event*: Move proc parsing stuff to proc_parse

And prepare it for inotify (oh my...)
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

eventfd.c

@@ -15,7 +15,7 @@
 #include "compiler.h"
 #include "types.h"
 #include "eventfd.h"
-
+#include "proc_parse.h"
 #include "crtools.h"
 #include "image.h"
 #include "util.h"
@@ -60,44 +60,36 @@ out:
 	pr_img_tail(CR_FD_EVENTFD);
 }
 
-static int dump_one_eventfd(int lfd, u32 id, const struct fd_parms *p)
-{
-	int image_fd = fdset_fd(glob_fdset, CR_FD_EVENTFD);
-	struct eventfd_file_entry efe;
-	char buf[64];
-	char *pos;
-	int ret, fdinfo;
-
-	efe.id		= id;
-	efe.flags	= p->flags;
-	efe.fown	= p->fown;
-
-	snprintf(buf, sizeof(buf), "/proc/self/fdinfo/%d", lfd);
-	fdinfo = open(buf, O_RDONLY);
-	if (fdinfo < 0) {
-		pr_perror("Can't open  %d (%d)", p->fd, lfd);
-		return -1;
-	}
+struct eventfd_dump_arg {
+	u32 id;
+	const struct fd_parms *p;
+	bool dumped;
+};
 
-	ret = read(fdinfo, buf, sizeof(buf));
-	close(fdinfo);
+static int dump_eventfd_entry(union fdinfo_entries *e, void *arg)
+{
+	struct eventfd_dump_arg *da = arg;
+	struct eventfd_file_entry *efe = &e->efd;
 
-	if (ret <= 0) {
-		pr_perror("Reading eventfd from %d (%d) failed", p->fd, lfd);
+	if (da->dumped) {
+		pr_err("Several counters in a file?\n");
 		return -1;
 	}
 
-	pos = strstr(buf, "eventfd-count:");
-	if (!pos || !sscanf(pos, "eventfd-count: %lx", &efe.counter)) {
-		pr_err("Counter value is not found for %d (%d)\n", p->fd, lfd);
-		return -1;
-	}
+	da->dumped = true;
+	efe->id = da->id;
+	efe->flags = da->p->flags;
+	efe->fown = da->p->fown;
 
-	pr_info_eventfd("Dumping ", &efe);
-	if (write_img(image_fd, &efe))
-		return -1;
+	pr_info_eventfd("Dumping ", efe);
 
-	return 0;
+	return write_img(fdset_fd(glob_fdset, CR_FD_EVENTFD), efe);
+}
+
+static int dump_one_eventfd(int lfd, u32 id, const struct fd_parms *p)
+{
+	struct eventfd_dump_arg da = { .id = id, .p = p, };
+	return parse_fdinfo(lfd, FDINFO_EVENTFD, dump_eventfd_entry, &da);
 }
 
 static const struct fdtype_ops eventfd_ops = {

eventpoll.c

@@ -15,7 +15,7 @@
 #include "compiler.h"
 #include "types.h"
 #include "eventpoll.h"
-
+#include "proc_parse.h"
 #include "crtools.h"
 #include "image.h"
 #include "util.h"
@@ -92,59 +92,28 @@ out:
 	pr_img_tail(CR_FD_EVENTPOLL);
 }
 
+static int dump_eventpoll_entry(union fdinfo_entries *e, void *arg)
+{
+	struct eventpoll_tfd_entry *efd = &e->epl;
+
+	efd->id = *(u32 *)arg;
+	pr_info_eventpoll_tfd("Dumping: ", efd);
+	return write_img(fdset_fd(glob_fdset, CR_FD_EVENTPOLL_TFD), efd);
+}
+
 static int dump_one_eventpoll(int lfd, u32 id, const struct fd_parms *p)
 {
-	int image_fd = fdset_fd(glob_fdset, CR_FD_EVENTPOLL);
-	int image_tfd = fdset_fd(glob_fdset, CR_FD_EVENTPOLL_TFD);
 	struct eventpoll_file_entry e;
-	struct eventpoll_tfd_entry efd;
-	char buf[PAGE_SIZE], *tok;
-	int ret, fdinfo;
-
-	snprintf(buf, sizeof(buf), "/proc/self/fdinfo/%d", lfd);
-	fdinfo = open(buf, O_RDONLY);
-	if (fdinfo < 0) {
-		pr_perror("Can't open %d (%d)", p->fd, lfd);
-		return -1;
-	}
 
-	ret = read(fdinfo, buf, sizeof(buf));
-	close(fdinfo);
-	if (ret <= 0) {
-		pr_perror("Reading eventpoll from %d (%d) failed", p->fd, lfd);
-		return -1;
-	}
-
-	e.id	= id;
-	e.flags	= p->flags;
-	e.fown	= p->fown;
+	e.id = id;
+	e.flags = p->flags;
+	e.fown = p->fown;
 
 	pr_info_eventpoll("Dumping ", &e);
-	if (write_img(image_fd, &e))
+	if (write_img(fdset_fd(glob_fdset, CR_FD_EVENTPOLL), &e))
 		return -1;
 
-	tok = strstr(buf, "tfd:");
-	if (!tok)
-		return 0;
-
-	tok = strtok(tok, "\n");
-	while (tok) {
-		efd.id = id;
-		if (sscanf(tok, "tfd: %8d events: %8x data: %16lx",
-			&efd.tfd, &efd.events, &efd.data) != 3)
-			goto parsing_err;
-		tok = strtok(NULL, "\n");
-
-		pr_info_eventpoll_tfd("Dumping: ", &efd);
-		if (write_img(image_tfd, &efd))
-			return -1;
-	}
-
-	return 0;
-
-parsing_err:
-	pr_err("Parsing error %d (%d)", p->fd, lfd);
-	return -1;
+	return parse_fdinfo(lfd, FDINFO_EVENTPOLL, dump_eventpoll_entry, &id);
 }
 
 static const struct fdtype_ops eventpoll_ops = {

include/proc_parse.h

@@ -3,7 +3,7 @@
 
 #include <sys/types.h>
 #include "types.h"
-
+#include "image.h"
 #include "list.h"
 
 #define PROC_TASK_COMM_LEN	32
@@ -117,4 +117,12 @@ extern int parse_pid_stat_small(pid_t pid, struct proc_pid_stat_small *s);
 extern int parse_smaps(pid_t pid, struct list_head *vma_area_list, bool use_map_files);
 extern int parse_pid_status(pid_t pid, struct proc_status_creds *);
 
+union fdinfo_entries {
+	struct eventfd_file_entry efd;
+	struct eventpoll_tfd_entry epl;
+};
+
+extern int parse_fdinfo(int fd, int type,
+		int (*cb)(union fdinfo_entries *e, void *arg), void *arg);
+
 #endif /* PROC_PARSE_H__ */

proc_parse.c

@@ -675,3 +675,59 @@ err:
 	}
 	goto out;
 }
+
+#define fdinfo_field(str, field)	!strncmp(str, field":", sizeof(field))
+
+int parse_fdinfo(int fd, int type,
+		int (*cb)(union fdinfo_entries *e, void *arg), void *arg)
+{
+	FILE *f;
+	char str[256];
+
+	sprintf(str, "/proc/self/fdinfo/%d", fd);
+	f = fopen(str, "r");
+	if (!f) {
+		pr_perror("Can't open fdinfo to parse");
+		return -1;
+	}
+
+	while (fgets(str, sizeof(str), f)) {
+		int ret;
+		union fdinfo_entries entry;
+
+		if (fdinfo_field(str, "pos") || fdinfo_field(str, "counter"))
+			continue;
+
+		if (fdinfo_field(str, "eventfd-count")) {
+			if (type != FDINFO_EVENTFD)
+				goto parse_err;
+			ret = sscanf(str, "eventfd-count: %lx",
+					&entry.efd.counter);
+			if (ret != 1)
+				goto parse_err;
+			ret = cb(&entry, arg);
+			if (ret)
+				return ret;
+			continue;
+		}
+		if (fdinfo_field(str, "tfd")) {
+			if (type != FDINFO_EVENTPOLL)
+				goto parse_err;
+			ret = sscanf(str, "tfd: %d events: %x data: %lx",
+					&entry.epl.tfd, &entry.epl.events, &entry.epl.data);
+			if (ret != 3)
+				goto parse_err;
+			ret = cb(&entry, arg);
+			if (ret)
+				return ret;
+			continue;
+		}
+	}
+
+	fclose(f);
+	return 0;
+
+parse_err:
+	pr_perror("%s: error parsing [%s] for %d\n", __func__, str, type);
+	return -1;
+}