Commit 87b57a04 authored by David Howells's avatar David Howells
Browse files

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: default avatarDavid 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
parent c9c4ff12

fs/netfs/internal.h

+22 −0
Original line number Diff line number Diff line
@@ -33,6 +33,28 @@ int netfs_begin_read(struct netfs_io_request *rreq, bool sync); 
 * main.c

 */

extern unsigned int netfs_debug;

extern struct list_head netfs_io_requests;

extern spinlock_t netfs_proc_lock;



#ifdef CONFIG_PROC_FS

static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq)

{

	spin_lock(&netfs_proc_lock);

	list_add_tail_rcu(&rreq->proc_link, &netfs_io_requests);

	spin_unlock(&netfs_proc_lock);

}

static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq)

{

	if (!list_empty(&rreq->proc_link)) {

		spin_lock(&netfs_proc_lock);

		list_del_rcu(&rreq->proc_link);

		spin_unlock(&netfs_proc_lock);

	}

}

#else

static inline void netfs_proc_add_rreq(struct netfs_io_request *rreq) {}

static inline void netfs_proc_del_rreq(struct netfs_io_request *rreq) {}

#endif



/*

 * objects.c

fs/netfs/main.c

+68 −1
Original line number Diff line number Diff line
@@ -21,13 +21,80 @@ 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))

fs/netfs/objects.c

+3 −1
Original line number Diff line number Diff line
@@ -45,6 +45,7 @@ struct netfs_io_request *netfs_alloc_request(struct address_space *mapping, 
		}

	}



	netfs_proc_add_rreq(rreq);

	netfs_stat(&netfs_n_rh_rreq);

	return rreq;

}
@@ -76,12 +77,13 @@ static void netfs_free_request(struct work_struct *work) 
		container_of(work, struct netfs_io_request, work);



	trace_netfs_rreq(rreq, netfs_rreq_trace_free);

	netfs_proc_del_rreq(rreq);

	netfs_clear_subrequests(rreq, false);

	if (rreq->netfs_ops->free_request)

		rreq->netfs_ops->free_request(rreq);

	if (rreq->cache_resources.ops)

		rreq->cache_resources.ops->end_operation(&rreq->cache_resources);

	kfree(rreq);

	kfree_rcu(rreq, rcu);

	netfs_stat_d(&netfs_n_rh_rreq);

}

include/linux/netfs.h

+5 −1
Original line number Diff line number Diff line
@@ -175,10 +175,14 @@ enum netfs_io_origin { 
 * operations to a variety of data stores and then stitch the result together.

 */

struct netfs_io_request {

	union {

		struct work_struct work;

		struct rcu_head rcu;

	};

	struct inode		*inode;		/* The file being accessed */

	struct address_space	*mapping;	/* The mapping being accessed */

	struct netfs_cache_resources cache_resources;

	struct list_head	proc_link;	/* Link in netfs_iorequests */

	struct list_head	subrequests;	/* Contributory I/O operations */

	void			*netfs_priv;	/* Private data for the netfs */

	unsigned int		debug_id;