From patchwork Tue Jan 23 13:26:46 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 13527443 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8806560258; Tue, 23 Jan 2024 13:28:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706016489; cv=none; b=LpY/LSNzQV0wO1aZyFkoNvGKevSmA90yhjYK8iFpIlGCf/Lw0MDYTagbDu7JxF/aT6iQouoh3u8Fn5nDRdRilN04UD4+XgmG5+JRDP+NGtlASYm/TLCiemnScgjUpfDHkkC3khZmkv1X07n1eJBlLVrOQEFo6RB3j5O93g4vox0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706016489; c=relaxed/simple; bh=2xUBoCjEzVM2g6HqpxwtJhEVTkF10uVrmchKukKoXH4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Fro47k+aqRiuSl1/MNLfDaf6LikkLGHLBnsQJDPvZ0t7yEIp7uM7xh9ZmfwzKo5CW2OVt4Lv3wN7T4286mpYuaLe0L+yeyJ5SPikWdG7gl7Jtnk9LR+nsps1vgxQ/uTNWzmag2tTJP1OpbRVhaYL7LYbeJgKCCKegctjWNHifwk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=To3MOWDD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="To3MOWDD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13E4CC32782; Tue, 23 Jan 2024 13:28:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706016489; bh=2xUBoCjEzVM2g6HqpxwtJhEVTkF10uVrmchKukKoXH4=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=To3MOWDD/Zot7lLpbc7aUnn9j7eo8Z8hasco7NrTesNhvUtSDvoYexKabk8RimDe9 gFOjAO1zZqZhjK79YRX+2QGb/kcSH5juL2fsrEXGf0Nmo/3yFGZ1/OTlkOaq1gtR2+ VKcGstlKTQefXXWFe7yFQQVqPuRGOxJRNHkK6F2k0UlnvDFi8cXU2NCXmHFUWd66GU Lvr9tW0c3xIkUBTncZZk/UYqEtSKGWJz6K8/kRqnzXs2E8rT3oMq5DHGuiMvErXVQP IvEdGwR4+5QQFBGo/r/ovNGn9HVbEkxD3T0E0pWavbQJmGkvJ4kN5+IPf2nvWh0TFk LbQWQA2me0iUg== From: Christian Brauner Date: Tue, 23 Jan 2024 14:26:46 +0100 Subject: [PATCH v2 29/34] bdev: make struct bdev_handle private to the block layer Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240123-vfs-bdev-file-v2-29-adbd023e19cc@kernel.org> References: <20240123-vfs-bdev-file-v2-0-adbd023e19cc@kernel.org> In-Reply-To: <20240123-vfs-bdev-file-v2-0-adbd023e19cc@kernel.org> To: Jan Kara , Christoph Hellwig , Jens Axboe Cc: "Darrick J. Wong" , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, Christian Brauner X-Mailer: b4 0.13-dev-4e032 X-Developer-Signature: v=1; a=openpgp-sha256; l=10332; i=brauner@kernel.org; h=from:subject:message-id; bh=2xUBoCjEzVM2g6HqpxwtJhEVTkF10uVrmchKukKoXH4=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMaSu37dwp71F+qLXfByVuf16EvnGJ6+82Lw18kJX354f9 woizHmqO0pZGMS4GGTFFFkc2k3C5ZbzVGw2ytSAmcPKBDKEgYtTACZS4cbwh/fzps5XAbkLV+mm Rj75dTu7ozBp0ZG0mV5ul64Vz3qw4hQjwz53x019Jey/J54sNLnwz/dh5dcFiX86786wC1+zZmu sAjcA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Signed-off-by: Christian Brauner Reviewed-by: Christoph Hellwig --- block/bdev.c | 125 +++++++++++++++++++++++++++---------------------- block/blk.h | 12 +++-- block/fops.c | 34 ++++++-------- include/linux/blkdev.h | 7 --- include/linux/fs.h | 6 --- 5 files changed, 92 insertions(+), 92 deletions(-) diff --git a/block/bdev.c b/block/bdev.c index 1f64f213c5fa..34b9a16edb6e 100644 --- a/block/bdev.c +++ b/block/bdev.c @@ -703,6 +703,24 @@ static int blkdev_get_part(struct block_device *part, blk_mode_t mode) return ret; } +int bdev_permission(dev_t dev, blk_mode_t mode, void *holder) +{ + int ret; + + ret = devcgroup_check_permission( + DEVCG_DEV_BLOCK, MAJOR(dev), MINOR(dev), + ((mode & BLK_OPEN_READ) ? DEVCG_ACC_READ : 0) | + ((mode & BLK_OPEN_WRITE) ? DEVCG_ACC_WRITE : 0)); + if (ret) + return ret; + + /* Blocking writes requires exclusive opener */ + if (mode & BLK_OPEN_RESTRICT_WRITES && !holder) + return -EINVAL; + + return 0; +} + static void blkdev_put_part(struct block_device *part) { struct block_device *whole = bdev_whole(part); @@ -795,15 +813,15 @@ static void bdev_yield_write_access(struct block_device *bdev, blk_mode_t mode) } /** - * bdev_open_by_dev - open a block device by device number - * @dev: device number of block device to open + * bdev_open - open a block device + * @bdev: block device to open * @mode: open mode (BLK_OPEN_*) * @holder: exclusive holder identifier * @hops: holder operations + * @bdev_file: file for the block device * - * Open the block device described by device number @dev. If @holder is not - * %NULL, the block device is opened with exclusive access. Exclusive opens may - * nest for the same @holder. + * Open the block device. If @holder is not %NULL, the block device is opened + * with exclusive access. Exclusive opens may nest for the same @holder. * * Use this interface ONLY if you really do not have anything better - i.e. when * you are behind a truly sucky interface and all you are given is a device @@ -813,52 +831,29 @@ static void bdev_yield_write_access(struct block_device *bdev, blk_mode_t mode) * Might sleep. * * RETURNS: - * Handle with a reference to the block_device on success, ERR_PTR(-errno) on - * failure. + * zero on success, -errno on failure. */ -struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, - const struct blk_holder_ops *hops) +int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder, + const struct blk_holder_ops *hops, struct file *bdev_file) { struct bdev_handle *handle = kmalloc(sizeof(struct bdev_handle), GFP_KERNEL); - struct block_device *bdev; bool unblock_events = true; - struct gendisk *disk; + struct gendisk *disk = bdev->bd_disk; int ret; + handle = kmalloc(sizeof(struct bdev_handle), GFP_KERNEL); if (!handle) - return ERR_PTR(-ENOMEM); - - ret = devcgroup_check_permission(DEVCG_DEV_BLOCK, - MAJOR(dev), MINOR(dev), - ((mode & BLK_OPEN_READ) ? DEVCG_ACC_READ : 0) | - ((mode & BLK_OPEN_WRITE) ? DEVCG_ACC_WRITE : 0)); - if (ret) - goto free_handle; - - /* Blocking writes requires exclusive opener */ - if (mode & BLK_OPEN_RESTRICT_WRITES && !holder) { - ret = -EINVAL; - goto free_handle; - } - - bdev = blkdev_get_no_open(dev); - if (!bdev) { - ret = -ENXIO; - goto free_handle; - } - disk = bdev->bd_disk; + return -ENOMEM; if (holder) { mode |= BLK_OPEN_EXCL; ret = bd_prepare_to_claim(bdev, holder, hops); if (ret) - goto put_blkdev; + return ret; } else { - if (WARN_ON_ONCE(mode & BLK_OPEN_EXCL)) { - ret = -EIO; - goto put_blkdev; - } + if (WARN_ON_ONCE(mode & BLK_OPEN_EXCL)) + return -EIO; } disk_block_events(disk); @@ -902,7 +897,22 @@ struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, handle->bdev = bdev; handle->holder = holder; handle->mode = mode; - return handle; + + /* + * Preserve backwards compatibility and allow large file access + * even if userspace doesn't ask for it explicitly. Some mkfs + * binary needs it. We might want to drop this workaround + * during an unstable branch. + */ + bdev_file->f_flags |= O_LARGEFILE; + bdev_file->f_mode |= FMODE_BUF_RASYNC | FMODE_CAN_ODIRECT; + if (bdev_nowait(bdev)) + bdev_file->f_mode |= FMODE_NOWAIT; + bdev_file->f_mapping = handle->bdev->bd_inode->i_mapping; + bdev_file->f_wb_err = filemap_sample_wb_err(bdev_file->f_mapping); + bdev_file->private_data = handle; + + return 0; put_module: module_put(disk->fops->owner); abort_claiming: @@ -910,11 +920,8 @@ struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, bd_abort_claiming(bdev, holder); mutex_unlock(&disk->open_mutex); disk_unblock_events(disk); -put_blkdev: - blkdev_put_no_open(bdev); -free_handle: kfree(handle); - return ERR_PTR(ret); + return ret; } static unsigned blk_to_file_flags(blk_mode_t mode) @@ -954,29 +961,35 @@ struct file *bdev_file_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, const struct blk_holder_ops *hops) { struct file *bdev_file; - struct bdev_handle *handle; + struct block_device *bdev; unsigned int flags; + int ret; - handle = bdev_open_by_dev(dev, mode, holder, hops); - if (IS_ERR(handle)) - return ERR_CAST(handle); + ret = bdev_permission(dev, 0, holder); + if (ret) + return ERR_PTR(ret); + + bdev = blkdev_get_no_open(dev); + if (!bdev) + return ERR_PTR(-ENXIO); flags = blk_to_file_flags(mode); - bdev_file = alloc_file_pseudo_noaccount(handle->bdev->bd_inode, + bdev_file = alloc_file_pseudo_noaccount(bdev->bd_inode, blockdev_mnt, "", flags | O_LARGEFILE, &def_blk_fops); if (IS_ERR(bdev_file)) { - bdev_release(handle); + blkdev_put_no_open(bdev); return bdev_file; } - ihold(handle->bdev->bd_inode); + bdev_file->f_mode &= ~FMODE_OPENED; - bdev_file->f_mode |= FMODE_BUF_RASYNC | FMODE_CAN_ODIRECT; - if (bdev_nowait(handle->bdev)) - bdev_file->f_mode |= FMODE_NOWAIT; - - bdev_file->f_mapping = handle->bdev->bd_inode->i_mapping; - bdev_file->f_wb_err = filemap_sample_wb_err(bdev_file->f_mapping); - bdev_file->private_data = handle; + ihold(bdev->bd_inode); + ret = bdev_open(bdev, mode, holder, hops, bdev_file); + if (ret) { + fput(bdev_file); + return ERR_PTR(ret); + } + /* Now that thing is opened. */ + bdev_file->f_mode |= FMODE_OPENED; return bdev_file; } EXPORT_SYMBOL(bdev_file_open_by_dev); diff --git a/block/blk.h b/block/blk.h index c9630774767d..19b15870284f 100644 --- a/block/blk.h +++ b/block/blk.h @@ -25,6 +25,12 @@ struct blk_flush_queue { struct request *flush_rq; }; +struct bdev_handle { + struct block_device *bdev; + void *holder; + blk_mode_t mode; +}; + bool is_flush_rq(struct request *req); struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size, @@ -517,7 +523,7 @@ static inline int req_ref_read(struct request *req) } void bdev_release(struct bdev_handle *handle); -struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, - const struct blk_holder_ops *hops); - +int bdev_open(struct block_device *bdev, blk_mode_t mode, void *holder, + const struct blk_holder_ops *hops, struct file *bdev_file); +int bdev_permission(dev_t dev, blk_mode_t mode, void *holder); #endif /* BLK_INTERNAL_H */ diff --git a/block/fops.c b/block/fops.c index 0cf8cf72cdfa..81ff8c0ce32f 100644 --- a/block/fops.c +++ b/block/fops.c @@ -599,31 +599,25 @@ blk_mode_t file_to_blk_mode(struct file *file) static int blkdev_open(struct inode *inode, struct file *filp) { - struct bdev_handle *handle; + struct block_device *bdev; blk_mode_t mode; - - /* - * Preserve backwards compatibility and allow large file access - * even if userspace doesn't ask for it explicitly. Some mkfs - * binary needs it. We might want to drop this workaround - * during an unstable branch. - */ - filp->f_flags |= O_LARGEFILE; - filp->f_mode |= FMODE_BUF_RASYNC | FMODE_CAN_ODIRECT; + void *holder; + int ret; mode = file_to_blk_mode(filp); - handle = bdev_open_by_dev(inode->i_rdev, mode, - mode & BLK_OPEN_EXCL ? filp : NULL, NULL); - if (IS_ERR(handle)) - return PTR_ERR(handle); + holder = mode & BLK_OPEN_EXCL ? filp : NULL; + ret = bdev_permission(inode->i_rdev, mode, holder); + if (ret) + return ret; - if (bdev_nowait(handle->bdev)) - filp->f_mode |= FMODE_NOWAIT; + bdev = blkdev_get_no_open(inode->i_rdev); + if (!bdev) + return -ENXIO; - filp->f_mapping = handle->bdev->bd_inode->i_mapping; - filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping); - filp->private_data = handle; - return 0; + ret = bdev_open(bdev, mode, holder, NULL, filp); + if (ret) + blkdev_put_no_open(bdev); + return ret; } static int blkdev_release(struct inode *inode, struct file *filp) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 495f55587207..2f5dbde23094 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1475,13 +1475,6 @@ extern const struct blk_holder_ops fs_holder_ops; (BLK_OPEN_READ | BLK_OPEN_RESTRICT_WRITES | \ (((flags) & SB_RDONLY) ? 0 : BLK_OPEN_WRITE)) -/* @bdev_handle will be removed soon. */ -struct bdev_handle { - struct block_device *bdev; - void *holder; - blk_mode_t mode; -}; - struct file *bdev_file_open_by_dev(dev_t dev, blk_mode_t mode, void *holder, const struct blk_holder_ops *hops); struct file *bdev_file_open_by_path(const char *path, blk_mode_t mode, diff --git a/include/linux/fs.h b/include/linux/fs.h index e9291e27cc47..6e0714d35d9b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1327,12 +1327,6 @@ struct super_block { struct list_head s_inodes_wb; /* writeback inodes */ } __randomize_layout; -/* Temporary helper that will go away. */ -static inline struct bdev_handle *sb_bdev_handle(struct super_block *sb) -{ - return sb->s_bdev_file->private_data; -} - static inline struct user_namespace *i_user_ns(const struct inode *inode) { return inode->i_sb->s_user_ns;