X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=block%2Fgenhd.c;h=1a4916e01732b68ebb9af5ff2fd831c78057d910;hb=c1d4c41f2fdfe66dea957b76d005affba3e56b26;hp=06a252f2b9676b718059ca79820515b48c5dcbe7;hpb=eddb2e26b5ee3c5da68ba4bf1921ba20e2097bff;p=safe%2Fjmp%2Flinux-2.6 diff --git a/block/genhd.c b/block/genhd.c index 06a252f..1a4916e 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -52,14 +53,21 @@ static struct device_type disk_type; */ struct hd_struct *disk_get_part(struct gendisk *disk, int partno) { - struct hd_struct *part; + struct hd_struct *part = NULL; + struct disk_part_tbl *ptbl; - if (unlikely(partno < 0 || partno >= disk_max_parts(disk))) + if (unlikely(partno < 0)) return NULL; + rcu_read_lock(); - part = rcu_dereference(disk->__part[partno]); - if (part) - get_device(part_to_dev(part)); + + ptbl = rcu_dereference(disk->part_tbl); + if (likely(partno < ptbl->len)) { + part = rcu_dereference(ptbl->part[partno]); + if (part) + get_device(part_to_dev(part)); + } + rcu_read_unlock(); return part; @@ -80,17 +88,24 @@ EXPORT_SYMBOL_GPL(disk_get_part); void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk, unsigned int flags) { + struct disk_part_tbl *ptbl; + + rcu_read_lock(); + ptbl = rcu_dereference(disk->part_tbl); + piter->disk = disk; piter->part = NULL; if (flags & DISK_PITER_REVERSE) - piter->idx = disk_max_parts(piter->disk) - 1; - else if (flags & DISK_PITER_INCL_PART0) + piter->idx = ptbl->len - 1; + else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0)) piter->idx = 0; else piter->idx = 1; piter->flags = flags; + + rcu_read_unlock(); } EXPORT_SYMBOL_GPL(disk_part_iter_init); @@ -105,34 +120,41 @@ EXPORT_SYMBOL_GPL(disk_part_iter_init); */ struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) { + struct disk_part_tbl *ptbl; int inc, end; /* put the last partition */ disk_put_part(piter->part); piter->part = NULL; + /* get part_tbl */ rcu_read_lock(); + ptbl = rcu_dereference(piter->disk->part_tbl); /* determine iteration parameters */ if (piter->flags & DISK_PITER_REVERSE) { inc = -1; - if (piter->flags & DISK_PITER_INCL_PART0) + if (piter->flags & (DISK_PITER_INCL_PART0 | + DISK_PITER_INCL_EMPTY_PART0)) end = -1; else end = 0; } else { inc = 1; - end = disk_max_parts(piter->disk); + end = ptbl->len; } /* iterate to the next partition */ for (; piter->idx != end; piter->idx += inc) { struct hd_struct *part; - part = rcu_dereference(piter->disk->__part[piter->idx]); + part = rcu_dereference(ptbl->part[piter->idx]); if (!part) continue; - if (!(piter->flags & DISK_PITER_INCL_EMPTY) && !part->nr_sects) + if (!part->nr_sects && + !(piter->flags & DISK_PITER_INCL_EMPTY) && + !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && + piter->idx == 0)) continue; get_device(part_to_dev(part)); @@ -163,6 +185,12 @@ void disk_part_iter_exit(struct disk_part_iter *piter) } EXPORT_SYMBOL_GPL(disk_part_iter_exit); +static inline int sector_in_part(struct hd_struct *part, sector_t sector) +{ + return part->start_sect <= sector && + sector < part->start_sect + part->nr_sects; +} + /** * disk_map_sector_rcu - map sector to partition * @disk: gendisk of interest @@ -176,20 +204,29 @@ EXPORT_SYMBOL_GPL(disk_part_iter_exit); * while preemption is disabled. * * RETURNS: - * Found partition on success, NULL if there's no matching partition. + * Found partition on success, part0 is returned if no partition matches */ struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector) { + struct disk_part_tbl *ptbl; + struct hd_struct *part; int i; - for (i = 1; i < disk_max_parts(disk); i++) { - struct hd_struct *part = rcu_dereference(disk->__part[i]); + ptbl = rcu_dereference(disk->part_tbl); + + part = rcu_dereference(ptbl->last_lookup); + if (part && sector_in_part(part, sector)) + return part; + + for (i = 1; i < ptbl->len; i++) { + part = rcu_dereference(ptbl->part[i]); - if (part && part->start_sect <= sector && - sector < part->start_sect + part->nr_sects) + if (part && sector_in_part(part, sector)) { + rcu_assign_pointer(ptbl->last_lookup, part); return part; + } } - return NULL; + return &disk->part0; } EXPORT_SYMBOL_GPL(disk_map_sector_rcu); @@ -223,6 +260,22 @@ void blkdev_show(struct seq_file *seqf, off_t offset) } #endif /* CONFIG_PROC_FS */ +/** + * register_blkdev - register a new block device + * + * @major: the requested major device number [1..255]. If @major=0, try to + * allocate any unused major number. + * @name: the name of the new block device as a zero terminated string + * + * The @name must be unique within the system. + * + * The return value depends on the @major input parameter. + * - if a major device number was requested in range [1..255] then the + * function returns zero on success, or a negative error code + * - if any unused major number was requested with @major=0 parameter + * then the return value is the allocated major number in range + * [1..255] or a negative error code otherwise + */ int register_blkdev(unsigned int major, const char *name) { struct blk_major_name **n, *p; @@ -338,7 +391,6 @@ static int blk_mangle_minor(int minor) /** * blk_alloc_devt - allocate a dev_t for a partition * @part: partition to allocate dev_t for - * @gfp_mask: memory allocation flag * @devt: out parameter for resulting dev_t * * Allocate a dev_t for block device. @@ -458,14 +510,37 @@ static int exact_lock(dev_t devt, void *data) * * This function registers the partitioning information in @disk * with the kernel. + * + * FIXME: error handling */ void add_disk(struct gendisk *disk) { struct backing_dev_info *bdi; + dev_t devt; int retval; + /* minors == 0 indicates to use ext devt from part0 and should + * be accompanied with EXT_DEVT flag. Make sure all + * parameters make sense. + */ + WARN_ON(disk->minors && !(disk->major || disk->first_minor)); + WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT)); + disk->flags |= GENHD_FL_UP; - disk_to_dev(disk)->devt = MKDEV(disk->major, disk->first_minor); + + retval = blk_alloc_devt(&disk->part0, &devt); + if (retval) { + WARN_ON(1); + return; + } + disk_to_dev(disk)->devt = devt; + + /* ->major and ->first_minor aren't supposed to be + * dereferenced from here on, but set them just in case. + */ + disk->major = MAJOR(devt); + disk->first_minor = MINOR(devt); + blk_register_region(disk_devt(disk), disk->minors, NULL, exact_match, exact_lock, disk); register_disk(disk); @@ -492,7 +567,7 @@ void unlink_gendisk(struct gendisk *disk) /** * get_gendisk - get partitioning information for a given device * @devt: device to get partitioning information for - * @part: returned partition index + * @partno: returned partition index * * This function gets the structure containing partitioning * information for the given device @devt. @@ -535,13 +610,13 @@ struct gendisk *get_gendisk(dev_t devt, int *partno) * RETURNS: * Resulting block_device on success, NULL on failure. */ -extern struct block_device *bdget_disk(struct gendisk *disk, int partno) +struct block_device *bdget_disk(struct gendisk *disk, int partno) { struct hd_struct *part; struct block_device *bdev = NULL; part = disk_get_part(disk, partno); - if (part && (part->nr_sects || partno == 0)) + if (part) bdev = bdget(part_devt(part)); disk_put_part(part); @@ -580,24 +655,24 @@ void __init printk_all_partitions(void) * numbers in hex - the same format as the root= * option takes. */ - printk("%s %10llu %s", - bdevt_str(disk_devt(disk), devt_buf), - (unsigned long long)get_capacity(disk) >> 1, - disk_name(disk, 0, name_buf)); - if (disk->driverfs_dev != NULL && - disk->driverfs_dev->driver != NULL) - printk(" driver: %s\n", - disk->driverfs_dev->driver->name); - else - printk(" (driver?)\n"); + disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0); + while ((part = disk_part_iter_next(&piter))) { + bool is_part0 = part == &disk->part0; - /* now show the partitions */ - disk_part_iter_init(&piter, disk, 0); - while ((part = disk_part_iter_next(&piter))) - printk(" %s %10llu %s\n", + printk("%s%s %10llu %s", is_part0 ? "" : " ", bdevt_str(part_devt(part), devt_buf), (unsigned long long)part->nr_sects >> 1, disk_name(disk, part->partno, name_buf)); + if (is_part0) { + if (disk->driverfs_dev != NULL && + disk->driverfs_dev->driver != NULL) + printk(" driver: %s\n", + disk->driverfs_dev->driver->name); + else + printk(" (driver?)\n"); + } else + printk("\n"); + } disk_part_iter_exit(&piter); } class_dev_iter_exit(&iter); @@ -611,7 +686,7 @@ static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos) struct class_dev_iter *iter; struct device *dev; - iter = kmalloc(GFP_KERNEL, sizeof(*iter)); + iter = kmalloc(sizeof(*iter), GFP_KERNEL); if (!iter) return ERR_PTR(-ENOMEM); @@ -654,7 +729,7 @@ static void *show_partition_start(struct seq_file *seqf, loff_t *pos) static void *p; p = disk_seqf_start(seqf, pos); - if (!IS_ERR(p) && p) + if (!IS_ERR(p) && p && !*pos) seq_puts(seqf, "major minor #blocks name\n\n"); return p; } @@ -674,12 +749,7 @@ static int show_partition(struct seq_file *seqf, void *v) return 0; /* show the full disk and all non-0 size partitions of it */ - seq_printf(seqf, "%4d %7d %10llu %s\n", - MAJOR(disk_devt(sgp)), MINOR(disk_devt(sgp)), - (unsigned long long)get_capacity(sgp) >> 1, - disk_name(sgp, 0, buf)); - - disk_part_iter_init(&piter, sgp, 0); + disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0); while ((part = disk_part_iter_next(&piter))) seq_printf(seqf, "%4d %7d %10llu %s\n", MAJOR(part_devt(part)), MINOR(part_devt(part)), @@ -690,12 +760,24 @@ static int show_partition(struct seq_file *seqf, void *v) return 0; } -const struct seq_operations partitions_op = { +static const struct seq_operations partitions_op = { .start = show_partition_start, .next = disk_seqf_next, .stop = disk_seqf_stop, .show = show_partition }; + +static int partitions_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &partitions_op); +} + +static const struct file_operations proc_partitions_operations = { + .open = partitions_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; #endif @@ -718,6 +800,8 @@ static int __init genhd_device_init(void) bdev_map = kobj_map_init(base_probe, &block_class_lock); blk_dev_init(); + register_blkdev(BLOCK_EXT_MAJOR, "blkext"); + #ifndef CONFIG_SYSFS_DEPRECATED /* create top-level block dir */ block_depr = kobject_create_and_add("block", NULL); @@ -768,44 +852,22 @@ static ssize_t disk_capability_show(struct device *dev, return sprintf(buf, "%x\n", disk->flags); } -static ssize_t disk_stat_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct gendisk *disk = dev_to_disk(dev); - int cpu; - - cpu = disk_stat_lock(); - disk_round_stats(cpu, disk); - disk_stat_unlock(); - return sprintf(buf, - "%8lu %8lu %8llu %8u " - "%8lu %8lu %8llu %8u " - "%8u %8u %8u" - "\n", - disk_stat_read(disk, ios[READ]), - disk_stat_read(disk, merges[READ]), - (unsigned long long)disk_stat_read(disk, sectors[READ]), - jiffies_to_msecs(disk_stat_read(disk, ticks[READ])), - disk_stat_read(disk, ios[WRITE]), - disk_stat_read(disk, merges[WRITE]), - (unsigned long long)disk_stat_read(disk, sectors[WRITE]), - jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])), - disk->in_flight, - jiffies_to_msecs(disk_stat_read(disk, io_ticks)), - jiffies_to_msecs(disk_stat_read(disk, time_in_queue))); -} - static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL); static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL); static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL); static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL); static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL); static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL); -static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL); +static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL); #ifdef CONFIG_FAIL_MAKE_REQUEST static struct device_attribute dev_attr_fail = __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store); #endif +#ifdef CONFIG_FAIL_IO_TIMEOUT +static struct device_attribute dev_attr_fail_timeout = + __ATTR(io-timeout-fail, S_IRUGO|S_IWUSR, part_timeout_show, + part_timeout_store); +#endif static struct attribute *disk_attrs[] = { &dev_attr_range.attr, @@ -818,6 +880,9 @@ static struct attribute *disk_attrs[] = { #ifdef CONFIG_FAIL_MAKE_REQUEST &dev_attr_fail.attr, #endif +#ifdef CONFIG_FAIL_IO_TIMEOUT + &dev_attr_fail_timeout.attr, +#endif NULL }; @@ -830,13 +895,90 @@ static struct attribute_group *disk_attr_groups[] = { NULL }; +static void disk_free_ptbl_rcu_cb(struct rcu_head *head) +{ + struct disk_part_tbl *ptbl = + container_of(head, struct disk_part_tbl, rcu_head); + + kfree(ptbl); +} + +/** + * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way + * @disk: disk to replace part_tbl for + * @new_ptbl: new part_tbl to install + * + * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The + * original ptbl is freed using RCU callback. + * + * LOCKING: + * Matching bd_mutx locked. + */ +static void disk_replace_part_tbl(struct gendisk *disk, + struct disk_part_tbl *new_ptbl) +{ + struct disk_part_tbl *old_ptbl = disk->part_tbl; + + rcu_assign_pointer(disk->part_tbl, new_ptbl); + + if (old_ptbl) { + rcu_assign_pointer(old_ptbl->last_lookup, NULL); + call_rcu(&old_ptbl->rcu_head, disk_free_ptbl_rcu_cb); + } +} + +/** + * disk_expand_part_tbl - expand disk->part_tbl + * @disk: disk to expand part_tbl for + * @partno: expand such that this partno can fit in + * + * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl + * uses RCU to allow unlocked dereferencing for stats and other stuff. + * + * LOCKING: + * Matching bd_mutex locked, might sleep. + * + * RETURNS: + * 0 on success, -errno on failure. + */ +int disk_expand_part_tbl(struct gendisk *disk, int partno) +{ + struct disk_part_tbl *old_ptbl = disk->part_tbl; + struct disk_part_tbl *new_ptbl; + int len = old_ptbl ? old_ptbl->len : 0; + int target = partno + 1; + size_t size; + int i; + + /* disk_max_parts() is zero during initialization, ignore if so */ + if (disk_max_parts(disk) && target > disk_max_parts(disk)) + return -EINVAL; + + if (target <= len) + return 0; + + size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]); + new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id); + if (!new_ptbl) + return -ENOMEM; + + INIT_RCU_HEAD(&new_ptbl->rcu_head); + new_ptbl->len = target; + + for (i = 0; i < len; i++) + rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]); + + disk_replace_part_tbl(disk, new_ptbl); + return 0; +} + static void disk_release(struct device *dev) { struct gendisk *disk = dev_to_disk(dev); kfree(disk->random); - kfree(disk->__part); - free_disk_stats(disk); + disk_replace_part_tbl(disk, NULL); + free_part_stats(&disk->part0); kfree(disk); } struct class block_class = { @@ -873,28 +1015,11 @@ static int diskstats_show(struct seq_file *seqf, void *v) "\n\n"); */ - cpu = disk_stat_lock(); - disk_round_stats(cpu, gp); - disk_stat_unlock(); - seq_printf(seqf, "%4d %7d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n", - 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])), - disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]), - (unsigned long long)disk_stat_read(gp, sectors[1]), - jiffies_to_msecs(disk_stat_read(gp, ticks[1])), - gp->in_flight, - jiffies_to_msecs(disk_stat_read(gp, io_ticks)), - jiffies_to_msecs(disk_stat_read(gp, time_in_queue))); - - /* now show all non-0 size partitions of it */ - disk_part_iter_init(&piter, gp, 0); + disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0); while ((hd = disk_part_iter_next(&piter))) { - cpu = disk_stat_lock(); + cpu = part_stat_lock(); part_round_stats(cpu, hd); - disk_stat_unlock(); + part_stat_unlock(); seq_printf(seqf, "%4d %7d %s %lu %lu %llu " "%u %lu %lu %llu %u %u %u %u\n", MAJOR(part_devt(hd)), MINOR(part_devt(hd)), @@ -917,12 +1042,32 @@ static int diskstats_show(struct seq_file *seqf, void *v) return 0; } -const struct seq_operations diskstats_op = { +static const struct seq_operations diskstats_op = { .start = disk_seqf_start, .next = disk_seqf_next, .stop = disk_seqf_stop, .show = diskstats_show }; + +static int diskstats_open(struct inode *inode, struct file *file) +{ + return seq_open(file, &diskstats_op); +} + +static const struct file_operations proc_diskstats_operations = { + .open = diskstats_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release, +}; + +static int __init proc_genhd_init(void) +{ + proc_create("diskstats", 0, NULL, &proc_diskstats_operations); + proc_create("partitions", 0, NULL, &proc_partitions_operations); + return 0; +} +module_init(proc_genhd_init); #endif /* CONFIG_PROC_FS */ static void media_change_notify_thread(struct work_struct *work) @@ -959,11 +1104,19 @@ dev_t blk_lookup_devt(const char *name, int partno) struct gendisk *disk = dev_to_disk(dev); struct hd_struct *part; - if (strcmp(dev->bus_id, name)) + if (strcmp(dev_name(dev), name)) continue; + if (partno < disk->minors) { + /* We need to return the right devno, even + * if the partition doesn't exist yet. + */ + devt = MKDEV(MAJOR(dev->devt), + MINOR(dev->devt) + partno); + break; + } part = disk_get_part(disk, partno); - if (part && (part->nr_sects || partno == 0)) { + if (part) { devt = part_devt(part); disk_put_part(part); break; @@ -979,43 +1132,28 @@ struct gendisk *alloc_disk(int minors) { return alloc_disk_node(minors, -1); } +EXPORT_SYMBOL(alloc_disk); struct gendisk *alloc_disk_node(int minors, int node_id) { - return alloc_disk_ext_node(minors, 0, node_id); -} - -struct gendisk *alloc_disk_ext(int minors, int ext_minors) -{ - return alloc_disk_ext_node(minors, ext_minors, -1); -} - -struct gendisk *alloc_disk_ext_node(int minors, int ext_minors, int node_id) -{ struct gendisk *disk; disk = kmalloc_node(sizeof(struct gendisk), GFP_KERNEL | __GFP_ZERO, node_id); if (disk) { - int tot_minors = minors + ext_minors; - int size = tot_minors * sizeof(struct hd_struct *); - - if (!init_disk_stats(disk)) { + if (!init_part_stats(&disk->part0)) { kfree(disk); return NULL; } - - disk->__part = kmalloc_node(size, GFP_KERNEL | __GFP_ZERO, - node_id); - if (!disk->__part) { - free_disk_stats(disk); + disk->node_id = node_id; + if (disk_expand_part_tbl(disk, 0)) { + free_part_stats(&disk->part0); kfree(disk); return NULL; } - disk->__part[0] = &disk->part0; + disk->part_tbl->part[0] = &disk->part0; disk->minors = minors; - disk->ext_minors = ext_minors; rand_initialize_disk(disk); disk_to_dev(disk)->class = &block_class; disk_to_dev(disk)->type = &disk_type; @@ -1025,11 +1163,7 @@ struct gendisk *alloc_disk_ext_node(int minors, int ext_minors, int node_id) } return disk; } - -EXPORT_SYMBOL(alloc_disk); EXPORT_SYMBOL(alloc_disk_node); -EXPORT_SYMBOL(alloc_disk_ext); -EXPORT_SYMBOL(alloc_disk_ext_node); struct kobject *get_disk(struct gendisk *disk) {