[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>

1 files changed, 46 insertions, 44 deletions

diff --git a/fs/xfs/linux-2.6/xfs_ioctl.c b/fs/xfs/linux-2.6/xfs_ioctl.c
index c9b0c9e6813..ffec630e7db 100644
--- 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)))