[PATCH 09/10] libfrog: improve ramdisk handling in platform_flush_device

[Christoph Hellwig <hch@lst.de>]

The ramdisk driver was quirky for BLKFLSBUF, but there never was
any reason to skip the fsync.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 copy/xfs_copy.c    |  2 +-
 libfrog/linux.c    | 13 ++++++-------
 libfrog/platform.h |  2 +-
 libxfs/init.c      |  2 +-
 libxfs/rdwr.c      |  6 ++++--
 5 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/copy/xfs_copy.c b/copy/xfs_copy.c
index 5435c87dba38..4692a4ffb961 100644
--- a/copy/xfs_copy.c
+++ b/copy/xfs_copy.c
@@ -141,7 +141,7 @@ check_errors(void)
 
 	for (i = 0; i < num_targets; i++)  {
 		if (target[i].state != INACTIVE) {
-			if (platform_flush_device(target[i].fd, 0)) {
+			if (platform_flush_device(target[i].fd)) {
 				target[i].error = errno;
 				target[i].state = INACTIVE;
 				target[i].err_type = 2;
diff --git a/libfrog/linux.c b/libfrog/linux.c
index 46a5ff39e2eb..5c0d3ed7e935 100644
--- a/libfrog/linux.c
+++ b/libfrog/linux.c
@@ -152,15 +152,11 @@ platform_set_blocksize(int fd, char *path, dev_t device, int blocksize,
  */
 int
 platform_flush_device(
-	int		fd,
-	dev_t		device)
+	int		fd)
 {
 	struct stat	st;
 	int		ret;
 
-	if (major(device) == RAMDISK_MAJOR)
-		return 0;
-
 	ret = fsync(fd);
 	if (ret)
 		return ret;
@@ -169,9 +165,12 @@ platform_flush_device(
 	if (ret)
 		return ret;
 
-	if (S_ISBLK(st.st_mode))
+	/*
+	 * Historically the ram disk driver destroyed all data when BLKFLSBUF
+	 * was called.  That has been fixed a long time, but still be careful.
+	 */
+	if (S_ISBLK(st.st_mode) && major(st.st_rdev) != RAMDISK_MAJOR)
 		return ioctl(fd, BLKFLSBUF, 0);
-
 	return 0;
 }
 
diff --git a/libfrog/platform.h b/libfrog/platform.h
index 20f9bdf5ce5b..39d558f08629 100644
--- a/libfrog/platform.h
+++ b/libfrog/platform.h
@@ -12,7 +12,7 @@ int platform_check_ismounted(char *path, char *block, struct stat *sptr,
 int platform_check_iswritable(char *path, char *block, struct stat *sptr);
 void platform_set_blocksize(int fd, char *path, dev_t device, int bsz,
 		bool fatal);
-int platform_flush_device(int fd, dev_t device);
+int platform_flush_device(int fd);
 int platform_direct_blockdev(void);
 int platform_align_blockdev(void);
 unsigned long platform_physmem(void);	/* in kilobytes */
diff --git a/libxfs/init.c b/libxfs/init.c
index 5a4b255165ab..4c71027d2805 100644
--- a/libxfs/init.c
+++ b/libxfs/init.c
@@ -172,7 +172,7 @@ libxfs_device_close(
 {
 	int			ret;
 
-	ret = platform_flush_device(dev->fd, dev->dev);
+	ret = platform_flush_device(dev->fd);
 	if (ret) {
 		ret = -errno;
 		fprintf(stderr,
diff --git a/libxfs/rdwr.c b/libxfs/rdwr.c
index 837288be0307..33a0d144a1aa 100644
--- a/libxfs/rdwr.c
+++ b/libxfs/rdwr.c
@@ -1112,8 +1112,10 @@ libxfs_blkdev_issue_flush(
 	if (btp->bt_dev == 0)
 		return 0;
 
-	ret = platform_flush_device(btp->bt_fd, btp->bt_dev);
-	return ret ? -errno : 0;
+	ret = platform_flush_device(btp->bt_fd);
+	if (ret)
+		return -errno;
+	return 0;
 }
 
 /*
-- 
2.53.0