lockd: blocks should hold a reference to the nlm_file

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index c16c94f..ce754ef 100644 (file)
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -103,11 +103,10 @@ nlmsvc_remove_block(struct nlm_block *block)
 }
 
 /*
- * Find a block for a given lock and optionally remove it from
- * the list.
+ * Find a block for a given lock
  */
 static struct nlm_block *
-nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock, int remove)
+nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock)
 {
        struct nlm_block        **head, *block;
        struct file_lock        *fl;
@@ -124,10 +123,6 @@ nlmsvc_lookup_block(struct nlm_file *file, struct nlm_lock *lock, int remove)
                                (long long)fl->fl_end, fl->fl_type,
                                nlmdbg_cookie2a(&block->b_call->a_args.cookie));
                if (block->b_file == file && nlm_compare_locks(fl, &lock->fl)) {
-                       if (remove) {
-                               *head = block->b_next;
-                               block->b_queued = 0;
-                       }
                        kref_get(&block->b_count);
                        return block;
                }
@@ -213,6 +208,7 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_file *file,
        block->b_daemon = rqstp->rq_server;
        block->b_host   = host;
        block->b_file   = file;
+       file->f_count++;
 
        /* Add to file's list of blocks */
        block->b_fnext  = file->f_blocks;
@@ -257,6 +253,7 @@ static void nlmsvc_free_block(struct kref *kref)
 
        dprintk("lockd: freeing block %p...\n", block);
 
+       down(&file->f_sema);
        /* Remove block from file's list of blocks */
        for (bp = &file->f_blocks; *bp; bp = &(*bp)->b_fnext) {
                if (*bp == block) {
@@ -264,9 +261,11 @@ static void nlmsvc_free_block(struct kref *kref)
                        break;
                }
        }
+       up(&file->f_sema);
 
        nlmsvc_freegrantargs(block->b_call);
        nlm_release_call(block->b_call);
+       nlm_release_file(block->b_file);
        kfree(block);
 }
 
@@ -276,6 +275,36 @@ static void nlmsvc_release_block(struct nlm_block *block)
                kref_put(&block->b_count, nlmsvc_free_block);
 }
 
+static void nlmsvc_act_mark(struct nlm_host *host, struct nlm_file *file)
+{
+       struct nlm_block *block;
+
+       down(&file->f_sema);
+       for (block = file->f_blocks; block != NULL; block = block->b_fnext)
+               block->b_host->h_inuse = 1;
+       up(&file->f_sema);
+}
+
+static void nlmsvc_act_unlock(struct nlm_host *host, struct nlm_file *file)
+{
+       struct nlm_block *block;
+
+restart:
+       down(&file->f_sema);
+       for (block = file->f_blocks; block != NULL; block = block->b_fnext) {
+               if (host != NULL && host != block->b_host)
+                       continue;
+               if (!block->b_queued)
+                       continue;
+               kref_get(&block->b_count);
+               up(&file->f_sema);
+               nlmsvc_unlink_block(block);
+               nlmsvc_release_block(block);
+               goto restart;
+       }
+       up(&file->f_sema);
+}
+
 /*
  * Loop over all blocks and perform the action specified.
  * (NLM_ACT_CHECK handled by nlmsvc_inspect_file).
@@ -283,20 +312,10 @@ static void nlmsvc_release_block(struct nlm_block *block)
 int
 nlmsvc_traverse_blocks(struct nlm_host *host, struct nlm_file *file, int action)
 {
-       struct nlm_block        *block, *next;
-       /* XXX: Will everything get cleaned up if we don't unlock here? */
-
-       down(&file->f_sema);
-       for (block = file->f_blocks; block; block = next) {
-               next = block->b_fnext;
-               if (action == NLM_ACT_MARK)
-                       block->b_host->h_inuse = 1;
-               else if (action == NLM_ACT_UNLOCK) {
-                       if (host == NULL || host == block->b_host)
-                               nlmsvc_unlink_block(block);
-               }
-       }
-       up(&file->f_sema);
+       if (action == NLM_ACT_MARK)
+               nlmsvc_act_mark(host, file);
+       else
+               nlmsvc_act_unlock(host, file);
        return 0;
 }
 
@@ -358,7 +377,7 @@ again:
        /* Lock file against concurrent access */
        down(&file->f_sema);
        /* Get existing block (in case client is busy-waiting) */
-       block = nlmsvc_lookup_block(file, lock, 0);
+       block = nlmsvc_lookup_block(file, lock);
        if (block == NULL) {
                if (newblock != NULL)
                        lock = &newblock->b_call->a_args.lock;
@@ -491,11 +510,12 @@ nlmsvc_cancel_blocked(struct nlm_file *file, struct nlm_lock *lock)
                                (long long)lock->fl.fl_end);
 
        down(&file->f_sema);
-       if ((block = nlmsvc_lookup_block(file, lock, 1)) != NULL) {
+       block = nlmsvc_lookup_block(file, lock);
+       up(&file->f_sema);
+       if (block != NULL) {
                status = nlmsvc_unlink_block(block);
                nlmsvc_release_block(block);
        }
-       up(&file->f_sema);
        return status ? nlm_lck_denied : nlm_granted;
 }
 
@@ -553,9 +573,6 @@ nlmsvc_grant_blocked(struct nlm_block *block)
 
        dprintk("lockd: grant blocked lock %p\n", block);
 
-       /* First thing is lock the file */
-       down(&file->f_sema);
-
        /* Unlink block request from list */
        nlmsvc_unlink_block(block);
 
@@ -578,12 +595,12 @@ nlmsvc_grant_blocked(struct nlm_block *block)
        case -EAGAIN:
                dprintk("lockd: lock still blocked\n");
                nlmsvc_insert_block(block, NLM_NEVER);
-               goto out_unlock;
+               return;
        default:
                printk(KERN_WARNING "lockd: unexpected error %d in %s!\n",
                                -error, __FUNCTION__);
                nlmsvc_insert_block(block, 10 * HZ);
-               goto out_unlock;
+               return;
        }
 
 callback:
@@ -599,8 +616,6 @@ callback:
        if (nlm_async_call(block->b_call, NLMPROC_GRANTED_MSG,
                                                &nlmsvc_grant_ops) < 0)
                nlmsvc_release_block(block);
-out_unlock:
-       up(&file->f_sema);
 }
 
 /*
@@ -665,8 +680,6 @@ nlmsvc_grant_reply(struct svc_rqst *rqstp, struct nlm_cookie *cookie, u32 status
                return;
        file = block->b_file;
 
-       file->f_count++;
-       down(&file->f_sema);
        if (block) {
                if (status == NLM_LCK_DENIED_GRACE_PERIOD) {
                        /* Try again in a couple of seconds */
@@ -677,8 +690,6 @@ nlmsvc_grant_reply(struct svc_rqst *rqstp, struct nlm_cookie *cookie, u32 status
                        nlmsvc_unlink_block(block);
                }
        }
-       up(&file->f_sema);
-       nlm_release_file(file);
        nlmsvc_release_block(block);
 }