struct afs_fid fids[50];
};
+/*
+ * Drop the refs that we're holding on the pages we were reading into. We've
+ * got refs on the first nr_pages pages.
+ */
+static void afs_dir_read_cleanup(struct afs_read *req)
+{
+ struct address_space *mapping = req->vnode->vfs_inode.i_mapping;
+ struct page *page;
+ pgoff_t last = req->nr_pages - 1;
+
+ XA_STATE(xas, &mapping->i_pages, 0);
+
+ if (unlikely(!req->nr_pages))
+ return;
+
+ rcu_read_lock();
+ xas_for_each(&xas, page, last) {
+ if (xas_retry(&xas, page))
+ continue;
+ BUG_ON(xa_is_value(page));
+ BUG_ON(PageCompound(page));
+ ASSERTCMP(page->mapping, ==, mapping);
+
+ put_page(page);
+ }
+
+ rcu_read_unlock();
+}
+
/*
* check that a directory page is valid
*/
qty /= sizeof(union afs_xdr_dir_block);
/* check them */
- dbuf = kmap(page);
+ dbuf = kmap_atomic(page);
for (tmp = 0; tmp < qty; tmp++) {
if (dbuf->blocks[tmp].hdr.magic != AFS_DIR_MAGIC) {
printk("kAFS: %s(%lx): bad magic %d/%d is %04hx\n",
((u8 *)&dbuf->blocks[tmp])[AFS_DIR_BLOCK_SIZE - 1] = 0;
}
- kunmap(page);
+ kunmap_atomic(dbuf);
checked:
afs_stat_v(dvnode, n_read_dir);
}
/*
- * Check the contents of a directory that we've just read.
+ * Dump the contents of a directory.
*/
-static bool afs_dir_check_pages(struct afs_vnode *dvnode, struct afs_read *req)
+static void afs_dir_dump(struct afs_vnode *dvnode, struct afs_read *req)
{
struct afs_xdr_dir_page *dbuf;
- unsigned int i, j, qty = PAGE_SIZE / sizeof(union afs_xdr_dir_block);
+ struct address_space *mapping = dvnode->vfs_inode.i_mapping;
+ struct page *page;
+ unsigned int i, qty = PAGE_SIZE / sizeof(union afs_xdr_dir_block);
+ pgoff_t last = req->nr_pages - 1;
- for (i = 0; i < req->nr_pages; i++)
- if (!afs_dir_check_page(dvnode, req->pages[i], req->actual_len))
- goto bad;
- return true;
+ XA_STATE(xas, &mapping->i_pages, 0);
-bad:
- pr_warn("DIR %llx:%llx f=%llx l=%llx al=%llx r=%llx\n",
+ pr_warn("DIR %llx:%llx f=%llx l=%llx al=%llx\n",
dvnode->fid.vid, dvnode->fid.vnode,
- req->file_size, req->len, req->actual_len, req->remain);
- pr_warn("DIR %llx %x %x %x\n",
- req->pos, req->index, req->nr_pages, req->offset);
+ req->file_size, req->len, req->actual_len);
+ pr_warn("DIR %llx %x %zx %zx\n",
+ req->pos, req->nr_pages,
+ req->iter->iov_offset, iov_iter_count(req->iter));
- for (i = 0; i < req->nr_pages; i++) {
- dbuf = kmap(req->pages[i]);
- for (j = 0; j < qty; j++) {
- union afs_xdr_dir_block *block = &dbuf->blocks[j];
+ xas_for_each(&xas, page, last) {
+ if (xas_retry(&xas, page))
+ continue;
+
+ BUG_ON(PageCompound(page));
+ BUG_ON(page->mapping != mapping);
+
+ dbuf = kmap_atomic(page);
+ for (i = 0; i < qty; i++) {
+ union afs_xdr_dir_block *block = &dbuf->blocks[i];
- pr_warn("[%02x] %32phN\n", i * qty + j, block);
+ pr_warn("[%02lx] %32phN\n", page->index * qty + i, block);
}
- kunmap(req->pages[i]);
+ kunmap_atomic(dbuf);
}
- return false;
+}
+
+/*
+ * Check all the pages in a directory. All the pages are held pinned.
+ */
+static int afs_dir_check(struct afs_vnode *dvnode, struct afs_read *req)
+{
+ struct address_space *mapping = dvnode->vfs_inode.i_mapping;
+ struct page *page;
+ pgoff_t last = req->nr_pages - 1;
+ int ret = 0;
+
+ XA_STATE(xas, &mapping->i_pages, 0);
+
+ if (unlikely(!req->nr_pages))
+ return 0;
+
+ rcu_read_lock();
+ xas_for_each(&xas, page, last) {
+ if (xas_retry(&xas, page))
+ continue;
+
+ BUG_ON(PageCompound(page));
+ BUG_ON(page->mapping != mapping);
+
+ if (!afs_dir_check_page(dvnode, page, req->file_size)) {
+ afs_dir_dump(dvnode, req);
+ ret = -EIO;
+ break;
+ }
+ }
+
+ rcu_read_unlock();
+ return ret;
}
/*
{
struct afs_read *req;
loff_t i_size;
- int nr_pages, nr_inline, i, n;
- int ret = -ENOMEM;
+ int nr_pages, i, n;
+ int ret;
+
+ _enter("");
-retry:
+ req = kzalloc(sizeof(*req), GFP_KERNEL);
+ if (!req)
+ return ERR_PTR(-ENOMEM);
+
+ refcount_set(&req->usage, 1);
+ req->vnode = dvnode;
+ req->key = key_get(key);
+ req->cleanup = afs_dir_read_cleanup;
+
+expand:
i_size = i_size_read(&dvnode->vfs_inode);
- if (i_size < 2048)
- return ERR_PTR(afs_bad(dvnode, afs_file_error_dir_small));
+ if (i_size < 2048) {
+ ret = afs_bad(dvnode, afs_file_error_dir_small);
+ goto error;
+ }
if (i_size > 2048 * 1024) {
trace_afs_file_error(dvnode, -EFBIG, afs_file_error_dir_big);
- return ERR_PTR(-EFBIG);
+ ret = -EFBIG;
+ goto error;
}
_enter("%llu", i_size);
- /* Get a request record to hold the page list. We want to hold it
- * inline if we can, but we don't want to make an order 1 allocation.
- */
nr_pages = (i_size + PAGE_SIZE - 1) / PAGE_SIZE;
- nr_inline = nr_pages;
- if (nr_inline > (PAGE_SIZE - sizeof(*req)) / sizeof(struct page *))
- nr_inline = 0;
- req = kzalloc(struct_size(req, array, nr_inline), GFP_KERNEL);
- if (!req)
- return ERR_PTR(-ENOMEM);
-
- refcount_set(&req->usage, 1);
- req->key = key_get(key);
- req->nr_pages = nr_pages;
req->actual_len = i_size; /* May change */
req->len = nr_pages * PAGE_SIZE; /* We can ask for more than there is */
req->data_version = dvnode->status.data_version; /* May change */
- if (nr_inline > 0) {
- req->pages = req->array;
- } else {
- req->pages = kcalloc(nr_pages, sizeof(struct page *),
- GFP_KERNEL);
- if (!req->pages)
- goto error;
- }
+ iov_iter_xarray(&req->def_iter, READ, &dvnode->vfs_inode.i_mapping->i_pages,
+ 0, i_size);
+ req->iter = &req->def_iter;
- /* Get a list of all the pages that hold or will hold the directory
- * content. We need to fill in any gaps that we might find where the
- * memory reclaimer has been at work. If there are any gaps, we will
+ /* Fill in any gaps that we might find where the memory reclaimer has
+ * been at work and pin all the pages. If there are any gaps, we will
* need to reread the entire directory contents.
*/
- i = 0;
- do {
+ i = req->nr_pages;
+ while (i < nr_pages) {
+ struct page *pages[8], *page;
+
n = find_get_pages_contig(dvnode->vfs_inode.i_mapping, i,
- req->nr_pages - i,
- req->pages + i);
- _debug("find %u at %u/%u", n, i, req->nr_pages);
+ min_t(unsigned int, nr_pages - i,
+ ARRAY_SIZE(pages)),
+ pages);
+ _debug("find %u at %u/%u", n, i, nr_pages);
+
if (n == 0) {
gfp_t gfp = dvnode->vfs_inode.i_mapping->gfp_mask;
afs_stat_v(dvnode, n_inval);
ret = -ENOMEM;
- req->pages[i] = __page_cache_alloc(gfp);
- if (!req->pages[i])
+ page = __page_cache_alloc(gfp);
+ if (!page)
goto error;
- ret = add_to_page_cache_lru(req->pages[i],
+ ret = add_to_page_cache_lru(page,
dvnode->vfs_inode.i_mapping,
i, gfp);
if (ret < 0)
goto error;
- attach_page_private(req->pages[i], (void *)1);
- unlock_page(req->pages[i]);
+ attach_page_private(page, (void *)1);
+ unlock_page(page);
+ req->nr_pages++;
i++;
} else {
+ req->nr_pages += n;
i += n;
}
- } while (i < req->nr_pages);
+ }
/* If we're going to reload, we need to lock all the pages to prevent
* races.
task_io_account_read(PAGE_SIZE * req->nr_pages);
- if (req->len < req->file_size)
- goto content_has_grown;
+ if (req->len < req->file_size) {
+ /* The content has grown, so we need to expand the
+ * buffer.
+ */
+ up_write(&dvnode->validate_lock);
+ goto expand;
+ }
/* Validate the data we just read. */
- ret = -EIO;
- if (!afs_dir_check_pages(dvnode, req))
+ ret = afs_dir_check(dvnode, req);
+ if (ret < 0)
goto error_unlock;
// TODO: Trim excess pages
afs_put_read(req);
_leave(" = %d", ret);
return ERR_PTR(ret);
-
-content_has_grown:
- up_write(&dvnode->validate_lock);
- afs_put_read(req);
- goto retry;
}
/*
struct afs_read *req;
struct page *page;
unsigned blkoff, limit;
+ void __rcu **slot;
int ret;
_enter("{%lu},%u,,", dir->i_ino, (unsigned)ctx->pos);
blkoff = ctx->pos & ~(sizeof(union afs_xdr_dir_block) - 1);
/* Fetch the appropriate page from the directory and re-add it
- * to the LRU.
+ * to the LRU. We have all the pages pinned with an extra ref.
*/
- page = req->pages[blkoff / PAGE_SIZE];
+ rcu_read_lock();
+ page = NULL;
+ slot = radix_tree_lookup_slot(&dvnode->vfs_inode.i_mapping->i_pages,
+ blkoff / PAGE_SIZE);
+ if (slot)
+ page = radix_tree_deref_slot(slot);
+ rcu_read_unlock();
if (!page) {
ret = afs_bad(dvnode, afs_file_error_dir_missing_page);
break;
git.samba.org / sfrench / cifs-2.6.git / blobdiff