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nfs4: treat lock owners as opaque values

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Do the following set of ops with a file on a NFSv4 mount:

    exec 3>>/file/on/nfsv4
    flock -x 3
    exec 3>&-

You'll see the LOCK request go across the wire, but no LOCKU when the
file is closed.

What happens is that the fd is passed across a fork, and the final close
is done in a different process than the opener. That makes
__nfs4_find_lock_state miss finding the correct lock state because it
uses the fl_pid as a search key. A new one is created, and the locking
code treats it as a delegation stateid (because NFS_LOCK_INITIALIZED
isn't set).

The root cause of this breakage seems to be commit 77041ed9b4
(NFSv4: Ensure the lockowners are labelled using the fl_owner and/or
fl_pid).

That changed it so that flock lockowners are allocated based on the
fl_pid. I think this is incorrect. flock locks should be "owned" by the
struct file, and that is already accounted for in the fl_owner field of
the lock request when it comes through nfs_flock.

This patch basically reverts the above commit and with it, a LOCKU is
sent in the above reproducer.

Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
Jeff Layton 2014-05-01 06:28:45 -04:00 committed by Trond Myklebust
parent 039b756a2d
commit 8003d3c4aa
2 changed files with 10 additions and 48 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

13
fs/nfs/nfs4_fs.h
View file

@ -129,17 +129,6 @@ enum {
* LOCK: one nfs4_state (LOCK) to hold the lock stateid nfs4_state(OPEN)
*/
struct nfs4_lock_owner {
unsigned int lo_type;
#define NFS4_ANY_LOCK_TYPE (0U)
#define NFS4_FLOCK_LOCK_TYPE (1U << 0)
#define NFS4_POSIX_LOCK_TYPE (1U << 1)
union {
fl_owner_t posix_owner;
pid_t flock_owner;
} lo_u;
};
struct nfs4_lock_state {
struct list_head ls_locks; /* Other lock stateids */
struct nfs4_state * ls_state; /* Pointer to open state */
@ -149,7 +138,7 @@ struct nfs4_lock_state {
struct nfs_seqid_counter ls_seqid;
nfs4_stateid ls_stateid;
atomic_t ls_count;
struct nfs4_lock_owner ls_owner;
fl_owner_t ls_owner;
};
/* bits for nfs4_state->flags */

45
fs/nfs/nfs4state.c
View file

@ -787,21 +787,12 @@ void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
* that is compatible with current->files
*/
static struct nfs4_lock_state *
__nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_pid, unsigned int type)
__nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
{
struct nfs4_lock_state *pos;
list_for_each_entry(pos, &state->lock_states, ls_locks) {
if (type != NFS4_ANY_LOCK_TYPE && pos->ls_owner.lo_type != type)
if (pos->ls_owner != fl_owner)
continue;
switch (pos->ls_owner.lo_type) {
case NFS4_POSIX_LOCK_TYPE:
if (pos->ls_owner.lo_u.posix_owner != fl_owner)
continue;
break;
case NFS4_FLOCK_LOCK_TYPE:
if (pos->ls_owner.lo_u.flock_owner != fl_pid)
continue;
}
atomic_inc(&pos->ls_count);
return pos;
}
@ -813,7 +804,7 @@ __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_p
* exists, return an uninitialized one.
*
*/
static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner, pid_t fl_pid, unsigned int type)
static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
{
struct nfs4_lock_state *lsp;
struct nfs_server *server = state->owner->so_server;
@ -824,17 +815,7 @@ static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, f
nfs4_init_seqid_counter(&lsp->ls_seqid);
atomic_set(&lsp->ls_count, 1);
lsp->ls_state = state;
lsp->ls_owner.lo_type = type;
switch (lsp->ls_owner.lo_type) {
case NFS4_FLOCK_LOCK_TYPE:
lsp->ls_owner.lo_u.flock_owner = fl_pid;
break;
case NFS4_POSIX_LOCK_TYPE:
lsp->ls_owner.lo_u.posix_owner = fl_owner;
break;
default:
goto out_free;
}
lsp->ls_owner = fl_owner;
lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
if (lsp->ls_seqid.owner_id < 0)
goto out_free;
@ -857,13 +838,13 @@ void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp
* exists, return an uninitialized one.
*
*/
static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner, pid_t pid, unsigned int type)
static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
{
struct nfs4_lock_state *lsp, *new = NULL;
for(;;) {
spin_lock(&state->state_lock);
lsp = __nfs4_find_lock_state(state, owner, pid, type);
lsp = __nfs4_find_lock_state(state, owner);
if (lsp != NULL)
break;
if (new != NULL) {
@ -874,7 +855,7 @@ static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_
break;
}
spin_unlock(&state->state_lock);
new = nfs4_alloc_lock_state(state, owner, pid, type);
new = nfs4_alloc_lock_state(state, owner);
if (new == NULL)
return NULL;
}
@ -935,13 +916,7 @@ int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
if (fl->fl_ops != NULL)
return 0;
if (fl->fl_flags & FL_POSIX)
lsp = nfs4_get_lock_state(state, fl->fl_owner, 0, NFS4_POSIX_LOCK_TYPE);
else if (fl->fl_flags & FL_FLOCK)
lsp = nfs4_get_lock_state(state, NULL, fl->fl_pid,
NFS4_FLOCK_LOCK_TYPE);
else
return -EINVAL;
lsp = nfs4_get_lock_state(state, fl->fl_owner);
if (lsp == NULL)
return -ENOMEM;
fl->fl_u.nfs4_fl.owner = lsp;
@ -955,7 +930,6 @@ static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
{
struct nfs4_lock_state *lsp;
fl_owner_t fl_owner;
pid_t fl_pid;
int ret = -ENOENT;
@ -966,9 +940,8 @@ static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
goto out;
fl_owner = lockowner->l_owner;
fl_pid = lockowner->l_pid;
spin_lock(&state->state_lock);
lsp = __nfs4_find_lock_state(state, fl_owner, fl_pid, NFS4_ANY_LOCK_TYPE);
lsp = __nfs4_find_lock_state(state, fl_owner);
if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
ret = -EIO;
else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {