fs/f2fs/trace.c

   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
  19 static RADIX_TREE(pids, GFP_ATOMIC);
  20 static spinlock_t pids_lock;
  21 static struct last_io_info last_io;
  22
  23 static inline void __print_last_io(void)
  24 {
  25         if (!last_io.len)
  26                 return;
  27
  28         trace_printk("%3x:%3x %4x %-16s %2x %5x %12x %4x\n",
  29                         last_io.major, last_io.minor,
  30                         last_io.pid, "----------------",
  31                         last_io.type,
  32                         last_io.fio.rw, last_io.fio.blk_addr,
  33                         last_io.len);
  34         memset(&last_io, 0, sizeof(last_io));
  35 }
  36
  37 static int __file_type(struct inode *inode, pid_t pid)
  38 {
  39         if (f2fs_is_atomic_file(inode))
  40                 return __ATOMIC_FILE;
  41         else if (f2fs_is_volatile_file(inode))
  42                 return __VOLATILE_FILE;
  43         else if (S_ISDIR(inode->i_mode))
  44                 return __DIR_FILE;
  45         else if (inode->i_ino == F2FS_NODE_INO(F2FS_I_SB(inode)))
  46                 return __NODE_FILE;
  47         else if (inode->i_ino == F2FS_META_INO(F2FS_I_SB(inode)))
  48                 return __META_FILE;
  49         else if (pid)
  50                 return __NORMAL_FILE;
  51         else
  52                 return __MISC_FILE;
  53 }
  54
  55 void f2fs_trace_pid(struct page *page)
  56 {
  57         struct inode *inode = page->mapping->host;
  58         pid_t pid = task_pid_nr(current);
  59         void *p;
  60
  61         page->private = pid;
  62
  63 retry:
  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         if (radix_tree_insert(&pids, pid, current)) {
  75                 spin_unlock(&pids_lock);
  76                 radix_tree_preload_end();
  77                 cond_resched();
  78                 goto retry;
  79         }
  80
  81         trace_printk("%3x:%3x %4x %-16s\n",
  82                         MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev),
  83                         pid, current->comm);
  84 out:
  85         spin_unlock(&pids_lock);
  86         radix_tree_preload_end();
  87 }
  88
  89 void f2fs_trace_ios(struct f2fs_io_info *fio, int flush)
  90 {
  91         struct inode *inode;
  92         pid_t pid;
  93         int major, minor;
  94
  95         if (flush) {
  96                 __print_last_io();
  97                 return;
  98         }
  99
 100         inode = fio->page->mapping->host;
 101         pid = page_private(fio->page);
 102
 103         major = MAJOR(inode->i_sb->s_dev);
 104         minor = MINOR(inode->i_sb->s_dev);
 105
 106         if (last_io.major == major && last_io.minor == minor &&
 107                         last_io.pid == pid &&
 108                         last_io.type == __file_type(inode, pid) &&
 109                         last_io.fio.rw == fio->rw &&
 110                         last_io.fio.blk_addr + last_io.len == fio->blk_addr) {
 111                 last_io.len++;
 112                 return;
 113         }
 114
 115         __print_last_io();
 116
 117         last_io.major = major;
 118         last_io.minor = minor;
 119         last_io.pid = pid;
 120         last_io.type = __file_type(inode, pid);
 121         last_io.fio = *fio;
 122         last_io.len = 1;
 123         return;
 124 }
 125
 126 void f2fs_build_trace_ios(void)
 127 {
 128         spin_lock_init(&pids_lock);
 129 }
 130
 131 #define PIDVEC_SIZE     128
 132 static unsigned int gang_lookup_pids(pid_t *results, unsigned long first_index,
 133                                                         unsigned int max_items)
 134 {
 135         struct radix_tree_iter iter;
 136         void **slot;
 137         unsigned int ret = 0;
 138
 139         if (unlikely(!max_items))
 140                 return 0;
 141
 142         radix_tree_for_each_slot(slot, &pids, &iter, first_index) {
 143                 results[ret] = iter.index;
 144                 if (++ret == PIDVEC_SIZE)
 145                         break;
 146         }
 147         return ret;
 148 }
 149
 150 void f2fs_destroy_trace_ios(void)
 151 {
 152         pid_t pid[PIDVEC_SIZE];
 153         pid_t next_pid = 0;
 154         unsigned int found;
 155
 156         spin_lock(&pids_lock);
 157         while ((found = gang_lookup_pids(pid, next_pid, PIDVEC_SIZE))) {
 158                 unsigned idx;
 159
 160                 next_pid = pid[found - 1] + 1;
 161                 for (idx = 0; idx < found; idx++)
 162                         radix_tree_delete(&pids, pid[idx]);
 163         }
 164         spin_unlock(&pids_lock);
 165 }