diff options
Diffstat (limited to 'libblkid/sysfs2.c')
-rw-r--r-- | libblkid/sysfs2.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/libblkid/sysfs2.c b/libblkid/sysfs2.c new file mode 100644 index 000000000..a04b20a37 --- /dev/null +++ b/libblkid/sysfs2.c @@ -0,0 +1,119 @@ +/* + * sysfs based topology -- gathers topology information from Linux sysfs + * + * Copyright (C) 2009 Karel Zak <kzak@redhat.com> + * + * This file may be redistributed under the terms of the + * GNU Lesser General Public License. + * + * For more information see Linux kernel Documentation/ABI/testing/sysfs-block. + */ +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <inttypes.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <unistd.h> +#include <errno.h> + +#include "sysfs.h" +#include "topology.h" + +/* + * Sysfs topology values (since 2.6.31, May 2009). + */ +static struct topology_val { + + /* /sys/dev/block/<maj>:<min>/<ATTR> */ + const char *attr; + + /* functions to set probing resut */ + int (*set_ulong)(blkid_probe, unsigned long); + int (*set_int)(blkid_probe, int); + +} topology_vals[] = { + { "alignment_offset", NULL, blkid_topology_set_alignment_offset }, + { "queue/minimum_io_size", blkid_topology_set_minimum_io_size }, + { "queue/optimal_io_size", blkid_topology_set_optimal_io_size }, + { "queue/physical_block_size", blkid_topology_set_physical_sector_size }, +}; + +static int probe_sysfs_tp(blkid_probe pr, + const struct blkid_idmag *mag __attribute__((__unused__))) +{ + dev_t dev, disk = 0; + int rc; + struct sysfs_cxt sysfs = UL_SYSFSCXT_EMPTY, + parent = UL_SYSFSCXT_EMPTY; + size_t i, count = 0; + + dev = blkid_probe_get_devno(pr); + if (!dev || sysfs_init(&sysfs, dev, NULL) != 0) + return 1; + + rc = 1; /* nothing (default) */ + + for (i = 0; i < ARRAY_SIZE(topology_vals); i++) { + struct topology_val *val = &topology_vals[i]; + int ok = sysfs_has_attribute(&sysfs, val->attr); + + rc = 1; /* nothing */ + + if (!ok) { + if (!disk) { + /* + * Read atrributes from "disk" if the current + * device is a partition. + */ + disk = blkid_probe_get_wholedisk_devno(pr); + if (disk && disk != dev) { + if (sysfs_init(&parent, disk, NULL) != 0) + goto done; + + sysfs.parent = &parent; + ok = sysfs_has_attribute(&sysfs, + val->attr); + } + } + if (!ok) + continue; /* attribute does not exist */ + } + + if (val->set_ulong) { + uint64_t data; + + if (sysfs_read_u64(&sysfs, val->attr, &data) != 0) + continue; + rc = val->set_ulong(pr, (unsigned long) data); + + } else if (val->set_int) { + int64_t data; + + if (sysfs_read_s64(&sysfs, val->attr, &data) != 0) + continue; + rc = val->set_int(pr, (int) data); + } + + if (rc < 0) + goto done; /* error */ + if (rc == 0) + count++; + } + +done: + sysfs_deinit(&sysfs); + sysfs_deinit(&parent); + + if (count) + return 0; /* success */ + return rc; /* error or nothing */ +} + +const struct blkid_idinfo sysfs_tp_idinfo = +{ + .name = "sysfs", + .probefunc = probe_sysfs_tp, + .magics = BLKID_NONE_MAGIC +}; + |