On Tue, 17 Dec 2013, Yan, Zheng wrote:
> From: "Yan, Zheng" <zheng.z.yan@xxxxxxxxx>
>
> Adds cap check to the page fault handler. The check prevents page
> fault handler from adding new page to the page cache while Fcb caps
> are being revoked. This solves Fc revoking hang in multiple clients
> mmap IO workload.
>
> Signed-off-by: Yan, Zheng <zheng.z.yan@xxxxxxxxx>
Aside from the typo below, this looks good to me.
Reviewed-by: Sage Weil <sage@xxxxxxxxxxx>
> ---
> fs/ceph/addr.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++--------
> 1 file changed, 77 insertions(+), 12 deletions(-)
>
> diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
> index ec3ba43..4212694 100644
> --- a/fs/ceph/addr.c
> +++ b/fs/ceph/addr.c
> @@ -1207,6 +1207,41 @@ const struct address_space_operations ceph_aops = {
> /*
> * vm ops
> */
> +static int ceph_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
> +{
> + struct inode *inode = file_inode(vma->vm_file);
> + struct ceph_inode_info *ci = ceph_inode(inode);
> + struct ceph_file_info *fi = vma->vm_file->private_data;
> + loff_t off = vmf->pgoff << PAGE_CACHE_SHIFT;
> + int want, got, ret;
> +
> + dout("filemap_fault %p %llx.%llx %llu~%zd trying to get caps\n",
> + inode, ceph_vinop(inode), off, PAGE_CACHE_SIZE);
> + if (fi->fmode & CEPH_FILE_MODE_LAZY)
> + want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
> + else
> + want = CEPH_CAP_FILE_CACHE;
> + while (1) {
> + got = 0;
> + ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want, &got, -1);
> + if (ret == 0)
> + break;
> + if (ret != -ERESTARTSYS) {
> + WARN_ON(1);
> + return VM_FAULT_SIGBUS;
> + }
> + }
> + dout("filemap_fault %p %llu~%zd got cap refs on %s\n",
> + inode, off, PAGE_CACHE_SIZE, ceph_cap_string(got));
> +
> + ret = filemap_fault(vma, vmf);
> +
> + dout("filemap_fault %p %llu~%zd dropping cap refs on %s ret %d\n",
> + inode, off, PAGE_CACHE_SIZE, ceph_cap_string(got), ret);
> + ceph_put_cap_refs(ci, got);
> +
> + return ret;
> +}
>
> /*
> * Reuse write_begin here for simplicity.
> @@ -1214,23 +1249,41 @@ const struct address_space_operations ceph_aops = {
> static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
> {
> struct inode *inode = file_inode(vma->vm_file);
> - struct page *page = vmf->page;
> + struct ceph_inode_info *ci = ceph_inode(inode);
> + struct ceph_file_info *fi = vma->vm_file->private_data;
> struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
> + struct page *page = vmf->page;
> loff_t off = page_offset(page);
> - loff_t size, len;
> - int ret;
> -
> - /* Update time before taking page lock */
> - file_update_time(vma->vm_file);
> + loff_t size = i_size_read(inode);
> + size_t len;
> + int want, got, ret;
>
> - size = i_size_read(inode);
> if (off + PAGE_CACHE_SIZE <= size)
> len = PAGE_CACHE_SIZE;
> else
> len = size & ~PAGE_CACHE_MASK;
>
> - dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode,
> - off, len, page, page->index);
> + dout("page_mkwrite %p %llx.%llx %llu~%zd getting caps i_size %llu\n",
> + inode, ceph_vinop(inode), off, len, size);
> + if (fi->fmode & CEPH_FILE_MODE_LAZY)
> + want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
> + else
> + want = CEPH_CAP_FILE_BUFFER;
> + while (1) {
> + got = 0;
> + ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, &got, off + len);
> + if (ret == 0)
> + break;
> + if (ret != -ERESTARTSYS) {
> + WARN_ON(1);
> + return VM_FAULT_SIGBUS;
> + }
> + }
> + dout("papge_mkwrite %p %llu~%zd got cap refs on %s\n",
page_mkwrite
> + inode, off, len, ceph_cap_string(got));
> +
> + /* Update time before taking page lock */
> + file_update_time(vma->vm_file);
>
> lock_page(page);
>
> @@ -1252,14 +1305,26 @@ static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
> ret = VM_FAULT_SIGBUS;
> }
> out:
> - dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret);
> - if (ret != VM_FAULT_LOCKED)
> + if (ret != VM_FAULT_LOCKED) {
> unlock_page(page);
> + } else {
> + int dirty;
> + spin_lock(&ci->i_ceph_lock);
> + dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR);
> + spin_unlock(&ci->i_ceph_lock);
> + if (dirty)
> + __mark_inode_dirty(inode, dirty);
> + }
> +
> + dout("page_mkwrite %p %llu~%zd dropping cap refs on %s ret %d\n",
> + inode, off, len, ceph_cap_string(got), ret);
> + ceph_put_cap_refs(ci, got);
> +
> return ret;
> }
>
> static struct vm_operations_struct ceph_vmops = {
> - .fault = filemap_fault,
> + .fault = ceph_filemap_fault,
> .page_mkwrite = ceph_page_mkwrite,
> .remap_pages = generic_file_remap_pages,
> };
> --
> 1.8.1.4
>
>
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