root/fs/f2fs/trace.c

DEFINITIONS

1. __print_last_io
2. __file_type
3. f2fs_trace_pid
4. f2fs_trace_ios
5. f2fs_build_trace_ios
6. gang_lookup_pids
7. f2fs_destroy_trace_ios

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * f2fs IO tracer
   4  *
   5  * Copyright (c) 2014 Motorola Mobility
   6  * Copyright (c) 2014 Jaegeuk Kim <jaegeuk@kernel.org>
   7  */
   8 #include <linux/fs.h>
   9 #include <linux/f2fs_fs.h>
  10 #include <linux/sched.h>
  11 #include <linux/radix-tree.h>
  12 
  13 #include "f2fs.h"
  14 #include "trace.h"
  15 
  16 static RADIX_TREE(pids, GFP_ATOMIC);
  17 static spinlock_t pids_lock;
  18 static struct last_io_info last_io;
  19 
  20 static inline void __print_last_io(void)
  21 {
  22         if (!last_io.len)
  23                 return;
  24 
  25         trace_printk("%3x:%3x %4x %-16s %2x %5x %5x %12x %4x\n",
  26                         last_io.major, last_io.minor,
  27                         last_io.pid, "----------------",
  28                         last_io.type,
  29                         last_io.fio.op, last_io.fio.op_flags,
  30                         last_io.fio.new_blkaddr,
  31                         last_io.len);
  32         memset(&last_io, 0, sizeof(last_io));
  33 }
  34 
  35 static int __file_type(struct inode *inode, pid_t pid)
  36 {
  37         if (f2fs_is_atomic_file(inode))
  38                 return __ATOMIC_FILE;
  39         else if (f2fs_is_volatile_file(inode))
  40                 return __VOLATILE_FILE;
  41         else if (S_ISDIR(inode->i_mode))
  42                 return __DIR_FILE;
  43         else if (inode->i_ino == F2FS_NODE_INO(F2FS_I_SB(inode)))
  44                 return __NODE_FILE;
  45         else if (inode->i_ino == F2FS_META_INO(F2FS_I_SB(inode)))
  46                 return __META_FILE;
  47         else if (pid)
  48                 return __NORMAL_FILE;
  49         else
  50                 return __MISC_FILE;
  51 }
  52 
  53 void f2fs_trace_pid(struct page *page)
  54 {
  55         struct inode *inode = page->mapping->host;
  56         pid_t pid = task_pid_nr(current);
  57         void *p;
  58 
  59         set_page_private(page, (unsigned long)pid);
  60 
  61 retry:
  62         if (radix_tree_preload(GFP_NOFS))
  63                 return;
  64 
  65         spin_lock(&pids_lock);
  66         p = radix_tree_lookup(&pids, pid);
  67         if (p == current)
  68                 goto out;
  69         if (p)
  70                 radix_tree_delete(&pids, pid);
  71 
  72         if (radix_tree_insert(&pids, pid, current)) {
  73                 spin_unlock(&pids_lock);
  74                 radix_tree_preload_end();
  75                 cond_resched();
  76                 goto retry;
  77         }
  78 
  79         trace_printk("%3x:%3x %4x %-16s\n",
  80                         MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev),
  81                         pid, current->comm);
  82 out:
  83         spin_unlock(&pids_lock);
  84         radix_tree_preload_end();
  85 }
  86 
  87 void f2fs_trace_ios(struct f2fs_io_info *fio, int flush)
  88 {
  89         struct inode *inode;
  90         pid_t pid;
  91         int major, minor;
  92 
  93         if (flush) {
  94                 __print_last_io();
  95                 return;
  96         }
  97 
  98         inode = fio->page->mapping->host;
  99         pid = page_private(fio->page);
 100 
 101         major = MAJOR(inode->i_sb->s_dev);
 102         minor = MINOR(inode->i_sb->s_dev);
 103 
 104         if (last_io.major == major && last_io.minor == minor &&
 105                         last_io.pid == pid &&
 106                         last_io.type == __file_type(inode, pid) &&
 107                         last_io.fio.op == fio->op &&
 108                         last_io.fio.op_flags == fio->op_flags &&
 109                         last_io.fio.new_blkaddr + last_io.len ==
 110                                                         fio->new_blkaddr) {
 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 == max_items)
 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 }