CIFS: Fix error paths in writeback code
This patch aims to address writeback code problems related to error
paths. In particular it respects EINTR and related error codes and
stores and returns the first error occurred during writeback.
Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 5b6f839..2c7689f 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -733,7 +733,8 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush)
if (can_flush) {
rc = filemap_write_and_wait(inode->i_mapping);
- mapping_set_error(inode->i_mapping, rc);
+ if (!is_interrupt_error(rc))
+ mapping_set_error(inode->i_mapping, rc);
if (tcon->unix_ext)
rc = cifs_get_inode_info_unix(&inode, full_path,
@@ -2118,6 +2119,7 @@ static int cifs_writepages(struct address_space *mapping,
pgoff_t end, index;
struct cifs_writedata *wdata;
int rc = 0;
+ int saved_rc = 0;
unsigned int xid;
/*
@@ -2146,8 +2148,10 @@ static int cifs_writepages(struct address_space *mapping,
rc = server->ops->wait_mtu_credits(server, cifs_sb->wsize,
&wsize, &credits);
- if (rc)
+ if (rc != 0) {
+ done = true;
break;
+ }
tofind = min((wsize / PAGE_SIZE) - 1, end - index) + 1;
@@ -2155,6 +2159,7 @@ static int cifs_writepages(struct address_space *mapping,
&found_pages);
if (!wdata) {
rc = -ENOMEM;
+ done = true;
add_credits_and_wake_if(server, credits, 0);
break;
}
@@ -2183,7 +2188,7 @@ static int cifs_writepages(struct address_space *mapping,
if (rc != 0) {
add_credits_and_wake_if(server, wdata->credits, 0);
for (i = 0; i < nr_pages; ++i) {
- if (rc == -EAGAIN)
+ if (is_retryable_error(rc))
redirty_page_for_writepage(wbc,
wdata->pages[i]);
else
@@ -2191,7 +2196,7 @@ static int cifs_writepages(struct address_space *mapping,
end_page_writeback(wdata->pages[i]);
put_page(wdata->pages[i]);
}
- if (rc != -EAGAIN)
+ if (!is_retryable_error(rc))
mapping_set_error(mapping, rc);
}
kref_put(&wdata->refcount, cifs_writedata_release);
@@ -2201,6 +2206,15 @@ static int cifs_writepages(struct address_space *mapping,
continue;
}
+ /* Return immediately if we received a signal during writing */
+ if (is_interrupt_error(rc)) {
+ done = true;
+ break;
+ }
+
+ if (rc != 0 && saved_rc == 0)
+ saved_rc = rc;
+
wbc->nr_to_write -= nr_pages;
if (wbc->nr_to_write <= 0)
done = true;
@@ -2218,6 +2232,9 @@ static int cifs_writepages(struct address_space *mapping,
goto retry;
}
+ if (saved_rc != 0)
+ rc = saved_rc;
+
if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
mapping->writeback_index = index;
@@ -2250,8 +2267,8 @@ cifs_writepage_locked(struct page *page, struct writeback_control *wbc)
set_page_writeback(page);
retry_write:
rc = cifs_partialpagewrite(page, 0, PAGE_SIZE);
- if (rc == -EAGAIN) {
- if (wbc->sync_mode == WB_SYNC_ALL)
+ if (is_retryable_error(rc)) {
+ if (wbc->sync_mode == WB_SYNC_ALL && rc == -EAGAIN)
goto retry_write;
redirty_page_for_writepage(wbc, page);
} else if (rc != 0) {