Adding perf_data_file__write interface to centralize output to files.
The function prototype is:
  ssize_t perf_data_file__write(struct perf_data_file *file,
                                void *buf, size_t size);
Returns number of bytes written or -1 in case of error.
NOTE: Also indenting 'struct perf_data_file' members, no functional
      change done.
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1385634619-8129-6-git-send-email-jolsa@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
		
	
			
		
			
				
	
	
		
			126 lines
		
	
	
	
		
			2.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			126 lines
		
	
	
	
		
			2.3 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
#include <linux/compiler.h>
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#include <linux/kernel.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <string.h>
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#include "data.h"
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#include "util.h"
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static bool check_pipe(struct perf_data_file *file)
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{
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	struct stat st;
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	bool is_pipe = false;
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	int fd = perf_data_file__is_read(file) ?
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		 STDIN_FILENO : STDOUT_FILENO;
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	if (!file->path) {
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		if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
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			is_pipe = true;
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	} else {
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		if (!strcmp(file->path, "-"))
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			is_pipe = true;
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	}
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	if (is_pipe)
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		file->fd = fd;
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	return file->is_pipe = is_pipe;
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}
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static int check_backup(struct perf_data_file *file)
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{
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	struct stat st;
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	if (!stat(file->path, &st) && st.st_size) {
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		/* TODO check errors properly */
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		char oldname[PATH_MAX];
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		snprintf(oldname, sizeof(oldname), "%s.old",
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			 file->path);
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		unlink(oldname);
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		rename(file->path, oldname);
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	}
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	return 0;
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}
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static int open_file_read(struct perf_data_file *file)
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{
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	struct stat st;
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	int fd;
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	fd = open(file->path, O_RDONLY);
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	if (fd < 0) {
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		int err = errno;
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		pr_err("failed to open %s: %s", file->path, strerror(err));
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		if (err == ENOENT && !strcmp(file->path, "perf.data"))
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			pr_err("  (try 'perf record' first)");
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		pr_err("\n");
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		return -err;
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	}
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	if (fstat(fd, &st) < 0)
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		goto out_close;
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	if (!file->force && st.st_uid && (st.st_uid != geteuid())) {
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		pr_err("file %s not owned by current user or root\n",
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		       file->path);
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		goto out_close;
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	}
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	if (!st.st_size) {
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		pr_info("zero-sized file (%s), nothing to do!\n",
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			file->path);
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		goto out_close;
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	}
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	file->size = st.st_size;
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	return fd;
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 out_close:
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	close(fd);
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	return -1;
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}
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static int open_file_write(struct perf_data_file *file)
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{
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	if (check_backup(file))
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		return -1;
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	return open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);
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}
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static int open_file(struct perf_data_file *file)
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{
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	int fd;
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	fd = perf_data_file__is_read(file) ?
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	     open_file_read(file) : open_file_write(file);
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	file->fd = fd;
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	return fd < 0 ? -1 : 0;
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}
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int perf_data_file__open(struct perf_data_file *file)
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{
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	if (check_pipe(file))
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		return 0;
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	if (!file->path)
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		file->path = "perf.data";
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	return open_file(file);
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}
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void perf_data_file__close(struct perf_data_file *file)
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{
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	close(file->fd);
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}
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ssize_t perf_data_file__write(struct perf_data_file *file,
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			      void *buf, size_t size)
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{
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	return writen(file->fd, buf, size);
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}
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