xfs: fallback to vmalloc for large buffers in xfs_compat_attrlist_by_handle

Shamelessly copied from dchinner's:
ad650f5b xfs: fallback to vmalloc for large buffers in xfs_attrmulti_attr_get

xfsdump uses a large buffer for extended attributes, which has a
kmalloc'd shadow buffer in the kernel. This can fail after the
system has been running for some time as it is a high order
allocation. Add a fallback to vmalloc so that it doesn't require
contiguous memory and so won't randomly fail while xfsdump is
running.

This was done for xfs_attrlist_by_handle but
xfs_compat_attrlist_by_handle (the 32-bit version) needs the same
attention.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c
index 63b8fc4..c0c6625 100644 (file)
--- a/fs/xfs/xfs_ioctl32.c
+++ b/fs/xfs/xfs_ioctl32.c
@@ -373,9 +373,12 @@ xfs_compat_attrlist_by_handle(
                return PTR_ERR(dentry);
 
        error = -ENOMEM;
-       kbuf = kmalloc(al_hreq.buflen, GFP_KERNEL);
-       if (!kbuf)
-               goto out_dput;
+       kbuf = kmem_zalloc(al_hreq.buflen, KM_SLEEP | KM_MAYFAIL);
+       if (!kbuf) {
+               kbuf = kmem_zalloc_large(al_hreq.buflen);
+               if (!kbuf)
+                       goto out_dput;
+       }
 
        cursor = (attrlist_cursor_kern_t *)&al_hreq.pos;
        error = -xfs_attr_list(XFS_I(dentry->d_inode), kbuf, al_hreq.buflen,
@@ -387,7 +390,10 @@ xfs_compat_attrlist_by_handle(
                error = -EFAULT;
 
  out_kfree:
-       kfree(kbuf);
+       if (is_vmalloc_addr(kbuf))
+               kmem_free_large(kbuf);
+       else
+               kmem_free(kbuf);
  out_dput:
        dput(dentry);
        return error;