CIFS: Fix error paths in writeback code

[ Upstream commit 9a66396f1857cc1de06f4f4771797315e1a4ea56 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 7a4fae0dc566488478d7a1c02e81d945ace34709..3736391992917292747d2e87dd3daba6cd496645 100644 (file)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1563,6 +1563,25 @@ 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 fce610f6cd24bd005759f9f6d7996367fc57c3d1..327a101f7894fb31a64869616a06b04dd002b172 100644 (file)
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2043,7 +2043,7 @@ 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]);
@@ -2052,7 +2052,7 @@ 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;
                }
@@ -2061,7 +2061,8 @@ 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 116f8af0384f5e2bee71947ec44ddd9825d70b6d..c13effbaadba5b1d0c21a17d9ff927a9e258bab7 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -732,7 +732,8 @@ 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,
@@ -2117,6 +2118,7 @@ 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;
 
        /*
@@ -2145,8 +2147,10 @@ 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;
 
@@ -2154,6 +2158,7 @@ retry:
                                                  &found_pages);
                if (!wdata) {
                        rc = -ENOMEM;
+                       done = true;
                        add_credits_and_wake_if(server, credits, 0);
                        break;
                }
@@ -2182,7 +2187,7 @@ 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
@@ -2190,7 +2195,7 @@ 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);
@@ -2200,6 +2205,15 @@ 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;
@@ -2217,6 +2231,9 @@ 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;
 
@@ -2249,8 +2266,8 @@ 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 a81a9df997c1c113e0c00e8d0695d46fc05060f6..84d51ca91ef7baade0876dd882192d36f2d59490 100644 (file)
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -2261,6 +2261,11 @@ 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;
 
@@ -2404,6 +2409,11 @@ 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;