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 struct mutex 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 %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
  38 static 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
  56 void 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         set_page_private(page, (unsigned long)pid);
  63
  64         if (radix_tree_preload(GFP_NOFS))
  65                 return;
  66
  67         mutex_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);
  79 out:
  80         mutex_unlock(&pids_lock);
  81         radix_tree_preload_end();
  82 }
  83
  84 void 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
 123 void f2fs_build_trace_ios(void)
 124 {
 125         mutex_init(&pids_lock);
 126 }
 127
 128 #define PIDVEC_SIZE     128
 129 static 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 == max_items)
 142                         break;
 143         }
 144         return ret;
 145 }
 146
 147 void f2fs_destroy_trace_ios(void)
 148 {
 149         pid_t pid[PIDVEC_SIZE];
 150         pid_t next_pid = 0;
 151         unsigned int found;
 152
 153         mutex_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         mutex_unlock(&pids_lock);
 162 }