Allow setting per-file compression via SMB2/3

Allow cifs/smb2/smb3 to return whether or not a file is compressed
via lsattr, and allow SMB2/SMB3 to set the per-file compression
flag ("chattr +c filename" on an smb3 mount).

Windows users often set the compressed flag (it can be
done from the desktop and file manager).  David Disseldorp
has patches to Samba server to support this (at least on btrfs)
which are complementary to this

Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 37 insertions, 18 deletions

diff --git a/fs/cifs/ioctl.c b/fs/cifs/ioctl.c
index 3e0845585853..029867078aff 100644
--- a/fs/cifs/ioctl.c
+++ b/fs/cifs/ioctl.c
@@ -3,7 +3,7 @@
  *
  *   vfs operations that deal with io control
  *
- *   Copyright (C) International Business Machines  Corp., 2005,2007
+ *   Copyright (C) International Business Machines  Corp., 2005,2013
  *   Author(s): Steve French (sfrench@us.ibm.com)
  *
  *   This library is free software; you can redistribute it and/or modify
@@ -34,13 +34,11 @@ long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
         int rc = -ENOTTY; /* strange error - but the precedent */
         unsigned int xid;
         struct cifs_sb_info *cifs_sb;
-#ifdef CONFIG_CIFS_POSIX
         struct cifsFileInfo *pSMBFile = filep->private_data;
         struct cifs_tcon *tcon;
         __u64   ExtAttrBits = 0;
         __u64   ExtAttrMask = 0;
         __u64   caps;
-#endif /* CONFIG_CIFS_POSIX */
 
         xid = get_xid();
 
@@ -49,12 +47,12 @@ long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
         cifs_sb = CIFS_SB(inode->i_sb);
 
         switch (command) {
-#ifdef CONFIG_CIFS_POSIX
                 case FS_IOC_GETFLAGS:
                         if (pSMBFile == NULL)
                                 break;
                         tcon = tlink_tcon(pSMBFile->tlink);
                         caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
+#ifdef CONFIG_CIFS_POSIX
                         if (CIFS_UNIX_EXTATTR_CAP & caps) {
                                 rc = CIFSGetExtAttr(xid, tcon,
                                                     pSMBFile->fid.netfid,
@@ -63,29 +61,50 @@ long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
                                         rc = put_user(ExtAttrBits &
                                                 FS_FL_USER_VISIBLE,
                                                 (int __user *)arg);
+                                if (rc != EOPNOTSUPP)
+                                        break;
+                        }
+#endif /* CONFIG_CIFS_POSIX */
+                        rc = 0;
+                        if (CIFS_I(inode)->cifsAttrs & ATTR_COMPRESSED) {
+                                /* add in the compressed bit */
+                                ExtAttrBits = FS_COMPR_FL;
+                                rc = put_user(ExtAttrBits & FS_FL_USER_VISIBLE,
+                                              (int __user *)arg);
                         }
                         break;
-
                 case FS_IOC_SETFLAGS:
                         if (pSMBFile == NULL)
                                 break;
                         tcon = tlink_tcon(pSMBFile->tlink);
                         caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
-                        if (CIFS_UNIX_EXTATTR_CAP & caps) {
-                                if (get_user(ExtAttrBits, (int __user *)arg)) {
-                                        rc = -EFAULT;
-                                        break;
-                                }
-                                /*
-                                 * rc = CIFSGetExtAttr(xid, tcon,
-                                 *                     pSMBFile->fid.netfid,
-                                 *                     extAttrBits,
-                                 *                     &ExtAttrMask);
-                                 */
+
+                        if (get_user(ExtAttrBits, (int __user *)arg)) {
+                                rc = -EFAULT;
+                                break;
+                        }
+
+                        /*
+                         * if (CIFS_UNIX_EXTATTR_CAP & caps)
+                         *      rc = CIFSSetExtAttr(xid, tcon,
+                         *                     pSMBFile->fid.netfid,
+                         *                     extAttrBits,
+                         *                     &ExtAttrMask);
+                         * if (rc != EOPNOTSUPP)
+                         *      break;
+                         */
+
+                        /* Currently only flag we can set is compressed flag */
+                        if ((ExtAttrBits & FS_COMPR_FL) == 0)
+                                break;
+
+                        /* Try to set compress flag */
+                        if (tcon->ses->server->ops->set_compression) {
+                                rc = tcon->ses->server->ops->set_compression(
+                                                        xid, tcon, pSMBFile);
+                                cifs_dbg(FYI, "set compress flag rc %d\n", rc);
                         }
-                        cifs_dbg(FYI, "set flags not implemented yet\n");
                         break;
-#endif /* CONFIG_CIFS_POSIX */
                 default:
                         cifs_dbg(FYI, "unsupported ioctl\n");
                         break;