From: Pavel Shilovsky <pshilov@microsoft.com>
Date: Tue, 8 Jan 2019 11:15:28 -0800
Subject: [PATCH] CIFS: Fix error paths in writeback code
Git-commit: 9a66396f1857cc1de06f4f4771797315e1a4ea56
Patch-mainline: v5.0-rc2
References: bsc#1144333
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>
Acked-by: Aurelien Aptel <aaptel@suse.com>
---
fs/cifs/cifsglob.h | 19 +++++++++++++++++++
fs/cifs/cifssmb.c | 7 ++++---
fs/cifs/file.c | 29 +++++++++++++++++++++++------
fs/cifs/inode.c | 10 ++++++++++
4 files changed, 56 insertions(+), 9 deletions(-)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 770926877b7c..94dbdbe5be34 100644
--- 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 332f88d753d1..e18915415e13 100644
--- 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 5b6f8392d9db..2c7689f3998d 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) {
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 13fb59aadebc..478003644916 100644
--- 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;
--
2.16.4