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authorAl Viro <viro@zeniv.linux.org.uk>2015-11-17 09:07:57 +0300
committerAl Viro <viro@zeniv.linux.org.uk>2015-12-09 06:41:36 +0300
commit21fc61c73c3903c4c312d0802da01ec2b323d174 (patch)
treea26c29e3fbb766f00b023724e9e5b8b9bba9b879 /fs/befs/linuxvfs.c
parentaa80deab33a8fb180e718f5e45514db19aade165 (diff)
downloadlinux-21fc61c73c3903c4c312d0802da01ec2b323d174.tar.xz
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>
Diffstat (limited to 'fs/befs/linuxvfs.c')
-rw-r--r--fs/befs/linuxvfs.c5
1 files changed, 2 insertions, 3 deletions
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;
}