All of lore.kernel.org
 help / color / mirror / Atom feed
* [U-Boot] [PATCH] fix: fw_env: Prevent writing error message on special files, which don't support fsync
@ 2017-08-27 11:46 Lukasz Majewski
  2017-08-27 18:34 ` Michael Heimpold
  2017-09-04  0:42 ` [U-Boot] " Tom Rini
  0 siblings, 2 replies; 5+ messages in thread
From: Lukasz Majewski @ 2017-08-27 11:46 UTC (permalink / raw)
  To: u-boot

According to fsync specification [1] some special files (e.g., a pipe, FIFO,
or socket) don't support synchronization and return either EROFS or EINVAL.

On the linux side the sys_fsync -> do_fsync() checks if the requested file
has f_op->fsync defined. If not it returns EINVAL [2].

This commit prevents writing error messages for files (devices), which
do not support fsync().

[1] - http://man7.org/linux/man-pages/man2/fsync.2.html
[2] - http://elixir.free-electrons.com/linux/v4.13-rc6/source/fs/sync.c#L183

Signed-off-by: Lukasz Majewski <lukma@denx.de>
---
 tools/env/fw_env.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c
index c9c79e0..ab7d85b 100644
--- a/tools/env/fw_env.c
+++ b/tools/env/fw_env.c
@@ -1088,14 +1088,16 @@ static int flash_io (int mode)
 
 		rc = flash_write (fd_current, fd_target, dev_target);
 
-		if (fsync (fd_current)) {
+		if (fsync(fd_current) &&
+		    !(errno == EINVAL || errno == EROFS)) {
 			fprintf (stderr,
 				 "fsync failed on %s: %s\n",
 				 DEVNAME (dev_current), strerror (errno));
 		}
 
 		if (HaveRedundEnv) {
-			if (fsync (fd_target)) {
+			if (fsync(fd_target) &&
+			    !(errno == EINVAL || errno == EROFS)) {
 				fprintf (stderr,
 					 "fsync failed on %s: %s\n",
 					 DEVNAME (dev_current), strerror (errno));
-- 
2.1.4

^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2017-09-04  0:42 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-08-27 11:46 [U-Boot] [PATCH] fix: fw_env: Prevent writing error message on special files, which don't support fsync Lukasz Majewski
2017-08-27 18:34 ` Michael Heimpold
2017-08-27 19:20   ` Łukasz Majewski
2017-08-27 20:01     ` Tom Rini
2017-09-04  0:42 ` [U-Boot] " Tom Rini

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.