin_list;
struct tracecmd_input *parent;
- unsigned long flags;
+ unsigned long file_state;
unsigned long long trace_id;
+ unsigned long long next_offset;
+ unsigned long flags;
int fd;
int long_size;
int page_size;
@@ -1349,6 +1350,8 @@ static void *read_zpage(struct tracecmd_input *handle, int cpu, off64_t offset)
int pindex;
int size;
+ offset -= cpu_data->file_offset;
+
/* Look in the cache of already loaded chunks */
list_for_each_entry(cache, &cpu_data->compress.cache, list) {
if (CHUNK_CHECK_OFFSET(cache->chunk, offset)) {
@@ -2665,8 +2668,11 @@ static int init_cpu_zfile(struct tracecmd_input *handle, int cpu)
if (lseek64(handle->fd, offset, SEEK_SET) == (off_t)-1)
return -1;
- cpu_data->offset = 0;
- cpu_data->file_offset = 0;
+ cpu_data->file_offset = handle->next_offset;
+ handle->next_offset = (handle->next_offset + size + handle->page_size - 1) &
+ ~(handle->page_size - 1);
+ cpu_data->offset = cpu_data->file_offset;
+
cpu_data->file_size = size;
cpu_data->size = size;
return 0;
@@ -2688,12 +2694,15 @@ static int init_cpu_zpage(struct tracecmd_input *handle, int cpu)
cpu_data->compress.count = count;
cpu_data->compress.last_chunk = 0;
- cpu_data->file_offset = 0;
- cpu_data->file_size = 0;
+ cpu_data->file_offset = handle->next_offset;
+
for (i = 0; i < count; i++)
cpu_data->file_size += cpu_data->compress.chunks[i].size;
+
cpu_data->offset = cpu_data->file_offset;
cpu_data->size = cpu_data->file_size;
+ handle->next_offset = (handle->next_offset + cpu_data->size + handle->page_size - 1) &
+ ~(handle->page_size - 1);
return 0;
}
@@ -4249,6 +4258,7 @@ struct tracecmd_input *tracecmd_alloc_fd(int fd, int flags)
read4(handle, &page_size);
handle->page_size = page_size;
+ handle->next_offset = page_size;
offset = lseek64(handle->fd, 0, SEEK_CUR);
handle->total_file_size = lseek64(handle->fd, 0, SEEK_END);
--
2.35.1
|