pipe: Don't intermix pipe and fifo data when dumping

The existing code checks for ID to be already dumped. But pipe and fifo may have the same ID
since they reside on different filesystems.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

fifo.c

@@ -35,6 +35,7 @@ struct fifo_info {
 };
 
 static LIST_HEAD(fifo_head);
+static struct pipe_data_dump pd_fifo = { .img_type = CR_FD_FIFO_DATA, };
 
 static int dump_one_fifo(int lfd, u32 id, const struct fd_parms *p)
 {
@@ -58,7 +59,7 @@ static int dump_one_fifo(int lfd, u32 id, const struct fd_parms *p)
 	if (write_img(img, &e) < 0)
 		return -1;
 
-	return dump_one_pipe_data(CR_FD_FIFO_DATA, lfd, p);
+	return dump_one_pipe_data(&pd_fifo, lfd, p);
 }
 
 static const struct fdtype_ops fifo_ops = {

include/pipes.h

@@ -5,7 +5,15 @@ extern void mark_pipe_master(void);
 int dump_pipe(struct fd_parms *p, int lfd,
 			     const struct cr_fdset *cr_fdset);
 
-extern int dump_one_pipe_data(int img_type, int lfd, const struct fd_parms *p);
+#define NR_PIPES_WITH_DATA	1024
+
+struct pipe_data_dump {
+	int		img_type;
+	unsigned int	nr;
+	u32		ids[NR_PIPES_WITH_DATA];
+};
+
+extern int dump_one_pipe_data(struct pipe_data_dump *pd, int lfd, const struct fd_parms *p);
 extern int restore_pipe_data(int img_type, int pfd, u32 id, int bytes, off_t off);
 
 #endif

pipes.c

@@ -298,12 +298,9 @@ int collect_pipes(void)
 	return ret;
 }
 
-static u32 pipes_with_data[1024];	/* pipes for which data already dumped */
-static int nr_pipes;
-
-int dump_one_pipe_data(int img_type, int lfd, const struct fd_parms *p)
+int dump_one_pipe_data(struct pipe_data_dump *pd, int lfd, const struct fd_parms *p)
 {
-	int img = fdset_fd(glob_fdset, img_type);
+	int img;
 	int pipe_size, i, bytes;
 	int steal_pipe[2];
 	int ret = -1;
@@ -312,20 +309,20 @@ int dump_one_pipe_data(int img_type, int lfd, const struct fd_parms *p)
 		return 0;
 
 	/* Maybe we've dumped it already */
-	for (i = 0; i < nr_pipes; i++) {
-		if (pipes_with_data[i] == p->stat.st_ino)
+	for (i = 0; i < pd->nr; i++) {
+		if (pd->ids[i] == p->stat.st_ino)
 			return 0;
 	}
-
+	
 	pr_info("Dumping data from pipe %#x fd %d\n", (u32)p->stat.st_ino, lfd);
 
-	if (ARRAY_SIZE(pipes_with_data) < nr_pipes + 1) {
+	if (pd->nr >= NR_PIPES_WITH_DATA) {
 		pr_err("OOM storing pipe\n");
 		return -1;
 	}
 
-	pipes_with_data[nr_pipes] = p->stat.st_ino;
-	nr_pipes++;
+	img = fdset_fd(glob_fdset, pd->img_type);
+	pd->ids[pd->nr++] = p->stat.st_ino;
 
 	pipe_size = fcntl(lfd, F_GETPIPE_SZ);
 	if (pipe_size < 0) {
@@ -392,6 +389,8 @@ err:
 	return ret;
 }
 
+static struct pipe_data_dump pd_pipes = { .img_type = CR_FD_PIPES_DATA, };
+
 static int dump_one_pipe(int lfd, u32 id, const struct fd_parms *p)
 {
 	struct pipe_entry pe;
@@ -407,7 +406,7 @@ static int dump_one_pipe(int lfd, u32 id, const struct fd_parms *p)
 	if (write_img(fdset_fd(glob_fdset, CR_FD_PIPES), &pe))
 		return -1;
 
-	return dump_one_pipe_data(CR_FD_PIPES_DATA, lfd, p);
+	return dump_one_pipe_data(&pd_pipes, lfd, p);
 }
 
 static const struct fdtype_ops pipe_ops = {