From 5eb7f7bcd3431cd8f634b02b71bd78f6162c2af3 Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Tue, 16 Dec 2008 15:33:59 +1100 Subject: Initial device handler code Mount discovered devices, and set up symlinks for UUID and LABELs Signed-off-by: Jeremy Kerr --- discover/device-handler.c | 258 +++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 244 insertions(+), 14 deletions(-) (limited to 'discover/device-handler.c') diff --git a/discover/device-handler.c b/discover/device-handler.c index 0e902df..5d40ebe 100644 --- a/discover/device-handler.c +++ b/discover/device-handler.c @@ -1,8 +1,20 @@ +#include +#include +#include +#include +#include +#include + #include #include #include "device-handler.h" +#include "udev.h" +#include "log.h" +#include "paths.h" + +#define MOUNT_BIN "/bin/mount" struct device_handler { struct discover_server *server; @@ -11,21 +23,20 @@ struct device_handler { int n_devices; }; -struct device_handler *device_handler_init(struct discover_server *server) -{ - struct device_handler *handler; - - handler = talloc(NULL, struct device_handler); - handler->devices = NULL; - handler->n_devices = 0; +struct discover_context { + char *device_path; + char *mount_path; + struct udev_event *event; + struct device *device; + char **links; + int n_links; +}; - return handler; -} +struct mount_map { + char *device_path; + char *mount_point; +}; -void device_handler_destroy(struct device_handler *devices) -{ - talloc_free(devices); -} static struct boot_option options[] = { { @@ -54,9 +65,228 @@ int device_handler_get_current_devices(struct device_handler *handler, return 1; } +static int mkdir_recursive(const char *dir) +{ + struct stat statbuf; + char *str, *sep; + int mode = 0755; -int device_handler_event(struct device_handler *handler, + if (!*dir) + return 0; + + if (!stat(dir, &statbuf)) { + if (!S_ISDIR(statbuf.st_mode)) { + pb_log("%s: %s exists, but isn't a directory\n", + __func__, dir); + return -1; + } + return 0; + } + + str = talloc_strdup(NULL, dir); + sep = strchr(*str == '/' ? str + 1 : str, '/'); + + while (1) { + + /* terminate the path at sep */ + if (sep) + *sep = '\0'; + + if (mkdir(str, mode) && errno != EEXIST) { + pb_log("mkdir(%s): %s\n", str, strerror(errno)); + return -1; + } + + if (!sep) + break; + + /* reset dir to the full path */ + strcpy(str, dir); + sep = strchr(sep + 1, '/'); + } + + talloc_free(str); + + return 0; +} + +static void setup_device_links(struct discover_context *ctx) +{ + struct link { + char *env, *dir; + } *link, links[] = { + { + .env = "ID_FS_UUID", + .dir = "disk/by-uuid" + }, + { + .env = "ID_FS_LABEL", + .dir = "disk/by-label" + }, + { + .env = NULL + } + }; + + for (link = links; link->env; link++) { + char *enc, *dir, *path; + const char *value; + + value = udev_event_param(ctx->event, link->env); + if (!value) + continue; + + enc = encode_label(ctx, value); + dir = join_paths(ctx, mount_base(), link->dir); + path = join_paths(ctx, dir, value); + + if (!mkdir_recursive(dir)) { + unlink(path); + if (symlink(ctx->mount_path, path)) { + pb_log("symlink(%s,%s): %s\n", + ctx->mount_path, path, + strerror(errno)); + talloc_free(path); + } else { + int i = ctx->n_links++; + ctx->links = talloc_realloc(ctx, + ctx->links, char *, + ctx->n_links); + ctx->links[i] = path; + } + + } + + talloc_free(dir); + talloc_free(enc); + } +} + +static int mount_device(struct discover_context *ctx) +{ + const char *mountpoint; + struct stat statbuf; + int status; + pid_t pid; + + if (!ctx->mount_path) { + mountpoint = mountpoint_for_device(ctx->device_path); + ctx->mount_path = talloc_strdup(ctx, mountpoint); + } + + if (stat(ctx->mount_path, &statbuf)) { + if (mkdir(ctx->mount_path, 0755)) { + pb_log("couldn't create mount directory %s: %s\n", + ctx->mount_path, strerror(errno)); + return -1; + } + } else { + if (!S_ISDIR(statbuf.st_mode)) { + pb_log("mountpoint %s exists, but isn't a directory\n", + ctx->mount_path); + return -1; + } + } + + pid = fork(); + if (pid == -1) { + pb_log("%s: fork failed: %s\n", __func__, strerror(errno)); + return -1; + } + + if (pid == 0) { + execl(MOUNT_BIN, MOUNT_BIN, ctx->device_path, ctx->mount_path, + "-o", "ro", NULL); + exit(EXIT_FAILURE); + } + + if (waitpid(pid, &status, 0) == -1) { + pb_log("%s: waitpid failed: %s\n", __func__, + strerror(errno)); + return -1; + } + + if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) + return -1; + + setup_device_links(ctx); + return 0; +} + +static int handle_add_event(struct device_handler *handler, + struct udev_event *event) +{ + struct discover_context *ctx; + const char *devname; + int rc; + + /* create our context */ + ctx = talloc(NULL, struct discover_context); + ctx->event = event; + ctx->mount_path = NULL; + ctx->links = NULL; + ctx->n_links = 0; + + devname = udev_event_param(ctx->event, "DEVNAME"); + if (!devname) { + pb_log("no devname for %s?\n", event->device); + return 0; + } + + ctx->device_path = talloc_strdup(ctx, devname); + + rc = mount_device(ctx); + if (rc) { + pb_log("mount_device failed for %s\n", event->device); + talloc_free(ctx); + return 0; + } + + talloc_free(ctx); + + return 0; +} + +static int handle_remove_event(struct device_handler *handler, struct udev_event *event) { return 0; } + +int device_handler_event(struct device_handler *handler, + struct udev_event *event) +{ + int rc; + + switch (event->action) { + case UDEV_ACTION_ADD: + rc = handle_add_event(handler, event); + break; + + case UDEV_ACTION_REMOVE: + rc = handle_remove_event(handler, event); + break; + } + + return rc; +} + +struct device_handler *device_handler_init(struct discover_server *server) +{ + struct device_handler *handler; + + handler = talloc(NULL, struct device_handler); + handler->devices = NULL; + handler->n_devices = 0; + + /* set up our mount point base */ + mkdir_recursive(mount_base()); + + return handler; +} + +void device_handler_destroy(struct device_handler *devices) +{ + talloc_free(devices); +} + -- cgit v1.2.1