libmount: add mnt_tab_find_pair()

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

diff --git a/shlibs/mount/src/mount.h.in b/shlibs/mount/src/mount.h.in
index 3890dd4f283d8f66e1100e4e72a4ce4906f9c846..43f81080d2677b15d93eecda7e606b2dd8ae63ab 100644 (file)
--- a/shlibs/mount/src/mount.h.in
+++ b/shlibs/mount/src/mount.h.in
@@ -276,6 +276,8 @@ extern mnt_fs *mnt_tab_find_srcpath(mnt_tab *tb, const char *path, int direction
 extern mnt_fs *mnt_tab_find_tag(mnt_tab *tb, const char *tag,
                                const char *val, int direction);
 extern mnt_fs *mnt_tab_find_source(mnt_tab *tb, const char *source, int direction);
+extern mnt_fs *mnt_tab_find_pair(mnt_tab *tb, const char *source,
+                               const char *target, int direction);
 
 extern int mnt_tab_find_next_fs(mnt_tab *tb, mnt_iter *itr,
                        int (*match_func)(mnt_fs *, void *), void *userdata,

diff --git a/shlibs/mount/src/mount.sym b/shlibs/mount/src/mount.sym
index 5f527605ef865d905fd342a4abee80acc4ee8991..f97d0048bbe8dc0bb2a659c23f4651566911b65c 100644 (file)
--- a/shlibs/mount/src/mount.sym
+++ b/shlibs/mount/src/mount.sym
@@ -94,6 +94,7 @@ global:
        mnt_split_optstr;
        mnt_tab_add_fs;
        mnt_tab_find_next_fs;
+       mnt_tab_find_pair;
        mnt_tab_find_source;
        mnt_tab_find_srcpath;
        mnt_tab_find_tag;

diff --git a/shlibs/mount/src/tab.c b/shlibs/mount/src/tab.c
index b30bc00d0ccaaede3b0ec3fba848b69cab0bb956..2b680270851d7342b0400723675423586aa3bdd0 100644 (file)
--- a/shlibs/mount/src/tab.c
+++ b/shlibs/mount/src/tab.c
@@ -650,6 +650,45 @@ mnt_fs *mnt_tab_find_source(mnt_tab *tb, const char *source, int direction)
        return fs;
 }
 
+/**
+ * mnt_tab_find_pair
+ * @tb: tab pointer
+ * @source: TAG or path
+ * @target: mountpoint
+ * @direction: MNT_ITER_{FORWARD,BACKWARD}
+ *
+ * This function is implemented by mnt_fs_match_source() and
+ * mnt_fs_match_target() functions. It means that this is more expensive that
+ * others mnt_tab_find_* function, because every @tab entry is fully evaluated.
+ *
+ * Returns: a tab entry or NULL.
+ */
+mnt_fs *mnt_tab_find_pair(mnt_tab *tb, const char *source,
+                       const char *target, int direction)
+{
+       mnt_fs *fs = NULL;
+       mnt_iter itr;
+
+       assert(tb);
+       assert(source);
+       assert(target);
+
+       if (!tb || !source || !target)
+               return NULL;
+
+       DBG(TAB, mnt_debug_h(tb, "lookup SOURCE: %s TARGET: %s", source, target));
+
+       mnt_reset_iter(&itr, direction);
+       while(mnt_tab_next_fs(tb, &itr, &fs) == 0) {
+
+               if (mnt_fs_match_target(fs, target, tb->cache) &&
+                   mnt_fs_match_source(fs, source, tb->cache))
+                       return fs;
+       }
+
+       return NULL;
+}
+
 #ifdef TEST_PROGRAM
 
 static int parser_errcb(mnt_tab *tb, const char *filename, int line, int flag)
@@ -682,6 +721,7 @@ int test_copy_fs(struct mtest *ts, int argc, char *argv[])
 {
        mnt_tab *tb;
        mnt_fs *fs;
+       int rc = -1;
 
        tb = create_tab(argv[1]);
        if (!tb)
@@ -689,28 +729,30 @@ int test_copy_fs(struct mtest *ts, int argc, char *argv[])
 
        fs = mnt_tab_find_target(tb, "/", MNT_ITER_FORWARD);
        if (!fs)
-               goto err;
+               goto done;
 
        printf("ORIGINAL:\n");
        mnt_fs_print_debug(fs, stdout);
 
        fs = mnt_copy_fs(fs);
        if (!fs)
-               goto err;
+               goto done;
 
        printf("COPY:\n");
        mnt_fs_print_debug(fs, stdout);
        mnt_free_fs(fs);
-err:
+       rc = 0;
+done:
        mnt_free_tab(tb);
-       return 0;
+       return rc;
 }
 
 int test_parse(struct mtest *ts, int argc, char *argv[])
 {
-       mnt_tab *tb;
-       mnt_iter *itr;
+       mnt_tab *tb = NULL;
+       mnt_iter *itr = NULL;
        mnt_fs *fs;
+       int rc = -1;
 
        tb = create_tab(argv[1]);
        if (!tb)
@@ -718,38 +760,40 @@ int test_parse(struct mtest *ts, int argc, char *argv[])
 
        itr = mnt_new_iter(MNT_ITER_FORWARD);
        if (!itr)
-               goto err;
+               goto done;
 
        while(mnt_tab_next_fs(tb, itr, &fs) == 0)
                mnt_fs_print_debug(fs, stdout);
-err:
+       rc = 0;
+done:
        mnt_free_iter(itr);
        mnt_free_tab(tb);
-       return 0;
+       return rc;
 }
 
 int test_find(struct mtest *ts, int argc, char *argv[], int dr)
 {
        mnt_tab *tb;
        mnt_fs *fs = NULL;
-       mnt_cache *mpc;
+       mnt_cache *mpc = NULL;
        const char *file, *find, *what;
+       int rc = -1;
 
        if (argc != 4) {
                fprintf(stderr, "try --help\n");
-               goto err;
+               return -EINVAL;
        }
 
        file = argv[1], find = argv[2], what = argv[3];
 
        tb = create_tab(file);
        if (!tb)
-               goto err;
+               goto done;
 
        /* create a cache for canonicalized paths */
        mpc = mnt_new_cache();
        if (!mpc)
-               goto err;
+               goto done;
        mnt_tab_set_cache(tb, mpc);
 
        if (strcasecmp(find, "source") == 0)
@@ -770,12 +814,12 @@ int test_find(struct mtest *ts, int argc, char *argv[], int dr)
                }
                printf("|%s|%s\n", mnt_fs_get_target(fs),
                                mnt_fs_get_optstr(fs));
+               rc = 0;
        }
+done:
        mnt_free_tab(tb);
        mnt_free_cache(mpc);
-       return 0;
-err:
-       return -1;
+       return rc;
 }
 
 int test_find_bw(struct mtest *ts, int argc, char *argv[])
@@ -788,12 +832,34 @@ int test_find_fw(struct mtest *ts, int argc, char *argv[])
        return test_find(ts, argc, argv, MNT_ITER_FORWARD);
 }
 
+int test_find_pair(struct mtest *ts, int argc, char *argv[])
+{
+       mnt_tab *tb;
+       mnt_fs *fs;
+       int rc = -1;
+
+       tb = create_tab(argv[1]);
+       if (!tb)
+               return -1;
+
+       fs = mnt_tab_find_pair(tb, argv[2], argv[3], MNT_ITER_FORWARD);
+       if (!fs)
+               goto done;
+
+       mnt_fs_print_debug(fs, stdout);
+       rc = 0;
+done:
+       mnt_free_tab(tb);
+       return rc;
+}
+
 int main(int argc, char *argv[])
 {
        struct mtest tss[] = {
        { "--parse",    test_parse,        "<file>  parse and print tab" },
        { "--find-forward",  test_find_fw, "<file> <source|target> <string>" },
        { "--find-backward", test_find_bw, "<file> <source|target> <string>" },
+       { "--find-pair",     test_find_pair, "<file> <source> <target>" },
        { "--copy-fs",       test_copy_fs, "<file>  copy root FS from the file" },
        { NULL }
        };