@@ -2,8 +2,9 @@
/*
* event_inode.c - part of tracefs, a pseudo file system for activating tracing
*
- * Copyright (C) 2020-23 VMware Inc, author: Steven Rostedt (VMware) <rostedt@goodmis.org>
+ * Copyright (C) 2020-23 VMware Inc, author: Steven Rostedt <rostedt@goodmis.org>
* Copyright (C) 2020-23 VMware Inc, author: Ajay Kaher <akaher@vmware.com>
+ * Copyright (C) 2023 Google, author: Steven Rostedt <rostedt@goodmis.org>
*
* eventfs is used to dynamically create inodes and dentries based on the
* meta data provided by the tracing system.
@@ -23,46 +24,6 @@
#include <linux/delay.h>
#include "internal.h"
-struct eventfs_inode {
- struct list_head e_top_files;
-};
-
-/*
- * struct eventfs_file - hold the properties of the eventfs files and
- * directories.
- * @name: the name of the file or directory to create
- * @d_parent: holds parent's dentry
- * @dentry: once accessed holds dentry
- * @list: file or directory to be added to parent directory
- * @ei: list of files and directories within directory
- * @fop: file_operations for file or directory
- * @iop: inode_operations for file or directory
- * @data: something that the caller will want to get to later on
- * @mode: the permission that the file or directory should have
- */
-struct eventfs_file {
- const char *name;
- struct dentry *d_parent;
- struct dentry *dentry;
- struct list_head list;
- struct eventfs_inode *ei;
- const struct file_operations *fop;
- const struct inode_operations *iop;
- /*
- * Union - used for deletion
- * @del_list: list of eventfs_file to delete
- * @rcu: eventfs_file to delete in RCU
- * @is_freed: node is freed if one of the above is set
- */
- union {
- struct list_head del_list;
- struct rcu_head rcu;
- unsigned long is_freed;
- };
- void *data;
- umode_t mode;
-};
-
static DEFINE_MUTEX(eventfs_mutex);
DEFINE_STATIC_SRCU(eventfs_srcu);
@@ -93,16 +54,9 @@ static const struct file_operations eventfs_file_operations = {
* @data: something that the caller will want to get to later on.
* @fop: struct file_operations that should be used for this file.
*
- * This is the basic "create a file" function for tracefs. It allows for a
- * wide range of flexibility in creating a file.
- *
- * This function will return a pointer to a dentry if it succeeds. This
- * pointer must be passed to the tracefs_remove() function when the file is
- * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, %NULL will be returned.
- *
- * If tracefs is not enabled in the kernel, the value -%ENODEV will be
- * returned.
+ * This function creates a dentry that represents a file in the eventsfs_inode
+ * directory. The inode.i_private pointer will point to @data in the open()
+ * call.
*/
static struct dentry *create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
@@ -118,6 +72,7 @@ static struct dentry *create_file(const char *name, umode_t mode,
if (WARN_ON_ONCE(!S_ISREG(mode)))
return NULL;
+ WARN_ON_ONCE(!parent);
dentry = eventfs_start_creating(name, parent);
if (IS_ERR(dentry))
@@ -142,20 +97,11 @@ static struct dentry *create_file(const char *name, umode_t mode,
* create_dir - create a dir in the tracefs filesystem
* @name: the name of the file to create.
* @parent: parent dentry for this file.
- * @data: something that the caller will want to get to later on.
- *
- * This is the basic "create a dir" function for eventfs. It allows for a
- * wide range of flexibility in creating a dir.
- *
- * This function will return a pointer to a dentry if it succeeds. This
- * pointer must be passed to the tracefs_remove() function when the file is
- * to be removed (no automatic cleanup happens if your module is unloaded,
- * you are responsible here.) If an error occurs, %NULL will be returned.
*
- * If tracefs is not enabled in the kernel, the value -%ENODEV will be
- * returned.
+ * This function will create a dentry for a directory represented by
+ * a eventfs_inode.
*/
-static struct dentry *create_dir(const char *name, struct dentry *parent, void *data)
+static struct dentry *create_dir(const char *name, struct dentry *parent)
{
struct tracefs_inode *ti;
struct dentry *dentry;
@@ -172,7 +118,6 @@ static struct dentry *create_dir(const char *name, struct dentry *parent, void *
inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
inode->i_op = &eventfs_root_dir_inode_operations;
inode->i_fop = &eventfs_file_operations;
- inode->i_private = data;
ti = get_tracefs(inode);
ti->flags |= TRACEFS_EVENT_INODE;
@@ -185,18 +130,18 @@ static struct dentry *create_dir(const char *name, struct dentry *parent, void *
}
/**
- * eventfs_set_ef_status_free - set the ef->status to free
+ * eventfs_set_ei_status_free - remove the dentry reference from an eventfs_inode
* @ti: the tracefs_inode of the dentry
- * @dentry: dentry who's status to be freed
+ * @dentry: dentry which has the reference to remove.
*
- * eventfs_set_ef_status_free will be called if no more
- * references remain
+ * Remove the association between a dentry from an eventfs_inode.
*/
-void eventfs_set_ef_status_free(struct tracefs_inode *ti, struct dentry *dentry)
+void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry)
{
struct tracefs_inode *ti_parent;
+ struct eventfs_inode *ei_child, *tmp;
struct eventfs_inode *ei;
- struct eventfs_file *ef, *tmp;
+ int i;
/* The top level events directory may be freed by this */
if (unlikely(ti->flags & TRACEFS_EVENT_TOP_INODE)) {
@@ -207,9 +152,9 @@ void eventfs_set_ef_status_free(struct tracefs_inode *ti, struct dentry *dentry)
ei = ti->private;
/* Record all the top level files */
- list_for_each_entry_srcu(ef, &ei->e_top_files, list,
+ list_for_each_entry_srcu(ei_child, &ei->children, list,
lockdep_is_held(&eventfs_mutex)) {
- list_add_tail(&ef->del_list, &ef_del_list);
+ list_add_tail(&ei_child->del_list, &ef_del_list);
}
/* Nothing should access this, but just in case! */
@@ -218,11 +163,13 @@ void eventfs_set_ef_status_free(struct tracefs_inode *ti, struct dentry *dentry)
mutex_unlock(&eventfs_mutex);
/* Now safely free the top level files and their children */
- list_for_each_entry_safe(ef, tmp, &ef_del_list, del_list) {
- list_del(&ef->del_list);
- eventfs_remove(ef);
+ list_for_each_entry_safe(ei_child, tmp, &ef_del_list, del_list) {
+ list_del(&ei_child->del_list);
+ eventfs_remove_dir(ei_child);
}
+ kfree_const(ei->name);
+ kfree(ei->d_children);
kfree(ei);
return;
}
@@ -233,68 +180,162 @@ void eventfs_set_ef_status_free(struct tracefs_inode *ti, struct dentry *dentry)
if (!ti_parent || !(ti_parent->flags & TRACEFS_EVENT_INODE))
goto out;
- ef = dentry->d_fsdata;
- if (!ef)
+ ei = dentry->d_fsdata;
+ if (!ei)
goto out;
/*
- * If ef was freed, then the LSB bit is set for d_fsdata.
+ * If ei was freed, then the LSB bit is set for d_fsdata.
* But this should not happen, as it should still have a
* ref count that prevents it. Warn in case it does.
*/
- if (WARN_ON_ONCE((unsigned long)ef & 1))
+ if (WARN_ON_ONCE((unsigned long)ei & 1))
goto out;
+ /* This could belong to one of the files of the ei */
+ if (ei->dentry != dentry) {
+ for (i = 0; i < ei->nr_entries; i++) {
+ if (ei->d_children[i] == dentry)
+ break;
+ }
+ if (WARN_ON_ONCE(i == ei->nr_entries))
+ goto out;
+ ei->d_children[i] = NULL;
+ } else {
+ ei->dentry = NULL;
+ }
+
dentry->d_fsdata = NULL;
- ef->dentry = NULL;
-out:
+ out:
mutex_unlock(&eventfs_mutex);
}
+/**
+ * create_file_dentry - create a dentry for a file of an eventfs_inode
+ * @ei: the eventfs_inode that the file will be created under
+ * @e_dentry: a pointer to the d_children[] of the @ei
+ * @parent: The parent dentry of the created file.
+ * @name: The name of the file to create
+ * @mode: The mode of the file.
+ * @data: The data to use to set the inode of the file with on open()
+ * @fops: The fops of the file to be created.
+ * @lookup: If called by the lookup routine, in which case, dput() the created dentry.
+ *
+ * Create a dentry for a file of an eventfs_inode @ei and place it into the
+ * address located at @e_dentry. If the @e_dentry already has a dentry, then
+ * just do a dget() on it and return. Otherwise create the dentry and attach it.
+ */
+static struct dentry *
+create_file_dentry(struct eventfs_inode *ei, struct dentry **e_dentry,
+ struct dentry *parent, const char *name, umode_t mode, void *data,
+ const struct file_operations *fops, bool lookup)
+{
+ struct dentry *dentry;
+ bool invalidate = false;
+
+ mutex_lock(&eventfs_mutex);
+ /* If the e_dentry already has a dentry, use it */
+ if (*e_dentry) {
+ /* lookup does not need to up the ref count */
+ if (!lookup)
+ dget(*e_dentry);
+ mutex_unlock(&eventfs_mutex);
+ return *e_dentry;
+ }
+ mutex_unlock(&eventfs_mutex);
+
+ /* The lookup already has the parent->d_inode locked */
+ if (!lookup)
+ inode_lock(parent->d_inode);
+
+ dentry = create_file(name, mode, parent, data, fops);
+
+ if (!lookup)
+ inode_unlock(parent->d_inode);
+
+ mutex_lock(&eventfs_mutex);
+
+ if (IS_ERR_OR_NULL(dentry)) {
+ /*
+ * When the mutex was released, something else could have
+ * created the dentry for this e_dentry. In which case
+ * use that one.
+ *
+ * Note, with the mutex held, the e_dentry cannot have content
+ * and the ei->is_freed be true at the same time.
+ */
+ WARN_ON_ONCE(ei->is_freed);
+ dentry = *e_dentry;
+ /* The lookup does not need to up the dentry refcount */
+ if (dentry && !lookup)
+ dget(dentry);
+ mutex_unlock(&eventfs_mutex);
+ return dentry;
+ }
+
+ if (!*e_dentry && !ei->is_freed) {
+ *e_dentry = dentry;
+ dentry->d_fsdata = ei;
+ } else {
+ /*
+ * Should never happen unless we get here due to being freed.
+ * Otherwise it means two dentries exist with the same name.
+ */
+ WARN_ON_ONCE(!ei->is_freed);
+ invalidate = true;
+ }
+ mutex_unlock(&eventfs_mutex);
+
+ if (invalidate)
+ d_invalidate(dentry);
+
+ if (lookup || invalidate)
+ dput(dentry);
+
+ return invalidate ? NULL : dentry;
+}
+
/**
* eventfs_post_create_dir - post create dir routine
- * @ef: eventfs_file of recently created dir
+ * @ei: eventfs_inode of recently created dir
*
* Map the meta-data of files within an eventfs dir to their parent dentry
*/
-static void eventfs_post_create_dir(struct eventfs_file *ef)
+static void eventfs_post_create_dir(struct eventfs_inode *ei)
{
- struct eventfs_file *ef_child;
+ struct eventfs_inode *ei_child;
struct tracefs_inode *ti;
/* srcu lock already held */
/* fill parent-child relation */
- list_for_each_entry_srcu(ef_child, &ef->ei->e_top_files, list,
+ list_for_each_entry_srcu(ei_child, &ei->children, list,
srcu_read_lock_held(&eventfs_srcu)) {
- ef_child->d_parent = ef->dentry;
+ ei_child->d_parent = ei->dentry;
}
- ti = get_tracefs(ef->dentry->d_inode);
- ti->private = ef->ei;
+ ti = get_tracefs(ei->dentry->d_inode);
+ ti->private = ei;
}
/**
- * create_dentry - helper function to create dentry
- * @ef: eventfs_file of file or directory to create
- * @parent: parent dentry
- * @lookup: true if called from lookup routine
+ * create_dir_dentry - Create a directory dentry for the eventfs_inode
+ * @ei: The eventfs_inode to create the directory for
+ * @parent: The dentry of the parent of this directory
+ * @lookup: True if this is called by the lookup code
*
- * Used to create a dentry for file/dir, executes post dentry creation routine
+ * This creates and attaches a directory dentry to the eventfs_inode @ei.
*/
static struct dentry *
-create_dentry(struct eventfs_file *ef, struct dentry *parent, bool lookup)
+create_dir_dentry(struct eventfs_inode *ei, struct dentry *parent, bool lookup)
{
bool invalidate = false;
- struct dentry *dentry;
+ struct dentry *dentry = NULL;
mutex_lock(&eventfs_mutex);
- if (ef->is_freed) {
- mutex_unlock(&eventfs_mutex);
- return NULL;
- }
- if (ef->dentry) {
- dentry = ef->dentry;
- /* On dir open, up the ref count */
+ if (ei->dentry) {
+ /* If the dentry already has a dentry, use it */
+ dentry = ei->dentry;
+ /* lookup does not need to up the ref count */
if (!lookup)
dget(dentry);
mutex_unlock(&eventfs_mutex);
@@ -302,42 +343,44 @@ create_dentry(struct eventfs_file *ef, struct dentry *parent, bool lookup)
}
mutex_unlock(&eventfs_mutex);
+ /* The lookup already has the parent->d_inode locked */
if (!lookup)
inode_lock(parent->d_inode);
- if (ef->ei)
- dentry = create_dir(ef->name, parent, ef->data);
- else
- dentry = create_file(ef->name, ef->mode, parent,
- ef->data, ef->fop);
+ dentry = create_dir(ei->name, parent);
if (!lookup)
inode_unlock(parent->d_inode);
mutex_lock(&eventfs_mutex);
- if (IS_ERR_OR_NULL(dentry)) {
- /* If the ef was already updated get it */
- dentry = ef->dentry;
+
+ if (IS_ERR_OR_NULL(dentry) && !ei->is_freed) {
+ /*
+ * When the mutex was released, something else could have
+ * created the dentry for this e_dentry. In which case
+ * use that one.
+ *
+ * Note, with the mutex held, the e_dentry cannot have content
+ * and the ei->is_freed be true at the same time.
+ */
+ dentry = ei->dentry;
if (dentry && !lookup)
dget(dentry);
mutex_unlock(&eventfs_mutex);
return dentry;
}
- if (!ef->dentry && !ef->is_freed) {
- ef->dentry = dentry;
- if (ef->ei)
- eventfs_post_create_dir(ef);
- dentry->d_fsdata = ef;
+ if (!ei->dentry && !ei->is_freed) {
+ ei->dentry = dentry;
+ eventfs_post_create_dir(ei);
+ dentry->d_fsdata = ei;
} else {
- /* A race here, should try again (unless freed) */
- invalidate = true;
-
/*
* Should never happen unless we get here due to being freed.
* Otherwise it means two dentries exist with the same name.
*/
- WARN_ON_ONCE(!ef->is_freed);
+ WARN_ON_ONCE(!ei->is_freed);
+ invalidate = true;
}
mutex_unlock(&eventfs_mutex);
if (invalidate)
@@ -349,50 +392,85 @@ create_dentry(struct eventfs_file *ef, struct dentry *parent, bool lookup)
return invalidate ? NULL : dentry;
}
-static bool match_event_file(struct eventfs_file *ef, const char *name)
-{
- bool ret;
-
- mutex_lock(&eventfs_mutex);
- ret = !ef->is_freed && strcmp(ef->name, name) == 0;
- mutex_unlock(&eventfs_mutex);
-
- return ret;
-}
-
/**
* eventfs_root_lookup - lookup routine to create file/dir
* @dir: in which a lookup is being done
* @dentry: file/dir dentry
- * @flags: to pass as flags parameter to simple lookup
+ * @flags: Just passed to simple_lookup()
*
- * Used to create a dynamic file/dir within @dir. Use the eventfs_inode
- * list of meta data to find the information needed to create the file/dir.
+ * Used to create dynamic file/dir with-in @dir, search with-in @ei
+ * list, if @dentry found go ahead and create the file/dir
*/
+
static struct dentry *eventfs_root_lookup(struct inode *dir,
struct dentry *dentry,
unsigned int flags)
{
+ const struct file_operations *fops;
+ const struct eventfs_entry *entry;
+ struct eventfs_inode *ei_child;
struct tracefs_inode *ti;
struct eventfs_inode *ei;
- struct eventfs_file *ef;
+ struct dentry *ei_dentry = NULL;
struct dentry *ret = NULL;
+ const char *name = dentry->d_name.name;
+ bool created = false;
+ umode_t mode;
+ void *data;
int idx;
+ int i;
+ int r;
ti = get_tracefs(dir);
if (!(ti->flags & TRACEFS_EVENT_INODE))
return NULL;
- ei = ti->private;
+ /* Grab srcu to prevent the ei from going away */
idx = srcu_read_lock(&eventfs_srcu);
- list_for_each_entry_srcu(ef, &ei->e_top_files, list,
+
+ /*
+ * Grab the eventfs_mutex to consistent value from ti->private.
+ * This s
+ */
+ mutex_lock(&eventfs_mutex);
+ ei = READ_ONCE(ti->private);
+ if (ei)
+ ei_dentry = READ_ONCE(ei->dentry);
+ mutex_unlock(&eventfs_mutex);
+
+ if (!ei || !ei_dentry)
+ goto out;
+
+ data = ei->data;
+
+ list_for_each_entry_srcu(ei_child, &ei->children, list,
srcu_read_lock_held(&eventfs_srcu)) {
- if (!match_event_file(ef, dentry->d_name.name))
+ if (strcmp(ei_child->name, name) != 0)
continue;
ret = simple_lookup(dir, dentry, flags);
- create_dentry(ef, ef->d_parent, true);
+ create_dir_dentry(ei_child, ei_dentry, true);
+ created = true;
break;
}
+
+ if (created)
+ goto out;
+
+ for (i = 0; i < ei->nr_entries; i++) {
+ entry = &ei->entries[i];
+ if (strcmp(name, entry->name) == 0) {
+ void *cdata = data;
+ r = entry->callback(name, &mode, &cdata, &fops);
+ if (r <= 0)
+ continue;
+ ret = simple_lookup(dir, dentry, flags);
+ create_file_dentry(ei, &ei->d_children[i],
+ ei_dentry, name, mode, cdata,
+ fops, true);
+ break;
+ }
+ }
+ out:
srcu_read_unlock(&eventfs_srcu, idx);
return ret;
}
@@ -432,29 +510,48 @@ static int eventfs_release(struct inode *inode, struct file *file)
return dcache_dir_close(inode, file);
}
+static int add_dentries(struct dentry ***dentries, struct dentry *d, int cnt)
+{
+ struct dentry **tmp;
+
+ tmp = krealloc(*dentries, sizeof(d) * (cnt + 2), GFP_KERNEL);
+ if (!tmp)
+ return -1;
+ tmp[cnt] = d;
+ tmp[cnt + 1] = NULL;
+ *dentries = tmp;
+ return 0;
+}
+
/**
* dcache_dir_open_wrapper - eventfs open wrapper
* @inode: not used
- * @file: dir to be opened (to create its child)
+ * @file: dir to be opened (to create it's children)
*
- * Used to dynamically create the file/dir within @file. @file is really a
- * directory and all the files/dirs of the children within @file will be
- * created. If any of the files/dirs have already been created, their
- * reference count will be incremented.
+ * Used to dynamic create file/dir with-in @file, all the
+ * file/dir will be created. If already created then references
+ * will be increased
*/
static int dcache_dir_open_wrapper(struct inode *inode, struct file *file)
{
+ const struct file_operations *fops;
+ const struct eventfs_entry *entry;
+ struct eventfs_inode *ei_child;
struct tracefs_inode *ti;
struct eventfs_inode *ei;
- struct eventfs_file *ef;
struct dentry_list *dlist;
struct dentry **dentries = NULL;
- struct dentry *dentry = file_dentry(file);
+ struct dentry *parent = file_dentry(file);
struct dentry *d;
struct inode *f_inode = file_inode(file);
+ const char *name = parent->d_name.name;
+ umode_t mode;
+ void *data;
int cnt = 0;
int idx;
int ret;
+ int i;
+ int r;
ti = get_tracefs(f_inode);
if (!(ti->flags & TRACEFS_EVENT_INODE))
@@ -463,25 +560,51 @@ static int dcache_dir_open_wrapper(struct inode *inode, struct file *file)
if (WARN_ON_ONCE(file->private_data))
return -EINVAL;
+ idx = srcu_read_lock(&eventfs_srcu);
+
+ mutex_lock(&eventfs_mutex);
+ ei = READ_ONCE(ti->private);
+ mutex_unlock(&eventfs_mutex);
+
+ if (!ei) {
+ srcu_read_unlock(&eventfs_srcu, idx);
+ return -EINVAL;
+ }
+
+
+ data = ei->data;
+
dlist = kmalloc(sizeof(*dlist), GFP_KERNEL);
- if (!dlist)
+ if (!dlist) {
+ srcu_read_unlock(&eventfs_srcu, idx);
return -ENOMEM;
+ }
- ei = ti->private;
- idx = srcu_read_lock(&eventfs_srcu);
- list_for_each_entry_srcu(ef, &ei->e_top_files, list,
+ list_for_each_entry_srcu(ei_child, &ei->children, list,
srcu_read_lock_held(&eventfs_srcu)) {
- d = create_dentry(ef, dentry, false);
+ d = create_dir_dentry(ei_child, parent, false);
if (d) {
- struct dentry **tmp;
+ ret = add_dentries(&dentries, d, cnt);
+ if (ret < 0)
+ break;
+ cnt++;
+ }
+ }
- tmp = krealloc(dentries, sizeof(d) * (cnt + 2), GFP_KERNEL);
- if (!tmp)
+ for (i = 0; i < ei->nr_entries; i++) {
+ void *cdata = data;
+ entry = &ei->entries[i];
+ name = entry->name;
+ r = entry->callback(name, &mode, &cdata, &fops);
+ if (r <= 0)
+ continue;
+ d = create_file_dentry(ei, &ei->d_children[i],
+ parent, name, mode, cdata, fops, false);
+ if (d) {
+ ret = add_dentries(&dentries, d, cnt);
+ if (ret < 0)
break;
- tmp[cnt] = d;
- tmp[cnt + 1] = NULL;
cnt++;
- dentries = tmp;
}
}
srcu_read_unlock(&eventfs_srcu, idx);
@@ -514,63 +637,90 @@ static int dcache_readdir_wrapper(struct file *file, struct dir_context *ctx)
}
/**
- * eventfs_prepare_ef - helper function to prepare eventfs_file
- * @name: the name of the file/directory to create.
- * @mode: the permission that the file should have.
- * @fop: struct file_operations that should be used for this file/directory.
- * @iop: struct inode_operations that should be used for this file/directory.
- * @data: something that the caller will want to get to later on. The
- * inode.i_private pointer will point to this value on the open() call.
+ * eventfs_create_dir - Create the eventfs_inode for this directory
+ * @name: The name of the directory to create.
+ * @parent: The eventfs_inode of the parent directory.
+ * @entries: A list of entries that represent the files under this directory
+ * @size: The number of @entries
+ * @data: The default data to pass to the files (an entry may override it).
+ *
+ * This function creates the descriptor to represent a directory in the
+ * eventfs. This descriptor is an eventfs_inode, and it is returned to be
+ * used to create other children underneath.
+ *
+ * The @entries is an array of eventfs_entry structures which has:
+ * const char *name
+ * eventfs_callback callback;
+ *
+ * The name is the name of the file, and the callback is a pointer to a function
+ * that will be called when the file is reference (either by lookup or by
+ * reading a directory). The callback is of the prototype:
*
- * This function allocates and fills the eventfs_file structure.
+ * int callback(const char *name, umode_t *mode, void **data,
+ * const struct file_operations **fops);
+ *
+ * When a file needs to be created, this callback will be called with
+ * name = the name of the file being created (so that the same callback
+ * may be used for multiple files).
+ * mode = a place to set the file's mode
+ * data = A pointer to @data, and the callback may replace it, which will
+ * cause the file created to pass the new data to the open() call.
+ * fops = the fops to use for the created file.
*/
-static struct eventfs_file *eventfs_prepare_ef(const char *name, umode_t mode,
- const struct file_operations *fop,
- const struct inode_operations *iop,
- void *data)
+struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode *parent,
+ const struct eventfs_entry *entries,
+ int size, void *data)
{
- struct eventfs_file *ef;
+ struct eventfs_inode *ei;
- ef = kzalloc(sizeof(*ef), GFP_KERNEL);
- if (!ef)
+ if (!parent)
+ return ERR_PTR(-EINVAL);
+
+ ei = kzalloc(sizeof(*ei), GFP_KERNEL);
+ if (!ei)
return ERR_PTR(-ENOMEM);
- ef->name = kstrdup(name, GFP_KERNEL);
- if (!ef->name) {
- kfree(ef);
+ ei->name = kstrdup_const(name, GFP_KERNEL);
+ if (!ei->name) {
+ kfree(ei);
return ERR_PTR(-ENOMEM);
}
- if (S_ISDIR(mode)) {
- ef->ei = kzalloc(sizeof(*ef->ei), GFP_KERNEL);
- if (!ef->ei) {
- kfree(ef->name);
- kfree(ef);
+ if (size) {
+ ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL);
+ if (!ei->d_children) {
+ kfree_const(ei->name);
+ kfree(ei);
return ERR_PTR(-ENOMEM);
}
- INIT_LIST_HEAD(&ef->ei->e_top_files);
- } else {
- ef->ei = NULL;
}
- ef->iop = iop;
- ef->fop = fop;
- ef->mode = mode;
- ef->data = data;
- return ef;
+ ei->entries = entries;
+ ei->nr_entries = size;
+ ei->data = data;
+ INIT_LIST_HEAD(&ei->children);
+
+ mutex_lock(&eventfs_mutex);
+ list_add_tail(&ei->list, &parent->children);
+ ei->d_parent = parent->dentry;
+ mutex_unlock(&eventfs_mutex);
+
+ return ei;
}
/**
- * eventfs_create_events_dir - create the trace event structure
- * @name: the name of the directory to create.
- * @parent: parent dentry for this file. This should be a directory dentry
- * if set. If this parameter is NULL, then the directory will be
- * created in the root of the tracefs filesystem.
+ * eventfs_create_events_dir - create the top level events directory
+ * @name: The name of the top level directory to create.
+ * @parent: Parent dentry for this file in the tracefs directory.
+ * @entries: A list of entries that represent the files under this directory
+ * @size: The number of @entries
+ * @data: The default data to pass to the files (an entry may override it).
*
* This function creates the top of the trace event directory.
*/
-struct dentry *eventfs_create_events_dir(const char *name,
- struct dentry *parent)
+struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry *parent,
+ const struct eventfs_entry *entries,
+ int size, void *data)
{
struct dentry *dentry = tracefs_start_creating(name, parent);
struct eventfs_inode *ei;
@@ -581,19 +731,32 @@ struct dentry *eventfs_create_events_dir(const char *name,
return NULL;
if (IS_ERR(dentry))
- return dentry;
+ return (struct eventfs_inode *)dentry;
ei = kzalloc(sizeof(*ei), GFP_KERNEL);
if (!ei)
- return ERR_PTR(-ENOMEM);
+ goto fail;
+
inode = tracefs_get_inode(dentry->d_sb);
- if (unlikely(!inode)) {
- kfree(ei);
- tracefs_failed_creating(dentry);
- return ERR_PTR(-ENOMEM);
+ if (unlikely(!inode))
+ goto fail;
+
+ if (size) {
+ ei->d_children = kzalloc(sizeof(*ei->d_children) * size, GFP_KERNEL);
+ if (!ei->d_children)
+ goto fail;
}
- INIT_LIST_HEAD(&ei->e_top_files);
+ ei->dentry = dentry;
+ ei->entries = entries;
+ ei->nr_entries = size;
+ ei->data = data;
+ ei->name = kstrdup_const(name, GFP_KERNEL);
+ if (!ei->name)
+ goto fail;
+
+ INIT_LIST_HEAD(&ei->children);
+ INIT_LIST_HEAD(&ei->list);
ti = get_tracefs(inode);
ti->flags |= TRACEFS_EVENT_INODE | TRACEFS_EVENT_TOP_INODE;
@@ -608,193 +771,41 @@ struct dentry *eventfs_create_events_dir(const char *name,
d_instantiate(dentry, inode);
inc_nlink(dentry->d_parent->d_inode);
fsnotify_mkdir(dentry->d_parent->d_inode, dentry);
- return tracefs_end_creating(dentry);
-}
+ tracefs_end_creating(dentry);
-/**
- * eventfs_add_subsystem_dir - add eventfs subsystem_dir to list to create later
- * @name: the name of the file to create.
- * @parent: parent dentry for this dir.
- *
- * This function adds eventfs subsystem dir to list.
- * And all these dirs are created on the fly when they are looked up,
- * and the dentry and inodes will be removed when they are done.
- */
-struct eventfs_file *eventfs_add_subsystem_dir(const char *name,
- struct dentry *parent)
-{
- struct tracefs_inode *ti_parent;
- struct eventfs_inode *ei_parent;
- struct eventfs_file *ef;
+ /* Will call dput when the directory is removed */
+ dget(dentry);
- if (security_locked_down(LOCKDOWN_TRACEFS))
- return NULL;
-
- if (!parent)
- return ERR_PTR(-EINVAL);
-
- ti_parent = get_tracefs(parent->d_inode);
- ei_parent = ti_parent->private;
+ return ei;
- ef = eventfs_prepare_ef(name, S_IFDIR, NULL, NULL, NULL);
- if (IS_ERR(ef))
- return ef;
-
- mutex_lock(&eventfs_mutex);
- list_add_tail(&ef->list, &ei_parent->e_top_files);
- ef->d_parent = parent;
- mutex_unlock(&eventfs_mutex);
- return ef;
+ fail:
+ kfree(ei->d_children);
+ kfree(ei);
+ tracefs_failed_creating(dentry);
+ return ERR_PTR(-ENOMEM);
}
-/**
- * eventfs_add_dir - add eventfs dir to list to create later
- * @name: the name of the file to create.
- * @ef_parent: parent eventfs_file for this dir.
- *
- * This function adds eventfs dir to list.
- * And all these dirs are created on the fly when they are looked up,
- * and the dentry and inodes will be removed when they are done.
- */
-struct eventfs_file *eventfs_add_dir(const char *name,
- struct eventfs_file *ef_parent)
+static void free_ei(struct rcu_head *head)
{
- struct eventfs_file *ef;
-
- if (security_locked_down(LOCKDOWN_TRACEFS))
- return NULL;
+ struct eventfs_inode *ei = container_of(head, struct eventfs_inode, rcu);
- if (!ef_parent)
- return ERR_PTR(-EINVAL);
-
- ef = eventfs_prepare_ef(name, S_IFDIR, NULL, NULL, NULL);
- if (IS_ERR(ef))
- return ef;
-
- mutex_lock(&eventfs_mutex);
- list_add_tail(&ef->list, &ef_parent->ei->e_top_files);
- ef->d_parent = ef_parent->dentry;
- mutex_unlock(&eventfs_mutex);
- return ef;
-}
-
-/**
- * eventfs_add_events_file - add the data needed to create a file for later reference
- * @name: the name of the file to create.
- * @mode: the permission that the file should have.
- * @parent: parent dentry for this file.
- * @data: something that the caller will want to get to later on.
- * @fop: struct file_operations that should be used for this file.
- *
- * This function is used to add the information needed to create a
- * dentry/inode within the top level events directory. The file created
- * will have the @mode permissions. The @data will be used to fill the
- * inode.i_private when the open() call is done. The dentry and inodes are
- * all created when they are referenced, and removed when they are no
- * longer referenced.
- */
-int eventfs_add_events_file(const char *name, umode_t mode,
- struct dentry *parent, void *data,
- const struct file_operations *fop)
-{
- struct tracefs_inode *ti;
- struct eventfs_inode *ei;
- struct eventfs_file *ef;
-
- if (security_locked_down(LOCKDOWN_TRACEFS))
- return -ENODEV;
-
- if (!parent)
- return -EINVAL;
-
- if (!(mode & S_IFMT))
- mode |= S_IFREG;
-
- if (!parent->d_inode)
- return -EINVAL;
-
- ti = get_tracefs(parent->d_inode);
- if (!(ti->flags & TRACEFS_EVENT_INODE))
- return -EINVAL;
-
- ei = ti->private;
- ef = eventfs_prepare_ef(name, mode, fop, NULL, data);
-
- if (IS_ERR(ef))
- return -ENOMEM;
-
- mutex_lock(&eventfs_mutex);
- list_add_tail(&ef->list, &ei->e_top_files);
- ef->d_parent = parent;
- mutex_unlock(&eventfs_mutex);
- return 0;
-}
-
-/**
- * eventfs_add_file - add eventfs file to list to create later
- * @name: the name of the file to create.
- * @mode: the permission that the file should have.
- * @ef_parent: parent eventfs_file for this file.
- * @data: something that the caller will want to get to later on.
- * @fop: struct file_operations that should be used for this file.
- *
- * This function is used to add the information needed to create a
- * file within a subdirectory of the events directory. The file created
- * will have the @mode permissions. The @data will be used to fill the
- * inode.i_private when the open() call is done. The dentry and inodes are
- * all created when they are referenced, and removed when they are no
- * longer referenced.
- */
-int eventfs_add_file(const char *name, umode_t mode,
- struct eventfs_file *ef_parent,
- void *data,
- const struct file_operations *fop)
-{
- struct eventfs_file *ef;
-
- if (security_locked_down(LOCKDOWN_TRACEFS))
- return -ENODEV;
-
- if (!ef_parent)
- return -EINVAL;
-
- if (!(mode & S_IFMT))
- mode |= S_IFREG;
-
- ef = eventfs_prepare_ef(name, mode, fop, NULL, data);
- if (IS_ERR(ef))
- return -ENOMEM;
-
- mutex_lock(&eventfs_mutex);
- list_add_tail(&ef->list, &ef_parent->ei->e_top_files);
- ef->d_parent = ef_parent->dentry;
- mutex_unlock(&eventfs_mutex);
- return 0;
-}
-
-static void free_ef(struct rcu_head *head)
-{
- struct eventfs_file *ef = container_of(head, struct eventfs_file, rcu);
-
- kfree(ef->name);
- kfree(ef->ei);
- kfree(ef);
+ kfree_const(ei->name);
+ kfree(ei->d_children);
+ kfree(ei);
}
/**
* eventfs_remove_rec - remove eventfs dir or file from list
- * @ef: eventfs_file to be removed.
- * @head: to create list of eventfs_file to be deleted
- * @level: to check recursion depth
+ * @ei: eventfs_inode to be removed.
*
- * The helper function eventfs_remove_rec() is used to clean up and free the
- * associated data from eventfs for both of the added functions.
+ * This function recursively remove eventfs_inode which
+ * contains info of file or dir.
*/
-static void eventfs_remove_rec(struct eventfs_file *ef, struct list_head *head, int level)
+static void eventfs_remove_rec(struct eventfs_inode *ei, struct list_head *head, int level)
{
- struct eventfs_file *ef_child;
+ struct eventfs_inode *ei_child;
- if (!ef)
+ if (!ei)
return;
/*
* Check recursion depth. It should never be greater than 3:
@@ -806,62 +817,68 @@ static void eventfs_remove_rec(struct eventfs_file *ef, struct list_head *head,
if (WARN_ON_ONCE(level > 3))
return;
- if (ef->ei) {
- /* search for nested folders or files */
- list_for_each_entry_srcu(ef_child, &ef->ei->e_top_files, list,
- lockdep_is_held(&eventfs_mutex)) {
- eventfs_remove_rec(ef_child, head, level + 1);
- }
+ /* search for nested folders or files */
+ list_for_each_entry_srcu(ei_child, &ei->children, list,
+ lockdep_is_held(&eventfs_mutex)) {
+ eventfs_remove_rec(ei_child, head, level + 1);
}
- list_del_rcu(&ef->list);
- list_add_tail(&ef->del_list, head);
+ list_del_rcu(&ei->list);
+ list_add_tail(&ei->del_list, head);
}
+static void unhook_dentry(struct dentry **dentry, struct dentry **list)
+{
+ if (*dentry) {
+ unsigned long ptr = (unsigned long)*list;
+
+ /* Keep the dentry from being freed yet */
+ dget(*dentry);
+
+ /*
+ * Paranoid: The dget() above should prevent the dentry
+ * from being freed and calling eventfs_set_ei_status_free().
+ * But just in case, set the link list LSB pointer to 1
+ * and have eventfs_set_ei_status_free() check that to
+ * make sure that if it does happen, it will not think
+ * the d_fsdata is an eventfs_inode.
+ *
+ * For this to work, no eventfs_inode should be allocated
+ * on a odd space, as the ef should always be allocated
+ * to be at least word aligned. Check for that too.
+ */
+ WARN_ON_ONCE(ptr & 1);
+
+ (*dentry)->d_fsdata = (void *)(ptr | 1);
+ *list = *dentry;
+ *dentry = NULL;
+ }
+}
/**
* eventfs_remove - remove eventfs dir or file from list
- * @ef: eventfs_file to be removed.
+ * @ei: eventfs_inode to be removed.
*
* This function acquire the eventfs_mutex lock and call eventfs_remove_rec()
*/
-void eventfs_remove(struct eventfs_file *ef)
+void eventfs_remove_dir(struct eventfs_inode *ei)
{
- struct eventfs_file *tmp;
- LIST_HEAD(ef_del_list);
+ struct eventfs_inode *tmp;
+ LIST_HEAD(ei_del_list);
struct dentry *dentry_list = NULL;
struct dentry *dentry;
+ int i;
- if (!ef)
+ if (!ei)
return;
mutex_lock(&eventfs_mutex);
- eventfs_remove_rec(ef, &ef_del_list, 0);
- list_for_each_entry_safe(ef, tmp, &ef_del_list, del_list) {
- if (ef->dentry) {
- unsigned long ptr = (unsigned long)dentry_list;
-
- /* Keep the dentry from being freed yet */
- dget(ef->dentry);
-
- /*
- * Paranoid: The dget() above should prevent the dentry
- * from being freed and calling eventfs_set_ef_status_free().
- * But just in case, set the link list LSB pointer to 1
- * and have eventfs_set_ef_status_free() check that to
- * make sure that if it does happen, it will not think
- * the d_fsdata is an event_file.
- *
- * For this to work, no event_file should be allocated
- * on a odd space, as the ef should always be allocated
- * to be at least word aligned. Check for that too.
- */
- WARN_ON_ONCE(ptr & 1);
-
- ef->dentry->d_fsdata = (void *)(ptr | 1);
- dentry_list = ef->dentry;
- ef->dentry = NULL;
- }
- call_srcu(&eventfs_srcu, &ef->rcu, free_ef);
+ eventfs_remove_rec(ei, &ei_del_list, 0);
+
+ list_for_each_entry_safe(ei, tmp, &ei_del_list, del_list) {
+ for (i = 0; i < ei->nr_entries; i++)
+ unhook_dentry(&ei->d_children[i], &dentry_list);
+ unhook_dentry(&ei->dentry, &dentry_list);
+ call_srcu(&eventfs_srcu, &ei->rcu, free_ei);
}
mutex_unlock(&eventfs_mutex);
@@ -876,8 +893,8 @@ void eventfs_remove(struct eventfs_file *ef)
mutex_lock(&eventfs_mutex);
/* dentry should now have at least a single reference */
WARN_ONCE((int)d_count(dentry) < 1,
- "dentry %p less than one reference (%d) after invalidate\n",
- dentry, d_count(dentry));
+ "dentry %px (%s) less than one reference (%d) after invalidate\n",
+ dentry, dentry->d_name.name, d_count(dentry));
mutex_unlock(&eventfs_mutex);
dput(dentry);
}
@@ -385,7 +385,7 @@ static void tracefs_dentry_iput(struct dentry *dentry, struct inode *inode)
ti = get_tracefs(inode);
if (ti && ti->flags & TRACEFS_EVENT_INODE)
- eventfs_set_ef_status_free(ti, dentry);
+ eventfs_set_ei_status_free(ti, dentry);
iput(inode);
}
@@ -13,6 +13,41 @@ struct tracefs_inode {
struct inode vfs_inode;
};
+/*
+ * struct eventfs_inode - hold the properties of the eventfs directories.
+ * @list: link list into the parent directory
+ * @entries: the array of entries representing the files in the directory
+ * @name: the name of the directory to create
+ * @children: link list into the child eventfs_inode
+ * @dentry: the dentry of the directory
+ * @d_parent: pointer to the parent's dentry
+ * @d_children: The array of dentries to represent the files when created
+ * @data: The private data to pass to the callbacks
+ * @nr_entries: The number of items in @entries
+ */
+struct eventfs_inode {
+ struct list_head list;
+ const struct eventfs_entry *entries;
+ const char *name;
+ struct list_head children;
+ struct dentry *dentry;
+ struct dentry *d_parent;
+ struct dentry **d_children;
+ void *data;
+ /*
+ * Union - used for deletion
+ * @del_list: list of eventfs_inode to delete
+ * @rcu: eventfs_indoe to delete in RCU
+ * @is_freed: node is freed if one of the above is set
+ */
+ union {
+ struct list_head del_list;
+ struct rcu_head rcu;
+ unsigned long is_freed;
+ };
+ int nr_entries;
+};
+
static inline struct tracefs_inode *get_tracefs(const struct inode *inode)
{
return container_of(inode, struct tracefs_inode, vfs_inode);
@@ -25,6 +60,6 @@ struct inode *tracefs_get_inode(struct super_block *sb);
struct dentry *eventfs_start_creating(const char *name, struct dentry *parent);
struct dentry *eventfs_failed_creating(struct dentry *dentry);
struct dentry *eventfs_end_creating(struct dentry *dentry);
-void eventfs_set_ef_status_free(struct tracefs_inode *ti, struct dentry *dentry);
+void eventfs_set_ei_status_free(struct tracefs_inode *ti, struct dentry *dentry);
#endif /* _TRACEFS_INTERNAL_H */
@@ -652,7 +652,7 @@ struct trace_event_file {
struct list_head list;
struct trace_event_call *event_call;
struct event_filter __rcu *filter;
- struct eventfs_file *ef;
+ struct eventfs_inode *ei;
struct trace_array *tr;
struct trace_subsystem_dir *system;
struct list_head triggers;
@@ -23,26 +23,25 @@ struct file_operations;
struct eventfs_file;
-struct dentry *eventfs_create_events_dir(const char *name,
- struct dentry *parent);
+typedef int (*eventfs_callback)(const char *name, umode_t *mode, void **data,
+ const struct file_operations **fops);
-struct eventfs_file *eventfs_add_subsystem_dir(const char *name,
- struct dentry *parent);
+struct eventfs_entry {
+ const char *name;
+ eventfs_callback callback;
+};
-struct eventfs_file *eventfs_add_dir(const char *name,
- struct eventfs_file *ef_parent);
+struct eventfs_inode;
-int eventfs_add_file(const char *name, umode_t mode,
- struct eventfs_file *ef_parent, void *data,
- const struct file_operations *fops);
+struct eventfs_inode *eventfs_create_events_dir(const char *name, struct dentry *parent,
+ const struct eventfs_entry *entries,
+ int size, void *data);
-int eventfs_add_events_file(const char *name, umode_t mode,
- struct dentry *parent, void *data,
- const struct file_operations *fops);
+struct eventfs_inode *eventfs_create_dir(const char *name, struct eventfs_inode *parent,
+ const struct eventfs_entry *entries,
+ int size, void *data);
-void eventfs_remove(struct eventfs_file *ef);
-
-void eventfs_remove_events_dir(struct dentry *dentry);
+void eventfs_remove_dir(struct eventfs_inode *ei);
struct dentry *tracefs_create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
@@ -9758,7 +9758,6 @@ static __init void create_trace_instances(struct dentry *d_tracer)
static void
init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
{
- struct trace_event_file *file;
int cpu;
trace_create_file("available_tracers", TRACE_MODE_READ, d_tracer,
@@ -9791,11 +9790,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
trace_create_file("trace_marker", 0220, d_tracer,
tr, &tracing_mark_fops);
- file = __find_event_file(tr, "ftrace", "print");
- if (file && file->ef)
- eventfs_add_file("trigger", TRACE_MODE_WRITE, file->ef,
- file, &event_trigger_fops);
- tr->trace_marker_file = file;
+ tr->trace_marker_file = __find_event_file(tr, "ftrace", "print");
trace_create_file("trace_marker_raw", 0220, d_tracer,
tr, &tracing_mark_raw_fops);
@@ -381,7 +381,7 @@ struct trace_array {
struct dentry *dir;
struct dentry *options;
struct dentry *percpu_dir;
- struct dentry *event_dir;
+ struct eventfs_inode *event_dir;
struct trace_options *topts;
struct list_head systems;
struct list_head events;
@@ -1345,7 +1345,7 @@ struct trace_subsystem_dir {
struct list_head list;
struct event_subsystem *subsystem;
struct trace_array *tr;
- struct eventfs_file *ef;
+ struct eventfs_inode *ei;
int ref_count;
int nr_events;
};
@@ -984,7 +984,7 @@ static void remove_subsystem(struct trace_subsystem_dir *dir)
return;
if (!--dir->nr_events) {
- eventfs_remove(dir->ef);
+ eventfs_remove_dir(dir->ei);
list_del(&dir->list);
__put_system_dir(dir);
}
@@ -1013,7 +1013,7 @@ void event_file_put(struct trace_event_file *file)
static void remove_event_file_dir(struct trace_event_file *file)
{
- eventfs_remove(file->ef);
+ eventfs_remove_dir(file->ei);
list_del(&file->list);
remove_subsystem(file->system);
free_event_filter(file->filter);
@@ -2302,14 +2302,40 @@ create_new_subsystem(const char *name)
return NULL;
}
-static struct eventfs_file *
+int system_callback(const char *name, umode_t *mode, void **data,
+ const struct file_operations **fops)
+{
+ if (strcmp(name, "filter") == 0)
+ *fops = &ftrace_subsystem_filter_fops;
+
+ else if (strcmp(name, "enable") == 0)
+ *fops = &ftrace_system_enable_fops;
+
+ else
+ return 0;
+
+ *mode = TRACE_MODE_WRITE;
+ return 1;
+}
+
+static struct eventfs_inode *
event_subsystem_dir(struct trace_array *tr, const char *name,
- struct trace_event_file *file, struct dentry *parent)
+ struct trace_event_file *file, struct eventfs_inode *parent)
{
struct event_subsystem *system, *iter;
struct trace_subsystem_dir *dir;
- struct eventfs_file *ef;
- int res;
+ struct eventfs_inode *ei;
+ int nr_entries;
+ static struct eventfs_entry system_entries[] = {
+ {
+ .name = "filter",
+ .callback = system_callback,
+ },
+ {
+ .name = "enable",
+ .callback = system_callback,
+ }
+ };
/* First see if we did not already create this dir */
list_for_each_entry(dir, &tr->systems, list) {
@@ -2317,7 +2343,7 @@ event_subsystem_dir(struct trace_array *tr, const char *name,
if (strcmp(system->name, name) == 0) {
dir->nr_events++;
file->system = dir;
- return dir->ef;
+ return dir->ei;
}
}
@@ -2341,39 +2367,29 @@ event_subsystem_dir(struct trace_array *tr, const char *name,
} else
__get_system(system);
- ef = eventfs_add_subsystem_dir(name, parent);
- if (IS_ERR(ef)) {
+ /* ftrace only has directories no files */
+ if (strcmp(name, "ftrace") == 0)
+ nr_entries = 0;
+ else
+ nr_entries = ARRAY_SIZE(system_entries);
+
+ ei = eventfs_create_dir(name, parent, system_entries, nr_entries, dir);
+ if (!ei) {
pr_warn("Failed to create system directory %s\n", name);
__put_system(system);
goto out_free;
}
- dir->ef = ef;
+ dir->ei = ei;
dir->tr = tr;
dir->ref_count = 1;
dir->nr_events = 1;
dir->subsystem = system;
file->system = dir;
- /* the ftrace system is special, do not create enable or filter files */
- if (strcmp(name, "ftrace") != 0) {
-
- res = eventfs_add_file("filter", TRACE_MODE_WRITE,
- dir->ef, dir,
- &ftrace_subsystem_filter_fops);
- if (res) {
- kfree(system->filter);
- system->filter = NULL;
- pr_warn("Could not create tracefs '%s/filter' entry\n", name);
- }
-
- eventfs_add_file("enable", TRACE_MODE_WRITE, dir->ef, dir,
- &ftrace_system_enable_fops);
- }
-
list_add(&dir->list, &tr->systems);
- return dir->ef;
+ return dir->ei;
out_free:
kfree(dir);
@@ -2422,15 +2438,134 @@ event_define_fields(struct trace_event_call *call)
return ret;
}
+static int event_callback(const char *name, umode_t *mode, void **data,
+ const struct file_operations **fops)
+{
+ struct trace_event_file *file = *data;
+ struct trace_event_call *call = file->event_call;
+
+ if (strcmp(name, "format") == 0) {
+ *mode = TRACE_MODE_READ;
+ *fops = &ftrace_event_format_fops;
+ *data = call;
+ return 1;
+ }
+
+ /*
+ * Only event directories that can be enabled should have
+ * triggers or filters, with the exception of the "print"
+ * event that can have a "trigger" file.
+ */
+ if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
+ if (call->class->reg && strcmp(name, "enable") == 0) {
+ *mode = TRACE_MODE_WRITE;
+ *fops = &ftrace_enable_fops;
+ return 1;
+ }
+
+ if (strcmp(name, "filter") == 0) {
+ *mode = TRACE_MODE_WRITE;
+ *fops = &ftrace_event_filter_fops;
+ return 1;
+ }
+ }
+
+ if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE) ||
+ strcmp(trace_event_name(call), "print") == 0) {
+ if (strcmp(name, "trigger") == 0) {
+ *mode = TRACE_MODE_WRITE;
+ *fops = &event_trigger_fops;
+ return 1;
+ }
+ }
+
+#ifdef CONFIG_PERF_EVENTS
+ if (call->event.type && call->class->reg &&
+ strcmp(name, "id") == 0) {
+ *mode = TRACE_MODE_READ;
+ *data = (void *)(long)call->event.type;
+ *fops = &ftrace_event_id_fops;
+ return 1;
+ }
+#endif
+
+#ifdef CONFIG_HIST_TRIGGERS
+ if (strcmp(name, "hist") == 0) {
+ *mode = TRACE_MODE_READ;
+ *fops = &event_hist_fops;
+ return 1;
+ }
+#endif
+#ifdef CONFIG_HIST_TRIGGERS_DEBUG
+ if (strcmp(name, "hist_debug") == 0) {
+ *mode = TRACE_MODE_READ;
+ *fops = &event_hist_debug_fops;
+ return 1;
+ }
+#endif
+#ifdef CONFIG_TRACE_EVENT_INJECT
+ if (call->event.type && call->class->reg &&
+ strcmp(name, "inject") == 0) {
+ *mode = 0200;
+ *fops = &event_inject_fops;
+ return 1;
+ }
+#endif
+ return 0;
+}
+
static int
-event_create_dir(struct dentry *parent, struct trace_event_file *file)
+event_create_dir(struct eventfs_inode *parent, struct trace_event_file *file)
{
struct trace_event_call *call = file->event_call;
- struct eventfs_file *ef_subsystem = NULL;
struct trace_array *tr = file->tr;
- struct eventfs_file *ef;
+ struct eventfs_inode *e_events;
+ struct eventfs_inode *ei;
const char *name;
+ int nr_entries;
int ret;
+ static struct eventfs_entry event_entries[] = {
+ {
+ .name = "enable",
+ .callback = event_callback,
+ },
+ {
+ .name = "filter",
+ .callback = event_callback,
+ },
+ {
+ .name = "trigger",
+ .callback = event_callback,
+ },
+ {
+ .name = "format",
+ .callback = event_callback,
+ },
+#ifdef CONFIG_PERF_EVENTS
+ {
+ .name = "id",
+ .callback = event_callback,
+ },
+#endif
+#ifdef CONFIG_HIST_TRIGGERS
+ {
+ .name = "hist",
+ .callback = event_callback,
+ },
+#endif
+#ifdef CONFIG_HIST_TRIGGERS_DEBUG
+ {
+ .name = "hist_debug",
+ .callback = event_callback,
+ },
+#endif
+#ifdef CONFIG_TRACE_EVENT_INJECT
+ {
+ .name = "inject",
+ .callback = event_callback,
+ },
+#endif
+ };
/*
* If the trace point header did not define TRACE_SYSTEM
@@ -2440,29 +2575,20 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file)
if (WARN_ON_ONCE(strcmp(call->class->system, TRACE_SYSTEM) == 0))
return -ENODEV;
- ef_subsystem = event_subsystem_dir(tr, call->class->system, file, parent);
- if (!ef_subsystem)
+ e_events = event_subsystem_dir(tr, call->class->system, file, parent);
+ if (!e_events)
return -ENOMEM;
+ nr_entries = ARRAY_SIZE(event_entries);
+
name = trace_event_name(call);
- ef = eventfs_add_dir(name, ef_subsystem);
- if (IS_ERR(ef)) {
+ ei = eventfs_create_dir(name, e_events, event_entries, nr_entries, file);
+ if (IS_ERR(ei)) {
pr_warn("Could not create tracefs '%s' directory\n", name);
return -1;
}
- file->ef = ef;
-
- if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
- eventfs_add_file("enable", TRACE_MODE_WRITE, file->ef, file,
- &ftrace_enable_fops);
-
-#ifdef CONFIG_PERF_EVENTS
- if (call->event.type && call->class->reg)
- eventfs_add_file("id", TRACE_MODE_READ, file->ef,
- (void *)(long)call->event.type,
- &ftrace_event_id_fops);
-#endif
+ file->ei = ei;
ret = event_define_fields(call);
if (ret < 0) {
@@ -2470,35 +2596,6 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file)
return ret;
}
- /*
- * Only event directories that can be enabled should have
- * triggers or filters.
- */
- if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE)) {
- eventfs_add_file("filter", TRACE_MODE_WRITE, file->ef,
- file, &ftrace_event_filter_fops);
-
- eventfs_add_file("trigger", TRACE_MODE_WRITE, file->ef,
- file, &event_trigger_fops);
- }
-
-#ifdef CONFIG_HIST_TRIGGERS
- eventfs_add_file("hist", TRACE_MODE_READ, file->ef, file,
- &event_hist_fops);
-#endif
-#ifdef CONFIG_HIST_TRIGGERS_DEBUG
- eventfs_add_file("hist_debug", TRACE_MODE_READ, file->ef, file,
- &event_hist_debug_fops);
-#endif
- eventfs_add_file("format", TRACE_MODE_READ, file->ef, call,
- &ftrace_event_format_fops);
-
-#ifdef CONFIG_TRACE_EVENT_INJECT
- if (call->event.type && call->class->reg)
- eventfs_add_file("inject", 0200, file->ef, file,
- &event_inject_fops);
-#endif
-
return 0;
}
@@ -3644,30 +3741,65 @@ static __init int setup_trace_event(char *str)
}
__setup("trace_event=", setup_trace_event);
+static int events_callback(const char *name, umode_t *mode, void **data,
+ const struct file_operations **fops)
+{
+ if (strcmp(name, "enable") == 0) {
+ *mode = TRACE_MODE_WRITE;
+ *fops = &ftrace_tr_enable_fops;
+ return 1;
+ }
+
+ if (strcmp(name, "header_page") == 0)
+ *data = ring_buffer_print_page_header;
+
+ else if (strcmp(name, "header_event") == 0)
+ *data = ring_buffer_print_entry_header;
+
+ else
+ return 0;
+
+ *mode = TRACE_MODE_READ;
+ *fops = &ftrace_show_header_fops;
+ return 1;
+}
+
/* Expects to have event_mutex held when called */
static int
create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
{
- struct dentry *d_events;
+ struct eventfs_inode *e_events;
struct dentry *entry;
- int error = 0;
+ int nr_entries;
+ static struct eventfs_entry events_entries[] = {
+ {
+ .name = "enable",
+ .callback = events_callback,
+ },
+ {
+ .name = "header_page",
+ .callback = events_callback,
+ },
+ {
+ .name = "header_event",
+ .callback = events_callback,
+ },
+ };
entry = trace_create_file("set_event", TRACE_MODE_WRITE, parent,
tr, &ftrace_set_event_fops);
if (!entry)
return -ENOMEM;
- d_events = eventfs_create_events_dir("events", parent);
- if (IS_ERR(d_events)) {
+ nr_entries = ARRAY_SIZE(events_entries);
+
+ e_events = eventfs_create_events_dir("events", parent, events_entries,
+ nr_entries, tr);
+ if (IS_ERR(e_events)) {
pr_warn("Could not create tracefs 'events' directory\n");
return -ENOMEM;
}
- error = eventfs_add_events_file("enable", TRACE_MODE_WRITE, d_events,
- tr, &ftrace_tr_enable_fops);
- if (error)
- return -ENOMEM;
-
/* There are not as crucial, just warn if they are not created */
trace_create_file("set_event_pid", TRACE_MODE_WRITE, parent,
@@ -3677,16 +3809,7 @@ create_event_toplevel_files(struct dentry *parent, struct trace_array *tr)
TRACE_MODE_WRITE, parent, tr,
&ftrace_set_event_notrace_pid_fops);
- /* ring buffer internal formats */
- eventfs_add_events_file("header_page", TRACE_MODE_READ, d_events,
- ring_buffer_print_page_header,
- &ftrace_show_header_fops);
-
- eventfs_add_events_file("header_event", TRACE_MODE_READ, d_events,
- ring_buffer_print_entry_header,
- &ftrace_show_header_fops);
-
- tr->event_dir = d_events;
+ tr->event_dir = e_events;
return 0;
}
@@ -3770,7 +3893,7 @@ int event_trace_del_tracer(struct trace_array *tr)
down_write(&trace_event_sem);
__trace_remove_event_dirs(tr);
- eventfs_remove_events_dir(tr->event_dir);
+ eventfs_remove_dir(tr->event_dir);
up_write(&trace_event_sem);
tr->event_dir = NULL;