NFS: Fix issue with EIO on NFS read
The problem is that we may be caching writes that would extend the file and
create a hole in the region that we are reading. In this case, we need to
detect the eof from the server, ensure that we zero out the pages that
are part of the hole and mark them as up to date.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
(cherry picked from 856b603b01b99146918c093969b6cb1b1b0f1c01 commit)
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 65c0c5b..da9cf11 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -116,10 +116,17 @@
pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
base &= ~PAGE_CACHE_MASK;
pglen = PAGE_CACHE_SIZE - base;
- if (pglen < remainder)
+ for (;;) {
+ if (remainder <= pglen) {
+ memclear_highpage_flush(*pages, base, remainder);
+ break;
+ }
memclear_highpage_flush(*pages, base, pglen);
- else
- memclear_highpage_flush(*pages, base, remainder);
+ pages++;
+ remainder -= pglen;
+ pglen = PAGE_CACHE_SIZE;
+ base = 0;
+ }
}
/*
@@ -476,6 +483,8 @@
unsigned int base = data->args.pgbase;
struct page **pages;
+ if (data->res.eof)
+ count = data->args.count;
if (unlikely(count == 0))
return;
pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
@@ -483,11 +492,7 @@
count += base;
for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
SetPageUptodate(*pages);
- /*
- * Was this an eof or a short read? If the latter, don't mark the page
- * as uptodate yet.
- */
- if (count > 0 && (data->res.eof || data->args.count == data->res.count))
+ if (count != 0)
SetPageUptodate(*pages);
}
@@ -502,6 +507,8 @@
count += base;
for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
SetPageError(*pages);
+ if (count != 0)
+ SetPageError(*pages);
}
/*
