Merge "vfs: Add support to debug umount failures" (4c60be87) · Commits · e / devices / android_kernel_xiaomi_nabu

fs/Kconfig

+5 −0

Original line number	Diff line number	Diff line
		@@ -309,4 +309,9 @@ endif # NETWORK_FILESYSTEMS
		source "fs/nls/Kconfig"
		source "fs/dlm/Kconfig"

		config FILE_TABLE_DEBUG
		bool "Enable FILE_TABLE_DEBUG"
		help
		This option enables debug of the open files using a global filetable

		endmenu

fs/file_table.c

+137 −0

Original line number	Diff line number	Diff line
		@@ -42,6 +42,141 @@ static struct kmem_cache *filp_cachep __read_mostly;

		static struct percpu_counter nr_files __cacheline_aligned_in_smp;

		#ifdef CONFIG_FILE_TABLE_DEBUG
		#include <linux/hashtable.h>
		#include <mount.h>
		static DEFINE_MUTEX(global_files_lock);
		static DEFINE_HASHTABLE(global_files_hashtable, 10);

		struct global_filetable_lookup_key {
		struct work_struct work;
		uintptr_t value;
		};

		void global_filetable_print_warning_once(void)
		{
		pr_err_once("\n**********************************************************\n");
		pr_err_once(" NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE \n");
		pr_err_once(" \n");
		pr_err_once(" VFS FILE TABLE DEBUG is enabled . \n");
		pr_err_once(" Allocating extra memory and slowing access to files \n");
		pr_err_once(" \n");
		pr_err_once(" This means that this is a DEBUG kernel and it is \n");
		pr_err_once(" unsafe for production use. \n");
		pr_err_once(" \n");
		pr_err_once(" If you see this message and you are not debugging \n");
		pr_err_once(" the kernel, report this immediately to your vendor! \n");
		pr_err_once(" \n");
		pr_err_once(" NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE \n");
		pr_err_once("**********************************************************\n");
		}

		void global_filetable_add(struct file *filp)
		{
		struct mount *mnt;

		if (filp->f_path.dentry->d_iname == NULL \|\|
		strlen(filp->f_path.dentry->d_iname) == 0)
		return;

		mnt = real_mount(filp->f_path.mnt);

		mutex_lock(&global_files_lock);
		hash_add(global_files_hashtable, &filp->f_hash, (uintptr_t)mnt);
		mutex_unlock(&global_files_lock);
		}

		void global_filetable_del(struct file *filp)
		{
		mutex_lock(&global_files_lock);
		hash_del(&filp->f_hash);
		mutex_unlock(&global_files_lock);
		}

		static void global_print_file(struct file filp, char path_buffer, int *count)
		{
		char *pathname;

		pathname = d_path(&filp->f_path, path_buffer, PAGE_SIZE);
		if (IS_ERR(pathname))
		pr_err("VFS: File %d Address : %pa partial filename: %s ref_count=%ld\n",
		++(*count), &filp, filp->f_path.dentry->d_iname,
		atomic_long_read(&filp->f_count));
		else
		pr_err("VFS: File %d Address : %pa full filepath: %s ref_count=%ld\n",
		++(*count), &filp, pathname,
		atomic_long_read(&filp->f_count));
		}

		static void global_filetable_print(uintptr_t lookup_mnt)
		{
		struct hlist_node *tmp;
		struct file *filp;
		struct mount *mnt;
		int index;
		int count = 0;
		char path_buffer = (char )__get_free_page(GFP_KERNEL);

		mutex_lock(&global_files_lock);
		pr_err("\n**********************************************************\n");
		pr_err(" NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE \n");

		pr_err("\n");
		pr_err("VFS: The following files hold a reference to the mount\n");
		pr_err("\n");
		hash_for_each_possible_safe(global_files_hashtable, filp, tmp, f_hash,
		lookup_mnt) {
		mnt = real_mount(filp->f_path.mnt);
		if ((uintptr_t)mnt == lookup_mnt)
		global_print_file(filp, path_buffer, &count);
		}
		pr_err("\n");
		pr_err("VFS: Found total of %d open files\n", count);
		pr_err("\n");

		count = 0;
		pr_err("\n");
		pr_err("VFS: The following files need to cleaned up\n");
		pr_err("\n");
		hash_for_each_safe(global_files_hashtable, index, tmp, filp, f_hash) {
		if (atomic_long_read(&filp->f_count) == 0)
		global_print_file(filp, path_buffer, &count);
		}

		pr_err("\n");
		pr_err("VFS: Found total of %d files awaiting clean-up\n", count);
		pr_err("\n");
		pr_err(" NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE \n");
		pr_err("\n**********************************************************\n");

		mutex_unlock(&global_files_lock);
		free_page((unsigned long)path_buffer);
		}

		static void global_filetable_print_work_fn(struct work_struct *work)
		{
		struct global_filetable_lookup_key *key;
		uintptr_t lookup_mnt;

		key = container_of(work, struct global_filetable_lookup_key, work);
		lookup_mnt = key->value;
		kfree(key);
		global_filetable_print(lookup_mnt);
		}

		void global_filetable_delayed_print(struct mount *mnt)
		{
		struct global_filetable_lookup_key *key;

		key = kzalloc(sizeof(*key), GFP_KERNEL);
		if (key == NULL)
		return;
		key->value = (uintptr_t)mnt;
		INIT_WORK(&key->work, global_filetable_print_work_fn);
		schedule_work(&key->work);
		}
		#endif /* CONFIG_FILE_TABLE_DEBUG */

		static void file_free_rcu(struct rcu_head *head)
		{
		struct file *f = container_of(head, struct file, f_u.fu_rcuhead);
		@@ -221,6 +356,7 @@ static void __fput(struct file *file)
		put_write_access(inode);
		__mnt_drop_write(mnt);
		}
		global_filetable_del(file);
		file->f_path.dentry = NULL;
		file->f_path.mnt = NULL;
		file->f_inode = NULL;
		@@ -320,6 +456,7 @@ void __init files_init(void)
		filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0,
		SLAB_HWCACHE_ALIGN \| SLAB_PANIC, NULL);
		percpu_counter_init(&nr_files, 0, GFP_KERNEL);
		global_filetable_print_warning_once();
		}

		/*

fs/internal.h

+26 −0

Original line number	Diff line number	Diff line
		@@ -186,3 +186,29 @@ loff_t iomap_apply(struct inode *inode, loff_t pos, loff_t length,

		/* direct-io.c: */
		int sb_init_dio_done_wq(struct super_block *sb);

		#ifdef CONFIG_FILE_TABLE_DEBUG
		void global_filetable_print_warning_once(void);
		void global_filetable_add(struct file *filp);
		void global_filetable_del(struct file *filp);
		void global_filetable_delayed_print(struct mount *mnt);

		#else /* i.e NOT CONFIG_FILE_TABLE_DEBUG */

		static inline void global_filetable_print_warning_once(void)
		{
		}

		static inline void global_filetable_add(struct file *filp)
		{
		}

		static inline void global_filetable_del(struct file *filp)
		{
		}

		static inline void global_filetable_delayed_print(struct mount *mnt)
		{
		}

		#endif /* CONFIG_FILE_TABLE_DEBUG */

fs/namei.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -3573,6 +3573,8 @@ static struct file path_openat(struct nameidata nd,
		error = -ESTALE;
		}
		file = ERR_PTR(error);
		} else {
		global_filetable_add(file);
		}
		return file;
		}

fs/namespace.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1668,6 +1668,8 @@ static int do_umount(struct mount *mnt, int flags)
		}
		unlock_mount_hash();
		namespace_unlock();
		if (retval == -EBUSY)
		global_filetable_delayed_print(mnt);
		return retval;
		}