From patchwork Fri Dec 20 02:54:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 13916097 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A5D831632C8; Fri, 20 Dec 2024 03:09:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734664154; cv=none; b=JPNEjJIlVx6g+4tH4BBLLUtA1pdJkPU4vZH4hmjCm9NI/gUyQi/UMGNUV1AbjWD6x+imx1tnOzlDJqd7shSGi5mAJWkAha6j1SfjyMhmi4wkgyuJJ19H85yATSXshPwt2oNDgLIHyXFo0YJkAkkeTFD8SRG4s7ows1++MISy9JY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734664154; c=relaxed/simple; bh=igjLZU34N84JAJHbkG3DJsr5Py53lspSM/nGwQzLgm8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uZtnEZtQ17bH9wwL8xrp9GFtaZzeCh2Q4W0cpD7yJrlINTkXx+3Oqs/kKkV83GD3tfvUUnTQQdECFpeQN/O2EXAfDO3LXsApWrTaNa7F7pdJZaZmLx5bzlX32pdVyYET1xdKTCobERA5vz2U01XoM743CIB8UQc7yJvKngLbAek= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=LXDUHvSK; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=FUUGJQu8; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=RjTNp9b2; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=DOH2YnTk; arc=none smtp.client-ip=195.135.223.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="LXDUHvSK"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="FUUGJQu8"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="RjTNp9b2"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="DOH2YnTk" Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id E42AD1F385; Fri, 20 Dec 2024 03:09:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1734664151; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=g78TC/Zbx8kwsLCDh78LnjHG14nWVEMWb4e/lUvSCGI=; b=LXDUHvSKAxVzHleis25dnUqV8IpKRuDk5GO/8ijcmuYt5KDBG+gh6KyQsHq3YD1YJyGy7e gprXAs2Sg5z+dftCPBFuzb4UVVaZZvnd7tVhd9yv6H3oJ3fdj9rb0pZuqYYLfiAOsmtITj 1wWfPt0ieIToiZy/3UTDCdpBYz0990M= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1734664151; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=g78TC/Zbx8kwsLCDh78LnjHG14nWVEMWb4e/lUvSCGI=; b=FUUGJQu85zdXk/lvyhN6CF/EDkh8S1i6ui0yCk0VRbW1OWXlWEUuNp5d/G2QVeLzyFQDRN zk82QMPDlK3raLDA== Authentication-Results: smtp-out2.suse.de; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=RjTNp9b2; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=DOH2YnTk DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1734664150; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=g78TC/Zbx8kwsLCDh78LnjHG14nWVEMWb4e/lUvSCGI=; b=RjTNp9b27DSfXom89DQt6DbUZnL1ES/qS28LHCKFsmL2np1bC5cq7qY418T860GG8R6q8H sOdEpsf9LZFwFYQGtdaw7OgoRC7COVLCLA/9ZzKazKjpOfPXKYguQY+x8OnZPDj1X4IoF9 1+vrGk8Of06PIP3DO9aZMTvi5mTvel4= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1734664150; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=g78TC/Zbx8kwsLCDh78LnjHG14nWVEMWb4e/lUvSCGI=; b=DOH2YnTkN5bh0qVRjo/XzqC582Il62loqkNL3QhPPDJSm+60ceCoUXMNI3iu9WJCTYLtu7 MMXJZnVk43laxPBg== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id CC20913A32; Fri, 20 Dec 2024 03:09:08 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 42lDINTfZGdTGAAAD6G6ig (envelope-from ); Fri, 20 Dec 2024 03:09:08 +0000 From: NeilBrown To: Alexander Viro , Christian Brauner , Jan Kara , Linus Torvalds Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 05/11] VFS: change kern_path_locked() and user_path_locked_at() to never return negative dentry Date: Fri, 20 Dec 2024 13:54:23 +1100 Message-ID: <20241220030830.272429-6-neilb@suse.de> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241220030830.272429-1-neilb@suse.de> References: <20241220030830.272429-1-neilb@suse.de> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Rspamd-Queue-Id: E42AD1F385 X-Spam-Score: -3.01 X-Rspamd-Action: no action X-Spamd-Result: default: False [-3.01 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; RBL_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:104:10:150:64:97:from]; MIME_TRACE(0.00)[0:+]; TO_DN_SOME(0.00)[]; ARC_NA(0.00)[]; SPAMHAUS_XBL(0.00)[2a07:de40:b281:104:10:150:64:97:from]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; RECEIVED_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:106:10:150:64:167:received]; FROM_EQ_ENVFROM(0.00)[]; R_RATELIMIT(0.00)[from(RLewrxuus8mos16izbn)]; RCVD_TLS_ALL(0.00)[]; DKIM_TRACE(0.00)[suse.de:+]; RCPT_COUNT_FIVE(0.00)[6]; DBL_BLOCKED_OPENRESOLVER(0.00)[imap1.dmz-prg2.suse.org:rdns,imap1.dmz-prg2.suse.org:helo,suse.de:dkim,suse.de:mid,suse.de:email] X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Spam-Flag: NO X-Spam-Level: No callers of kern_path_locked() or user_path_locked_at() want a negative dentry. So change them to return -ENOENT instead. This simplifies callers. This results in a subtle change to bcachefs in that an ioctl will now return -ENOENT in preference to -EXDEV. I believe this restores the behaviour to what it was prior to Commit bbe6a7c899e7 ("bch2_ioctl_subvolume_destroy(): fix locking") Signed-off-by: NeilBrown --- drivers/base/devtmpfs.c | 65 +++++++++++++++++++---------------------- fs/bcachefs/fs-ioctl.c | 4 --- fs/namei.c | 4 +++ kernel/audit_watch.c | 12 ++++---- 4 files changed, 40 insertions(+), 45 deletions(-) diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index b848764ef018..c9e34842139f 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -245,15 +245,12 @@ static int dev_rmdir(const char *name) dentry = kern_path_locked(name, &parent); if (IS_ERR(dentry)) return PTR_ERR(dentry); - if (d_really_is_positive(dentry)) { - if (d_inode(dentry)->i_private == &thread) - err = vfs_rmdir(&nop_mnt_idmap, d_inode(parent.dentry), - dentry); - else - err = -EPERM; - } else { - err = -ENOENT; - } + if (d_inode(dentry)->i_private == &thread) + err = vfs_rmdir(&nop_mnt_idmap, d_inode(parent.dentry), + dentry); + else + err = -EPERM; + dput(dentry); inode_unlock(d_inode(parent.dentry)); path_put(&parent); @@ -310,6 +307,8 @@ static int handle_remove(const char *nodename, struct device *dev) { struct path parent; struct dentry *dentry; + struct kstat stat; + struct path p; int deleted = 0; int err; @@ -317,32 +316,28 @@ static int handle_remove(const char *nodename, struct device *dev) if (IS_ERR(dentry)) return PTR_ERR(dentry); - if (d_really_is_positive(dentry)) { - struct kstat stat; - struct path p = {.mnt = parent.mnt, .dentry = dentry}; - err = vfs_getattr(&p, &stat, STATX_TYPE | STATX_MODE, - AT_STATX_SYNC_AS_STAT); - if (!err && dev_mynode(dev, d_inode(dentry), &stat)) { - struct iattr newattrs; - /* - * before unlinking this node, reset permissions - * of possible references like hardlinks - */ - newattrs.ia_uid = GLOBAL_ROOT_UID; - newattrs.ia_gid = GLOBAL_ROOT_GID; - newattrs.ia_mode = stat.mode & ~0777; - newattrs.ia_valid = - ATTR_UID|ATTR_GID|ATTR_MODE; - inode_lock(d_inode(dentry)); - notify_change(&nop_mnt_idmap, dentry, &newattrs, NULL); - inode_unlock(d_inode(dentry)); - err = vfs_unlink(&nop_mnt_idmap, d_inode(parent.dentry), - dentry, NULL); - if (!err || err == -ENOENT) - deleted = 1; - } - } else { - err = -ENOENT; + p.mnt = parent.mnt; + p.dentry = dentry; + err = vfs_getattr(&p, &stat, STATX_TYPE | STATX_MODE, + AT_STATX_SYNC_AS_STAT); + if (!err && dev_mynode(dev, d_inode(dentry), &stat)) { + struct iattr newattrs; + /* + * before unlinking this node, reset permissions + * of possible references like hardlinks + */ + newattrs.ia_uid = GLOBAL_ROOT_UID; + newattrs.ia_gid = GLOBAL_ROOT_GID; + newattrs.ia_mode = stat.mode & ~0777; + newattrs.ia_valid = + ATTR_UID|ATTR_GID|ATTR_MODE; + inode_lock(d_inode(dentry)); + notify_change(&nop_mnt_idmap, dentry, &newattrs, NULL); + inode_unlock(d_inode(dentry)); + err = vfs_unlink(&nop_mnt_idmap, d_inode(parent.dentry), + dentry, NULL); + if (!err || err == -ENOENT) + deleted = 1; } dput(dentry); inode_unlock(d_inode(parent.dentry)); diff --git a/fs/bcachefs/fs-ioctl.c b/fs/bcachefs/fs-ioctl.c index 405cf08bda34..c5464219b23f 100644 --- a/fs/bcachefs/fs-ioctl.c +++ b/fs/bcachefs/fs-ioctl.c @@ -516,10 +516,6 @@ static long bch2_ioctl_subvolume_destroy(struct bch_fs *c, struct file *filp, ret = -EXDEV; goto err; } - if (!d_is_positive(victim)) { - ret = -ENOENT; - goto err; - } ret = __bch2_unlink(dir, victim, true); if (!ret) { fsnotify_rmdir(dir, victim); diff --git a/fs/namei.c b/fs/namei.c index 395bfbc8fc92..8780406cb4d7 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2743,6 +2743,10 @@ static struct dentry *__kern_path_locked(int dfd, struct filename *name, struct } inode_lock_nested(path->dentry->d_inode, I_MUTEX_PARENT); d = lookup_one_qstr_excl(&last, path->dentry, 0); + if (!IS_ERR(d) && d_is_negative(d)) { + dput(d); + d = ERR_PTR(-ENOENT); + } if (IS_ERR(d)) { inode_unlock(path->dentry->d_inode); path_put(path); diff --git a/kernel/audit_watch.c b/kernel/audit_watch.c index 7f358740e958..e3130675ee6b 100644 --- a/kernel/audit_watch.c +++ b/kernel/audit_watch.c @@ -350,11 +350,10 @@ static int audit_get_nd(struct audit_watch *watch, struct path *parent) struct dentry *d = kern_path_locked(watch->path, parent); if (IS_ERR(d)) return PTR_ERR(d); - if (d_is_positive(d)) { - /* update watch filter fields */ - watch->dev = d->d_sb->s_dev; - watch->ino = d_backing_inode(d)->i_ino; - } + /* update watch filter fields */ + watch->dev = d->d_sb->s_dev; + watch->ino = d_backing_inode(d)->i_ino; + inode_unlock(d_backing_inode(parent->dentry)); dput(d); return 0; @@ -419,7 +418,7 @@ int audit_add_watch(struct audit_krule *krule, struct list_head **list) /* caller expects mutex locked */ mutex_lock(&audit_filter_mutex); - if (ret) { + if (ret && ret != -ENOENT) { audit_put_watch(watch); return ret; } @@ -438,6 +437,7 @@ int audit_add_watch(struct audit_krule *krule, struct list_head **list) h = audit_hash_ino((u32)watch->ino); *list = &audit_inode_hash[h]; + ret = 0; error: path_put(&parent_path); audit_put_watch(watch);