forked from Minki/linux
new helper: iov_iter_get_pages_alloc()
same as iov_iter_get_pages(), except that pages array is allocated (kmalloc if possible, vmalloc if that fails) and left for caller to free. Lustre and NFS ->direct_IO() switched to it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro
parent
f67da30c1d
commit
91f79c43d1
@ -218,14 +218,11 @@ static void ll_free_user_pages(struct page **pages, int npages, int do_dirty)
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int i;
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for (i = 0; i < npages; i++) {
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if (pages[i] == NULL)
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break;
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if (do_dirty)
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set_page_dirty_lock(pages[i]);
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page_cache_release(pages[i]);
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}
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OBD_FREE_LARGE(pages, npages * sizeof(*pages));
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kvfree(pages);
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}
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ssize_t ll_direct_rw_pages(const struct lu_env *env, struct cl_io *io,
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@ -370,10 +367,9 @@ static ssize_t ll_direct_IO_26(int rw, struct kiocb *iocb,
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struct file *file = iocb->ki_filp;
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struct inode *inode = file->f_mapping->host;
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struct ccc_object *obj = cl_inode2ccc(inode);
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long count = iov_iter_count(iter);
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long tot_bytes = 0, result = 0;
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ssize_t count = iov_iter_count(iter);
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ssize_t tot_bytes = 0, result = 0;
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struct ll_inode_info *lli = ll_i2info(inode);
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unsigned long seg = 0;
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long size = MAX_DIO_SIZE;
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int refcheck;
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@ -407,63 +403,49 @@ static ssize_t ll_direct_IO_26(int rw, struct kiocb *iocb,
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mutex_lock(&inode->i_mutex);
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LASSERT(obj->cob_transient_pages == 0);
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for (seg = 0; seg < iter->nr_segs; seg++) {
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long iov_left = iter->iov[seg].iov_len;
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unsigned long user_addr = (unsigned long)iter->iov[seg].iov_base;
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while (iov_iter_count(iter)) {
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struct page **pages;
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size_t offs;
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count = min_t(size_t, iov_iter_count(iter), size);
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if (rw == READ) {
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if (file_offset >= i_size_read(inode))
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break;
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if (file_offset + iov_left > i_size_read(inode))
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iov_left = i_size_read(inode) - file_offset;
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if (file_offset + count > i_size_read(inode))
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count = i_size_read(inode) - file_offset;
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}
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while (iov_left > 0) {
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struct page **pages;
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int page_count, max_pages = 0;
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long bytes;
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bytes = min(size, iov_left);
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page_count = ll_get_user_pages(rw, user_addr, bytes,
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&pages, &max_pages);
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if (likely(page_count > 0)) {
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if (unlikely(page_count < max_pages))
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bytes = page_count << PAGE_CACHE_SHIFT;
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result = ll_direct_IO_26_seg(env, io, rw, inode,
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file->f_mapping,
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bytes, file_offset,
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pages, page_count);
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ll_free_user_pages(pages, max_pages, rw==READ);
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} else if (page_count == 0) {
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GOTO(out, result = -EFAULT);
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} else {
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result = page_count;
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}
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if (unlikely(result <= 0)) {
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/* If we can't allocate a large enough buffer
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* for the request, shrink it to a smaller
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* PAGE_SIZE multiple and try again.
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* We should always be able to kmalloc for a
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* page worth of page pointers = 4MB on i386. */
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if (result == -ENOMEM &&
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size > (PAGE_CACHE_SIZE / sizeof(*pages)) *
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PAGE_CACHE_SIZE) {
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size = ((((size / 2) - 1) |
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~CFS_PAGE_MASK) + 1) &
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CFS_PAGE_MASK;
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CDEBUG(D_VFSTRACE,"DIO size now %lu\n",
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size);
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continue;
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}
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GOTO(out, result);
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}
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tot_bytes += result;
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file_offset += result;
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iov_left -= result;
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user_addr += result;
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result = iov_iter_get_pages_alloc(iter, &pages, count, &offs);
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if (likely(result > 0)) {
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int n = (result + offs + PAGE_SIZE - 1) / PAGE_SIZE;
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result = ll_direct_IO_26_seg(env, io, rw, inode,
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file->f_mapping,
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result, file_offset,
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pages, n);
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ll_free_user_pages(pages, n, rw==READ);
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}
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if (unlikely(result <= 0)) {
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/* If we can't allocate a large enough buffer
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* for the request, shrink it to a smaller
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* PAGE_SIZE multiple and try again.
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* We should always be able to kmalloc for a
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* page worth of page pointers = 4MB on i386. */
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if (result == -ENOMEM &&
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size > (PAGE_CACHE_SIZE / sizeof(*pages)) *
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PAGE_CACHE_SIZE) {
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size = ((((size / 2) - 1) |
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~CFS_PAGE_MASK) + 1) &
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CFS_PAGE_MASK;
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CDEBUG(D_VFSTRACE,"DIO size now %lu\n",
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size);
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continue;
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}
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GOTO(out, result);
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}
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iov_iter_advance(iter, result);
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tot_bytes += result;
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file_offset += result;
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}
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out:
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LASSERT(obj->cob_transient_pages == 0);
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286
fs/nfs/direct.c
286
fs/nfs/direct.c
@ -322,60 +322,37 @@ static const struct nfs_pgio_completion_ops nfs_direct_read_completion_ops = {
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* handled automatically by nfs_direct_read_result(). Otherwise, if
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* no requests have been sent, just return an error.
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*/
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static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *desc,
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const struct iovec *iov,
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loff_t pos, bool uio)
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static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
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struct iov_iter *iter,
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loff_t pos)
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{
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struct nfs_direct_req *dreq = desc->pg_dreq;
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struct nfs_open_context *ctx = dreq->ctx;
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struct inode *inode = ctx->dentry->d_inode;
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unsigned long user_addr = (unsigned long)iov->iov_base;
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size_t count = iov->iov_len;
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size_t rsize = NFS_SERVER(inode)->rsize;
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unsigned int pgbase;
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int result;
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ssize_t started = 0;
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struct page **pagevec = NULL;
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unsigned int npages;
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struct nfs_pageio_descriptor desc;
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struct inode *inode = dreq->inode;
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ssize_t result = -EINVAL;
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size_t requested_bytes = 0;
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size_t rsize = max_t(size_t, NFS_SERVER(inode)->rsize, PAGE_SIZE);
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do {
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NFS_PROTO(dreq->inode)->read_pageio_init(&desc, dreq->inode,
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&nfs_direct_read_completion_ops);
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get_dreq(dreq);
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desc.pg_dreq = dreq;
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atomic_inc(&inode->i_dio_count);
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while (iov_iter_count(iter)) {
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struct page **pagevec;
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size_t bytes;
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int i;
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size_t pgbase;
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unsigned npages, i;
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pgbase = user_addr & ~PAGE_MASK;
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bytes = min(max_t(size_t, rsize, PAGE_SIZE), count);
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result = -ENOMEM;
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npages = nfs_page_array_len(pgbase, bytes);
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if (!pagevec)
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pagevec = kmalloc(npages * sizeof(struct page *),
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GFP_KERNEL);
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if (!pagevec)
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result = iov_iter_get_pages_alloc(iter, &pagevec,
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rsize, &pgbase);
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if (result < 0)
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break;
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if (uio) {
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down_read(¤t->mm->mmap_sem);
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result = get_user_pages(current, current->mm, user_addr,
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npages, 1, 0, pagevec, NULL);
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up_read(¤t->mm->mmap_sem);
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if (result < 0)
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break;
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} else {
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WARN_ON(npages != 1);
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result = get_kernel_page(user_addr, 1, pagevec);
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if (WARN_ON(result != 1))
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break;
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}
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if ((unsigned)result < npages) {
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bytes = result * PAGE_SIZE;
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if (bytes <= pgbase) {
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nfs_direct_release_pages(pagevec, result);
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break;
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}
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bytes -= pgbase;
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npages = result;
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}
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bytes = result;
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iov_iter_advance(iter, bytes);
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npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE;
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for (i = 0; i < npages; i++) {
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struct nfs_page *req;
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unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
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@ -389,55 +366,21 @@ static ssize_t nfs_direct_read_schedule_segment(struct nfs_pageio_descriptor *de
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}
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req->wb_index = pos >> PAGE_SHIFT;
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req->wb_offset = pos & ~PAGE_MASK;
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if (!nfs_pageio_add_request(desc, req)) {
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result = desc->pg_error;
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if (!nfs_pageio_add_request(&desc, req)) {
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result = desc.pg_error;
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nfs_release_request(req);
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break;
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}
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pgbase = 0;
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bytes -= req_len;
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started += req_len;
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user_addr += req_len;
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requested_bytes += req_len;
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pos += req_len;
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count -= req_len;
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dreq->bytes_left -= req_len;
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}
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/* The nfs_page now hold references to these pages */
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nfs_direct_release_pages(pagevec, npages);
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} while (count != 0 && result >= 0);
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kfree(pagevec);
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if (started)
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return started;
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return result < 0 ? (ssize_t) result : -EFAULT;
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}
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static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
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struct iov_iter *iter,
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loff_t pos, bool uio)
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{
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struct nfs_pageio_descriptor desc;
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struct inode *inode = dreq->inode;
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ssize_t result = -EINVAL;
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size_t requested_bytes = 0;
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unsigned long seg;
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NFS_PROTO(dreq->inode)->read_pageio_init(&desc, dreq->inode,
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&nfs_direct_read_completion_ops);
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get_dreq(dreq);
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desc.pg_dreq = dreq;
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atomic_inc(&inode->i_dio_count);
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for (seg = 0; seg < iter->nr_segs; seg++) {
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const struct iovec *vec = &iter->iov[seg];
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result = nfs_direct_read_schedule_segment(&desc, vec, pos, uio);
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kvfree(pagevec);
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if (result < 0)
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break;
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requested_bytes += result;
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if ((size_t)result < vec->iov_len)
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break;
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pos += vec->iov_len;
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}
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nfs_pageio_complete(&desc);
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@ -521,7 +464,7 @@ ssize_t nfs_file_direct_read(struct kiocb *iocb, struct iov_iter *iter,
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dreq->iocb = iocb;
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NFS_I(inode)->read_io += count;
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result = nfs_direct_read_schedule_iovec(dreq, iter, pos, uio);
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result = nfs_direct_read_schedule_iovec(dreq, iter, pos);
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mutex_unlock(&inode->i_mutex);
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@ -677,109 +620,6 @@ static void nfs_direct_write_complete(struct nfs_direct_req *dreq, struct inode
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}
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#endif
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/*
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* NB: Return the value of the first error return code. Subsequent
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* errors after the first one are ignored.
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*/
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/*
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* For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE
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* operation. If nfs_writedata_alloc() or get_user_pages() fails,
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* bail and stop sending more writes. Write length accounting is
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* handled automatically by nfs_direct_write_result(). Otherwise, if
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* no requests have been sent, just return an error.
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*/
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static ssize_t nfs_direct_write_schedule_segment(struct nfs_pageio_descriptor *desc,
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const struct iovec *iov,
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loff_t pos, bool uio)
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{
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struct nfs_direct_req *dreq = desc->pg_dreq;
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struct nfs_open_context *ctx = dreq->ctx;
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struct inode *inode = ctx->dentry->d_inode;
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unsigned long user_addr = (unsigned long)iov->iov_base;
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size_t count = iov->iov_len;
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size_t wsize = NFS_SERVER(inode)->wsize;
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unsigned int pgbase;
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int result;
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ssize_t started = 0;
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struct page **pagevec = NULL;
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unsigned int npages;
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do {
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size_t bytes;
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int i;
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pgbase = user_addr & ~PAGE_MASK;
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bytes = min(max_t(size_t, wsize, PAGE_SIZE), count);
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result = -ENOMEM;
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npages = nfs_page_array_len(pgbase, bytes);
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if (!pagevec)
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pagevec = kmalloc(npages * sizeof(struct page *), GFP_KERNEL);
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if (!pagevec)
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break;
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if (uio) {
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down_read(¤t->mm->mmap_sem);
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result = get_user_pages(current, current->mm, user_addr,
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npages, 0, 0, pagevec, NULL);
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up_read(¤t->mm->mmap_sem);
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if (result < 0)
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break;
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} else {
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WARN_ON(npages != 1);
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result = get_kernel_page(user_addr, 0, pagevec);
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if (WARN_ON(result != 1))
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break;
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}
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if ((unsigned)result < npages) {
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bytes = result * PAGE_SIZE;
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if (bytes <= pgbase) {
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nfs_direct_release_pages(pagevec, result);
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break;
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}
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bytes -= pgbase;
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npages = result;
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}
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for (i = 0; i < npages; i++) {
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struct nfs_page *req;
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unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
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req = nfs_create_request(dreq->ctx, dreq->inode,
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pagevec[i],
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pgbase, req_len);
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if (IS_ERR(req)) {
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result = PTR_ERR(req);
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break;
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}
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nfs_lock_request(req);
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req->wb_index = pos >> PAGE_SHIFT;
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req->wb_offset = pos & ~PAGE_MASK;
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if (!nfs_pageio_add_request(desc, req)) {
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result = desc->pg_error;
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nfs_unlock_and_release_request(req);
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break;
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}
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pgbase = 0;
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bytes -= req_len;
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started += req_len;
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user_addr += req_len;
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pos += req_len;
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count -= req_len;
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dreq->bytes_left -= req_len;
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}
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/* The nfs_page now hold references to these pages */
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nfs_direct_release_pages(pagevec, npages);
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} while (count != 0 && result >= 0);
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kfree(pagevec);
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if (started)
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return started;
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return result < 0 ? (ssize_t) result : -EFAULT;
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}
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static void nfs_direct_write_completion(struct nfs_pgio_header *hdr)
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{
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struct nfs_direct_req *dreq = hdr->dreq;
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@ -859,15 +699,27 @@ static const struct nfs_pgio_completion_ops nfs_direct_write_completion_ops = {
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.completion = nfs_direct_write_completion,
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};
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/*
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* NB: Return the value of the first error return code. Subsequent
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* errors after the first one are ignored.
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*/
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/*
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* For each wsize'd chunk of the user's buffer, dispatch an NFS WRITE
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* operation. If nfs_writedata_alloc() or get_user_pages() fails,
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* bail and stop sending more writes. Write length accounting is
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* handled automatically by nfs_direct_write_result(). Otherwise, if
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* no requests have been sent, just return an error.
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*/
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static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
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struct iov_iter *iter,
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loff_t pos, bool uio)
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loff_t pos)
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{
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struct nfs_pageio_descriptor desc;
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struct inode *inode = dreq->inode;
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ssize_t result = 0;
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size_t requested_bytes = 0;
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unsigned long seg;
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size_t wsize = max_t(size_t, NFS_SERVER(inode)->wsize, PAGE_SIZE);
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NFS_PROTO(inode)->write_pageio_init(&desc, inode, FLUSH_COND_STABLE,
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&nfs_direct_write_completion_ops);
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@ -875,16 +727,50 @@ static ssize_t nfs_direct_write_schedule_iovec(struct nfs_direct_req *dreq,
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get_dreq(dreq);
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atomic_inc(&inode->i_dio_count);
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NFS_I(dreq->inode)->write_io += iov_iter_count(iter);
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for (seg = 0; seg < iter->nr_segs; seg++) {
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const struct iovec *vec = &iter->iov[seg];
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result = nfs_direct_write_schedule_segment(&desc, vec, pos, uio);
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NFS_I(inode)->write_io += iov_iter_count(iter);
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while (iov_iter_count(iter)) {
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struct page **pagevec;
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size_t bytes;
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size_t pgbase;
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unsigned npages, i;
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result = iov_iter_get_pages_alloc(iter, &pagevec,
|
||||
wsize, &pgbase);
|
||||
if (result < 0)
|
||||
break;
|
||||
requested_bytes += result;
|
||||
if ((size_t)result < vec->iov_len)
|
||||
|
||||
bytes = result;
|
||||
iov_iter_advance(iter, bytes);
|
||||
npages = (result + pgbase + PAGE_SIZE - 1) / PAGE_SIZE;
|
||||
for (i = 0; i < npages; i++) {
|
||||
struct nfs_page *req;
|
||||
unsigned int req_len = min_t(size_t, bytes, PAGE_SIZE - pgbase);
|
||||
|
||||
req = nfs_create_request(dreq->ctx, inode,
|
||||
pagevec[i],
|
||||
pgbase, req_len);
|
||||
if (IS_ERR(req)) {
|
||||
result = PTR_ERR(req);
|
||||
break;
|
||||
}
|
||||
nfs_lock_request(req);
|
||||
req->wb_index = pos >> PAGE_SHIFT;
|
||||
req->wb_offset = pos & ~PAGE_MASK;
|
||||
if (!nfs_pageio_add_request(&desc, req)) {
|
||||
result = desc.pg_error;
|
||||
nfs_unlock_and_release_request(req);
|
||||
break;
|
||||
}
|
||||
pgbase = 0;
|
||||
bytes -= req_len;
|
||||
requested_bytes += req_len;
|
||||
pos += req_len;
|
||||
dreq->bytes_left -= req_len;
|
||||
}
|
||||
nfs_direct_release_pages(pagevec, npages);
|
||||
kvfree(pagevec);
|
||||
if (result < 0)
|
||||
break;
|
||||
pos += vec->iov_len;
|
||||
}
|
||||
nfs_pageio_complete(&desc);
|
||||
|
||||
@ -985,7 +871,7 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
|
||||
if (!is_sync_kiocb(iocb))
|
||||
dreq->iocb = iocb;
|
||||
|
||||
result = nfs_direct_write_schedule_iovec(dreq, iter, pos, uio);
|
||||
result = nfs_direct_write_schedule_iovec(dreq, iter, pos);
|
||||
|
||||
if (mapping->nrpages) {
|
||||
invalidate_inode_pages2_range(mapping,
|
||||
|
||||
@ -73,6 +73,8 @@ void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov,
|
||||
unsigned long nr_segs, size_t count);
|
||||
ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages,
|
||||
size_t maxsize, size_t *start);
|
||||
ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages,
|
||||
size_t maxsize, size_t *start);
|
||||
int iov_iter_npages(const struct iov_iter *i, int maxpages);
|
||||
|
||||
static inline size_t iov_iter_count(struct iov_iter *i)
|
||||
|
||||
@ -1,6 +1,8 @@
|
||||
#include <linux/export.h>
|
||||
#include <linux/uio.h>
|
||||
#include <linux/pagemap.h>
|
||||
#include <linux/slab.h>
|
||||
#include <linux/vmalloc.h>
|
||||
|
||||
size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
|
||||
struct iov_iter *i)
|
||||
@ -263,6 +265,44 @@ ssize_t iov_iter_get_pages(struct iov_iter *i,
|
||||
}
|
||||
EXPORT_SYMBOL(iov_iter_get_pages);
|
||||
|
||||
ssize_t iov_iter_get_pages_alloc(struct iov_iter *i,
|
||||
struct page ***pages, size_t maxsize,
|
||||
size_t *start)
|
||||
{
|
||||
size_t offset = i->iov_offset;
|
||||
const struct iovec *iov = i->iov;
|
||||
size_t len;
|
||||
unsigned long addr;
|
||||
void *p;
|
||||
int n;
|
||||
int res;
|
||||
|
||||
len = iov->iov_len - offset;
|
||||
if (len > i->count)
|
||||
len = i->count;
|
||||
if (len > maxsize)
|
||||
len = maxsize;
|
||||
addr = (unsigned long)iov->iov_base + offset;
|
||||
len += *start = addr & (PAGE_SIZE - 1);
|
||||
addr &= ~(PAGE_SIZE - 1);
|
||||
n = (len + PAGE_SIZE - 1) / PAGE_SIZE;
|
||||
|
||||
p = kmalloc(n * sizeof(struct page *), GFP_KERNEL);
|
||||
if (!p)
|
||||
p = vmalloc(n * sizeof(struct page *));
|
||||
if (!p)
|
||||
return -ENOMEM;
|
||||
|
||||
res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, p);
|
||||
if (unlikely(res < 0)) {
|
||||
kvfree(p);
|
||||
return res;
|
||||
}
|
||||
*pages = p;
|
||||
return (res == n ? len : res * PAGE_SIZE) - *start;
|
||||
}
|
||||
EXPORT_SYMBOL(iov_iter_get_pages_alloc);
|
||||
|
||||
int iov_iter_npages(const struct iov_iter *i, int maxpages)
|
||||
{
|
||||
size_t offset = i->iov_offset;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user