svn commit: r345582 - projects/fuse2/sys/fs/fuse

[Alan Somers]

Author: asomers
Date: Wed Mar 27 16:45:30 2019
New Revision: 345582
URL: https://svnweb.freebsd.org/changeset/base/345582

Log:
  fusefs: don't ignore errors in fuse_vnode_refreshsize
  
  Reported by:	Coverity
  Coverity CID:	1368622
  Sponsored by:	The FreeBSD Foundation

Modified:
  projects/fuse2/sys/fs/fuse/fuse_node.c
  projects/fuse2/sys/fs/fuse/fuse_node.h
  projects/fuse2/sys/fs/fuse/fuse_vnops.c

Modified: projects/fuse2/sys/fs/fuse/fuse_node.c
==============================================================================
--- projects/fuse2/sys/fs/fuse/fuse_node.c	Wed Mar 27 16:26:03 2019	(r345581)
+++ projects/fuse2/sys/fs/fuse/fuse_node.c	Wed Mar 27 16:45:30 2019	(r345582)
@@ -392,20 +392,22 @@ fuse_vnode_savesize(struct vnode *vp, struct ucred *cr
 	return err;
 }
 
-void
+int
 fuse_vnode_refreshsize(struct vnode *vp, struct ucred *cred)
 {
 
 	struct fuse_vnode_data *fvdat = VTOFUD(vp);
 	struct vattr va;
+	int err;
 
 	if ((fvdat->flag & FN_SIZECHANGE) != 0 ||
 	    fuse_data_cache_mode == FUSE_CACHE_UC ||
 	    (fuse_refresh_size == 0 && fvdat->filesize != 0))
-		return;
+		return 0;
 
-	VOP_GETATTR(vp, &va, cred);
+	err = VOP_GETATTR(vp, &va, cred);
 	SDT_PROBE2(fuse, , node, trace, 1, "refreshed file size");
+	return err;
 }
 
 int

Modified: projects/fuse2/sys/fs/fuse/fuse_node.h
==============================================================================
--- projects/fuse2/sys/fs/fuse/fuse_node.h	Wed Mar 27 16:26:03 2019	(r345581)
+++ projects/fuse2/sys/fs/fuse/fuse_node.h	Wed Mar 27 16:45:30 2019	(r345582)
@@ -123,7 +123,7 @@ int fuse_vnode_get(struct mount *mp, struct fuse_entry
 void fuse_vnode_open(struct vnode *vp, int32_t fuse_open_flags,
     struct thread *td);
 
-void fuse_vnode_refreshsize(struct vnode *vp, struct ucred *cred);
+int fuse_vnode_refreshsize(struct vnode *vp, struct ucred *cred);
 
 int fuse_vnode_savesize(struct vnode *vp, struct ucred *cred);
 

Modified: projects/fuse2/sys/fs/fuse/fuse_vnops.c
==============================================================================
--- projects/fuse2/sys/fs/fuse/fuse_vnops.c	Wed Mar 27 16:26:03 2019	(r345581)
+++ projects/fuse2/sys/fs/fuse/fuse_vnops.c	Wed Mar 27 16:45:30 2019	(r345582)
@@ -1712,20 +1712,23 @@ fuse_vnop_strategy(struct vop_strategy_args *ap)
 		bufdone(bp);
 		return ENXIO;
 	}
-	if (bp->b_iocmd == BIO_WRITE)
-		fuse_vnode_refreshsize(vp, NOCRED);
+	if (bp->b_iocmd == BIO_WRITE) {
+		int err;
 
-	(void)fuse_io_strategy(vp, bp);
+		err = fuse_vnode_refreshsize(vp, NOCRED);
+		if (err) {
+			bp->b_ioflags |= BIO_ERROR;
+			bp->b_error = err;
+			return 0;
+		}
+	}
 
 	/*
-	 * This is a dangerous function. If returns error, that might mean a
-	 * panic. We prefer pretty much anything over being forced to panic
-	 * by a malicious daemon (a demon?). So we just return 0 anyway. You
-	 * should never mind this: this function has its own error
-	 * propagation mechanism via the argument buffer, so
-	 * not-that-melodramatic residents of the call chain still will be
-	 * able to know what to do.
+	 * VOP_STRATEGY always returns zero and signals error via bp->b_ioflags.
+	 * fuse_io_strategy sets bp's error fields
 	 */
+	(void)fuse_io_strategy(vp, bp);
+
 	return 0;
 }
 
@@ -1791,11 +1794,14 @@ fuse_vnop_write(struct vop_write_args *ap)
 	struct uio *uio = ap->a_uio;
 	int ioflag = ap->a_ioflag;
 	struct ucred *cred = ap->a_cred;
+	int err;
 
 	if (fuse_isdeadfs(vp)) {
 		return ENXIO;
 	}
-	fuse_vnode_refreshsize(vp, cred);
+	err = fuse_vnode_refreshsize(vp, cred);
+	if (err)
+		return err;
 
 	if (VTOFUD(vp)->flag & FN_DIRECTIO) {
 		ioflag |= IO_DIRECT;