[PATCH] bin/*: improve error message on failure of nilfs_open()

[Ryusuke Konishi]

The error message on failure of nilfs_open() function has two issues
in commands lscp, lssu, mkcp, chcp, rmcp, and dumpseg:

1) When device name is omitted, a null pointer is passed to a string
type field of the error message and a broken message is printed as
below:

lssu: (null): cannot open NILFS

2) Description of errno is not shown in the error message.

This fixes these issues.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke-***@public.gmane.org>
---
bin/chcp.c | 3 ++-
bin/dumpseg.c | 3 ++-
bin/lscp.c | 4 ++--
bin/lssu.c | 4 ++--
bin/mkcp.c | 3 ++-
bin/rmcp.c | 3 ++-
6 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/bin/chcp.c b/bin/chcp.c
index 837cf01..8596a14 100644
--- a/bin/chcp.c
+++ b/bin/chcp.c
@@ -139,7 +139,8 @@ int main(int argc, char *argv[])

nilfs = nilfs_open(dev, NULL, NILFS_OPEN_RDWR | NILFS_OPEN_GCLK);
if (nilfs == NULL) {
- fprintf(stderr, "%s: %s: cannot open NILFS\n", progname, dev);
+ fprintf(stderr, "%s: cannot open NILFS on %s: %m\n",
+ progname, dev ? : "device");
exit(1);
}

diff --git a/bin/dumpseg.c b/bin/dumpseg.c
index 24a3624..0c138b2 100644
--- a/bin/dumpseg.c
+++ b/bin/dumpseg.c
@@ -218,7 +218,8 @@ int main(int argc, char *argv[])

nilfs = nilfs_open(dev, NULL, NILFS_OPEN_RAW);
if (nilfs == NULL) {
- fprintf(stderr, "%s: %s: cannot open NILFS\n", progname, dev);
+ fprintf(stderr, "%s: cannot open NILFS on %s: %m\n",
+ progname, dev ? : "device");
exit(1);
}

diff --git a/bin/lscp.c b/bin/lscp.c
index 52447e5..2de81b6 100644
--- a/bin/lscp.c
+++ b/bin/lscp.c
@@ -401,8 +401,8 @@ int main(int argc, char *argv[])

nilfs = nilfs_open(dev, NULL, NILFS_OPEN_RDONLY);
if (nilfs == NULL) {
- fprintf(stderr, "%s: %s: cannot open NILFS\n",
- progname, dev);
+ fprintf(stderr, "%s: cannot open NILFS on %s: %m\n",
+ progname, dev ? : "device");
exit(EXIT_FAILURE);
}

diff --git a/bin/lssu.c b/bin/lssu.c
index ebbd926..09ed973 100644
--- a/bin/lssu.c
+++ b/bin/lssu.c
@@ -382,8 +382,8 @@ int main(int argc, char *argv[])

nilfs = nilfs_open(dev, NULL, open_flags);
if (nilfs == NULL) {
- fprintf(stderr, "%s: %s: cannot open NILFS\n",
- progname, dev);
+ fprintf(stderr, "%s: cannot open NILFS on %s: %m\n",
+ progname, dev ? : "device");
exit(1);
}

diff --git a/bin/mkcp.c b/bin/mkcp.c
index 57cf0c8..9dd6f0e 100644
--- a/bin/mkcp.c
+++ b/bin/mkcp.c
@@ -123,7 +123,8 @@ int main(int argc, char *argv[])

nilfs = nilfs_open(dev, NULL, NILFS_OPEN_RDWR | NILFS_OPEN_GCLK);
if (nilfs == NULL) {
- fprintf(stderr, "%s: %s: cannot open NILFS\n", progname, dev);
+ fprintf(stderr, "%s: cannot open NILFS on %s: %m\n",
+ progname, dev ? : "device");
exit(1);
}

diff --git a/bin/rmcp.c b/bin/rmcp.c
index 92d672f..0943fe0 100644
--- a/bin/rmcp.c
+++ b/bin/rmcp.c
@@ -193,7 +193,8 @@ int main(int argc, char *argv[])

nilfs = nilfs_open(dev, NULL, NILFS_OPEN_RDWR);
if (nilfs == NULL) {
- fprintf(stderr, "%s: %s: cannot open NILFS\n", progname, dev);
+ fprintf(stderr, "%s: cannot open NILFS on %s: %m\n",
+ progname, dev ? : "device");
exit(1);
}