NFS: Ensure we always hold the BKL when dereferencing inode->i_flock

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust
2009-06-17 13:23:00 -07:00
parent 965b5d6791
commit 3f09df70e3
2 changed files with 23 additions and 2 deletions

View File

@@ -847,12 +847,19 @@ static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_
struct file_lock *fl;
int status = 0;
if (inode->i_flock == NULL)
return 0;
/* Guard against delegation returns and new lock/unlock calls */
down_write(&nfsi->rwsem);
/* Protect inode->i_flock using the BKL */
lock_kernel();
for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
continue;
if (nfs_file_open_context(fl->fl_file)->state != state)
continue;
unlock_kernel();
status = ops->recover_lock(state, fl);
switch (status) {
case 0:
@@ -875,7 +882,9 @@ static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_
/* kill_proc(fl->fl_pid, SIGLOST, 1); */
status = 0;
}
lock_kernel();
}
unlock_kernel();
out:
up_write(&nfsi->rwsem);
return status;