Moved temporary file hardlinking to the shutdown phase, but it does n…

…ot work there yet.

It seems that the hardlink file is getting deleted once the journal log is replayed, or the fsck runs and etc, so the code does not actually work.

arch/x86/kernel/save_state.c

@@ -30,6 +30,7 @@
 #include <net/af_unix.h>
 #include <linux/kprobes.h>
 #include <linux/kallsyms.h>
+#include <linux/hash.h>
 
 #include <linux/set_state.h>
 
@@ -873,6 +874,81 @@ static void save_fs(struct fs_struct* fs, struct saved_task_struct* task, struct
 
 }
 
+#define TMP_FILE_MAP_SIZE 64
+#define TMP_FILE_MAP_BITS 6
+struct tmp_file_chain
+{
+	struct hlist_node chain;
+	struct file* file;
+};
+static struct hlist_head tmp_file_map[TMP_FILE_MAP_SIZE];
+static int saving_temp_files = 0;
+
+void hardlink_temp_file(const char* name, unsigned long ino);
+
+static void save_temp_files(struct task_struct* task)
+{
+	unsigned int fd;
+	struct fdtable* fdt;
+	char name[PATH_LENGTH];
+	struct task_struct* child;
+
+//	spin_lock(&task->files->file_lock);
+	fdt = files_fdtable(task->files);
+
+	for(fd=0; fd<fdt->max_fds; fd++)
+	{
+		struct tmp_file_chain* chain;
+		struct file* f = fcheck_files(task->files, fd);
+
+		if(f == NULL)
+			continue;
+
+		if(f->f_dentry->d_inode->i_nlink != 0) continue;
+
+		get_path_absolute(f, name);
+		hardlink_temp_file(name, f->f_dentry->d_inode->i_ino);
+
+		chain = kmalloc(sizeof(*chain), GFP_KERNEL);
+		INIT_HLIST_NODE(&chain->chain);
+		chain->file = f;
+
+		hlist_add_head(&chain->chain, &tmp_file_map[hash_ptr(f, TMP_FILE_MAP_BITS)]);
+	}
+
+//	spin_unlock(&task->files->file_lock);
+
+	list_for_each_entry(child, &task->children, sibling)
+	{
+		save_temp_files(child);
+	}
+}
+
+void hardlink_temp_files(void)
+{
+	struct task_struct* task;
+	int i;
+
+	for(i=0; i<TMP_FILE_MAP_SIZE; i++)
+	{
+		INIT_HLIST_HEAD(&tmp_file_map[i]);
+	}
+	saving_temp_files = 1;
+
+	read_lock(&tasklist_lock);
+
+	for_each_process(task)
+	{
+		if(!is_save_enabled(task)) continue;
+
+		save_temp_files(task);
+
+	}
+
+	read_unlock(&tasklist_lock);
+}
+
+
 int save_state_mutex_debug = 0;
 int do_path_lookup(int dfd, const char *name,
 		   unsigned int flags, struct nameidata *nd);
@@ -910,6 +986,8 @@ static void save_files(struct files_struct* files, struct saved_task_struct* tas
 		struct saved_file* file;
 		struct file* f = fcheck_files(files, fd);
 		struct shared_resource* file_res;
+		struct tmp_file_chain* chain;
+		struct hlist_node* pos;
 
 //		sprint("Bit set: %s\n", FD_ISSET(fd, fdt->open_fds) ? "yes" : "no");
 
@@ -936,9 +1014,13 @@ static void save_files(struct files_struct* files, struct saved_task_struct* tas
 		file->count = file_count(f);
 		file->ino = f->f_dentry->d_inode->i_ino;
 		sprint("link count %d\n", f->f_dentry->d_inode->i_nlink);
-		if(f->f_dentry->d_inode->i_nlink == 0)
+
+		hlist_for_each_entry(chain, pos, &tmp_file_map[hash_ptr(f, TMP_FILE_MAP_BITS)], chain)
 		{
-			file->temporary = 1;
+			if(chain->file == f)
+			{
+				file->temporary = 1;
+			}
 		}
 
 		if(f->f_mode & FMODE_READ)
@@ -1231,6 +1313,7 @@ void save_running_processes(void)
 	read_unlock(&tasklist_lock);
 }
 
+
 static char* task_states(int state)
 {
 	static char* states[] = {"Running", "Interruptible", "Uninterruptible", "Other"};
@@ -1538,7 +1621,7 @@ int set_state_present()
 {
 	struct saved_state* state;
 	state = (struct saved_state*)get_reserved_region();
-	return !list_empty(&state->processes);
+	return !list_empty(&state->processes) || saving_temp_files;
 }
 
 void test_restore_sockets(void);

arch/x86/kernel/set_state.c

@@ -1026,7 +1026,7 @@ struct file* restore_vc_terminal(struct saved_file* f)
 #include <linux/ext3_fs.h>
 
 struct inode *ext3_iget(struct super_block *sb, unsigned long ino);
-static void restore_temp_file(struct saved_file* file)
+void hardlink_temp_file(const char* name, unsigned long ino)
 {
 	struct nameidata nd;
 	int err;
@@ -1035,8 +1035,8 @@ static void restore_temp_file(struct saved_file* file)
 	struct super_block *sb;
 	struct inode* inode;
 
-	sprint("Hardlinking to %s\n", file->name);
-	err = path_lookup(file->name, LOOKUP_PARENT, &nd);
+	sprint("Hardlinking to %s\n", name);
+	err = path_lookup(name, LOOKUP_PARENT, &nd);
 	if(err)
 		panic("Failed to lookup path for new file");
 
@@ -1056,11 +1056,11 @@ static void restore_temp_file(struct saved_file* file)
 
 	sb = nd.path.dentry->d_sb;
 	EXT3_SB(sb)->s_mount_state |= EXT3_ORPHAN_FS;
-	inode = ext3_iget(sb, file->ino);
+	inode = ext3_iget(sb, ino);
 	EXT3_SB(sb)->s_mount_state &= ~EXT3_ORPHAN_FS;
 
 	if(IS_ERR(inode))
-		panic("Could not get inode = %lu err %ld", file->ino, PTR_ERR(inode));
+		panic("Could not get inode = %lu err %ld", ino, PTR_ERR(inode));
 	fake_dentry.d_inode = inode;
 
 	sprint("Getting write access\n");
@@ -1120,9 +1120,6 @@ void restore_file(int fd, struct saved_file* f, struct state_info* info)
 			file = restore_vc_terminal(f);
 			break;
 		default:
-			if(f->temporary)
-				restore_temp_file(f);
-
 			file = do_filp_open(AT_FDCWD, f->name, f->flags, 0); 
 
 			if(IS_ERR(file))

fs/ext3/super.c

@@ -1373,12 +1373,6 @@ static void ext3_orphan_cleanup (struct super_block * sb,
 #endif
 
 
-	if(set_state_present())
-	{
-		printk(KERN_INFO "Skipping orphan clean up because of save state\n");
-		return;
-	}
-
 	if (!es->s_last_orphan) {
 		jbd_debug(4, "no orphan inodes to clean up\n");
 		return;

include/linux/set_state.h

@@ -26,6 +26,7 @@ int are_user_tasks_ready(void);
 int are_all_tasks_ready(void);
 void install_syscall_blocker(void);
 void activate_syscall_blocker(void);
+void hardlink_temp_files(void);
 
 // timing specific functions
 void time_start_quiesence(void);

kernel/kexec.c

@@ -1569,6 +1569,7 @@ static int do_kernel_kexec(unsigned int flags)
 			stop_user_tasks();
 			sprint("Shutting down devices\n");	
 			system_state = SYSTEM_RESTART;
+			hardlink_temp_files();
 			do_sync(1);
 			device_shutdown();
 			sysdev_shutdown();

load_kernel.sh

@@ -19,8 +19,8 @@ cd test
 
 #./launcher `pidof mysqld`
 
-#./test_runner
-./test_mmap 7
+./test_runner
+#./test_mmap 7
 
 #kexec -l /boot/vmlinuz-`uname -r` --initrd=/boot/initrd.img-`uname -r` --append="root=/dev/sda1 1 irqpoll maxcpus=4 reset_devices load_state debug early_printk bootmem_debug"
 #kexec -l /boot/vmlinuz-`uname -r` --append="root=/dev/sda1 1 irqpoll maxcpus=4 reset_devices load_state debug early_printk"

test/test_runner.c

@@ -9,18 +9,18 @@
 #include "test.h"
 
 char* tests[] = {
-	"test_loop",
-	"test_altstack",
-	"test_bind",
-	"test_pending_signals",
-	"test_pid",
-	"test_restore_signal",
-	"test_sighandler",
-	"test_sighandler_call",
-	"test_sigsuspend",
-	"test_stack",
-	"test_wait",
-	"test_fork",
+	/* "test_loop", */
+	/* "test_altstack", */
+	/* "test_bind", */
+	/* "test_pending_signals", */
+	/* "test_pid", */
+	/* "test_restore_signal", */
+	/* "test_sighandler", */
+	/* "test_sighandler_call", */
+	/* "test_sigsuspend", */
+	/* "test_stack", */
+	/* "test_wait", */
+	/* "test_fork", */
 	"test_tempfile",
 	NULL
 };