xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

don't put symlink bodies in pagecache into highmem

Browse Source 
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>
This commit is contained in:
Al Viro
2015-11-17 01:07:57 -05:00
parent aa80deab33
commit 21fc61c73c
57 changed files with 81 additions and 46 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
fs/efs/inode.c
View File

@@ -151,6 +151,7 @@ struct inode *efs_iget(struct super_block *super, unsigned long ino)
break;
case S_IFLNK:
inode->i_op = &page_symlink_inode_operations;
inode_nohighmem(inode);
inode->i_data.a_ops = &efs_symlink_aops;
break;
case S_IFCHR:

4
fs/efs/symlink.c
View File

@@ -13,7 +13,7 @@
static int efs_symlink_readpage(struct file *file, struct page *page)
{
char *link = kmap(page);
char *link = page_address(page);
struct buffer_head * bh;
struct inode * inode = page->mapping->host;
efs_block_t size = inode->i_size;
@@ -39,12 +39,10 @@ static int efs_symlink_readpage(struct file *file, struct page *page)
}
link[size] = '\0';
SetPageUptodate(page);
kunmap(page);
unlock_page(page);
return 0;
fail:
SetPageError(page);
kunmap(page);
unlock_page(page);
return err;
}