diff options
| -rw-r--r-- | fs/fuse/file.c | 100 | ||||
| -rw-r--r-- | fs/fuse/fuse_i.h | 1 |
2 files changed, 91 insertions, 10 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index bf765cf7b11..f8ff019cc6e 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1414,7 +1414,9 @@ static void fuse_writepage_free(struct fuse_conn *fc, struct fuse_req *req) for (i = 0; i < req->num_pages; i++) __free_page(req->pages[i]); - fuse_file_put(req->ff, false); + + if (req->ff) + fuse_file_put(req->ff, false); } static void fuse_writepage_finish(struct fuse_conn *fc, struct fuse_req *req) @@ -1496,6 +1498,14 @@ static void fuse_writepage_end(struct fuse_conn *fc, struct fuse_req *req) mapping_set_error(inode->i_mapping, req->out.h.error); spin_lock(&fc->lock); + while (req->misc.write.next) { + struct fuse_req *next = req->misc.write.next; + req->misc.write.next = next->misc.write.next; + next->misc.write.next = NULL; + list_add(&next->writepages_entry, &fi->writepages); + list_add_tail(&next->list, &fi->queued_writes); + fuse_flush_writepages(inode); + } fi->writectr--; fuse_writepage_finish(fc, req); spin_unlock(&fc->lock); @@ -1548,6 +1558,7 @@ static int fuse_writepage_locked(struct page *page) copy_highpage(tmp_page, page); req->misc.write.in.write_flags |= FUSE_WRITE_CACHE; + req->misc.write.next = NULL; req->in.argpages = 1; req->num_pages = 1; req->pages[0] = tmp_page; @@ -1612,6 +1623,62 @@ static void fuse_writepages_send(struct fuse_fill_wb_data *data) end_page_writeback(data->orig_pages[i]); } +static bool fuse_writepage_in_flight(struct fuse_req *new_req, + struct page *page) +{ + struct fuse_conn *fc = get_fuse_conn(new_req->inode); + struct fuse_inode *fi = get_fuse_inode(new_req->inode); + struct fuse_req *tmp; + struct fuse_req *old_req; + bool found = false; + pgoff_t curr_index; + + BUG_ON(new_req->num_pages != 0); + + spin_lock(&fc->lock); + list_del(&new_req->writepages_entry); + new_req->num_pages = 1; + list_for_each_entry(old_req, &fi->writepages, writepages_entry) { + BUG_ON(old_req->inode != new_req->inode); + curr_index = old_req->misc.write.in.offset >> PAGE_CACHE_SHIFT; + if (curr_index <= page->index && + page->index < curr_index + old_req->num_pages) { + found = true; + break; + } + } + if (!found) + goto out_unlock; + + for (tmp = old_req; tmp != NULL; tmp = tmp->misc.write.next) { + BUG_ON(tmp->inode != new_req->inode); + curr_index = tmp->misc.write.in.offset >> PAGE_CACHE_SHIFT; + if (tmp->num_pages == 1 && + curr_index == page->index) { + old_req = tmp; + } + } + + if (old_req->num_pages == 1 && (old_req->state == FUSE_REQ_INIT || + old_req->state == FUSE_REQ_PENDING)) { + copy_highpage(old_req->pages[0], page); + spin_unlock(&fc->lock); + + dec_bdi_stat(page->mapping->backing_dev_info, BDI_WRITEBACK); + dec_zone_page_state(page, NR_WRITEBACK_TEMP); + fuse_writepage_free(fc, new_req); + fuse_request_free(new_req); + goto out; + } else { + new_req->misc.write.next = old_req->misc.write.next; + old_req->misc.write.next = new_req; + } +out_unlock: + spin_unlock(&fc->lock); +out: + return found; +} + static int fuse_writepages_fill(struct page *page, struct writeback_control *wbc, void *_data) { @@ -1620,6 +1687,7 @@ static int fuse_writepages_fill(struct page *page, struct inode *inode = data->inode; struct fuse_conn *fc = get_fuse_conn(inode); struct page *tmp_page; + bool is_writeback; int err; if (!data->ff) { @@ -1629,15 +1697,20 @@ static int fuse_writepages_fill(struct page *page, goto out_unlock; } - if (req) { - BUG_ON(!req->num_pages); - if (req->num_pages == FUSE_MAX_PAGES_PER_REQ || - (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_write || - data->orig_pages[req->num_pages - 1]->index + 1 != page->index) { + /* + * Being under writeback is unlikely but possible. For example direct + * read to an mmaped fuse file will set the page dirty twice; once when + * the pages are faulted with get_user_pages(), and then after the read + * completed. + */ + is_writeback = fuse_page_is_writeback(inode, page->index); - fuse_writepages_send(data); - data->req = NULL; - } + if (req && req->num_pages && + (is_writeback || req->num_pages == FUSE_MAX_PAGES_PER_REQ || + (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_write || + data->orig_pages[req->num_pages - 1]->index + 1 != page->index)) { + fuse_writepages_send(data); + data->req = NULL; } err = -ENOMEM; tmp_page = alloc_page(GFP_NOFS | __GFP_HIGHMEM); @@ -1669,6 +1742,7 @@ static int fuse_writepages_fill(struct page *page, fuse_write_fill(req, data->ff, page_offset(page), 0); req->misc.write.in.write_flags |= FUSE_WRITE_CACHE; + req->misc.write.next = NULL; req->in.argpages = 1; req->background = 1; req->num_pages = 0; @@ -1690,6 +1764,13 @@ static int fuse_writepages_fill(struct page *page, inc_bdi_stat(page->mapping->backing_dev_info, BDI_WRITEBACK); inc_zone_page_state(tmp_page, NR_WRITEBACK_TEMP); + + err = 0; + if (is_writeback && fuse_writepage_in_flight(req, page)) { + end_page_writeback(page); + data->req = NULL; + goto out_unlock; + } data->orig_pages[req->num_pages] = page; /* @@ -1700,7 +1781,6 @@ static int fuse_writepages_fill(struct page *page, req->num_pages++; spin_unlock(&fc->lock); - err = 0; out_unlock: unlock_page(page); diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h index 5b9e6f3b6ae..643274852c8 100644 --- a/fs/fuse/fuse_i.h +++ b/fs/fuse/fuse_i.h @@ -321,6 +321,7 @@ struct fuse_req { struct { struct fuse_write_in in; struct fuse_write_out out; + struct fuse_req *next; } write; struct fuse_notify_retrieve_in retrieve_in; struct fuse_lk_in lk_in; |