[RFC v2 83/83] Sysfs support.

Andiry Xu
2018-03-10T18:22:26Z

Sysfs support allows user to get/post information of running NOVA instance.
After mount, NOVA creates four entries under proc directory
/proc/fs/nova/pmem#/:

timing_stats IO_stats allocator gc

Show NOVA file operation timing statistics:
cat /proc/fs/NOVA/pmem#/timing_stats

Clear timing statistics:
echo 1 > /proc/fs/NOVA/pmem#/timing_stats

Show NOVA I/O statistics:
cat /proc/fs/NOVA/pmem#/IO_stats

Clear I/O statistics:
echo 1 > /proc/fs/NOVA/pmem#/IO_stats

Show NOVA allocator information:
cat /proc/fs/NOVA/pmem#/allocator

Manual garbage collection:
echo #inode_number > /proc/fs/NOVA/pmem#/gc

Signed-off-by: Andiry Xu <jix024@cs.ucsd.edu>
---
fs/nova/Makefile | 2 +-
fs/nova/nova.h | 6 +
fs/nova/super.c | 9 ++
fs/nova/super.h | 1 +
fs/nova/sysfs.c | 379 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 396 insertions(+), 1 deletion(-)
create mode 100644 fs/nova/sysfs.c

diff --git a/fs/nova/Makefile b/fs/nova/Makefile
index 7a5fb6d..6e1c29d 100644
--- a/fs/nova/Makefile
+++ b/fs/nova/Makefile
@@ -5,4 +5,4 @@
obj-$(CONFIG_NOVA_FS) += nova.o

nova-y := balloc.o bbuild.o dax.o dir.o file.o gc.o inode.o ioctl.o journal.o\
- log.o namei.o rebuild.o stats.o super.o symlink.o
+ log.o namei.o rebuild.o stats.o super.o symlink.o sysfs.o
diff --git a/fs/nova/nova.h b/fs/nova/nova.h
index 32b7b2f..0814676 100644
--- a/fs/nova/nova.h
+++ b/fs/nova/nova.h
@@ -546,6 +546,12 @@ int nova_block_symlink(struct super_block *sb, struct nova_inode *pi,
struct inode *inode, const char *symname, int len, u64 epoch_id);
extern const struct inode_operations nova_symlink_inode_operations;

+/* sysfs.c */
+extern const char *proc_dirname;
+extern struct proc_dir_entry *nova_proc_root;
+void nova_sysfs_init(struct super_block *sb);
+void nova_sysfs_exit(struct super_block *sb);
+
/* stats.c */
void nova_get_timing_stats(void);
void nova_get_IO_stats(void);
diff --git a/fs/nova/super.c b/fs/nova/super.c
index 14b4af6..039c003 100644
--- a/fs/nova/super.c
+++ b/fs/nova/super.c
@@ -596,6 +596,8 @@ static int nova_fill_super(struct super_block *sb, void *data, int silent)
goto out;
}

+ nova_sysfs_init(sb);
+
/* Init a new nova instance */
if (sbi->s_mount_opt & NOVA_MOUNT_FORMAT) {
root_pi = nova_init(sb, sbi->initsize);
@@ -680,6 +682,8 @@ static int nova_fill_super(struct super_block *sb, void *data, int silent)
kfree(sbi->inode_maps);
sbi->inode_maps = NULL;

+ nova_sysfs_exit(sb);
+
kfree(sbi->nova_sb);
kfree(sbi);
nova_dbg("%s failed: return %d\n", __func__, retval);
@@ -783,6 +787,8 @@ static void nova_put_super(struct super_block *sb)
i, inode_map->allocated, inode_map->freed);
}

+ nova_sysfs_exit(sb);
+
kfree(sbi->inode_maps);
kfree(sbi->nova_sb);
kfree(sbi);
@@ -1007,6 +1013,8 @@ static int __init init_nova_fs(void)
nova_info("Arch new instructions support: CLWB %s\n",
support_clwb ? "YES" : "NO");

+ nova_proc_root = proc_mkdir(proc_dirname, NULL);
+
rc = init_rangenode_cache();
if (rc)
goto out;
@@ -1041,6 +1049,7 @@ static int __init init_nova_fs(void)
static void __exit exit_nova_fs(void)
{
unregister_filesystem(&nova_fs_type);
+ remove_proc_entry(proc_dirname, NULL);
destroy_file_write_item_cache();
destroy_inodecache();
destroy_rangenode_cache();
diff --git a/fs/nova/super.h b/fs/nova/super.h
index bcf9548..bcbe862 100644
--- a/fs/nova/super.h
+++ b/fs/nova/super.h
@@ -112,6 +112,7 @@ struct nova_sb_info {
struct mutex s_lock; /* protects the SB's buffer-head */

int cpus;
+ struct proc_dir_entry *s_proc;

/* Current epoch. volatile guarantees visibility */
volatile u64 s_epoch_id;
diff --git a/fs/nova/sysfs.c b/fs/nova/sysfs.c
new file mode 100644
index 0000000..0a73ef4
--- /dev/null
+++ b/fs/nova/sysfs.c
@@ -0,0 +1,379 @@
+/*
+ * BRIEF DESCRIPTION
+ *
+ * Proc fs operations
+ *
+ * Copyright 2015-2016 Regents of the University of California,
+ * UCSD Non-Volatile Systems Lab, Andiry Xu <jix024@cs.ucsd.edu>
+ * Copyright 2012-2013 Intel Corporation
+ * Copyright 2009-2011 Marco Stornelli <marco.stornelli@gmail.com>
+ * Copyright 2003 Sony Corporation
+ * Copyright 2003 Matsushita Electric Industrial Co., Ltd.
+ * 2003-2004 (c) MontaVista Software, Inc. , Steve Longerbeam
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include "nova.h"
+#include "inode.h"
+
+const char *proc_dirname = "fs/NOVA";
+struct proc_dir_entry *nova_proc_root;
+
+/* ====================== Statistics ======================== */
+static int nova_seq_timing_show(struct seq_file *seq, void *v)
+{
+ int i;
+
+ nova_get_timing_stats();
+
+ seq_puts(seq, "=========== NOVA kernel timing stats ===========\n");
+ for (i = 0; i < TIMING_NUM; i++) {
+ /* Title */
+ if (Timingstring[i][0] == '=') {
+ seq_printf(seq, "\n%s\n\n", Timingstring[i]);
+ continue;
+ }
+
+ if (measure_timing || Timingstats[i]) {
+ seq_printf(seq, "%s: count %llu, timing %llu, average %llu\n",
+ Timingstring[i],
+ Countstats[i],
+ Timingstats[i],
+ Countstats[i] ?
+ Timingstats[i] / Countstats[i] : 0);
+ } else {
+ seq_printf(seq, "%s: count %llu\n",
+ Timingstring[i],
+ Countstats[i]);
+ }
+ }
+
+ seq_puts(seq, "\n");
+ return 0;
+}
+
+static int nova_seq_timing_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, nova_seq_timing_show, PDE_DATA(inode));
+}
+
+ssize_t nova_seq_clear_stats(struct file *filp, const char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ struct address_space *mapping = filp->f_mapping;
+ struct inode *inode = mapping->host;
+ struct super_block *sb = PDE_DATA(inode);
+
+ nova_clear_stats(sb);
+ return len;
+}
+
+static const struct file_operations nova_seq_timing_fops = {
+ .owner = THIS_MODULE,
+ .open = nova_seq_timing_open,
+ .read = seq_read,
+ .write = nova_seq_clear_stats,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int nova_seq_IO_show(struct seq_file *seq, void *v)
+{
+ struct super_block *sb = seq->private;
+ struct nova_sb_info *sbi = NOVA_SB(sb);
+ struct free_list *free_list;
+ unsigned long alloc_log_count = 0;
+ unsigned long alloc_log_pages = 0;
+ unsigned long alloc_data_count = 0;
+ unsigned long alloc_data_pages = 0;
+ unsigned long free_log_count = 0;
+ unsigned long freed_log_pages = 0;
+ unsigned long free_data_count = 0;
+ unsigned long freed_data_pages = 0;
+ int i;
+
+ nova_get_timing_stats();
+ nova_get_IO_stats();
+
+ seq_puts(seq, "============ NOVA allocation stats ============\n\n");
+
+ for (i = 0; i < sbi->cpus; i++) {
+ free_list = nova_get_free_list(sb, i);
+
+ alloc_log_count += free_list->alloc_log_count;
+ alloc_log_pages += free_list->alloc_log_pages;
+ alloc_data_count += free_list->alloc_data_count;
+ alloc_data_pages += free_list->alloc_data_pages;
+ free_log_count += free_list->free_log_count;
+ freed_log_pages += free_list->freed_log_pages;
+ free_data_count += free_list->free_data_count;
+ freed_data_pages += free_list->freed_data_pages;
+ }
+
+ seq_printf(seq, "alloc log count %lu, allocated log pages %lu\n"
+ "alloc data count %lu, allocated data pages %lu\n"
+ "free log count %lu, freed log pages %lu\n"
+ "free data count %lu, freed data pages %lu\n",
+ alloc_log_count, alloc_log_pages,
+ alloc_data_count, alloc_data_pages,
+ free_log_count, freed_log_pages,
+ free_data_count, freed_data_pages);
+
+ seq_printf(seq, "Fast GC %llu, check pages %llu, free pages %llu, average %llu\n",
+ Countstats[fast_gc_t], IOstats[fast_checked_pages],
+ IOstats[fast_gc_pages], Countstats[fast_gc_t] ?
+ IOstats[fast_gc_pages] / Countstats[fast_gc_t] : 0);
+ seq_printf(seq, "Thorough GC %llu, checked pages %llu, free pages %llu, average %llu\n",
+ Countstats[thorough_gc_t],
+ IOstats[thorough_checked_pages], IOstats[thorough_gc_pages],
+ Countstats[thorough_gc_t] ?
+ IOstats[thorough_gc_pages] / Countstats[thorough_gc_t]
+ : 0);
+
+ seq_puts(seq, "\n");
+
+ seq_puts(seq, "================ NOVA I/O stats ================\n\n");
+ seq_printf(seq, "Read %llu, bytes %llu, average %llu\n",
+ Countstats[dax_read_t], IOstats[read_bytes],
+ Countstats[dax_read_t] ?
+ IOstats[read_bytes] / Countstats[dax_read_t] : 0);
+ seq_printf(seq, "COW write %llu, bytes %llu, average %llu, write breaks %llu, average %llu\n",
+ Countstats[cow_write_t], IOstats[cow_write_bytes],
+ Countstats[cow_write_t] ?
+ IOstats[cow_write_bytes] / Countstats[cow_write_t] : 0,
+ IOstats[cow_write_breaks], Countstats[cow_write_t] ?
+ IOstats[cow_write_breaks] / Countstats[cow_write_t]
+ : 0);
+ seq_printf(seq, "Inplace write %llu, bytes %llu, average %llu, write breaks %llu, average %llu\n",
+ Countstats[inplace_write_t], IOstats[inplace_write_bytes],
+ Countstats[inplace_write_t] ?
+ IOstats[inplace_write_bytes] /
+ Countstats[inplace_write_t] : 0,
+ IOstats[inplace_write_breaks], Countstats[inplace_write_t] ?
+ IOstats[inplace_write_breaks] /
+ Countstats[inplace_write_t] : 0);
+ seq_printf(seq, "Inplace write %llu, allocate new blocks %llu\n",
+ Countstats[inplace_write_t],
+ IOstats[inplace_new_blocks]);
+ seq_printf(seq, "DAX get blocks %llu, allocate new blocks %llu\n",
+ Countstats[dax_get_block_t], IOstats[dax_new_blocks]);
+ seq_printf(seq, "Page fault %llu\n", Countstats[mmap_fault_t]);
+ seq_printf(seq, "fsync %llu, fdatasync %llu\n",
+ Countstats[fsync_t], IOstats[fdatasync]);
+
+ seq_puts(seq, "\n");
+
+ return 0;
+}
+
+static int nova_seq_IO_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, nova_seq_IO_show, PDE_DATA(inode));
+}
+
+static const struct file_operations nova_seq_IO_fops = {
+ .owner = THIS_MODULE,
+ .open = nova_seq_IO_open,
+ .read = seq_read,
+ .write = nova_seq_clear_stats,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int nova_seq_show_allocator(struct seq_file *seq, void *v)
+{
+ struct super_block *sb = seq->private;
+ struct nova_sb_info *sbi = NOVA_SB(sb);
+ struct free_list *free_list;
+ int i;
+ unsigned long log_pages = 0;
+ unsigned long data_pages = 0;
+
+ seq_puts(seq, "======== NOVA per-CPU allocator stats ========\n");
+ for (i = 0; i < sbi->cpus; i++) {
+ free_list = nova_get_free_list(sb, i);
+ seq_printf(seq, "Free list %d: block start %lu, block end %lu, num_blocks %lu, num_free_blocks %lu, blocknode %lu\n",
+ i, free_list->block_start, free_list->block_end,
+ free_list->block_end - free_list->block_start + 1,
+ free_list->num_free_blocks, free_list->num_blocknode);
+
+ if (free_list->first_node) {
+ seq_printf(seq, "First node %lu - %lu\n",
+ free_list->first_node->range_low,
+ free_list->first_node->range_high);
+ }
+
+ if (free_list->last_node) {
+ seq_printf(seq, "Last node %lu - %lu\n",
+ free_list->last_node->range_low,
+ free_list->last_node->range_high);
+ }
+
+ seq_printf(seq, "Free list %d: alloc log count %lu, allocated log pages %lu, alloc data count %lu, allocated data pages %lu, free log count %lu, freed log pages %lu, free data count %lu, freed data pages %lu\n",
+ i,
+ free_list->alloc_log_count,
+ free_list->alloc_log_pages,
+ free_list->alloc_data_count,
+ free_list->alloc_data_pages,
+ free_list->free_log_count,
+ free_list->freed_log_pages,
+ free_list->free_data_count,
+ free_list->freed_data_pages);
+
+ log_pages += free_list->alloc_log_pages;
+ log_pages -= free_list->freed_log_pages;
+
+ data_pages += free_list->alloc_data_pages;
+ data_pages -= free_list->freed_data_pages;
+ }
+
+ seq_printf(seq, "\nCurrently used pmem pages: log %lu, data %lu\n",
+ log_pages, data_pages);
+
+ return 0;
+}
+
+static int nova_seq_allocator_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, nova_seq_show_allocator,
+ PDE_DATA(inode));
+}
+
+static const struct file_operations nova_seq_allocator_fops = {
+ .owner = THIS_MODULE,
+ .open = nova_seq_allocator_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+
+/* ====================== GC ======================== */
+
+
+static int nova_seq_gc_show(struct seq_file *seq, void *v)
+{
+ seq_printf(seq, "Echo inode number to trigger garbage collection\n"
+ " example: echo 34 > /proc/fs/NOVA/pmem0/gc\n");
+ return 0;
+}
+
+static int nova_seq_gc_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, nova_seq_gc_show, PDE_DATA(inode));
+}
+
+ssize_t nova_seq_gc(struct file *filp, const char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ u64 target_inode_number;
+ struct address_space *mapping = filp->f_mapping;
+ struct inode *inode = mapping->host;
+ struct super_block *sb = PDE_DATA(inode);
+ struct inode *target_inode;
+ struct nova_inode *target_pi;
+ struct nova_inode_info *target_sih;
+
+ int ret;
+ char *_buf;
+ int retval = len;
+
+ _buf = kmalloc(len, GFP_KERNEL);
+ if (_buf == NULL) {
+ retval = -ENOMEM;
+ nova_dbg("%s: kmalloc failed\n", __func__);
+ goto out;
+ }
+
+ if (copy_from_user(_buf, buf, len)) {
+ retval = -EFAULT;
+ goto out;
+ }
+
+ _buf[len] = 0;
+ ret = kstrtoull(_buf, 0, &target_inode_number);
+ if (ret) {
+ nova_info("%s: Could not parse ino '%s'\n", __func__, _buf);
+ return ret;
+ }
+ nova_info("%s: target_inode_number=%llu.", __func__,
+ target_inode_number);
+
+ target_inode = nova_iget(sb, target_inode_number);
+ if (target_inode == NULL) {
+ nova_info("%s: inode %llu does not exist.", __func__,
+ target_inode_number);
+ retval = -ENOENT;
+ goto out;
+ }
+
+ target_pi = nova_get_inode(sb, target_inode);
+ if (target_pi == NULL) {
+ nova_info("%s: couldn't get nova inode %llu.", __func__,
+ target_inode_number);
+ retval = -ENOENT;
+ goto out;
+ }
+
+ target_sih = NOVA_I(target_inode);
+
+ nova_info("%s: got inode %llu @ 0x%p; pi=0x%p\n", __func__,
+ target_inode_number, target_inode, target_pi);
+
+ nova_inode_log_fast_gc(sb, target_pi, &target_sih->header,
+ 0, 0, 0, 1);
+ iput(target_inode);
+
+out:
+ kfree(_buf);
+ return retval;
+}
+
+static const struct file_operations nova_seq_gc_fops = {
+ .owner = THIS_MODULE,
+ .open = nova_seq_gc_open,
+ .read = seq_read,
+ .write = nova_seq_gc,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+/* ====================== Setup/teardown======================== */
+void nova_sysfs_init(struct super_block *sb)
+{
+ struct nova_sb_info *sbi = NOVA_SB(sb);
+
+ if (nova_proc_root)
+ sbi->s_proc = proc_mkdir(sbi->s_bdev->bd_disk->disk_name,
+ nova_proc_root);
+
+ if (sbi->s_proc) {
+ proc_create_data("timing_stats", 0444, sbi->s_proc,
+ &nova_seq_timing_fops, sb);
+ proc_create_data("IO_stats", 0444, sbi->s_proc,
+ &nova_seq_IO_fops, sb);
+ proc_create_data("allocator", 0444, sbi->s_proc,
+ &nova_seq_allocator_fops, sb);
+ proc_create_data("gc", 0444, sbi->s_proc,
+ &nova_seq_gc_fops, sb);
+ }
+}
+
+void nova_sysfs_exit(struct super_block *sb)
+{
+ struct nova_sb_info *sbi = NOVA_SB(sb);
+
+ if (sbi->s_proc) {
+ remove_proc_entry("timing_stats", sbi->s_proc);
+ remove_proc_entry("IO_stats", sbi->s_proc);
+ remove_proc_entry("allocator", sbi->s_proc);
+ remove_proc_entry("gc", sbi->s_proc);
+ remove_proc_entry(sbi->s_bdev->bd_disk->disk_name,
+ nova_proc_root);
+ }
+}
--
2.7.4