On 03/07/2012 03:36 PM, J. Bruce Fields wrote:
> On Wed, Mar 07, 2012 at 02:56:30PM -0500, Steve Dickson wrote:
>> This problem can occur when multiple cluster services fail over
>> at the same time, causing missing high-available exports.
>> Having a lot of nfs-exports will trigger this issue easier.
>
> Isn't the locking in support/export/xtab.c supposed to take care of
> this?
>
> I may be confused--I forget what all these files are for....
hmm... your right... those do take out flock()s during I/O..
There must be a hole somewhere they can get corrupted...
steved.
>
> --b.
>
>>
>> Signed-off-by: Steve Dickson <steved@xxxxxxxxxx>
>> ---
>> support/include/exportfs.h | 4 ++++
>> utils/exportfs/exportfs.c | 24 ++++++++++++++++++++++++
>> 2 files changed, 28 insertions(+), 0 deletions(-)
>>
>> diff --git a/support/include/exportfs.h b/support/include/exportfs.h
>> index 01e87dd..99916e5 100644
>> --- a/support/include/exportfs.h
>> +++ b/support/include/exportfs.h
>> @@ -32,6 +32,10 @@ enum {
>> FSLOC_STUB
>> };
>>
>> +#ifndef EXP_LOCKFILE
>> +#define EXP_LOCKFILE "/var/lib/nfs/export-lock"
>> +#endif
>> +
>> typedef struct mclient {
>> struct mclient * m_next;
>> char * m_hostname;
>> diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
>> index 7432a65..769d438 100644
>> --- a/utils/exportfs/exportfs.c
>> +++ b/utils/exportfs/exportfs.c
>> @@ -16,6 +16,7 @@
>> #include <sys/stat.h>
>> #include <sys/vfs.h>
>> #include <sys/stat.h>
>> +#include <sys/file.h>
>> #include <unistd.h>
>> #include <stdbool.h>
>> #include <stdlib.h>
>> @@ -44,6 +45,23 @@ static void validate_export(nfs_export *exp);
>> static int matchhostname(const char *hostname1, const char *hostname2);
>> static void export_d_read(const char *dname);
>>
>> +static const char *lockfile = EXP_LOCKFILE;
>> +static int _lockfd = -1;
>> +
>> +void
>> +grab_lockfile()
>> +{
>> + _lockfd = open(lockfile, O_CREAT|O_RDWR, 0666);
>> + if (_lockfd != -1)
>> + lockf(_lockfd, F_LOCK, 0);
>> +}
>> +void
>> +release_lockfile()
>> +{
>> + if (_lockfd != -1)
>> + lockf(_lockfd, F_ULOCK, 0);
>> +}
>> +
>> int
>> main(int argc, char **argv)
>> {
>> @@ -129,6 +147,12 @@ main(int argc, char **argv)
>> return 0;
>> }
>> }
>> + /*
>> + * Serialize things as best we can
>> + */
>> + grab_lockfile();
>> + atexit(release_lockfile);
>> +
>> if (f_export && ! f_ignore) {
>> export_read(_PATH_EXPORTS);
>> export_d_read(_PATH_EXPORTS_D);
>> --
>> 1.7.7.6
>>
>> --
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