diff options
| -rw-r--r-- | fs/nfs/write.c | 40 |
1 files changed, 22 insertions, 18 deletions
diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 08c1ce968cce..ff7c90c7ff79 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -372,15 +372,14 @@ nfs_page_group_clear_bits(struct nfs_page *req) * @head - head request of page group, must be holding head lock * @req - request that couldn't lock and needs to wait on the req bit lock * - * NOTE: this must be called holding page_group bit lock and inode spin lock - * and BOTH will be released before returning. + * NOTE: this must be called holding page_group bit lock + * which will be released before returning. * * returns 0 on success, < 0 on error. */ static int nfs_unroll_locks_and_wait(struct inode *inode, struct nfs_page *head, struct nfs_page *req) - __releases(&inode->i_lock) { struct nfs_page *tmp; int ret; @@ -395,7 +394,6 @@ nfs_unroll_locks_and_wait(struct inode *inode, struct nfs_page *head, kref_get(&req->wb_kref); nfs_page_group_unlock(head); - spin_unlock(&inode->i_lock); /* release ref from nfs_page_find_head_request_locked */ nfs_unlock_and_release_request(head); @@ -491,8 +489,9 @@ nfs_lock_and_join_requests(struct page *page) int ret; try_again: + if (!(PagePrivate(page) || PageSwapCache(page))) + return NULL; spin_lock(&inode->i_lock); - /* * A reference is taken only on the head request which acts as a * reference to the whole page group - the group will not be destroyed @@ -514,16 +513,12 @@ try_again: return ERR_PTR(ret); goto try_again; } + spin_unlock(&inode->i_lock); - /* holding inode lock, so always make a non-blocking call to try the - * page group lock */ - ret = nfs_page_group_lock(head, true); + ret = nfs_page_group_lock(head, false); if (ret < 0) { - spin_unlock(&inode->i_lock); - - nfs_page_group_lock_wait(head); nfs_unlock_and_release_request(head); - goto try_again; + return ERR_PTR(ret); } /* lock each request in the page group */ @@ -531,8 +526,10 @@ try_again: for (subreq = head->wb_this_page; subreq != head; subreq = subreq->wb_this_page) { if (!nfs_lock_request(subreq)) { - /* releases page group bit lock and - * inode spin lock and all references */ + /* + * releases page group bit lock and + * page locks and all references + */ ret = nfs_unroll_locks_and_wait(inode, head, subreq); @@ -580,7 +577,9 @@ try_again: if (test_and_clear_bit(PG_REMOVE, &head->wb_flags)) { set_bit(PG_INODE_REF, &head->wb_flags); kref_get(&head->wb_kref); + spin_lock(&inode->i_lock); NFS_I(inode)->nrequests++; + spin_unlock(&inode->i_lock); } /* @@ -590,11 +589,14 @@ try_again: nfs_page_group_unlock(head); - /* drop lock to clean uprequests on destroy list */ - spin_unlock(&inode->i_lock); - nfs_destroy_unlinked_subrequests(destroy_list, head, inode); + /* Did we lose a race with nfs_inode_remove_request()? */ + if (!(PagePrivate(page) || PageSwapCache(page))) { + nfs_unlock_and_release_request(head); + return NULL; + } + /* still holds ref on head from nfs_page_find_head_request_locked * and still has lock on head from lock loop */ return head; @@ -968,7 +970,7 @@ nfs_clear_page_commit(struct page *page) WB_RECLAIMABLE); } -/* Called holding inode (/cinfo) lock */ +/* Called holding the request lock on @req */ static void nfs_clear_request_commit(struct nfs_page *req) { @@ -977,9 +979,11 @@ nfs_clear_request_commit(struct nfs_page *req) struct nfs_commit_info cinfo; nfs_init_cinfo_from_inode(&cinfo, inode); + spin_lock(&inode->i_lock); if (!pnfs_clear_request_commit(req, &cinfo)) { nfs_request_remove_commit_list(req, &cinfo); } + spin_unlock(&inode->i_lock); nfs_clear_page_commit(req->wb_page); } } |