From bf1c6aca96c9d2f117dc7e590c2bc2304e7febe1 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Tue, 26 Jul 2011 11:30:43 -0700 Subject: [PATCH] ceph: protect d_parent access in ceph_d_revalidate Protect d_parent with d_lock. Carry a reference. Simplify the flow so that there is a single exit point and cleanup. Reviewed-by: Yehuda Sadeh Signed-off-by: Sage Weil --- fs/ceph/dir.c | 32 +++++++++++++++++--------------- 1 file changed, 17 insertions(+), 15 deletions(-) diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index ed296ec..31d27f8 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -1024,36 +1024,38 @@ static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry) */ static int ceph_d_revalidate(struct dentry *dentry, struct nameidata *nd) { + int valid = 0; struct inode *dir; if (nd && nd->flags & LOOKUP_RCU) return -ECHILD; - dir = dentry->d_parent->d_inode; - dout("d_revalidate %p '%.*s' inode %p offset %lld\n", dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode, ceph_dentry(dentry)->offset); + dir = ceph_get_dentry_parent_inode(dentry); + /* always trust cached snapped dentries, snapdir dentry */ if (ceph_snap(dir) != CEPH_NOSNAP) { dout("d_revalidate %p '%.*s' inode %p is SNAPPED\n", dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); - goto out_touch; + valid = 1; + } else if (dentry->d_inode && + ceph_snap(dentry->d_inode) == CEPH_SNAPDIR) { + valid = 1; + } else if (dentry_lease_is_valid(dentry) || + dir_lease_is_valid(dir, dentry)) { + valid = 1; } - if (dentry->d_inode && ceph_snap(dentry->d_inode) == CEPH_SNAPDIR) - goto out_touch; - if (dentry_lease_is_valid(dentry) || - dir_lease_is_valid(dir, dentry)) - goto out_touch; - - dout("d_revalidate %p invalid\n", dentry); - d_drop(dentry); - return 0; -out_touch: - ceph_dentry_lru_touch(dentry); - return 1; + dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid"); + if (valid) + ceph_dentry_lru_touch(dentry); + else + d_drop(dentry); + iput(dir); + return valid; } /* -- 2.7.4