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-rw-r--r--fs/fuse/file.c100
-rw-r--r--fs/fuse/fuse_i.h1
2 files changed, 91 insertions, 10 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index bf765cf..f8ff019 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 5b9e6f3..6432748 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;
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