From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from heian.cn.fujitsu.com (mail.cn.fujitsu.com [183.91.158.132]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 9FCF16D11 for ; Mon, 28 Jun 2021 00:03:10 +0000 (UTC) IronPort-HdrOrdr: =?us-ascii?q?A9a23=3AWJU4YKyumXfXlyQA26UeKrPwyr1zdoMgy1kn?= =?us-ascii?q?xilNoRw8SK2lfqeV7Y0mPH7P+U4ssR4b6LO90cW7Lk80sKQFhbX5Xo3SOjUO2l?= =?us-ascii?q?HYTr2KhLGKq1aLdkHDH6xmpMBdmsNFaOEYY2IVsS+D2njcLz8/+qj6zImYwffZ?= =?us-ascii?q?02x2TRxnL4Vp7wJCAA6dFUFsLTM2f6YRJd6N4NZdvTq8dTAyZsS/PHMMWO/OvJ?= =?us-ascii?q?nlj5TjCCR2eiIP2U2fiy+y8r7mH1y91hcaaTlGxrAv6izkvmXCl96ej80=3D?= X-IronPort-AV: E=Sophos;i="5.83,304,1616428800"; d="scan'208";a="110256332" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 28 Jun 2021 08:03:03 +0800 Received: from G08CNEXMBPEKD04.g08.fujitsu.local (unknown [10.167.33.201]) by cn.fujitsu.com (Postfix) with ESMTP id 3E44C4D0BA6A; Mon, 28 Jun 2021 08:03:01 +0800 (CST) Received: from G08CNEXJMPEKD02.g08.fujitsu.local (10.167.33.202) by G08CNEXMBPEKD04.g08.fujitsu.local (10.167.33.201) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 28 Jun 2021 08:02:57 +0800 Received: from G08CNEXCHPEKD07.g08.fujitsu.local (10.167.33.80) by G08CNEXJMPEKD02.g08.fujitsu.local (10.167.33.202) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Mon, 28 Jun 2021 08:02:56 +0800 Received: from irides.mr.mr.mr (10.167.225.141) by G08CNEXCHPEKD07.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Mon, 28 Jun 2021 08:02:56 +0800 From: Shiyang Ruan To: , , , , , CC: , , , , , , Subject: [PATCH v5 2/9] dax: Introduce holder for dax_device Date: Mon, 28 Jun 2021 08:02:11 +0800 Message-ID: <20210628000218.387833-3-ruansy.fnst@fujitsu.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210628000218.387833-1-ruansy.fnst@fujitsu.com> References: <20210628000218.387833-1-ruansy.fnst@fujitsu.com> Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-yoursite-MailScanner-ID: 3E44C4D0BA6A.A2802 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@fujitsu.com X-Spam-Status: No To easily track filesystem from a pmem device, we introduce a holder for dax_device structure, and also its operation. This holder is used to remember who is using this dax_device: - When it is the backend of a filesystem, the holder will be the superblock of this filesystem. - When this pmem device is one of the targets in a mapped device, the holder will be this mapped device. In this case, the mapped device has its own dax_device and it will follow the first rule. So that we can finally track to the filesystem we needed. The holder and holder_ops will be set when filesystem is being mounted, or an target device is being activated. Signed-off-by: Shiyang Ruan --- drivers/dax/super.c | 49 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/dax.h | 17 ++++++++++++++++ 2 files changed, 66 insertions(+) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 5fa6ae9dbc8b..22f0aa3f2e13 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -222,8 +222,11 @@ struct dax_device { struct cdev cdev; const char *host; void *private; + struct rw_semaphore holder_rwsem; + void *holder_data; unsigned long flags; const struct dax_operations *ops; + const struct dax_holder_operations *holder_ops; }; static ssize_t write_cache_show(struct device *dev, @@ -373,6 +376,24 @@ int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, } EXPORT_SYMBOL_GPL(dax_zero_page_range); +int dax_holder_notify_failure(struct dax_device *dax_dev, loff_t offset, + size_t size, void *data) +{ + int rc = -ENXIO; + if (!dax_dev) + return rc; + + if (dax_dev->holder_data) { + rc = dax_dev->holder_ops->notify_failure(dax_dev, offset, + size, data); + if (rc == -ENODEV) + rc = -ENXIO; + } else + rc = -EOPNOTSUPP; + return rc; +} +EXPORT_SYMBOL_GPL(dax_holder_notify_failure); + #ifdef CONFIG_ARCH_HAS_PMEM_API void arch_wb_cache_pmem(void *addr, size_t size); void dax_flush(struct dax_device *dax_dev, void *addr, size_t size) @@ -603,6 +624,7 @@ struct dax_device *alloc_dax(void *private, const char *__host, dax_add_host(dax_dev, host); dax_dev->ops = ops; dax_dev->private = private; + init_rwsem(&dax_dev->holder_rwsem); if (flags & DAXDEV_F_SYNC) set_dax_synchronous(dax_dev); @@ -624,6 +646,33 @@ void put_dax(struct dax_device *dax_dev) } EXPORT_SYMBOL_GPL(put_dax); +void dax_set_holder(struct dax_device *dax_dev, void *holder, + const struct dax_holder_operations *ops) +{ + if (!dax_dev) + return; + down_write(&dax_dev->holder_rwsem); + dax_dev->holder_data = holder; + dax_dev->holder_ops = ops; + up_write(&dax_dev->holder_rwsem); +} +EXPORT_SYMBOL_GPL(dax_set_holder); + +void *dax_get_holder(struct dax_device *dax_dev) +{ + void *holder_data; + + if (!dax_dev) + return NULL; + + down_read(&dax_dev->holder_rwsem); + holder_data = dax_dev->holder_data; + up_read(&dax_dev->holder_rwsem); + + return holder_data; +} +EXPORT_SYMBOL_GPL(dax_get_holder); + /** * dax_get_by_host() - temporary lookup mechanism for filesystem-dax * @host: alternate name for the device registered by a dax driver diff --git a/include/linux/dax.h b/include/linux/dax.h index b52f084aa643..6f4b5c97ceb0 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -38,10 +38,17 @@ struct dax_operations { int (*zero_page_range)(struct dax_device *, pgoff_t, size_t); }; +struct dax_holder_operations { + int (*notify_failure)(struct dax_device *, loff_t, size_t, void *); +}; + extern struct attribute_group dax_attribute_group; #if IS_ENABLED(CONFIG_DAX) struct dax_device *dax_get_by_host(const char *host); +void dax_set_holder(struct dax_device *dax_dev, void *holder, + const struct dax_holder_operations *ops); +void *dax_get_holder(struct dax_device *dax_dev); struct dax_device *alloc_dax(void *private, const char *host, const struct dax_operations *ops, unsigned long flags); void put_dax(struct dax_device *dax_dev); @@ -77,6 +84,14 @@ static inline struct dax_device *dax_get_by_host(const char *host) { return NULL; } +static inline void dax_set_holder(struct dax_device *dax_dev, void *holder, + const struct dax_holder_operations *ops) +{ +} +static inline void *dax_get_holder(struct dax_device *dax_dev) +{ + return NULL; +} static inline struct dax_device *alloc_dax(void *private, const char *host, const struct dax_operations *ops, unsigned long flags) { @@ -226,6 +241,8 @@ size_t dax_copy_to_iter(struct dax_device *dax_dev, pgoff_t pgoff, void *addr, size_t bytes, struct iov_iter *i); int dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff, size_t nr_pages); +int dax_holder_notify_failure(struct dax_device *dax_dev, loff_t offset, + size_t size, void *data); void dax_flush(struct dax_device *dax_dev, void *addr, size_t size); ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, -- 2.32.0