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d="scan'208";a="114917444" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 24 Sep 2021 21:10:18 +0800 Received: from G08CNEXMBPEKD05.g08.fujitsu.local (unknown [10.167.33.204]) by cn.fujitsu.com (Postfix) with ESMTP id A4D654D0DC7A; Fri, 24 Sep 2021 21:10:14 +0800 (CST) Received: from G08CNEXCHPEKD09.g08.fujitsu.local (10.167.33.85) by G08CNEXMBPEKD05.g08.fujitsu.local (10.167.33.204) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Fri, 24 Sep 2021 21:10:16 +0800 Received: from irides.mr.mr.mr (10.167.225.141) by G08CNEXCHPEKD09.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.23 via Frontend Transport; Fri, 24 Sep 2021 21:10:13 +0800 From: Shiyang Ruan To: , , , , CC: , , , , Subject: [PATCH v7 2/8] dax: Introduce holder for dax_device Date: Fri, 24 Sep 2021 21:09:53 +0800 Message-ID: <20210924130959.2695749-3-ruansy.fnst@fujitsu.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210924130959.2695749-1-ruansy.fnst@fujitsu.com> References: <20210924130959.2695749-1-ruansy.fnst@fujitsu.com> MIME-Version: 1.0 X-yoursite-MailScanner-ID: A4D654D0DC7A.A1C90 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@fujitsu.com X-Rspamd-Queue-Id: 7483010000B9 X-Stat-Signature: eqqzg8sx3zztrmimd98t4ri1jjgn4ddj Authentication-Results: imf07.hostedemail.com; dkim=none; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=fujitsu.com (policy=none); spf=none (imf07.hostedemail.com: domain of ruansy.fnst@fujitsu.com has no SPF policy when checking 183.91.158.132) smtp.mailfrom=ruansy.fnst@fujitsu.com X-Rspamd-Server: rspam06 X-HE-Tag: 1632489021-579579 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 | 59 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/dax.h | 29 ++++++++++++++++++++++ 2 files changed, 88 insertions(+) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 48ce86501d93..7d4a11dcba90 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -23,7 +23,10 @@ * @cdev: optional character interface for "device dax" * @host: optional name for lookups where the device path is not available * @private: dax driver private data + * @holder_data: holder of a dax_device: could be filesystem or mapped device * @flags: state and boolean properties + * @ops: operations for dax_device + * @holder_ops: operations for the inner holder */ struct dax_device { struct hlist_node list; @@ -31,8 +34,10 @@ struct dax_device { struct cdev cdev; const char *host; void *private; + void *holder_data; unsigned long flags; const struct dax_operations *ops; + const struct dax_holder_operations *holder_ops; }; static dev_t dax_devt; @@ -374,6 +379,29 @@ 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, int flags) +{ + int rc; + + dax_read_lock(); + if (!dax_alive(dax_dev)) { + rc = -ENXIO; + goto out; + } + + if (!dax_dev->holder_data) { + rc = -EOPNOTSUPP; + goto out; + } + + rc = dax_dev->holder_ops->notify_failure(dax_dev, offset, size, flags); +out: + dax_read_unlock(); + 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) @@ -618,6 +646,37 @@ 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) +{ + dax_write_lock(); + if (!dax_alive(dax_dev)) { + dax_write_unlock(); + return; + } + + dax_dev->holder_data = holder; + dax_dev->holder_ops = ops; + dax_write_unlock(); +} +EXPORT_SYMBOL_GPL(dax_set_holder); + +void *dax_get_holder(struct dax_device *dax_dev) +{ + void *holder; + + dax_read_lock(); + if (!dax_alive(dax_dev)) { + dax_read_unlock(); + return NULL; + } + + holder = dax_dev->holder_data; + dax_read_unlock(); + return holder; +} +EXPORT_SYMBOL_GPL(dax_get_holder); + /** * inode_dax: convert a public inode into its dax_dev * @inode: An inode with i_cdev pointing to a dax_dev diff --git a/include/linux/dax.h b/include/linux/dax.h index 097b3304f9b9..d273d59723cd 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -38,9 +38,24 @@ struct dax_operations { int (*zero_page_range)(struct dax_device *, pgoff_t, size_t); }; +struct dax_holder_operations { + /* + * notify_failure - notify memory failure into inner holder device + * @dax_dev: the dax device which contains the holder + * @offset: offset on this dax device where memory failure occurs + * @size: length of this memory failure event + * @flags: action flags for memory failure handler + */ + int (*notify_failure)(struct dax_device *dax_dev, loff_t offset, + size_t size, int flags); +}; + extern struct attribute_group dax_attribute_group; #if IS_ENABLED(CONFIG_DAX) +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); @@ -70,6 +85,18 @@ static inline bool daxdev_mapping_supported(struct vm_area_struct *vma, return dax_synchronous(dax_dev); } #else +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) { @@ -198,6 +225,8 @@ 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, int flags); 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,