CIFS: Fix error paths in writeback code

BugLink: https://bugs.launchpad.net/bugs/1844558
[ 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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index edfa9e69fd100513dcdd6b6d24435c63149b69f5..e62586d9dfae2e7974c11ed413a5d80d1f66b91a 100644 (file)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1495,6 +1495,25 @@ 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 fa2a1da62a897a32d4f98f5ec612a6648209fdcd..a85c3a8dbadbc4b12e92e891a83f99501059b2f2 100644 (file)
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -2016,7 +2016,7 @@ 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]);
@@ -2025,7 +2025,7 @@ 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;
                }
@@ -2034,7 +2034,8 @@ 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 b0d3a520d77b0978e7e03eb0e8188257983fefcc..84867e6a11b4d6be13cdad2aa6942363e9aca8fa 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -749,7 +749,8 @@ 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,
@@ -2138,6 +2139,7 @@ static int cifs_writepages(struct address_space *mapping,
        pgoff_t end, index;
        struct cifs_writedata *wdata;
        int rc = 0;
+       int saved_rc = 0;
 
        /*
         * If wsize is smaller than the page cache size, default to writing
@@ -2164,8 +2166,10 @@ 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;
 
@@ -2173,6 +2177,7 @@ retry:
                                                  &found_pages);
                if (!wdata) {
                        rc = -ENOMEM;
+                       done = true;
                        add_credits_and_wake_if(server, credits, 0);
                        break;
                }
@@ -2201,7 +2206,7 @@ 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
@@ -2209,7 +2214,7 @@ 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);
@@ -2219,6 +2224,15 @@ 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;
@@ -2236,6 +2250,9 @@ 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;
 
@@ -2267,8 +2284,8 @@ 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 d4206e8fd1e5793b7cb0a215abb40751ccb2a7c9..452b30e46a63c61de0ba51a907613d4e5eae7b31 100644 (file)
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -2252,6 +2252,11 @@ 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;
 
@@ -2395,6 +2400,11 @@ 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;