Merge tag 'nfs-for-4.12-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable bugfixes:
   - Fix use after free in write error path
   - Use GFP_NOIO for two allocations in writeback
   - Fix a hang in OPEN related to server reboot
   - Check the result of nfs4_pnfs_ds_connect
   - Fix an rcu lock leak

  Features:
   - Removal of the unmaintained and unused OSD pNFS layout
   - Cleanup and removal of lots of unnecessary dprintk()s
   - Cleanup and removal of some memory failure paths now that GFP_NOFS
     is guaranteed to never fail.
   - Remove the v3-only data server limitation on pNFS/flexfiles

  Bugfixes:
   - RPC/RDMA connection handling bugfixes
   - Copy offload: fixes to ensure the copied data is COMMITed to disk.
   - Readdir: switch back to using the ->iterate VFS interface
   - File locking fixes from Ben Coddington
   - Various use-after-free and deadlock issues in pNFS
   - Write path bugfixes"

* tag 'nfs-for-4.12-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (89 commits)
  pNFS/flexfiles: Always attempt to call layoutstats when flexfiles is enabled
  NFSv4.1: Work around a Linux server bug...
  NFS append COMMIT after synchronous COPY
  NFSv4: Fix exclusive create attributes encoding
  NFSv4: Fix an rcu lock leak
  nfs: use kmap/kunmap directly
  NFS: always treat the invocation of nfs_getattr as cache hit when noac is on
  Fix nfs_client refcounting if kmalloc fails in nfs4_proc_exchange_id and nfs4_proc_async_renew
  NFSv4.1: RECLAIM_COMPLETE must handle NFS4ERR_CONN_NOT_BOUND_TO_SESSION
  pNFS: Fix NULL dereference in pnfs_generic_alloc_ds_commits
  pNFS: Fix a typo in pnfs_generic_alloc_ds_commits
  pNFS: Fix a deadlock when coalescing writes and returning the layout
  pNFS: Don't clear the layout return info if there are segments to return
  pNFS: Ensure we commit the layout if it has been invalidated
  pNFS: Don't send COMMITs to the DSes if the server invalidated our layout
  pNFS/flexfiles: Fix up the ff_layout_write_pagelist failure path
  pNFS: Ensure we check layout validity before marking it for return
  NFS4.1 handle interrupted slot reuse from ERR_DELAY
  NFSv4: check return value of xdr_inline_decode
  nfs/filelayout: fix NULL pointer dereference in fl_pnfs_update_layout()
  ...

1 files changed, 24 insertions, 80 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index f92ba8d..32ccd77 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -57,7 +57,7 @@ static void nfs_readdir_clear_array(struct page*);
 const struct file_operations nfs_dir_operations = {
 	.llseek		= nfs_llseek_dir,
 	.read		= generic_read_dir,
-	.iterate_shared	= nfs_readdir,
+	.iterate	= nfs_readdir,
 	.open		= nfs_opendir,
 	.release	= nfs_closedir,
 	.fsync		= nfs_fsync_dir,
@@ -145,7 +145,6 @@ struct nfs_cache_array_entry {
 };
 
 struct nfs_cache_array {
-	atomic_t refcount;
 	int size;
 	int eof_index;
 	u64 last_cookie;
@@ -171,27 +170,6 @@ typedef struct {
 } nfs_readdir_descriptor_t;
 
 /*
- * The caller is responsible for calling nfs_readdir_release_array(page)
- */
-static
-struct nfs_cache_array *nfs_readdir_get_array(struct page *page)
-{
-	void *ptr;
-	if (page == NULL)
-		return ERR_PTR(-EIO);
-	ptr = kmap(page);
-	if (ptr == NULL)
-		return ERR_PTR(-ENOMEM);
-	return ptr;
-}
-
-static
-void nfs_readdir_release_array(struct page *page)
-{
-	kunmap(page);
-}
-
-/*
  * we are freeing strings created by nfs_add_to_readdir_array()
  */
 static
@@ -201,18 +179,9 @@ void nfs_readdir_clear_array(struct page *page)
 	int i;
 
 	array = kmap_atomic(page);
-	if (atomic_dec_and_test(&array->refcount))
-		for (i = 0; i < array->size; i++)
-			kfree(array->array[i].string.name);
-	kunmap_atomic(array);
-}
-
-static bool grab_page(struct page *page)
-{
-	struct nfs_cache_array *array = kmap_atomic(page);
-	bool res = atomic_inc_not_zero(&array->refcount);
+	for (i = 0; i < array->size; i++)
+		kfree(array->array[i].string.name);
 	kunmap_atomic(array);
-	return res;
 }
 
 /*
@@ -239,13 +208,10 @@ int nfs_readdir_make_qstr(struct qstr *string, const char *name, unsigned int le
 static
 int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
 {
-	struct nfs_cache_array *array = nfs_readdir_get_array(page);
+	struct nfs_cache_array *array = kmap(page);
 	struct nfs_cache_array_entry *cache_entry;
 	int ret;
 
-	if (IS_ERR(array))
-		return PTR_ERR(array);
-
 	cache_entry = &array->array[array->size];
 
 	/* Check that this entry lies within the page bounds */
@@ -264,7 +230,7 @@ int nfs_readdir_add_to_array(struct nfs_entry *entry, struct page *page)
 	if (entry->eof != 0)
 		array->eof_index = array->size;
 out:
-	nfs_readdir_release_array(page);
+	kunmap(page);
 	return ret;
 }
 
@@ -353,11 +319,7 @@ int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
 	struct nfs_cache_array *array;
 	int status;
 
-	array = nfs_readdir_get_array(desc->page);
-	if (IS_ERR(array)) {
-		status = PTR_ERR(array);
-		goto out;
-	}
+	array = kmap(desc->page);
 
 	if (*desc->dir_cookie == 0)
 		status = nfs_readdir_search_for_pos(array, desc);
@@ -369,8 +331,7 @@ int nfs_readdir_search_array(nfs_readdir_descriptor_t *desc)
 		desc->current_index += array->size;
 		desc->page_index++;
 	}
-	nfs_readdir_release_array(desc->page);
-out:
+	kunmap(desc->page);
 	return status;
 }
 
@@ -606,13 +567,10 @@ int nfs_readdir_page_filler(nfs_readdir_descriptor_t *desc, struct nfs_entry *en
 
 out_nopages:
 	if (count == 0 || (status == -EBADCOOKIE && entry->eof != 0)) {
-		array = nfs_readdir_get_array(page);
-		if (!IS_ERR(array)) {
-			array->eof_index = array->size;
-			status = 0;
-			nfs_readdir_release_array(page);
-		} else
-			status = PTR_ERR(array);
+		array = kmap(page);
+		array->eof_index = array->size;
+		status = 0;
+		kunmap(page);
 	}
 
 	put_page(scratch);
@@ -674,13 +632,8 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
 		goto out;
 	}
 
-	array = nfs_readdir_get_array(page);
-	if (IS_ERR(array)) {
-		status = PTR_ERR(array);
-		goto out_label_free;
-	}
+	array = kmap(page);
 	memset(array, 0, sizeof(struct nfs_cache_array));
-	atomic_set(&array->refcount, 1);
 	array->eof_index = -1;
 
 	status = nfs_readdir_alloc_pages(pages, array_size);
@@ -703,8 +656,7 @@ int nfs_readdir_xdr_to_array(nfs_readdir_descriptor_t *desc, struct page *page,
 
 	nfs_readdir_free_pages(pages, array_size);
 out_release_array:
-	nfs_readdir_release_array(page);
-out_label_free:
+	kunmap(page);
 	nfs4_label_free(entry.label);
 out:
 	nfs_free_fattr(entry.fattr);
@@ -743,7 +695,8 @@ int nfs_readdir_filler(nfs_readdir_descriptor_t *desc, struct page* page)
 static
 void cache_page_release(nfs_readdir_descriptor_t *desc)
 {
-	nfs_readdir_clear_array(desc->page);
+	if (!desc->page->mapping)
+		nfs_readdir_clear_array(desc->page);
 	put_page(desc->page);
 	desc->page = NULL;
 }
@@ -751,16 +704,8 @@ void cache_page_release(nfs_readdir_descriptor_t *desc)
 static
 struct page *get_cache_page(nfs_readdir_descriptor_t *desc)
 {
-	struct page *page;
-
-	for (;;) {
-		page = read_cache_page(desc->file->f_mapping,
+	return read_cache_page(desc->file->f_mapping,
 			desc->page_index, (filler_t *)nfs_readdir_filler, desc);
-		if (IS_ERR(page) || grab_page(page))
-			break;
-		put_page(page);
-	}
-	return page;
 }
 
 /*
@@ -809,12 +754,7 @@ int nfs_do_filldir(nfs_readdir_descriptor_t *desc)
 	struct nfs_cache_array *array = NULL;
 	struct nfs_open_dir_context *ctx = file->private_data;
 
-	array = nfs_readdir_get_array(desc->page);
-	if (IS_ERR(array)) {
-		res = PTR_ERR(array);
-		goto out;
-	}
-
+	array = kmap(desc->page);
 	for (i = desc->cache_entry_index; i < array->size; i++) {
 		struct nfs_cache_array_entry *ent;
 
@@ -835,8 +775,7 @@ int nfs_do_filldir(nfs_readdir_descriptor_t *desc)
 	if (array->eof_index >= 0)
 		desc->eof = 1;
 
-	nfs_readdir_release_array(desc->page);
-out:
+	kunmap(desc->page);
 	cache_page_release(desc);
 	dfprintk(DIRCACHE, "NFS: nfs_do_filldir() filling ended @ cookie %Lu; returning = %d\n",
 			(unsigned long long)*desc->dir_cookie, res);
@@ -966,11 +905,13 @@ out:
 
 static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
 {
+	struct inode *inode = file_inode(filp);
 	struct nfs_open_dir_context *dir_ctx = filp->private_data;
 
 	dfprintk(FILE, "NFS: llseek dir(%pD2, %lld, %d)\n",
 			filp, offset, whence);
 
+	inode_lock(inode);
 	switch (whence) {
 		case 1:
 			offset += filp->f_pos;
@@ -978,13 +919,16 @@ static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
 			if (offset >= 0)
 				break;
 		default:
-			return -EINVAL;
+			offset = -EINVAL;
+			goto out;
 	}
 	if (offset != filp->f_pos) {
 		filp->f_pos = offset;
 		dir_ctx->dir_cookie = 0;
 		dir_ctx->duped = 0;
 	}
+out:
+	inode_unlock(inode);
 	return offset;
 }