Add function for listing system mount points

Add a mount_point_list() function that attempts to portably obtain
a list of system mount points and a struct to hold needed mount point
information.

Abort the transaction if we are unable to determine the mount points.

Signed-off-by: Allan McRae <allan@archlinux.org>
Signed-off-by: Dan McGee <dan@archlinux.org>

3 files changed, 160 insertions, 1 deletions

diff --git a/configure.ac b/configure.ac
index a8987a48..cf023002 100644
--- a/configure.ac
+++ b/configure.ac
@@ -169,7 +169,9 @@ AS_IF([test "x$with_fetch" != "xno"],
 AM_CONDITIONAL([HAVE_LIBFETCH], [test "x$ac_cv_lib_fetch_fetchParseURL" = "xyes"])
 
 # Checks for header files.
-AC_CHECK_HEADERS([fcntl.h glob.h libintl.h limits.h locale.h string.h strings.h sys/ioctl.h sys/param.h sys/statvfs.h sys/syslimits.h sys/time.h syslog.h wchar.h])
+AC_CHECK_HEADERS([fcntl.h glob.h libintl.h limits.h locale.h mntent.h string.h strings.h \
+                  sys/ioctl.h sys/mount.h sys/param.h sys/statvfs.h sys/syslimits.h \
+                  sys/time.h sys/types.h sys/ucred.h syslog.h wchar.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_C_INLINE
@@ -183,12 +185,30 @@ AC_STRUCT_DIRENT_D_TYPE
 
 # Checks for library functions.
 AC_FUNC_FORK
+AC_FUNC_GETMNTENT
 AC_FUNC_LSTAT_FOLLOWS_SLASHED_SYMLINK
 AC_FUNC_MKTIME
 AC_CHECK_FUNCS([geteuid realpath regcomp strcasecmp \
                 strndup strrchr strsep swprintf \
                 wcwidth uname])
 
+# Checks for getmntinfo and determines whether it uses statfs or statvfs
+AC_CHECK_FUNC(getmntinfo,
+	[AC_MSG_CHECKING(parameter style for getmntinfo)
+	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+# include <sys/param.h>
+# include <sys/mount.h>
+#if HAVE_SYS_UCRED_H
+#include <sys/ucred.h>
+#endif
+extern int getmntinfo (struct statfs **, int);
+		]], [])],
+		[AC_DEFINE(HAVE_GETMNTINFO_STATFS, [], [getmntinfo uses statfs])
+		AC_MSG_RESULT(statfs)],
+		[AC_DEFINE(HAVE_GETMNTINFO_STATVFS, [], [getmntinfo uses statvfs])
+		AC_MSG_RESULT(statvfs)])
+	])
+
 # Enable large file support if available
 AC_SYS_LARGEFILE
 
diff --git a/lib/libalpm/diskspace.c b/lib/libalpm/diskspace.c
index 31a2760d..a5beb84f 100644
--- a/lib/libalpm/diskspace.c
+++ b/lib/libalpm/diskspace.c
@@ -17,11 +17,130 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include "config.h"
+
+#if defined HAVE_GETMNTENT
+#include <mntent.h>
+#include <sys/statvfs.h>
+#elif defined HAVE_GETMNTINFO_STATFS
+#include <sys/param.h>
+#include <sys/mount.h>
+#if HAVE_SYS_UCRED_H
+#include <sys/ucred.h>
+#endif
+#elif defined HAVE_GETMNTINFO_STATVFS
+#include <sys/types.h>
+#include <sys/statvfs.h>
+#endif
+
 /* libalpm */
 #include "diskspace.h"
+#include "alpm_list.h"
+#include "util.h"
+#include "log.h"
+
+static alpm_list_t *mount_point_list()
+{
+	alpm_list_t *mount_points = NULL;
+	alpm_mountpoint_t *mp;
+
+#if defined HAVE_GETMNTENT
+	struct mntent *mnt;
+	FILE *fp;
+	struct statvfs fsp;
+
+	fp = setmntent(MOUNTED, "r");
+
+	if (fp == NULL) {
+		return NULL;
+	}
+
+	while((mnt = getmntent (fp))) {
+		if(statvfs(mnt->mnt_dir, &fsp) != 0) {
+			_alpm_log(PM_LOG_WARNING, "could not get filesystem information for %s\n", mnt->mnt_dir);
+			continue;
+		}
+
+		MALLOC(mp, sizeof(alpm_mountpoint_t), RET_ERR(PM_ERR_MEMORY, NULL));
+		mp->mount_dir = strdup(mnt->mnt_dir);
+
+		MALLOC(mp->fsp, sizeof(struct statvfs), RET_ERR(PM_ERR_MEMORY, NULL));
+		memcpy((void *)(mp->fsp), (void *)(&fsp), sizeof(struct statvfs));
+
+		mp->blocks_needed = 0;
+		mp->max_blocks_needed = 0;
+		mp->used = 0;
+
+		mount_points = alpm_list_add(mount_points, mp);
+	}
+
+	endmntent(fp);
+#elif defined HAVE_GETMNTINFO_STATFS
+	int entries;
+	struct statfs *fsp;
+
+	entries = getmntinfo(&fsp, MNT_NOWAIT);
+
+	if (entries < 0) {
+		return NULL;
+	}
+
+	for(; entries-- > 0; fsp++) {
+		MALLOC(mp, sizeof(alpm_mountpoint_t), RET_ERR(PM_ERR_MEMORY, NULL));
+		mp->mount_dir = strdup(fsp->f_mntonname);
+
+		MALLOC(mp->fsp, sizeof(struct statfs), RET_ERR(PM_ERR_MEMORY, NULL));
+		memcpy((void *)(mp->fsp), (void *)fsp, sizeof(struct statfs));
+
+		mp->blocks_needed = 0;
+		mp->max_blocks_needed = 0;
+
+		mount_points = alpm_list_add(mount_points, mp);
+	}
+#elif defined HAVE_GETMNTINFO_STATVFS
+	int entries;
+	struct statvfs *fsp;
+
+	entries = getmntinfo(&fsp, MNT_NOWAIT);
+
+	if (entries < 0) {
+		return NULL;
+	}
+
+	for (; entries-- > 0; fsp++) {
+		MALLOC(mp, sizeof(alpm_mountpoint_t), RET_ERR(PM_ERR_MEMORY, NULL));
+		mp->mount_dir = strdup(fsp->f_mntonname);
+
+		MALLOC(mp->fsp, sizeof(struct statvfs), RET_ERR(PM_ERR_MEMORY, NULL));
+		memcpy((void *)(mp->fsp), (void *)fsp, sizeof(struct statvfs));
+
+		mp->blocks_needed = 0;
+		mp->max_blocks_needed = 0;
+
+		mount_points = alpm_list_add(mount_points, mp);
+	}
+#endif
+
+	return(mount_points);
+}
 
 int _alpm_check_diskspace(pmtrans_t *trans, pmdb_t *db)
 {
+	alpm_list_t *mount_points;
+
+	mount_points = mount_point_list();
+	if(mount_points == NULL) {
+		_alpm_log(PM_LOG_ERROR, _("count not determine filesystem mount points"));
+		return -1;
+	}
+
+	for(i = mount_points; i; i = alpm_list_next(i)) {
+		alpm_mountpoint_t *data = i->data;
+		FREE(data->mount_dir);
+		FREE(data->fsp);
+	}
+	FREELIST(mount_points);
+
 	return 0;
 }
 
diff --git a/lib/libalpm/diskspace.h b/lib/libalpm/diskspace.h
index 69e39d8e..15ff2f67 100644
--- a/lib/libalpm/diskspace.h
+++ b/lib/libalpm/diskspace.h
@@ -20,8 +20,28 @@
 #ifndef _ALPM_DISKSPACE_H
 #define _ALPM_DISKSPACE_H
 
+#if defined HAVE_GETMNTINFO_STATFS
+#include <sys/mount.h>
+#else
+#include <sys/statvfs.h>
+#endif
+
 #include "alpm.h"
 
+typedef struct __alpm_mountpoint_t {
+	/* mount point information */
+	char *mount_dir;
+#if defined HAVE_GETMNTINFO_STATFS
+	struct statfs *fsp;
+#else
+	struct statvfs *fsp;
+#endif
+	/* storage for additional disk usage calculations */
+	long blocks_needed;
+	long max_blocks_needed;
+	int used;
+} alpm_mountpoint_t;
+
 int _alpm_check_diskspace(pmtrans_t *trans, pmdb_t *db);
 
 #endif /* _ALPM_DISKSPACE_H */