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/cifsglob.h b/fs/cifs/cifsglob.h
index 770926877b7ce029690f8aeb9a4c352632c2bcd2..94dbdbe5be3458421568200d16d0a19652ae1161 100644 (file)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1575,6 +1575,25 @@ static inline void free_dfs_info_array(struct dfs_info3_param *param,
        kfree(param);
 }
 
+static inline bool is_interrupt_error(int error)
+{
+       switch (error) {
+       case -EINTR:
+       case -ERESTARTSYS:
+       case -ERESTARTNOHAND:
+       case -ERESTARTNOINTR:
+               return true;
+       }
+       return false;
+}
+
+static inline bool is_retryable_error(int error)
+{
+       if (is_interrupt_error(error) || error == -EAGAIN)
+               return true;
+       return false;
+}
+
 #define   MID_FREE 0
 #define   MID_REQUEST_ALLOCATED 1
 #define   MID_REQUEST_SUBMITTED 2

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 332f88d753d15f4ede47f4b501351a85e84ca1a5..e18915415e1337dc22e5fca260e9011ac5b1a37e 100644 (file)
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2123,7 +2123,7 @@ cifs_writev_requeue(struct cifs_writedata *wdata)
 
                for (j = 0; j < nr_pages; j++) {
                        unlock_page(wdata2->pages[j]);
-                       if (rc != 0 && rc != -EAGAIN) {
+                       if (rc != 0 && !is_retryable_error(rc)) {
                                SetPageError(wdata2->pages[j]);
                                end_page_writeback(wdata2->pages[j]);
                                put_page(wdata2->pages[j]);
@@ -2132,7 +2132,7 @@ cifs_writev_requeue(struct cifs_writedata *wdata)
 
                if (rc) {
                        kref_put(&wdata2->refcount, cifs_writedata_release);
-                       if (rc == -EAGAIN)
+                       if (is_retryable_error(rc))
                                continue;
                        break;
                }
@@ -2141,7 +2141,8 @@ cifs_writev_requeue(struct cifs_writedata *wdata)
                i += nr_pages;
        } while (i < wdata->nr_pages);
 
-       mapping_set_error(inode->i_mapping, rc);
+       if (rc != 0 && !is_retryable_error(rc))
+               mapping_set_error(inode->i_mapping, rc);
        kref_put(&wdata->refcount, cifs_writedata_release);
 }
 

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 5b6f8392d9db415501ba4a3ec68480ffdc571acb..2c7689f3998d175bae8886da89ea9c389b5b3ab8 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -733,7 +733,8 @@ reopen_success:
 
        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 @@ retry:
 
                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 @@ retry:
                                                  &found_pages);
                if (!wdata) {
                        rc = -ENOMEM;
+                       done = true;
                        add_credits_and_wake_if(server, credits, 0);
                        break;
                }
@@ -2183,7 +2188,7 @@ retry:
                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 @@ retry:
                                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 @@ retry:
                        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 @@ retry:
                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) {

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 13fb59aadebcb2ee4c558457273f7f945fe619f5..4780036449160c1a6aec70fd28bc5db28a4697f8 100644 (file)
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -2257,6 +2257,11 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
         * the flush returns error?
         */
        rc = filemap_write_and_wait(inode->i_mapping);
+       if (is_interrupt_error(rc)) {
+               rc = -ERESTARTSYS;
+               goto out;
+       }
+
        mapping_set_error(inode->i_mapping, rc);
        rc = 0;
 
@@ -2400,6 +2405,11 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
         * the flush returns error?
         */
        rc = filemap_write_and_wait(inode->i_mapping);
+       if (is_interrupt_error(rc)) {
+               rc = -ERESTARTSYS;
+               goto cifs_setattr_exit;
+       }
+
        mapping_set_error(inode->i_mapping, rc);
        rc = 0;