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// 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/mempool.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");
EXPORT_TRACEPOINT_SYMBOL(netfs_sreq);
static struct kmem_cache *netfs_request_slab;
static struct kmem_cache *netfs_subrequest_slab;
mempool_t netfs_request_pool;
mempool_t netfs_subrequest_pool;
#ifdef CONFIG_PROC_FS
LIST_HEAD(netfs_io_requests);
DEFINE_SPINLOCK(netfs_proc_lock);
static const char *netfs_origins[nr__netfs_io_origin] = {
[NETFS_READAHEAD] = "RA",
[NETFS_READPAGE] = "RP",
[NETFS_READ_FOR_WRITE] = "RW",
[NETFS_COPY_TO_CACHE] = "CC",
[NETFS_WRITEBACK] = "WB",
[NETFS_WRITETHROUGH] = "WT",
[NETFS_UNBUFFERED_WRITE] = "UW",
[NETFS_DIO_READ] = "DR",
[NETFS_DIO_WRITE] = "DW",
};
/*
* 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 %llx/%llx",
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;
netfs_request_slab = kmem_cache_create("netfs_request",
sizeof(struct netfs_io_request), 0,
SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT,
NULL);
if (!netfs_request_slab)
goto error_req;
if (mempool_init_slab_pool(&netfs_request_pool, 100, netfs_request_slab) < 0)
goto error_reqpool;
netfs_subrequest_slab = kmem_cache_create("netfs_subrequest",
sizeof(struct netfs_io_subrequest), 0,
SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT,
NULL);
if (!netfs_subrequest_slab)
goto error_subreq;
if (mempool_init_slab_pool(&netfs_subrequest_pool, 100, netfs_subrequest_slab) < 0)
goto error_subreqpool;
if (!proc_mkdir("fs/netfs", NULL))
goto error_proc;
if (!proc_create_seq("fs/netfs/requests", S_IFREG | 0444, NULL,
&netfs_requests_seq_ops))
goto error_procfile;
#ifdef CONFIG_FSCACHE_STATS
if (!proc_create_single("fs/netfs/stats", S_IFREG | 0444, NULL,
netfs_stats_show))
goto error_procfile;
#endif
ret = fscache_init();
if (ret < 0)
goto error_fscache;
return 0;
error_fscache:
error_procfile:
remove_proc_entry("fs/netfs", NULL);
error_proc:
mempool_exit(&netfs_subrequest_pool);
error_subreqpool:
kmem_cache_destroy(netfs_subrequest_slab);
error_subreq:
mempool_exit(&netfs_request_pool);
error_reqpool:
kmem_cache_destroy(netfs_request_slab);
error_req:
return ret;
}
fs_initcall(netfs_init);
static void __exit netfs_exit(void)
{
fscache_exit();
remove_proc_entry("fs/netfs", NULL);
mempool_exit(&netfs_subrequest_pool);
kmem_cache_destroy(netfs_subrequest_slab);
mempool_exit(&netfs_request_pool);
kmem_cache_destroy(netfs_request_slab);
}
module_exit(netfs_exit);
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