swapon: use libmount for /proc/swaps parsing

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/Makefile.am b/sys-utils/Makefile.am
index f6ae6ee8e5dd0266b44d373f063350db3c2cf702..5b0a6eb6cf314100f98daf6cd64d6acdd64973c9 100644 (file)
--- a/sys-utils/Makefile.am
+++ b/sys-utils/Makefile.am
@@ -141,8 +141,8 @@ swapon_SOURCES = \
        $(top_srcdir)/lib/linux_version.c \
        $(top_srcdir)/lib/mangle.c
 
-swapon_CFLAGS = $(AM_CFLAGS) -I$(ul_libblkid_incdir)
-swapon_LDADD = $(ul_libblkid_la)
+swapon_CFLAGS = $(AM_CFLAGS) -I$(ul_libblkid_incdir) -I$(ul_libmount_incdir)
+swapon_LDADD = $(ul_libblkid_la) $(ul_libmount_la)
 endif
 
 if BUILD_LSCPU

diff --git a/sys-utils/swapon.c b/sys-utils/swapon.c
index e1e8455a74f6100d51e090ea7f6e01031373147e..a28ff3c1b16874f6f29a29833c32404bb6a8e082 100644 (file)
--- a/sys-utils/swapon.c
+++ b/sys-utils/swapon.c
@@ -16,6 +16,7 @@
 #include <ctype.h>
 
 #include <blkid.h>
+#include <libmount.h>
 
 #include "bitops.h"
 #include "blkdev.h"
@@ -151,110 +152,60 @@ swapoff_usage(FILE *out, int n) {
 /*
  * contents of /proc/swaps
  */
-static int numSwaps;
-static char **swapFiles;       /* array of swap file and partition names */
+static struct libmnt_table *swaps;
+static struct libmnt_cache *mntcache;
 
-static void
-read_proc_swaps(void) {
-       FILE *swaps;
-       char line[1024];
-       char *p, **q;
-       size_t sz;
-
-       numSwaps = 0;
-       swapFiles = NULL;
-
-       swaps = fopen(_PATH_PROC_SWAPS, "r");
-       if (swaps == NULL)
-               return;         /* nothing wrong */
-
-       /* skip the first line */
-       if (!fgets(line, sizeof(line), swaps)) {
-               /* do not whine about an empty file */
-               if (ferror(swaps))
-                       warn(_("%s: unexpected file format"), _PATH_PROC_SWAPS);
-               fclose(swaps);
-               return;
+static struct libmnt_table *get_swaps_table(void)
+{
+       if (!swaps) {
+               swaps = mnt_new_table();
+               if (!swaps)
+                       return NULL;
+               if (!mntcache)
+                       mntcache = mnt_new_cache();
+
+               mnt_table_set_cache(swaps, mntcache);
+               if (mnt_table_parse_swaps(swaps, NULL) != 0)
+                       return NULL;
        }
-       /* make sure the first line is the header */
-       if (line[0] != '\0' && strncmp(line, "Filename\t", 9))
-               goto valid_first_line;
-
-       while (fgets(line, sizeof(line), swaps)) {
- valid_first_line:
-               /*
-                * Cut the line "swap_device  ... more info" after device.
-                * This will fail with names with embedded spaces.
-                */
-               for (p = line; *p && *p != ' '; p++);
-               *p = '\0';
-
-               /* the kernel can use " (deleted)" suffix for paths
-                * in /proc/swaps, we have to remove this junk.
-                */
-               sz = strlen(line);
-               if (sz > PATH_DELETED_SUFFIX_SZ) {
-                      p = line + (sz - PATH_DELETED_SUFFIX_SZ);
-                      if (strcmp(p, PATH_DELETED_SUFFIX) == 0)
-                              *p = '\0';
-               }
-
-               q = xrealloc(swapFiles, (numSwaps+1) * sizeof(*swapFiles));
-               swapFiles = q;
 
-               if ((p = unmangle(line, NULL)) == NULL)
-                       break;
-
-               swapFiles[numSwaps++] = canonicalize_path(p);
-               free(p);
-       }
-       fclose(swaps);
+       return swaps;
 }
 
-/* note that swapFiles are always canonicalized */
-static int
-is_in_proc_swaps(const char *fname) {
-       int i;
-
-       for (i = 0; i < numSwaps; i++)
-               if (swapFiles[i] && !strcmp(fname, swapFiles[i]))
-                       return 1;
-       return 0;
+static int is_active_swap(const char *filename)
+{
+       struct libmnt_table *st = get_swaps_table();
+       return st && mnt_table_find_srcpath(st, filename, MNT_ITER_BACKWARD);
 }
 
 static int
 display_summary(void)
 {
-       FILE *swaps;
-       char line[1024] ;
+       struct libmnt_table *st = get_swaps_table();
+       struct libmnt_iter *itr;
+       struct libmnt_fs *fs;
 
-       if ((swaps = fopen(_PATH_PROC_SWAPS, "r")) == NULL) {
-               warn(_("%s: open failed"), _PATH_PROC_SWAPS);
+       if (!st)
                return -1;
-       }
 
-       while (fgets(line, sizeof(line), swaps)) {
-               char *p, *dev, *cn;
-               if (!strncmp(line, "Filename\t", 9)) {
-                       printf("%s", line);
-                       continue;
-               }
-               for (p = line; *p && *p != ' '; p++);
-               *p = '\0';
-               for (++p; *p && isblank((unsigned int) *p); p++);
+       itr = mnt_new_iter(MNT_ITER_FORWARD);
+       if (!itr)
+               err(EXIT_FAILURE, _("failed to initialize libmount iterator"));
 
-               dev = unmangle(line, NULL);
-               if (!dev)
-                       continue;
-               cn = canonicalize_path(dev);
-               if (cn)
-                       printf("%-39s %s", cn, p);
-               free(dev);
-               free(cn);
+       if (mnt_table_get_nents(st) > 0)
+               printf(_("%-39s\tType\tSize\tUsed\tPriority\n"), _("Filename"));
+
+       while (mnt_table_next_fs(st, itr, &fs) == 0) {
+               printf("%-39s\t%s\t%jd\t%jd\t%d\n",
+                       mnt_fs_get_source(fs),
+                       mnt_fs_get_swaptype(fs),
+                       mnt_fs_get_size(fs),
+                       mnt_fs_get_usedsize(fs),
+                       mnt_fs_get_priority(fs));
        }
 
-       fclose(swaps);
-       return 0 ;
+       mnt_free_iter(itr);
+       return 0;
 }
 
 /* calls mkswap */
@@ -655,8 +606,6 @@ swapon_all(void) {
        struct mntent *fstab;
        int status = 0;
 
-       read_proc_swaps();
-
        fp = setmntent(_PATH_MNTTAB, "r");
        if (fp == NULL)
                err(2, _("%s: open failed"), _PATH_MNTTAB);
@@ -695,7 +644,7 @@ swapon_all(void) {
                        continue;
                }
 
-               if (!is_in_proc_swaps(special) &&
+               if (!is_active_swap(special) &&
                    (!nofail || !access(special, R_OK)))
                        status |= do_swapon(special, pri, dsc, CANONIC);
 
@@ -853,9 +802,18 @@ main_swapoff(int argc, char *argv[]) {
                 * exists as ordinary file, not in procfs.
                 * do_swapoff() exits immediately on EPERM.
                 */
-               read_proc_swaps();
-               for(i=0; i<numSwaps; i++)
-                       status |= do_swapoff(swapFiles[i], QUIET, CANONIC);
+               struct libmnt_table *st = get_swaps_table();
+
+               if (st && mnt_table_get_nents(st) > 0) {
+                       struct libmnt_iter *itr = mnt_new_iter(MNT_ITER_BACKWARD);
+                       struct libmnt_fs *fs;
+
+                       while (itr && mnt_table_next_fs(st, itr, &fs) == 0)
+                               status |= do_swapoff(mnt_fs_get_source(fs),
+                                                    QUIET, CANONIC);
+
+                       mnt_free_iter(itr);
+               }
 
                /*
                 * Unswap stuff mentioned in /etc/fstab.
@@ -876,7 +834,7 @@ main_swapoff(int argc, char *argv[]) {
                        if (!special)
                                continue;
 
-                       if (!is_in_proc_swaps(special))
+                       if (!is_active_swap(special))
                                do_swapoff(special, QUIET, CANONIC);
                }
                fclose(fp);
@@ -888,6 +846,8 @@ main_swapoff(int argc, char *argv[]) {
 int
 main(int argc, char *argv[]) {
 
+       int status;
+
        setlocale(LC_ALL, "");
        bindtextdomain(PACKAGE, LOCALEDIR);
        textdomain(PACKAGE);
@@ -899,11 +859,17 @@ main(int argc, char *argv[]) {
                progname = p ? p+1 : argv[0];
        }
 
+       mnt_init_debug(0);
+
        if (streq(progname, "swapon"))
-               return main_swapon(argc, argv);
+               status = main_swapon(argc, argv);
        else if (streq(progname, "swapoff"))
-               return main_swapoff(argc, argv);
-
-       errx(EXIT_FAILURE, _("'%s' is unsupported program name "
+               status = main_swapoff(argc, argv);
+       else
+               errx(EXIT_FAILURE, _("'%s' is unsupported program name "
                        "(must be 'swapon' or 'swapoff')."), progname);
+
+       mnt_free_table(swaps);
+       mnt_free_cache(mntcache);
+       return status;
 }