Revert behavior of 59eab10 on not-Linux

It turns out that short-circuiting the EFAULT behavior on a short read breaks things on FreeBSD. So until there's a nicer solution, let's just revert the behavior for not-Linux. Reference: https://reviews.freebsd.org/R10:70f51f0e474ffe1fb74cb427423a2fba3637544d Reviewed-by: Brian Behlendorf <[email protected]> Reviewed-by: Tony Nguyen <[email protected]> Reviewed-by: Brian Atkinson <[email protected]> Signed-off-by: Rich Ercolani <[email protected]> Closes #12698
openzfs · Nov 4, 2021 · 0567946 · 0567946
1 parent e79b680
commit 0567946
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c
@@ -254,7 +254,9 @@ zfs_read(struct znode *zp, zfs_uio_t *uio, int ioflag, cred_t *cr)
 	}
 
 	ASSERT(zfs_uio_offset(uio) < zp->z_size);
+#if defined(__linux__)
 	ssize_t start_offset = zfs_uio_offset(uio);
+#endif
 	ssize_t n = MIN(zfs_uio_resid(uio), zp->z_size - zfs_uio_offset(uio));
 	ssize_t start_resid = n;
 
@@ -277,13 +279,18 @@ zfs_read(struct znode *zp, zfs_uio_t *uio, int ioflag, cred_t *cr)
 			/* convert checksum errors into IO errors */
 			if (error == ECKSUM)
 				error = SET_ERROR(EIO);
+
+#if defined(__linux__)
 			/*
 			 * if we actually read some bytes, bubbling EFAULT
-			 * up to become EAGAIN isn't what we want here.
+			 * up to become EAGAIN isn't what we want here...
+			 *
+			 * ...on Linux, at least. On FBSD, doing this breaks.
 			 */
 			if (error == EFAULT &&
 			    (zfs_uio_offset(uio) - start_offset) != 0)
 				error = 0;
+#endif
 			break;
 		}