From 912a846027c203370f4837a2b2db7ba2ebe1b47c Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 21 May 2018 14:35:12 +1000 Subject: [PATCH] staging: lustre: replace libcfs_register_ioctl with a blocking notifier_chain libcfs allows other modules to register handlers for ioctls. The implementation it uses for this is nearly identical to a blocking notifier chain, so change to use that. The biggest difference is that the return value from notifier has a defined format, where libcfs_register_ioctl uses -EINVAL to mean "continue". This requires a little bit of conversion. Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman --- .../lustre/include/linux/libcfs/libcfs.h | 19 ++---- drivers/staging/lustre/lnet/libcfs/module.c | 64 ++++--------------- drivers/staging/lustre/lnet/lnet/module.c | 38 +++++++---- drivers/staging/lustre/lnet/selftest/conctl.c | 27 ++++---- .../staging/lustre/lnet/selftest/console.c | 10 ++- .../staging/lustre/lnet/selftest/console.h | 3 +- 6 files changed, 70 insertions(+), 91 deletions(-) diff --git a/drivers/staging/lustre/include/linux/libcfs/libcfs.h b/drivers/staging/lustre/include/linux/libcfs/libcfs.h index d9002e7424d4..63ea0e99ec58 100644 --- a/drivers/staging/lustre/include/linux/libcfs/libcfs.h +++ b/drivers/staging/lustre/include/linux/libcfs/libcfs.h @@ -93,19 +93,14 @@ #define LNET_ACCEPTOR_MIN_RESERVED_PORT 512 #define LNET_ACCEPTOR_MAX_RESERVED_PORT 1023 -struct libcfs_ioctl_handler { - struct list_head item; - int (*handle_ioctl)(unsigned int cmd, struct libcfs_ioctl_hdr *hdr); -}; - -#define DECLARE_IOCTL_HANDLER(ident, func) \ - struct libcfs_ioctl_handler ident = { \ - .item = LIST_HEAD_INIT(ident.item), \ - .handle_ioctl = func \ - } +extern struct blocking_notifier_head libcfs_ioctl_list; +static inline int notifier_from_ioctl_errno(int err) +{ + if (err == -EINVAL) + return NOTIFY_OK; + return notifier_from_errno(err) | NOTIFY_STOP_MASK; +} -int libcfs_register_ioctl(struct libcfs_ioctl_handler *hand); -int libcfs_deregister_ioctl(struct libcfs_ioctl_handler *hand); int libcfs_setup(void); #define _LIBCFS_H diff --git a/drivers/staging/lustre/lnet/libcfs/module.c b/drivers/staging/lustre/lnet/libcfs/module.c index 3e51aae751c5..b3a7c1a912ba 100644 --- a/drivers/staging/lustre/lnet/libcfs/module.c +++ b/drivers/staging/lustre/lnet/libcfs/module.c @@ -62,38 +62,8 @@ static struct dentry *lnet_debugfs_root; -static DECLARE_RWSEM(ioctl_list_sem); -static LIST_HEAD(ioctl_list); - -int libcfs_register_ioctl(struct libcfs_ioctl_handler *hand) -{ - int rc = 0; - - down_write(&ioctl_list_sem); - if (!list_empty(&hand->item)) - rc = -EBUSY; - else - list_add_tail(&hand->item, &ioctl_list); - up_write(&ioctl_list_sem); - - return rc; -} -EXPORT_SYMBOL(libcfs_register_ioctl); - -int libcfs_deregister_ioctl(struct libcfs_ioctl_handler *hand) -{ - int rc = 0; - - down_write(&ioctl_list_sem); - if (list_empty(&hand->item)) - rc = -ENOENT; - else - list_del_init(&hand->item); - up_write(&ioctl_list_sem); - - return rc; -} -EXPORT_SYMBOL(libcfs_deregister_ioctl); +BLOCKING_NOTIFIER_HEAD(libcfs_ioctl_list); +EXPORT_SYMBOL(libcfs_ioctl_list); static inline size_t libcfs_ioctl_packlen(struct libcfs_ioctl_data *data) { @@ -268,24 +238,18 @@ static int libcfs_ioctl(unsigned long cmd, void __user *uparam) libcfs_debug_mark_buffer(data->ioc_inlbuf1); break; - default: { - struct libcfs_ioctl_handler *hand; - - err = -EINVAL; - down_read(&ioctl_list_sem); - list_for_each_entry(hand, &ioctl_list, item) { - err = hand->handle_ioctl(cmd, hdr); - if (err == -EINVAL) - continue; - - if (!err) { - if (copy_to_user(uparam, hdr, hdr->ioc_len)) - err = -EFAULT; - } - break; - } - up_read(&ioctl_list_sem); - break; } + default: + err = blocking_notifier_call_chain(&libcfs_ioctl_list, + cmd, hdr); + if (!(err & NOTIFY_STOP_MASK)) + /* No-one claimed the ioctl */ + err = -EINVAL; + else + err = notifier_to_errno(err); + if (!err) + if (copy_to_user(uparam, hdr, hdr->ioc_len)) + err = -EFAULT; + break; } out: kvfree(hdr); diff --git a/drivers/staging/lustre/lnet/lnet/module.c b/drivers/staging/lustre/lnet/lnet/module.c index f6e912e79ca7..9d06664f0c17 100644 --- a/drivers/staging/lustre/lnet/lnet/module.c +++ b/drivers/staging/lustre/lnet/lnet/module.c @@ -136,30 +136,37 @@ out_unlock: } static int -lnet_ioctl(unsigned int cmd, struct libcfs_ioctl_hdr *hdr) +lnet_ioctl(struct notifier_block *nb, + unsigned long cmd, void *vdata) { int rc; + struct libcfs_ioctl_hdr *hdr = vdata; switch (cmd) { case IOC_LIBCFS_CONFIGURE: { struct libcfs_ioctl_data *data = (struct libcfs_ioctl_data *)hdr; - if (data->ioc_hdr.ioc_len < sizeof(*data)) - return -EINVAL; - - the_lnet.ln_nis_from_mod_params = data->ioc_flags; - return lnet_configure(NULL); + if (data->ioc_hdr.ioc_len < sizeof(*data)) { + rc = -EINVAL; + } else { + the_lnet.ln_nis_from_mod_params = data->ioc_flags; + rc = lnet_configure(NULL); + } + break; } case IOC_LIBCFS_UNCONFIGURE: - return lnet_unconfigure(); + rc = lnet_unconfigure(); + break; case IOC_LIBCFS_ADD_NET: - return lnet_dyn_configure(hdr); + rc = lnet_dyn_configure(hdr); + break; case IOC_LIBCFS_DEL_NET: - return lnet_dyn_unconfigure(hdr); + rc = lnet_dyn_unconfigure(hdr); + break; default: /* @@ -172,11 +179,14 @@ lnet_ioctl(unsigned int cmd, struct libcfs_ioctl_hdr *hdr) rc = LNetCtl(cmd, hdr); LNetNIFini(); } - return rc; + break; } + return notifier_from_ioctl_errno(rc); } -static DECLARE_IOCTL_HANDLER(lnet_ioctl_handler, lnet_ioctl); +static struct notifier_block lnet_ioctl_handler = { + .notifier_call = lnet_ioctl, +}; static int __init lnet_init(void) { @@ -194,7 +204,8 @@ static int __init lnet_init(void) return rc; } - rc = libcfs_register_ioctl(&lnet_ioctl_handler); + rc = blocking_notifier_chain_register(&libcfs_ioctl_list, + &lnet_ioctl_handler); LASSERT(!rc); if (config_on_load) { @@ -212,7 +223,8 @@ static void __exit lnet_exit(void) { int rc; - rc = libcfs_deregister_ioctl(&lnet_ioctl_handler); + rc = blocking_notifier_chain_unregister(&libcfs_ioctl_list, + &lnet_ioctl_handler); LASSERT(!rc); lnet_lib_exit(); diff --git a/drivers/staging/lustre/lnet/selftest/conctl.c b/drivers/staging/lustre/lnet/selftest/conctl.c index a2d8092bdeb7..f22b01e390d3 100644 --- a/drivers/staging/lustre/lnet/selftest/conctl.c +++ b/drivers/staging/lustre/lnet/selftest/conctl.c @@ -680,32 +680,34 @@ out: } int -lstcon_ioctl_entry(unsigned int cmd, struct libcfs_ioctl_hdr *hdr) +lstcon_ioctl_entry(struct notifier_block *nb, + unsigned long cmd, void *vdata) { - char *buf; + struct libcfs_ioctl_hdr *hdr = vdata; + char *buf = NULL; struct libcfs_ioctl_data *data; int opc; - int rc; + int rc = -EINVAL; if (cmd != IOC_LIBCFS_LNETST) - return -EINVAL; + goto err; data = container_of(hdr, struct libcfs_ioctl_data, ioc_hdr); opc = data->ioc_u32[0]; if (data->ioc_plen1 > PAGE_SIZE) - return -EINVAL; + goto err; buf = kmalloc(data->ioc_plen1, GFP_KERNEL); + rc = -ENOMEM; if (!buf) - return -ENOMEM; + goto err; /* copy in parameter */ - if (copy_from_user(buf, data->ioc_pbuf1, data->ioc_plen1)) { - kfree(buf); - return -EFAULT; - } + rc = -EFAULT; + if (copy_from_user(buf, data->ioc_pbuf1, data->ioc_plen1)) + goto err; mutex_lock(&console_session.ses_mutex); @@ -785,6 +787,7 @@ lstcon_ioctl_entry(unsigned int cmd, struct libcfs_ioctl_hdr *hdr) break; default: rc = -EINVAL; + goto out; } if (copy_to_user(data->ioc_pbuf2, &console_session.ses_trans_stat, @@ -792,8 +795,8 @@ lstcon_ioctl_entry(unsigned int cmd, struct libcfs_ioctl_hdr *hdr) rc = -EFAULT; out: mutex_unlock(&console_session.ses_mutex); - +err: kfree(buf); - return rc; + return notifier_from_ioctl_errno(rc); } diff --git a/drivers/staging/lustre/lnet/selftest/console.c b/drivers/staging/lustre/lnet/selftest/console.c index 1889f1e86473..9fd6013354c6 100644 --- a/drivers/staging/lustre/lnet/selftest/console.c +++ b/drivers/staging/lustre/lnet/selftest/console.c @@ -1996,7 +1996,9 @@ static void lstcon_init_acceptor_service(void) lstcon_acceptor_service.sv_wi_total = SFW_FRWK_WI_MAX; } -static DECLARE_IOCTL_HANDLER(lstcon_ioctl_handler, lstcon_ioctl_entry); +static struct notifier_block lstcon_ioctl_handler = { + .notifier_call = lstcon_ioctl_entry, +}; /* initialize console */ int @@ -2048,7 +2050,8 @@ lstcon_console_init(void) goto out; } - rc = libcfs_register_ioctl(&lstcon_ioctl_handler); + rc = blocking_notifier_chain_register(&libcfs_ioctl_list, + &lstcon_ioctl_handler); if (!rc) { lstcon_rpc_module_init(); @@ -2071,7 +2074,8 @@ lstcon_console_fini(void) { int i; - libcfs_deregister_ioctl(&lstcon_ioctl_handler); + blocking_notifier_chain_unregister(&libcfs_ioctl_list, + &lstcon_ioctl_handler); mutex_lock(&console_session.ses_mutex); diff --git a/drivers/staging/lustre/lnet/selftest/console.h b/drivers/staging/lustre/lnet/selftest/console.h index 3933ed4cca93..d65b8d942bac 100644 --- a/drivers/staging/lustre/lnet/selftest/console.h +++ b/drivers/staging/lustre/lnet/selftest/console.h @@ -187,7 +187,8 @@ lstcon_id2hash(struct lnet_process_id id, struct list_head *hash) return &hash[idx]; } -int lstcon_ioctl_entry(unsigned int cmd, struct libcfs_ioctl_hdr *hdr); +int lstcon_ioctl_entry(struct notifier_block *nb, + unsigned long cmd, void *vdata); int lstcon_console_init(void); int lstcon_console_fini(void); int lstcon_session_match(struct lst_sid sid); -- 2.39.5