From 21fc61c73c3903c4c312d0802da01ec2b323d174 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 17 Nov 2015 01:07:57 -0500 Subject: 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 --- fs/befs/linuxvfs.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'fs/befs') diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c index 1c8b0dca8b50..25250fa87086 100644 --- a/fs/befs/linuxvfs.c +++ b/fs/befs/linuxvfs.c @@ -397,6 +397,7 @@ static struct inode *befs_iget(struct super_block *sb, unsigned long ino) } else if (S_ISLNK(inode->i_mode)) { if (befs_ino->i_flags & BEFS_LONG_SYMLINK) { inode->i_op = &page_symlink_inode_operations; + inode_nohighmem(inode); inode->i_mapping->a_ops = &befs_symlink_aops; } else { inode->i_link = befs_ino->i_data.symlink; @@ -469,7 +470,7 @@ static int befs_symlink_readpage(struct file *unused, struct page *page) struct befs_inode_info *befs_ino = BEFS_I(inode); befs_data_stream *data = &befs_ino->i_data.ds; befs_off_t len = data->size; - char *link = kmap(page); + char *link = page_address(page); if (len == 0 || len > PAGE_SIZE) { befs_error(sb, "Long symlink with illegal length"); @@ -483,12 +484,10 @@ static int befs_symlink_readpage(struct file *unused, struct page *page) } link[len - 1] = '\0'; SetPageUptodate(page); - kunmap(page); unlock_page(page); return 0; fail: SetPageError(page); - kunmap(page); unlock_page(page); return -EIO; } -- cgit v1.2.3-59-g8ed1b