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>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c
index 6dd107d7421e..19b33f8151f1 100644
--- a/fs/hfsplus/inode.c
+++ b/fs/hfsplus/inode.c
@@ -403,6 +403,7 @@ struct inode *hfsplus_new_inode(struct super_block *sb, umode_t mode)
         } else if (S_ISLNK(inode->i_mode)) {
                 sbi->file_count++;
                 inode->i_op = &page_symlink_inode_operations;
+                inode_nohighmem(inode);
                 inode->i_mapping->a_ops = &hfsplus_aops;
                 hip->clump_blocks = 1;
         } else
@@ -526,6 +527,7 @@ int hfsplus_cat_read_inode(struct inode *inode, struct hfs_find_data *fd)
                         inode->i_mapping->a_ops = &hfsplus_aops;
                 } else if (S_ISLNK(inode->i_mode)) {
                         inode->i_op = &page_symlink_inode_operations;
+                        inode_nohighmem(inode);
                         inode->i_mapping->a_ops = &hfsplus_aops;
                 } else {
                         init_special_inode(inode, inode->i_mode,