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[patch 09/12] Hook up compat XFS_IOC_ATTRLIST_BY_HANDLE ioctl handler

To: xfs@xxxxxxxxxxx
Subject: [patch 09/12] Hook up compat XFS_IOC_ATTRLIST_BY_HANDLE ioctl handler
From: sandeen@xxxxxxxxxxx
Date: Tue, 25 Nov 2008 21:20:14 -0600
References: <20081126032005.639750968@xxxxxxxxxxx>
User-agent: quilt/0.46-1
Add a compat handler for XFS_IOC_ATTRLIST_BY_HANDLE

Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxxx>
--

Index: linux-2.6-xfs/fs/xfs/linux-2.6/xfs_ioctl32.h
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/linux-2.6/xfs_ioctl32.h   2008-11-24 
17:00:29.616000880 -0600
+++ linux-2.6-xfs/fs/xfs/linux-2.6/xfs_ioctl32.h        2008-11-24 
17:09:26.128001872 -0600
@@ -123,6 +123,18 @@ typedef struct compat_xfs_swapext {
 
 #define XFS_IOC_SWAPEXT_32     _IOWR('X', 109, struct compat_xfs_swapext)
 
+typedef struct compat_xfs_fsop_attrlist_handlereq {
+       struct compat_xfs_fsop_handlereq hreq; /* handle interface structure */
+       struct xfs_attrlist_cursor      pos; /* opaque cookie, list offset */
+       __u32                           flags;  /* which namespace to use */
+       __u32                           buflen; /* length of buffer supplied */
+       compat_uptr_t                   buffer; /* returned names */
+} __compat_packed compat_xfs_fsop_attrlist_handlereq_t;
+
+/* Note: actually this is read/write */
+#define XFS_IOC_ATTRLIST_BY_HANDLE_32 \
+       _IOW('X', 122, struct compat_xfs_fsop_attrlist_handlereq)
+
 #ifdef BROKEN_X86_ALIGNMENT
 /* on ia32 l_start is on a 32-bit boundary */
 typedef struct compat_xfs_flock64 {
Index: linux-2.6-xfs/fs/xfs/linux-2.6/xfs_ioctl32.c
===================================================================
--- linux-2.6-xfs.orig/fs/xfs/linux-2.6/xfs_ioctl32.c   2008-11-24 
17:00:30.969063389 -0600
+++ linux-2.6-xfs/fs/xfs/linux-2.6/xfs_ioctl32.c        2008-11-24 
17:09:26.127001434 -0600
@@ -47,6 +47,7 @@
 #include "xfs_fsops.h"
 #include "xfs_alloc.h"
 #include "xfs_rtalloc.h"
+#include "xfs_attr.h"
 #include "xfs_ioctl.h"
 #include "xfs_ioctl32.h"
 
@@ -344,6 +345,138 @@ xfs_compat_handlereq_copyin(
        return 0;
 }
 
+/*
+ * Convert userspace handle data into inode.
+ *
+ * We use the fact that all the fsop_handlereq ioctl calls have a data
+ * structure argument whose first component is always a xfs_fsop_handlereq_t,
+ * so we can pass that sub structure into this handy, shared routine.
+ *
+ * If no error, caller must always iput the returned inode.
+ */
+STATIC int
+xfs_vget_fsop_handlereq_compat(
+       xfs_mount_t             *mp,
+       struct inode            *parinode,      /* parent inode pointer    */
+       compat_xfs_fsop_handlereq_t     *hreq,
+       struct inode            **inode)
+{
+       void                    __user *hanp;
+       size_t                  hlen;
+       xfs_fid_t               *xfid;
+       xfs_handle_t            *handlep;
+       xfs_handle_t            handle;
+       xfs_inode_t             *ip;
+       xfs_ino_t               ino;
+       __u32                   igen;
+       int                     error;
+
+       /*
+        * Only allow handle opens under a directory.
+        */
+       if (!S_ISDIR(parinode->i_mode))
+               return XFS_ERROR(ENOTDIR);
+
+       hanp = compat_ptr(hreq->ihandle);
+       hlen = hreq->ihandlen;
+       handlep = &handle;
+
+       if (hlen < sizeof(handlep->ha_fsid) || hlen > sizeof(*handlep))
+               return XFS_ERROR(EINVAL);
+       if (copy_from_user(handlep, hanp, hlen))
+               return XFS_ERROR(EFAULT);
+       if (hlen < sizeof(*handlep))
+               memset(((char *)handlep) + hlen, 0, sizeof(*handlep) - hlen);
+       if (hlen > sizeof(handlep->ha_fsid)) {
+               if (handlep->ha_fid.fid_len !=
+                   (hlen - sizeof(handlep->ha_fsid) -
+                           sizeof(handlep->ha_fid.fid_len)) ||
+                   handlep->ha_fid.fid_pad)
+                       return XFS_ERROR(EINVAL);
+       }
+
+       /*
+        * Crack the handle, obtain the inode # & generation #
+        */
+       xfid = (struct xfs_fid *)&handlep->ha_fid;
+       if (xfid->fid_len == sizeof(*xfid) - sizeof(xfid->fid_len)) {
+               ino  = xfid->fid_ino;
+               igen = xfid->fid_gen;
+       } else {
+               return XFS_ERROR(EINVAL);
+       }
+
+       /*
+        * Get the XFS inode, building a Linux inode to go with it.
+        */
+       error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_SHARED, &ip, 0);
+       if (error)
+               return error;
+       if (ip == NULL)
+               return XFS_ERROR(EIO);
+       if (ip->i_d.di_gen != igen) {
+               xfs_iput_new(ip, XFS_ILOCK_SHARED);
+               return XFS_ERROR(ENOENT);
+       }
+
+       xfs_iunlock(ip, XFS_ILOCK_SHARED);
+
+       *inode = VFS_I(ip);
+       return 0;
+}
+
+STATIC int
+xfs_compat_attrlist_by_handle(
+       xfs_mount_t             *mp,
+       void                    __user *arg,
+       struct inode            *parinode)
+{
+       int                     error;
+       attrlist_cursor_kern_t  *cursor;
+       compat_xfs_fsop_attrlist_handlereq_t al_hreq;
+       struct inode            *inode;
+       char                    *kbuf;
+
+       if (!capable(CAP_SYS_ADMIN))
+               return -XFS_ERROR(EPERM);
+       if (copy_from_user(&al_hreq, arg,
+                          sizeof(compat_xfs_fsop_attrlist_handlereq_t)))
+               return -XFS_ERROR(EFAULT);
+       if (al_hreq.buflen > XATTR_LIST_MAX)
+               return -XFS_ERROR(EINVAL);
+
+       /*
+        * Reject flags, only allow namespaces.
+        */
+       if (al_hreq.flags & ~(ATTR_ROOT | ATTR_SECURE))
+               return -XFS_ERROR(EINVAL);
+
+       error = xfs_vget_fsop_handlereq_compat(mp, parinode, &al_hreq.hreq,
+                                              &inode);
+       if (error)
+               goto out;
+
+       kbuf = kmalloc(al_hreq.buflen, GFP_KERNEL);
+       if (!kbuf)
+               goto out_vn_rele;
+
+       cursor = (attrlist_cursor_kern_t *)&al_hreq.pos;
+       error = xfs_attr_list(XFS_I(inode), kbuf, al_hreq.buflen,
+                                       al_hreq.flags, cursor);
+       if (error)
+               goto out_kfree;
+
+       if (copy_to_user(compat_ptr(al_hreq.buffer), kbuf, al_hreq.buflen))
+               error = -EFAULT;
+
+ out_kfree:
+       kfree(kbuf);
+ out_vn_rele:
+       iput(inode);
+ out:
+       return -error;
+}
+
 STATIC long
 xfs_compat_ioctl(
        xfs_inode_t     *ip,
@@ -369,7 +502,6 @@ xfs_compat_ioctl(
        case XFS_IOC_GETBMAPX:
 /* not handled
        case XFS_IOC_FSSETDM_BY_HANDLE:
-       case XFS_IOC_ATTRLIST_BY_HANDLE:
        case XFS_IOC_ATTRMULTI_BY_HANDLE:
 */
        case XFS_IOC_FSCOUNTS:
@@ -477,6 +609,8 @@ xfs_compat_ioctl(
                        return -XFS_ERROR(EFAULT);
                return xfs_readlink_by_handle(mp, &hreq, inode);
        }
+       case XFS_IOC_ATTRLIST_BY_HANDLE_32:
+               return xfs_compat_attrlist_by_handle(mp, arg, inode);
        default:
                return -XFS_ERROR(ENOIOCTLCMD);
        }

-- 

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