Merge tag 'vfs-6.14-final.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fixes from Christian Brauner:
 "A final set of fixes for this cycle:

  VFS:

   - Ensure that the stable offset api doesn't return duplicate
     directory entries when userspace has to perform the getdents call
     multiple times on large directories

  afs:

   - Prevent invalid pointer dereference during get_link RCU pathwalk

  fuse:

   - Fix deadlock caused by uninitialized rings when using io_uring with
     fuse

   - Handle race condition when using io_uring with fuse to prevent NULL
     dereference

  libnetfs:

   - Ensure that invalidate_cache is only called if implemented

   - Fix collection of results during pause when collection is
     offloaded

   - Ensure rolling_buffer_load_from_ra() doesn't clear mark bits

   - Make netfs_unbuffered_read() return ssize_t rather than int"

* tag 'vfs-6.14-final.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  libfs: Fix duplicate directory entry in offset_dir_lookup
  fuse: fix possible deadlock if rings are never initialized
  netfs: Fix netfs_unbuffered_read() to return ssize_t rather than int
  netfs: Fix rolling_buffer_load_from_ra() to not clear mark bits
  netfs: Call `invalidate_cache` only if implemented
  netfs: Fix collection of results during pause when collection offloaded
  fuse: fix uring race condition for null dereference of fc
  afs: Fix afs_atcell_get_link() to check if ws_cell is unset first

8 files changed, 22 insertions, 23 deletions

diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c
index 008698d706ca..7d997f7a8028 100644
--- a/fs/afs/dynroot.c
+++ b/fs/afs/dynroot.c
@@ -314,6 +314,9 @@ static const char *afs_atcell_get_link(struct dentry *dentry, struct inode *inod
 	const char *name;
 	bool dotted = vnode->fid.vnode == 3;
 
+	if (!rcu_access_pointer(net->ws_cell))
+		return ERR_PTR(-ENOENT);
+
 	if (!dentry) {
 		/* We're in RCU-pathwalk. */
 		cell = rcu_dereference(net->ws_cell);
@@ -325,9 +328,6 @@ static const char *afs_atcell_get_link(struct dentry *dentry, struct inode *inod
 		return name;
 	}
 
-	if (!rcu_access_pointer(net->ws_cell))
-		return ERR_PTR(-ENOENT);
-
 	down_read(&net->cells_lock);
 
 	cell = rcu_dereference_protected(net->ws_cell, lockdep_is_held(&net->cells_lock));
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 2c3a4d09e500..51e31df4c546 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -77,7 +77,7 @@ void fuse_set_initialized(struct fuse_conn *fc)
 static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
 {
 	return !fc->initialized || (for_background && fc->blocked) ||
-	       (fc->io_uring && !fuse_uring_ready(fc));
+	       (fc->io_uring && fc->connected && !fuse_uring_ready(fc));
 }
 
 static void fuse_drop_waiting(struct fuse_conn *fc)
diff --git a/fs/fuse/dev_uring.c b/fs/fuse/dev_uring.c
index ebd2931b4f2a..82bf458fa9db 100644
--- a/fs/fuse/dev_uring.c
+++ b/fs/fuse/dev_uring.c
@@ -208,11 +208,11 @@ static struct fuse_ring *fuse_uring_create(struct fuse_conn *fc)
 
 	init_waitqueue_head(&ring->stop_waitq);
 
-	fc->ring = ring;
 	ring->nr_queues = nr_queues;
 	ring->fc = fc;
 	ring->max_payload_sz = max_payload_size;
 	atomic_set(&ring->queue_refs, 0);
+	smp_store_release(&fc->ring, ring);
 
 	spin_unlock(&fc->lock);
 	return ring;
@@ -1041,7 +1041,7 @@ static int fuse_uring_register(struct io_uring_cmd *cmd,
 			       unsigned int issue_flags, struct fuse_conn *fc)
 {
 	const struct fuse_uring_cmd_req *cmd_req = io_uring_sqe_cmd(cmd->sqe);
-	struct fuse_ring *ring = fc->ring;
+	struct fuse_ring *ring = smp_load_acquire(&fc->ring);
 	struct fuse_ring_queue *queue;
 	struct fuse_ring_ent *ent;
 	int err;
diff --git a/fs/libfs.c b/fs/libfs.c
index 8444f5cc4064..dc042a975a56 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -496,7 +496,7 @@ offset_dir_lookup(struct dentry *parent, loff_t offset)
 		found = find_positive_dentry(parent, NULL, false);
 	else {
 		rcu_read_lock();
-		child = mas_find(&mas, DIR_OFFSET_MAX);
+		child = mas_find_rev(&mas, DIR_OFFSET_MIN);
 		found = find_positive_dentry(parent, child, false);
 		rcu_read_unlock();
 	}
diff --git a/fs/netfs/direct_read.c b/fs/netfs/direct_read.c
index 0bf3c2f5a710..5e3f0aeb51f3 100644
--- a/fs/netfs/direct_read.c
+++ b/fs/netfs/direct_read.c
@@ -125,9 +125,9 @@ static int netfs_dispatch_unbuffered_reads(struct netfs_io_request *rreq)
  * Perform a read to an application buffer, bypassing the pagecache and the
  * local disk cache.
  */
-static int netfs_unbuffered_read(struct netfs_io_request *rreq, bool sync)
+static ssize_t netfs_unbuffered_read(struct netfs_io_request *rreq, bool sync)
 {
-	int ret;
+	ssize_t ret;
 
 	_enter("R=%x %llx-%llx",
 	       rreq->debug_id, rreq->start, rreq->start + rreq->len - 1);
@@ -155,7 +155,7 @@ static int netfs_unbuffered_read(struct netfs_io_request *rreq, bool sync)
 	else
 		ret = -EIOCBQUEUED;
 out:
-	_leave(" = %d", ret);
+	_leave(" = %zd", ret);
 	return ret;
 }
 
diff --git a/fs/netfs/read_collect.c b/fs/netfs/read_collect.c
index 636cc5a98ef5..23c75755ad4e 100644
--- a/fs/netfs/read_collect.c
+++ b/fs/netfs/read_collect.c
@@ -682,14 +682,16 @@ void netfs_wait_for_pause(struct netfs_io_request *rreq)
 		trace_netfs_rreq(rreq, netfs_rreq_trace_wait_queue);
 		prepare_to_wait(&rreq->waitq, &myself, TASK_UNINTERRUPTIBLE);
 
-		subreq = list_first_entry_or_null(&stream->subrequests,
-						  struct netfs_io_subrequest, rreq_link);
-		if (subreq &&
-		    (!test_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags) ||
-		     test_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags))) {
-			__set_current_state(TASK_RUNNING);
-			netfs_read_collection(rreq);
-			continue;
+		if (!test_bit(NETFS_RREQ_OFFLOAD_COLLECTION, &rreq->flags)) {
+			subreq = list_first_entry_or_null(&stream->subrequests,
+							  struct netfs_io_subrequest, rreq_link);
+			if (subreq &&
+			    (!test_bit(NETFS_SREQ_IN_PROGRESS, &subreq->flags) ||
+			     test_bit(NETFS_SREQ_MADE_PROGRESS, &subreq->flags))) {
+				__set_current_state(TASK_RUNNING);
+				netfs_read_collection(rreq);
+				continue;
+			}
 		}
 
 		if (!test_bit(NETFS_RREQ_IN_PROGRESS, &rreq->flags) ||
diff --git a/fs/netfs/rolling_buffer.c b/fs/netfs/rolling_buffer.c
index 75d97af14b4a..207b6a326651 100644
--- a/fs/netfs/rolling_buffer.c
+++ b/fs/netfs/rolling_buffer.c
@@ -146,10 +146,6 @@ ssize_t rolling_buffer_load_from_ra(struct rolling_buffer *roll,
 
 	/* Store the counter after setting the slot. */
 	smp_store_release(&roll->next_head_slot, to);
-
-	for (; ix < folioq_nr_slots(fq); ix++)
-		folioq_clear(fq, ix);
-
 	return size;
 }
 
diff --git a/fs/netfs/write_collect.c b/fs/netfs/write_collect.c
index 294f67795f79..3fca59e6475d 100644
--- a/fs/netfs/write_collect.c
+++ b/fs/netfs/write_collect.c
@@ -400,7 +400,8 @@ void netfs_write_collection_worker(struct work_struct *work)
 	trace_netfs_rreq(wreq, netfs_rreq_trace_write_done);
 
 	if (wreq->io_streams[1].active &&
-	    wreq->io_streams[1].failed) {
+	    wreq->io_streams[1].failed &&
+	    ictx->ops->invalidate_cache) {
 		/* Cache write failure doesn't prevent writeback completion
 		 * unless we're in disconnected mode.
 		 */