diff options
Diffstat (limited to '')
| -rw-r--r-- | g13/backend.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/g13/backend.c b/g13/backend.c index 52e1e0a34..b35887be3 100644 --- a/g13/backend.c +++ b/g13/backend.c @@ -23,6 +23,7 @@ #include <string.h> #include <errno.h> #include <unistd.h> +#include <sys/stat.h> #include "g13.h" #include "i18n.h" @@ -88,6 +89,64 @@ be_is_supported_conttype (int conttype) } +/* Create a lock file for the container FNAME and store the lock at + * R_LOCK and return 0. On error return an error code and store NULL + * at R_LOCK. */ +gpg_error_t +be_take_lock_for_create (ctrl_t ctrl, const char *fname, dotlock_t *r_lock) +{ + gpg_error_t err; + dotlock_t lock = NULL; + struct stat sb; + + *r_lock = NULL; + + /* A DM-crypt container requires special treatment by using the + syshelper fucntions. */ + if (ctrl->conttype == CONTTYPE_DM_CRYPT) + { + /* */ + err = gpg_error (GPG_ERR_NOT_IMPLEMENTED); + goto leave; + } + + + /* A quick check to see that no container with that name already + exists. */ + if (!access (fname, F_OK)) + { + err = gpg_error (GPG_ERR_EEXIST); + goto leave; + } + + /* Take a lock and proceed with the creation. If there is a lock we + immediately return an error because for creation it does not make + sense to wait. */ + lock = dotlock_create (fname, 0); + if (!lock) + { + err = gpg_error_from_syserror (); + goto leave; + } + if (dotlock_take (lock, 0)) + { + err = gpg_error_from_syserror (); + goto leave; + } + + /* Check again that the file does not exist. */ + err = stat (fname, &sb)? 0 : gpg_error (GPG_ERR_EEXIST); + + leave: + if (!err) + { + *r_lock = lock; + lock = NULL; + } + dotlock_destroy (lock); + return err; +} + /* If the backend requires a separate file or directory for the container, return its name by computing it from FNAME which gives |