From a103ab32f1683201ab4b61ca53d199be4562a62d Mon Sep 17 00:00:00 2001 From: Dave Kleikamp Date: Thu, 15 Aug 2013 15:36:49 -0500 Subject: jfs: fix readdir cookie incompatibility with NFSv4 commit 44512449c0ab368889dd13ae0031fba74ee7e1d2 upstream. 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 Tested-by: Christian Kujau [bwh: Backported to 3.2: - Adjust context - s/ctx->pos/filp->f_pos/] Signed-off-by: Ben Hutchings --- fs/jfs/jfs_dtree.c | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-) (limited to 'fs') diff --git a/fs/jfs/jfs_dtree.c b/fs/jfs/jfs_dtree.c index 9197a1b0d02d..9f7c758761de 100644 --- a/fs/jfs/jfs_dtree.c +++ b/fs/jfs/jfs_dtree.c @@ -3047,6 +3047,14 @@ int jfs_readdir(struct file *filp, void *dirent, filldir_t filldir) dir_index = (u32) filp->f_pos; + /* + * NFSv4 reserves cookies 1 and 2 for . and .. so 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 *filp, void *dirent, filldir_t filldir) if (p->header.flag & BT_INTERNAL) { jfs_err("jfs_readdir: bad index table"); DT_PUTPAGE(mp); - filp->f_pos = -1; + filp->f_pos = DIREND; return 0; } } else { @@ -3094,7 +3102,7 @@ int jfs_readdir(struct file *filp, void *dirent, filldir_t filldir) /* * self "." */ - filp->f_pos = 0; + filp->f_pos = 1; if (filldir(dirent, ".", 1, 0, ip->i_ino, DT_DIR)) return 0; @@ -3102,7 +3110,7 @@ int jfs_readdir(struct file *filp, void *dirent, filldir_t filldir) /* * parent ".." */ - filp->f_pos = 1; + filp->f_pos = 2; if (filldir(dirent, "..", 2, 1, PARENT(ip), DT_DIR)) return 0; @@ -3123,24 +3131,25 @@ int jfs_readdir(struct file *filp, void *dirent, filldir_t filldir) /* * 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 = filp->f_pos; - if (dtpos == 0) { + if (dtpos < 2) { /* build "." entry */ + filp->f_pos = 1; if (filldir(dirent, ".", 1, filp->f_pos, ip->i_ino, DT_DIR)) return 0; - dtoffset->index = 1; + dtoffset->index = 2; filp->f_pos = dtpos; } if (dtoffset->pn == 0) { - if (dtoffset->index == 1) { + if (dtoffset->index == 2) { /* build ".." entry */ if (filldir(dirent, "..", 2, filp->f_pos, @@ -3233,6 +3242,12 @@ int jfs_readdir(struct file *filp, void *dirent, filldir_t filldir) } 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); -- cgit v1.2.3