linux/fs/netfs/main.c
David Howells 87b57a0489 netfs: Add a procfile to list in-progress requests
Add a procfile, /proc/fs/netfs/requests, to list in-progress netfslib I/O
requests.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: linux-cachefs@redhat.com
cc: linux-fsdevel@vger.kernel.org
cc: linux-mm@kvack.org
2023-12-24 15:08:49 +00:00

122 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* Miscellaneous bits for the netfs support library.
*
* Copyright (C) 2022 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <linux/module.h>
#include <linux/export.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include "internal.h"
#define CREATE_TRACE_POINTS
#include <trace/events/netfs.h>
MODULE_DESCRIPTION("Network fs support");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");
unsigned netfs_debug;
module_param_named(debug, netfs_debug, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(netfs_debug, "Netfs support debugging mask");
#ifdef CONFIG_PROC_FS
LIST_HEAD(netfs_io_requests);
DEFINE_SPINLOCK(netfs_proc_lock);
static const char *netfs_origins[] = {
[NETFS_READAHEAD] = "RA",
[NETFS_READPAGE] = "RP",
[NETFS_READ_FOR_WRITE] = "RW",
};
/*
* Generate a list of I/O requests in /proc/fs/netfs/requests
*/
static int netfs_requests_seq_show(struct seq_file *m, void *v)
{
struct netfs_io_request *rreq;
if (v == &netfs_io_requests) {
seq_puts(m,
"REQUEST OR REF FL ERR OPS COVERAGE\n"
"======== == === == ==== === =========\n"
);
return 0;
}
rreq = list_entry(v, struct netfs_io_request, proc_link);
seq_printf(m,
"%08x %s %3d %2lx %4d %3d @%04llx %zx/%zx",
rreq->debug_id,
netfs_origins[rreq->origin],
refcount_read(&rreq->ref),
rreq->flags,
rreq->error,
atomic_read(&rreq->nr_outstanding),
rreq->start, rreq->submitted, rreq->len);
seq_putc(m, '\n');
return 0;
}
static void *netfs_requests_seq_start(struct seq_file *m, loff_t *_pos)
__acquires(rcu)
{
rcu_read_lock();
return seq_list_start_head(&netfs_io_requests, *_pos);
}
static void *netfs_requests_seq_next(struct seq_file *m, void *v, loff_t *_pos)
{
return seq_list_next(v, &netfs_io_requests, _pos);
}
static void netfs_requests_seq_stop(struct seq_file *m, void *v)
__releases(rcu)
{
rcu_read_unlock();
}
static const struct seq_operations netfs_requests_seq_ops = {
.start = netfs_requests_seq_start,
.next = netfs_requests_seq_next,
.stop = netfs_requests_seq_stop,
.show = netfs_requests_seq_show,
};
#endif /* CONFIG_PROC_FS */
static int __init netfs_init(void)
{
int ret = -ENOMEM;
if (!proc_mkdir("fs/netfs", NULL))
goto error;
if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL,
&netfs_requests_seq_ops))
goto error_proc;
#ifdef CONFIG_FSCACHE_STATS
if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL,
netfs_stats_show))
goto error_proc;
#endif
ret = fscache_init();
if (ret < 0)
goto error_proc;
return 0;
error_proc:
remove_proc_entry("fs/netfs", NULL);
error:
return ret;
}
fs_initcall(netfs_init);
static void __exit netfs_exit(void)
{
fscache_exit();
remove_proc_entry("fs/netfs", NULL);
}
module_exit(netfs_exit);