don't put symlink bodies in pagecache into highmem
kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.
new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases. page_follow_link_light()
instrumented to yell about anything missed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index a969ab3..f27e0c2 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3132,6 +3132,7 @@
if ((disk_link.len > EXT4_N_BLOCKS * 4)) {
if (!encryption_required)
inode->i_op = &ext4_symlink_inode_operations;
+ inode_nohighmem(inode);
ext4_set_aops(inode);
/*
* We cannot call page_symlink() with transaction started
