From: Zhi Yong Wu <wu...@linux.vnet.ibm.com>
Add a /sys/kernel/debug/hot_track/<device_name>/ directory for each
volume that contains two files. The first, `inode_data', contains the
heat information for inodes that have been brought into the hot data map
structures. The second, `range_data', contains similar information for
subfile ranges.
Signed-off-by: Zhi Yong Wu <wu...@linux.vnet.ibm.com>
---
fs/hot_tracking.c | 462 +++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/hot_tracking.h | 43 +++++
2 files changed, 505 insertions(+), 0 deletions(-)
diff --git a/fs/hot_tracking.c b/fs/hot_tracking.c
index fcde55e..60e93e6 100644
--- a/fs/hot_tracking.c
+++ b/fs/hot_tracking.c
@@ -20,6 +20,8 @@
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/types.h>
+#include <linux/debugfs.h>
+#include <linux/vmalloc.h>
#include <linux/limits.h>
#include "hot_tracking.h"
@@ -29,6 +31,13 @@ struct hot_info *global_hot_tracking_info;
static struct kmem_cache *hot_inode_item_cachep;
static struct kmem_cache *hot_range_item_cachep;
+/* list to keep track of each mounted volumes debugfs_vol_data */
+static struct list_head hot_debugfs_vol_data_list;
+/* lock for debugfs_vol_data_list */
+static spinlock_t hot_debugfs_data_list_lock;
+/* pointer to top level debugfs dentry */
+static struct dentry *hot_debugfs_root_dentry;
+
/*
* Initialize the inode tree. Should be called for each new inode
* access or other user of the hot_inode interface.
@@ -706,6 +715,451 @@ static void hot_wq_exit(struct workqueue_struct *wq)
destroy_workqueue(wq);
}
+static int hot_debugfs_copy(struct debugfs_vol_data *data, char *msg, int len)
+{
+ struct lstring *debugfs_log = data->debugfs_log;
+ uint new_log_alloc_size;
+ char *new_log;
+ static char err_msg[] = "No more memory!\n";
+
+ if (len >= data->log_alloc_size - debugfs_log->len) {
+ /*
+ * Not enough room in the log buffer for the new message.
+ * Allocate a bigger buffer.
+ */
+ new_log_alloc_size = data->log_alloc_size + LOG_PAGE_SIZE;
+ new_log = vmalloc(new_log_alloc_size);
+
+ if (new_log) {
+ memcpy(new_log, debugfs_log->str, debugfs_log->len);
+ memset(new_log + debugfs_log->len, 0,
+ new_log_alloc_size - debugfs_log->len);
+ vfree(debugfs_log->str);
+ debugfs_log->str = new_log;
+ data->log_alloc_size = new_log_alloc_size;
+ } else {
+ WARN_ON(1);
+ if (data->log_alloc_size - debugfs_log->len) {
+ strlcpy(debugfs_log->str +
+ debugfs_log->len,
+ err_msg,
+ data->log_alloc_size - debugfs_log->len);
+ debugfs_log->len +=
+ min((typeof(debugfs_log->len))
+ sizeof(err_msg),
+ ((typeof(debugfs_log->len))
+ data->log_alloc_size - debugfs_log->len));
+ }
+ return 0;
+ }
+ }
+
+ memcpy(debugfs_log->str + debugfs_log->len, data->log_work_buff, len);
+ debugfs_log->len += (unsigned long) len;
+
+ return len;
+}
+
+/* Returns the number of bytes written to the log. */
+static int hot_debugfs_log(struct debugfs_vol_data *data, const char *fmt, ...)
+{
+ struct lstring *debugfs_log = data->debugfs_log;
+ va_list args;
+ int len;
+ static char trunc_msg[] =
+ "The next message has been truncated.\n";
+
+ if (debugfs_log->str == NULL)
+ return -1;
+
+ spin_lock(&data->log_lock);
+
+ va_start(args, fmt);
+ len = vsnprintf(data->log_work_buff,
+ sizeof(data->log_work_buff), fmt, args);
+ va_end(args);
+
+ if (len >= sizeof(data->log_work_buff)) {
+ hot_debugfs_copy(data, trunc_msg, sizeof(trunc_msg));
+ }
+
+ len = hot_debugfs_copy(data, data->log_work_buff, len);
+ spin_unlock(&data->log_lock);
+
+ return len;
+}
+
+/* initialize a log corresponding to a fs volume */
+static int hot_debugfs_log_init(struct debugfs_vol_data *data)
+{
+ int err = 0;
+ struct lstring *debugfs_log = data->debugfs_log;
+
+ spin_lock(&data->log_lock);
+ debugfs_log->str = vmalloc(INIT_LOG_ALLOC_SIZE);
+ if (debugfs_log->str) {
+ memset(debugfs_log->str, 0, INIT_LOG_ALLOC_SIZE);
+ data->log_alloc_size = INIT_LOG_ALLOC_SIZE;
+ } else {
+ err = -ENOMEM;
+ }
+ spin_unlock(&data->log_lock);
+
+ return err;
+}
+
+/* free a log corresponding to a fs volume */
+static void hot_debugfs_log_exit(struct debugfs_vol_data *data)
+{
+ struct lstring *debugfs_log = data->debugfs_log;
+
+ spin_lock(&data->log_lock);
+ vfree(debugfs_log->str);
+ debugfs_log->str = NULL;
+ debugfs_log->len = 0;
+ spin_unlock(&data->log_lock);
+}
+
+/* debugfs open file override from fops table */
+static int __hot_debugfs_open(struct inode *inode, struct file *file)
+{
+ if (inode->i_private)
+ file->private_data = inode->i_private;
+
+ return 0;
+}
+
+static void __hot_debugfs_print_range_freq_data(
+ struct hot_inode_item *he,
+ struct hot_range_item *hr,
+ struct debugfs_vol_data *data,
+ struct hot_info *root)
+{
+ struct hot_freq_data *freq_data;
+
+ freq_data = &hr->hot_range.hot_freq_data;
+
+ /* Always lock hot_inode_item first */
+ spin_lock(&he->hot_inode.lock);
+ spin_lock(&hr->hot_range.lock);
+ hot_debugfs_log(data, "inode #%lu, range start " \
+ "%llu (range len %llu) reads %u, writes %u, "
+ "avg read time %llu, avg write time %llu, temp %u\n",
+ he->i_ino,
+ hr->start,
+ hr->len,
+ freq_data->nr_reads,
+ freq_data->nr_writes,
+ freq_data->avg_delta_reads,
+ freq_data->avg_delta_writes,
+ freq_data->last_temperature);
+ spin_unlock(&hr->hot_range.lock);
+ spin_unlock(&he->hot_inode.lock);
+}
+
+/*
+ * take the inode, find ranges associated with inode
+ * and print each range data struct
+ */
+static void __hot_debugfs_walk_range_tree(struct hot_inode_item *he,
+ struct debugfs_vol_data *data,
+ struct hot_info *root)
+{
+ struct hot_range_item *hr_nodes[8];
+ u32 start = 0;
+ int i, n;
+
+ /* Walk the hot_range_tree for inode */
+ while (1) {
+ spin_lock(&he->lock);
+ n = radix_tree_gang_lookup(&he->hot_range_tree,
+ (void **)hr_nodes, start,
+ ARRAY_SIZE(hr_nodes));
+ if (!n) {
+ spin_unlock(&he->lock);
+ break;
+ }
+
+ start = hr_nodes[n - 1]->start + 1;
+ for (i = 0; i < n; i++) {
+ kref_get(&hr_nodes[i]->hot_range.refs);
+ __hot_debugfs_print_range_freq_data(he,
+ hr_nodes[i], data, root);
+ hot_range_item_put(hr_nodes[i]);
+ }
+ spin_unlock(&he->lock);
+ }
+}
+
+/* Print frequency data for each freq data to log */
+static void __hot_debugfs_print_inode_freq_data(
+ struct hot_inode_item *he,
+ struct debugfs_vol_data *data,
+ struct hot_info *root)
+{
+ struct hot_freq_data *freq_data = &he->hot_inode.hot_freq_data;
+
+ spin_lock(&he->hot_inode.lock);
+ hot_debugfs_log(data, "inode #%lu, reads %u, writes %u, " \
+ "avg read time %llu, avg write time %llu, temp %u\n",
+ he->i_ino,
+ freq_data->nr_reads,
+ freq_data->nr_writes,
+ freq_data->avg_delta_reads,
+ freq_data->avg_delta_writes,
+ freq_data->last_temperature);
+ spin_unlock(&he->hot_inode.lock);
+}
+
+/* debugfs common read file override from fops table */
+static ssize_t __hot_debugfs_comm_read(struct file *file, char __user *user,
+ size_t count, loff_t *ppos,
+ hot_debugfs_walk_t private_walk)
+{
+ int err = 0;
+ struct hot_info *root;
+ struct debugfs_vol_data *data;
+ struct lstring *debugfs_log;
+ struct hot_inode_item *hi_nodes[8];
+ u64 ino = 0;
+ int i, n;
+
+ data = (struct debugfs_vol_data *) file->private_data;
+ root = global_hot_tracking_info;
+
+ if (!data->debugfs_log) {
+ /* initialize debugfs log corresponding to this volume */
+ debugfs_log = kmalloc(sizeof(struct lstring),
+ GFP_KERNEL | GFP_NOFS);
+ debugfs_log->str = NULL,
+ debugfs_log->len = 0;
+ data->debugfs_log = debugfs_log;
+ hot_debugfs_log_init(data);
+ }
+
+ if ((unsigned long) *ppos > 0) {
+ /* caller is continuing a previous read, don't walk tree */
+ if ((unsigned long) *ppos >= data->debugfs_log->len)
+ goto clean_up;
+
+ goto print_to_user;
+ }
+
+ /* walk the inode tree */
+ while (1) {
+ spin_lock(&root->lock);
+ n = radix_tree_gang_lookup(&root->hot_inode_tree,
+ (void **)hi_nodes, ino,
+ ARRAY_SIZE(hi_nodes));
+ if (!n) {
+ spin_unlock(&root->lock);
+ break;
+ }
+
+ ino = hi_nodes[n - 1]->i_ino + 1;
+ for (i = 0; i < n; i++) {
+ kref_get(&hi_nodes[i]->hot_inode.refs);
+ /* walk ranges, print data to debugfs log */
+ private_walk(hi_nodes[i], data, root);
+ hot_inode_item_put(hi_nodes[i]);
+ }
+ spin_unlock(&root->lock);
+ }
+
+print_to_user:
+ if (data->debugfs_log->len) {
+ err = simple_read_from_buffer(user, count, ppos,
+ data->debugfs_log->str,
+ data->debugfs_log->len);
+ }
+
+ return err;
+
+clean_up:
+ /* reader has finished the file, clean up */
+ hot_debugfs_log_exit(data);
+ kfree(data->debugfs_log);
+ data->debugfs_log = NULL;
+
+ return 0;
+}
+
+/* debugfs read file override from fops table */
+static ssize_t __hot_debugfs_range_read(struct file *file, char __user *user,
+ size_t count, loff_t *ppos)
+{
+ return __hot_debugfs_comm_read(file, user,count, ppos,
+ __hot_debugfs_walk_range_tree);
+}
+
+/* debugfs read file override from fops table */
+static ssize_t __hot_debugfs_inode_read(struct file *file, char __user *user,
+ size_t count, loff_t *ppos)
+{
+ return __hot_debugfs_comm_read(file, user,count, ppos,
+ __hot_debugfs_print_inode_freq_data);
+
+}
+
+/* fops to override for printing range data */
+static const struct file_operations hot_debugfs_range_fops = {
+ .read = __hot_debugfs_range_read,
+ .open = __hot_debugfs_open,
+};
+
+/* fops to override for printing inode data */
+static const struct file_operations hot_debugfs_inode_fops = {
+ .read = __hot_debugfs_inode_read,
+ .open = __hot_debugfs_open,
+};
+
+/*
+ * on each volume mount, initialize the debugfs dentries and associated
+ * structures (debugfs_vol_data and debugfs_log)
+ */
+static int hot_debugfs_volume_init(struct super_block *sb)
+{
+ struct dentry *debugfs_volume_entry = NULL;
+ struct dentry *debugfs_range_entry = NULL;
+ struct dentry *debugfs_inode_entry = NULL;
+ struct debugfs_vol_data *range_data = NULL;
+ struct debugfs_vol_data *inode_data = NULL;
+
+ if (!hot_debugfs_root_dentry)
+ goto debugfs_error;
+
+ /* create debugfs folder for this volume by mounted dev name */
+ debugfs_volume_entry = debugfs_create_dir(sb->s_id,
hot_debugfs_root_dentry);
+
+ if (!debugfs_volume_entry)
+ goto debugfs_error;
+
+ /* malloc and initialize debugfs_vol_data for range_data */
+ range_data = kmalloc(sizeof(struct debugfs_vol_data),
+ GFP_KERNEL | GFP_NOFS);
+ memset(range_data, 0, sizeof(struct debugfs_vol_data));
+ range_data->debugfs_log = NULL;
+ range_data->sb = sb;
+ spin_lock_init(&range_data->log_lock);
+ range_data->log_alloc_size = 0;
+
+ /* malloc and initialize debugfs_vol_data for inode_data */
+ inode_data = kmalloc(sizeof(struct debugfs_vol_data),
+ GFP_KERNEL | GFP_NOFS);
+ memset(inode_data, 0, sizeof(struct debugfs_vol_data));
+ inode_data->debugfs_log = NULL;
+ inode_data->sb = sb;
+ spin_lock_init(&inode_data->log_lock);
+ inode_data->log_alloc_size = 0;
+
+ /*
+ * add debugfs_vol_data for inode data and range data for
+ * volume to list
+ */
+ range_data->de = debugfs_volume_entry;
+ inode_data->de = debugfs_volume_entry;
+ spin_lock(&hot_debugfs_data_list_lock);
+ list_add(&range_data->node, &hot_debugfs_vol_data_list);
+ list_add(&inode_data->node, &hot_debugfs_vol_data_list);
+ spin_unlock(&hot_debugfs_data_list_lock);
+
+ /* create debugfs range_data file */
+ debugfs_range_entry = debugfs_create_file("range_data",
+ S_IFREG | S_IRUSR | S_IWUSR | S_IRUGO,
+ debugfs_volume_entry,
+ (void *) range_data,
+ &hot_debugfs_range_fops);
+ if (!debugfs_range_entry)
+ goto debugfs_error;
+
+ /* create debugfs inode_data file */
+ debugfs_inode_entry = debugfs_create_file("inode_data",
+ S_IFREG | S_IRUSR | S_IWUSR | S_IRUGO,
+ debugfs_volume_entry,
+ (void *) inode_data,
+ &hot_debugfs_inode_fops);
+
+ if (!debugfs_inode_entry)
+ goto debugfs_error;
+
+ return 0;
+
+debugfs_error:
+ kfree(range_data);
+ kfree(inode_data);
+
+ return -EIO;
+}
+
+/*
+ * find volume mounted (match by superblock) and remove
+ * debugfs dentry
+ */
+static void hot_debugfs_volume_exit(struct super_block *sb)
+{
+ struct list_head *head;
+ struct list_head *pos;
+ struct debugfs_vol_data *data;
+
+ spin_lock(&hot_debugfs_data_list_lock);
+ head = &hot_debugfs_vol_data_list;
+ /* must clean up memory assicatied with superblock */
+ list_for_each(pos, head)
+ {
+ data = list_entry(pos, struct debugfs_vol_data, node);
+ if (data->sb == sb) {
+ list_del(pos);
+ debugfs_remove_recursive(data->de);
+ kfree(data);
+ data = NULL;
+ }
+ }
+ spin_unlock(&hot_debugfs_data_list_lock);
+}
+
+/* initialize debugfs */
+static int hot_debugfs_init(struct super_block *sb)
+{
+ hot_debugfs_root_dentry = debugfs_create_dir(DEBUGFS_ROOT_NAME, NULL);
+ /*init list of debugfs data list */
+ INIT_LIST_HEAD(&hot_debugfs_vol_data_list);
+ /*init lock to list of debugfs data list */
+ spin_lock_init(&hot_debugfs_data_list_lock);
+ if (!hot_debugfs_root_dentry)
+ goto debugfs_error;
+
+ hot_debugfs_volume_init(sb);
+
+ return 0;
+
+debugfs_error:
+ return -EIO;
+}
+
+/* clean up memory and remove dentries for debugsfs */
+static void hot_debugfs_exit(struct super_block *sb)
+{
+ /* first iterate through debugfs_vol_data_list and free memory */
+ struct list_head *head;
+ struct list_head *pos;
+ struct list_head *cur;
+ struct debugfs_vol_data *data;
+
+ hot_debugfs_volume_exit(sb);
+
+ spin_lock(&hot_debugfs_data_list_lock);
+ head = &hot_debugfs_vol_data_list;
+ list_for_each_safe(pos, cur, head) {
+ data = list_entry(pos, struct debugfs_vol_data, node);
+ if (data && pos != head)
+ kfree(data);
+ }
+ spin_unlock(&hot_debugfs_data_list_lock);
+
+ /* remove all debugfs entries recursively from the root */
+ debugfs_remove_recursive(hot_debugfs_root_dentry);
+}
+
/*
* Initialize kmem cache for hot_inode_item and hot_range_item.
*/
@@ -832,6 +1286,13 @@ void hot_track_init(struct super_block *sb)
root->hot_shrink.seeks = DEFAULT_SEEKS;
register_shrinker(&root->hot_shrink);
+ err = hot_debugfs_init(sb);
+ if (err) {
+ printk(KERN_ERR "%s: hot_debugfs_init error: %d\n",
+ __func__, err);
+ return;
+ }
+
printk(KERN_INFO "vfs: turning on hot data tracking\n");
return;
@@ -855,5 +1316,6 @@ void hot_track_exit(struct super_block *sb)
hot_inode_tree_exit(root);
sb->hot_flags &= ~MS_HOT_TRACKING;
hot_cache_exit();
+ hot_debugfs_exit(sb);
kfree(root);
}
diff --git a/fs/hot_tracking.h b/fs/hot_tracking.h
index 7a79a6d..76d7469 100644
--- a/fs/hot_tracking.h
+++ b/fs/hot_tracking.h
@@ -92,6 +92,49 @@
#define AVW_DIVIDER_POWER 40
#define AVW_COEFF_POWER 0
+/* size of log to vmalloc */
+#define INIT_LOG_ALLOC_SIZE (PAGE_SIZE * 10)
+#define LOG_PAGE_SIZE (PAGE_SIZE * 10)
+
+/*
+ * number of chars of device name of chop off
+ * for making debugfs folder e.g. /dev/sda -> sda
+ */
+#define DEV_NAME_CHOP 5
+
+/*
+ * Name for VFS data in debugfs directory
+ * e.g. /sys/kernel/debug/hot_track
+ */
+#define DEBUGFS_ROOT_NAME "hot_track"
+
+/* log to output to userspace in debugfs files */
+struct lstring {
+ char *str;
+ unsigned long len;
+};
+
+/*
+ * debugfs_vol_data is a struct of items
+ * that is passed to the debugfs
+ */
+struct debugfs_vol_data {
+ /* protected by hot_debugfs_data_list_lock */
+ struct list_head node;
+ struct lstring *debugfs_log;
+ struct super_block *sb;
+ struct dentry *de;
+ /* protects debugfs_log */
+ spinlock_t log_lock;
+ char log_work_buff[1024];
+ uint log_alloc_size;
+};
+
+typedef void (*hot_debugfs_walk_t)(
+ struct hot_inode_item *hot_inode,
+ struct debugfs_vol_data *data,
+ struct hot_info *root);
+
struct hot_update_work {
struct work_struct work;
struct hot_info *hot_info;
--
1.7.6.5
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