[CIFS] Allow to set extended attribute cifs_acl (try #2)

Allow setting cifs_acl on the server.
Pass on to the server the ACL blob generated by an application.
cifs is just a pass-through, it does not monitor or inspect the contents
of the blob, server decides whether to enforce/apply the ACL blob composed
by an application.
If setting of ACL is succeessful, mark the inode for revalidation.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

3 files changed, 23 insertions, 1 deletions

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index beeebf194234..a0d11eab14e5 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -688,7 +688,7 @@ out:
 }
 
 /* Set an ACL on the server */
-static int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
+int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
                                 struct inode *inode, const char *path)
 {
         struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index e94526949677..0e4e057e2891 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -143,6 +143,8 @@ extern int cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb,
 extern int mode_to_cifs_acl(struct inode *inode, const char *path, __u64);
 extern struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *, struct inode *,
                                         const char *, u32 *);
+extern int set_cifs_acl(struct cifs_ntsd *, __u32, struct inode *,
+                                const char *);
 
 extern int cifs_mount(struct super_block *, struct cifs_sb_info *, char *,
                         const char *);
diff --git a/fs/cifs/xattr.c b/fs/cifs/xattr.c
index eae2a1491608..912995e013ec 100644
--- a/fs/cifs/xattr.c
+++ b/fs/cifs/xattr.c
@@ -112,6 +112,7 @@ int cifs_setxattr(struct dentry *direntry, const char *ea_name,
         struct cifsTconInfo *pTcon;
         struct super_block *sb;
         char *full_path;
+        struct cifs_ntsd *pacl;
 
         if (direntry == NULL)
                 return -EIO;
@@ -166,6 +167,25 @@ int cifs_setxattr(struct dentry *direntry, const char *ea_name,
                 rc = CIFSSMBSetEA(xid, pTcon, full_path, ea_name, ea_value,
                         (__u16)value_size, cifs_sb->local_nls,
                         cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
+        } else if (strncmp(ea_name, CIFS_XATTR_CIFS_ACL,
+                        strlen(CIFS_XATTR_CIFS_ACL)) == 0) {
+                pacl = kmalloc(value_size, GFP_KERNEL);
+                if (!pacl) {
+                        cFYI(1, "%s: Can't allocate memory for ACL",
+                                        __func__);
+                        rc = -ENOMEM;
+                } else {
+#ifdef CONFIG_CIFS_ACL
+                        memcpy(pacl, ea_value, value_size);
+                        rc = set_cifs_acl(pacl, value_size,
+                                direntry->d_inode, full_path);
+                        if (rc == 0) /* force revalidate of the inode */
+                                CIFS_I(direntry->d_inode)->time = 0;
+                        kfree(pacl);
+#else
+                        cFYI(1, "Set CIFS ACL not supported yet");
+#endif /* CONFIG_CIFS_ACL */
+                }
         } else {
                 int temp;
                 temp = strncmp(ea_name, POSIX_ACL_XATTR_ACCESS,