fs/9p: Fix inode i_size update in file_write

Only update inode i_size when we write towards end of file.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 98c4307a1f03..3cff25e759ec 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -440,6 +440,7 @@ v9fs_file_write_internal(struct inode *inode, struct p9_fid *fid,
                          loff_t *offset, int invalidate)
 {
         int n;
+        loff_t i_size;
         size_t total = 0;
         struct p9_client *clnt;
         loff_t origin = *offset;
@@ -464,8 +465,11 @@ v9fs_file_write_internal(struct inode *inode, struct p9_fid *fid,
                         invalidate_inode_pages2_range(inode->i_mapping,
                                                       pg_start, pg_end);
                 *offset += total;
-                i_size_write(inode, i_size_read(inode) + total);
-                inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
+                i_size = i_size_read(inode);
+                if (*offset > i_size) {
+                        inode_add_bytes(inode, *offset - i_size);
+                        i_size_write(inode, *offset);
+                }
         }
         if (n < 0)
                 return n;