From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 63DB5284662; Tue, 21 Jul 2026 19:46:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784663206; cv=none; b=PhnMhuhrCzOK7sfIg+/eLbg9/s0hopQK1Tu1Yn04/zLILkEHx7Ek0aukjz9zDNaPX+dnxNshi32EpEWrgwX+X9xkZPoCC3ftUAPrYfEcof2XyQ+fMXvgfAjjIarA3cJVly55JQu6xpOHMZpOC2gkpdA/cgZJnk5Whtd6gvH+4Qs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784663206; c=relaxed/simple; bh=buvTcD/RqIHtbAoTYko8svXvN+pyp4pRBiVwZle2Niw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RB07dsTfd3mfino9ZxOZbU0MCBZdZ9NbbXP8m8Ksnf/brJ7YLar2xWv3JBMYiIx6rXUaxGeD3EA0Vwj8Y1mlZ81FXlJzG4GEczB2tyb0G6IVa4aWnTJ2i/A0ZPB2mLKEI05GTGvpgAxDl0Rtjh7ZeRkhGuxbFcf73zOzKMW7WFs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yEnJlsk0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="yEnJlsk0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF26F1F000E9; Tue, 21 Jul 2026 19:46:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784663205; bh=qiebxwnwGBE9qAhtixcCgOiDhLbtBI+6dUnzkQ0geI0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=yEnJlsk0KCxUko0/fNpwekb4tv9o1Do3zvDf3s6sr4/5/z2WmeIt4Pn1oKZG/fhep Q4iIYTIMwh6UO52j/Q1ZumJ8tr1igsqvYjTU/sfyV9Xvlk3gARECl//EQCskFynSS6 ++tFs8Mpp729IxibsGOIB6TRgELePLyM0AzdA0S4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Howells , Marc Dionne , linux-afs@lists.infradead.org, Christian Brauner , Sasha Levin Subject: [PATCH 6.12 0733/1276] afs: Make /afs/@cell and /afs/.@cell symlinks Date: Tue, 21 Jul 2026 17:19:36 +0200 Message-ID: <20260721152502.485728599@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152446.065700225@linuxfoundation.org> References: <20260721152446.065700225@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Howells [ Upstream commit 30bca65bbbae13f32ee4f2897c55a496ea8132cf ] Make /afs/@cell a symlink in the /afs dynamic root to match what other AFS clients do rather than doing a substitution in the dentry name. This has the bonus of being tab-expandable also. Further, provide a /afs/.@cell symlink to point to the dotted cell share. Signed-off-by: David Howells Link: https://lore.kernel.org/r/20250107183454.608451-4-dhowells@redhat.com cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner Stable-dep-of: c9c3b615a462 ("afs: Fix misplaced inc of net->cells_outstanding") Signed-off-by: Sasha Levin --- fs/afs/dynroot.c | 177 +++++++++++++++++++++++++++---------- include/trace/events/afs.h | 2 + 2 files changed, 131 insertions(+), 48 deletions(-) diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c index f80a4244b9d274..d8bf52f77d9302 100644 --- a/fs/afs/dynroot.c +++ b/fs/afs/dynroot.c @@ -185,50 +185,6 @@ struct inode *afs_try_auto_mntpt(struct dentry *dentry, struct inode *dir) return ret == -ENOENT ? NULL : ERR_PTR(ret); } -/* - * Look up @cell in a dynroot directory. This is a substitution for the - * local cell name for the net namespace. - */ -static struct dentry *afs_lookup_atcell(struct dentry *dentry) -{ - struct afs_cell *cell; - struct afs_net *net = afs_d2net(dentry); - struct dentry *ret; - char *name; - int len; - - if (!net->ws_cell) - return ERR_PTR(-ENOENT); - - ret = ERR_PTR(-ENOMEM); - name = kmalloc(AFS_MAXCELLNAME + 1, GFP_KERNEL); - if (!name) - goto out_p; - - down_read(&net->cells_lock); - cell = net->ws_cell; - if (cell) { - len = cell->name_len; - memcpy(name, cell->name, len + 1); - } - up_read(&net->cells_lock); - - ret = ERR_PTR(-ENOENT); - if (!cell) - goto out_n; - - ret = lookup_one_len(name, dentry->d_parent, len); - - /* We don't want to d_add() the @cell dentry here as we don't want to - * the cached dentry to hide changes to the local cell name. - */ - -out_n: - kfree(name); -out_p: - return ret; -} - /* * Look up an entry in a dynroot directory. */ @@ -247,10 +203,6 @@ static struct dentry *afs_dynroot_lookup(struct inode *dir, struct dentry *dentr return ERR_PTR(-ENAMETOOLONG); } - if (dentry->d_name.len == 5 && - memcmp(dentry->d_name.name, "@cell", 5) == 0) - return afs_lookup_atcell(dentry); - return d_splice_alias(afs_try_auto_mntpt(dentry, dir), dentry); } @@ -343,6 +295,131 @@ void afs_dynroot_rmdir(struct afs_net *net, struct afs_cell *cell) _leave(""); } +static void afs_atcell_delayed_put_cell(void *arg) +{ + struct afs_cell *cell = arg; + + afs_put_cell(cell, afs_cell_trace_put_atcell); +} + +/* + * Read @cell or .@cell symlinks. + */ +static const char *afs_atcell_get_link(struct dentry *dentry, struct inode *inode, + struct delayed_call *done) +{ + struct afs_vnode *vnode = AFS_FS_I(inode); + struct afs_cell *cell; + struct afs_net *net = afs_i2net(inode); + const char *name; + bool dotted = vnode->fid.vnode == 3; + + if (!net->ws_cell) + return ERR_PTR(-ENOENT); + + down_read(&net->cells_lock); + + cell = net->ws_cell; + if (dotted) + name = cell->name - 1; + else + name = cell->name; + afs_get_cell(cell, afs_cell_trace_get_atcell); + set_delayed_call(done, afs_atcell_delayed_put_cell, cell); + + up_read(&net->cells_lock); + return name; +} + +static const struct inode_operations afs_atcell_inode_operations = { + .get_link = afs_atcell_get_link, +}; + +/* + * Look up @cell or .@cell in a dynroot directory. This is a substitution for + * the local cell name for the net namespace. + */ +static struct dentry *afs_dynroot_create_symlink(struct dentry *root, const char *name) +{ + struct afs_vnode *vnode; + struct afs_fid fid = { .vnode = 2, .unique = 1, }; + struct dentry *dentry; + struct inode *inode; + + if (name[0] == '.') + fid.vnode = 3; + + dentry = d_alloc_name(root, name); + if (!dentry) + return ERR_PTR(-ENOMEM); + + inode = iget5_locked(dentry->d_sb, fid.vnode, + afs_iget5_pseudo_test, afs_iget5_pseudo_set, &fid); + if (!inode) { + dput(dentry); + return ERR_PTR(-ENOMEM); + } + + vnode = AFS_FS_I(inode); + + /* there shouldn't be an existing inode */ + if (WARN_ON_ONCE(!(inode->i_state & I_NEW))) { + iput(inode); + dput(dentry); + return ERR_PTR(-EIO); + } + + netfs_inode_init(&vnode->netfs, NULL, false); + simple_inode_init_ts(inode); + set_nlink(inode, 1); + inode->i_size = 0; + inode->i_mode = S_IFLNK | 0555; + inode->i_op = &afs_atcell_inode_operations; + inode->i_uid = GLOBAL_ROOT_UID; + inode->i_gid = GLOBAL_ROOT_GID; + inode->i_blocks = 0; + inode->i_generation = 0; + inode->i_flags |= S_NOATIME; + + unlock_new_inode(inode); + d_splice_alias(inode, dentry); + return dentry; +} + +/* + * Create @cell and .@cell symlinks. + */ +static int afs_dynroot_symlink(struct afs_net *net) +{ + struct super_block *sb = net->dynroot_sb; + struct dentry *root, *symlink, *dsymlink; + int ret; + + /* Let the ->lookup op do the creation */ + root = sb->s_root; + inode_lock(root->d_inode); + symlink = afs_dynroot_create_symlink(root, "@cell"); + if (IS_ERR(symlink)) { + ret = PTR_ERR(symlink); + goto unlock; + } + + dsymlink = afs_dynroot_create_symlink(root, ".@cell"); + if (IS_ERR(dsymlink)) { + ret = PTR_ERR(dsymlink); + dput(symlink); + goto unlock; + } + + /* Note that we're retaining extra refs on the dentries. */ + symlink->d_fsdata = (void *)1UL; + dsymlink->d_fsdata = (void *)1UL; + ret = 0; +unlock: + inode_unlock(root->d_inode); + return ret; +} + /* * Populate a newly created dynamic root with cell names. */ @@ -355,6 +432,10 @@ int afs_dynroot_populate(struct super_block *sb) mutex_lock(&net->proc_cells_lock); net->dynroot_sb = sb; + ret = afs_dynroot_symlink(net); + if (ret < 0) + goto error; + hlist_for_each_entry(cell, &net->proc_cells, proc_link) { ret = afs_dynroot_mkdir(net, cell); if (ret < 0) diff --git a/include/trace/events/afs.h b/include/trace/events/afs.h index 3dddfc6abf0ee3..27bac4d5ac906e 100644 --- a/include/trace/events/afs.h +++ b/include/trace/events/afs.h @@ -170,6 +170,7 @@ enum yfs_cm_operation { #define afs_cell_traces \ EM(afs_cell_trace_alloc, "ALLOC ") \ EM(afs_cell_trace_free, "FREE ") \ + EM(afs_cell_trace_get_atcell, "GET atcell") \ EM(afs_cell_trace_get_queue_dns, "GET q-dns ") \ EM(afs_cell_trace_get_queue_manage, "GET q-mng ") \ EM(afs_cell_trace_get_queue_new, "GET q-new ") \ @@ -177,6 +178,7 @@ enum yfs_cm_operation { EM(afs_cell_trace_get_vol, "GET vol ") \ EM(afs_cell_trace_insert, "INSERT ") \ EM(afs_cell_trace_manage, "MANAGE ") \ + EM(afs_cell_trace_put_atcell, "PUT atcell") \ EM(afs_cell_trace_put_candidate, "PUT candid") \ EM(afs_cell_trace_put_destroy, "PUT destry") \ EM(afs_cell_trace_put_queue_work, "PUT q-work") \ -- 2.53.0