From patchwork Wed Oct 10 10:07:34 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhiyong Wu X-Patchwork-Id: 190593 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id AE0382C0089 for ; Wed, 10 Oct 2012 21:10:04 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755512Ab2JJKJs (ORCPT ); Wed, 10 Oct 2012 06:09:48 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:53863 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755346Ab2JJKJo (ORCPT ); Wed, 10 Oct 2012 06:09:44 -0400 Received: from /spool/local by e4.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 10 Oct 2012 06:09:21 -0400 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay06.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q9AA9KAh34734116; Wed, 10 Oct 2012 06:09:20 -0400 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q9AA9Jp3029729; Wed, 10 Oct 2012 07:09:20 -0300 Received: from us.ibm.com (f15.cn.ibm.com [9.115.122.193]) by d01av02.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with SMTP id q9AA9ECw029372; Wed, 10 Oct 2012 07:09:15 -0300 Received: by us.ibm.com (sSMTP sendmail emulation); Wed, 10 Oct 2012 18:09:14 +0800 From: zwu.kernel@gmail.com To: linux-fsdevel@vger.kernel.org Cc: linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linuxram@linux.vnet.ibm.com, viro@zeniv.linux.org.uk, david@fromorbit.com, dave@jikos.cz, tytso@mit.edu, cmm@us.ibm.com, Zhi Yong Wu Subject: [RFC v3 12/13] vfs: add debugfs support Date: Wed, 10 Oct 2012 18:07:34 +0800 Message-Id: <1349863655-29320-13-git-send-email-zwu.kernel@gmail.com> X-Mailer: git-send-email 1.7.6.5 In-Reply-To: <1349863655-29320-1-git-send-email-zwu.kernel@gmail.com> References: <1349863655-29320-1-git-send-email-zwu.kernel@gmail.com> x-cbid: 12101010-3534-0000-0000-00000DA50994 Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Zhi Yong Wu Add a /sys/kernel/debug/hot_track// 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 --- 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 #include #include +#include +#include #include #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;