/*
* Attempt to clear the private state associated with a page when an error
* occurs that requires the cached contents of an inode to be written back or
* destroyed
* - Called if either PG_private or fscache is set on the page
* - Caller holds page lock
* - Return 0 if successful, -error otherwise
*/
static int nfs_launder_page(struct page *page)
{
struct inode *inode = page->mapping->host;
struct nfs_inode *nfsi = NFS_I(inode);
dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n",
inode->i_ino, (long long)page_offset(page));
nfs_fscache_wait_on_page_write(nfsi, page);
return nfs_wb_page(inode, page);
}
/*
* Notification that a PTE pointing to an NFS page is about to be made
* writable, implying that someone is about to modify the page through a
* shared-writable mapping
*/
static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct file *filp = vma->vm_file;
struct inode *inode = file_inode(filp);
unsigned pagelen;
int ret = VM_FAULT_NOPAGE;
struct address_space *mapping;
dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%pD2(%lu), offset %lld)\n",
filp, filp->f_mapping->host->i_ino,
(long long)page_offset(page));
/* make sure the cache has finished storing the page */
nfs_fscache_wait_on_page_write(NFS_I(inode), page);
wait_on_bit_action(&NFS_I(inode)->flags, NFS_INO_INVALIDATING,
nfs_wait_bit_killable, TASK_KILLABLE);
lock_page(page);
mapping = page_file_mapping(page);
if (mapping != inode->i_mapping)
goto out_unlock;
wait_on_page_writeback(page);
pagelen = nfs_page_length(page);
if (pagelen == 0)
goto out_unlock;
ret = VM_FAULT_LOCKED;
if (nfs_flush_incompatible(filp, page) == 0 &&
nfs_updatepage(filp, page, 0, pagelen) == 0)
goto out;
ret = VM_FAULT_SIGBUS;
out_unlock:
unlock_page(page);
out:
return ret;
}
/*
* Notification that a PTE pointing to an NFS page is about to be made
* writable, implying that someone is about to modify the page through a
* shared-writable mapping
*/
static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct file *filp = vma->vm_file;
struct dentry *dentry = filp->f_path.dentry;
unsigned pagelen;
int ret = -EINVAL;
struct address_space *mapping;
dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%s/%s(%ld), offset %lld)\n",
dentry->d_parent->d_name.name, dentry->d_name.name,
filp->f_mapping->host->i_ino,
(long long)page_offset(page));
/* make sure the cache has finished storing the page */
nfs_fscache_wait_on_page_write(NFS_I(dentry->d_inode), page);
lock_page(page);
mapping = page->mapping;
if (mapping != dentry->d_inode->i_mapping)
goto out_unlock;
ret = 0;
pagelen = nfs_page_length(page);
if (pagelen == 0)
goto out_unlock;
ret = nfs_flush_incompatible(filp, page);
if (ret != 0)
goto out_unlock;
ret = nfs_updatepage(filp, page, 0, pagelen);
if (ret == 0)
ret = pagelen;
out_unlock:
unlock_page(page);
if (ret)
ret = VM_FAULT_SIGBUS;
return ret;
}
