From patchwork Mon Dec 27 12:54:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jingbo Xu X-Patchwork-Id: 12699762 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 DB358C433EF for ; Mon, 27 Dec 2021 12:55:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236787AbhL0MzA (ORCPT ); Mon, 27 Dec 2021 07:55:00 -0500 Received: from out4436.biz.mail.alibaba.com ([47.88.44.36]:5085 "EHLO out4436.biz.mail.alibaba.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236808AbhL0Myz (ORCPT ); Mon, 27 Dec 2021 07:54:55 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R901e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e01424;MF=jefflexu@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0V.wXYUC_1640609692; Received: from localhost(mailfrom:jefflexu@linux.alibaba.com fp:SMTPD_---0V.wXYUC_1640609692) by smtp.aliyun-inc.com(127.0.0.1); Mon, 27 Dec 2021 20:54:53 +0800 From: Jeffle Xu To: dhowells@redhat.com, linux-cachefs@redhat.com, xiang@kernel.org, chao@kernel.org, linux-erofs@lists.ozlabs.org Cc: linux-fsdevel@vger.kernel.org, joseph.qi@linux.alibaba.com, bo.liu@linux.alibaba.com, tao.peng@linux.alibaba.com, gerry@linux.alibaba.com, eguan@linux.alibaba.com, linux-kernel@vger.kernel.org Subject: [PATCH v1 07/23] erofs: add nodev mode Date: Mon, 27 Dec 2021 20:54:28 +0800 Message-Id: <20211227125444.21187-8-jefflexu@linux.alibaba.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20211227125444.21187-1-jefflexu@linux.alibaba.com> References: <20211227125444.21187-1-jefflexu@linux.alibaba.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Until then erofs is exactly blockdev based filesystem. In other using scenarios (e.g. container image), erofs needs to run upon files. This patch introduces a new nodev mode, in which erofs could be mounted from a bootstrap blob file containing the complete erofs image. The following patch will introduce a new mount option "uuid", by which users could specify the bootstrap blob file. Signed-off-by: Jeffle Xu --- fs/erofs/data.c | 13 ++++++++--- fs/erofs/internal.h | 1 + fs/erofs/super.c | 56 +++++++++++++++++++++++++++++++++------------ 3 files changed, 53 insertions(+), 17 deletions(-) diff --git a/fs/erofs/data.c b/fs/erofs/data.c index 477aaff0c832..61fa431d0713 100644 --- a/fs/erofs/data.c +++ b/fs/erofs/data.c @@ -11,11 +11,18 @@ struct page *erofs_get_meta_page(struct super_block *sb, erofs_blk_t blkaddr) { - struct address_space *const mapping = sb->s_bdev->bd_inode->i_mapping; + struct address_space *mapping; struct page *page; - page = read_cache_page_gfp(mapping, blkaddr, - mapping_gfp_constraint(mapping, ~__GFP_FS)); + if (sb->s_bdev) { + mapping = sb->s_bdev->bd_inode->i_mapping; + page = read_cache_page_gfp(mapping, blkaddr, + mapping_gfp_constraint(mapping, ~__GFP_FS)); + } else { + /* TODO: data path in nodev mode */ + page = ERR_PTR(-EINVAL); + } + /* should already be PageUptodate */ if (!IS_ERR(page)) lock_page(page); diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 45fb6f5d11b5..c9ee8c247202 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -67,6 +67,7 @@ struct erofs_mount_opts { unsigned int max_sync_decompress_pages; #endif unsigned int mount_opt; + char *uuid; }; struct erofs_dev_context { diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 6a969b1e0ee6..80c00c34eafc 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -304,15 +304,19 @@ static int erofs_init_devices(struct super_block *sb, } dis = ptr + erofs_blkoff(pos); - bdev = blkdev_get_by_path(dif->path, - FMODE_READ | FMODE_EXCL, - sb->s_type); - if (IS_ERR(bdev)) { - err = PTR_ERR(bdev); - goto err_out; + if (sb->s_bdev) { + bdev = blkdev_get_by_path(dif->path, + FMODE_READ | FMODE_EXCL, + sb->s_type); + if (IS_ERR(bdev)) { + err = PTR_ERR(bdev); + goto err_out; + } + dif->bdev = bdev; + dif->dax_dev = fs_dax_get_by_bdev(bdev); + } else { + /* TODO: multi devs in nodev mode */ } - dif->bdev = bdev; - dif->dax_dev = fs_dax_get_by_bdev(bdev); dif->blocks = le32_to_cpu(dis->blocks); dif->mapped_blkaddr = le32_to_cpu(dis->mapped_blkaddr); sbi->total_blocks += dif->blocks; @@ -337,7 +341,11 @@ static int erofs_read_superblock(struct super_block *sb) void *data; int ret; - page = read_mapping_page(sb->s_bdev->bd_inode->i_mapping, 0, NULL); + /* TODO: metadata path in nodev mode */ + if (sb->s_bdev) + page = read_mapping_page(sb->s_bdev->bd_inode->i_mapping, 0, NULL); + else + page = ERR_PTR(-EOPNOTSUPP); if (IS_ERR(page)) { erofs_err(sb, "cannot read erofs superblock"); return PTR_ERR(page); @@ -633,9 +641,12 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) sb->s_magic = EROFS_SUPER_MAGIC; - if (!sb_set_blocksize(sb, EROFS_BLKSIZ)) { + if (sb->s_bdev && !sb_set_blocksize(sb, EROFS_BLKSIZ)) { erofs_err(sb, "failed to set erofs blksize"); return -EINVAL; + } else { + sb->s_blocksize = EROFS_BLKSIZ; + sb->s_blocksize_bits = LOG_BLOCK_SIZE; } sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); @@ -644,16 +655,22 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) sb->s_fs_info = sbi; sbi->opt = ctx->opt; - sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev); sbi->devs = ctx->devs; ctx->devs = NULL; + if (sb->s_bdev) + sbi->dax_dev = fs_dax_get_by_bdev(sb->s_bdev); + else + sbi->dax_dev = NULL; + err = erofs_read_superblock(sb); if (err) return err; if (test_opt(&sbi->opt, DAX_ALWAYS) && - !dax_supported(sbi->dax_dev, sb->s_bdev, EROFS_BLKSIZ, 0, bdev_nr_sectors(sb->s_bdev))) { + (!sbi->dax_dev || + !dax_supported(sbi->dax_dev, sb->s_bdev, EROFS_BLKSIZ, 0, + bdev_nr_sectors(sb->s_bdev)))) { errorfc(fc, "DAX unsupported by block device. Turning off DAX."); clear_opt(&sbi->opt, DAX_ALWAYS); } @@ -701,6 +718,10 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) static int erofs_fc_get_tree(struct fs_context *fc) { + struct erofs_fs_context *ctx = fc->fs_private; + + if (ctx->opt.uuid) + return get_tree_nodev(fc, erofs_fc_fill_super); return get_tree_bdev(fc, erofs_fc_fill_super); } @@ -789,7 +810,10 @@ static void erofs_kill_sb(struct super_block *sb) WARN_ON(sb->s_magic != EROFS_SUPER_MAGIC); - kill_block_super(sb); + if (sb->s_bdev) + kill_block_super(sb); + else + generic_shutdown_super(sb); sbi = EROFS_SB(sb); if (!sbi) @@ -889,7 +913,11 @@ static int erofs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct super_block *sb = dentry->d_sb; struct erofs_sb_info *sbi = EROFS_SB(sb); - u64 id = huge_encode_dev(sb->s_bdev->bd_dev); + u64 id = 0; + + /* TODO: fsid in nodev mode */ + if (sb->s_bdev) + id = huge_encode_dev(sb->s_bdev->bd_dev); buf->f_type = sb->s_magic; buf->f_bsize = EROFS_BLKSIZ;