From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4904exOcP/3OvSpZrcAZfhtMI8hOM7jsWOTqZa6X/Yssc8SUc6ZGiXz5PZ+YYl8y9XnfBT/ ARC-Seal: i=1; a=rsa-sha256; t=1522436391; cv=none; d=google.com; s=arc-20160816; b=IjBwKnUSg4siqb60ADjovybLcQ8k3tLnnoY3EfAAOadpeRi3FjDFKRxkwfRNM8KFrR HR8MbW2JsfxONz/9agIAMJtCPt+3aEew+OdsFprBgeDAADyq2KvTR0dloyzJQ1eH1mMc p4qDPr6vf7lrvWK0SF7nOcg5+5WovN9k56sVczCBaZIDq9wZkVE1Bo3w8QAJ9x/F5vFR BsqsOKdnN1g554Qd+pHHMXP0M/OvjTihJ5Mu3uS2W7jCbD/RhpyZvcK1O1G+GYuUmftf m1wjo85GRImgGJtLdXmcky+1M7vs9A4xcSSfSn5IWr7ibjBObVhXqajjQV9gcw/lF/tl nDOA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:message-id:in-reply-to:subject :cc:to:from:date:dkim-signature:arc-authentication-results; bh=bJWyxssrJxA6wwFXGDRjE6V+JRrYOhQGzgG+fVgiQ9o=; b=IeXtQzNNAXRbIJqX8Y7blADVQJp1lu/sNmpWxtH5SL7PxtLUv661j9CwROnCKCdw3f AxJdRWNyy6J44iPG0oLpdsnqllFfi6AnJ4KQZMtRGV2PqLBhTZ+lFDI+gLWHn4ik5J6d WH7o+0qMKtMrAmnqVoFljbyb3XLHVAFH7MTbuANqEsM8aR/NOcWXa6eQX7woZuk2hQkI 6MTXQceHT6qfYoVyqlYvWB8QFmLUSf9lGJBKXbhUi9dcrKhsP9wqfAN2nVjdJn5LRhBo uaLlh4JxjFs6sup20l/6+Q4k2HgXjVJk2iAF5Da6iKmlMAWHydD29D8lNgnX49Qt2tau QB1A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=MHspxpYA; spf=pass (google.com: best guess record for domain of jsimmons@infradead.org designates 2001:8b0:10b:1236::1 as permitted sender) smtp.mailfrom=jsimmons@infradead.org Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=casper.20170209 header.b=MHspxpYA; spf=pass (google.com: best guess record for domain of jsimmons@infradead.org designates 2001:8b0:10b:1236::1 as permitted sender) smtp.mailfrom=jsimmons@infradead.org Date: Fri, 30 Mar 2018 19:59:46 +0100 (BST) From: James Simmons To: NeilBrown cc: Oleg Drokin , Greg Kroah-Hartman , Andreas Dilger , Linux Kernel Mailing List , Lustre Development List Subject: Re: [PATCH 08/17] staging: lustre: add container_of_safe() In-Reply-To: <152229760847.27689.4969508646445147289.stgit@noble> Message-ID: References: <152229732768.27689.4800156943561963977.stgit@noble> <152229760847.27689.4969508646445147289.stgit@noble> User-Agent: Alpine 2.21 (LFD 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20180330_195946_585405_27399146 X-CRM114-Status: GOOD ( 27.09 ) X-Spam-Score: -0.0 (/) X-Spam-Report: SpamAssassin version 3.4.1 on casper.infradead.org summary: Content analysis details: (-0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 NO_RELAYS Informational: message was not relayed via SMTP X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1596244818660571302?= X-GMAIL-MSGID: =?utf-8?q?1596390261481713475?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: > Luster has a container_of0() function which is similar to > container_of() but passes an IS_ERR_OR_NULL() pointer through > unchanged. > This could be generally useful: bcache at last has a similar function. > > Naming is hard, but the precedent set by hlist_entry_safe() suggests > a _safe suffix might be most consistent. > > So add container_of_safe() to kernel.h, and replace all occurrences of > container_of0() with one of > - list_first_entry, list_next_entry, when that is a better fit, > - container_of(), when the pointer is used as a validpointer in > surrounding code, > - container_of_safe() when there is no obviously better alternative. It's nice to see this become part of the kernel proper Reviewed-by: James Simmons > Signed-off-by: NeilBrown > --- > .../staging/lustre/include/linux/libcfs/libcfs.h | 11 ----------- > drivers/staging/lustre/lustre/include/cl_object.h | 10 +++++----- > drivers/staging/lustre/lustre/include/lu_object.h | 6 +++--- > drivers/staging/lustre/lustre/llite/llite_nfs.c | 2 +- > drivers/staging/lustre/lustre/llite/vvp_internal.h | 8 ++++---- > drivers/staging/lustre/lustre/lmv/lmv_internal.h | 2 +- > .../staging/lustre/lustre/lov/lov_cl_internal.h | 18 +++++++++--------- > drivers/staging/lustre/lustre/lov/lov_internal.h | 2 +- > drivers/staging/lustre/lustre/obdclass/lu_object.c | 8 ++++---- > .../staging/lustre/lustre/obdecho/echo_client.c | 2 +- > .../staging/lustre/lustre/osc/osc_cl_internal.h | 10 +++++----- > drivers/staging/lustre/lustre/osc/osc_internal.h | 2 +- > drivers/staging/lustre/lustre/osc/osc_io.c | 2 +- > drivers/staging/lustre/lustre/osc/osc_object.c | 2 +- > include/linux/kernel.h | 16 ++++++++++++++++ > 15 files changed, 53 insertions(+), 48 deletions(-) > > diff --git a/drivers/staging/lustre/include/linux/libcfs/libcfs.h b/drivers/staging/lustre/include/linux/libcfs/libcfs.h > index 392793582956..3b751c436b3d 100644 > --- a/drivers/staging/lustre/include/linux/libcfs/libcfs.h > +++ b/drivers/staging/lustre/include/linux/libcfs/libcfs.h > @@ -99,17 +99,6 @@ int libcfs_ioctl_getdata(struct libcfs_ioctl_hdr **hdr_pp, > int libcfs_ioctl_data_adjust(struct libcfs_ioctl_data *data); > int libcfs_ioctl(unsigned long cmd, void __user *arg); > > -/* container_of depends on "likely" which is defined in libcfs_private.h */ > -static inline void *__container_of(void *ptr, unsigned long shift) > -{ > - if (IS_ERR_OR_NULL(ptr)) > - return ptr; > - return (char *)ptr - shift; > -} > - > -#define container_of0(ptr, type, member) \ > - ((type *)__container_of((void *)(ptr), offsetof(type, member))) > - > #define _LIBCFS_H > > extern struct miscdevice libcfs_dev; > diff --git a/drivers/staging/lustre/lustre/include/cl_object.h b/drivers/staging/lustre/lustre/include/cl_object.h > index 341a145c3331..6f7b991be809 100644 > --- a/drivers/staging/lustre/lustre/include/cl_object.h > +++ b/drivers/staging/lustre/lustre/include/cl_object.h > @@ -1941,7 +1941,7 @@ static inline int lu_device_is_cl(const struct lu_device *d) > static inline struct cl_device *lu2cl_dev(const struct lu_device *d) > { > LASSERT(!d || IS_ERR(d) || lu_device_is_cl(d)); > - return container_of0(d, struct cl_device, cd_lu_dev); > + return container_of_safe(d, struct cl_device, cd_lu_dev); > } > > static inline struct lu_device *cl2lu_dev(struct cl_device *d) > @@ -1952,13 +1952,13 @@ static inline struct lu_device *cl2lu_dev(struct cl_device *d) > static inline struct cl_object *lu2cl(const struct lu_object *o) > { > LASSERT(!o || IS_ERR(o) || lu_device_is_cl(o->lo_dev)); > - return container_of0(o, struct cl_object, co_lu); > + return container_of_safe(o, struct cl_object, co_lu); > } > > static inline const struct cl_object_conf * > lu2cl_conf(const struct lu_object_conf *conf) > { > - return container_of0(conf, struct cl_object_conf, coc_lu); > + return container_of_safe(conf, struct cl_object_conf, coc_lu); > } > > static inline struct cl_object *cl_object_next(const struct cl_object *obj) > @@ -1969,12 +1969,12 @@ static inline struct cl_object *cl_object_next(const struct cl_object *obj) > static inline struct cl_device *cl_object_device(const struct cl_object *o) > { > LASSERT(!o || IS_ERR(o) || lu_device_is_cl(o->co_lu.lo_dev)); > - return container_of0(o->co_lu.lo_dev, struct cl_device, cd_lu_dev); > + return container_of_safe(o->co_lu.lo_dev, struct cl_device, cd_lu_dev); > } > > static inline struct cl_object_header *luh2coh(const struct lu_object_header *h) > { > - return container_of0(h, struct cl_object_header, coh_lu); > + return container_of_safe(h, struct cl_object_header, coh_lu); > } > > static inline struct cl_site *cl_object_site(const struct cl_object *obj) > diff --git a/drivers/staging/lustre/lustre/include/lu_object.h b/drivers/staging/lustre/lustre/include/lu_object.h > index 35c7b582f36d..c3b0ed518819 100644 > --- a/drivers/staging/lustre/lustre/include/lu_object.h > +++ b/drivers/staging/lustre/lustre/include/lu_object.h > @@ -745,15 +745,15 @@ struct lu_object *lu_object_find_slice(const struct lu_env *env, > static inline struct lu_object *lu_object_top(struct lu_object_header *h) > { > LASSERT(!list_empty(&h->loh_layers)); > - return container_of0(h->loh_layers.next, struct lu_object, lo_linkage); > + return list_first_entry(&h->loh_layers, struct lu_object, lo_linkage); > } > > /** > * Next sub-object in the layering > */ > -static inline struct lu_object *lu_object_next(const struct lu_object *o) > +static inline const struct lu_object *lu_object_next(const struct lu_object *o) > { > - return container_of0(o->lo_linkage.next, struct lu_object, lo_linkage); > + return list_next_entry(o, lo_linkage); > } > > /** > diff --git a/drivers/staging/lustre/lustre/llite/llite_nfs.c b/drivers/staging/lustre/lustre/llite/llite_nfs.c > index a6a1d80c711a..14172688d55f 100644 > --- a/drivers/staging/lustre/lustre/llite/llite_nfs.c > +++ b/drivers/staging/lustre/lustre/llite/llite_nfs.c > @@ -223,7 +223,7 @@ static int ll_nfs_get_name_filldir(struct dir_context *ctx, const char *name, > /* It is hack to access lde_fid for comparison with lgd_fid. > * So the input 'name' must be part of the 'lu_dirent'. > */ > - struct lu_dirent *lde = container_of0(name, struct lu_dirent, lde_name); > + struct lu_dirent *lde = container_of((void*)name, struct lu_dirent, lde_name); > struct ll_getname_data *lgd = > container_of(ctx, struct ll_getname_data, ctx); > struct lu_fid fid; > diff --git a/drivers/staging/lustre/lustre/llite/vvp_internal.h b/drivers/staging/lustre/lustre/llite/vvp_internal.h > index 02ea5161d635..7d3abb43584a 100644 > --- a/drivers/staging/lustre/lustre/llite/vvp_internal.h > +++ b/drivers/staging/lustre/lustre/llite/vvp_internal.h > @@ -263,22 +263,22 @@ static inline struct lu_device *vvp2lu_dev(struct vvp_device *vdv) > > static inline struct vvp_device *lu2vvp_dev(const struct lu_device *d) > { > - return container_of0(d, struct vvp_device, vdv_cl.cd_lu_dev); > + return container_of_safe(d, struct vvp_device, vdv_cl.cd_lu_dev); > } > > static inline struct vvp_device *cl2vvp_dev(const struct cl_device *d) > { > - return container_of0(d, struct vvp_device, vdv_cl); > + return container_of_safe(d, struct vvp_device, vdv_cl); > } > > static inline struct vvp_object *cl2vvp(const struct cl_object *obj) > { > - return container_of0(obj, struct vvp_object, vob_cl); > + return container_of_safe(obj, struct vvp_object, vob_cl); > } > > static inline struct vvp_object *lu2vvp(const struct lu_object *obj) > { > - return container_of0(obj, struct vvp_object, vob_cl.co_lu); > + return container_of_safe(obj, struct vvp_object, vob_cl.co_lu); > } > > static inline struct inode *vvp_object_inode(const struct cl_object *obj) > diff --git a/drivers/staging/lustre/lustre/lmv/lmv_internal.h b/drivers/staging/lustre/lustre/lmv/lmv_internal.h > index c27c3c32188d..68a99170c424 100644 > --- a/drivers/staging/lustre/lustre/lmv/lmv_internal.h > +++ b/drivers/staging/lustre/lustre/lmv/lmv_internal.h > @@ -60,7 +60,7 @@ int lmv_revalidate_slaves(struct obd_export *exp, > > static inline struct obd_device *lmv2obd_dev(struct lmv_obd *lmv) > { > - return container_of0(lmv, struct obd_device, u.lmv); > + return container_of_safe(lmv, struct obd_device, u.lmv); > } > > static inline struct lmv_tgt_desc * > diff --git a/drivers/staging/lustre/lustre/lov/lov_cl_internal.h b/drivers/staging/lustre/lustre/lov/lov_cl_internal.h > index 1185eceaf497..2e9c75ebdda5 100644 > --- a/drivers/staging/lustre/lustre/lov/lov_cl_internal.h > +++ b/drivers/staging/lustre/lustre/lov/lov_cl_internal.h > @@ -496,7 +496,7 @@ static inline struct lu_device *lov2lu_dev(struct lov_device *lov) > static inline struct lov_device *lu2lov_dev(const struct lu_device *d) > { > LINVRNT(d->ld_type == &lov_device_type); > - return container_of0(d, struct lov_device, ld_cl.cd_lu_dev); > + return container_of(d, struct lov_device, ld_cl.cd_lu_dev); > } > > static inline struct cl_device *lovsub2cl_dev(struct lovsub_device *lovsub) > @@ -512,13 +512,13 @@ static inline struct lu_device *lovsub2lu_dev(struct lovsub_device *lovsub) > static inline struct lovsub_device *lu2lovsub_dev(const struct lu_device *d) > { > LINVRNT(d->ld_type == &lovsub_device_type); > - return container_of0(d, struct lovsub_device, acid_cl.cd_lu_dev); > + return container_of(d, struct lovsub_device, acid_cl.cd_lu_dev); > } > > static inline struct lovsub_device *cl2lovsub_dev(const struct cl_device *d) > { > LINVRNT(d->cd_lu_dev.ld_type == &lovsub_device_type); > - return container_of0(d, struct lovsub_device, acid_cl); > + return container_of(d, struct lovsub_device, acid_cl); > } > > static inline struct lu_object *lov2lu(struct lov_object *lov) > @@ -534,13 +534,13 @@ static inline struct cl_object *lov2cl(struct lov_object *lov) > static inline struct lov_object *lu2lov(const struct lu_object *obj) > { > LINVRNT(lov_is_object(obj)); > - return container_of0(obj, struct lov_object, lo_cl.co_lu); > + return container_of(obj, struct lov_object, lo_cl.co_lu); > } > > static inline struct lov_object *cl2lov(const struct cl_object *obj) > { > LINVRNT(lov_is_object(&obj->co_lu)); > - return container_of0(obj, struct lov_object, lo_cl); > + return container_of(obj, struct lov_object, lo_cl); > } > > static inline struct lu_object *lovsub2lu(struct lovsub_object *los) > @@ -556,13 +556,13 @@ static inline struct cl_object *lovsub2cl(struct lovsub_object *los) > static inline struct lovsub_object *cl2lovsub(const struct cl_object *obj) > { > LINVRNT(lovsub_is_object(&obj->co_lu)); > - return container_of0(obj, struct lovsub_object, lso_cl); > + return container_of(obj, struct lovsub_object, lso_cl); > } > > static inline struct lovsub_object *lu2lovsub(const struct lu_object *obj) > { > LINVRNT(lovsub_is_object(obj)); > - return container_of0(obj, struct lovsub_object, lso_cl.co_lu); > + return container_of(obj, struct lovsub_object, lso_cl.co_lu); > } > > static inline struct lovsub_lock * > @@ -590,14 +590,14 @@ static inline struct lov_lock *cl2lov_lock(const struct cl_lock_slice *slice) > static inline struct lov_page *cl2lov_page(const struct cl_page_slice *slice) > { > LINVRNT(lov_is_object(&slice->cpl_obj->co_lu)); > - return container_of0(slice, struct lov_page, lps_cl); > + return container_of(slice, struct lov_page, lps_cl); > } > > static inline struct lovsub_page * > cl2lovsub_page(const struct cl_page_slice *slice) > { > LINVRNT(lovsub_is_object(&slice->cpl_obj->co_lu)); > - return container_of0(slice, struct lovsub_page, lsb_cl); > + return container_of(slice, struct lovsub_page, lsb_cl); > } > > static inline struct lov_io *cl2lov_io(const struct lu_env *env, > diff --git a/drivers/staging/lustre/lustre/lov/lov_internal.h b/drivers/staging/lustre/lustre/lov/lov_internal.h > index a56d71c2dda2..27f60dd7ab9a 100644 > --- a/drivers/staging/lustre/lustre/lov/lov_internal.h > +++ b/drivers/staging/lustre/lustre/lov/lov_internal.h > @@ -277,7 +277,7 @@ static inline bool lov_oinfo_is_dummy(const struct lov_oinfo *loi) > > static inline struct obd_device *lov2obd(const struct lov_obd *lov) > { > - return container_of0(lov, struct obd_device, u.lov); > + return container_of_safe(lov, struct obd_device, u.lov); > } > > #endif > diff --git a/drivers/staging/lustre/lustre/obdclass/lu_object.c b/drivers/staging/lustre/lustre/obdclass/lu_object.c > index 8ddf23b82a2c..6db5d95d4b36 100644 > --- a/drivers/staging/lustre/lustre/obdclass/lu_object.c > +++ b/drivers/staging/lustre/lustre/obdclass/lu_object.c > @@ -319,7 +319,7 @@ static void lu_object_free(const struct lu_env *env, struct lu_object *o) > * lives as long as possible and ->loo_object_free() methods > * can look at its contents. > */ > - o = container_of0(splice.prev, struct lu_object, lo_linkage); > + o = container_of(splice.prev, struct lu_object, lo_linkage); > list_del_init(&o->lo_linkage); > o->lo_ops->loo_object_free(env, o); > } > @@ -404,8 +404,8 @@ int lu_site_purge_objects(const struct lu_env *env, struct lu_site *s, > * races due to the reasons described in lu_object_put(). > */ > while (!list_empty(&dispose)) { > - h = container_of0(dispose.next, > - struct lu_object_header, loh_lru); > + h = container_of(dispose.next, > + struct lu_object_header, loh_lru); > list_del_init(&h->loh_lru); > lu_object_free(env, lu_object_top(h)); > lprocfs_counter_incr(s->ls_stats, LU_SS_LRU_PURGED); > @@ -579,7 +579,7 @@ static struct lu_object *htable_lookup(struct lu_site *s, > return ERR_PTR(-ENOENT); > } > > - h = container_of0(hnode, struct lu_object_header, loh_hash); > + h = container_of(hnode, struct lu_object_header, loh_hash); > if (likely(!lu_object_is_dying(h))) { > cfs_hash_get(s->ls_obj_hash, hnode); > lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_HIT); > diff --git a/drivers/staging/lustre/lustre/obdecho/echo_client.c b/drivers/staging/lustre/lustre/obdecho/echo_client.c > index 99a76db51ae0..767067b61109 100644 > --- a/drivers/staging/lustre/lustre/obdecho/echo_client.c > +++ b/drivers/staging/lustre/lustre/obdecho/echo_client.c > @@ -99,7 +99,7 @@ static int echo_client_cleanup(struct obd_device *obddev); > */ > static inline struct echo_device *cl2echo_dev(const struct cl_device *dev) > { > - return container_of0(dev, struct echo_device, ed_cl); > + return container_of_safe(dev, struct echo_device, ed_cl); > } > > static inline struct cl_device *echo_dev2cl(struct echo_device *d) > diff --git a/drivers/staging/lustre/lustre/osc/osc_cl_internal.h b/drivers/staging/lustre/lustre/osc/osc_cl_internal.h > index 1449013722f6..dc25dd12d7d5 100644 > --- a/drivers/staging/lustre/lustre/osc/osc_cl_internal.h > +++ b/drivers/staging/lustre/lustre/osc/osc_cl_internal.h > @@ -460,7 +460,7 @@ static inline int osc_is_object(const struct lu_object *obj) > static inline struct osc_device *lu2osc_dev(const struct lu_device *d) > { > LINVRNT(d->ld_type == &osc_device_type); > - return container_of0(d, struct osc_device, od_cl.cd_lu_dev); > + return container_of(d, struct osc_device, od_cl.cd_lu_dev); > } > > static inline struct obd_export *osc_export(const struct osc_object *obj) > @@ -476,7 +476,7 @@ static inline struct client_obd *osc_cli(const struct osc_object *obj) > static inline struct osc_object *cl2osc(const struct cl_object *obj) > { > LINVRNT(osc_is_object(&obj->co_lu)); > - return container_of0(obj, struct osc_object, oo_cl); > + return container_of(obj, struct osc_object, oo_cl); > } > > static inline struct cl_object *osc2cl(const struct osc_object *obj) > @@ -509,12 +509,12 @@ static inline enum cl_lock_mode osc_ldlm2cl_lock(enum ldlm_mode mode) > static inline struct osc_page *cl2osc_page(const struct cl_page_slice *slice) > { > LINVRNT(osc_is_object(&slice->cpl_obj->co_lu)); > - return container_of0(slice, struct osc_page, ops_cl); > + return container_of(slice, struct osc_page, ops_cl); > } > > static inline struct osc_page *oap2osc(struct osc_async_page *oap) > { > - return container_of0(oap, struct osc_page, ops_oap); > + return container_of_safe(oap, struct osc_page, ops_oap); > } > > static inline pgoff_t osc_index(struct osc_page *opg) > @@ -545,7 +545,7 @@ osc_cl_page_osc(struct cl_page *page, struct osc_object *osc) > static inline struct osc_lock *cl2osc_lock(const struct cl_lock_slice *slice) > { > LINVRNT(osc_is_object(&slice->cls_obj->co_lu)); > - return container_of0(slice, struct osc_lock, ols_cl); > + return container_of(slice, struct osc_lock, ols_cl); > } > > static inline struct osc_lock *osc_lock_at(const struct cl_lock *lock) > diff --git a/drivers/staging/lustre/lustre/osc/osc_internal.h b/drivers/staging/lustre/lustre/osc/osc_internal.h > index 32db150fd42e..be8c7829b3de 100644 > --- a/drivers/staging/lustre/lustre/osc/osc_internal.h > +++ b/drivers/staging/lustre/lustre/osc/osc_internal.h > @@ -180,7 +180,7 @@ struct osc_device { > > static inline struct osc_device *obd2osc_dev(const struct obd_device *d) > { > - return container_of0(d->obd_lu_dev, struct osc_device, od_cl.cd_lu_dev); > + return container_of_safe(d->obd_lu_dev, struct osc_device, od_cl.cd_lu_dev); > } > > extern struct lu_kmem_descr osc_caches[]; > diff --git a/drivers/staging/lustre/lustre/osc/osc_io.c b/drivers/staging/lustre/lustre/osc/osc_io.c > index 76743faf3e6d..67734a8ed331 100644 > --- a/drivers/staging/lustre/lustre/osc/osc_io.c > +++ b/drivers/staging/lustre/lustre/osc/osc_io.c > @@ -55,7 +55,7 @@ > static struct osc_io *cl2osc_io(const struct lu_env *env, > const struct cl_io_slice *slice) > { > - struct osc_io *oio = container_of0(slice, struct osc_io, oi_cl); > + struct osc_io *oio = container_of_safe(slice, struct osc_io, oi_cl); > > LINVRNT(oio == osc_env_io(env)); > return oio; > diff --git a/drivers/staging/lustre/lustre/osc/osc_object.c b/drivers/staging/lustre/lustre/osc/osc_object.c > index 6baa8e2e00c9..9582d5a642e2 100644 > --- a/drivers/staging/lustre/lustre/osc/osc_object.c > +++ b/drivers/staging/lustre/lustre/osc/osc_object.c > @@ -58,7 +58,7 @@ static struct lu_object *osc2lu(struct osc_object *osc) > static struct osc_object *lu2osc(const struct lu_object *obj) > { > LINVRNT(osc_is_object(obj)); > - return container_of0(obj, struct osc_object, oo_cl.co_lu); > + return container_of(obj, struct osc_object, oo_cl.co_lu); > } > > /***************************************************************************** > diff --git a/include/linux/kernel.h b/include/linux/kernel.h > index 2da80e079d56..e5e991642d8f 100644 > --- a/include/linux/kernel.h > +++ b/include/linux/kernel.h > @@ -941,6 +941,22 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } > "pointer type mismatch in container_of()"); \ > ((type *)(__mptr - offsetof(type, member))); }) > > +/** > + * container_of_safe - cast a member of a structure out to the containing structure > + * @ptr: the pointer to the member. > + * @type: the type of the container struct this is embedded in. > + * @member: the name of the member within the struct. > + * > + * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged. > + */ > +#define container_of_safe(ptr, type, member) ({ \ > + void *__mptr = (void *)(ptr); \ > + BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ > + !__same_type(*(ptr), void), \ > + "pointer type mismatch in container_of()"); \ > + IS_ERR_OR_NULL(ptr) ? ERR_CAST(ptr) : \ > + ((type *)(__mptr - offsetof(type, member))); }) > + > /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ > #ifdef CONFIG_FTRACE_MCOUNT_RECORD > # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD > > > From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Simmons Date: Fri, 30 Mar 2018 19:59:46 +0100 (BST) Subject: [lustre-devel] [PATCH 08/17] staging: lustre: add container_of_safe() In-Reply-To: <152229760847.27689.4969508646445147289.stgit@noble> References: <152229732768.27689.4800156943561963977.stgit@noble> <152229760847.27689.4969508646445147289.stgit@noble> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: NeilBrown Cc: Oleg Drokin , Greg Kroah-Hartman , Andreas Dilger , Linux Kernel Mailing List , Lustre Development List > Luster has a container_of0() function which is similar to > container_of() but passes an IS_ERR_OR_NULL() pointer through > unchanged. > This could be generally useful: bcache at last has a similar function. > > Naming is hard, but the precedent set by hlist_entry_safe() suggests > a _safe suffix might be most consistent. > > So add container_of_safe() to kernel.h, and replace all occurrences of > container_of0() with one of > - list_first_entry, list_next_entry, when that is a better fit, > - container_of(), when the pointer is used as a validpointer in > surrounding code, > - container_of_safe() when there is no obviously better alternative. It's nice to see this become part of the kernel proper Reviewed-by: James Simmons > Signed-off-by: NeilBrown > --- > .../staging/lustre/include/linux/libcfs/libcfs.h | 11 ----------- > drivers/staging/lustre/lustre/include/cl_object.h | 10 +++++----- > drivers/staging/lustre/lustre/include/lu_object.h | 6 +++--- > drivers/staging/lustre/lustre/llite/llite_nfs.c | 2 +- > drivers/staging/lustre/lustre/llite/vvp_internal.h | 8 ++++---- > drivers/staging/lustre/lustre/lmv/lmv_internal.h | 2 +- > .../staging/lustre/lustre/lov/lov_cl_internal.h | 18 +++++++++--------- > drivers/staging/lustre/lustre/lov/lov_internal.h | 2 +- > drivers/staging/lustre/lustre/obdclass/lu_object.c | 8 ++++---- > .../staging/lustre/lustre/obdecho/echo_client.c | 2 +- > .../staging/lustre/lustre/osc/osc_cl_internal.h | 10 +++++----- > drivers/staging/lustre/lustre/osc/osc_internal.h | 2 +- > drivers/staging/lustre/lustre/osc/osc_io.c | 2 +- > drivers/staging/lustre/lustre/osc/osc_object.c | 2 +- > include/linux/kernel.h | 16 ++++++++++++++++ > 15 files changed, 53 insertions(+), 48 deletions(-) > > diff --git a/drivers/staging/lustre/include/linux/libcfs/libcfs.h b/drivers/staging/lustre/include/linux/libcfs/libcfs.h > index 392793582956..3b751c436b3d 100644 > --- a/drivers/staging/lustre/include/linux/libcfs/libcfs.h > +++ b/drivers/staging/lustre/include/linux/libcfs/libcfs.h > @@ -99,17 +99,6 @@ int libcfs_ioctl_getdata(struct libcfs_ioctl_hdr **hdr_pp, > int libcfs_ioctl_data_adjust(struct libcfs_ioctl_data *data); > int libcfs_ioctl(unsigned long cmd, void __user *arg); > > -/* container_of depends on "likely" which is defined in libcfs_private.h */ > -static inline void *__container_of(void *ptr, unsigned long shift) > -{ > - if (IS_ERR_OR_NULL(ptr)) > - return ptr; > - return (char *)ptr - shift; > -} > - > -#define container_of0(ptr, type, member) \ > - ((type *)__container_of((void *)(ptr), offsetof(type, member))) > - > #define _LIBCFS_H > > extern struct miscdevice libcfs_dev; > diff --git a/drivers/staging/lustre/lustre/include/cl_object.h b/drivers/staging/lustre/lustre/include/cl_object.h > index 341a145c3331..6f7b991be809 100644 > --- a/drivers/staging/lustre/lustre/include/cl_object.h > +++ b/drivers/staging/lustre/lustre/include/cl_object.h > @@ -1941,7 +1941,7 @@ static inline int lu_device_is_cl(const struct lu_device *d) > static inline struct cl_device *lu2cl_dev(const struct lu_device *d) > { > LASSERT(!d || IS_ERR(d) || lu_device_is_cl(d)); > - return container_of0(d, struct cl_device, cd_lu_dev); > + return container_of_safe(d, struct cl_device, cd_lu_dev); > } > > static inline struct lu_device *cl2lu_dev(struct cl_device *d) > @@ -1952,13 +1952,13 @@ static inline struct lu_device *cl2lu_dev(struct cl_device *d) > static inline struct cl_object *lu2cl(const struct lu_object *o) > { > LASSERT(!o || IS_ERR(o) || lu_device_is_cl(o->lo_dev)); > - return container_of0(o, struct cl_object, co_lu); > + return container_of_safe(o, struct cl_object, co_lu); > } > > static inline const struct cl_object_conf * > lu2cl_conf(const struct lu_object_conf *conf) > { > - return container_of0(conf, struct cl_object_conf, coc_lu); > + return container_of_safe(conf, struct cl_object_conf, coc_lu); > } > > static inline struct cl_object *cl_object_next(const struct cl_object *obj) > @@ -1969,12 +1969,12 @@ static inline struct cl_object *cl_object_next(const struct cl_object *obj) > static inline struct cl_device *cl_object_device(const struct cl_object *o) > { > LASSERT(!o || IS_ERR(o) || lu_device_is_cl(o->co_lu.lo_dev)); > - return container_of0(o->co_lu.lo_dev, struct cl_device, cd_lu_dev); > + return container_of_safe(o->co_lu.lo_dev, struct cl_device, cd_lu_dev); > } > > static inline struct cl_object_header *luh2coh(const struct lu_object_header *h) > { > - return container_of0(h, struct cl_object_header, coh_lu); > + return container_of_safe(h, struct cl_object_header, coh_lu); > } > > static inline struct cl_site *cl_object_site(const struct cl_object *obj) > diff --git a/drivers/staging/lustre/lustre/include/lu_object.h b/drivers/staging/lustre/lustre/include/lu_object.h > index 35c7b582f36d..c3b0ed518819 100644 > --- a/drivers/staging/lustre/lustre/include/lu_object.h > +++ b/drivers/staging/lustre/lustre/include/lu_object.h > @@ -745,15 +745,15 @@ struct lu_object *lu_object_find_slice(const struct lu_env *env, > static inline struct lu_object *lu_object_top(struct lu_object_header *h) > { > LASSERT(!list_empty(&h->loh_layers)); > - return container_of0(h->loh_layers.next, struct lu_object, lo_linkage); > + return list_first_entry(&h->loh_layers, struct lu_object, lo_linkage); > } > > /** > * Next sub-object in the layering > */ > -static inline struct lu_object *lu_object_next(const struct lu_object *o) > +static inline const struct lu_object *lu_object_next(const struct lu_object *o) > { > - return container_of0(o->lo_linkage.next, struct lu_object, lo_linkage); > + return list_next_entry(o, lo_linkage); > } > > /** > diff --git a/drivers/staging/lustre/lustre/llite/llite_nfs.c b/drivers/staging/lustre/lustre/llite/llite_nfs.c > index a6a1d80c711a..14172688d55f 100644 > --- a/drivers/staging/lustre/lustre/llite/llite_nfs.c > +++ b/drivers/staging/lustre/lustre/llite/llite_nfs.c > @@ -223,7 +223,7 @@ static int ll_nfs_get_name_filldir(struct dir_context *ctx, const char *name, > /* It is hack to access lde_fid for comparison with lgd_fid. > * So the input 'name' must be part of the 'lu_dirent'. > */ > - struct lu_dirent *lde = container_of0(name, struct lu_dirent, lde_name); > + struct lu_dirent *lde = container_of((void*)name, struct lu_dirent, lde_name); > struct ll_getname_data *lgd = > container_of(ctx, struct ll_getname_data, ctx); > struct lu_fid fid; > diff --git a/drivers/staging/lustre/lustre/llite/vvp_internal.h b/drivers/staging/lustre/lustre/llite/vvp_internal.h > index 02ea5161d635..7d3abb43584a 100644 > --- a/drivers/staging/lustre/lustre/llite/vvp_internal.h > +++ b/drivers/staging/lustre/lustre/llite/vvp_internal.h > @@ -263,22 +263,22 @@ static inline struct lu_device *vvp2lu_dev(struct vvp_device *vdv) > > static inline struct vvp_device *lu2vvp_dev(const struct lu_device *d) > { > - return container_of0(d, struct vvp_device, vdv_cl.cd_lu_dev); > + return container_of_safe(d, struct vvp_device, vdv_cl.cd_lu_dev); > } > > static inline struct vvp_device *cl2vvp_dev(const struct cl_device *d) > { > - return container_of0(d, struct vvp_device, vdv_cl); > + return container_of_safe(d, struct vvp_device, vdv_cl); > } > > static inline struct vvp_object *cl2vvp(const struct cl_object *obj) > { > - return container_of0(obj, struct vvp_object, vob_cl); > + return container_of_safe(obj, struct vvp_object, vob_cl); > } > > static inline struct vvp_object *lu2vvp(const struct lu_object *obj) > { > - return container_of0(obj, struct vvp_object, vob_cl.co_lu); > + return container_of_safe(obj, struct vvp_object, vob_cl.co_lu); > } > > static inline struct inode *vvp_object_inode(const struct cl_object *obj) > diff --git a/drivers/staging/lustre/lustre/lmv/lmv_internal.h b/drivers/staging/lustre/lustre/lmv/lmv_internal.h > index c27c3c32188d..68a99170c424 100644 > --- a/drivers/staging/lustre/lustre/lmv/lmv_internal.h > +++ b/drivers/staging/lustre/lustre/lmv/lmv_internal.h > @@ -60,7 +60,7 @@ int lmv_revalidate_slaves(struct obd_export *exp, > > static inline struct obd_device *lmv2obd_dev(struct lmv_obd *lmv) > { > - return container_of0(lmv, struct obd_device, u.lmv); > + return container_of_safe(lmv, struct obd_device, u.lmv); > } > > static inline struct lmv_tgt_desc * > diff --git a/drivers/staging/lustre/lustre/lov/lov_cl_internal.h b/drivers/staging/lustre/lustre/lov/lov_cl_internal.h > index 1185eceaf497..2e9c75ebdda5 100644 > --- a/drivers/staging/lustre/lustre/lov/lov_cl_internal.h > +++ b/drivers/staging/lustre/lustre/lov/lov_cl_internal.h > @@ -496,7 +496,7 @@ static inline struct lu_device *lov2lu_dev(struct lov_device *lov) > static inline struct lov_device *lu2lov_dev(const struct lu_device *d) > { > LINVRNT(d->ld_type == &lov_device_type); > - return container_of0(d, struct lov_device, ld_cl.cd_lu_dev); > + return container_of(d, struct lov_device, ld_cl.cd_lu_dev); > } > > static inline struct cl_device *lovsub2cl_dev(struct lovsub_device *lovsub) > @@ -512,13 +512,13 @@ static inline struct lu_device *lovsub2lu_dev(struct lovsub_device *lovsub) > static inline struct lovsub_device *lu2lovsub_dev(const struct lu_device *d) > { > LINVRNT(d->ld_type == &lovsub_device_type); > - return container_of0(d, struct lovsub_device, acid_cl.cd_lu_dev); > + return container_of(d, struct lovsub_device, acid_cl.cd_lu_dev); > } > > static inline struct lovsub_device *cl2lovsub_dev(const struct cl_device *d) > { > LINVRNT(d->cd_lu_dev.ld_type == &lovsub_device_type); > - return container_of0(d, struct lovsub_device, acid_cl); > + return container_of(d, struct lovsub_device, acid_cl); > } > > static inline struct lu_object *lov2lu(struct lov_object *lov) > @@ -534,13 +534,13 @@ static inline struct cl_object *lov2cl(struct lov_object *lov) > static inline struct lov_object *lu2lov(const struct lu_object *obj) > { > LINVRNT(lov_is_object(obj)); > - return container_of0(obj, struct lov_object, lo_cl.co_lu); > + return container_of(obj, struct lov_object, lo_cl.co_lu); > } > > static inline struct lov_object *cl2lov(const struct cl_object *obj) > { > LINVRNT(lov_is_object(&obj->co_lu)); > - return container_of0(obj, struct lov_object, lo_cl); > + return container_of(obj, struct lov_object, lo_cl); > } > > static inline struct lu_object *lovsub2lu(struct lovsub_object *los) > @@ -556,13 +556,13 @@ static inline struct cl_object *lovsub2cl(struct lovsub_object *los) > static inline struct lovsub_object *cl2lovsub(const struct cl_object *obj) > { > LINVRNT(lovsub_is_object(&obj->co_lu)); > - return container_of0(obj, struct lovsub_object, lso_cl); > + return container_of(obj, struct lovsub_object, lso_cl); > } > > static inline struct lovsub_object *lu2lovsub(const struct lu_object *obj) > { > LINVRNT(lovsub_is_object(obj)); > - return container_of0(obj, struct lovsub_object, lso_cl.co_lu); > + return container_of(obj, struct lovsub_object, lso_cl.co_lu); > } > > static inline struct lovsub_lock * > @@ -590,14 +590,14 @@ static inline struct lov_lock *cl2lov_lock(const struct cl_lock_slice *slice) > static inline struct lov_page *cl2lov_page(const struct cl_page_slice *slice) > { > LINVRNT(lov_is_object(&slice->cpl_obj->co_lu)); > - return container_of0(slice, struct lov_page, lps_cl); > + return container_of(slice, struct lov_page, lps_cl); > } > > static inline struct lovsub_page * > cl2lovsub_page(const struct cl_page_slice *slice) > { > LINVRNT(lovsub_is_object(&slice->cpl_obj->co_lu)); > - return container_of0(slice, struct lovsub_page, lsb_cl); > + return container_of(slice, struct lovsub_page, lsb_cl); > } > > static inline struct lov_io *cl2lov_io(const struct lu_env *env, > diff --git a/drivers/staging/lustre/lustre/lov/lov_internal.h b/drivers/staging/lustre/lustre/lov/lov_internal.h > index a56d71c2dda2..27f60dd7ab9a 100644 > --- a/drivers/staging/lustre/lustre/lov/lov_internal.h > +++ b/drivers/staging/lustre/lustre/lov/lov_internal.h > @@ -277,7 +277,7 @@ static inline bool lov_oinfo_is_dummy(const struct lov_oinfo *loi) > > static inline struct obd_device *lov2obd(const struct lov_obd *lov) > { > - return container_of0(lov, struct obd_device, u.lov); > + return container_of_safe(lov, struct obd_device, u.lov); > } > > #endif > diff --git a/drivers/staging/lustre/lustre/obdclass/lu_object.c b/drivers/staging/lustre/lustre/obdclass/lu_object.c > index 8ddf23b82a2c..6db5d95d4b36 100644 > --- a/drivers/staging/lustre/lustre/obdclass/lu_object.c > +++ b/drivers/staging/lustre/lustre/obdclass/lu_object.c > @@ -319,7 +319,7 @@ static void lu_object_free(const struct lu_env *env, struct lu_object *o) > * lives as long as possible and ->loo_object_free() methods > * can look at its contents. > */ > - o = container_of0(splice.prev, struct lu_object, lo_linkage); > + o = container_of(splice.prev, struct lu_object, lo_linkage); > list_del_init(&o->lo_linkage); > o->lo_ops->loo_object_free(env, o); > } > @@ -404,8 +404,8 @@ int lu_site_purge_objects(const struct lu_env *env, struct lu_site *s, > * races due to the reasons described in lu_object_put(). > */ > while (!list_empty(&dispose)) { > - h = container_of0(dispose.next, > - struct lu_object_header, loh_lru); > + h = container_of(dispose.next, > + struct lu_object_header, loh_lru); > list_del_init(&h->loh_lru); > lu_object_free(env, lu_object_top(h)); > lprocfs_counter_incr(s->ls_stats, LU_SS_LRU_PURGED); > @@ -579,7 +579,7 @@ static struct lu_object *htable_lookup(struct lu_site *s, > return ERR_PTR(-ENOENT); > } > > - h = container_of0(hnode, struct lu_object_header, loh_hash); > + h = container_of(hnode, struct lu_object_header, loh_hash); > if (likely(!lu_object_is_dying(h))) { > cfs_hash_get(s->ls_obj_hash, hnode); > lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_HIT); > diff --git a/drivers/staging/lustre/lustre/obdecho/echo_client.c b/drivers/staging/lustre/lustre/obdecho/echo_client.c > index 99a76db51ae0..767067b61109 100644 > --- a/drivers/staging/lustre/lustre/obdecho/echo_client.c > +++ b/drivers/staging/lustre/lustre/obdecho/echo_client.c > @@ -99,7 +99,7 @@ static int echo_client_cleanup(struct obd_device *obddev); > */ > static inline struct echo_device *cl2echo_dev(const struct cl_device *dev) > { > - return container_of0(dev, struct echo_device, ed_cl); > + return container_of_safe(dev, struct echo_device, ed_cl); > } > > static inline struct cl_device *echo_dev2cl(struct echo_device *d) > diff --git a/drivers/staging/lustre/lustre/osc/osc_cl_internal.h b/drivers/staging/lustre/lustre/osc/osc_cl_internal.h > index 1449013722f6..dc25dd12d7d5 100644 > --- a/drivers/staging/lustre/lustre/osc/osc_cl_internal.h > +++ b/drivers/staging/lustre/lustre/osc/osc_cl_internal.h > @@ -460,7 +460,7 @@ static inline int osc_is_object(const struct lu_object *obj) > static inline struct osc_device *lu2osc_dev(const struct lu_device *d) > { > LINVRNT(d->ld_type == &osc_device_type); > - return container_of0(d, struct osc_device, od_cl.cd_lu_dev); > + return container_of(d, struct osc_device, od_cl.cd_lu_dev); > } > > static inline struct obd_export *osc_export(const struct osc_object *obj) > @@ -476,7 +476,7 @@ static inline struct client_obd *osc_cli(const struct osc_object *obj) > static inline struct osc_object *cl2osc(const struct cl_object *obj) > { > LINVRNT(osc_is_object(&obj->co_lu)); > - return container_of0(obj, struct osc_object, oo_cl); > + return container_of(obj, struct osc_object, oo_cl); > } > > static inline struct cl_object *osc2cl(const struct osc_object *obj) > @@ -509,12 +509,12 @@ static inline enum cl_lock_mode osc_ldlm2cl_lock(enum ldlm_mode mode) > static inline struct osc_page *cl2osc_page(const struct cl_page_slice *slice) > { > LINVRNT(osc_is_object(&slice->cpl_obj->co_lu)); > - return container_of0(slice, struct osc_page, ops_cl); > + return container_of(slice, struct osc_page, ops_cl); > } > > static inline struct osc_page *oap2osc(struct osc_async_page *oap) > { > - return container_of0(oap, struct osc_page, ops_oap); > + return container_of_safe(oap, struct osc_page, ops_oap); > } > > static inline pgoff_t osc_index(struct osc_page *opg) > @@ -545,7 +545,7 @@ osc_cl_page_osc(struct cl_page *page, struct osc_object *osc) > static inline struct osc_lock *cl2osc_lock(const struct cl_lock_slice *slice) > { > LINVRNT(osc_is_object(&slice->cls_obj->co_lu)); > - return container_of0(slice, struct osc_lock, ols_cl); > + return container_of(slice, struct osc_lock, ols_cl); > } > > static inline struct osc_lock *osc_lock_at(const struct cl_lock *lock) > diff --git a/drivers/staging/lustre/lustre/osc/osc_internal.h b/drivers/staging/lustre/lustre/osc/osc_internal.h > index 32db150fd42e..be8c7829b3de 100644 > --- a/drivers/staging/lustre/lustre/osc/osc_internal.h > +++ b/drivers/staging/lustre/lustre/osc/osc_internal.h > @@ -180,7 +180,7 @@ struct osc_device { > > static inline struct osc_device *obd2osc_dev(const struct obd_device *d) > { > - return container_of0(d->obd_lu_dev, struct osc_device, od_cl.cd_lu_dev); > + return container_of_safe(d->obd_lu_dev, struct osc_device, od_cl.cd_lu_dev); > } > > extern struct lu_kmem_descr osc_caches[]; > diff --git a/drivers/staging/lustre/lustre/osc/osc_io.c b/drivers/staging/lustre/lustre/osc/osc_io.c > index 76743faf3e6d..67734a8ed331 100644 > --- a/drivers/staging/lustre/lustre/osc/osc_io.c > +++ b/drivers/staging/lustre/lustre/osc/osc_io.c > @@ -55,7 +55,7 @@ > static struct osc_io *cl2osc_io(const struct lu_env *env, > const struct cl_io_slice *slice) > { > - struct osc_io *oio = container_of0(slice, struct osc_io, oi_cl); > + struct osc_io *oio = container_of_safe(slice, struct osc_io, oi_cl); > > LINVRNT(oio == osc_env_io(env)); > return oio; > diff --git a/drivers/staging/lustre/lustre/osc/osc_object.c b/drivers/staging/lustre/lustre/osc/osc_object.c > index 6baa8e2e00c9..9582d5a642e2 100644 > --- a/drivers/staging/lustre/lustre/osc/osc_object.c > +++ b/drivers/staging/lustre/lustre/osc/osc_object.c > @@ -58,7 +58,7 @@ static struct lu_object *osc2lu(struct osc_object *osc) > static struct osc_object *lu2osc(const struct lu_object *obj) > { > LINVRNT(osc_is_object(obj)); > - return container_of0(obj, struct osc_object, oo_cl.co_lu); > + return container_of(obj, struct osc_object, oo_cl.co_lu); > } > > /***************************************************************************** > diff --git a/include/linux/kernel.h b/include/linux/kernel.h > index 2da80e079d56..e5e991642d8f 100644 > --- a/include/linux/kernel.h > +++ b/include/linux/kernel.h > @@ -941,6 +941,22 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } > "pointer type mismatch in container_of()"); \ > ((type *)(__mptr - offsetof(type, member))); }) > > +/** > + * container_of_safe - cast a member of a structure out to the containing structure > + * @ptr: the pointer to the member. > + * @type: the type of the container struct this is embedded in. > + * @member: the name of the member within the struct. > + * > + * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged. > + */ > +#define container_of_safe(ptr, type, member) ({ \ > + void *__mptr = (void *)(ptr); \ > + BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ > + !__same_type(*(ptr), void), \ > + "pointer type mismatch in container_of()"); \ > + IS_ERR_OR_NULL(ptr) ? ERR_CAST(ptr) : \ > + ((type *)(__mptr - offsetof(type, member))); }) > + > /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ > #ifdef CONFIG_FTRACE_MCOUNT_RECORD > # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD > > >