lsfd: small cleanup to mountinfo/nodev code

* use path_cxt to open mountinfo (so remove open_mountinfo())
* move all nodev code to one place
* merge add_nodev() to add_nodevs()

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

diff --git a/misc-utils/lsfd.c b/misc-utils/lsfd.c
index a62cc4e9b73788568207a8c9409db5b1b4926efd..68a77aeef3ff39e16d6e31acd6fc9e230836ffa5 100644 (file)
--- a/misc-utils/lsfd.c
+++ b/misc-utils/lsfd.c
@@ -53,8 +53,6 @@ static int kcmp(pid_t pid1, pid_t pid2, int type,
 #include "lsfd.h"
 
 
-static void add_nodev(unsigned long minor, const char *filesystem);
-
 /*
  * /proc/$pid/maps entries
  */
@@ -323,34 +321,6 @@ static void free_proc(struct proc *proc)
        free(proc);
 }
 
-static struct nodev* new_nodev(unsigned long minor, const char *filesystem)
-{
-       struct nodev *nodev = xcalloc(1, sizeof(*nodev));
-
-       INIT_LIST_HEAD(&nodev->nodevs);
-       nodev->minor = minor;
-       nodev->filesystem = xstrdup(filesystem);
-
-       return nodev;
-}
-
-static void free_nodev(struct nodev *nodev)
-{
-       free(nodev->filesystem);
-       free(nodev);
-}
-
-static void initialize_nodevs(void)
-{
-       for (int i = 0; i < NODEV_TABLE_SIZE; i++)
-               INIT_LIST_HEAD(&nodev_table.tables[i]);
-}
-
-static void finalize_nodevs(void)
-{
-       for (int i = 0; i < NODEV_TABLE_SIZE; i++)
-               list_free(&nodev_table.tables[i], struct nodev, nodevs, free_nodev);
-}
 
 
 
@@ -693,19 +663,60 @@ static void collect_namespace_files(struct proc *proc)
                               ARRAY_SIZE(namespace_assocs));
 }
 
-static FILE *open_mountinfo(pid_t pid, pid_t tid)
+static struct nodev *new_nodev(unsigned long minor, const char *filesystem)
 {
-       return fopenf("r", "/proc/%d/task/%d/mountinfo", pid, tid);
+       struct nodev *nodev = xcalloc(1, sizeof(*nodev));
+
+       INIT_LIST_HEAD(&nodev->nodevs);
+       nodev->minor = minor;
+       nodev->filesystem = xstrdup(filesystem);
+
+       return nodev;
 }
 
-static void add_nodevs(FILE *mountinfo_fp)
+static void free_nodev(struct nodev *nodev)
 {
-       /* This can be very long.
-          A line in mountinfo can have more than 3 paths. */
+       free(nodev->filesystem);
+       free(nodev);
+}
+
+static void initialize_nodevs(void)
+{
+       for (int i = 0; i < NODEV_TABLE_SIZE; i++)
+               INIT_LIST_HEAD(&nodev_table.tables[i]);
+}
+
+static void finalize_nodevs(void)
+{
+       for (int i = 0; i < NODEV_TABLE_SIZE; i++)
+               list_free(&nodev_table.tables[i], struct nodev, nodevs, free_nodev);
+}
+
+const char *get_nodev_filesystem(unsigned long minor)
+{
+       struct list_head *n;
+       int slot = minor % NODEV_TABLE_SIZE;
+
+       list_for_each (n, &nodev_table.tables[slot]) {
+               struct nodev *nodev = list_entry(n, struct nodev, nodevs);
+               if (nodev->minor == minor)
+                       return nodev->filesystem;
+       }
+       return NULL;
+}
+
+static void add_nodevs(FILE *mnt)
+{
+       /* This can be very long. A line in mountinfo can have more than 3
+        * paths. */
        char line[PATH_MAX * 3 + 256];
-       while (fgets(line, sizeof(line), mountinfo_fp)) {
+
+       while (fgets(line, sizeof(line), mnt)) {
                unsigned long major, minor;
                char filesystem[256];
+               struct nodev *nodev;
+               int slot;
+
 
                /* 23 61 0:22 / /sys rw,nosuid,nodev,noexec,relatime shared:2 - sysfs sysfs rw,seclabel */
                if(sscanf(line, "%*d %*d %lu:%lu %*s %*s %*s %*[^-] - %s %*[^\n]",
@@ -717,12 +728,16 @@ static void add_nodevs(FILE *mountinfo_fp)
 
                if (major != 0)
                        continue;
+               if (get_nodev_filesystem(minor))
+                       continue;
 
-               add_nodev(minor, filesystem);
+               nodev = new_nodev(minor, filesystem);
+               slot = minor % NODEV_TABLE_SIZE;
+
+               list_add_tail(&nodev->nodevs, &nodev_table.tables[slot]);
        }
 }
 
-
 static void fill_column(struct proc *proc,
                        struct file *file,
                        struct libscols_line *ln,
@@ -890,39 +905,13 @@ FILE *fopenf(const char *mode, const char *format, ...)
        return fopen(path, mode);
 }
 
-static void add_nodev(unsigned long minor, const char *filesystem)
-{
-       struct nodev *nodev;
-       int slot;
-
-       if (get_nodev_filesystem(minor))
-               return;
-
-       nodev = new_nodev(minor, filesystem);
-       slot = minor % NODEV_TABLE_SIZE;
-
-       list_add_tail(&nodev->nodevs, &nodev_table.tables[slot]);
-}
-
-const char *get_nodev_filesystem(unsigned long minor)
-{
-       struct list_head *n;
-       int slot = minor % NODEV_TABLE_SIZE;
-
-       list_for_each (n, &nodev_table.tables[slot]) {
-               struct nodev *nodev = list_entry(n, struct nodev, nodevs);
-               if (nodev->minor == minor)
-                       return nodev->filesystem;
-       }
-       return NULL;
-}
 
 static void read_process(struct lsfd_control *ctl, struct path_cxt *pc,
                         pid_t pid, struct proc *leader)
 {
        char buf[BUFSIZ];
        struct proc *proc;
-       FILE *mountinfo_fp;
+       FILE *mnt;
 
        if (procfs_process_init_path(pc, pid) != 0)
                return;
@@ -939,11 +928,14 @@ static void read_process(struct lsfd_control *ctl, struct path_cxt *pc,
 
        collect_namespace_files(proc);
 
-       mountinfo_fp = open_mountinfo(proc->leader->pid,
-                                     proc->pid);
-       if (mountinfo_fp) {
-               add_nodevs(mountinfo_fp);
-               fclose(mountinfo_fp);
+       /* TODO: parse mountinfo only when process uses not-yet-known
+        *       mount namespace. Parse mountinfo for each process is
+        *       extremly expensive.
+        */
+       mnt = ul_path_fopen(pc, "r", "mountinfo");
+       if (mnt) {
+               add_nodevs(mnt);
+               fclose(mnt);
        }
 
        /* If kcmp is not available,