Re: [PATCH 004 of 19] knfsd: lockd: introduce nsm_handle

Neil Brown
2006-09-01T23:48:52Z

On Thursday August 31, akpm@osdl.org wrote:
> On Fri, 1 Sep 2006 14:38:25 +1000
> NeilBrown <neilb@suse.de> wrote:
>
> > +static DECLARE_MUTEX(nsm_sema);
> > ...
> > + down(&nsm_sema);
>
> Next you'll all be wearing bell-bottomed jeans?

You've been peeking in my wardrobe, haven't you :-)

NeilBrown

---
Subject: Convert lockd to use the newer mutex instead of the older semaphore

Both the (recently introduces) nsm_sema and the older f_sema are
converted over.

Cc: Olaf Kirch <okir@suse.de>
Signed-off-by: Neil Brown <neilb@suse.de>

### Diffstat output
./fs/lockd/host.c | 11 ++++++-----
./fs/lockd/svclock.c | 22 +++++++++++-----------
./fs/lockd/svcsubs.c | 2 +-
./include/linux/lockd/lockd.h | 2 +-
4 files changed, 19 insertions(+), 18 deletions(-)

diff .prev/fs/lockd/host.c ./fs/lockd/host.c
--- .prev/fs/lockd/host.c 2006-09-01 12:26:45.000000000 +1000
+++ ./fs/lockd/host.c 2006-09-01 18:56:39.000000000 +1000
@@ -436,7 +436,7 @@ nlm_gc_hosts(void)
* Manage NSM handles
*/
static LIST_HEAD(nsm_handles);
-static DECLARE_MUTEX(nsm_sema);
+static DEFINE_MUTEX(nsm_mutex);

static struct nsm_handle *
__nsm_find(const struct sockaddr_in *sin,
@@ -458,7 +458,7 @@ __nsm_find(const struct sockaddr_in *sin
return NULL;
}

- down(&nsm_sema);
+ mutex_lock(&nsm_mutex);
list_for_each(pos, &nsm_handles) {
nsm = list_entry(pos, struct nsm_handle, sm_link);

@@ -488,7 +488,8 @@ __nsm_find(const struct sockaddr_in *sin
list_add(&nsm->sm_link, &nsm_handles);
}

-out: up(&nsm_sema);
+out:
+ mutex_unlock(&nsm_mutex);
return nsm;
}

@@ -507,11 +508,11 @@ nsm_release(struct nsm_handle *nsm)
if (!nsm)
return;
if (atomic_read(&nsm->sm_count) == 1) {
- down(&nsm_sema);
+ mutex_lock(&nsm_mutex);
if (atomic_dec_and_test(&nsm->sm_count)) {
list_del(&nsm->sm_link);
kfree(nsm);
}
- up(&nsm_sema);
+ mutex_unlock(&nsm_mutex);
}
}

diff .prev/fs/lockd/svclock.c ./fs/lockd/svclock.c
--- .prev/fs/lockd/svclock.c 2006-09-01 12:17:21.000000000 +1000
+++ ./fs/lockd/svclock.c 2006-09-01 18:54:53.000000000 +1000
@@ -254,9 +254,9 @@ static void nlmsvc_free_block(struct kre
dprintk("lockd: freeing block %p...\n", block);

/* Remove block from file's list of blocks */
- down(&file->f_sema);
+ mutex_lock(&file->f_mutex);
list_del_init(&block->b_flist);
- up(&file->f_sema);
+ mutex_unlock(&file->f_mutex);

nlmsvc_freegrantargs(block->b_call);
nlm_release_call(block->b_call);
@@ -281,7 +281,7 @@ void nlmsvc_traverse_blocks(struct nlm_h
struct nlm_block *block, *next;

restart:
- down(&file->f_sema);
+ mutex_lock(&file->f_mutex);
list_for_each_entry_safe(block, next, &file->f_blocks, b_flist) {
if (!match(block->b_host, host))
continue;
@@ -290,12 +290,12 @@ restart:
if (list_empty(&block->b_list))
continue;
kref_get(&block->b_count);
- up(&file->f_sema);
+ mutex_unlock(&file->f_mutex);
nlmsvc_unlink_block(block);
nlmsvc_release_block(block);
goto restart;
}
- up(&file->f_sema);
+ mutex_unlock(&file->f_mutex);
}

/*
@@ -354,7 +354,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, stru
lock->fl.fl_flags &= ~FL_SLEEP;
again:
/* Lock file against concurrent access */
- down(&file->f_sema);
+ mutex_lock(&file->f_mutex);
/* Get existing block (in case client is busy-waiting) */
block = nlmsvc_lookup_block(file, lock);
if (block == NULL) {
@@ -392,10 +392,10 @@ again:

/* If we don't have a block, create and initialize it. Then
* retry because we may have slept in kmalloc. */
- /* We have to release f_sema as nlmsvc_create_block may try to
+ /* We have to release f_mutex as nlmsvc_create_block may try to
* to claim it while doing host garbage collection */
if (newblock == NULL) {
- up(&file->f_sema);
+ mutex_unlock(&file->f_mutex);
dprintk("lockd: blocking on this lock (allocating).\n");
if (!(newblock = nlmsvc_create_block(rqstp, file, lock, cookie)))
return nlm_lck_denied_nolocks;
@@ -405,7 +405,7 @@ again:
/* Append to list of blocked */
nlmsvc_insert_block(newblock, NLM_NEVER);
out:
- up(&file->f_sema);
+ mutex_unlock(&file->f_mutex);
nlmsvc_release_block(newblock);
nlmsvc_release_block(block);
dprintk("lockd: nlmsvc_lock returned %u\n", ret);
@@ -489,9 +489,9 @@ nlmsvc_cancel_blocked(struct nlm_file *f
(long long)lock->fl.fl_start,
(long long)lock->fl.fl_end);

- down(&file->f_sema);
+ mutex_lock(&file->f_mutex);
block = nlmsvc_lookup_block(file, lock);
- up(&file->f_sema);
+ mutex_unlock(&file->f_mutex);
if (block != NULL) {
status = nlmsvc_unlink_block(block);
nlmsvc_release_block(block);

diff .prev/fs/lockd/svcsubs.c ./fs/lockd/svcsubs.c
--- .prev/fs/lockd/svcsubs.c 2006-09-01 11:38:14.000000000 +1000
+++ ./fs/lockd/svcsubs.c 2006-09-01 18:55:56.000000000 +1000
@@ -106,7 +106,7 @@ nlm_lookup_file(struct svc_rqst *rqstp,
goto out_unlock;

memcpy(&file->f_handle, f, sizeof(struct nfs_fh));
- init_MUTEX(&file->f_sema);
+ mutex_init(&file->f_mutex);
INIT_HLIST_NODE(&file->f_list);
INIT_LIST_HEAD(&file->f_blocks);

diff .prev/include/linux/lockd/lockd.h ./include/linux/lockd/lockd.h
--- .prev/include/linux/lockd/lockd.h 2006-09-01 12:26:43.000000000 +1000
+++ ./include/linux/lockd/lockd.h 2006-09-01 18:50:32.000000000 +1000
@@ -111,7 +111,7 @@ struct nlm_file {
struct list_head f_blocks; /* blocked locks */
unsigned int f_locks; /* guesstimate # of locks */
unsigned int f_count; /* reference count */
- struct semaphore f_sema; /* avoid concurrent access */
+ struct mutex f_mutex; /* avoid concurrent access */
};

/*

--
VGER BF report: H 2.88825e-13