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 %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         page->private = pid;
  63
  64 retry:
  65         if (radix_tree_preload(GFP_NOFS))
  66                 return;
  67
  68         spin_lock(&pids_lock);
  69         p = radix_tree_lookup(&pids, pid);
  70         if (p == current)
  71                 goto out;
  72         if (p)
  73                 radix_tree_delete(&pids, pid);
  74
  75         if (radix_tree_insert(&pids, pid, current)) {
  76                 spin_unlock(&pids_lock);
  77                 radix_tree_preload_end();
  78                 cond_resched();
  79                 goto retry;
  80         }
  81
  82         trace_printk("%3x:%3x %4x %-16s\n",
  83                         MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev),
  84                         pid, current->comm);
  85 out:
  86         spin_unlock(&pids_lock);
  87         radix_tree_preload_end();
  88 }
  89
  90 void f2fs_trace_ios(struct f2fs_io_info *fio, int flush)
  91 {
  92         struct inode *inode;
  93         pid_t pid;
  94         int major, minor;
  95
  96         if (flush) {
  97                 __print_last_io();
  98                 return;
  99         }
 100
 101         inode = fio->page->mapping->host;
 102         pid = page_private(fio->page);
 103
 104         major = MAJOR(inode->i_sb->s_dev);
 105         minor = MINOR(inode->i_sb->s_dev);
 106
 107         if (last_io.major == major && last_io.minor == minor &&
 108                         last_io.pid == pid &&
 109                         last_io.type == __file_type(inode, pid) &&
 110                         last_io.fio.op == fio->op &&
 111                         last_io.fio.op_flags == fio->op_flags &&
 112                         last_io.fio.new_blkaddr + last_io.len ==
 113                                                         fio->new_blkaddr) {
 114                 last_io.len++;
 115                 return;
 116         }
 117
 118         __print_last_io();
 119
 120         last_io.major = major;
 121         last_io.minor = minor;
 122         last_io.pid = pid;
 123         last_io.type = __file_type(inode, pid);
 124         last_io.fio = *fio;
 125         last_io.len = 1;
 126         return;
 127 }
 128
 129 void f2fs_build_trace_ios(void)
 130 {
 131         spin_lock_init(&pids_lock);
 132 }
 133
 134 #define PIDVEC_SIZE     128
 135 static unsigned int gang_lookup_pids(pid_t *results, unsigned long first_index,
 136                                                         unsigned int max_items)
 137 {
 138         struct radix_tree_iter iter;
 139         void **slot;
 140         unsigned int ret = 0;
 141
 142         if (unlikely(!max_items))
 143                 return 0;
 144
 145         radix_tree_for_each_slot(slot, &pids, &iter, first_index) {
 146                 results[ret] = iter.index;
 147                 if (++ret == PIDVEC_SIZE)
 148                         break;
 149         }
 150         return ret;
 151 }
 152
 153 void f2fs_destroy_trace_ios(void)
 154 {
 155         pid_t pid[PIDVEC_SIZE];
 156         pid_t next_pid = 0;
 157         unsigned int found;
 158
 159         spin_lock(&pids_lock);
 160         while ((found = gang_lookup_pids(pid, next_pid, PIDVEC_SIZE))) {
 161                 unsigned idx;
 162
 163                 next_pid = pid[found - 1] + 1;
 164                 for (idx = 0; idx < found; idx++)
 165                         radix_tree_delete(&pids, pid[idx]);
 166         }
 167         spin_unlock(&pids_lock);
 168 }