[PATCH 12/14] xfsprogs: make fsr use mntinfo when there is no mntent

[Jan Tulak <jtulak@xxxxxxxxxx>]

For what fsr needs, mntinfo can be used instead of mntent.
Custom mntent struct is used to avoid too big ifdefs:
We only change few lines and the rest of the code can still
use mntent as before.

Signed-off-by: Jan Tulak <jtulak@xxxxxxxxxx>
---
 fsr/Makefile     |  8 +++++++
 fsr/xfs_fsr.c    | 69 ++++++++++++++++++++++++++++++++++++++++++++++++--------
 include/darwin.h | 20 ++++++++++++++++
 3 files changed, 87 insertions(+), 10 deletions(-)

diff --git a/fsr/Makefile b/fsr/Makefile
index a9d1bf6..d3521b2 100644
--- a/fsr/Makefile
+++ b/fsr/Makefile
@@ -9,6 +9,14 @@ LTCOMMAND = xfs_fsr
 CFILES = xfs_fsr.c
 LLDLIBS = $(LIBHANDLE)
 
+ifeq ($(HAVE_GETMNTENT),yes)
+LCFLAGS += -DHAVE_GETMNTENT
+endif
+
+ifeq ($(HAVE_GETMNTINFO),yes)
+LCFLAGS += -DHAVE_GETMNTINFO
+endif
+
 default: depend $(LTCOMMAND)
 
 include $(BUILDRULES)
diff --git a/fsr/xfs_fsr.c b/fsr/xfs_fsr.c
index 5f95cdc..ff791d3 100644
--- a/fsr/xfs_fsr.c
+++ b/fsr/xfs_fsr.c
@@ -32,8 +32,10 @@
 #include <sys/statvfs.h>
 #include <sys/xattr.h>
 
-#ifdef HAVE_MNTENT
+#if defined(HAVE_GETMNTENT)
 #  include <mntent.h>
+#elif defined(HAVE_GETMNTINFO)
+#  include <sys/mount.h>
 #endif
 
 #ifdef __APPLE__
@@ -191,9 +193,10 @@ find_mountpoint(char *mtab, char *argname, struct stat64 
*sb)
 {
        struct mntent *t;
        struct stat64 ms;
-       FILE *mtabp;
        char *mntp = NULL;
 
+#if defined(HAVE_GETMNTENT)
+       FILE *mtabp;
        mtabp = setmntent(mtab, "r");
        if (!mtabp) {
                fprintf(stderr, _("%s: cannot read %s\n"),
@@ -202,6 +205,27 @@ find_mountpoint(char *mtab, char *argname, struct stat64 
*sb)
        }
 
        while ((t = getmntent(mtabp))) {
+#elif defined(HAVE_GETMNTINFO)
+       struct statfs   *stats;
+       int error, i, count;
+       // because "t" is a pointer, but we don't need to use
+       // malloc for this usage
+       struct mntent t_tmp;
+       t = &t_tmp;
+
+               
+       error = 0;
+       if ((count = getmntinfo(&stats, 0)) < 0) {
+               fprintf(stderr, _("%s: getmntinfo() failed: %s\n"),
+                               progname, strerror(errno));
+               return 0;
+       }
+
+       for (i = 0; i < count; i++) {
+               mntinfo2mntent(&stats[i], t);
+#else
+# error "How do I extract info about mounted filesystems on this platform?"
+#endif
                if (S_ISDIR(sb->st_mode)) {             /* mount point */
                        if (stat64(t->mnt_dir, &ms) < 0)
                                continue;
@@ -233,10 +257,11 @@ find_mountpoint(char *mtab, char *argname, struct stat64 
*sb)
                break;
        }
 
+#if defined(HAVE_GETMNTENT)
        endmntent(mtabp);
+#endif
        return mntp;
 }
-
 int
 main(int argc, char **argv)
 {
@@ -411,18 +436,11 @@ usage(int ret)
 static void
 initallfs(char *mtab)
 {
-       FILE *fp;
        struct mntent *mp;
        int mi;
        char *cp;
        struct stat64 sb;
 
-       fp = setmntent(mtab, "r");
-       if (fp == NULL) {
-               fsrprintf(_("could not open mtab file: %s\n"), mtab);
-               exit(1);
-       }
-
        /* malloc a number of descriptors, increased later if needed */
        if (!(fsbase = (fsdesc_t *)malloc(fsbufsize * sizeof(fsdesc_t)))) {
                fsrprintf(_("out of memory: %s\n"), strerror(errno));
@@ -433,7 +451,36 @@ initallfs(char *mtab)
        /* find all rw xfs file systems */
        mi = 0;
        fs = fsbase;
+
+#if defined(HAVE_GETMNTENT)
+       FILE *fp;
+       fp = setmntent(mtab, "r");
+       if (fp == NULL) {
+               fsrprintf(_("could not open mtab file: %s\n"), mtab);
+               exit(1);
+       }
+
        while ((mp = getmntent(fp))) {
+#elif defined(HAVE_GETMNTINFO)
+       struct statfs   *stats;
+       int error, i, count;
+       // because "t" is a pointer, but we don't need to use
+       // malloc for this usage
+       struct mntent mp_tmp;
+       mp = &mp_tmp;
+       error = 0;
+       if ((count = getmntinfo(&stats, 0)) < 0) {
+               fprintf(stderr, _("%s: getmntinfo() failed: %s\n"),
+                               progname, strerror(errno));
+               exit(1);
+       }
+
+       for (i = 0; i < count; i++) {
+               mntinfo2mntent(&stats[i], mp);
+#else
+# error "How do I extract info about mounted filesystems on this platform?"
+#endif
+
                int rw = 0;
 
                if (strcmp(mp->mnt_type, MNTTYPE_XFS ) != 0 ||
@@ -485,7 +532,9 @@ initallfs(char *mtab)
        }
        numfs = mi;
        fsend = (fsbase + numfs);
+#if defined(HAVE_GETMNTENT)
        endmntent(fp);
+#endif
        if (numfs == 0) {
                fsrprintf(_("no rw xfs file systems in mtab: %s\n"), mtab);
                exit(0);
diff --git a/include/darwin.h b/include/darwin.h
index 288ad1f..0313f46 100644
--- a/include/darwin.h
+++ b/include/darwin.h
@@ -218,7 +218,27 @@ static inline int timer_gettime (timer_t timerid, struct 
itimerspec *value)
 
 /* FSR */
 
+#  include <sys/mount.h>
+#  include <sys/param.h>
+#include <sys/ucred.h>
+#include <errno.h>
 #define statvfs64 statfs
 #define                _PATH_MOUNTED   "/etc/mtab"
 
+struct mntent
+{
+       char *mnt_fsname;
+       char *mnt_dir;
+       char *mnt_type;
+       char *mnt_opts;
+       int mnt_freq;
+       int mnt_passno;
+};
+
+static inline void mntinfo2mntent (struct statfs * stats, struct mntent * mnt) 
{
+       mnt->mnt_fsname = stats->f_mntfromname;
+       mnt->mnt_dir = stats->f_mntonname;
+       mnt->mnt_type = stats->f_fstypename;
+}
+
 #endif /* __XFS_DARWIN_H__ */
-- 
2.4.3