1 files changed, 159 insertions, 0 deletions

diff --git a/fs/f2fs/trace.c b/fs/f2fs/trace.c
new file mode 100644
index 000000000000..875aa8179bc1
--- /dev/null
+++ b/fs/f2fs/trace.c
@@ -0,0 +1,159 @@
+/*
+ * f2fs IO tracer
+ *
+ * Copyright (c) 2014 Motorola Mobility
+ * Copyright (c) 2014 Jaegeuk Kim <jaegeuk@kernel.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/fs.h>
+#include <linux/f2fs_fs.h>
+#include <linux/sched.h>
+#include <linux/radix-tree.h>
+
+#include "f2fs.h"
+#include "trace.h"
+
+static RADIX_TREE(pids, GFP_ATOMIC);
+static spinlock_t pids_lock;
+static struct last_io_info last_io;
+
+static inline void __print_last_io(void)
+{
+        if (!last_io.len)
+                return;
+
+        trace_printk("%3x:%3x %4x %-16s %2x %5x %12x %4x\n",
+                        last_io.major, last_io.minor,
+                        last_io.pid, "----------------",
+                        last_io.type,
+                        last_io.fio.rw, last_io.fio.blk_addr,
+                        last_io.len);
+        memset(&last_io, 0, sizeof(last_io));
+}
+
+static int __file_type(struct inode *inode, pid_t pid)
+{
+        if (f2fs_is_atomic_file(inode))
+                return __ATOMIC_FILE;
+        else if (f2fs_is_volatile_file(inode))
+                return __VOLATILE_FILE;
+        else if (S_ISDIR(inode->i_mode))
+                return __DIR_FILE;
+        else if (inode->i_ino == F2FS_NODE_INO(F2FS_I_SB(inode)))
+                return __NODE_FILE;
+        else if (inode->i_ino == F2FS_META_INO(F2FS_I_SB(inode)))
+                return __META_FILE;
+        else if (pid)
+                return __NORMAL_FILE;
+        else
+                return __MISC_FILE;
+}
+
+void f2fs_trace_pid(struct page *page)
+{
+        struct inode *inode = page->mapping->host;
+        pid_t pid = task_pid_nr(current);
+        void *p;
+
+        page->private = pid;
+
+        if (radix_tree_preload(GFP_NOFS))
+                return;
+
+        spin_lock(&pids_lock);
+        p = radix_tree_lookup(&pids, pid);
+        if (p == current)
+                goto out;
+        if (p)
+                radix_tree_delete(&pids, pid);
+
+        f2fs_radix_tree_insert(&pids, pid, current);
+
+        trace_printk("%3x:%3x %4x %-16s\n",
+                        MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev),
+                        pid, current->comm);
+out:
+        spin_unlock(&pids_lock);
+        radix_tree_preload_end();
+}
+
+void f2fs_trace_ios(struct page *page, struct f2fs_io_info *fio, int flush)
+{
+        struct inode *inode;
+        pid_t pid;
+        int major, minor;
+
+        if (flush) {
+                __print_last_io();
+                return;
+        }
+
+        inode = page->mapping->host;
+        pid = page_private(page);
+
+        major = MAJOR(inode->i_sb->s_dev);
+        minor = MINOR(inode->i_sb->s_dev);
+
+        if (last_io.major == major && last_io.minor == minor &&
+                        last_io.pid == pid &&
+                        last_io.type == __file_type(inode, pid) &&
+                        last_io.fio.rw == fio->rw &&
+                        last_io.fio.blk_addr + last_io.len == fio->blk_addr) {
+                last_io.len++;
+                return;
+        }
+
+        __print_last_io();
+
+        last_io.major = major;
+        last_io.minor = minor;
+        last_io.pid = pid;
+        last_io.type = __file_type(inode, pid);
+        last_io.fio = *fio;
+        last_io.len = 1;
+        return;
+}
+
+void f2fs_build_trace_ios(void)
+{
+        spin_lock_init(&pids_lock);
+}
+
+#define PIDVEC_SIZE     128
+static unsigned int gang_lookup_pids(pid_t *results, unsigned long first_index,
+                                                        unsigned int max_items)
+{
+        struct radix_tree_iter iter;
+        void **slot;
+        unsigned int ret = 0;
+
+        if (unlikely(!max_items))
+                return 0;
+
+        radix_tree_for_each_slot(slot, &pids, &iter, first_index) {
+                results[ret] = iter.index;
+                if (++ret == PIDVEC_SIZE)
+                        break;
+        }
+        return ret;
+}
+
+void f2fs_destroy_trace_ios(void)
+{
+        pid_t pid[PIDVEC_SIZE];
+        pid_t next_pid = 0;
+        unsigned int found;
+
+        spin_lock(&pids_lock);
+        while ((found = gang_lookup_pids(pid, next_pid, PIDVEC_SIZE))) {
+                unsigned idx;
+
+                next_pid = pid[found - 1] + 1;
+                for (idx = 0; idx < found; idx++)
+                        radix_tree_delete(&pids, pid[idx]);
+        }
+        spin_unlock(&pids_lock);
+}