From: Tejun Heo Date: Wed, 3 Sep 2008 07:01:48 +0000 (+0200) Subject: block: don't depend on consecutive minor space X-Git-Tag: v2.6.28-rc1~733^2~97 X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=f331c0296f2a9fee0d396a70598b954062603015 block: don't depend on consecutive minor space * Implement disk_devt() and part_devt() and use them to directly access devt instead of computing it from ->major and ->first_minor. Note that all references to ->major and ->first_minor outside of block layer is used to determine devt of the disk (the part0) and as ->major and ->first_minor will continue to represent devt for the disk, converting these users aren't strictly necessary. However, convert them for consistency. * Implement disk_max_parts() to avoid directly deferencing genhd->minors. * Update bdget_disk() such that it doesn't assume consecutive minor space. * Move devt computation from register_disk() to add_disk() and make it the only one (all other usages use the initially determined value). These changes clean up the code and will help disk->part dereference fix and extended block device numbers. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe --- diff --git a/block/genhd.c b/block/genhd.c index dc9ad4c..fa32d09 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -186,13 +186,14 @@ void add_disk(struct gendisk *disk) int retval; disk->flags |= GENHD_FL_UP; - blk_register_region(MKDEV(disk->major, disk->first_minor), - disk->minors, NULL, exact_match, exact_lock, disk); + disk->dev.devt = MKDEV(disk->major, disk->first_minor); + blk_register_region(disk_devt(disk), disk->minors, NULL, + exact_match, exact_lock, disk); register_disk(disk); blk_register_queue(disk); bdi = &disk->queue->backing_dev_info; - bdi_register_dev(bdi, MKDEV(disk->major, disk->first_minor)); + bdi_register_dev(bdi, disk_devt(disk)); retval = sysfs_create_link(&disk->dev.kobj, &bdi->dev->kobj, "bdi"); WARN_ON(retval); } @@ -205,8 +206,7 @@ void unlink_gendisk(struct gendisk *disk) sysfs_remove_link(&disk->dev.kobj, "bdi"); bdi_unregister(&disk->queue->backing_dev_info); blk_unregister_queue(disk); - blk_unregister_region(MKDEV(disk->major, disk->first_minor), - disk->minors); + blk_unregister_region(disk_devt(disk), disk->minors); } /** @@ -225,6 +225,38 @@ struct gendisk *get_gendisk(dev_t devt, int *partno) return kobj ? dev_to_disk(dev) : NULL; } +/** + * bdget_disk - do bdget() by gendisk and partition number + * @disk: gendisk of interest + * @partno: partition number + * + * Find partition @partno from @disk, do bdget() on it. + * + * CONTEXT: + * Don't care. + * + * RETURNS: + * Resulting block_device on success, NULL on failure. + */ +extern struct block_device *bdget_disk(struct gendisk *disk, int partno) +{ + dev_t devt = MKDEV(0, 0); + + if (partno == 0) + devt = disk_devt(disk); + else { + struct hd_struct *part = disk->part[partno - 1]; + + if (part && part->nr_sects) + devt = part_devt(part); + } + + if (likely(devt != MKDEV(0, 0))) + return bdget(devt); + return NULL; +} +EXPORT_SYMBOL(bdget_disk); + /* * print a full list of all partitions - intended for places where the root * filesystem can't be mounted and thus to give the victim some idea of what @@ -255,7 +287,7 @@ void __init printk_all_partitions(void) * option takes. */ printk("%02x%02x %10llu %s", - disk->major, disk->first_minor, + MAJOR(disk_devt(disk)), MINOR(disk_devt(disk)), (unsigned long long)get_capacity(disk) >> 1, disk_name(disk, 0, buf)); if (disk->driverfs_dev != NULL && @@ -266,15 +298,15 @@ void __init printk_all_partitions(void) printk(" (driver?)\n"); /* now show the partitions */ - for (n = 0; n < disk->minors - 1; ++n) { - if (disk->part[n] == NULL) - continue; - if (disk->part[n]->nr_sects == 0) + for (n = 0; n < disk_max_parts(disk); ++n) { + struct hd_struct *part = disk->part[n]; + + if (!part || !part->nr_sects) continue; printk(" %02x%02x %10llu %s\n", - disk->major, n + 1 + disk->first_minor, - (unsigned long long)disk->part[n]->nr_sects >> 1, - disk_name(disk, n + 1, buf)); + MAJOR(part_devt(part)), MINOR(part_devt(part)), + (unsigned long long)part->nr_sects >> 1, + disk_name(disk, part->partno, buf)); } } class_dev_iter_exit(&iter); @@ -343,26 +375,27 @@ static int show_partition(struct seq_file *seqf, void *v) char buf[BDEVNAME_SIZE]; /* Don't show non-partitionable removeable devices or empty devices */ - if (!get_capacity(sgp) || - (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE))) + if (!get_capacity(sgp) || (!disk_max_parts(sgp) && + (sgp->flags & GENHD_FL_REMOVABLE))) return 0; if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO) return 0; /* show the full disk and all non-0 size partitions of it */ seq_printf(seqf, "%4d %4d %10llu %s\n", - sgp->major, sgp->first_minor, + MAJOR(disk_devt(sgp)), MINOR(disk_devt(sgp)), (unsigned long long)get_capacity(sgp) >> 1, disk_name(sgp, 0, buf)); - for (n = 0; n < sgp->minors - 1; n++) { - if (!sgp->part[n]) + for (n = 0; n < disk_max_parts(sgp); n++) { + struct hd_struct *part = sgp->part[n]; + if (!part) continue; - if (sgp->part[n]->nr_sects == 0) + if (part->nr_sects == 0) continue; seq_printf(seqf, "%4d %4d %10llu %s\n", - sgp->major, n + 1 + sgp->first_minor, - (unsigned long long)sgp->part[n]->nr_sects >> 1 , - disk_name(sgp, n + 1, buf)); + MAJOR(part_devt(part)), MINOR(part_devt(part)), + (unsigned long long)part->nr_sects >> 1, + disk_name(sgp, part->partno, buf)); } return 0; @@ -578,7 +611,8 @@ static int diskstats_show(struct seq_file *seqf, void *v) disk_round_stats(gp); preempt_enable(); seq_printf(seqf, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n", - gp->major, gp->first_minor, disk_name(gp, 0, buf), + MAJOR(disk_devt(gp)), MINOR(disk_devt(gp)), + disk_name(gp, 0, buf), disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]), (unsigned long long)disk_stat_read(gp, sectors[0]), jiffies_to_msecs(disk_stat_read(gp, ticks[0])), @@ -590,7 +624,7 @@ static int diskstats_show(struct seq_file *seqf, void *v) jiffies_to_msecs(disk_stat_read(gp, time_in_queue))); /* now show all non-0 size partitions of it */ - for (n = 0; n < gp->minors - 1; n++) { + for (n = 0; n < disk_max_parts(gp); n++) { struct hd_struct *hd = gp->part[n]; if (!hd || !hd->nr_sects) @@ -601,8 +635,8 @@ static int diskstats_show(struct seq_file *seqf, void *v) preempt_enable(); seq_printf(seqf, "%4d %4d %s %lu %lu %llu " "%u %lu %lu %llu %u %u %u %u\n", - gp->major, n + gp->first_minor + 1, - disk_name(gp, n + 1, buf), + MAJOR(part_devt(hd)), MINOR(part_devt(hd)), + disk_name(gp, hd->partno, buf), part_stat_read(hd, ios[0]), part_stat_read(hd, merges[0]), (unsigned long long)part_stat_read(hd, sectors[0]), @@ -661,11 +695,22 @@ dev_t blk_lookup_devt(const char *name, int partno) while ((dev = class_dev_iter_next(&iter))) { struct gendisk *disk = dev_to_disk(dev); - if (!strcmp(dev->bus_id, name) && partno < disk->minors) { - devt = MKDEV(MAJOR(dev->devt), - MINOR(dev->devt) + partno); - break; + if (strcmp(dev->bus_id, name)) + continue; + if (partno < 0 || partno > disk_max_parts(disk)) + continue; + + if (partno == 0) + devt = disk_devt(disk); + else { + struct hd_struct *part = disk->part[partno - 1]; + + if (!part || !part->nr_sects) + continue; + + devt = part_devt(part); } + break; } class_dev_iter_exit(&iter); return devt; @@ -755,7 +800,7 @@ void set_disk_ro(struct gendisk *disk, int flag) { int i; disk->policy = flag; - for (i = 0; i < disk->minors - 1; i++) + for (i = 0; i < disk_max_parts(disk); i++) if (disk->part[i]) disk->part[i]->policy = flag; } diff --git a/block/ioctl.c b/block/ioctl.c index d77f5e2..403f7d7e 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -29,7 +29,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user if (bdev != bdev->bd_contains) return -EINVAL; partno = p.pno; - if (partno <= 0 || partno >= disk->minors) + if (partno <= 0 || partno > disk_max_parts(disk)) return -EINVAL; switch (a.op) { case BLKPG_ADD_PARTITION: @@ -47,7 +47,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user mutex_lock(&bdev->bd_mutex); /* overlap? */ - for (i = 0; i < disk->minors - 1; i++) { + for (i = 0; i < disk_max_parts(disk); i++) { struct hd_struct *s = disk->part[i]; if (!s) @@ -96,7 +96,7 @@ static int blkdev_reread_part(struct block_device *bdev) struct gendisk *disk = bdev->bd_disk; int res; - if (disk->minors == 1 || bdev != bdev->bd_contains) + if (!disk_max_parts(disk) || bdev != bdev->bd_contains) return -EINVAL; if (!capable(CAP_SYS_ADMIN)) return -EACCES; diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c index 29b7a64..e1a90bb 100644 --- a/drivers/block/pktcdvd.c +++ b/drivers/block/pktcdvd.c @@ -2911,7 +2911,7 @@ static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev) if (!disk->queue) goto out_mem2; - pd->pkt_dev = MKDEV(disk->major, disk->first_minor); + pd->pkt_dev = MKDEV(pktdev_major, idx); ret = pkt_new_dev(pd, dev); if (ret) goto out_new_dev; diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c index 4b0d6c7..936466f 100644 --- a/drivers/block/ps3disk.c +++ b/drivers/block/ps3disk.c @@ -541,7 +541,7 @@ static int ps3disk_remove(struct ps3_system_bus_device *_dev) struct ps3disk_private *priv = dev->sbd.core.driver_data; mutex_lock(&ps3disk_mask_mutex); - __clear_bit(priv->gendisk->first_minor / PS3DISK_MINORS, + __clear_bit(MINOR(disk_devt(priv->gendisk)) / PS3DISK_MINORS, &ps3disk_mask); mutex_unlock(&ps3disk_mask_mutex); del_gendisk(priv->gendisk); diff --git a/drivers/char/random.c b/drivers/char/random.c index 7ce1ac4..6af435b 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -661,10 +661,10 @@ void add_disk_randomness(struct gendisk *disk) if (!disk || !disk->random) return; /* first major is 1, so we get >= 0x200 here */ - DEBUG_ENT("disk event %d:%d\n", disk->major, disk->first_minor); + DEBUG_ENT("disk event %d:%d\n", + MAJOR(disk_devt(disk)), MINOR(disk_devt(disk))); - add_timer_randomness(disk->random, - 0x100 + MKDEV(disk->major, disk->first_minor)); + add_timer_randomness(disk->random, 0x100 + disk_devt(disk)); } #endif diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index b262c00..c3de311 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -426,7 +426,7 @@ static int list_devices(struct dm_ioctl *param, size_t param_size) old_nl->next = (uint32_t) ((void *) nl - (void *) old_nl); disk = dm_disk(hc->md); - nl->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor)); + nl->dev = huge_encode_dev(disk_devt(disk)); nl->next = 0; strcpy(nl->name, hc->name); @@ -539,7 +539,7 @@ static int __dev_status(struct mapped_device *md, struct dm_ioctl *param) if (dm_suspended(md)) param->flags |= DM_SUSPEND_FLAG; - param->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor)); + param->dev = huge_encode_dev(disk_devt(disk)); /* * Yes, this will be out of date by the time it gets back diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c index 4de90ab..b745d8a 100644 --- a/drivers/md/dm-stripe.c +++ b/drivers/md/dm-stripe.c @@ -284,8 +284,8 @@ static int stripe_end_io(struct dm_target *ti, struct bio *bio, memset(major_minor, 0, sizeof(major_minor)); sprintf(major_minor, "%d:%d", - bio->bi_bdev->bd_disk->major, - bio->bi_bdev->bd_disk->first_minor); + MAJOR(disk_devt(bio->bi_bdev->bd_disk)), + MINOR(disk_devt(bio->bi_bdev->bd_disk))); /* * Test to see which stripe drive triggered the event diff --git a/drivers/md/dm.c b/drivers/md/dm.c index ace998c..a78caad 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1146,7 +1146,7 @@ static void unlock_fs(struct mapped_device *md); static void free_dev(struct mapped_device *md) { - int minor = md->disk->first_minor; + int minor = MINOR(disk_devt(md->disk)); if (md->suspended_bdev) { unlock_fs(md); @@ -1267,7 +1267,7 @@ static struct mapped_device *dm_find_md(dev_t dev) md = idr_find(&_minor_idr, minor); if (md && (md == MINOR_ALLOCED || - (dm_disk(md)->first_minor != minor) || + (MINOR(disk_devt(dm_disk(md))) != minor) || test_bit(DMF_FREEING, &md->flags))) { md = NULL; goto out; @@ -1318,7 +1318,8 @@ void dm_put(struct mapped_device *md) if (atomic_dec_and_lock(&md->holders, &_minor_lock)) { map = dm_get_table(md); - idr_replace(&_minor_idr, MINOR_ALLOCED, dm_disk(md)->first_minor); + idr_replace(&_minor_idr, MINOR_ALLOCED, + MINOR(disk_devt(dm_disk(md)))); set_bit(DMF_FREEING, &md->flags); spin_unlock(&_minor_lock); if (!dm_suspended(md)) { diff --git a/drivers/memstick/core/mspro_block.c b/drivers/memstick/core/mspro_block.c index d2d2318..82bf649 100644 --- a/drivers/memstick/core/mspro_block.c +++ b/drivers/memstick/core/mspro_block.c @@ -197,7 +197,7 @@ static int mspro_block_bd_open(struct inode *inode, struct file *filp) static int mspro_block_disk_release(struct gendisk *disk) { struct mspro_block_data *msb = disk->private_data; - int disk_id = disk->first_minor >> MSPRO_BLOCK_PART_SHIFT; + int disk_id = MINOR(disk_devt(disk)) >> MSPRO_BLOCK_PART_SHIFT; mutex_lock(&mspro_block_disk_lock); diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index ebc8b9d..97156b6 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -83,7 +83,7 @@ static void mmc_blk_put(struct mmc_blk_data *md) mutex_lock(&open_lock); md->usage--; if (md->usage == 0) { - int devidx = md->disk->first_minor >> MMC_SHIFT; + int devidx = MINOR(disk_devt(md->disk)) >> MMC_SHIFT; __clear_bit(devidx, dev_use); put_disk(md->disk); diff --git a/drivers/s390/block/dasd_proc.c b/drivers/s390/block/dasd_proc.c index 03c0e40..e3b5c4d 100644 --- a/drivers/s390/block/dasd_proc.c +++ b/drivers/s390/block/dasd_proc.c @@ -76,7 +76,8 @@ dasd_devices_show(struct seq_file *m, void *v) /* Print kdev. */ if (block->gdp) seq_printf(m, " at (%3d:%6d)", - block->gdp->major, block->gdp->first_minor); + MAJOR(disk_devt(block->gdp)), + MINOR(disk_devt(block->gdp))); else seq_printf(m, " at (???:??????)"); /* Print device name. */ diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index 711b300..9481e4a 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -114,7 +114,7 @@ dcssblk_assign_free_minor(struct dcssblk_dev_info *dev_info) found = 0; // test if minor available list_for_each_entry(entry, &dcssblk_devices, lh) - if (minor == entry->gd->first_minor) + if (minor == MINOR(disk_devt(entry->gd))) found++; if (!found) break; // got unused minor } @@ -397,7 +397,7 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char goto unload_seg; } sprintf(dev_info->gd->disk_name, "dcssblk%d", - dev_info->gd->first_minor); + MINOR(disk_devt(dev_info->gd))); list_add_tail(&dev_info->lh, &dcssblk_devices); if (!try_module_get(THIS_MODULE)) { diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index 27f5bfd..8dbe379 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -878,7 +878,7 @@ static void sr_kref_release(struct kref *kref) struct gendisk *disk = cd->disk; spin_lock(&sr_index_lock); - clear_bit(disk->first_minor, sr_index_bits); + clear_bit(MINOR(disk_devt(disk)), sr_index_bits); spin_unlock(&sr_index_lock); unregister_cdrom(&cd->cdi); diff --git a/fs/block_dev.c b/fs/block_dev.c index de0776c..72e0a28 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -892,7 +892,7 @@ int check_disk_change(struct block_device *bdev) if (bdops->revalidate_disk) bdops->revalidate_disk(bdev->bd_disk); - if (bdev->bd_disk->minors > 1) + if (disk_max_parts(bdev->bd_disk)) bdev->bd_invalidated = 1; return 1; } diff --git a/fs/partitions/check.c b/fs/partitions/check.c index b86aab1..e77fa14 100644 --- a/fs/partitions/check.c +++ b/fs/partitions/check.c @@ -134,7 +134,11 @@ char *disk_name(struct gendisk *hd, int partno, char *buf) const char *bdevname(struct block_device *bdev, char *buf) { - int partno = MINOR(bdev->bd_dev) - bdev->bd_disk->first_minor; + int partno = 0; + + if (bdev->bd_part) + partno = bdev->bd_part->partno; + return disk_name(bdev->bd_disk, partno, buf); } @@ -169,7 +173,7 @@ check_partition(struct gendisk *hd, struct block_device *bdev) if (isdigit(state->name[strlen(state->name)-1])) sprintf(state->name, "p"); - state->limit = hd->minors; + state->limit = disk_max_parts(hd) + 1; i = res = err = 0; while (!res && check_part[i]) { memset(&state->parts, 0, sizeof(state->parts)); @@ -416,7 +420,6 @@ void register_disk(struct gendisk *disk) int err; disk->dev.parent = disk->driverfs_dev; - disk->dev.devt = MKDEV(disk->major, disk->first_minor); strlcpy(disk->dev.bus_id, disk->disk_name, BUS_ID_SIZE); /* ewww... some of these buggers have / in the name... */ @@ -440,7 +443,7 @@ void register_disk(struct gendisk *disk) disk_sysfs_add_subdirs(disk); /* No minors to use for partitions */ - if (disk->minors == 1) + if (!disk_max_parts(disk)) goto exit; /* No such device (e.g., media were just removed) */ @@ -463,8 +466,8 @@ exit: kobject_uevent(&disk->dev.kobj, KOBJ_ADD); /* announce possible partitions */ - for (i = 1; i < disk->minors; i++) { - p = disk->part[i-1]; + for (i = 0; i < disk_max_parts(disk); i++) { + p = disk->part[i]; if (!p || !p->nr_sects) continue; kobject_uevent(&p->dev.kobj, KOBJ_ADD); @@ -482,7 +485,7 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev) if (res) return res; bdev->bd_invalidated = 0; - for (p = 1; p < disk->minors; p++) + for (p = 1; p <= disk_max_parts(disk); p++) delete_partition(disk, p); if (disk->fops->revalidate_disk) disk->fops->revalidate_disk(disk); @@ -545,7 +548,7 @@ void del_gendisk(struct gendisk *disk) int p; /* invalidate stuff */ - for (p = disk->minors - 1; p > 0; p--) { + for (p = disk_max_parts(disk); p > 0; p--) { invalidate_partition(disk, p); delete_partition(disk, p); } diff --git a/include/linux/genhd.h b/include/linux/genhd.h index d1723c0..0ff7532 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -111,10 +111,14 @@ struct hd_struct { #define GENHD_FL_FAIL 64 struct gendisk { + /* major, first_minor and minors are input parameters only, + * don't use directly. Use disk_devt() and disk_max_parts(). + */ int major; /* major number of driver */ int first_minor; int minors; /* maximum number of minors, =1 for * disks that can't be partitioned. */ + char disk_name[32]; /* name of major driver */ struct hd_struct **part; /* [indexed by minor - 1] */ struct block_device_operations *fops; @@ -152,6 +156,21 @@ static inline struct gendisk *part_to_disk(struct hd_struct *part) return NULL; } +static inline int disk_max_parts(struct gendisk *disk) +{ + return disk->minors - 1; +} + +static inline dev_t disk_devt(struct gendisk *disk) +{ + return disk->dev.devt; +} + +static inline dev_t part_devt(struct hd_struct *part) +{ + return part->dev.devt; +} + /* * Macros to operate on percpu disk statistics: * @@ -163,7 +182,7 @@ static inline struct hd_struct *disk_map_sector(struct gendisk *gendiskp, { struct hd_struct *part; int i; - for (i = 0; i < gendiskp->minors - 1; i++) { + for (i = 0; i < disk_max_parts(gendiskp); i++) { part = gendiskp->part[i]; if (part && part->start_sect <= sector && sector < part->start_sect + part->nr_sects) @@ -366,6 +385,7 @@ extern void add_disk(struct gendisk *disk); extern void del_gendisk(struct gendisk *gp); extern void unlink_gendisk(struct gendisk *gp); extern struct gendisk *get_gendisk(dev_t dev, int *partno); +extern struct block_device *bdget_disk(struct gendisk *disk, int partno); extern void set_device_ro(struct block_device *bdev, int flag); extern void set_disk_ro(struct gendisk *disk, int flag); @@ -553,11 +573,6 @@ extern void blk_register_region(dev_t devt, unsigned long range, void *data); extern void blk_unregister_region(dev_t devt, unsigned long range); -static inline struct block_device *bdget_disk(struct gendisk *disk, int partno) -{ - return bdget(MKDEV(disk->major, disk->first_minor) + partno); -} - #else /* CONFIG_BLOCK */ static inline void printk_all_partitions(void) { }