lslocks: (refactor) use a tree for storing lock information extracted from /proc...

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

diff --git a/misc-utils/lslocks.c b/misc-utils/lslocks.c
index 155819f8dc8f6c2e64f0b8d7d4f929df7e94a9a8..a8613bed19979057aafb9a442b82a57f69caf376 100644 (file)
--- a/misc-utils/lslocks.c
+++ b/misc-utils/lslocks.c
@@ -32,6 +32,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <stdbool.h>
+#include <search.h>
 
 #include <libmount.h>
 #include <libsmartcols.h>
@@ -117,6 +118,52 @@ struct lock {
        int id;
 };
 
+struct lock_tnode {
+       dev_t dev;
+       ino_t inode;
+
+       struct list_head chain;
+};
+
+static int lock_tnode_compare(const void *a, const void *b)
+{
+       struct lock_tnode *anode = ((struct lock_tnode *)a);
+       struct lock_tnode *bnode = ((struct lock_tnode *)b);
+
+       if (anode->dev > bnode->dev)
+               return 1;
+       else if (anode->dev < bnode->dev)
+               return -1;
+
+       if (anode->inode > bnode->inode)
+               return 1;
+       else if (anode->inode < bnode->inode)
+               return -1;
+
+       return 0;
+}
+
+static void add_to_tree(void *troot, struct lock *l)
+{
+       struct lock_tnode tmp = { .dev = l->dev, .inode = l->inode, };
+       struct lock_tnode **head = tfind(&tmp, troot, lock_tnode_compare);
+       struct lock_tnode *new_head;
+
+       if (head) {
+               list_add(&l->locks, &(*head)->chain);
+               return;
+       }
+
+       new_head = xmalloc(sizeof(*l));
+       new_head->dev = l->dev;
+       new_head->inode = l->inode;
+       INIT_LIST_HEAD(&new_head->chain);
+       if (tsearch(new_head, troot, lock_tnode_compare) == NULL)
+               errx(EXIT_FAILURE, _("failed to allocate memory"));
+
+       list_add(&l->locks, &new_head->chain);
+}
+
 static void rem_lock(struct lock *lock)
 {
        if (!lock)
@@ -245,11 +292,16 @@ struct override_info {
        const char *cmdname;
 };
 
-static void patch_lock(struct lock *l, struct list_head *fallback)
+static void patch_lock(struct lock *l, void *fallback)
 {
+       struct lock_tnode tmp = { .dev = l->dev, .inode = l->inode, };
+       struct lock_tnode **head = tfind(&tmp, fallback, lock_tnode_compare);
        struct list_head *p;
 
-       list_for_each(p, fallback) {
+       if (!head)
+               return;
+
+       list_for_each(p, &(*head)->chain) {
                struct lock *m = list_entry(p, struct lock, locks);
                if (l->start == m->start &&
                    l->end == m->end &&
@@ -272,7 +324,7 @@ static void add_to_list(void *locks, struct lock *l)
        list_add(&l->locks, locks);
 }
 
-static struct lock *get_lock(char *buf, struct override_info *oinfo, struct list_head *fallback)
+static struct lock *get_lock(char *buf, struct override_info *oinfo, void *fallback)
 {
        int i;
        char *tok = NULL;
@@ -469,7 +521,7 @@ static int get_pids_locks(void *locks, void (*add_lock)(void *, struct lock *))
        return rc;
 }
 
-static int get_proc_locks(void *locks, void (*add_lock)(void *, struct lock *), struct list_head *fallback)
+static int get_proc_locks(void *locks, void (*add_lock)(void *, struct lock *), void *fallback)
 {
        FILE *fp;
        char buf[PATH_MAX];
@@ -622,6 +674,14 @@ static void rem_locks(struct list_head *locks)
        }
 }
 
+static void rem_tnode(void *node)
+{
+       struct lock_tnode *tnode = node;
+
+       rem_locks(&tnode->chain);
+       free(node);
+}
+
 static int show_locks(struct list_head *locks, pid_t target_pid)
 {
        int rc = 0;
@@ -730,7 +790,8 @@ static void __attribute__((__noreturn__)) usage(void)
 int main(int argc, char *argv[])
 {
        int c, rc = 0;
-       struct list_head proc_locks, pid_locks;
+       struct list_head proc_locks;
+       void *pid_locks = NULL;
        char *outarg = NULL;
        enum {
                OPT_OUTPUT_ALL = CHAR_MAX + 1
@@ -807,7 +868,6 @@ int main(int argc, char *argv[])
        }
 
        INIT_LIST_HEAD(&proc_locks);
-       INIT_LIST_HEAD(&pid_locks);
 
        if (!ncolumns) {
                /* default columns */
@@ -832,13 +892,13 @@ int main(int argc, char *argv[])
         * of /proc/$pid/fdinfo/$fd as fallback information.
         * get_proc_locks() used the fallback information if /proc/locks
         * doesn't provides enough information or provides staled information. */
-       get_pids_locks(&pid_locks, add_to_list);
+       get_pids_locks(&pid_locks, add_to_tree);
        rc = get_proc_locks(&proc_locks, add_to_list, &pid_locks);
 
        if (!rc && !list_empty(&proc_locks))
                rc = show_locks(&proc_locks, target_pid);
 
-       rem_locks(&pid_locks);
+       tdestroy(pid_locks, rem_tnode);
        rem_locks(&proc_locks);
 
        mnt_unref_table(tab);