From patchwork Tue Jan 7 18:34:51 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Howells X-Patchwork-Id: 13929504 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 BA8DF1F4E33 for ; Tue, 7 Jan 2025 18:35:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736274919; cv=none; b=e5HNe/cwkr9xWTmYtERV4UYL67FtJd8svXQ2hsDeH+XHH9jfQGUMUc1TEwLVC+u4ogiMsV5m6Fgx+Yt/CYoDgvtvbyYo84YfEdGUjXAunybt56NZMKF29UPMTA2is7msBTYOG2tsaaESejrFfOHbsdyGEIDSmTx8zVU9vLtLTNk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736274919; c=relaxed/simple; bh=vRacdDmEkDpCsbaiCLNUCJzPUuy8W4zt0Na19HlwvNQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UaYQ4CsdrH9iGCmZWQKy6dACjASin20Ecb2P1zV3HTA/nv3DqI8BR0iY/uudZDUUAMZhSksXG4OloFxNlk4xw5FMRnNNlMO1HT+uT3HWqH/07zBPbL+hU3sFNbUECc+h1sSnM44JluvkQ9Rj1XI15USZTareujdq0t52NypKQ2E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=avgGW1Ts; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="avgGW1Ts" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1736274914; h=from:from:reply-to:subject:subject: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=3U8s9dlnuRhzN+hAAFt0ClTwk9PTXQs8oU+1HK2h3NU=; b=avgGW1TsmrRBXh9VR5XvtX7WoXYK9hXuNEL+uqlssx6mmD+C2MrkmEiEIO4c1DZR2h3lMZ Dy7GbFSE+iD0PMA1kkescBU4fsCgidTHQQ6ll91Oks1ukiZGtaRt8fB7+ayCqVRRpaU228 MKT7xXvkb7NFMYDgdkbeWSkwX4tLsN8= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-605-4dXgXPleO5GVfISdWt_SOw-1; Tue, 07 Jan 2025 13:35:09 -0500 X-MC-Unique: 4dXgXPleO5GVfISdWt_SOw-1 X-Mimecast-MFC-AGG-ID: 4dXgXPleO5GVfISdWt_SOw Received: from mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.40]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7711E1955F56; Tue, 7 Jan 2025 18:35:08 +0000 (UTC) Received: from warthog.procyon.org.com (unknown [10.42.28.12]) by mx-prod-int-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 74615195606B; Tue, 7 Jan 2025 18:35:06 +0000 (UTC) From: David Howells To: Marc Dionne Cc: David Howells , Christian Brauner , linux-afs@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 3/3] afs: Make /afs/@cell and /afs/.@cell symlinks Date: Tue, 7 Jan 2025 18:34:51 +0000 Message-ID: <20250107183454.608451-4-dhowells@redhat.com> In-Reply-To: <20250107183454.608451-1-dhowells@redhat.com> References: <20250107183454.608451-1-dhowells@redhat.com> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.0 on 10.30.177.40 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 cc: Marc Dionne cc: linux-afs@lists.infradead.org --- Notes: Changes ======= ver #2) - Directly create the symlink nodes rather than going through lookup. 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 f80a4244b9d2..d8bf52f77d93 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 a0aed1a428a1..de0e2301a037 100644 --- a/include/trace/events/afs.h +++ b/include/trace/events/afs.h @@ -168,12 +168,14 @@ 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 ") \ 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") \