Commit fdc85222 authored Mar 12, 2020 by Daniel Xu Committed by Tejun Heo Mar 16, 2020

kernfs: kvmalloc xattr value instead of kmalloc



xattr values have a 64k maximum size. This can result in an order 4
kmalloc request which can be difficult to fulfill. Since xattrs do not
need physically contiguous memory, we can switch to kvmalloc and not
have to worry about higher order allocations failing.

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Acked-by: Chris Down <chris@chrisdown.name>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

parent e7b20d97

fs/xattr.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -817,7 +817,7 @@ struct simple_xattr simple_xattr_alloc(const void value, size_t size)
		if (len < sizeof(*new_xattr))
		return NULL;

		new_xattr = kmalloc(len, GFP_KERNEL);
		new_xattr = kvmalloc(len, GFP_KERNEL);
		if (!new_xattr)
		return NULL;

		@@ -882,7 +882,7 @@ int simple_xattr_set(struct simple_xattrs xattrs, const char name,

		new_xattr->name = kstrdup(name, GFP_KERNEL);
		if (!new_xattr->name) {
		kfree(new_xattr);
		kvfree(new_xattr);
		return -ENOMEM;
		}
		}
		@@ -912,7 +912,7 @@ out:
		spin_unlock(&xattrs->lock);
		if (xattr) {
		kfree(xattr->name);
		kfree(xattr);
		kvfree(xattr);
		}
		return err;

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