createFile(bpContext *ctx, struct restore_pkt *rp)
Called for a command plugin to create a file during a Restore job before restoring the data. This entry point is called before any I/O is done on the file. After this call, Bacula will call pluginIO() to open the file for write.
The data in the restore_pkt is passed to the plugin and is based on the data that was originally given by the plugin during the backup and the current user restore settings (e.g. where, RegexWhere, replace). This allows the plugin to first create a file (if necessary) so that the data can be transmitted to it. The next call to the plugin will be a pluginIO command with a request to open the file write-only.
This call must return one of the following values:
enum {
CF_SKIP = 1, /* skip file (not newer or something) */
CF_ERROR, /* error creating file */
CF_EXTRACT, /* file created, data to extract */
CF_CREATED, /* file created, no data to extract */
CF_CORE /* let bacula core handles the file creation */
};
in the restore_pkt value create_status. For a normal file, unless there is an error, you must return CF_EXTRACT.
struct restore_pkt {
int32_t pkt_size; /* size of this packet */
int32_t stream; /* attribute stream id */
int32_t data_stream; /* id of data stream to follow */
int32_t type; /* file type FT */
int32_t file_index; /* file index */
int32_t LinkFI; /* file index to data if hard link */
uid_t uid; /* userid */
struct stat statp; /* decoded stat packet */
const char *attrEx; /* extended attributes if any */
const char *ofname; /* output filename */
const char *olname; /* output link name */
const char *where; /* where */
const char *RegexWhere; /* regex where */
int replace; /* replace flag */
int create_status; /* status from createFile() */
int32_t pkt_end; /* end packet sentinel */
};
Typical code to create a regular file would be the following:
struct plugin_ctx *p_ctx = (struct plugin_ctx *)ctx->pContext;
time_t now = time(NULL);
sp->fname = p_ctx->fname; /* set the full path/filename I want to create */
sp->type = FT_REG;
sp->statp.st_mode = 0700 | S_IFREG;
sp->statp.st_ctime = now;
sp->statp.st_mtime = now;
sp->statp.st_atime = now;
sp->statp.st_size = -1;
sp->statp.st_blksize = 4096;
sp->statp.st_blocks = 1;
return bRC_OK;
This will create a virtual file. If you are creating a file that actually exists, you will most likely want to fill the statp packet using the stat() system call.
Creating a directory is similar, but requires a few extra steps:
struct plugin_ctx *p_ctx = (struct plugin_ctx *)ctx->pContext;
time_t now = time(NULL);
sp->fname = p_ctx->fname; /* set the full path I want to create */
sp->link = xxx; where xxx is p_ctx->fname with a trailing forward slash
sp->type = FT_DIREND
sp->statp.st_mode = 0700 | S_IFDIR;
sp->statp.st_ctime = now;
sp->statp.st_mtime = now;
sp->statp.st_atime = now;
sp->statp.st_size = -1;
sp->statp.st_blksize = 4096;
sp->statp.st_blocks = 1;
return bRC_OK;
The link field must be set with the full cononical path name, which always ends with a forward slash. If you do not terminate it with a forward slash, you will surely have problems later.
As with the example that creates a file, if you are backing up a real directory, you will want to do an stat() on the directory.
Note, if you want the directory permissions and times to be correctly restored, you must create the directory after all the file directories have been sent to Bacula. That allows the restore process to restore all the files in a directory using default directory options, then at the end, restore the directory permissions. If you do it the other way around, each time you restore a file, the OS will modify the time values for the directory entry.
Possible Next Steps
Go back to Plugin EntryPoints.
Go back to Bacula FD Plugin API.
Go back to Developer Guide.