[PATCH 3/8] xfs: handle kmalloc failure when reading attrs

[Dave Chinner <david@xxxxxxxxxxxxx>]

From: Dave Chinner <dchinner@xxxxxxxxxx>

From: Dave Chinner <dchinner@xxxxxxxxxx>

xfsdump uses for 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.

Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
 fs/xfs/xfs_ioctl.c |   11 +++++++----
 1 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 86c86d8..7721962 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -445,9 +445,12 @@ xfs_attrmulti_attr_get(
 
        if (*len > XATTR_SIZE_MAX)
                return EINVAL;
-       kbuf = kmalloc(*len, GFP_KERNEL);
-       if (!kbuf)
-               return ENOMEM;
+       kbuf = kmem_zalloc(*len, KM_SLEEP | KM_MAYFAIL);
+       if (!kbuf) {
+               kbuf = kmem_zalloc_large(*len);
+               if (!kbuf)
+                       return ENOMEM;
+       }
 
        error = xfs_attr_get(XFS_I(inode), name, kbuf, (int *)len, flags);
        if (error)
@@ -457,7 +460,7 @@ xfs_attrmulti_attr_get(
                error = EFAULT;
 
  out_kfree:
-       kfree(kbuf);
+       kmem_free(kbuf);
        return error;
 }
 
-- 
1.7.9