If the user manually creates a loopback device node in /dev, for example /dev/NAME and uses it to setup a loopback device, the resulting base name of /sys/block/loop* does not match that of /dev/NAME. On some systems, /dev/loop* gets created automatically by using losetup, on others not. The solution is to read the major and minor revision out of /sys/block/NAME/dev and look for the same in /dev. Thus, the correct block device node in /dev can be found.
Signed-off-by: Andreas Reichel <[email protected]> --- tools/ebgpart.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++---------- tools/ebgpart.h | 3 +- 2 files changed, 74 insertions(+), 15 deletions(-) diff --git a/tools/ebgpart.c b/tools/ebgpart.c index 07edb05..05cb1fb 100644 --- a/tools/ebgpart.c +++ b/tools/ebgpart.c @@ -355,25 +355,83 @@ bool check_partition_table(PedDevice *dev) void ped_device_probe_all() { - struct dirent *devfile; + struct dirent *sysblockfile; char fullname[256]; - DIR *devdir = opendir(DEVDIRNAME); - if (!devdir) { - VERBOSE(stderr, "Could not open %s\n", DEVDIRNAME); + DIR *sysblockdir = opendir(SYSBLOCKDIR); + if (!sysblockdir) { + VERBOSE(stderr, "Could not open %s\n", SYSBLOCKDIR); return; } - /* get all files from devdir */ + /* get all files from sysblockdir */ do { - devfile = readdir(devdir); - if (!devfile) - break; - if (strcmp(devfile->d_name, ".") == 0 || - strcmp(devfile->d_name, "..") == 0) + sysblockfile = readdir(sysblockdir); + if (!sysblockfile) break; + if (strcmp(sysblockfile->d_name, ".") == 0 || + strcmp(sysblockfile->d_name, "..") == 0) continue; - - snprintf(fullname, 255, "/dev/%s", devfile->d_name); + snprintf(fullname, 255, "/sys/block/%s/dev", + sysblockfile->d_name); + /* Get major and minor revision from /sys/block/sdX/dev */ + FILE *fh = fopen(fullname, "r"); + if (fh == 0) { + VERBOSE( + stderr, + "Error opening %s for read", fullname); + continue; + } + int fmajor, fminor; + if (fscanf(fh, "%u:%u", &fmajor, &fminor) < 2) { + VERBOSE( + stderr, + "Error reading major/minor of device entry. (%s)\n", + strerror(errno)); + fclose(fh); + continue; + }; + fclose(fh); + VERBOSE(stdout, + "Trying device with: Major = %d, Minor = %d, (%s)\n", + fmajor, fminor, fullname); + /* Check if this file is really in the dev directory */ + snprintf(fullname, 255, "%s/%s", DEVDIR, sysblockfile->d_name); + struct stat fstat; + if (stat(fullname, &fstat) != -1) { + goto devnode_found; + } + /* Node with same name not found in /dev, thus search for node + * with identical Major and Minor revision */ + DIR *devdir = opendir(DEVDIR); + if (!devdir) { + VERBOSE(stderr, "Failed to open %s\n", DEVDIR); + continue; + } + struct dirent *devfile; + do { + devfile = readdir(devdir); + if (!devfile) { + break; + } + snprintf(fullname, 255, "%s/%s", DEVDIR, + devfile->d_name); + if (stat(fullname, &fstat) == -1) { + VERBOSE(stderr, "stat failed on %s\n", + fullname); + break; + } + if (major(fstat.st_rdev) == fmajor && + minor(fstat.st_rdev) == fminor) { + VERBOSE(stdout, "Node found: %s\n", fullname); + break; + } + fullname[0] = 0; + } while (devfile); + closedir(devdir); + devnode_found: + if (strlen(fullname) == 0) { + continue; + } /* This is a block device, so add it to the list*/ PedDevice *dev = calloc(sizeof(PedDevice), 1); asprintf(&dev->model, "N/A"); @@ -385,9 +443,9 @@ void ped_device_probe_all() free(dev->path); free(dev); } - } while (devfile); + } while (sysblockfile); - closedir(devdir); + closedir(sysblockdir); } void ped_partition_destroy(PedPartition *p) diff --git a/tools/ebgpart.h b/tools/ebgpart.h index 76fee9d..679a1d7 100644 --- a/tools/ebgpart.h +++ b/tools/ebgpart.h @@ -41,7 +41,8 @@ #include <string.h> #include <stdlib.h> -#define DEVDIRNAME "/sys/block" +#define SYSBLOCKDIR "/sys/block" +#define DEVDIR "/dev" #define LB_SIZE 512 -- 2.11.0 -- You received this message because you are subscribed to the Google Groups "EFI Boot Guard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/efibootguard-dev/20170710124051.1413-2-andreas.reichel.ext%40siemens.com. For more options, visit https://groups.google.com/d/optout.
