lockd: blocks should hold a reference to the nlm_file

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

1 files changed, 46 insertions, 35 deletions

diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index c16c94f5a856..ce754efe2841 100644
--- 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);
 }