Merge tag 'nfs-for-5.7-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

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

  Stable fixes:
   - Fix a page leak in nfs_destroy_unlinked_subrequests()

   - Fix use-after-free issues in nfs_pageio_add_request()

   - Fix new mount code constant_table array definitions

   - finish_automount() requires us to hold 2 refs to the mount record

  Features:
   - Improve the accuracy of telldir/seekdir by using 64-bit cookies
     when possible.

   - Allow one RDMA active connection and several zombie connections to
     prevent blocking if the remote server is unresponsive.

   - Limit the size of the NFS access cache by default

   - Reduce the number of references to credentials that are taken by
     NFS

   - pNFS files and flexfiles drivers now support per-layout segment
     COMMIT lists.

   - Enable partial-file layout segments in the pNFS/flexfiles driver.

   - Add support for CB_RECALL_ANY to the pNFS flexfiles layout type

   - pNFS/flexfiles Report NFS4ERR_DELAY and NFS4ERR_GRACE errors from
     the DS using the layouterror mechanism.

  Bugfixes and cleanups:
   - SUNRPC: Fix krb5p regressions

   - Don't specify NFS version in "UDP not supported" error

   - nfsroot: set tcp as the default transport protocol

   - pnfs: Return valid stateids in nfs_layout_find_inode_by_stateid()

   - alloc_nfs_open_context() must use the file cred when available

   - Fix locking when dereferencing the delegation cred

   - Fix memory leaks in O_DIRECT when nfs_get_lock_context() fails

   - Various clean ups of the NFS O_DIRECT commit code

   - Clean up RDMA connect/disconnect

   - Replace zero-length arrays with C99-style flexible arrays"

* tag 'nfs-for-5.7-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (86 commits)
  NFS: Clean up process of marking inode stale.
  SUNRPC: Don't start a timer on an already queued rpc task
  NFS/pnfs: Reference the layout cred in pnfs_prepare_layoutreturn()
  NFS/pnfs: Fix dereference of layout cred in pnfs_layoutcommit_inode()
  NFS: Beware when dereferencing the delegation cred
  NFS: Add a module parameter to set nfs_mountpoint_expiry_timeout
  NFS: finish_automount() requires us to hold 2 refs to the mount record
  NFS: Fix a few constant_table array definitions
  NFS: Try to join page groups before an O_DIRECT retransmission
  NFS: Refactor nfs_lock_and_join_requests()
  NFS: Reverse the submission order of requests in __nfs_pageio_add_request()
  NFS: Clean up nfs_lock_and_join_requests()
  NFS: Remove the redundant function nfs_pgio_has_mirroring()
  NFS: Fix memory leaks in nfs_pageio_stop_mirroring()
  NFS: Fix a request reference leak in nfs_direct_write_clear_reqs()
  NFS: Fix use-after-free issues in nfs_pageio_add_request()
  NFS: Fix races nfs_page_group_destroy() vs nfs_destroy_unlinked_subrequests()
  NFS: Fix a page leak in nfs_destroy_unlinked_subrequests()
  NFS: Remove unused FLUSH_SYNC support in nfs_initiate_pgio()
  pNFS/flexfiles: Specify the layout segment range in LAYOUTGET
  ...

1 files changed, 50 insertions, 29 deletions

diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
index d4b839b6cf89..5a331da5f55a 100644
--- a/fs/nfs/dir.c
+++ b/fs/nfs/dir.c
@@ -141,10 +141,9 @@ struct nfs_cache_array {
 	int size;
 	int eof_index;
 	u64 last_cookie;
-	struct nfs_cache_array_entry array[0];
+	struct nfs_cache_array_entry array[];
 };
 
-typedef int (*decode_dirent_t)(struct xdr_stream *, struct nfs_entry *, bool);
 typedef struct {
 	struct file	*file;
 	struct page	*page;
@@ -153,7 +152,7 @@ typedef struct {
 	u64		*dir_cookie;
 	u64		last_cookie;
 	loff_t		current_index;
-	decode_dirent_t	decode;
+	loff_t		prev_index;
 
 	unsigned long	dir_verifier;
 	unsigned long	timestamp;
@@ -240,6 +239,25 @@ out:
 	return ret;
 }
 
+static inline
+int is_32bit_api(void)
+{
+#ifdef CONFIG_COMPAT
+	return in_compat_syscall();
+#else
+	return (BITS_PER_LONG == 32);
+#endif
+}
+
+static
+bool nfs_readdir_use_cookie(const struct file *filp)
+{
+	if ((filp->f_mode & FMODE_32BITHASH) ||
+	    (!(filp->f_mode & FMODE_64BITHASH) && is_32bit_api()))
+		return false;
+	return true;
+}
+
 static
 int nfs_readdir_search_for_pos(struct nfs_cache_array *array, nfs_readdir_descriptor_t *desc)
 {
@@ -289,7 +307,7 @@ int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_des
 			    !nfs_readdir_inode_mapping_valid(nfsi)) {
 				ctx->duped = 0;
 				ctx->attr_gencount = nfsi->attr_gencount;
-			} else if (new_pos < desc->ctx->pos) {
+			} else if (new_pos < desc->prev_index) {
 				if (ctx->duped > 0
 				    && ctx->dup_cookie == *desc->dir_cookie) {
 					if (printk_ratelimit()) {
@@ -305,7 +323,11 @@ int nfs_readdir_search_for_cookie(struct nfs_cache_array *array, nfs_readdir_des
 				ctx->dup_cookie = *desc->dir_cookie;
 				ctx->duped = -1;
 			}
-			desc->ctx->pos = new_pos;
+			if (nfs_readdir_use_cookie(desc->file))
+				desc->ctx->pos = *desc->dir_cookie;
+			else
+				desc->ctx->pos = new_pos;
+			desc->prev_index = new_pos;
 			desc->cache_entry_index = i;
 			return 0;
 		}
@@ -376,9 +398,10 @@ error:
 static int xdr_decode(nfs_readdir_descriptor_t *desc,
 		      struct nfs_entry *entry, struct xdr_stream *xdr)
 {
+	struct inode *inode = file_inode(desc->file);
 	int error;
 
-	error = desc->decode(xdr, entry, desc->plus);
+	error = NFS_PROTO(inode)->decode_dirent(xdr, entry, desc->plus);
 	if (error)
 		return error;
 	entry->fattr->time_start = desc->timestamp;
@@ -756,6 +779,7 @@ int readdir_search_pagecache(nfs_readdir_descriptor_t *desc)
 
 	if (desc->page_index == 0) {
 		desc->current_index = 0;
+		desc->prev_index = 0;
 		desc->last_cookie = 0;
 	}
 	do {
@@ -786,11 +810,14 @@ int nfs_do_filldir(nfs_readdir_descriptor_t *desc)
 			desc->eof = true;
 			break;
 		}
-		desc->ctx->pos++;
 		if (i < (array->size-1))
 			*desc->dir_cookie = array->array[i+1].cookie;
 		else
 			*desc->dir_cookie = array->last_cookie;
+		if (nfs_readdir_use_cookie(file))
+			desc->ctx->pos = *desc->dir_cookie;
+		else
+			desc->ctx->pos++;
 		if (ctx->duped != 0)
 			ctx->duped = 1;
 	}
@@ -860,9 +887,14 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
 {
 	struct dentry	*dentry = file_dentry(file);
 	struct inode	*inode = d_inode(dentry);
-	nfs_readdir_descriptor_t my_desc,
-			*desc = &my_desc;
 	struct nfs_open_dir_context *dir_ctx = file->private_data;
+	nfs_readdir_descriptor_t my_desc = {
+		.file = file,
+		.ctx = ctx,
+		.dir_cookie = &dir_ctx->dir_cookie,
+		.plus = nfs_use_readdirplus(inode, ctx),
+	},
+			*desc = &my_desc;
 	int res = 0;
 
 	dfprintk(FILE, "NFS: readdir(%pD2) starting at cookie %llu\n",
@@ -875,14 +907,6 @@ static int nfs_readdir(struct file *file, struct dir_context *ctx)
 	 * to either find the entry with the appropriate number or
 	 * revalidate the cookie.
 	 */
-	memset(desc, 0, sizeof(*desc));
-
-	desc->file = file;
-	desc->ctx = ctx;
-	desc->dir_cookie = &dir_ctx->dir_cookie;
-	desc->decode = NFS_PROTO(inode)->decode_dirent;
-	desc->plus = nfs_use_readdirplus(inode, ctx);
-
 	if (ctx->pos == 0 || nfs_attribute_cache_expired(inode))
 		res = nfs_revalidate_mapping(inode, file->f_mapping);
 	if (res < 0)
@@ -954,7 +978,10 @@ static loff_t nfs_llseek_dir(struct file *filp, loff_t offset, int whence)
 	}
 	if (offset != filp->f_pos) {
 		filp->f_pos = offset;
-		dir_ctx->dir_cookie = 0;
+		if (nfs_readdir_use_cookie(filp))
+			dir_ctx->dir_cookie = offset;
+		else
+			dir_ctx->dir_cookie = 0;
 		dir_ctx->duped = 0;
 	}
 	inode_unlock(inode);
@@ -2282,7 +2309,7 @@ static DEFINE_SPINLOCK(nfs_access_lru_lock);
 static LIST_HEAD(nfs_access_lru_list);
 static atomic_long_t nfs_access_nr_entries;
 
-static unsigned long nfs_access_max_cachesize = ULONG_MAX;
+static unsigned long nfs_access_max_cachesize = 4*1024*1024;
 module_param(nfs_access_max_cachesize, ulong, 0644);
 MODULE_PARM_DESC(nfs_access_max_cachesize, "NFS access maximum total cache length");
 
@@ -2642,9 +2669,10 @@ static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask)
 	status = NFS_PROTO(inode)->access(inode, &cache);
 	if (status != 0) {
 		if (status == -ESTALE) {
-			nfs_zap_caches(inode);
 			if (!S_ISDIR(inode->i_mode))
-				set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
+				nfs_set_inode_stale(inode);
+			else
+				nfs_zap_caches(inode);
 		}
 		goto out;
 	}
@@ -2732,14 +2760,7 @@ force_lookup:
 	if (!NFS_PROTO(inode)->access)
 		goto out_notsup;
 
-	/* Always try fast lookups first */
-	rcu_read_lock();
-	res = nfs_do_access(inode, cred, mask|MAY_NOT_BLOCK);
-	rcu_read_unlock();
-	if (res == -ECHILD && !(mask & MAY_NOT_BLOCK)) {
-		/* Fast lookup failed, try the slow way */
-		res = nfs_do_access(inode, cred, mask);
-	}
+	res = nfs_do_access(inode, cred, mask);
 out:
 	if (!res && (mask & MAY_EXEC))
 		res = nfs_execute_ok(inode, mask);