forked from Mirrors/btrfs-progs
72 lines
1.5 KiB
C
72 lines
1.5 KiB
C
#include "kerncompat.h"
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#include "common/utils.h"
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#include <unistd.h>
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#include <stdlib.h>
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#include <limits.h>
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#include <sys/ioctl.h>
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#include <ioctl.h>
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#if BTRFS_FLAT_INCLUDES
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#include "ctree.h"
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#else
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#include <btrfs/ctree.h>
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#endif /* BTRFS_FLAT_INCLUDES */
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/*
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* This function should be only used when parsing command arg, it won't return
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* error to its caller and rather exit directly just like usage().
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*/
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u64 arg_strtou64(const char *str)
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{
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u64 value;
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char *ptr_parse_end = NULL;
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value = strtoull(str, &ptr_parse_end, 0);
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if (ptr_parse_end && *ptr_parse_end != '\0') {
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fprintf(stderr, "ERROR: %s is not a valid numeric value.\n",
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str);
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exit(1);
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}
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/*
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* if we pass a negative number to strtoull, it will return an
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* unexpected number to us, so let's do the check ourselves.
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*/
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if (str[0] == '-') {
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fprintf(stderr, "ERROR: %s: negative value is invalid.\n",
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str);
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exit(1);
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}
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if (value == ULLONG_MAX) {
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fprintf(stderr, "ERROR: %s is too large.\n", str);
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exit(1);
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}
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return value;
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}
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/*
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* For a given:
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* - file or directory return the containing tree root id
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* - subvolume return its own tree id
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* - BTRFS_EMPTY_SUBVOL_DIR_OBJECTID (directory with ino == 2) the result is
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* undefined and function returns -1
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*/
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int lookup_path_rootid(int fd, u64 *rootid)
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{
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struct btrfs_ioctl_ino_lookup_args args;
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int ret;
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memset(&args, 0, sizeof(args));
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args.treeid = 0;
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args.objectid = BTRFS_FIRST_FREE_OBJECTID;
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ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &args);
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if (ret < 0)
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return -errno;
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*rootid = args.treeid;
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return 0;
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}
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