Return-Path: linux-nfs-owner@vger.kernel.org Received: from aserp1040.oracle.com ([141.146.126.69]:34136 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751133Ab3HOUt1 (ORCPT ); Thu, 15 Aug 2013 16:49:27 -0400 Message-ID: <520D3EA7.1010109@oracle.com> Date: Thu, 15 Aug 2013 15:48:39 -0500 From: Dave Kleikamp MIME-Version: 1.0 To: Christian Kujau CC: "J. Bruce Fields" , Karl Schmidt , Jonathan McDowell , jfs-discussion@lists.sourceforge.net, 714974@bugs.debian.org, Ben Hutchings , linux-nfs@vger.kernel.org Subject: [PATCH] jfs: fix readdir cookie incompatibility with NFSv4 References: <1373245980.3428.46.camel@deadeye.wl.decadent.org.uk> <520554A5.3060401@xtronics.com> <20130812162924.GB2395@fieldses.org> <520C50F7.3010209@oracle.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Sender: linux-nfs-owner@vger.kernel.org List-ID: This patch replaces the one I posted yesterday. I like this better since it doesn't require fixing existing on-disk cookies or skipping a position in the in-inode index table. NFSv4 reserves readdir cookie values 0-2 for special entries (. and ..), but jfs allows a value of 2 for a non-special entry. This incompatibility can result in the nfs client reporting a readdir loop. This patch doesn't change the value stored internally, but adds one to the value exposed to the iterate method. Signed-off-by: Dave Kleikamp --- fs/jfs/jfs_dtree.c | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-) diff --git a/fs/jfs/jfs_dtree.c b/fs/jfs/jfs_dtree.c index 8743ba9..0ec767e 100644 --- a/fs/jfs/jfs_dtree.c +++ b/fs/jfs/jfs_dtree.c @@ -3047,6 +3047,14 @@ int jfs_readdir(struct file *file, struct dir_context *ctx) dir_index = (u32) ctx->pos; + /* + * NFSv4 reserves cookies 1 and 2 for . and .. so we add + * the value we return to the vfs is one greater than the + * one we use internally. + */ + if (dir_index) + dir_index--; + if (dir_index > 1) { struct dir_table_slot dirtab_slot; @@ -3086,7 +3094,7 @@ int jfs_readdir(struct file *file, struct dir_context *ctx) if (p->header.flag & BT_INTERNAL) { jfs_err("jfs_readdir: bad index table"); DT_PUTPAGE(mp); - ctx->pos = -1; + ctx->pos = DIREND; return 0; } } else { @@ -3094,14 +3102,14 @@ int jfs_readdir(struct file *file, struct dir_context *ctx) /* * self "." */ - ctx->pos = 0; + ctx->pos = 1; if (!dir_emit(ctx, ".", 1, ip->i_ino, DT_DIR)) return 0; } /* * parent ".." */ - ctx->pos = 1; + ctx->pos = 2; if (!dir_emit(ctx, "..", 2, PARENT(ip), DT_DIR)) return 0; @@ -3122,22 +3130,23 @@ int jfs_readdir(struct file *file, struct dir_context *ctx) /* * Legacy filesystem - OS/2 & Linux JFS < 0.3.6 * - * pn = index = 0: First entry "." - * pn = 0; index = 1: Second entry ".." + * pn = 0; index = 1: First entry "." + * pn = 0; index = 2: Second entry ".." * pn > 0: Real entries, pn=1 -> leftmost page * pn = index = -1: No more entries */ dtpos = ctx->pos; - if (dtpos == 0) { + if (dtpos < 2) { /* build "." entry */ + ctx->pos = 1; if (!dir_emit(ctx, ".", 1, ip->i_ino, DT_DIR)) return 0; - dtoffset->index = 1; + dtoffset->index = 2; ctx->pos = dtpos; } if (dtoffset->pn == 0) { - if (dtoffset->index == 1) { + if (dtoffset->index == 2) { /* build ".." entry */ if (!dir_emit(ctx, "..", 2, PARENT(ip), DT_DIR)) return 0; @@ -3228,6 +3237,12 @@ int jfs_readdir(struct file *file, struct dir_context *ctx) } jfs_dirent->position = unique_pos++; } + /* + * We add 1 to the index because we may + * use a value of 2 internally, and NFSv4 + * doesn't like that. + */ + jfs_dirent->position++; } else { jfs_dirent->position = dtpos; len = min(d_namleft, DTLHDRDATALEN_LEGACY); -- 1.8.3.4