xfsdump/xfsrestore: don't use O_DIRECT on the RT device

For undocumented reasons xfsdump and xfsrestore use O_DIRECT for RT
files  On a rt device with 4k sector size this runs into alignment
issues, e.g. xfs/060 fails with this message:

xfsrestore: attempt to write 237568 bytes to dumpdir/large000 at offset 54947844 failed: Invalid argument

Switch to using buffered I/O to match the main device and remove all
the code to align to the minimum direct I/O size and make these
alignment issues go away.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
diff --git a/doc/xfsdump.html b/doc/xfsdump.html
index efd3890..eec7dac 100644
--- a/doc/xfsdump.html
+++ b/doc/xfsdump.html
@@ -884,7 +884,6 @@
                    <ul>
                    <li> S_IFREG -> <b>restore_reg</b> - restore regular file
                       <ul>
-                      <li>if realtime set O_DIRECT
                       <li>truncate file to bs_size
                       <li>set the bs_xflags for extended attributes
                       <li>set DMAPI fields if necessary
diff --git a/dump/content.c b/dump/content.c
index 9117d39..6462267 100644
--- a/dump/content.c
+++ b/dump/content.c
@@ -4319,15 +4319,8 @@
 			   struct xfs_bstat *statp,
 			   extent_group_context_t *gcp)
 {
-	bool_t isrealtime;
-	int oflags;
 	struct flock fl;
 
-	isrealtime = (bool_t)(statp->bs_xflags & XFS_XFLAG_REALTIME);
-	oflags = O_RDONLY;
-	if (isrealtime) {
-		oflags |= O_DIRECT;
-	}
 	(void)memset((void *)gcp, 0, sizeof(*gcp));
 	gcp->eg_bmap[0].bmv_offset = 0;
 	gcp->eg_bmap[0].bmv_length = -1;
@@ -4336,7 +4329,7 @@
 	gcp->eg_endbmapp = &gcp->eg_bmap[1];
 	gcp->eg_bmapix = 0;
 	gcp->eg_gbmcnt = 0;
-	gcp->eg_fd = jdm_open(fshandlep, statp, oflags);
+	gcp->eg_fd = jdm_open(fshandlep, statp, O_RDONLY);
 	if (gcp->eg_fd < 0) {
 		return RV_ERROR;
 	}
@@ -4387,7 +4380,6 @@
 		   off64_t *bytecntp,
 		   bool_t *cmpltflgp)
 {
-	struct dioattr da;
 	drive_ops_t *dop = drivep->d_opsp;
 	bool_t isrealtime = (bool_t)(statp->bs_xflags
 					&
@@ -4397,18 +4389,6 @@
 	int rval;
 	rv_t rv;
 
-	/*
-	 * Setup realtime I/O size.
-	 */
-	if (isrealtime) {
-		if ((ioctl(gcp->eg_fd, XFS_IOC_DIOINFO, &da) < 0)) {
-			mlog(MLOG_NORMAL | MLOG_WARNING, _(
-			      "dioinfo failed ino %llu\n"),
-			      statp->bs_ino);
-			da.d_miniosz = PGSZ;
-		}
-	}
-
 	/* dump extents until the recommended extent length is achieved
 	 */
 	nextoffset = *nextoffsetp;
@@ -4677,17 +4657,13 @@
 		}
 		assert(extsz > 0);
 
-		/* if the resultant extent would put us over maxcnt,
-		 * shorten it, and round up to the next BBSIZE (round
-		 * upto d_miniosz for realtime).
+		/*
+		 * If the resultant extent would put us over maxcnt,
+		 * shorten it, and round up to the next BBSIZE.
 		 */
 		if (extsz > maxcnt - (bytecnt + sizeof(extenthdr_t))) {
-			int iosz;
+			int iosz = BBSIZE;
 
-			if (isrealtime)
-				iosz = da.d_miniosz;
-			else
-				iosz = BBSIZE;
 			extsz = maxcnt - (bytecnt + sizeof(extenthdr_t));
 			extsz = (extsz + (off64_t)(iosz - 1))
 				&
@@ -4723,18 +4699,14 @@
 			return RV_OK;
 		}
 
-		/* if the resultant extent extends beyond the end of the
+		/*
+		 * If the resultant extent extends beyond the end of the
 		 * file, shorten the extent to the nearest BBSIZE alignment
-		 * at or beyond EOF.  (Shorten to d_miniosz for realtime
-		 * files).
+		 * at or beyond EOF.
 		 */
 		if (extsz > statp->bs_size - offset) {
-			int iosz;
+			int iosz = BBSIZE;
 
-			if (isrealtime)
-				iosz = da.d_miniosz;
-			else
-				iosz = BBSIZE;
 			extsz = statp->bs_size - offset;
 			extsz = (extsz + (off64_t)(iosz - 1))
 				&
diff --git a/restore/content.c b/restore/content.c
index 488ae20..7ec3a4d 100644
--- a/restore/content.c
+++ b/restore/content.c
@@ -7435,7 +7435,6 @@
 	int rval;
 	struct fsxattr fsxattr;
 	struct stat64 stat;
-	int oflags;
 
 	if (!path)
 		return BOOL_TRUE;
@@ -7470,11 +7469,7 @@
 	if (tranp->t_toconlypr)
 		return BOOL_TRUE;
 
-	oflags = O_CREAT | O_RDWR;
-	if (persp->a.dstdirisxfspr && bstatp->bs_xflags & XFS_XFLAG_REALTIME)
-		oflags |= O_DIRECT;
-
-	*fdp = open(path, oflags, S_IRUSR | S_IWUSR);
+	*fdp = open(path, O_CREAT | O_RDWR, S_IRUSR | S_IWUSR);
 	if (*fdp < 0) {
 		mlog(MLOG_NORMAL | MLOG_WARNING,
 		      _("open of %s failed: %s: discarding ino %llu\n"),
@@ -8392,8 +8387,6 @@
 	off64_t off = ehdrp->eh_offset;
 	off64_t sz = ehdrp->eh_sz;
 	off64_t new_off;
-	struct dioattr da;
-	bool_t isrealtime = BOOL_FALSE;
 
 	*bytesreadp = 0;
 
@@ -8418,18 +8411,6 @@
 		}
 		assert(new_off == off);
 	}
-	if ((fd != -1) && (bstatp->bs_xflags & XFS_XFLAG_REALTIME)) {
-		if ((ioctl(fd, XFS_IOC_DIOINFO, &da) < 0)) {
-			mlog(MLOG_NORMAL | MLOG_WARNING, _(
-			      "dioinfo %s failed: "
-			      "%s: discarding ino %llu\n"),
-			      path,
-			      strerror(errno),
-			      fhdrp->fh_stat.bs_ino);
-			fd = -1;
-		} else
-			isrealtime = BOOL_TRUE;
-	}
 
 	/* move from media to fs.
 	 */
@@ -8520,26 +8501,6 @@
 						<=
 						(size_t)INTGENMAX);
 					/*
-					 * Realtime files must be written
-					 * to the end of the block even if
-					 * it has been truncated back.
-					 */
-					if (isrealtime &&
-					    (remaining % da.d_miniosz != 0 ||
-					     remaining < da.d_miniosz)) {
-						/*
-						 * Since the ring and static
-						 * buffers from the different
-						 * drives are always large, we
-						 * just need to write to the
-						 * end of the next block
-						 * boundry and truncate.
-						 */
-						rttrunc = remaining;
-						remaining += da.d_miniosz -
-						   (remaining % da.d_miniosz);
-					}
-					/*
 					 * Do the write. Due to delayed allocation
 					 * it's possible to receive false ENOSPC
 					 * errors when the filesystem is nearly