From patchwork Thu Jun 8 03:24:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Chamberlain X-Patchwork-Id: 13271568 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D7005C83003 for ; Thu, 8 Jun 2023 03:24:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233550AbjFHDYW (ORCPT ); Wed, 7 Jun 2023 23:24:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233829AbjFHDYR (ORCPT ); Wed, 7 Jun 2023 23:24:17 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE7D32137; Wed, 7 Jun 2023 20:24:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description; bh=i8udE4lZ9zFqOy/CU8rsbiperqptCexBzEc3SlSva0A=; b=FqszdcQsYtn+7QaEoWq67nnDPF 5Eg7Zs3vYghbDl9L/ZdzusDwSf7l2rNkyQmNh7Z53nlKNwoVBTRJsa6kodwBwycgq4dXbWyFASKdm M82I9wh0LfRFzH792mSlPkUC187ToVFJVlM+Jw65mgJuRDVAI6fFFTuS28HZo33fhGVOgWDGHgpWW Ybf/GOJ8BSBsBXY6FvO3Ue13e4nOlMiKX7/7KznLwPcYEhIOr/HGyqRYaqonj1CK0AGSA+qL80nWK 0Vu1+8vslH34F+tJJEFbeoACTr6y36JHZ9ldkj1KopEuA57cYV7tCJR79s+FTt6+oiY2zYm6MFT/6 hrzrNh9Q==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1q76Fr-007uuo-37; Thu, 08 Jun 2023 03:24:07 +0000 From: Luis Chamberlain To: hch@infradead.org, djwong@kernel.org, dchinner@redhat.com, kbusch@kernel.org, willy@infradead.org Cc: hare@suse.de, ritesh.list@gmail.com, rgoldwyn@suse.com, jack@suse.cz, patches@lists.linux.dev, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, p.raghav@samsung.com, da.gomez@samsung.com, rohan.puri@samsung.com, rpuri.linux@gmail.com, mcgrof@kernel.org, corbet@lwn.net, jake@lwn.net Subject: [RFC 4/4] bdev: extend bdev inode with it's own super_block Date: Wed, 7 Jun 2023 20:24:04 -0700 Message-Id: <20230608032404.1887046-5-mcgrof@kernel.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20230608032404.1887046-1-mcgrof@kernel.org> References: <20230608032404.1887046-1-mcgrof@kernel.org> MIME-Version: 1.0 Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org We currently share a single super_block for the block device cache, each block device corresponds to one inode on that super_block. This implicates sharing one aops operation though, and in the near future we want to be able to instead support using iomap on the super_block for different block devices. To allow more flexibility use a super_block per block device, so that we can eventually allow co-existence with pure-iomap requirements and block devices which require buffer-heads. Signed-off-by: Luis Chamberlain --- block/bdev.c | 94 +++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 78 insertions(+), 16 deletions(-) diff --git a/block/bdev.c b/block/bdev.c index 2b16afc2bd2a..3ab952a77a11 100644 --- a/block/bdev.c +++ b/block/bdev.c @@ -30,9 +30,14 @@ #include "../fs/internal.h" #include "blk.h" +static LIST_HEAD(bdev_inode_list); +static DEFINE_MUTEX(bdev_inode_mutex); + struct bdev_inode { struct block_device bdev; struct inode vfs_inode; + struct vfsmount *bd_mnt; + struct list_head list; }; static inline struct bdev_inode *BDEV_I(struct inode *inode) @@ -321,10 +326,28 @@ static struct inode *bdev_alloc_inode(struct super_block *sb) return &ei->vfs_inode; } +static void bdev_remove_inode(struct bdev_inode *binode) +{ + struct bdev_inode *bdev_inode, *tmp; + + kern_unmount(binode->bd_mnt); + + mutex_lock(&bdev_inode_mutex); + list_for_each_entry_safe(bdev_inode, tmp, &bdev_inode_list, list) { + if (bdev_inode == binode) { + list_del_init(&bdev_inode->list); + break; + } + } + mutex_unlock(&bdev_inode_mutex); +} + static void bdev_free_inode(struct inode *inode) { struct block_device *bdev = I_BDEV(inode); + bdev_remove_inode(BDEV_I(inode)); + free_percpu(bdev->bd_stats); kfree(bdev->bd_meta_info); @@ -378,12 +401,9 @@ static struct file_system_type bd_type = { .kill_sb = kill_anon_super, }; -struct super_block *blockdev_superblock __read_mostly; - void __init bdev_cache_init(void) { int err; - static struct vfsmount *bd_mnt; bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| @@ -392,20 +412,23 @@ void __init bdev_cache_init(void) err = register_filesystem(&bd_type); if (err) panic("Cannot register bdev pseudo-fs"); - bd_mnt = kern_mount(&bd_type); - if (IS_ERR(bd_mnt)) - panic("Cannot create bdev pseudo-fs"); - blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ } struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) { + struct vfsmount *bd_mnt; struct block_device *bdev; struct inode *inode; - inode = new_inode(blockdev_superblock); - if (!inode) + bd_mnt = vfs_kern_mount(&bd_type, SB_KERNMOUNT, bd_type.name, NULL); + if (IS_ERR(bd_mnt)) return NULL; + + inode = new_inode(bd_mnt->mnt_sb); + if (!inode) { + kern_unmount(bd_mnt); + goto err_out; + } inode->i_mode = S_IFBLK; inode->i_rdev = 0; #ifdef CONFIG_BUFFER_HEAD @@ -426,12 +449,14 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) else bdev->bd_has_submit_bio = false; bdev->bd_stats = alloc_percpu(struct disk_stats); - if (!bdev->bd_stats) { - iput(inode); - return NULL; - } + if (!bdev->bd_stats) + goto err_out; bdev->bd_disk = disk; + BDEV_I(inode)->bd_mnt = bd_mnt; /* For writeback */ return bdev; +err_out: + iput(inode); + return NULL; } void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors) @@ -444,13 +469,16 @@ void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors) void bdev_add(struct block_device *bdev, dev_t dev) { + struct inode *inode = bdev->bd_inode; + bdev->bd_dev = dev; bdev->bd_inode->i_rdev = dev; bdev->bd_inode->i_ino = dev; insert_inode_hash(bdev->bd_inode); + list_add_tail(&BDEV_I(inode)->list, &bdev_inode_list); } -long nr_blockdev_pages(void) +static long nr_blockdev_pages_sb(struct super_block *blockdev_superblock) { struct inode *inode; long ret = 0; @@ -463,6 +491,19 @@ long nr_blockdev_pages(void) return ret; } +long nr_blockdev_pages(void) +{ + struct bdev_inode *bdev_inode; + long ret = 0; + + mutex_lock(&bdev_inode_mutex); + list_for_each_entry(bdev_inode, &bdev_inode_list, list) + ret += nr_blockdev_pages_sb(bdev_inode->bd_mnt->mnt_sb); + mutex_unlock(&bdev_inode_mutex); + + return ret; +} + /** * bd_may_claim - test whether a block device can be claimed * @bdev: block device of interest @@ -672,7 +713,18 @@ static void blkdev_put_part(struct block_device *part, fmode_t mode) static struct inode *blkdev_inode_lookup(dev_t dev) { - return ilookup(blockdev_superblock, dev); + struct bdev_inode *bdev_inode; + struct inode *inode = NULL; + + mutex_lock(&bdev_inode_mutex); + list_for_each_entry(bdev_inode, &bdev_inode_list, list) { + inode = ilookup(bdev_inode->bd_mnt->mnt_sb, dev); + if (inode) + break; + } + mutex_unlock(&bdev_inode_mutex); + + return inode; } struct block_device *blkdev_get_no_open(dev_t dev) @@ -961,7 +1013,7 @@ int __invalidate_device(struct block_device *bdev, bool kill_dirty) } EXPORT_SYMBOL(__invalidate_device); -void sync_bdevs(bool wait) +static void sync_bdev_sb(struct super_block *blockdev_superblock, bool wait) { struct inode *inode, *old_inode = NULL; @@ -1013,6 +1065,16 @@ void sync_bdevs(bool wait) iput(old_inode); } +void sync_bdevs(bool wait) +{ + struct bdev_inode *bdev_inode; + + mutex_lock(&bdev_inode_mutex); + list_for_each_entry(bdev_inode, &bdev_inode_list, list) + sync_bdev_sb(bdev_inode->bd_mnt->mnt_sb, wait); + mutex_unlock(&bdev_inode_mutex); +} + /* * Handle STATX_DIOALIGN for block devices. *