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btrfs-progs
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btrfs-progs/btrfs.c

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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "kerncompat.h"
#include "btrfs_cmds.h"
#include "version.h"
#define BASIC_HELP 0
#define ADVANCED_HELP 1
typedef int (*CommandFunction)(int argc, char **argv);
struct Command {
CommandFunction func; /* function which implements the command */
int nargs; /* if == 999, any number of arguments
if >= 0, number of arguments,
if < 0, _minimum_ number of arguments */
char *verb; /* verb */
char *help; /* help lines; from the 2nd line onward they
are automatically indented */
char *adv_help; /* advanced help message; from the 2nd line
onward they are automatically indented */
/* the following fields are run-time filled by the program */
char **cmds; /* array of subcommands */
int ncmds; /* number of subcommand */
};
static struct Command commands[] = {
/*
avoid short commands different for the case only
*/
{ do_clone, 2,
"subvolume snapshot", "[-r] <source> [<dest>/]<name>\n"
"Create a writable/readonly snapshot of the subvolume <source> with\n"
"the name <name> in the <dest> directory.",
NULL
},
{ do_delete_subvolume, 1,
"subvolume delete", "<subvolume>\n"
"Delete the subvolume <subvolume>.",
NULL
},
{ do_create_subvol, 1,
"subvolume create", "[<dest>/]<name>\n"
"Create a subvolume in <dest> (or the current directory if\n"
"not passed).",
NULL
},
{ do_subvol_list, 1, "subvolume list", "<path>\n"
"List the snapshot/subvolume of a filesystem.",
NULL
},
{ do_set_default_subvol, 2,
"subvolume set-default", "<id> <path>\n"
"Set the subvolume of the filesystem <path> which will be mounted\n"
"as default.",
NULL
},
{ do_find_newer, 2, "subvolume find-new", "<path> <last_gen>\n"
"List the recently modified files in a filesystem.",
NULL
},
{ do_defrag, -1,
"filesystem defragment", "[-vf] [-c[zlib,lzo]] [-s start] [-l len] [-t size] <file>|<dir> [<file>|<dir>...]\n"
"Defragment a file or a directory.",
"[-vcf] [-s start] [-l len] [-t size] <file>|<dir> [<file>|<dir>...]\n"
"Defragment file data or directory metadata.\n"
"-v be verbose\n"
"-c compress the file while defragmenting\n"
"-f flush data to disk immediately after defragmenting\n"
"-s start defragment only from byte onward\n"
"-l len defragment only up to len bytes\n"
"-t size minimal size of file to be considered for defragmenting\n"
},
{ do_fssync, 1,
"filesystem sync", "<path>\n"
"Force a sync on the filesystem <path>.",
NULL
},
{ do_resize, 2,
"filesystem resize", "[+/-]<newsize>[gkm]|max <filesystem>\n"
"Resize the file system. If 'max' is passed, the filesystem\n"
"will occupe all available space on the device.",
NULL
},
{ do_show_filesystem, 999,
"filesystem show", "[<device>|<uuid>|<label>]\n"
"Show the info of a btrfs filesystem. If no argument\n"
"is passed, info of all the btrfs filesystem are shown.",
NULL
},
{ do_df_filesystem, 1,
"filesystem df", "<path>\n"
"Show space usage information for a mount point.",
NULL
},
{ do_balance, 1,
"filesystem balance", "<path>\n"
"Balance the chunks across the device.",
NULL
},
{ do_scan, 999,
"device scan", "[<device>...]\n"
"Scan all device for or the passed device for a btrfs\n"
"filesystem.",
NULL
},
{ do_add_volume, -2,
"device add", "<device> [<device>...] <path>\n"
"Add a device to a filesystem.",
NULL
},
{ do_remove_volume, -2,
"device delete", "<device> [<device>...] <path>\n"
"Remove a device from a filesystem.",
NULL
},
{ 0, 0, 0, 0 }
};
static char *get_prgname(char *programname)
{
char *np;
np = strrchr(programname,'/');
if(!np)
np = programname;
else
np++;
return np;
}
static void print_help(char *programname, struct Command *cmd, int helptype)
{
char *pc;
printf("\t%s %s ", programname, cmd->verb );
if (helptype == ADVANCED_HELP && cmd->adv_help)
for(pc = cmd->adv_help; *pc; pc++){
putchar(*pc);
if(*pc == '\n')
printf("\t\t");
}
else
for(pc = cmd->help; *pc; pc++){
putchar(*pc);
if(*pc == '\n')
printf("\t\t");
}
putchar('\n');
}
static void help(char *np)
{
struct Command *cp;
printf("Usage:\n");
for( cp = commands; cp->verb; cp++ )
print_help(np, cp, BASIC_HELP);
printf("\n\t%s help|--help|-h\n\t\tShow the help.\n",np);
printf("\n\t%s <cmd> --help\n\t\tShow detailed help for a command or\n\t\t"
"subset of commands.\n",np);
printf("\n%s\n", BTRFS_BUILD_VERSION);
}
static int split_command(char *cmd, char ***commands)
{
int c, l;
char *p, *s;
for( *commands = 0, l = c = 0, p = s = cmd ; ; p++, l++ ){
if ( *p && *p != ' ' )
continue;
/* c + 2 so that we have room for the null */
(*commands) = realloc( (*commands), sizeof(char *)*(c + 2));
(*commands)[c] = strndup(s, l);
c++;
l = 0;
s = p+1;
if( !*p ) break;
}
(*commands)[c] = 0;
return c;
}
/*
This function checks if the passed command is ambiguous
*/
static int check_ambiguity(struct Command *cmd, char **argv){
int i;
struct Command *cp;
/* check for ambiguity */
for( i = 0 ; i < cmd->ncmds ; i++ ){
int match;
for( match = 0, cp = commands; cp->verb; cp++ ){
int j, skip;
char *s1, *s2;
if( cp->ncmds < i )
continue;
for( skip = 0, j = 0 ; j < i ; j++ )
if( strcmp(cmd->cmds[j], cp->cmds[j])){
skip=1;
break;
}
if(skip)
continue;
if( !strcmp(cmd->cmds[i], cp->cmds[i]))
continue;
for(s2 = cp->cmds[i], s1 = argv[i+1];
*s1 == *s2 && *s1; s1++, s2++ ) ;
if( !*s1 )
match++;
}
if(match){
int j;
fprintf(stderr, "ERROR: in command '");
for( j = 0 ; j <= i ; j++ )
fprintf(stderr, "%s%s",j?" ":"", argv[j+1]);
fprintf(stderr, "', '%s' is ambiguous\n",argv[j]);
return -2;
}
}
return 0;
}
/*
* This function, compacts the program name and the command in the first
* element of the '*av' array
*/
static int prepare_args(int *ac, char ***av, char *prgname, struct Command *cmd ){
char **ret;
int i;
char *newname;
ret = (char **)malloc(sizeof(char*)*(*ac+1));
newname = (char*)malloc(strlen(prgname)+strlen(cmd->verb)+2);
if( !ret || !newname ){
free(ret);
free(newname);
return -1;
}
ret[0] = newname;
for(i=0; i < *ac ; i++ )
ret[i+1] = (*av)[i];
strcpy(newname, prgname);
strcat(newname, " ");
strcat(newname, cmd->verb);
(*ac)++;
*av = ret;
return 0;
}
/*
This function performs the following jobs:
- show the help if '--help' or 'help' or '-h' are passed
- verify that a command is not ambiguous, otherwise show which
part of the command is ambiguous
- if after a (even partial) command there is '--help' show detailed help
for all the matching commands
- if the command doesn't match show an error
- finally, if a command matches, they return which command matched and
the arguments
The function return 0 in case of help is requested; <0 in case
of uncorrect command; >0 in case of matching commands
argc, argv are the arg-counter and arg-vector (input)
*nargs_ is the number of the arguments after the command (output)
**cmd_ is the invoked command (output)
***args_ are the arguments after the command
*/
static int parse_args(int argc, char **argv,
CommandFunction *func_,
int *nargs_, char **cmd_, char ***args_ )
{
struct Command *cp;
struct Command *matchcmd=0;
char *prgname = get_prgname(argv[0]);
int i=0, helprequested=0;
if( argc < 2 || !strcmp(argv[1], "help") ||
!strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")){
help(prgname);
return 0;
}
for( cp = commands; cp->verb; cp++ )
if( !cp->ncmds)
cp->ncmds = split_command(cp->verb, &(cp->cmds));
for( cp = commands; cp->verb; cp++ ){
int match;
if( argc-1 < cp->ncmds )
continue;
for( match = 1, i = 0 ; i < cp->ncmds ; i++ ){
char *s1, *s2;
s1 = cp->cmds[i];
s2 = argv[i+1];
for(s2 = cp->cmds[i], s1 = argv[i+1];
*s1 == *s2 && *s1;
s1++, s2++ ) ;
if( *s1 ){
match=0;
break;
}
}
/* If you understand why this code works ...
you are a genious !! */
if(argc>i+1 && !strcmp(argv[i+1],"--help")){
if(!helprequested)
printf("Usage:\n");
print_help(prgname, cp, ADVANCED_HELP);
helprequested=1;
continue;
}
if(!match)
continue;
matchcmd = cp;
*nargs_ = argc-matchcmd->ncmds-1;
*cmd_ = matchcmd->verb;
*args_ = argv+matchcmd->ncmds+1;
*func_ = cp->func;
break;
}
if(helprequested){
printf("\n%s\n", BTRFS_BUILD_VERSION);
return 0;
}
if(!matchcmd){
fprintf( stderr, "ERROR: unknown command '%s'\n",argv[1]);
help(prgname);
return -1;
}
if(check_ambiguity(matchcmd, argv))
return -2;
/* check the number of argument */
if (matchcmd->nargs < 0 && matchcmd->nargs < -*nargs_ ){
fprintf(stderr, "ERROR: '%s' requires minimum %d arg(s)\n",
matchcmd->verb, -matchcmd->nargs);
return -2;
}
if(matchcmd->nargs >= 0 && matchcmd->nargs != *nargs_ && matchcmd->nargs != 999){
fprintf(stderr, "ERROR: '%s' requires %d arg(s)\n",
matchcmd->verb, matchcmd->nargs);
return -2;
}
if (prepare_args( nargs_, args_, prgname, matchcmd )){
fprintf(stderr, "ERROR: not enough memory\\n");
return -20;
}
return 1;
}
int main(int ac, char **av )
{
char *cmd=0, **args=0;
int nargs=0, r;
CommandFunction func=0;
r = parse_args(ac, av, &func, &nargs, &cmd, &args);
if( r <= 0 ){
/* error or no command to parse*/
exit(-r);
}
exit(func(nargs, args));
}
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