From mboxrd@z Thu Jan 1 00:00:00 1970 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 EFA555FEE6; Thu, 21 Aug 2025 01:12:34 +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=1755738755; cv=none; b=N86wMQSuzsORpTFGTsqPgoaDEFiWrt3+Jqct4iPTruv3YaRsSQiAgxaBwvMxlzi8kifpiofyOgDMjTwN1OVAjpWFw95xpxuiOkBz5merBWwcoU1t/iL6um8Z+NByN4qhjKqH7bjJ5m0qjnnH9t11wTSv3E9ogJAu+etUgCJ837I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755738755; c=relaxed/simple; bh=LOj7HHCfQdDb843+OqvACigpr1JaCwZpO9fMJJWEaxE=; h=Date:Subject:From:To:Cc:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=iaZ9ABvlg+5KBWPwA6hhiYHbh5B+rahXCnXVWSI3s054ovvEnOT6HRcq61m4u+GtV34HbUtao/sPABpvfCXVfXpAnlbp3yo9IFTjADoP0/wI92HN6JIQ8wQ9YbD1p4EJoZdarv6OooxKzvHUEJB2kpnD6S+CLx4vfBFldN1bduE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oh7qVrJr; 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="oh7qVrJr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7C46AC4CEE7; Thu, 21 Aug 2025 01:12:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755738754; bh=LOj7HHCfQdDb843+OqvACigpr1JaCwZpO9fMJJWEaxE=; h=Date:Subject:From:To:Cc:In-Reply-To:References:From; b=oh7qVrJrkFqzvVvl6UfB0KsCymr4g5mVcuTM0IRELk5/UHCcI7Rn4iJC0HS+iH7t8 wt8G6xjL3PZgyYrVxv6gnWZUpfWZVkBcz8GP4gLTDCf/ezamLBwm3s8t6IemafT2z+ 6RiuMjI7xnxjISdYjcyiggLffAhifCdsBUHaSaZAfWc9NxUEZxflVv9j769ZA+gKa/ 1JPypp0L47ha/GLij0I5tmMDTSJN5l5tv6Zv/kLAONGNrpdADY8GXjxyTMQuoIF/FH 5YmVPUWnHb6cmXW/sbBMIAROpj40Hi7+5JOOPn+V1YiIzNYutcJqWqi8URpD1gzZYN WTGzU9fWhvuVA== Date: Wed, 20 Aug 2025 18:12:34 -0700 Subject: [PATCH 18/20] fuse4fs: use the orphaned inode list From: "Darrick J. Wong" To: tytso@mit.edu Cc: John@groves.net, bernd@bsbernd.com, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, miklos@szeredi.hu, amir73il@gmail.com, joannelkoong@gmail.com, neal@gompa.dev Message-ID: <175573713131.20753.249562496853950632.stgit@frogsfrogsfrogs> In-Reply-To: <175573712721.20753.5223489399594191991.stgit@frogsfrogsfrogs> References: <175573712721.20753.5223489399594191991.stgit@frogsfrogsfrogs> Precedence: bulk X-Mailing-List: linux-ext4@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit From: Darrick J. Wong Put open but unlinked files on the orphan list, and remove them when the last open fd releases the inode. Signed-off-by: "Darrick J. Wong" --- misc/fuse4fs.c | 181 +++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 178 insertions(+), 3 deletions(-) diff --git a/misc/fuse4fs.c b/misc/fuse4fs.c index e2a9e7bfe54b00..1d1797a483a139 100644 --- a/misc/fuse4fs.c +++ b/misc/fuse4fs.c @@ -955,6 +955,13 @@ static int fuse4fs_inum_access(struct fuse4fs *ff, const struct fuse_ctx *ctxt, inode_uid(inode), inode_gid(inode), ctxt->uid, ctxt->gid); + /* linked files cannot be on the unlinked list or deleted */ + if (inode.i_dtime != 0) { + dbg_printf(ff, "%s: unlinked ino=%d dtime=0x%x\n", + __func__, ino, inode.i_dtime); + return -ENOENT; + } + /* existence check */ if (mask == 0) return 0; @@ -2140,9 +2147,80 @@ static int fuse4fs_remove_ea_inodes(struct fuse4fs *ff, ext2_ino_t ino, return 0; } +static int fuse4fs_add_to_orphans(struct fuse4fs *ff, ext2_ino_t ino, + struct ext2_inode_large *inode) +{ + ext2_filsys fs = ff->fs; + + dbg_printf(ff, "%s: orphan ino=%d dtime=%d next=%d\n", + __func__, ino, inode->i_dtime, fs->super->s_last_orphan); + + inode->i_dtime = fs->super->s_last_orphan; + fs->super->s_last_orphan = ino; + ext2fs_mark_super_dirty(fs); + + return 0; +} + +static int fuse4fs_remove_from_orphans(struct fuse4fs *ff, ext2_ino_t ino, + struct ext2_inode_large *inode) +{ + ext2_filsys fs = ff->fs; + ext2_ino_t prev_orphan; + errcode_t err; + + dbg_printf(ff, "%s: super=%d ino=%d next=%d\n", + __func__, fs->super->s_last_orphan, ino, inode->i_dtime); + + /* If we're lucky, the ondisk superblock points to us */ + if (fs->super->s_last_orphan == ino) { + dbg_printf(ff, "%s: superblock\n", __func__); + + fs->super->s_last_orphan = inode->i_dtime; + inode->i_dtime = 0; + ext2fs_mark_super_dirty(fs); + return 0; + } + + /* Otherwise walk the ondisk orphan list. */ + prev_orphan = fs->super->s_last_orphan; + while (prev_orphan != 0) { + struct ext2_inode_large orphan; + + err = fuse4fs_read_inode(fs, prev_orphan, &orphan); + if (err) + return translate_error(fs, prev_orphan, err); + + if (orphan.i_dtime == prev_orphan) + return translate_error(fs, prev_orphan, + EXT2_ET_FILESYSTEM_CORRUPTED); + + if (orphan.i_dtime == ino) { + dbg_printf(ff, "%s: prev=%d\n", + __func__, prev_orphan); + + orphan.i_dtime = inode->i_dtime; + inode->i_dtime = 0; + + err = fuse4fs_write_inode(fs, prev_orphan, &orphan); + if (err) + return translate_error(fs, prev_orphan, err); + + return 0; + } + + dbg_printf(ff, "%s: orphan=%d next=%d\n", + __func__, prev_orphan, orphan.i_dtime); + prev_orphan = orphan.i_dtime; + } + + return translate_error(fs, ino, EXT2_ET_FILESYSTEM_CORRUPTED); +} + static int fuse4fs_remove_inode(struct fuse4fs *ff, ext2_ino_t ino) { ext2_filsys fs = ff->fs; + struct fuse4fs_inode *fi; errcode_t err; struct ext2_inode_large inode; int ret = 0; @@ -2159,7 +2237,6 @@ static int fuse4fs_remove_inode(struct fuse4fs *ff, ext2_ino_t ino) return 0; /* XXX: already done? */ case 1: inode.i_links_count--; - ext2fs_set_dtime(fs, EXT2_INODE(&inode)); break; default: inode.i_links_count--; @@ -2172,6 +2249,26 @@ static int fuse4fs_remove_inode(struct fuse4fs *ff, ext2_ino_t ino) if (inode.i_links_count) goto write_out; + err = fuse4fs_iget(ff, ino, &fi); + if (err) + return translate_error(fs, ino, err); + + dbg_printf(ff, "%s: put ino=%d opencount=%d\n", __func__, ino, + fi->i_open_count); + + /* + * The file is unlinked but still open; add it to the orphan list and + * free it later. + */ + if (fi->i_open_count > 0) { + fuse4fs_iput(ff, fi); + ret = fuse4fs_add_to_orphans(ff, ino, &inode); + if (ret) + return ret; + + goto write_out; + } + fuse4fs_iput(ff, fi); if (ext2fs_has_feature_ea_inode(fs->super)) { ret = fuse4fs_remove_ea_inodes(ff, ino, &inode); @@ -2191,6 +2288,7 @@ static int fuse4fs_remove_inode(struct fuse4fs *ff, ext2_ino_t ino) return translate_error(fs, ino, err); } + ext2fs_set_dtime(fs, EXT2_INODE(&inode)); ext2fs_inode_alloc_stats2(fs, ino, -1, LINUX_S_ISDIR(inode.i_mode)); @@ -2735,6 +2833,16 @@ static void op_link(fuse_req_t req, fuse_ino_t child_fino, if (ret) goto out2; + /* + * Linking a file back into the filesystem requires removing it from + * the orphan list. + */ + if (inode.i_links_count == 0) { + ret = fuse4fs_remove_from_orphans(ff, child, &inode); + if (ret) + goto out2; + } + inode.i_links_count++; ret = update_ctime(fs, child, &inode); if (ret) @@ -3015,7 +3123,8 @@ static void detect_linux_executable_open(int kernel_flags, int *access_check, #endif /* __linux__ */ static int fuse4fs_open_file(struct fuse4fs *ff, const struct fuse_ctx *ctxt, - ext2_ino_t ino, struct fuse_file_info *fp) + ext2_ino_t ino, + struct fuse_file_info *fp) { ext2_filsys fs = ff->fs; errcode_t err; @@ -3089,6 +3198,8 @@ static int fuse4fs_open_file(struct fuse4fs *ff, const struct fuse_ctx *ctxt, file->fi->i_open_count++; fuse4fs_set_handle(fp, file); + dbg_printf(ff, "%s: ino=%d fh=%p opencount=%d\n", __func__, ino, file, + file->fi->i_open_count); out: if (ret) @@ -3105,6 +3216,8 @@ static void op_open(fuse_req_t req, fuse_ino_t fino, struct fuse_file_info *fp) FUSE4FS_CHECK_CONTEXT(req); FUSE4FS_CONVERT_FINO(req, &ino, fino); + dbg_printf(ff, "%s: ino=%d\n", __func__, ino); + fuse4fs_start(ff); ret = fuse4fs_open_file(ff, ctxt, ino, fp); fuse4fs_finish(ff, ret); @@ -3253,6 +3366,55 @@ static void op_write(fuse_req_t req, fuse_ino_t fino EXT2FS_ATTR((unused)), fuse_reply_err(req, -ret); } +static int fuse4fs_free_unlinked(struct fuse4fs *ff, ext2_ino_t ino) +{ + struct ext2_inode_large inode; + ext2_filsys fs = ff->fs; + errcode_t err; + int ret = 0; + + err = fuse4fs_read_inode(fs, ino, &inode); + if (err) + return translate_error(fs, ino, err); + + if (inode.i_links_count > 0) + return 0; + + dbg_printf(ff, "%s: ino=%d links=%d\n", __func__, ino, + inode.i_links_count); + + if (ext2fs_has_feature_ea_inode(fs->super)) { + ret = fuse4fs_remove_ea_inodes(ff, ino, &inode); + if (ret) + return ret; + } + + /* Nobody holds this file; free its blocks! */ + err = ext2fs_free_ext_attr(fs, ino, &inode); + if (err) + return translate_error(fs, ino, err); + + if (ext2fs_inode_has_valid_blocks2(fs, EXT2_INODE(&inode))) { + err = ext2fs_punch(fs, ino, EXT2_INODE(&inode), NULL, + 0, ~0ULL); + if (err) + return translate_error(fs, ino, err); + } + + ret = fuse4fs_remove_from_orphans(ff, ino, &inode); + if (ret) + return ret; + + ext2fs_set_dtime(fs, EXT2_INODE(&inode)); + ext2fs_inode_alloc_stats2(fs, ino, -1, LINUX_S_ISDIR(inode.i_mode)); + + err = fuse4fs_write_inode(fs, ino, &inode); + if (err) + return translate_error(fs, ino, err); + + return 0; +} + static void op_release(fuse_req_t req, fuse_ino_t fino EXT2FS_ATTR((unused)), struct fuse_file_info *fp) { @@ -3264,9 +3426,21 @@ static void op_release(fuse_req_t req, fuse_ino_t fino EXT2FS_ATTR((unused)), FUSE4FS_CHECK_CONTEXT(req); FUSE4FS_CHECK_HANDLE(req, fh); - dbg_printf(ff, "%s: ino=%d\n", __func__, fh->ino); + dbg_printf(ff, "%s: ino=%d fh=%p opencount=%u\n", + __func__, fh->ino, fh, fh->fi->i_open_count); + fs = fuse4fs_start(ff); + /* + * If the file is no longer open and is unlinked, free it, which + * removes it from the ondisk list. + */ + if (--fh->fi->i_open_count == 0) { + ret = fuse4fs_free_unlinked(ff, fh->ino); + if (ret) + goto out_iput; + } + if ((fp->flags & O_SYNC) && fuse4fs_is_writeable(ff) && (fh->open_flags & EXT2_FILE_WRITE)) { @@ -3275,6 +3449,7 @@ static void op_release(fuse_req_t req, fuse_ino_t fino EXT2FS_ATTR((unused)), ret = translate_error(fs, fh->ino, err); } +out_iput: fuse4fs_iput(ff, fh->fi); fp->fh = 0; fuse4fs_finish(ff, ret);