Conversion from relay-on-procfs to relay-on-debugfs

9 files changed, 148 insertions, 165 deletions

diff --git a/ChangeLog b/ChangeLog
index fc0fa772..f624d905 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2006-09-19  Tom Zanussi  <zanussi@us.ibm.com>
+	
+	* README: Add CONFIG_DEBUG_FS to config options.
+	
 2006-09-18  Josh Stone  <joshua.i.stone@intel.com>
 
 	PR 3219
diff --git a/README b/README
index 2c47ee7a..6832b987 100644
--- a/README
+++ b/README
@@ -53,7 +53,8 @@ Tips:
 Building a kernel.org kernel:
 
 - Build the kernel using your normal procedures.  Enable
-  CONFIG_DEBUG_INFO, CONFIG_KPROBES, and optionally CONFIG_RELAY.
+  CONFIG_DEBUG_INFO, CONFIG_KPROBES, and optionally CONFIG_RELAY and
+  CONFIG_DEBUG_FS.
 - Boot into the kernel.
 - Make sure the large unstripped kernel image 'vmlinux' from your
   build can be found by systemtap (see above)  You can just symlink
diff --git a/runtime/stpd/ChangeLog b/runtime/stpd/ChangeLog
index dfc22682..d804d285 100644
--- a/runtime/stpd/ChangeLog
+++ b/runtime/stpd/ChangeLog
@@ -1,3 +1,14 @@
+2006-09-19  Tom Zanussi  <zanussi@us.ibm.com>
+	
+	* librelay.c (init_relayfs): Add debugfs path to relay files and
+	add new systemtap directory to path.
+	(init_stp): rmmod module on failure.
+	(merge_output): Remove debugging printfs left in code.
+	(close_relay_files): Clear relay_file descriptor after close.
+	(cleanup_and_exit): Allow cleanup and exit even if there was an
+	error opening relay files.
+	(stp_main_loop): Call cleanup_and_exit() if init_relayfs() fails.
+
 2006-09-18  Martin Hunt  <hunt@redhat.com>
 
 	* stpd.c (usage): Remove "-m" option.
diff --git a/runtime/stpd/librelay.c b/runtime/stpd/librelay.c
index 13b00ebf..fb600280 100644
--- a/runtime/stpd/librelay.c
+++ b/runtime/stpd/librelay.c
@@ -178,6 +178,7 @@ static void close_relayfs_files(int cpu)
 	
 	munmap(relay_buffer[cpu], total_bufsize);
 	close(relay_file[cpu]);
+	relay_file[cpu] = 0;
 	fclose(percpu_tmpfile[cpu]);
 }
 
@@ -387,6 +388,7 @@ static void read_last_buffers(void)
 }
 
 #define RELAYFS_MAGIC			0xF0B4A981
+#define DEBUGFS_MAGIC			0x64626720
 /**
  *	init_relayfs - create files and threads for relayfs processing
  *
@@ -417,17 +419,13 @@ int init_relayfs(void)
 		fprintf(stderr, "Could not execute %s\n", stp_check);
 		exit(1);
 	}
-	
+
 	if (statfs("/mnt/relay", &st) == 0 && (int) st.f_type == (int) RELAYFS_MAGIC)
-		sprintf(params.relay_filebase, "/mnt/relay/%d/cpu", getpid());
-	else {
-		char *ptr;
-		sprintf(params.relay_filebase, "/proc/systemtap/%s", modname);
-		ptr = index(params.relay_filebase,'.');
-		if (ptr)
-			*ptr = 0;
-		strcat(params.relay_filebase, "/cpu");
-	}
+ 		sprintf(params.relay_filebase, "/mnt/relay/systemtap/%d/cpu", getpid());
+ 	else if (statfs("/sys/kernel/debug", &st) == 0 && (int) st.f_type == (int) DEBUGFS_MAGIC)
+ 		sprintf(params.relay_filebase, "/sys/kernel/debug/systemtap/%d/cpu", getpid());
+ 	else
+ 		sprintf(params.relay_filebase, "/debug/systemtap/%d/cpu", getpid());
 	
 	for (i = 0; i < ncpus; i++) {
 		if (open_relayfs_files(i, params.relay_filebase) < 0) {
@@ -559,7 +557,7 @@ int init_stp(int print_summary)
 	control_channel = open(buf, O_RDWR);
 	if (control_channel < 0) {
 		fprintf(stderr, "ERROR: couldn't open control channel %s: errcode = %s\n", buf, strerror(errno));
-		return -1;
+		goto do_rmmod;
 	}
 
 	/* start target_cmd if necessary */
@@ -576,9 +574,15 @@ int init_stp(int print_summary)
 		if (target_cmd)
 			kill (target_pid, SIGKILL);
 		close(control_channel);
-		return -1;
+		goto do_rmmod;
 	}
 	return 0;
+
+do_rmmod:
+	snprintf(buf, sizeof(buf), "/sbin/rmmod -w %s", modname);
+	if (system(buf))
+		fprintf(stderr, "ERROR: couldn't rmmod probe module %s.\n", modname);
+	return -1;
 }
 
 
@@ -607,7 +611,6 @@ static int merge_output(void)
 		}
 		num[i] = 0;
 		buf[i] = malloc(MERGE_BUF_SIZE);
-		printf("buf[%d] = %p\n", i, buf[i]);
 		if (!buf[i]) {
 			fprintf(stderr,"Out of memory in merge_output(). Aborting merge.\n");
 			printf("Out of memory in merge_output(). Aborting merge.\n");
@@ -652,8 +655,6 @@ static int merge_output(void)
 
 		num[j] = 0;
 		if (fread_unlocked (&length[j], sizeof(uint32_t), 1, fp[j])) {
-			printf("length[%d] = %d\n", j, length[j]);
-			printf("buf[%d] = %p\n", j, buf[j]);
 			if (fread_unlocked (buf[j], length[j]+TIMESTAMP_SIZE, 1, fp[j]))
 				num[j] = *((uint32_t *)buf[j]);
 		}
@@ -689,7 +690,7 @@ static void cleanup_and_exit (int closed)
 		fprintf(stderr,"\nWaititing for processes to exit\n");
 	while(wait(NULL) > 0);
 
-	if (transport_mode == STP_TRANSPORT_RELAYFS) {
+	if (transport_mode == STP_TRANSPORT_RELAYFS && relay_file[0] > 0) {
 		kill_percpu_threads(ncpus);
 		while(1) {
 			pthread_mutex_lock(&processing_mutex);
@@ -707,7 +708,7 @@ static void cleanup_and_exit (int closed)
 	if (print_totals && verbose)
 		summarize();
 
-	if (transport_mode == STP_TRANSPORT_RELAYFS) {
+	if (transport_mode == STP_TRANSPORT_RELAYFS && relay_file[0] > 0) {
 		close_all_relayfs_files();
 		if (params.merge) {
 			merge_output();
@@ -817,10 +818,8 @@ int stp_main_loop(void)
 			if (!streaming()) {
 				rc = init_relayfs();
 				if (rc < 0) {
-					close(control_channel);
 					fprintf(stderr, "ERROR: couldn't init relayfs, exiting\n");
-					/* FIXME. Need to cleanup properly */
-					exit(1);
+					cleanup_and_exit(0);
 				}
 			} else if (outfile_name) {
 				ofp = fopen (outfile_name, "w");
diff --git a/runtime/transport/ChangeLog b/runtime/transport/ChangeLog
index 81618d7b..969f6fb0 100644
--- a/runtime/transport/ChangeLog
+++ b/runtime/transport/ChangeLog
@@ -1,3 +1,24 @@
+2006-09-19  Tom Zanussi  <zanussi@us.ibm.com>
+	
+	* procfs.c (_stp_get_proc_root): Removed.
+	(_stp_force_dir_creation): Removed.
+	(_stp_register_procfs): Remove unneeded procfs dentry code.  *
+	relayfs.c (_stp_create_buf_file): Remove code to create relay
+	files in procfs, add code to create in debugfs.
+	(_stp_remove_buf_file): Remove code to delete relay files in
+	procfs, add code to delete from debugfs.
+	(_stp_create_relay_dir): New.
+	(_stp_remove_relay_dir): New.
+	(_stp_get_relay_root): New.
+	(_stp_relayfs_close): Use new functions.
+	(_stp_relayfs_open): Consolidate alternative versions and remove
+	extraneous version.  * relayfs.h: Remove extraneous
+	_stp_relayfs_open prototype.
+	* transport.c (_stp_transport_open): Remove extraneous call to
+	_stp_relayfs_open() and remove call to _stp_unregister_procfs() on
+	failure - since it's called from cmd write, cmd can't be removed;
+	it's removed in normal shutdown anyway.
+
 2006-09-18  Martin Hunt  <hunt@redhat.com>
 
 	* transport_msgs.h (struct transport_info): Add merge field.
diff --git a/runtime/transport/procfs.c b/runtime/transport/procfs.c
index d61beba2..857a36c7 100644
--- a/runtime/transport/procfs.c
+++ b/runtime/transport/procfs.c
@@ -267,38 +267,6 @@ err:
 	return _stp_current_buffers;
 }
 
-#if defined (STP_RELAYFS) && defined(CONFIG_RELAY)
-struct dentry *module_dir_dentry;
-
-static inline struct dentry *_stp_get_proc_root(void)
-{
-	struct file_system_type *procfs_type;
-	struct super_block *procfs_sb;
-
-	procfs_type = get_fs_type("proc");
-	if (!procfs_type || list_empty(&procfs_type->fs_supers))
-		return NULL;
-	procfs_sb = list_entry(procfs_type->fs_supers.next,
-			       struct super_block, s_instances);
-	return procfs_sb->s_root;
-}
-
-static inline struct dentry *_stp_force_dir_creation(const char *dirname, struct dentry *parent)
-{
-	struct dentry *dir_dentry;
-
-	mutex_lock(&parent->d_inode->i_mutex);
-	dir_dentry = lookup_one_len(dirname, parent, strlen(dirname));
-	mutex_unlock(&parent->d_inode->i_mutex);
-	if (IS_ERR(dir_dentry)) {
-		dir_dentry = NULL;
-		remove_proc_entry(dirname, NULL);
-	}
-	
-	return dir_dentry;
-}
-#endif  /* STP_RELAYFS && CONFIG_RELAY */
-
 static int _stp_register_procfs (void)
 {
 	int i;
@@ -307,10 +275,6 @@ static int _stp_register_procfs (void)
 	int j;
 	char buf[8];
 #endif
-#if defined (CONFIG_RELAY)
-	struct dentry *proc_root_dentry;
-	struct dentry *systemtap_dir_dentry;
-#endif /* CONFIG_RELAY */
 	struct proc_dir_entry *de;
 	struct list_head *p, *tmp;
 
@@ -342,23 +306,11 @@ static int _stp_register_procfs (void)
 			goto err0;
 	}
 
-#if defined (STP_RELAYFS) && defined (CONFIG_RELAY)
-	proc_root_dentry = _stp_get_proc_root();
-	systemtap_dir_dentry = _stp_force_dir_creation(dirname, proc_root_dentry);
-	if (!systemtap_dir_dentry)
-		goto err0;
-#endif /* STP_RELAYFS && CONFIG_RELAY */
 	/* now create /proc/systemtap/module_name */
 	_stp_proc_mod = proc_mkdir (THIS_MODULE->name, _stp_proc_root);
 	if (_stp_proc_mod == NULL)
 		goto err0;
 
-#if defined (STP_RELAYFS) && defined (CONFIG_RELAY)
-	module_dir_dentry = _stp_force_dir_creation(THIS_MODULE->name, systemtap_dir_dentry);
-	if (!module_dir_dentry)
-		goto err0;
-#endif /* STP_RELAYFS && CONFIG_RELAY */
-
 #ifdef STP_RELAYFS	
 	/* now for each cpu "n", create /proc/systemtap/module_name/n  */
 	for_each_cpu(i) {
diff --git a/runtime/transport/relayfs.c b/runtime/transport/relayfs.c
index 3672c453..defe0087 100644
--- a/runtime/transport/relayfs.c
+++ b/runtime/transport/relayfs.c
@@ -78,35 +78,15 @@ static struct dentry *_stp_create_buf_file(const char *filename,
 					   struct rchan_buf *buf,
 					   int *is_global)
 {
-	struct proc_dir_entry *pde;
-	struct dentry *dentry;
-	struct proc_dir_entry *parent_pde = NULL;
-
-	if (parent)
-		parent_pde = PDE(parent->d_inode);
-	pde = create_proc_entry(filename, S_IFREG|S_IRUSR, parent_pde);
-	if (unlikely(!pde))
-		return NULL;    
-	pde->proc_fops = &relay_file_operations;
-
-	mutex_lock(&parent->d_inode->i_mutex);
-	dentry = lookup_one_len(filename, parent, strlen(filename));
-	mutex_unlock(&parent->d_inode->i_mutex);
-	if (IS_ERR(dentry))
-		remove_proc_entry(filename, parent_pde);
-
-	dentry->d_inode->u.generic_ip = buf;
-
-	return dentry;
+	return debugfs_create_file(filename, mode, parent, buf,
+                                   &relay_file_operations);
 }
 
 static int _stp_remove_buf_file(struct dentry *dentry)
 {
-	struct proc_dir_entry *pde = PDE(dentry->d_inode);
-	
-	remove_proc_entry(pde->name, pde->parent);
+        debugfs_remove(dentry);
 
-	return 0;
+        return 0;
 }
 #endif /* CONFIG_RELAY */
 
@@ -128,34 +108,85 @@ static struct rchan_callbacks stp_rchan_callbacks =
 };
 #endif  /* CONFIG_RELAY */
 
-/**
- *	_stp_relayfs_close - destroys relayfs channel
- *	@chan: the relayfs channel
- *	@dir: the directory containing the relayfs files
- */
+static struct dentry *_stp_create_relay_dir(const char *dirname, struct dentry *parent)
+{
+	struct dentry *dir;
+	
 #if defined (CONFIG_RELAY)
-void _stp_relayfs_close(struct rchan *chan, struct dentry *dir)
+	dir = debugfs_create_dir(dirname, parent);
+	if (IS_ERR(dir)) {
+		printk("STP: Couldn't create directory %s - debugfs not configured in.\n", dirname);
+		dir = NULL;
+	}
+#else
+	dir = relayfs_create_dir(dirname, parent);
+#endif
+
+	return dir;
+}
+
+static void _stp_remove_relay_dir(struct dentry *dir)
 {
-	if (!chan)
+	if (dir == NULL)
 		return;
-
-	relay_close(chan);
-	if (dir) {
-		struct proc_dir_entry *pde = PDE(dir->d_inode);
-		remove_proc_entry(pde->name, pde->parent);
-	}
+	
+#if defined (CONFIG_RELAY)
+		debugfs_remove(dir);
+#else
+		relayfs_remove_dir(dir);
+#endif
 }
+
+static struct dentry *_stp_get_relay_root(void)
+{
+	struct file_system_type *fs;
+	struct super_block *sb;
+	struct dentry *root;
+	char *dirname = "systemtap";
+
+	root = _stp_create_relay_dir(dirname, NULL);
+	if (root)
+		return root;
+	
+#if defined (CONFIG_RELAY)
+	fs = get_fs_type("debugfs");
 #else
+	fs = get_fs_type("relayfs");
+#endif
+	if (!fs)
+		return NULL;
+
+	sb = list_entry(fs->fs_supers.next, struct super_block, s_instances);
+	mutex_lock(&sb->s_root->d_inode->i_mutex);
+	root = lookup_one_len(dirname, sb->s_root, strlen(dirname));
+	mutex_unlock(&sb->s_root->d_inode->i_mutex);
+	if (!IS_ERR(root))
+		dput(root);
+	
+	return root;
+}
+
+static void _stp_put_relay_root(struct dentry *root)
+{
+	if (root)
+		_stp_remove_relay_dir(root);
+}
+
+static struct dentry *_relay_root;
+
+/**
+ *	_stp_relayfs_close - destroys relayfs channel
+ *	@chan: the relayfs channel
+ *	@dir: the directory containing the relayfs files
+ */
 void _stp_relayfs_close(struct rchan *chan, struct dentry *dir)
 {
 	if (!chan)
 		return;
-
 	relay_close(chan);
-	if (dir)
-		relayfs_remove_dir(dir);
+	_stp_remove_relay_dir(dir);
+	_stp_put_relay_root(_relay_root);
 }
-#endif /* CONFIG_RELAY */
 
 /**
  *	_stp_relayfs_open - create relayfs channel
@@ -163,56 +194,35 @@ void _stp_relayfs_close(struct rchan *chan, struct dentry *dir)
  *	@subbuf_size: size of relayfs sub-buffers
  *	@pid: daemon pid
  *	@outdir: receives directory dentry
- *	@parentdir: parent directory dentry
  *
  *	Returns relay channel, NULL on failure
  *
  *	Creates relayfs files as /systemtap/pid/cpuX in relayfs root
  */
-#if defined (CONFIG_RELAY)
-extern struct dentry *module_dentry;
 struct rchan *_stp_relayfs_open(unsigned n_subbufs,
 				unsigned subbuf_size,
 				int pid,
-				struct dentry **outdir,
-				struct dentry *parent_dir)
+				struct dentry **outdir)
 {
 	char dirname[16];
 	struct rchan *chan;
-	struct dentry* dir = NULL;
+	struct dentry* root, *dir;
 
 	sprintf(dirname, "%d", pid);
 	
-	/* TODO: need to create systemtap dir */
-	chan = relay_open("cpu", parent_dir, subbuf_size,
-			  n_subbufs, &stp_rchan_callbacks);
-	if (!chan) {
-		printk("STP: couldn't create relayfs channel.\n");
-		if (dir)
-			remove_proc_entry(dirname, NULL);
+	root = _stp_get_relay_root();
+	if (!root) {
+		printk("STP: couldn't get relay root dir.\n");
+		return NULL;
 	}
-	*outdir = dir;
-	return chan;
-}
-#else
-struct rchan *_stp_relayfs_open(unsigned n_subbufs,
-				unsigned subbuf_size,
-				int pid,
-				struct dentry **outdir)
-{
-	char dirname[16];
-	struct rchan *chan;
-	struct dentry* dir = NULL;
 
-	sprintf(dirname, "%d", pid);
-	
-	/* TODO: need to create systemtap dir */
-	dir = relayfs_create_dir(dirname, NULL);
+	dir = _stp_create_relay_dir(dirname, root);
 	if (!dir) {
-		printk("STP: couldn't create relayfs dir %s.\n", dirname);
+		printk("STP: couldn't create relay dir %s.\n", dirname);
+		_stp_put_relay_root(root);
 		return NULL;
 	}
-
+	
 #if (RELAYFS_CHANNEL_VERSION >= 4)
 	chan = relay_open("cpu", dir, subbuf_size,
 			  n_subbufs, &stp_rchan_callbacks);
@@ -222,15 +232,15 @@ struct rchan *_stp_relayfs_open(unsigned n_subbufs,
 #endif /* RELAYFS_CHANNEL_VERSION >= 4 */
 
 	if (!chan) {
-		printk("STP: couldn't create relayfs channel.\n");
-		if (dir)
-			relayfs_remove_dir(dir);
+		printk("STP: couldn't create relay channel.\n");
+		_stp_remove_relay_dir(dir);
+		_stp_put_relay_root(root);
 	}
 
+	_relay_root = root;
 	*outdir = dir;
 	return chan;
 }
-#endif /* CONFIG_RELAY */
 
 #endif /* _TRANSPORT_RELAYFS_C_ */
 
diff --git a/runtime/transport/relayfs.h b/runtime/transport/relayfs.h
index c871db31..c47f4b98 100644
--- a/runtime/transport/relayfs.h
+++ b/runtime/transport/relayfs.h
@@ -9,23 +9,17 @@
 #  include <linux/relayfs_fs.h>
 #elif defined (CONFIG_RELAY)
 #  include <linux/relay.h>
-#  include <linux/namei.h>
+#  include <linux/debugfs.h>
 #else
 #  undef STP_RELAYFS
 #endif
 
-#if defined (CONFIG_RELAY)
-struct rchan *_stp_relayfs_open(unsigned n_subbufs,
-				unsigned subbuf_size,
-				int pid,
-				struct dentry **outdir,
-				struct dentry *parent_dir);
-#else
+#  include <linux/namei.h>
+
 struct rchan *_stp_relayfs_open(unsigned n_subbufs,
 				unsigned subbuf_size,
 				int pid,
 				struct dentry **outdir);
-#endif
 
 void _stp_relayfs_close(struct rchan *chan, struct dentry *dir);
 
diff --git a/runtime/transport/transport.c b/runtime/transport/transport.c
index c9be3311..8cc624a9 100644
--- a/runtime/transport/transport.c
+++ b/runtime/transport/transport.c
@@ -204,10 +204,6 @@ void _stp_transport_close()
 	kbug("---- CLOSED ----\n");
 }
 
-#if defined (STP_RELAYFS) && defined (CONFIG_RELAY)
-extern struct dentry *module_dir_dentry;
-#endif /* STP_RELAYFS && CONFIG_RELAY */
-
 /**
  *	_stp_transport_open - open proc and relayfs channels
  *      with proper parameters
@@ -247,15 +243,10 @@ int _stp_transport_open(struct transport_info *info)
 		info->merge = 1;
 #endif
 
-#if defined (CONFIG_RELAY)
-		_stp_chan = _stp_relayfs_open(n_subbufs, subbuf_size, _stp_pid, &_stp_dir, module_dir_dentry);
-#else
 		_stp_chan = _stp_relayfs_open(n_subbufs, subbuf_size, _stp_pid, &_stp_dir);
-#endif /* CONFIG_RELAY */
-		if (!_stp_chan) {
-			_stp_unregister_procfs();
+
+		if (!_stp_chan)
 			return -ENOMEM;
-		}
 		kbug ("stp_transport_open: %u Mb buffers, subbuf_size=%u, n_subbufs=%u\n",
 		      info->buf_size, subbuf_size, n_subbufs);
 	} else