From 61f68816211ee4b884dc0dda8dd4d977548f4865 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Thu, 28 Nov 2013 14:28:14 +0800 Subject: [PATCH] ceph: check caps in filemap_fault and page_mkwrite 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 Reviewed-by: Sage Weil --- 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 c346b8479f99..ebda329611be 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -1210,6 +1210,41 @@ 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. @@ -1217,23 +1252,41 @@ 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; + loff_t size = i_size_read(inode); + size_t len; + int want, got, ret; - /* Update time before taking page lock */ - file_update_time(vma->vm_file); - - 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("page_mkwrite %p %llu~%zd got cap refs on %s\n", + inode, off, len, ceph_cap_string(got)); + + /* Update time before taking page lock */ + file_update_time(vma->vm_file); lock_page(page); @@ -1255,14 +1308,26 @@ 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, };