+ struct ll_async_page *llap;
+ ENTRY;
+
+ llap = llap_from_page(page, LLAP_ORIGIN_UNKNOWN);
+ if (IS_ERR(llap))
+ RETURN(PTR_ERR(llap));
+
+ llap_write_pending(page->mapping->host, llap);
+ RETURN(__set_page_dirty_nobuffers(page));
+}
+
+#define MAX_DIRECTIO_SIZE 2*1024*1024*1024UL
+
+static inline int ll_get_user_pages(int rw, unsigned long user_addr,
+ size_t size, struct page ***pages)
+{
+ int result = -ENOMEM;
+ int page_count;
+
+ /* set an arbitrary limit to prevent arithmetic overflow */
+ if (size > MAX_DIRECTIO_SIZE) {
+ *pages = NULL;
+ return -EFBIG;
+ }
+
+ page_count = (user_addr + size + CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT;
+ page_count -= user_addr >> CFS_PAGE_SHIFT;
+
+ OBD_ALLOC_WAIT(*pages, page_count * sizeof(**pages));
+ if (*pages) {
+ down_read(¤t->mm->mmap_sem);
+ result = get_user_pages(current, current->mm, user_addr,
+ page_count, (rw == READ), 0, *pages,
+ NULL);
+ up_read(¤t->mm->mmap_sem);
+ if (result < 0)
+ OBD_FREE(*pages, page_count * sizeof(**pages));
+ }
+
+ return result;
+}
+
+/* ll_free_user_pages - tear down page struct array
+ * @pages: array of page struct pointers underlying target buffer */
+static void ll_free_user_pages(struct page **pages, int npages, int do_dirty)
+{
+ int i;
+
+ for (i = 0; i < npages; i++) {
+ if (do_dirty)
+ set_page_dirty_lock(pages[i]);
+ page_cache_release(pages[i]);
+ }
+
+ OBD_FREE(pages, npages * sizeof(*pages));
+}
+
+static ssize_t ll_direct_IO_26_seg(int rw, struct inode *inode,
+ struct address_space *mapping,
+ struct obd_info *oinfo,
+ struct ptlrpc_request_set *set,
+ size_t size, loff_t file_offset,
+ struct page **pages, int page_count)
+{
+ struct brw_page *pga;
+ int i, rc = 0;
+ size_t length;
+ ENTRY;
+
+ OBD_ALLOC(pga, sizeof(*pga) * page_count);
+ if (!pga) {
+ CDEBUG(D_VFSTRACE, "sizeof(*pga) = %u page_count = %u\n",
+ (int)sizeof(*pga), page_count);
+ RETURN(-ENOMEM);
+ }
+
+ for (i = 0, length = size; length > 0;
+ length -=pga[i].count, file_offset +=pga[i].count,i++) {/*i last!*/
+ pga[i].pg = pages[i];
+ pga[i].off = file_offset;
+ /* To the end of the page, or the length, whatever is less */
+ pga[i].count = min_t(int, CFS_PAGE_SIZE -
+ (file_offset & ~CFS_PAGE_MASK),
+ length);
+ pga[i].flag = 0;
+ if (rw == READ)
+ POISON_PAGE(pages[i], 0x0d);
+ }
+
+ rc = obd_brw_async(rw == WRITE ? OBD_BRW_WRITE : OBD_BRW_READ,
+ ll_i2dtexp(inode), oinfo, page_count,
+ pga, NULL, set);
+ if (rc == 0)
+ rc = size;
+
+ OBD_FREE(pga, sizeof(*pga) * page_count);
+ RETURN(rc);
+}
+
+/* This is the maximum size of a single O_DIRECT request, based on a 128kB
+ * kmalloc limit. We need to fit all of the brw_page structs, each one
+ * representing PAGE_SIZE worth of user data, into a single buffer, and
+ * then truncate this to be a full-sized RPC. This is 22MB for 4kB pages. */
+#define MAX_DIO_SIZE ((128 * 1024 / sizeof(struct brw_page) * CFS_PAGE_SIZE) & \
+ ~(PTLRPC_MAX_BRW_SIZE - 1))
+static ssize_t ll_direct_IO_26(int rw, struct kiocb *iocb,
+ const struct iovec *iov, loff_t file_offset,
+ unsigned long nr_segs)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ ssize_t count = iov_length(iov, nr_segs), tot_bytes = 0;
+ struct ll_inode_info *lli = ll_i2info(inode);
+ struct lov_stripe_md *lsm = lli->lli_smd;
+ struct ptlrpc_request_set *set;
+ struct obd_info oinfo;
+ struct obdo oa;
+ unsigned long seg = 0;
+ size_t size = MAX_DIO_SIZE;
+ int opc;
+ ENTRY;
+
+ if (!lli->lli_smd || !lli->lli_smd->lsm_object_id)
+ RETURN(-EBADF);
+
+ /* FIXME: io smaller than PAGE_SIZE is broken on ia64 ??? */
+ if ((file_offset & ~CFS_PAGE_MASK) || (count & ~CFS_PAGE_MASK))
+ RETURN(-EINVAL);
+
+ CDEBUG(D_VFSTRACE, "VFS Op:inode=%lu/%u(%p), size="LPSZ" (max %lu), "
+ "offset=%lld=%llx, pages "LPSZ" (max %lu)\n",
+ inode->i_ino, inode->i_generation, inode, count, MAX_DIO_SIZE,
+ file_offset, file_offset, count >> CFS_PAGE_SHIFT,
+ MAX_DIO_SIZE >> CFS_PAGE_SHIFT);
+
+ if (rw == WRITE) {
+ ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_DIRECT_WRITE, count);
+ opc = CAPA_OPC_OSS_WRITE;
+ llap_write_pending(inode, NULL);
+ } else {
+ ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_DIRECT_READ, count);
+ opc = CAPA_OPC_OSS_RW;
+ }
+
+ /* Check that all user buffers are aligned as well */
+ for (seg = 0; seg < nr_segs; seg++) {
+ if (((unsigned long)iov[seg].iov_base & ~CFS_PAGE_MASK) ||
+ (iov[seg].iov_len & ~CFS_PAGE_MASK))
+ RETURN(-EINVAL);
+ }
+
+ set = ptlrpc_prep_set();
+ if (set == NULL)
+ RETURN(-ENOMEM);
+
+ ll_inode_fill_obdo(inode, rw, &oa);
+ oinfo.oi_oa = &oa;
+ oinfo.oi_md = lsm;
+ oinfo.oi_capa = ll_osscapa_get(inode, opc);
+
+ /* need locking between buffered and direct access. and race with
+ *size changing by concurrent truncates and writes. */
+ if (rw == READ)
+ LOCK_INODE_MUTEX(inode);
+
+ for (seg = 0; seg < nr_segs; seg++) {
+ size_t iov_left = iov[seg].iov_len;
+ unsigned long user_addr = (unsigned long)iov[seg].iov_base;
+
+ if (rw == READ) {
+ if (file_offset >= inode->i_size)
+ break;
+ if (file_offset + iov_left > inode->i_size)
+ iov_left = inode->i_size - file_offset;
+ }
+
+ while (iov_left > 0) {
+ struct page **pages;
+ int page_count;
+ ssize_t result;
+
+ page_count = ll_get_user_pages(rw, user_addr,
+ min(size, iov_left),
+ &pages);
+ LASSERT(page_count != 0);
+ if (page_count > 0) {
+ result = ll_direct_IO_26_seg(rw, inode,
+ file->f_mapping,
+ &oinfo, set,
+ min(size,iov_left),
+ file_offset, pages,
+ page_count);
+ ll_free_user_pages(pages, page_count, rw==READ);
+ } else {
+ result = 0;
+ }
+ if (page_count < 0 || result <= 0) {
+ /* If we can't allocate a large enough buffer
+ * for the request, shrink it to a smaller
+ * PAGE_SIZE multiple and try again.
+ * We should always be able to kmalloc for a
+ * page worth of page pointers = 4MB on i386. */
+ if ((page_count == -ENOMEM||result == -ENOMEM)&&
+ size > (CFS_PAGE_SIZE / sizeof(*pages)) *
+ CFS_PAGE_SIZE) {
+ size = ((((size / 2) - 1) |
+ ~CFS_PAGE_MASK) + 1) &
+ CFS_PAGE_MASK;
+ CDEBUG(D_VFSTRACE, "DIO size now %u\n",
+ (int)size);
+ continue;
+ }
+
+ if (tot_bytes <= 0)
+ tot_bytes = page_count < 0 ? page_count : result;
+ GOTO(out, tot_bytes);
+ }
+
+ tot_bytes += result;
+ file_offset += result;
+ iov_left -= result;
+ user_addr += result;