Merge tag 'powerpc-6.6-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc...

[platform/kernel/linux-rpi.git] / fs / tracefs / event_inode.c

diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index 9f64e73..8c8d64e 100644 (file)
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -70,6 +70,7 @@ static struct dentry *eventfs_root_lookup(struct inode *dir,
                                          struct dentry *dentry,
                                          unsigned int flags);
 static int dcache_dir_open_wrapper(struct inode *inode, struct file *file);
+static int dcache_readdir_wrapper(struct file *file, struct dir_context *ctx);
 static int eventfs_release(struct inode *inode, struct file *file);
 
 static const struct inode_operations eventfs_root_dir_inode_operations = {
@@ -79,7 +80,7 @@ static const struct inode_operations eventfs_root_dir_inode_operations = {
 static const struct file_operations eventfs_file_operations = {
        .open           = dcache_dir_open_wrapper,
        .read           = generic_read_dir,
-       .iterate_shared = dcache_readdir,
+       .iterate_shared = dcache_readdir_wrapper,
        .llseek         = generic_file_llseek,
        .release        = eventfs_release,
 };
@@ -396,6 +397,11 @@ static struct dentry *eventfs_root_lookup(struct inode *dir,
        return ret;
 }
 
+struct dentry_list {
+       void                    *cursor;
+       struct dentry           **dentries;
+};
+
 /**
  * eventfs_release - called to release eventfs file/dir
  * @inode: inode to be released
@@ -404,26 +410,25 @@ static struct dentry *eventfs_root_lookup(struct inode *dir,
 static int eventfs_release(struct inode *inode, struct file *file)
 {
        struct tracefs_inode *ti;
-       struct eventfs_inode *ei;
-       struct eventfs_file *ef;
-       struct dentry *dentry;
-       int idx;
+       struct dentry_list *dlist = file->private_data;
+       void *cursor;
+       int i;
 
        ti = get_tracefs(inode);
        if (!(ti->flags & TRACEFS_EVENT_INODE))
                return -EINVAL;
 
-       ei = ti->private;
-       idx = srcu_read_lock(&eventfs_srcu);
-       list_for_each_entry_srcu(ef, &ei->e_top_files, list,
-                                srcu_read_lock_held(&eventfs_srcu)) {
-               mutex_lock(&eventfs_mutex);
-               dentry = ef->dentry;
-               mutex_unlock(&eventfs_mutex);
-               if (dentry)
-                       dput(dentry);
+       if (WARN_ON_ONCE(!dlist))
+               return -EINVAL;
+
+       for (i = 0; dlist->dentries && dlist->dentries[i]; i++) {
+               dput(dlist->dentries[i]);
        }
-       srcu_read_unlock(&eventfs_srcu, idx);
+
+       cursor = dlist->cursor;
+       kfree(dlist->dentries);
+       kfree(dlist);
+       file->private_data = cursor;
        return dcache_dir_close(inode, file);
 }
 
@@ -442,22 +447,70 @@ static int dcache_dir_open_wrapper(struct inode *inode, struct file *file)
        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 *d;
        struct inode *f_inode = file_inode(file);
+       int cnt = 0;
        int idx;
+       int ret;
 
        ti = get_tracefs(f_inode);
        if (!(ti->flags & TRACEFS_EVENT_INODE))
                return -EINVAL;
 
+       if (WARN_ON_ONCE(file->private_data))
+               return -EINVAL;
+
+       dlist = kmalloc(sizeof(*dlist), GFP_KERNEL);
+       if (!dlist)
+               return -ENOMEM;
+
        ei = ti->private;
        idx = srcu_read_lock(&eventfs_srcu);
        list_for_each_entry_srcu(ef, &ei->e_top_files, list,
                                 srcu_read_lock_held(&eventfs_srcu)) {
-               create_dentry(ef, dentry, false);
+               d = create_dentry(ef, dentry, false);
+               if (d) {
+                       struct dentry **tmp;
+
+                       tmp = krealloc(dentries, sizeof(d) * (cnt + 2), GFP_KERNEL);
+                       if (!tmp)
+                               break;
+                       tmp[cnt] = d;
+                       tmp[cnt + 1] = NULL;
+                       cnt++;
+                       dentries = tmp;
+               }
        }
        srcu_read_unlock(&eventfs_srcu, idx);
-       return dcache_dir_open(inode, file);
+       ret = dcache_dir_open(inode, file);
+
+       /*
+        * dcache_dir_open() sets file->private_data to a dentry cursor.
+        * Need to save that but also save all the dentries that were
+        * opened by this function.
+        */
+       dlist->cursor = file->private_data;
+       dlist->dentries = dentries;
+       file->private_data = dlist;
+       return ret;
+}
+
+/*
+ * This just sets the file->private_data back to the cursor and back.
+ */
+static int dcache_readdir_wrapper(struct file *file, struct dir_context *ctx)
+{
+       struct dentry_list *dlist = file->private_data;
+       int ret;
+
+       file->private_data = dlist->cursor;
+       ret = dcache_readdir(file, ctx);
+       dlist->cursor = file->private_data;
+       file->private_data = dlist;
+       return ret;
 }
 
 /**