From 8045e2985012bdb95d832dfbcceae1815880a6ed Mon Sep 17 00:00:00 2001 From: OGAWA Hirofumi Date: Tue, 12 Jan 2010 03:32:24 +0900 Subject: [PATCH] fat: Fix vfat_lookup() After d_find_alias(), vfat_lookup() checks !(->d_flags & DCACHE_DISCONNECTED) without IS_ROOT(). This means it hits non-anonymous but disconnected dentry. (NOTE: d_splice_alias() doesn't clear DCACHE_DISCONNECTED) But, vfat_lookup() has interest to alias if it was non-anonymous. So, this adds vfat_d_anon_disconn() helper to check it correctly. Another bug is refcnt leak. It needs dput() for uninterested alias. Signed-off-by: OGAWA Hirofumi --- fs/fat/namei_vfat.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c index f565f24019b5..411c192a05fa 100644 --- a/fs/fat/namei_vfat.c +++ b/fs/fat/namei_vfat.c @@ -701,6 +701,15 @@ static int vfat_find(struct inode *dir, struct qstr *qname, return fat_search_long(dir, qname->name, len, sinfo); } +/* + * (nfsd's) anonymous disconnected dentry? + * NOTE: !IS_ROOT() is not anonymous (I.e. d_splice_alias() did the job). + */ +static int vfat_d_anon_disconn(struct dentry *dentry) +{ + return IS_ROOT(dentry) && (dentry->d_flags & DCACHE_DISCONNECTED); +} + static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { @@ -729,11 +738,11 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry, } alias = d_find_alias(inode); - if (alias && !(alias->d_flags & DCACHE_DISCONNECTED)) { + if (alias && !vfat_d_anon_disconn(alias)) { /* - * This inode has non DCACHE_DISCONNECTED dentry. This - * means, the user did ->lookup() by an another name - * (longname vs 8.3 alias of it) in past. + * This inode has non anonymous-DCACHE_DISCONNECTED + * dentry. This means, the user did ->lookup() by an + * another name (longname vs 8.3 alias of it) in past. * * Switch to new one for reason of locality if possible. */ @@ -743,7 +752,9 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry, iput(inode); unlock_super(sb); return alias; - } + } else + dput(alias); + out: unlock_super(sb); dentry->d_op = sb->s_root->d_op; -- 2.39.2