diff options
Diffstat (limited to 'fs/file_table.c')
| -rw-r--r-- | fs/file_table.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/fs/file_table.c b/fs/file_table.c index ad17e05ebf95..b4baa0de4988 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -41,6 +41,141 @@ 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_TEMPORARY); + + 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); @@ -219,6 +354,7 @@ 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; @@ -314,6 +450,7 @@ 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(); } /* |