wdctl: sysfs open refactoring

Let's make the sysfs handler usable in more functions.

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

diff --git a/sys-utils/wdctl.c b/sys-utils/wdctl.c
index d9abea8addcfbecad3ea0241d231e5a5c866c322..6081c42ac8b750fbd22cbab24acc17ad3dbde77c 100644 (file)
--- a/sys-utils/wdctl.c
+++ b/sys-utils/wdctl.c
@@ -109,6 +109,7 @@ static int ncolumns;
 
 struct wd_device {
        const char      *devpath;
+       struct path_cxt *sysfs;
 
        int             timeout;
        int             timeleft;
@@ -123,7 +124,8 @@ struct wd_device {
        unsigned int    has_timeout : 1,
                        has_timeleft : 1,
                        has_pretimeout : 1,
-                       has_nowayout : 1;
+                       has_nowayout : 1,
+                       no_sysfs : 1;
 };
 
 struct wd_control {
@@ -472,21 +474,22 @@ static int read_watchdog_from_device(struct wd_device *wd)
        return 0;
 }
 
-/* Returns: <0 error, 0 success, 1 unssuported */
-static int read_watchdog_from_sysfs(struct wd_device *wd)
+static struct path_cxt *get_sysfs(struct wd_device *wd)
 {
        struct path_cxt *sys;
        struct stat st;
-       int rc;
 
-       rc = stat(wd->devpath, &st);
-       if (rc != 0)
-               return rc;
+       if (wd->no_sysfs)
+               return NULL;
+       if (wd->sysfs)
+               return wd->sysfs;
+       if (stat(wd->devpath, &st) != 0)
+               goto nosysfs;
 
        sys = ul_new_path(_PATH_SYS_DEVCHAR "/%u:%u",
                        major(st.st_rdev), minor(st.st_rdev));
        if (!sys)
-               return -ENOMEM;
+               return NULL;
 
        if (ul_path_get_dirfd(sys) < 0)
                goto nosysfs;           /* device not in /sys */
@@ -494,6 +497,22 @@ static int read_watchdog_from_sysfs(struct wd_device *wd)
        if (ul_path_access(sys, F_OK, "identity") != 0)
                goto nosysfs;           /* no info in /sys (old miscdev?) */
 
+       wd->sysfs = sys;
+       return sys;
+nosysfs:
+       wd->no_sysfs = 1;
+       return NULL;
+}
+
+/* Returns: <0 error, 0 success, 1 unssuported */
+static int read_watchdog_from_sysfs(struct wd_device *wd)
+{
+       struct path_cxt *sys;
+
+       sys = get_sysfs(wd);
+       if (!sys)
+               return 1;
+
        ul_path_read_buffer(sys, (char *) wd->ident.identity, sizeof(wd->ident.identity), "identity");
 
        ul_path_scanf(sys, "status", "%x", &wd->status);
@@ -508,11 +527,7 @@ static int read_watchdog_from_sysfs(struct wd_device *wd)
        if (ul_path_read_s32(sys, &wd->timeleft, "timeleft") == 0)
                wd->has_timeleft = 1;
 
-       ul_unref_path(sys);
        return 0;
-nosysfs:
-       ul_unref_path(sys);
-       return 1;
 }
 
 static int read_watchdog(struct wd_device *wd)
@@ -527,6 +542,8 @@ static int read_watchdog(struct wd_device *wd)
                return -1;
        }
 
+       ul_unref_path(wd->sysfs);
+       wd->sysfs = NULL;
        return 0;
 }