fuse_writepage_locked() should never submit new i/o for given page->index
if there is another one 'in progress' already. In most cases it's safe to
wait on page writeback. But if it was called due to memory shortage
(WB_SYNC_NONE), we should redirty page rather than blocking caller.
Signed-off-by: Maxim Patlasov <MPatlasov@xxxxxxxxxxxxx>
---
fs/fuse/file.c | 18 +++++++++++++++---
1 files changed, 15 insertions(+), 3 deletions(-)
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 3274708..4e4f6fd 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1370,7 +1370,8 @@ static struct fuse_file *fuse_write_file(struct fuse_conn *fc,
return ff;
}
-static int fuse_writepage_locked(struct page *page)
+static int fuse_writepage_locked(struct page *page,
+ struct writeback_control *wbc)
{
struct address_space *mapping = page->mapping;
struct inode *inode = mapping->host;
@@ -1379,6 +1380,14 @@ static int fuse_writepage_locked(struct page *page)
struct fuse_req *req;
struct page *tmp_page;
+ if (fuse_page_is_writeback(inode, page->index)) {
+ if (wbc->sync_mode != WB_SYNC_ALL) {
+ redirty_page_for_writepage(wbc, page);
+ return 0;
+ }
+ fuse_wait_on_page_writeback(inode, page->index);
+ }
+
set_page_writeback(page);
req = fuse_request_alloc_nofs();
@@ -1424,7 +1433,7 @@ static int fuse_writepage(struct page *page, struct writeback_control *wbc)
{
int err;
- err = fuse_writepage_locked(page);
+ err = fuse_writepage_locked(page, wbc);
unlock_page(page);
return err;
@@ -1678,7 +1687,10 @@ static int fuse_launder_page(struct page *page)
int err = 0;
if (clear_page_dirty_for_io(page)) {
struct inode *inode = page->mapping->host;
- err = fuse_writepage_locked(page);
+ struct writeback_control wbc = {
+ .sync_mode = WB_SYNC_ALL,
+ };
+ err = fuse_writepage_locked(page, &wbc);
if (!err)
fuse_wait_on_page_writeback(inode, page->index);
}
--
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