Revert "LU-16046 revert: "LU-9964 llite: prevent mulitple group locks""

[fs/lustre-release.git] / lustre / llite / file.c

diff --git a/lustre/llite/file.c b/lustre/llite/file.c
index 86e55f4..a454902 100644 (file)
--- a/lustre/llite/file.c
+++ b/lustre/llite/file.c
@@ -2632,6 +2632,7 @@ out:
        RETURN(rc);
 }
 
+
 static int
 ll_get_grouplock(struct inode *inode, struct file *file, unsigned long arg)
 {
@@ -2647,18 +2648,28 @@ ll_get_grouplock(struct inode *inode, struct file *file, unsigned long arg)
                RETURN(-EINVAL);
        }
 
-        if (ll_file_nolock(file))
-                RETURN(-EOPNOTSUPP);
+       if (ll_file_nolock(file))
+               RETURN(-EOPNOTSUPP);
+retry:
+       if (file->f_flags & O_NONBLOCK) {
+               if (!mutex_trylock(&lli->lli_group_mutex))
+                       RETURN(-EAGAIN);
+       } else
+               mutex_lock(&lli->lli_group_mutex);
 
-       read_lock(&lli->lli_lock);
        if (fd->fd_flags & LL_FILE_GROUP_LOCKED) {
                CWARN("group lock already existed with gid %lu\n",
                      fd->fd_grouplock.lg_gid);
-               read_unlock(&lli->lli_lock);
-               RETURN(-EINVAL);
+               GOTO(out, rc = -EINVAL);
+       }
+       if (arg != lli->lli_group_gid && lli->lli_group_users != 0) {
+               if (file->f_flags & O_NONBLOCK)
+                       GOTO(out, rc = -EAGAIN);
+               mutex_unlock(&lli->lli_group_mutex);
+               wait_var_event(&lli->lli_group_users, !lli->lli_group_users);
+               GOTO(retry, rc = 0);
        }
        LASSERT(fd->fd_grouplock.lg_lock == NULL);
-       read_unlock(&lli->lli_lock);
 
        /**
         * XXX: group lock needs to protect all OST objects while PFL
@@ -2678,7 +2689,7 @@ ll_get_grouplock(struct inode *inode, struct file *file, unsigned long arg)
 
                env = cl_env_get(&refcheck);
                if (IS_ERR(env))
-                       RETURN(PTR_ERR(env));
+                       GOTO(out, rc = PTR_ERR(env));
 
                rc = cl_object_layout_get(env, obj, &cl);
                if (rc >= 0 && cl.cl_is_composite)
@@ -2687,28 +2698,26 @@ ll_get_grouplock(struct inode *inode, struct file *file, unsigned long arg)
 
                cl_env_put(env, &refcheck);
                if (rc < 0)
-                       RETURN(rc);
+                       GOTO(out, rc);
        }
 
        rc = cl_get_grouplock(ll_i2info(inode)->lli_clob,
                              arg, (file->f_flags & O_NONBLOCK), &grouplock);
-       if (rc)
-               RETURN(rc);
 
-       write_lock(&lli->lli_lock);
-       if (fd->fd_flags & LL_FILE_GROUP_LOCKED) {
-               write_unlock(&lli->lli_lock);
-               CERROR("another thread just won the race\n");
-               cl_put_grouplock(&grouplock);
-               RETURN(-EINVAL);
-       }
+       if (rc)
+               GOTO(out, rc);
 
        fd->fd_flags |= LL_FILE_GROUP_LOCKED;
        fd->fd_grouplock = grouplock;
-       write_unlock(&lli->lli_lock);
+       if (lli->lli_group_users == 0)
+               lli->lli_group_gid = grouplock.lg_gid;
+       lli->lli_group_users++;
 
        CDEBUG(D_INFO, "group lock %lu obtained\n", arg);
-       RETURN(0);
+out:
+       mutex_unlock(&lli->lli_group_mutex);
+
+       RETURN(rc);
 }
 
 static int ll_put_grouplock(struct inode *inode, struct file *file,
@@ -2717,32 +2726,40 @@ static int ll_put_grouplock(struct inode *inode, struct file *file,
        struct ll_inode_info   *lli = ll_i2info(inode);
        struct ll_file_data    *fd = file->private_data;
        struct ll_grouplock     grouplock;
+       int                     rc;
        ENTRY;
 
-       write_lock(&lli->lli_lock);
+       mutex_lock(&lli->lli_group_mutex);
        if (!(fd->fd_flags & LL_FILE_GROUP_LOCKED)) {
-               write_unlock(&lli->lli_lock);
-                CWARN("no group lock held\n");
-                RETURN(-EINVAL);
-        }
+               CWARN("no group lock held\n");
+               GOTO(out, rc = -EINVAL);
+       }
 
        LASSERT(fd->fd_grouplock.lg_lock != NULL);
 
        if (fd->fd_grouplock.lg_gid != arg) {
                CWARN("group lock %lu doesn't match current id %lu\n",
                      arg, fd->fd_grouplock.lg_gid);
-               write_unlock(&lli->lli_lock);
-               RETURN(-EINVAL);
+               GOTO(out, rc = -EINVAL);
        }
 
        grouplock = fd->fd_grouplock;
        memset(&fd->fd_grouplock, 0, sizeof(fd->fd_grouplock));
        fd->fd_flags &= ~LL_FILE_GROUP_LOCKED;
-       write_unlock(&lli->lli_lock);
 
        cl_put_grouplock(&grouplock);
+
+       lli->lli_group_users--;
+       if (lli->lli_group_users == 0) {
+               lli->lli_group_gid = 0;
+               wake_up_var(&lli->lli_group_users);
+       }
        CDEBUG(D_INFO, "group lock %lu released\n", arg);
-       RETURN(0);
+       GOTO(out, rc = 0);
+out:
+       mutex_unlock(&lli->lli_group_mutex);
+
+       RETURN(rc);
 }
 
 /**