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-rw-r--r--mm/damon/dbgfs.c195
1 files changed, 193 insertions, 2 deletions
diff --git a/mm/damon/dbgfs.c b/mm/damon/dbgfs.c
index e850be4077f5..31ad550ecba2 100644
--- a/mm/damon/dbgfs.c
+++ b/mm/damon/dbgfs.c
@@ -18,6 +18,7 @@
static struct damon_ctx **dbgfs_ctxs;
static int dbgfs_nr_ctxs;
static struct dentry **dbgfs_dirs;
+static DEFINE_MUTEX(damon_dbgfs_lock);
/*
* Returns non-empty string on success, negative error code otherwise.
@@ -328,6 +329,186 @@ static struct damon_ctx *dbgfs_new_ctx(void)
return ctx;
}
+static void dbgfs_destroy_ctx(struct damon_ctx *ctx)
+{
+ damon_destroy_ctx(ctx);
+}
+
+/*
+ * Make a context of @name and create a debugfs directory for it.
+ *
+ * This function should be called while holding damon_dbgfs_lock.
+ *
+ * Returns 0 on success, negative error code otherwise.
+ */
+static int dbgfs_mk_context(char *name)
+{
+ struct dentry *root, **new_dirs, *new_dir;
+ struct damon_ctx **new_ctxs, *new_ctx;
+
+ if (damon_nr_running_ctxs())
+ return -EBUSY;
+
+ new_ctxs = krealloc(dbgfs_ctxs, sizeof(*dbgfs_ctxs) *
+ (dbgfs_nr_ctxs + 1), GFP_KERNEL);
+ if (!new_ctxs)
+ return -ENOMEM;
+ dbgfs_ctxs = new_ctxs;
+
+ new_dirs = krealloc(dbgfs_dirs, sizeof(*dbgfs_dirs) *
+ (dbgfs_nr_ctxs + 1), GFP_KERNEL);
+ if (!new_dirs)
+ return -ENOMEM;
+ dbgfs_dirs = new_dirs;
+
+ root = dbgfs_dirs[0];
+ if (!root)
+ return -ENOENT;
+
+ new_dir = debugfs_create_dir(name, root);
+ dbgfs_dirs[dbgfs_nr_ctxs] = new_dir;
+
+ new_ctx = dbgfs_new_ctx();
+ if (!new_ctx) {
+ debugfs_remove(new_dir);
+ dbgfs_dirs[dbgfs_nr_ctxs] = NULL;
+ return -ENOMEM;
+ }
+
+ dbgfs_ctxs[dbgfs_nr_ctxs] = new_ctx;
+ dbgfs_fill_ctx_dir(dbgfs_dirs[dbgfs_nr_ctxs],
+ dbgfs_ctxs[dbgfs_nr_ctxs]);
+ dbgfs_nr_ctxs++;
+
+ return 0;
+}
+
+static ssize_t dbgfs_mk_context_write(struct file *file,
+ const char __user *buf, size_t count, loff_t *ppos)
+{
+ char *kbuf;
+ char *ctx_name;
+ ssize_t ret = count;
+ int err;
+
+ kbuf = user_input_str(buf, count, ppos);
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+ ctx_name = kmalloc(count + 1, GFP_KERNEL);
+ if (!ctx_name) {
+ kfree(kbuf);
+ return -ENOMEM;
+ }
+
+ /* Trim white space */
+ if (sscanf(kbuf, "%s", ctx_name) != 1) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ mutex_lock(&damon_dbgfs_lock);
+ err = dbgfs_mk_context(ctx_name);
+ if (err)
+ ret = err;
+ mutex_unlock(&damon_dbgfs_lock);
+
+out:
+ kfree(kbuf);
+ kfree(ctx_name);
+ return ret;
+}
+
+/*
+ * Remove a context of @name and its debugfs directory.
+ *
+ * This function should be called while holding damon_dbgfs_lock.
+ *
+ * Return 0 on success, negative error code otherwise.
+ */
+static int dbgfs_rm_context(char *name)
+{
+ struct dentry *root, *dir, **new_dirs;
+ struct damon_ctx **new_ctxs;
+ int i, j;
+
+ if (damon_nr_running_ctxs())
+ return -EBUSY;
+
+ root = dbgfs_dirs[0];
+ if (!root)
+ return -ENOENT;
+
+ dir = debugfs_lookup(name, root);
+ if (!dir)
+ return -ENOENT;
+
+ new_dirs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_dirs),
+ GFP_KERNEL);
+ if (!new_dirs)
+ return -ENOMEM;
+
+ new_ctxs = kmalloc_array(dbgfs_nr_ctxs - 1, sizeof(*dbgfs_ctxs),
+ GFP_KERNEL);
+ if (!new_ctxs) {
+ kfree(new_dirs);
+ return -ENOMEM;
+ }
+
+ for (i = 0, j = 0; i < dbgfs_nr_ctxs; i++) {
+ if (dbgfs_dirs[i] == dir) {
+ debugfs_remove(dbgfs_dirs[i]);
+ dbgfs_destroy_ctx(dbgfs_ctxs[i]);
+ continue;
+ }
+ new_dirs[j] = dbgfs_dirs[i];
+ new_ctxs[j++] = dbgfs_ctxs[i];
+ }
+
+ kfree(dbgfs_dirs);
+ kfree(dbgfs_ctxs);
+
+ dbgfs_dirs = new_dirs;
+ dbgfs_ctxs = new_ctxs;
+ dbgfs_nr_ctxs--;
+
+ return 0;
+}
+
+static ssize_t dbgfs_rm_context_write(struct file *file,
+ const char __user *buf, size_t count, loff_t *ppos)
+{
+ char *kbuf;
+ ssize_t ret = count;
+ int err;
+ char *ctx_name;
+
+ kbuf = user_input_str(buf, count, ppos);
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+ ctx_name = kmalloc(count + 1, GFP_KERNEL);
+ if (!ctx_name) {
+ kfree(kbuf);
+ return -ENOMEM;
+ }
+
+ /* Trim white space */
+ if (sscanf(kbuf, "%s", ctx_name) != 1) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ mutex_lock(&damon_dbgfs_lock);
+ err = dbgfs_rm_context(ctx_name);
+ if (err)
+ ret = err;
+ mutex_unlock(&damon_dbgfs_lock);
+
+out:
+ kfree(kbuf);
+ kfree(ctx_name);
+ return ret;
+}
+
static ssize_t dbgfs_monitor_on_read(struct file *file,
char __user *buf, size_t count, loff_t *ppos)
{
@@ -370,6 +551,14 @@ static ssize_t dbgfs_monitor_on_write(struct file *file,
return ret;
}
+static const struct file_operations mk_contexts_fops = {
+ .write = dbgfs_mk_context_write,
+};
+
+static const struct file_operations rm_contexts_fops = {
+ .write = dbgfs_rm_context_write,
+};
+
static const struct file_operations monitor_on_fops = {
.read = dbgfs_monitor_on_read,
.write = dbgfs_monitor_on_write,
@@ -378,8 +567,10 @@ static const struct file_operations monitor_on_fops = {
static int __init __damon_dbgfs_init(void)
{
struct dentry *dbgfs_root;
- const char * const file_names[] = {"monitor_on"};
- const struct file_operations *fops[] = {&monitor_on_fops};
+ const char * const file_names[] = {"mk_contexts", "rm_contexts",
+ "monitor_on"};
+ const struct file_operations *fops[] = {&mk_contexts_fops,
+ &rm_contexts_fops, &monitor_on_fops};
int i;
dbgfs_root = debugfs_create_dir("damon", NULL);