Kernel since 4.14 supports setting of logical block size[1]. It allows to create loop devices that report logical block size different from 512. Add support for this feature to losetup. References: [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/block/loop.c?id=89e4fdecb51cf5535867026274bc97de9480ade5 Signed-off-by: Stanislav Brabec <sbrabec@xxxxxxx> Cc: Ming Lei <ming.lei@xxxxxxxxxx> Cc: Hannes Reinecke <hare@xxxxxxxx> Cc: Omar Sandoval <osandov@xxxxxx> Cc: Jens Axboe <axboe@xxxxxxxxx> --- include/loopdev.h | 4 ++++ lib/loopdev.c | 46 ++++++++++++++++++++++++++++++++++++++++++++ sys-utils/losetup.8 | 3 +++ sys-utils/losetup.c | 55 ++++++++++++++++++++++++++++++++++++++++------------- 4 files changed, 95 insertions(+), 13 deletions(-) diff --git a/include/loopdev.h b/include/loopdev.h index 953d2db89..20cf9b183 100644 --- a/include/loopdev.h +++ b/include/loopdev.h @@ -24,6 +24,7 @@ /* #define LOOP_CHANGE_FD 0x4C06 */ #define LOOP_SET_CAPACITY 0x4C07 #define LOOP_SET_DIRECT_IO 0x4C08 +#define LOOP_SET_BLOCK_SIZE 0x4C09 /* /dev/loop-control interface */ #ifndef LOOP_CTL_ADD @@ -55,6 +56,7 @@ struct loop_info64 { uint64_t lo_rdevice; uint64_t lo_offset; uint64_t lo_sizelimit; /* bytes, 0 == max available */ + uint64_t lo_blocksize; uint32_t lo_number; uint32_t lo_encrypt_type; uint32_t lo_encrypt_key_size; @@ -173,11 +175,13 @@ int loopcxt_set_offset(struct loopdev_cxt *lc, uint64_t offset); int loopcxt_set_sizelimit(struct loopdev_cxt *lc, uint64_t sizelimit); int loopcxt_set_flags(struct loopdev_cxt *lc, uint32_t flags); int loopcxt_set_backing_file(struct loopdev_cxt *lc, const char *filename); +int loopcxt_set_blocksize(struct loopdev_cxt *lc, uint64_t blocksize); extern char *loopcxt_get_backing_file(struct loopdev_cxt *lc); extern int loopcxt_get_backing_devno(struct loopdev_cxt *lc, dev_t *devno); extern int loopcxt_get_backing_inode(struct loopdev_cxt *lc, ino_t *ino); extern int loopcxt_get_offset(struct loopdev_cxt *lc, uint64_t *offset); +extern int loopcxt_get_blocksize(struct loopdev_cxt *lc, uint64_t *blocksize); extern int loopcxt_get_sizelimit(struct loopdev_cxt *lc, uint64_t *size); extern int loopcxt_get_encrypt_type(struct loopdev_cxt *lc, uint32_t *type); extern const char *loopcxt_get_crypt_name(struct loopdev_cxt *lc); diff --git a/lib/loopdev.c b/lib/loopdev.c index 8c653a361..4863219c5 100644 --- a/lib/loopdev.c +++ b/lib/loopdev.c @@ -735,6 +735,34 @@ int loopcxt_get_offset(struct loopdev_cxt *lc, uint64_t *offset) return rc; } +/* + * @lc: context + * @blocksize: returns logical blocksize for the given device + * + * Returns: <0 on error, 0 on success + */ +int loopcxt_get_blocksize(struct loopdev_cxt *lc, uint64_t *blocksize) +{ + struct sysfs_cxt *sysfs = loopcxt_get_sysfs(lc); + int rc = -EINVAL; + + if (sysfs) + rc = sysfs_read_u64(sysfs, "queue/logical_block_size", blocksize); + + if (rc && loopcxt_ioctl_enabled(lc)) { + struct loop_info64 *lo = loopcxt_get_info(lc); + if (lo) { + if (blocksize) + *blocksize = lo->lo_blocksize; + rc = 0; + } else + rc = -errno; + } + + DBG(CXT, ul_debugobj(lc, "get_blocksize [rc=%d]", rc)); + return rc; +} + /* * @lc: context * @sizelimit: returns size limit for the given device @@ -1398,6 +1426,24 @@ int loopcxt_set_dio(struct loopdev_cxt *lc, unsigned long use_dio) return 0; } +int loopcxt_set_blocksize(struct loopdev_cxt *lc, unsigned long blocksize) +{ + int fd = loopcxt_get_fd(lc); + + if (fd < 0) + return -EINVAL; + + /* Kernels prior to v4.14 don't support this ioctl */ + if (ioctl(fd, LOOP_SET_BLOCK_SIZE, blocksize) < 0) { + int rc = -errno; + DBG(CXT, ul_debugobj(lc, "LOOP_SET_BLOCK_SIZE failed: %m")); + return rc; + } + + DBG(CXT, ul_debugobj(lc, "logical block size set")); + return 0; +} + int loopcxt_delete_device(struct loopdev_cxt *lc) { int fd = loopcxt_get_fd(lc); diff --git a/sys-utils/losetup.8 b/sys-utils/losetup.8 index 98a8e70d6..41aedd8e5 100644 --- a/sys-utils/losetup.8 +++ b/sys-utils/losetup.8 @@ -116,6 +116,9 @@ The data start is moved \fIoffset\fP bytes into the specified file or device. .IP "\fB\-\-sizelimit \fIsize\fP" The data end is set to no more than \fIsize\fP bytes after the data start. .TP +.BR \-b , " \-\-logical-blocksize " \fIsize +Set the logical block size of the loop device in bytes. +.TP .BR \-c , " \-\-set\-capacity " \fIloopdev Force the loop driver to reread the size of the file associated with the specified loop device. diff --git a/sys-utils/losetup.c b/sys-utils/losetup.c index bbff98389..7837f5833 100644 --- a/sys-utils/losetup.c +++ b/sys-utils/losetup.c @@ -36,6 +36,7 @@ enum { A_FIND_FREE, /* find first unused */ A_SET_CAPACITY, /* set device capacity */ A_SET_DIRECT_IO, /* set accessing backing file by direct io */ + A_SET_BLOCKSIZE, /* set logical block size of the loop device */ }; enum { @@ -50,6 +51,7 @@ enum { COL_RO, COL_SIZELIMIT, COL_DIO, + COL_BLOCKSIZE, }; /* basic output flags */ @@ -76,6 +78,7 @@ static struct colinfo infos[] = { [COL_SIZELIMIT] = { "SIZELIMIT", 5, SCOLS_FL_RIGHT, N_("size limit of the file in bytes")}, [COL_MAJMIN] = { "MAJ:MIN", 3, 0, N_("loop device major:minor number")}, [COL_DIO] = { "DIO", 1, SCOLS_FL_RIGHT, N_("access backing file with direct-io")}, + [COL_BLOCKSIZE] = { "BLOCKSIZE", 4, SCOLS_FL_RIGHT, N_("logical block size in bytes")}, }; static int columns[ARRAY_SIZE(infos) * 2] = {-1}; @@ -136,6 +139,8 @@ static int printf_loopdev(struct loopdev_cxt *lc) if (loopcxt_get_sizelimit(lc, &x) == 0 && x) printf(_(", sizelimit %ju"), x); + if (loopcxt_get_blocksize(lc, &x) == 0 && x) + printf(_(", blocksize %ju"), x); printf("\n"); return 0; } @@ -157,6 +162,8 @@ static int printf_loopdev(struct loopdev_cxt *lc) if (e && *e) printf(_(", encryption %s (type %u)"), e, type); } + if (loopcxt_get_blocksize(lc, &x) == 0 && x) + printf(_(", blocksize %ju"), x); printf("\n"); return 0; } @@ -280,6 +287,10 @@ static int set_scols_data(struct loopdev_cxt *lc, struct libscols_line *ln) case COL_PARTSCAN: p = loopcxt_is_partscan(lc) ? "1" : "0"; break; + case COL_BLOCKSIZE: + if (loopcxt_get_blocksize(lc, &x) == 0) + xasprintf(&np, "%jd", x); + break; default: return -EINVAL; } @@ -404,6 +415,7 @@ static void __attribute__((__noreturn__)) usage(void) fputs(USAGE_SEPARATOR, out); fputs(_(" -o, --offset <num> start at offset <num> into file\n"), out); fputs(_(" --sizelimit <num> device is limited to <num> bytes of the file\n"), out); + fputs(_(" -b --logical-blocksize <size> set the logical block size to <size>\n"), out); fputs(_(" -P, --partscan create a partitioned loop device\n"), out); fputs(_(" -r, --read-only set up a read-only loop device\n"), out); fputs(_(" --direct-io[=<on|off>] open backing file with O_DIRECT\n"), out); @@ -566,11 +578,11 @@ int main(int argc, char **argv) struct loopdev_cxt lc; int act = 0, flags = 0, no_overlap = 0, c; char *file = NULL; - uint64_t offset = 0, sizelimit = 0; + uint64_t offset = 0, sizelimit = 0, blocksize = 0; int res = 0, showdev = 0, lo_flags = 0; char *outarg = NULL; int list = 0; - unsigned long use_dio = 0, set_dio = 0; + unsigned long use_dio = 0, set_dio = 0, set_blocksize = 0; enum { OPT_SIZELIMIT = CHAR_MAX + 1, @@ -589,6 +601,7 @@ int main(int argc, char **argv) { "associated", required_argument, NULL, 'j' }, { "json", no_argument, NULL, 'J' }, { "list", no_argument, NULL, 'l' }, + { "logical-blocksize", required_argument, NULL, 'b' }, { "noheadings", no_argument, NULL, 'n' }, { "offset", required_argument, NULL, 'o' }, { "output", required_argument, NULL, 'O' }, @@ -620,7 +633,7 @@ int main(int argc, char **argv) if (loopcxt_init(&lc, 0)) err(EXIT_FAILURE, _("failed to initialize loopcxt")); - while ((c = getopt_long(argc, argv, "ac:d:Dfhj:JlLno:O:PrvV", + while ((c = getopt_long(argc, argv, "ab:c:d:Dfhj:JlLno:O:PrvV", longopts, NULL)) != -1) { err_exclusive_options(c, longopts, excl, excl_st); @@ -629,6 +642,10 @@ int main(int argc, char **argv) case 'a': act = A_SHOW; break; + case 'b': + set_blocksize = 1; + blocksize = strtosize_or_err(optarg, _("failed to parse logical block size")); + break; case 'c': act = A_SET_CAPACITY; if (!is_loopdev(optarg) || @@ -727,6 +744,7 @@ int main(int argc, char **argv) columns[ncolumns++] = COL_RO; columns[ncolumns++] = COL_BACK_FILE; columns[ncolumns++] = COL_DIO; + columns[ncolumns++] = COL_BLOCKSIZE; } if (act == A_FIND_FREE && optind < argc) { @@ -747,12 +765,14 @@ int main(int argc, char **argv) /* * losetup [--list] <device> * OR - * losetup --direct-io[=off] <device> + * losetup {--direct-io[=off]|--logical-blocksize=size}... <device> */ - if (!set_dio) + if (!(set_dio || set_blocksize)) act = A_SHOW_ONE; - else + if (set_dio) act = A_SET_DIRECT_IO; + if (set_blocksize) + act = A_SET_BLOCKSIZE; if (!is_loopdev(argv[optind]) || loopcxt_set_device(&lc, argv[optind])) err(EXIT_FAILURE, _("%s: failed to use device"), @@ -799,8 +819,8 @@ int main(int argc, char **argv) if (showdev) printf("%s\n", loopcxt_get_device(&lc)); warn_size(file, sizelimit); - if (set_dio) - goto lo_set_dio; + if (set_dio || set_blocksize) + goto lo_set_post; } break; case A_DELETE: @@ -853,11 +873,20 @@ int main(int argc, char **argv) loopcxt_get_device(&lc)); break; case A_SET_DIRECT_IO: - lo_set_dio: - res = loopcxt_set_dio(&lc, use_dio); - if (res) - warn(_("%s: set direct io failed"), - loopcxt_get_device(&lc)); + case A_SET_BLOCKSIZE: + lo_set_post: + if (set_dio) { + res = loopcxt_set_dio(&lc, use_dio); + if (res) + warn(_("%s: set direct io failed"), + loopcxt_get_device(&lc)); + } + if (set_blocksize) { + res = loopcxt_set_blocksize(&lc, blocksize); + if (res) + warn(_("%s: set logical block size"), + loopcxt_get_device(&lc)); + } break; default: warnx(_("bad usage")); -- 2.14.1 -- Best Regards / S pozdravem, Stanislav Brabec software developer --------------------------------------------------------------------- SUSE LINUX, s. r. o. e-mail: sbrabec@xxxxxxxx Křižíkova 148/34 (Corso IIa) tel: +49 911 7405384547 186 00 Praha 8-Karlín fax: +420 284 084 001 Czech Republic http://www.suse.cz/ PGP: 830B 40D5 9E05 35D8 5E27 6FA3 717C 209F A04F CD76 -- To unsubscribe from this list: send the line "unsubscribe util-linux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
