can_clone_file.c File Reference

#include <stdlib.h>
#include "config.h"

Go to the source code of this file.

Functions
int	main (int argc, char *argv[])

Function Documentation

main()

int main	(	int	argc,
		char *	argv[]
	)

Definition at line 56 of file can_clone_file.c.

                             {
#ifdef HAVE_CLONEFILE
    struct statfs fs;
    struct attrlist attribute_list;
    struct {
        uint32_t size;
        vol_capabilities_attr_t capabilities;
    } volume_attributes;
 
    if (statfs(".", &fs) < 0) {
        fprintf(stderr, "%s: can't get mount point of current directory: %s\n", argv[0], strerror(errno));
        exit(1);
    }
 
    /* Not all volumes support clonefile().  A volume can be tested for
       clonefile() support by using getattrlist(2) to get the volume
       capabilities attribute ATTR_VOL_CAPABILITIES, and then testing the
       VOL_CAP_INT_CLONE flag. */
 
    memset(&attribute_list, 0, sizeof(attribute_list));
    attribute_list.bitmapcount = ATTR_BIT_MAP_COUNT;
    attribute_list.volattr = ATTR_VOL_INFO | ATTR_VOL_CAPABILITIES;
    memset(&volume_attributes, 0, sizeof(volume_attributes));
 
    if (getattrlist(fs.f_mntonname, &attribute_list, &volume_attributes, sizeof(volume_attributes), 0) < 0) {
        fprintf(stderr, "%s: can't get volume capabilities of '%s': %s\n", argv[0], fs.f_mntonname, strerror(errno));
        exit(1);
    }
 
    if (volume_attributes.capabilities.capabilities[VOL_CAPABILITIES_INTERFACES] & VOL_CAP_INT_CLONE) {
        exit(0);
    }
#elif defined(HAVE_FICLONERANGE)
    char namea[32] = "a.fioclone.XXXXXX";
    char nameb[32] = "b.fioclone.XXXXXX";
    int fda, fdb, ret;
    struct file_clone_range range;
 
    if ((fda = mkstemp(namea)) < 0) {
        fprintf(stderr, "can't create temp file a: %s\n", strerror(errno));
        exit(1);
    }
    if ((fdb = mkstemp(nameb)) < 0) {
        fprintf(stderr, "can't create temp file b: %s\n", strerror(errno));
        (void)close(fda);
        (void)remove(namea);
        exit(1);
    }
    if (write(fda, "test\n", 5) < 0) {
        fprintf(stderr, "can't write temp file a: %s\n", strerror(errno));
        (void)close(fda);
        (void)remove(namea);
        close(fdb);
        (void)remove(nameb);
        exit(1);
    }
    range.src_fd = fda;
    range.src_offset = 0;
    range.src_length = 0;
    range.dest_offset = 0;
    ret = ioctl(fdb, FICLONERANGE, &range);
    (void)close(fda);
    (void)close(fdb);
    (void)remove(namea);
    (void)remove(nameb);
    if (ret >= 0) {
        exit(0);
    }
#endif
 
    exit(1);
}

References argv, close, test-lz4-list::exit, ioctl, memset(), capstone::range, statfs, and write.