diff options
Diffstat (limited to 'fs/nfs/write.c')
| -rw-r--r-- | fs/nfs/write.c | 29 |
1 files changed, 17 insertions, 12 deletions
diff --git a/fs/nfs/write.c b/fs/nfs/write.c index 1ca759719429..c940e615f5dc 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -383,7 +383,7 @@ nfs_unroll_locks_and_wait(struct inode *inode, struct nfs_page *head, int ret; /* relinquish all the locks successfully grabbed this run */ - for (tmp = head ; tmp != req; tmp = tmp->wb_this_page) + for (tmp = head->wb_this_page ; tmp != req; tmp = tmp->wb_this_page) nfs_unlock_request(tmp); WARN_ON_ONCE(test_bit(PG_TEARDOWN, &req->wb_flags)); @@ -395,7 +395,7 @@ nfs_unroll_locks_and_wait(struct inode *inode, struct nfs_page *head, spin_unlock(&inode->i_lock); /* release ref from nfs_page_find_head_request_locked */ - nfs_release_request(head); + nfs_unlock_and_release_request(head); ret = nfs_wait_on_request(req); nfs_release_request(req); @@ -484,10 +484,6 @@ nfs_lock_and_join_requests(struct page *page) int ret; try_again: - total_bytes = 0; - - WARN_ON_ONCE(destroy_list); - spin_lock(&inode->i_lock); /* @@ -502,6 +498,16 @@ try_again: return NULL; } + /* lock the page head first in order to avoid an ABBA inefficiency */ + if (!nfs_lock_request(head)) { + spin_unlock(&inode->i_lock); + ret = nfs_wait_on_request(head); + nfs_release_request(head); + if (ret < 0) + return ERR_PTR(ret); + goto try_again; + } + /* holding inode lock, so always make a non-blocking call to try the * page group lock */ ret = nfs_page_group_lock(head, true); @@ -509,13 +515,14 @@ try_again: spin_unlock(&inode->i_lock); nfs_page_group_lock_wait(head); - nfs_release_request(head); + nfs_unlock_and_release_request(head); goto try_again; } /* lock each request in the page group */ - subreq = head; - do { + total_bytes = head->wb_bytes; + for (subreq = head->wb_this_page; subreq != head; + subreq = subreq->wb_this_page) { /* * Subrequests are always contiguous, non overlapping * and in order - but may be repeated (mirrored writes). @@ -541,9 +548,7 @@ try_again: return ERR_PTR(ret); } - - subreq = subreq->wb_this_page; - } while (subreq != head); + } /* Now that all requests are locked, make sure they aren't on any list. * Commit list removal accounting is done after locks are dropped */ |