> -----Original Message----- > From: Vitaly Kuznetsov [mailto:vkuznets@xxxxxxxxxx] > Sent: Monday, November 10, 2014 8:37 AM > To: KY Srinivasan; Haiyang Zhang; Greg Kroah-Hartman > Cc: devel@xxxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Dexuan Cui > Subject: [PATCH v2 1/2] Tools: hv: vssdaemon: report freeze errors > > When ioctl(fd, FIFREEZE, 0) results in an error we cannot report it to syslog > instantly since that can cause write to a frozen disk. > However, the name of the filesystem which caused the error and errno are > valuable and we would like to get a nice human-readable message in the log. > Save errno before calling vss_operate(VSS_OP_THAW) and report the error > right after. > > Unfortunately, FITHAW errors cannot be reported the same way as we need > to finish thawing all filesystems before calling syslog(). > > We should also avoid calling endmntent() for the second time in case we > encountered an error during freezing of '/' as it usually results in SEGSEGV. > > Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> > --- > tools/hv/hv_vss_daemon.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > diff --git a/tools/hv/hv_vss_daemon.c b/tools/hv/hv_vss_daemon.c index > b720d8f..ee44f0d 100644 > --- a/tools/hv/hv_vss_daemon.c > +++ b/tools/hv/hv_vss_daemon.c > @@ -82,7 +82,7 @@ static int vss_operate(int operation) > FILE *mounts; > struct mntent *ent; > unsigned int cmd; > - int error = 0, root_seen = 0; > + int error = 0, root_seen = 0, save_errno = 0; > > switch (operation) { > case VSS_OP_FREEZE: > @@ -114,7 +114,6 @@ static int vss_operate(int operation) > if (error && operation == VSS_OP_FREEZE) > goto err; > } > - endmntent(mounts); > > if (root_seen) { > error |= vss_do_freeze("/", cmd); > @@ -122,10 +121,19 @@ static int vss_operate(int operation) > goto err; > } > > - return error; > + goto out; > err: > - endmntent(mounts); > + save_errno = errno; > vss_operate(VSS_OP_THAW); > + /* Call syslog after we thaw all filesystems */ > + if (ent) > + syslog(LOG_ERR, "FREEZE of %s failed; error:%d %s", > + ent->mnt_dir, save_errno, strerror(save_errno)); > + else > + syslog(LOG_ERR, "FREEZE of / failed; error:%d %s", > save_errno, > + strerror(save_errno)); > +out: > + endmntent(mounts); > return error; > } > > -- > 1.9.3 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
