From d6234626d7240952da42902b7ef513d56d5a18a7 Mon Sep 17 00:00:00 2001 From: yangjiaqi Date: Thu, 25 Nov 2021 11:32:37 +0800 Subject: [PATCH 03/17] show-dev-name-in-container --- src/proc_fuse.c | 145 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 143 insertions(+), 2 deletions(-) diff --git a/src/proc_fuse.c b/src/proc_fuse.c index 94168c9..7372a36 100644 --- a/src/proc_fuse.c +++ b/src/proc_fuse.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include "proc_fuse.h" @@ -448,6 +449,132 @@ static void get_blkio_io_value(char *str, unsigned major, unsigned minor, } } +struct devinfo { + char *name; + int major, minor; + struct devinfo *next; +}; + +int getns(pid_t pid, const char *ns_type) +{ + char fpath[100]; + memset(fpath, 0, sizeof(fpath)); + snprintf(fpath, 99, "/proc/%d/ns/%s", pid, ns_type); + return open(fpath, O_RDONLY); +} + +struct devinfo* container_dev_read(pid_t pid) { + int nsfd; + DIR *dir; + struct dirent *ptr; + struct stat dev_stat; + struct devinfo *head = NULL, *end; + char fpath[100], dev_name[100]; + pid_t child_pid; + int mypipe[2]; + int dev_num; + FILE *stream; + + if (pipe(mypipe) < 0) { + perror("Error creating pipe"); + return head; + } + + child_pid = fork(); + if (child_pid < 0) { + close(mypipe[0]); + close(mypipe[1]); + perror("Error forking child"); + return head; + } + if (child_pid == 0) { + close(mypipe[0]); + stream = fdopen(mypipe[1], "w"); + if (stream == NULL) { + lxcfs_error("Error opening pipe for writing: %s\n", strerror(errno)); + goto child_out; + } + nsfd = getns(pid, "mnt"); + if (nsfd < 0) { + lxcfs_error("Error getting mnt ns: %s\n", strerror(errno)); + goto child_out; + } + if (setns(nsfd, 0) < 0) { + lxcfs_error("Error setting mnt ns: %s\n", strerror(errno)); + goto child_out; + } + dir = opendir("/dev"); + if (dir == NULL) { + lxcfs_error("Error opening dir /dev: %s\n", strerror(errno)); + goto child_out; + } + while ((ptr = readdir(dir)) != NULL) { + if (ptr->d_type != DT_BLK && ptr->d_type != DT_CHR) { + continue; + } + memset(fpath, 0, sizeof(fpath)); + snprintf(fpath, 99, "/dev/%s", ptr->d_name); + stat(fpath, &dev_stat); + fprintf(stream, "%s %d ", ptr->d_name, dev_stat.st_rdev); + fflush(stream); + } + closedir(dir); + stat("/", &dev_stat); + dev_num = dev_stat.st_dev & (~0xf); + fprintf(stream, "sda %d end 0 ", dev_num); + fflush(stream); + fclose(stream); + exit(0); + } + +child_out: + close(mypipe[1]); + stream = fdopen(mypipe[0], "r"); + if (stream == NULL) { + lxcfs_error("Error opening pipe for reading: %s\n", strerror(errno)); + goto err; + } + while (fscanf(stream, "%100s%d", dev_name, &dev_num) == 2) { + if (dev_num == 0) { + break; + } + if (head == NULL) { + do { + head = (struct devinfo*)malloc(sizeof(struct devinfo)); + } while (!head); + end = head; + } else { + do { + end->next = (struct devinfo*)malloc(sizeof(struct devinfo)); + } while (!end->next); + end = end->next; + } + end->next = NULL; + end->name = must_copy_string(dev_name); + end->major = major(dev_num); + end->minor = minor(dev_num); + } +err: + if (stream) + fclose(stream); + if (child_pid > 0) + wait_for_pid(child_pid); + return head; +} + +void free_devinfo_list(struct devinfo *ptr) +{ + struct devinfo *tmp; + while (ptr != NULL) { + tmp = ptr; + ptr = ptr->next; + free(tmp->name); + tmp->name = NULL; + free(tmp); + tmp = NULL; + } +} + struct lxcfs_diskstats { unsigned int major; /* 1 - major number */ unsigned int minor; /* 2 - minor mumber */ @@ -480,6 +607,7 @@ static int proc_diskstats_read(char *buf, size_t size, off_t offset, __do_fclose FILE *f = NULL; struct fuse_context *fc = fuse_get_context(); struct file_info *d = INTTYPE_TO_PTR(fi->fh); + struct devinfo *container_devinfo = NULL, *ptr = NULL; struct lxcfs_diskstats stats = {}; /* helper fields */ uint64_t read_service_time, write_service_time, discard_service_time, read_wait_time, @@ -549,13 +677,22 @@ static int proc_diskstats_read(char *buf, size_t size, off_t offset, if (!f) return 0; + container_devinfo = container_dev_read(initpid); + while (getline(&line, &linelen, f) != -1) { ssize_t l; char lbuf[256]; + memset(stats.dev_name, 0, sizeof(stats.dev_name)); i = sscanf(line, "%u %u %71s", &stats.major, &stats.minor, stats.dev_name); if (i != 3) continue; + for (ptr = container_devinfo; ptr != NULL; ptr = ptr->next) { + if (stats.major == ptr->major && stats.minor == ptr->minor) { + snprintf(stats.dev_name, sizeof(stats.dev_name), "%s", ptr->name); + stats.dev_name[71] = '\0'; + } + } get_blkio_io_value(io_serviced_str, stats.major, stats.minor, "Read", &stats.read); get_blkio_io_value(io_serviced_str, stats.major, stats.minor, "Write", &stats.write); @@ -620,10 +757,14 @@ static int proc_diskstats_read(char *buf, size_t size, off_t offset, continue; l = snprintf(cache, cache_size, "%s", lbuf); - if (l < 0) + if (l < 0) { + free_devinfo_list(container_devinfo); return log_error(0, "Failed to write cache"); - if ((size_t)l >= cache_size) + } + if ((size_t)l >= cache_size) { + free_devinfo_list(container_devinfo); return log_error(0, "Write to cache was truncated"); + } cache += l; cache_size -= l; -- 2.27.0