[CIFS] Allow update of EOF on remote extend of file

Signed-off-by: Steve French <sfrench@us.ibm.com>

4 files changed, 11 insertions, 8 deletions

diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index f1f8225102f0..1108f17bf550 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -57,7 +57,7 @@ extern int SendReceiveBlockingLock(const unsigned int /* xid */ ,
                                 int * /* bytes returned */);
 extern int checkSMB(struct smb_hdr *smb, __u16 mid, unsigned int length);
 extern int is_valid_oplock_break(struct smb_hdr *smb, struct TCP_Server_Info *);
-extern int is_size_safe_to_change(struct cifsInodeInfo *);
+extern int is_size_safe_to_change(struct cifsInodeInfo *, __u64 eof);
 extern struct cifsFileInfo *find_writable_file(struct cifsInodeInfo *);
 extern unsigned int smbCalcSize(struct smb_hdr *ptr);
 extern unsigned int smbCalcSize_LE(struct smb_hdr *ptr);
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index e9dcf5ee29a2..07ff9351e9ee 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1954,7 +1954,7 @@ static int cifs_readpage(struct file *file, struct page *page)
    refreshing the inode only on increases in the file size 
    but this is tricky to do without racing with writebehind
    page caching in the current Linux kernel design */
-int is_size_safe_to_change(struct cifsInodeInfo *cifsInode)
+int is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
 {
         struct cifsFileInfo *open_file = NULL;
 
@@ -1976,6 +1976,9 @@ int is_size_safe_to_change(struct cifsInodeInfo *cifsInode)
                         return 1;
                 }
 
+                if(i_size_read(&cifsInode->vfs_inode) < end_of_file)
+                        return 1;
+
                 return 0;
         } else
                 return 1;
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index c4fa91b8b62f..3f5bc83dc3d1 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -140,7 +140,7 @@ int cifs_get_inode_info_unix(struct inode **pinode,
                 inode->i_gid = le64_to_cpu(findData.Gid);
                 inode->i_nlink = le64_to_cpu(findData.Nlinks);
 
-                if (is_size_safe_to_change(cifsInfo)) {
+                if (is_size_safe_to_change(cifsInfo, end_of_file)) {
                 /* can not safely change the file size here if the
                    client is writing to it due to potential races */
 
@@ -491,8 +491,8 @@ int cifs_get_inode_info(struct inode **pinode,
                 /* BB add code here -
                    validate if device or weird share or device type? */
                 }
-                if (is_size_safe_to_change(cifsInfo)) {
-                        /* can not safely change the file size here if the
+                if (is_size_safe_to_change(cifsInfo, le64_to_cpu(pfindData->EndOfFile))) {
+                        /* can not safely shrink the file size here if the
                            client is writing to it due to potential races */
                         i_size_write(inode,le64_to_cpu(pfindData->EndOfFile));
 
diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
index 782940be550f..c6220bd27165 100644
--- a/fs/cifs/readdir.c
+++ b/fs/cifs/readdir.c
@@ -222,7 +222,7 @@ static void fill_in_inode(struct inode *tmp_inode, int new_buf_type,
                 atomic_set(&cifsInfo->inUse, 1);
         }
 
-        if (is_size_safe_to_change(cifsInfo)) {
+        if (is_size_safe_to_change(cifsInfo, end_of_file)) {
                 /* can not safely change the file size here if the 
                 client is writing to it due to potential races */
                 i_size_write(tmp_inode, end_of_file);
@@ -351,10 +351,10 @@ static void unix_fill_in_inode(struct inode *tmp_inode,
         tmp_inode->i_gid = le64_to_cpu(pfindData->Gid);
         tmp_inode->i_nlink = le64_to_cpu(pfindData->Nlinks);
 
-        if (is_size_safe_to_change(cifsInfo)) {
+        if (is_size_safe_to_change(cifsInfo, end_of_file)) {
                 /* can not safely change the file size here if the 
                 client is writing to it due to potential races */
-                i_size_write(tmp_inode,end_of_file);
+                i_size_write(tmp_inode, end_of_file);
 
         /* 512 bytes (2**9) is the fake blocksize that must be used */
         /* for this calculation, not the real blocksize */