If CIFSSMBWrite2 returns -EAGAIN, then the error should be considered
temporary. CIFS should retry the write instead of setting an error on
the mapping and returning.
For WB_SYNC_ALL, just retry the write immediately. In the WB_SYNC_NONE
case, call redirty_page_for_writeback on all of the pages that didn't
get written out and then move on.
Also, fix up the handling of a short write with a successful return
code. MS-CIFS says that 0 bytes_written means ENOSPC or EFBIG. It
doesn't mention what a short, but non-zero write means, so for now
treat it as we would an -EAGAIN return.
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/cifs/file.c | 48 ++++++++++++++++++++++++++++++++++++------------
1 files changed, 36 insertions(+), 12 deletions(-)
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index fe16f6d..8bef611 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1430,6 +1430,7 @@ retry:
break;
}
if (n_iov) {
+retry_write:
open_file = find_writable_file(CIFS_I(mapping->host),
false);
if (!open_file) {
@@ -1442,31 +1443,54 @@ retry:
&bytes_written, iov, n_iov,
long_op);
cifsFileInfo_put(open_file);
- cifs_update_eof(cifsi, offset, bytes_written);
}
- if (rc || bytes_written < bytes_to_write) {
- cERROR(1, "Write2 ret %d, wrote %d",
- rc, bytes_written);
- mapping_set_error(mapping, rc);
- } else {
+ cFYI(1, "Write2 rc=%d, wrote=%u", rc, bytes_written);
+
+ /*
+ * For now, treat a short write as if nothing got
+ * written. A zero length write however indicates
+ * ENOSPC or EFBIG. We have no way to know which
+ * though, so call it ENOSPC for now. EFBIG would
+ * get translated to AS_EIO anyway.
+ *
+ * FIXME: make it take into account the data that did
+ * get written
+ */
+ if (rc == 0) {
+ if (bytes_written == 0)
+ rc = -ENOSPC;
+ else if (bytes_written < bytes_to_write)
+ rc = -EAGAIN;
+ }
+
+ /* retry on data-integrity flush */
+ if (wbc->sync_mode == WB_SYNC_ALL &&
+ (rc == -EAGAIN || bytes_written < bytes_to_write))
+ goto retry_write;
+
+ /* fix the stats and EOF */
+ if (bytes_written > 0) {
cifs_stats_bytes_written(tcon, bytes_written);
+ cifs_update_eof(cifsi, offset, bytes_written);
}
for (i = 0; i < n_iov; i++) {
page = pvec.pages[first + i];
- /* Should we also set page error on
- success rc but too little data written? */
- /* BB investigate retry logic on temporary
- server crash cases and how recovery works
- when page marked as error */
- if (rc)
+ /* on retryable write error, redirty page */
+ if (rc == -EAGAIN)
+ redirty_page_for_writepage(wbc, page);
+ else if (rc != 0)
SetPageError(page);
kunmap(page);
unlock_page(page);
end_page_writeback(page);
page_cache_release(page);
}
+
+ if (rc != -EAGAIN)
+ mapping_set_error(mapping, rc);
+
if ((wbc->nr_to_write -= n_iov) <= 0)
done = 1;
index = next;
--
1.7.3.2
--
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