[GFS2] Fix a case where we didn't get unstuffing right

There was a bug in the unstuffing logic which caused a crash
under certain circumstances. This is now fixed.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 9 insertions, 9 deletions

diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index 39d03f3f2d54..1ccc26426821 100644
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -220,14 +220,14 @@ static int stuffed_readpage(struct gfs2_inode *ip, struct page *page)
         if (error)
                 return error;
 
-        kaddr = kmap(page);
+        kaddr = kmap_atomic(page, KM_USER0);
         memcpy((char *)kaddr,
                dibh->b_data + sizeof(struct gfs2_dinode),
                ip->i_di.di_size);
         memset((char *)kaddr + ip->i_di.di_size,
                0,
                PAGE_CACHE_SIZE - ip->i_di.di_size);
-        kunmap(page);
+        kunmap_atomic(page, KM_USER0);
 
         brelse(dibh);
 
@@ -240,9 +240,9 @@ static int zero_readpage(struct page *page)
 {
         void *kaddr;
 
-        kaddr = kmap(page);
+        kaddr = kmap_atomic(page, KM_USER0);
         memset(kaddr, 0, PAGE_CACHE_SIZE);
-        kunmap(page);
+        kunmap_atomic(page, KM_USER0);
 
         SetPageUptodate(page);
         unlock_page(page);
@@ -364,14 +364,14 @@ static int gfs2_prepare_write(struct file *file, struct page *page,
         if (gfs2_is_stuffed(ip)) {
                 if (end > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
                         error = gfs2_unstuff_dinode(ip, gfs2_unstuffer_page, page);
-                        if (error)
-                                goto out;
-                } else if (!PageUptodate(page)) {
+                        if (error == 0)
+                                goto prepare_write;
+                } else if (!PageUptodate(page))
                         error = stuffed_readpage(ip, page);
-                        goto out;
-                }
+                goto out;
         }
 
+prepare_write:
         error = block_prepare_write(page, from, to, gfs2_get_block);
 
 out: