diff options
| -rw-r--r-- | mapfile.c | 84 |
1 files changed, 38 insertions, 46 deletions
@@ -1,8 +1,8 @@ /* - * mapfile - manage /var/run/mdadm/map. Part of: + * mapfile - keep track of uuid <-> array mapping. Part of: * mdadm - manage Linux "md" devices aka RAID arrays. * - * Copyright (C) 2006-2009 Neil Brown <neilb@suse.de> + * Copyright (C) 2006-2010 Neil Brown <neilb@suse.de> * * * This program is free software; you can redistribute it and/or modify @@ -28,7 +28,7 @@ * Australia */ -/* /var/run/mdadm/map is used to track arrays being created in --incremental +/* The mapfile is used to track arrays being created in --incremental * mode. It particularly allows lookup from UUID to array device, but * also allows the array device name to be easily found. * @@ -38,54 +38,49 @@ * UUID - uuid of the array * path - path where device created: /dev/md/home * - * The preferred location for the map file is /var/run/mdadm/map. - * However /var/run may not exist or be writable in early boot. And if - * no-one has created /var/run/mdadm, we still want to survive. - * So possible locations are: - * /var/run/mdadm/map /dev/.mdadm/map(changable at compile time). - * We read from the first one that exists and write to the first - * one that we can. + * The best place for the mapfile wold be /var/run/mdadm/map. However + * it is needed during initramfs early-boot, and /var/run doesn't exist there + * and certainly doesn't persist through to normal boot. + * So we store it in /dev/.mdadm/map but allow this to be changed at + * compile time. via MAP_DIR and MAP_FILE + * */ #include "mdadm.h" #include <sys/file.h> #include <ctype.h> +#ifndef MAP_DIR +#define MAP_DIR "/dev/.mdadm" +#define MAP_FILE "map" +#endif + #define MAP_READ 0 #define MAP_NEW 1 #define MAP_LOCK 2 #define MAP_DIRNAME 3 #define mapnames(dir, base) { \ - dir "/" base, \ - dir "/" base ".new", \ - dir "/" base ".lock", \ - dir } - -#define MAP_DIRS 2 -char *mapname[MAP_DIRS][4] = { - mapnames("/var/run/mdadm", "map"), - mapnames(MAP_DIR, MAP_FILE), + +char *mapname[4] = { + MAP_DIR "/" MAP_FILE, + MAP_DIR "/" MAP_FILE ".new", + MAP_DIR "/" MAP_FILE ".lock", + MAP_DIR }; int mapmode[3] = { O_RDONLY, O_RDWR|O_CREAT, O_RDWR|O_CREAT|O_TRUNC }; char *mapsmode[3] = { "r", "w", "w"}; -FILE *open_map(int modenum, int *choice) +FILE *open_map(int modenum) { - int i; - - for (i = 0 ; i <= MAP_DIRS ; i++) { - int fd; - if ((mapmode[modenum] & O_CREAT)) - /* Attempt to create directory, don't worry about - * failure. - */ - (void)mkdir(mapname[i][MAP_DIRNAME], 0755); - fd = open(mapname[i][modenum], mapmode[modenum], 0600); - if (fd >= 0) { - *choice = i; - return fdopen(fd, mapsmode[modenum]); - } - } + int fd; + if ((mapmode[modenum] & O_CREAT)) + /* Attempt to create directory, don't worry about + * failure. + */ + (void)mkdir(mapname[MAP_DIRNAME], 0755); + fd = open(mapname[modenum], mapmode[modenum], 0600); + if (fd >= 0) + return fdopen(fd, mapsmode[modenum]); return NULL; } @@ -93,9 +88,8 @@ int map_write(struct map_ent *mel) { FILE *f; int err; - int which; - f = open_map(MAP_NEW, &which); + f = open_map(MAP_NEW); if (!f) return 0; @@ -115,21 +109,20 @@ int map_write(struct map_ent *mel) err = ferror(f); fclose(f); if (err) { - unlink(mapname[which][1]); + unlink(mapname[1]); return 0; } - return rename(mapname[which][1], - mapname[which][0]) == 0; + return rename(mapname[1], + mapname[0]) == 0; } static FILE *lf = NULL; -static int lwhich = 0; int map_lock(struct map_ent **melp) { while (lf == NULL) { struct stat buf; - lf = open_map(MAP_LOCK, &lwhich); + lf = open_map(MAP_LOCK); if (lf == NULL) return -1; if (flock(fileno(lf), LOCK_EX) != 0) { @@ -160,7 +153,7 @@ void map_unlock(struct map_ent **melp) * as only the owner of the lock may * unlink the file */ - unlink(mapname[lwhich][2]); + unlink(mapname[2]); fclose(lf); } lf = NULL; @@ -188,14 +181,13 @@ void map_read(struct map_ent **melp) int devnum, uuid[4]; char metadata[30]; char nam[4]; - int which; *melp = NULL; - f = open_map(MAP_READ, &which); + f = open_map(MAP_READ); if (!f) { RebuildMap(); - f = open_map(MAP_READ, &which); + f = open_map(MAP_READ); } if (!f) return; |