NFS: Fix up a race in the NFS implementation of GETLK

...and fix a memory corruption bug due to improper use of memcpy() on
 a struct file_lock.

 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Trond Myklebust 2005-10-18 14:20:16 -07:00
parent 06735b3454
commit 039c4d7a82

View file

@ -376,22 +376,31 @@ out_swapfile:
static int do_getlk(struct file *filp, int cmd, struct file_lock *fl) static int do_getlk(struct file *filp, int cmd, struct file_lock *fl)
{ {
struct file_lock *cfl;
struct inode *inode = filp->f_mapping->host; struct inode *inode = filp->f_mapping->host;
int status = 0; int status = 0;
lock_kernel(); lock_kernel();
/* Use local locking if mounted with "-onolock" */ /* Try local locking first */
if (!(NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)) cfl = posix_test_lock(filp, fl);
status = NFS_PROTO(inode)->lock(filp, cmd, fl); if (cfl != NULL) {
else { locks_copy_lock(fl, cfl);
struct file_lock *cfl = posix_test_lock(filp, fl); goto out;
fl->fl_type = F_UNLCK;
if (cfl != NULL)
memcpy(fl, cfl, sizeof(*fl));
} }
if (nfs_have_delegation(inode, FMODE_READ))
goto out_noconflict;
if (NFS_SERVER(inode)->flags & NFS_MOUNT_NONLM)
goto out_noconflict;
status = NFS_PROTO(inode)->lock(filp, cmd, fl);
out:
unlock_kernel(); unlock_kernel();
return status; return status;
out_noconflict:
fl->fl_type = F_UNLCK;
goto out;
} }
static int do_vfs_lock(struct file *file, struct file_lock *fl) static int do_vfs_lock(struct file *file, struct file_lock *fl)