diff options
| -rw-r--r-- | fs/exportfs/expfs.c | 45 |
1 files changed, 40 insertions, 5 deletions
diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index c65b748688ff..6b5ddd5492bc 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -90,6 +90,23 @@ find_disconnected_root(struct dentry *dentry) return dentry; } +static bool dentry_connected(struct dentry *dentry) +{ + dget(dentry); + while (dentry->d_flags & DCACHE_DISCONNECTED) { + struct dentry *parent = dget_parent(dentry); + + dput(dentry); + if (IS_ROOT(dentry)) { + dput(parent); + return false; + } + dentry = parent; + } + dput(dentry); + return true; +} + static void clear_disconnected(struct dentry *dentry) { dget(dentry); @@ -189,9 +206,9 @@ reconnect_path(struct vfsmount *mnt, struct dentry *target_dir, char *nbuf) dput(pd); if (err == -ENOENT) /* some race between get_parent and - * get_name? just try again + * get_name? */ - continue; + goto out_reconnected; break; } dprintk("%s: found name: %s\n", __func__, nbuf); @@ -211,12 +228,12 @@ reconnect_path(struct vfsmount *mnt, struct dentry *target_dir, char *nbuf) * hopefully, npd == pd, though it isn't really * a problem if it isn't */ + dput(npd); + dput(ppd); if (npd == pd) noprogress = 0; else - printk("%s: npd != pd\n", __func__); - dput(npd); - dput(ppd); + goto out_reconnected; if (IS_ROOT(pd)) { /* something went wrong, we have to give up */ dput(pd); @@ -234,6 +251,24 @@ reconnect_path(struct vfsmount *mnt, struct dentry *target_dir, char *nbuf) } return 0; +out_reconnected: + /* + * Someone must have renamed our entry into another parent, in + * which case it has been reconnected by the rename. + * + * Or someone removed it entirely, in which case filehandle + * lookup will succeed but the directory is now IS_DEAD and + * subsequent operations on it will fail. + * + * Alternatively, maybe there was no race at all, and the + * filesystem is just corrupt and gave us a parent that doesn't + * actually contain any entry pointing to this inode. So, + * double check that this worked and return -ESTALE if not: + */ + if (!dentry_connected(target_dir)) + return -ESTALE; + clear_disconnected(target_dir); + return 0; } struct getdents_callback { |