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c3d2d45b06
It is expected that most callers should _ignore_ the errors return by debugfs_create_dir() in err_inject_init(). Link: https://lkml.kernel.org/r/20230713082455.2415-1-machel@vivo.com Signed-off-by: Wang Ming <machel@vivo.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
100 lines
2.5 KiB
C
100 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/module.h>
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#include "notifier-error-inject.h"
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static int debugfs_errno_set(void *data, u64 val)
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{
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*(int *)data = clamp_t(int, val, -MAX_ERRNO, 0);
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return 0;
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}
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static int debugfs_errno_get(void *data, u64 *val)
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{
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*val = *(int *)data;
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return 0;
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}
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DEFINE_SIMPLE_ATTRIBUTE_SIGNED(fops_errno, debugfs_errno_get, debugfs_errno_set,
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"%lld\n");
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static struct dentry *debugfs_create_errno(const char *name, umode_t mode,
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struct dentry *parent, int *value)
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{
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return debugfs_create_file(name, mode, parent, value, &fops_errno);
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}
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static int notifier_err_inject_callback(struct notifier_block *nb,
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unsigned long val, void *p)
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{
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int err = 0;
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struct notifier_err_inject *err_inject =
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container_of(nb, struct notifier_err_inject, nb);
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struct notifier_err_inject_action *action;
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for (action = err_inject->actions; action->name; action++) {
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if (action->val == val) {
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err = action->error;
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break;
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}
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}
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if (err)
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pr_info("Injecting error (%d) to %s\n", err, action->name);
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return notifier_from_errno(err);
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}
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struct dentry *notifier_err_inject_dir;
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EXPORT_SYMBOL_GPL(notifier_err_inject_dir);
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struct dentry *notifier_err_inject_init(const char *name, struct dentry *parent,
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struct notifier_err_inject *err_inject, int priority)
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{
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struct notifier_err_inject_action *action;
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umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
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struct dentry *dir;
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struct dentry *actions_dir;
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err_inject->nb.notifier_call = notifier_err_inject_callback;
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err_inject->nb.priority = priority;
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dir = debugfs_create_dir(name, parent);
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actions_dir = debugfs_create_dir("actions", dir);
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for (action = err_inject->actions; action->name; action++) {
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struct dentry *action_dir;
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action_dir = debugfs_create_dir(action->name, actions_dir);
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/*
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* Create debugfs r/w file containing action->error. If
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* notifier call chain is called with action->val, it will
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* fail with the error code
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*/
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debugfs_create_errno("error", mode, action_dir, &action->error);
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}
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return dir;
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}
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EXPORT_SYMBOL_GPL(notifier_err_inject_init);
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static int __init err_inject_init(void)
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{
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notifier_err_inject_dir =
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debugfs_create_dir("notifier-error-inject", NULL);
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return 0;
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}
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static void __exit err_inject_exit(void)
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{
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debugfs_remove_recursive(notifier_err_inject_dir);
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}
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module_init(err_inject_init);
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module_exit(err_inject_exit);
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MODULE_DESCRIPTION("Notifier error injection module");
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
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