[PATCH] xfs: xfs: fallback to vmalloc for large buffers in xfs_compat_attrlist_by_handle

Eric Sandeen
2013-04-25T16:13:11Z

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>
---

diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c
index 63b8fc4..c0c6625 100644
--- 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;