Merge tag '9p-for-4.20' of git://github.com/martinetd/linux

Pull 9p updates from Dominique Martinet:
 "Highlights this time around are the end of Matthew's work to remove
  the custom 9p request cache and use a slab directly for requests, with
  some extra patches on my end to not degrade performance, but it's a
  very good cleanup.

  Tomas and I fixed a few more syzkaller bugs (refcount is the big one),
  and I had a go at the coverity bugs and at some of the bugzilla
  reports we had open for a while.

  I'm a bit disappointed that I couldn't get much reviews for a few of
  my own patches, but the big ones got some and it's all been soaking in
  linux-next for quite a while so I think it should be OK.

  Summary:

   - Finish removing the custom 9p request cache mechanism

   - Embed part of the fcall in the request to have better slab
     performance (msize usually is power of two aligned)

   - syzkaller fixes:
      * add a refcount to 9p requests to avoid use after free
      * a few double free issues

   - A few coverity fixes

   - Some old patches that were in the bugzilla:
      * do not trust pdu content for size header
      * mount option for lock retry interval"

* tag '9p-for-4.20' of git://github.com/martinetd/linux: (21 commits)
  9p/trans_fd: put worker reqs on destroy
  9p/trans_fd: abort p9_read_work if req status changed
  9p: potential NULL dereference
  9p locks: fix glock.client_id leak in do_lock
  9p: p9dirent_read: check network-provided name length
  9p/rdma: remove useless check in cm_event_handler
  9p: acl: fix uninitialized iattr access
  9p locks: add mount option for lock retry interval
  9p: do not trust pdu content for stat item size
  9p: Rename req to rreq in trans_fd
  9p: fix spelling mistake in fall-through annotation
  9p/rdma: do not disconnect on down_interruptible EAGAIN
  9p: Add refcount to p9_req_t
  9p: rename p9_free_req() function
  9p: add a per-client fcall kmem_cache
  9p: embed fcall in req to round down buffer allocs
  9p: Remove p9_idpool
  9p: Use a slab for allocating requests
  9p: clear dangling pointers in p9stat_free
  v9fs_dir_readdir: fix double-free on p9stat_read error
  ...

1 files changed, 3 insertions, 16 deletions

diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c
index b0405d6aac85..cb6c4031af55 100644
--- a/fs/9p/vfs_dir.c
+++ b/fs/9p/vfs_dir.c
@@ -76,15 +76,6 @@ static inline int dt_type(struct p9_wstat *mistat)
 	return rettype;
 }
 
-static void p9stat_init(struct p9_wstat *stbuf)
-{
-	stbuf->name  = NULL;
-	stbuf->uid   = NULL;
-	stbuf->gid   = NULL;
-	stbuf->muid  = NULL;
-	stbuf->extension = NULL;
-}
-
 /**
  * v9fs_alloc_rdir_buf - Allocate buffer used for read and readdir
  * @filp: opened file structure
@@ -114,7 +105,6 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
 	int err = 0;
 	struct p9_fid *fid;
 	int buflen;
-	int reclen = 0;
 	struct p9_rdir *rdir;
 	struct kvec kvec;
 
@@ -145,15 +135,12 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
 			rdir->tail = n;
 		}
 		while (rdir->head < rdir->tail) {
-			p9stat_init(&st);
 			err = p9stat_read(fid->clnt, rdir->buf + rdir->head,
 					  rdir->tail - rdir->head, &st);
-			if (err) {
+			if (err <= 0) {
 				p9_debug(P9_DEBUG_VFS, "returned %d\n", err);
-				p9stat_free(&st);
 				return -EIO;
 			}
-			reclen = st.size+2;
 
 			over = !dir_emit(ctx, st.name, strlen(st.name),
 					 v9fs_qid2ino(&st.qid), dt_type(&st));
@@ -161,8 +148,8 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx)
 			if (over)
 				return 0;
 
-			rdir->head += reclen;
-			ctx->pos += reclen;
+			rdir->head += err;
+			ctx->pos += err;
 		}
 	}
 }