diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 30c9626f96b071bd6b7a1fe2de8588d844469528..4ec67f8d70aa300c528829f4b2dfd55a9203c35c 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -167,6 +167,23 @@ nfs_page_group_lock(struct nfs_page *req, bool nonblock) return -EAGAIN; } +/* + * nfs_page_group_lock_wait - wait for the lock to clear, but don't grab it + * @req - a request in the group + * + * This is a blocking call to wait for the group lock to be cleared. + */ +void +nfs_page_group_lock_wait(struct nfs_page *req) +{ + struct nfs_page *head = req->wb_head; + + WARN_ON_ONCE(head != head->wb_head); + + wait_on_bit(&head->wb_flags, PG_HEADLOCK, + TASK_UNINTERRUPTIBLE); +} + /* * nfs_page_group_unlock - unlock the head of the page group * @req - request in group that is to be unlocked diff --git a/fs/nfs/write.c b/fs/nfs/write.c index e056f617adf2f927bcc86b8cda118479a9588bee..175d5d073ccf350db485daf81ab3030555d80a60 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -478,13 +478,23 @@ nfs_lock_and_join_requests(struct page *page, bool nonblock) return NULL; } - /* lock each request in the page group */ + /* holding inode lock, so always make a non-blocking call to try the + * page group lock */ ret = nfs_page_group_lock(head, true); if (ret < 0) { spin_unlock(&inode->i_lock); + + if (!nonblock && ret == -EAGAIN) { + nfs_page_group_lock_wait(head); + nfs_release_request(head); + goto try_again; + } + nfs_release_request(head); return ERR_PTR(ret); } + + /* lock each request in the page group */ subreq = head; do { /* diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h index 6ad2bbcad4050c12105778c3011b5196fcbf4b9e..6c3e06ee2fb7af63cc5a87314baec589631619af 100644 --- a/include/linux/nfs_page.h +++ b/include/linux/nfs_page.h @@ -123,6 +123,7 @@ extern int nfs_wait_on_request(struct nfs_page *); extern void nfs_unlock_request(struct nfs_page *req); extern void nfs_unlock_and_release_request(struct nfs_page *); extern int nfs_page_group_lock(struct nfs_page *, bool); +extern void nfs_page_group_lock_wait(struct nfs_page *); extern void nfs_page_group_unlock(struct nfs_page *); extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int);