Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964787Ab2EQQZp (ORCPT ); Thu, 17 May 2012 12:25:45 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]:44579 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760514Ab2EQQZj (ORCPT ); Thu, 17 May 2012 12:25:39 -0400 Message-Id: <20120517162534.840623571@openvz.org> User-Agent: quilt/0.48-1 Date: Thu, 17 May 2012 20:07:42 +0400 From: Cyrill Gorcunov To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Pavel Emelyanov , James Bottomley , linux-fsdevel@vger.kernel.org, Cyrill Gorcunov Subject: [rfc 4/4] fs, epoll: Add procfs fdinfo helper References: <20120517160738.116113099@openvz.org> Content-Disposition: inline; filename=seq-fdinfo-eventpoll-2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3321 Lines: 125 This allow us to print out eventpoll target file descriptor, events and data, so the /proc/pid/fdinfo/fd consists of | pos: 0 | flags: 02 | tfd: 5 events: 1d data: ffffffffffffffff Signed-off-by: Cyrill Gorcunov --- fs/eventpoll.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 82 insertions(+) Index: linux-2.6.git/fs/eventpoll.c =================================================================== --- linux-2.6.git.orig/fs/eventpoll.c +++ linux-2.6.git/fs/eventpoll.c @@ -37,6 +37,8 @@ #include #include #include +#include +#include /* * LOCKING: @@ -1815,6 +1817,84 @@ SYSCALL_DEFINE6(epoll_pwait, int, epfd, #endif /* HAVE_SET_RESTORE_SIGMASK */ +#ifdef CONFIG_PROC_FS + +#define FDINFO_SEQ_UNLOCKED (void *)(0L) +#define FDINFO_SEQ_LOCKED (void *)(1L) + +static struct epitem * +seq_lookup_epi(struct proc_fdinfo_extra *extra, struct eventpoll *ep, loff_t num) +{ + struct rb_node *rbp; + + if (extra->private == FDINFO_SEQ_UNLOCKED) { + mutex_lock(&ep->mtx); + extra->private = FDINFO_SEQ_LOCKED; + } + + for (rbp = rb_first(&ep->rbr); rbp; rbp = rb_next(rbp)) { + if (num-- == 0) + return rb_entry(rbp, struct epitem, rbn); + } + + return NULL; +} + +static void *seq_start(struct seq_file *m, loff_t *pos) +{ + struct proc_fdinfo_extra *extra = m->private; + struct eventpoll *ep = extra->fd_file->private_data; + + return *pos ? seq_lookup_epi(extra, ep, *pos - 1) : NULL; +} + +static void seq_stop(struct seq_file *m, void *v) +{ + struct proc_fdinfo_extra *extra = m->private; + struct eventpoll *ep = extra->fd_file->private_data; + + if (extra->private == FDINFO_SEQ_LOCKED) + mutex_unlock(&ep->mtx); + extra->private = FDINFO_SEQ_UNLOCKED; +} + +static void *seq_next(struct seq_file *m, void *p, loff_t *pos) +{ + struct proc_fdinfo_extra *extra = m->private; + struct eventpoll *ep = extra->fd_file->private_data; + ++*pos; + return (void *)seq_lookup_epi(extra, ep, *pos - 1); +} + +static int seq_show(struct seq_file *m, void *v) +{ + struct epitem *epi = v; + seq_printf(m, "tfd: %8d events: %8x data: %16llx\n", + epi->ffd.fd, epi->event.events, (long long)epi->event.data); + return 0; +} + +static const struct seq_operations ep_fdinfo_ops = { + .start = seq_start, + .next = seq_next, + .stop = seq_stop, + .show = seq_show, +}; + +static struct proc_fdinfo_helper ep_fdinfo_helper = { + .name = "epoll", + .ops = &ep_fdinfo_ops, + .probe = is_file_epoll, +}; + +static int __init ep_register_fdinfo_helper(void) +{ + return proc_register_fdinfo_helper(&ep_fdinfo_helper); +} +#else +static void ep_register_fdinfo_helper(void) { } +#endif /* CONFIG_PROC_FS */ + static int __init eventpoll_init(void) { struct sysinfo si; @@ -1847,6 +1927,8 @@ static int __init eventpoll_init(void) pwq_cache = kmem_cache_create("eventpoll_pwq", sizeof(struct eppoll_entry), 0, SLAB_PANIC, NULL); + ep_register_fdinfo_helper(); + return 0; } fs_initcall(eventpoll_init); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/