misc-utils/lsblk-mnt.c

   1 #include "c.h"
   2 #include "pathnames.h"
   3 #include "xalloc.h"
   4 #include "nls.h"
   5
   6 #include <libmount.h>
   7
   8 #include "lsblk.h"
   9
  10 static struct libmnt_table *mtab, *swaps;
  11 static struct libmnt_cache *mntcache;
  12
  13 static int table_parser_errcb(struct libmnt_table *tb __attribute__((__unused__)),
  14                         const char *filename, int line)
  15 {
  16         if (filename)
  17                 warnx(_("%s: parse error at line %d -- ignored"), filename, line);
  18         return 1;
  19 }
  20
  21 static int is_active_swap(const char *filename)
  22 {
  23         if (!swaps) {
  24                 swaps = mnt_new_table();
  25                 if (!swaps)
  26                         return 0;
  27                 if (!mntcache)
  28                         mntcache = mnt_new_cache();
  29
  30                 mnt_table_set_parser_errcb(swaps, table_parser_errcb);
  31                 mnt_table_set_cache(swaps, mntcache);
  32
  33                 if (!lsblk->sysroot)
  34                         mnt_table_parse_swaps(swaps, NULL);
  35                 else {
  36                         char buf[PATH_MAX];
  37                         snprintf(buf, sizeof(buf), "%s" _PATH_PROC_SWAPS, lsblk->sysroot);
  38                         mnt_table_parse_swaps(swaps, buf);
  39                 }
  40         }
  41
  42         return mnt_table_find_srcpath(swaps, filename, MNT_ITER_BACKWARD) != NULL;
  43 }
  44
  45 char *lsblk_device_get_mountpoint(struct lsblk_device *dev)
  46 {
  47         struct libmnt_fs *fs;
  48         const char *fsroot;
  49
  50         assert(dev);
  51         assert(dev->filename);
  52
  53         if (dev->is_mounted || dev->is_swap)
  54                 return dev->mountpoint;
  55
  56         if (!mtab) {
  57                 mtab = mnt_new_table();
  58                 if (!mtab)
  59                         return NULL;
  60                 if (!mntcache)
  61                         mntcache = mnt_new_cache();
  62
  63                 mnt_table_set_parser_errcb(mtab, table_parser_errcb);
  64                 mnt_table_set_cache(mtab, mntcache);
  65
  66                 if (!lsblk->sysroot)
  67                         mnt_table_parse_mtab(mtab, NULL);
  68                 else {
  69                         char buf[PATH_MAX];
  70                         snprintf(buf, sizeof(buf), "%s" _PATH_PROC_MOUNTINFO, lsblk->sysroot);
  71                         mnt_table_parse_mtab(mtab, buf);
  72                 }
  73         }
  74
  75         /* Note that maj:min in /proc/self/mountinfo does not have to match with
  76          * devno as returned by stat(), so we have to try devname too
  77          */
  78         fs = mnt_table_find_devno(mtab, makedev(dev->maj, dev->min), MNT_ITER_BACKWARD);
  79         if (!fs)
  80                 fs = mnt_table_find_srcpath(mtab, dev->filename, MNT_ITER_BACKWARD);
  81         if (!fs) {
  82                 if (is_active_swap(dev->filename)) {
  83                         dev->mountpoint = xstrdup("[SWAP]");
  84                         dev->is_swap = 1;
  85                 } else
  86                         dev->mountpoint = NULL;
  87
  88                 return dev->mountpoint;
  89         }
  90
  91         /* found */
  92         fsroot = mnt_fs_get_root(fs);
  93         if (fsroot && strcmp(fsroot, "/") != 0) {
  94                 /* hmm.. we found bind mount or btrfs subvolume, let's try to
  95                  * get real FS root mountpoint */
  96                 struct libmnt_fs *rfs;
  97                 struct libmnt_iter *itr = mnt_new_iter(MNT_ITER_BACKWARD);
  98
  99                 mnt_table_set_iter(mtab, itr, fs);
 100                 while (mnt_table_next_fs(mtab, itr, &rfs) == 0) {
 101                         fsroot = mnt_fs_get_root(rfs);
 102                         if ((!fsroot || strcmp(fsroot, "/") == 0)
 103                             && mnt_fs_match_source(rfs, dev->filename, mntcache)) {
 104                                 fs = rfs;
 105                                 break;
 106                         }
 107                 }
 108                 mnt_free_iter(itr);
 109         }
 110
 111         DBG(DEV, ul_debugobj(dev, "mountpoint: %s", mnt_fs_get_target(fs)));
 112         dev->mountpoint = xstrdup(mnt_fs_get_target(fs));
 113         dev->is_mounted = 1;
 114         return dev->mountpoint;
 115 }
 116
 117 void lsblk_mnt_init(void)
 118 {
 119         mnt_init_debug(0);
 120 }
 121
 122 void lsblk_mnt_deinit(void)
 123 {
 124         mnt_unref_table(mtab);
 125         mnt_unref_table(swaps);
 126         mnt_unref_cache(mntcache);
 127 }