[XFS] avoid xfs_getattr in XFS_IOC_FSGETXATTR ioctl

No need to call into xfs_getattr and put a big bhv_vattr_t on the stack
just to get a little information from the XFS inode.

Add a helper called xfs_ioc_fsgetxattr instead that deals with retrieving
the information in a clean way.

SGI-PV: 968563
SGI-Modid: xfs-linux-melb:xfs-kern:29780a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>

diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index c9b0c9e..ffec630 100644 (file)
--- a/fs/xfs/linux-2.6/xfs_ioctl.c
+++ b/fs/xfs/linux-2.6/xfs_ioctl.c
@@ -709,6 +709,12 @@ xfs_ioc_xattr(
        void                    __user *arg);
 
 STATIC int
+xfs_ioc_fsgetxattr(
+       xfs_inode_t             *ip,
+       int                     attr,
+       void                    __user *arg);
+
+STATIC int
 xfs_ioc_getbmap(
        struct xfs_inode        *ip,
        int                     flags,
@@ -783,11 +789,13 @@ xfs_ioctl(
        case XFS_IOC_GETVERSION:
                return put_user(inode->i_generation, (int __user *)arg);
 
+       case XFS_IOC_FSGETXATTR:
+               return xfs_ioc_fsgetxattr(ip, 0, arg);
+       case XFS_IOC_FSGETXATTRA:
+               return xfs_ioc_fsgetxattr(ip, 1, arg);
        case XFS_IOC_GETXFLAGS:
        case XFS_IOC_SETXFLAGS:
-       case XFS_IOC_FSGETXATTR:
        case XFS_IOC_FSSETXATTR:
-       case XFS_IOC_FSGETXATTRA:
                return xfs_ioc_xattr(vp, ip, filp, cmd, arg);
 
        case XFS_IOC_FSSETDM: {
@@ -1162,6 +1170,42 @@ xfs_di2lxflags(
 }
 
 STATIC int
+xfs_ioc_fsgetxattr(
+       xfs_inode_t             *ip,
+       int                     attr,
+       void                    __user *arg)
+{
+       struct fsxattr          fa;
+
+       xfs_ilock(ip, XFS_ILOCK_SHARED);
+       fa.fsx_xflags = xfs_ip2xflags(ip);
+       fa.fsx_extsize = ip->i_d.di_extsize << ip->i_mount->m_sb.sb_blocklog;
+       fa.fsx_projid = ip->i_d.di_projid;
+
+       if (attr) {
+               if (ip->i_afp) {
+                       if (ip->i_afp->if_flags & XFS_IFEXTENTS)
+                               fa.fsx_nextents = ip->i_afp->if_bytes /
+                                                       sizeof(xfs_bmbt_rec_t);
+                       else
+                               fa.fsx_nextents = ip->i_d.di_anextents;
+               } else
+                       fa.fsx_nextents = 0;
+       } else {
+               if (ip->i_df.if_flags & XFS_IFEXTENTS)
+                       fa.fsx_nextents = ip->i_df.if_bytes /
+                                               sizeof(xfs_bmbt_rec_t);
+               else
+                       fa.fsx_nextents = ip->i_d.di_nextents;
+       }
+       xfs_iunlock(ip, XFS_ILOCK_SHARED);
+
+       if (copy_to_user(arg, &fa, sizeof(fa)))
+               return -EFAULT;
+       return 0;
+}
+
+STATIC int
 xfs_ioc_xattr(
        bhv_vnode_t             *vp,
        xfs_inode_t             *ip,
@@ -1180,27 +1224,6 @@ xfs_ioc_xattr(
                return -ENOMEM;
 
        switch (cmd) {
-       case XFS_IOC_FSGETXATTR: {
-               vattr->va_mask = XFS_AT_XFLAGS | XFS_AT_EXTSIZE | \
-                                XFS_AT_NEXTENTS | XFS_AT_PROJID;
-               error = xfs_getattr(ip, vattr, 0);
-               if (unlikely(error)) {
-                       error = -error;
-                       break;
-               }
-
-               fa.fsx_xflags   = vattr->va_xflags;
-               fa.fsx_extsize  = vattr->va_extsize;
-               fa.fsx_nextents = vattr->va_nextents;
-               fa.fsx_projid   = vattr->va_projid;
-
-               if (copy_to_user(arg, &fa, sizeof(fa))) {
-                       error = -EFAULT;
-                       break;
-               }
-               break;
-       }
-
        case XFS_IOC_FSSETXATTR: {
                if (copy_from_user(&fa, arg, sizeof(fa))) {
                        error = -EFAULT;
@@ -1223,27 +1246,6 @@ xfs_ioc_xattr(
                break;
        }
 
-       case XFS_IOC_FSGETXATTRA: {
-               vattr->va_mask = XFS_AT_XFLAGS | XFS_AT_EXTSIZE | \
-                                XFS_AT_ANEXTENTS | XFS_AT_PROJID;
-               error = xfs_getattr(ip, vattr, 0);
-               if (unlikely(error)) {
-                       error = -error;
-                       break;
-               }
-
-               fa.fsx_xflags   = vattr->va_xflags;
-               fa.fsx_extsize  = vattr->va_extsize;
-               fa.fsx_nextents = vattr->va_anextents;
-               fa.fsx_projid   = vattr->va_projid;
-
-               if (copy_to_user(arg, &fa, sizeof(fa))) {
-                       error = -EFAULT;
-                       break;
-               }
-               break;
-       }
-
        case XFS_IOC_GETXFLAGS: {
                flags = xfs_di2lxflags(ip->i_d.di_flags);
                if (copy_to_user(arg, &flags, sizeof(flags)))