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authorTrond Myklebust <Trond.Myklebust@netapp.com>2009-06-17 13:23:00 -0700
committerTrond Myklebust <Trond.Myklebust@netapp.com>2009-06-17 13:23:00 -0700
commit3f09df70e3a33590ae5a97b8a15486d3711c7065 (patch)
tree18f5c9115aa79dd2cab5f87d7024bea5460ca0af /fs/nfs
parent965b5d679146c9f69bc0325388bb9ed357863c4f (diff)
NFS: Ensure we always hold the BKL when dereferencing inode->i_flock
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs')
-rw-r--r--fs/nfs/delegation.c16
-rw-r--r--fs/nfs/nfs4state.c9
2 files changed, 23 insertions, 2 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c
index d4f669f0683..af05b918cb5 100644
--- a/fs/nfs/delegation.c
+++ b/fs/nfs/delegation.c
@@ -70,15 +70,24 @@ static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_
struct file_lock *fl;
int status = 0;
+ if (inode->i_flock == NULL)
+ goto out;
+
+ /* 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) != ctx)
continue;
+ unlock_kernel();
status = nfs4_lock_delegation_recall(state, fl);
if (status < 0)
- break;
+ goto out;
+ lock_kernel();
}
+ unlock_kernel();
+out:
return status;
}
@@ -256,7 +265,10 @@ static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegat
struct nfs_inode *nfsi = NFS_I(inode);
nfs_msync_inode(inode);
- /* Guard against new delegated open calls */
+ /*
+ * Guard against new delegated open/lock/unlock calls and against
+ * state recovery
+ */
down_write(&nfsi->rwsem);
nfs_delegation_claim_opens(inode, &delegation->stateid);
up_write(&nfsi->rwsem);
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 6e094e95cf0..0b2a19bfe5a 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -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;