diff options
| -rw-r--r-- | fs/nfs/pagelist.c | 84 | ||||
| -rw-r--r-- | fs/nfs/write.c | 21 | ||||
| -rw-r--r-- | include/linux/nfs_page.h | 1 |
3 files changed, 77 insertions, 29 deletions
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index ba49192..be7cbce 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -116,7 +116,7 @@ __nfs_iocounter_wait(struct nfs_io_counter *c) if (atomic_read(&c->io_count) == 0) break; ret = nfs_wait_bit_killable(&q.key); - } while (atomic_read(&c->io_count) != 0); + } while (atomic_read(&c->io_count) != 0 && !ret); finish_wait(wq, &q.wait); return ret; } @@ -139,26 +139,49 @@ nfs_iocounter_wait(struct nfs_io_counter *c) /* * nfs_page_group_lock - lock the head of the page group * @req - request in group that is to be locked + * @nonblock - if true don't block waiting for lock * * this lock must be held if modifying the page group list * - * returns result from wait_on_bit_lock: 0 on success, < 0 on error + * return 0 on success, < 0 on error: -EDELAY if nonblocking or the + * result from wait_on_bit_lock + * + * NOTE: calling with nonblock=false should always have set the + * lock bit (see fs/buffer.c and other uses of wait_on_bit_lock + * with TASK_UNINTERRUPTIBLE), so there is no need to check the result. */ int -nfs_page_group_lock(struct nfs_page *req, bool wait) +nfs_page_group_lock(struct nfs_page *req, bool nonblock) { struct nfs_page *head = req->wb_head; - int ret; WARN_ON_ONCE(head != head->wb_head); - do { - ret = wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK, - TASK_UNINTERRUPTIBLE); - } while (wait && ret != 0); + if (!test_and_set_bit(PG_HEADLOCK, &head->wb_flags)) + return 0; - WARN_ON_ONCE(ret > 0); - return ret; + if (!nonblock) + return wait_on_bit_lock(&head->wb_flags, PG_HEADLOCK, + TASK_UNINTERRUPTIBLE); + + 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); } /* @@ -219,7 +242,7 @@ bool nfs_page_group_sync_on_bit(struct nfs_page *req, unsigned int bit) { bool ret; - nfs_page_group_lock(req, true); + nfs_page_group_lock(req, false); ret = nfs_page_group_sync_on_bit_locked(req, bit); nfs_page_group_unlock(req); @@ -701,10 +724,11 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc, struct nfs_pgio_header *hdr) { struct nfs_page *req; - struct page **pages; + struct page **pages, + *last_page; struct list_head *head = &desc->pg_list; struct nfs_commit_info cinfo; - unsigned int pagecount; + unsigned int pagecount, pageused; pagecount = nfs_page_array_len(desc->pg_base, desc->pg_count); if (!nfs_pgarray_set(&hdr->page_array, pagecount)) @@ -712,12 +736,23 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc, nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq); pages = hdr->page_array.pagevec; + last_page = NULL; + pageused = 0; while (!list_empty(head)) { req = nfs_list_entry(head->next); nfs_list_remove_request(req); nfs_list_add_request(req, &hdr->pages); - *pages++ = req->wb_page; + + if (WARN_ON_ONCE(pageused >= pagecount)) + return nfs_pgio_error(desc, hdr); + + if (!last_page || last_page != req->wb_page) { + *pages++ = last_page = req->wb_page; + pageused++; + } } + if (WARN_ON_ONCE(pageused != pagecount)) + return nfs_pgio_error(desc, hdr); if ((desc->pg_ioflags & FLUSH_COND_STABLE) && (desc->pg_moreio || nfs_reqs_to_commit(&cinfo))) @@ -788,6 +823,14 @@ static bool nfs_can_coalesce_requests(struct nfs_page *prev, return false; if (req_offset(req) != req_offset(prev) + prev->wb_bytes) return false; + if (req->wb_page == prev->wb_page) { + if (req->wb_pgbase != prev->wb_pgbase + prev->wb_bytes) + return false; + } else { + if (req->wb_pgbase != 0 || + prev->wb_pgbase + prev->wb_bytes != PAGE_CACHE_SIZE) + return false; + } } size = pgio->pg_ops->pg_test(pgio, prev, req); WARN_ON_ONCE(size > req->wb_bytes); @@ -858,13 +901,8 @@ static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, struct nfs_page *subreq; unsigned int bytes_left = 0; unsigned int offset, pgbase; - int ret; - ret = nfs_page_group_lock(req, false); - if (ret < 0) { - desc->pg_error = ret; - return 0; - } + nfs_page_group_lock(req, false); subreq = req; bytes_left = subreq->wb_bytes; @@ -886,11 +924,7 @@ static int __nfs_pageio_add_request(struct nfs_pageio_descriptor *desc, if (desc->pg_recoalesce) return 0; /* retry add_request for this subreq */ - ret = nfs_page_group_lock(req, false); - if (ret < 0) { - desc->pg_error = ret; - return 0; - } + nfs_page_group_lock(req, false); continue; } diff --git a/fs/nfs/write.c b/fs/nfs/write.c index e3b5cf2..175d5d0 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -241,7 +241,7 @@ static bool nfs_page_group_covers_page(struct nfs_page *req) unsigned int pos = 0; unsigned int len = nfs_page_length(req->wb_page); - nfs_page_group_lock(req, true); + nfs_page_group_lock(req, false); do { tmp = nfs_page_group_search_locked(req->wb_head, pos); @@ -478,10 +478,23 @@ try_again: return NULL; } - /* lock each request in the page group */ - ret = nfs_page_group_lock(head, false); - if (ret < 0) + /* 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 6ad2bbc..6c3e06e 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); |
