1/*
  2 * f2fs IO tracer
  3 *
  4 * Copyright (c) 2014 Motorola Mobility
  5 * Copyright (c) 2014 Jaegeuk Kim <jaegeuk@kernel.org>
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of the GNU General Public License version 2 as
  9 * published by the Free Software Foundation.
 10 */
 11#include <linux/fs.h>
 12#include <linux/f2fs_fs.h>
 13#include <linux/sched.h>
 14#include <linux/radix-tree.h>
 15
 16#include "f2fs.h"
 17#include "trace.h"
 18
 19static RADIX_TREE(pids, GFP_ATOMIC);
 20static spinlock_t pids_lock;
 21static struct last_io_info last_io;
 22
 23static inline void __print_last_io(void)
 24{
 25	if (!last_io.len)
 26		return;
 27
 28	trace_printk("%3x:%3x %4x %-16s %2x %5x %5x %12x %4x\n",
 29			last_io.major, last_io.minor,
 30			last_io.pid, "----------------",
 31			last_io.type,
 32			last_io.fio.op, last_io.fio.op_flags,
 33			last_io.fio.new_blkaddr,
 34			last_io.len);
 35	memset(&last_io, 0, sizeof(last_io));
 36}
 37
 38static int __file_type(struct inode *inode, pid_t pid)
 39{
 40	if (f2fs_is_atomic_file(inode))
 41		return __ATOMIC_FILE;
 42	else if (f2fs_is_volatile_file(inode))
 43		return __VOLATILE_FILE;
 44	else if (S_ISDIR(inode->i_mode))
 45		return __DIR_FILE;
 46	else if (inode->i_ino == F2FS_NODE_INO(F2FS_I_SB(inode)))
 47		return __NODE_FILE;
 48	else if (inode->i_ino == F2FS_META_INO(F2FS_I_SB(inode)))
 49		return __META_FILE;
 50	else if (pid)
 51		return __NORMAL_FILE;
 52	else
 53		return __MISC_FILE;
 54}
 55
 56void f2fs_trace_pid(struct page *page)
 57{
 58	struct inode *inode = page->mapping->host;
 59	pid_t pid = task_pid_nr(current);
 60	void *p;
 61
 62	page->private = pid;
 63
 64	if (radix_tree_preload(GFP_NOFS))
 65		return;
 66
 67	spin_lock(&pids_lock);
 68	p = radix_tree_lookup(&pids, pid);
 69	if (p == current)
 70		goto out;
 71	if (p)
 72		radix_tree_delete(&pids, pid);
 73
 74	f2fs_radix_tree_insert(&pids, pid, current);
 75
 76	trace_printk("%3x:%3x %4x %-16s\n",
 77			MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev),
 78			pid, current->comm);
 79out:
 80	spin_unlock(&pids_lock);
 81	radix_tree_preload_end();
 82}
 83
 84void f2fs_trace_ios(struct f2fs_io_info *fio, int flush)
 85{
 86	struct inode *inode;
 87	pid_t pid;
 88	int major, minor;
 89
 90	if (flush) {
 91		__print_last_io();
 92		return;
 93	}
 94
 95	inode = fio->page->mapping->host;
 96	pid = page_private(fio->page);
 97
 98	major = MAJOR(inode->i_sb->s_dev);
 99	minor = MINOR(inode->i_sb->s_dev);
100
101	if (last_io.major == major && last_io.minor == minor &&
102			last_io.pid == pid &&
103			last_io.type == __file_type(inode, pid) &&
104			last_io.fio.op == fio->op &&
105			last_io.fio.op_flags == fio->op_flags &&
106			last_io.fio.new_blkaddr + last_io.len ==
107							fio->new_blkaddr) {
108		last_io.len++;
109		return;
110	}
111
112	__print_last_io();
113
114	last_io.major = major;
115	last_io.minor = minor;
116	last_io.pid = pid;
117	last_io.type = __file_type(inode, pid);
118	last_io.fio = *fio;
119	last_io.len = 1;
120	return;
121}
122
123void f2fs_build_trace_ios(void)
124{
125	spin_lock_init(&pids_lock);
126}
127
128#define PIDVEC_SIZE	128
129static unsigned int gang_lookup_pids(pid_t *results, unsigned long first_index,
130							unsigned int max_items)
131{
132	struct radix_tree_iter iter;
133	void **slot;
134	unsigned int ret = 0;
135
136	if (unlikely(!max_items))
137		return 0;
138
139	radix_tree_for_each_slot(slot, &pids, &iter, first_index) {
140		results[ret] = iter.index;
141		if (++ret == PIDVEC_SIZE)
142			break;
143	}
144	return ret;
145}
146
147void f2fs_destroy_trace_ios(void)
148{
149	pid_t pid[PIDVEC_SIZE];
150	pid_t next_pid = 0;
151	unsigned int found;
152
153	spin_lock(&pids_lock);
154	while ((found = gang_lookup_pids(pid, next_pid, PIDVEC_SIZE))) {
155		unsigned idx;
156
157		next_pid = pid[found - 1] + 1;
158		for (idx = 0; idx < found; idx++)
159			radix_tree_delete(&pids, pid[idx]);
160	}
161	spin_unlock(&pids_lock);
162}