X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=drivers%2Fblock%2Floop.c;h=bd112c8c7bcde9b3efdbceadc6fc89d65f6c9ea0;hb=82dca611bb516ec5fb7d04077733d6a4b70f52d1;hp=87d84e7d54321e08d1a451905a759241f055ca8e;hpb=fd5821404e6823997666d668f62c76eae228abc9;p=safe%2Fjmp%2Flinux-2.6 diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 87d84e7..bd112c8 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -29,7 +29,7 @@ * * Maximum number of loop devices when compiled-in now selectable by passing * max_loop=<1-255> to the kernel on boot. - * Erik I. Bolsø, , Oct 31, 1999 + * Erik I. Bolsø, , Oct 31, 1999 * * Completely rewrite request handling to be make_request_fn style and * non blocking, pushing work to a helper thread. Lots of fixes from @@ -40,8 +40,7 @@ * Heinz Mauelshagen , Feb 2002 * * Support for falling back on the write file operation when the address space - * operations prepare_write and/or commit_write are not available on the - * backing filesystem. + * operations write_begin is not available on the backing filesystem. * Anton Altaparmakov, 16 Feb 2005 * * Still To Fix: @@ -62,25 +61,28 @@ #include #include #include -#include #include #include #include #include #include +#include #include #include /* for invalidate_bdev() */ #include #include #include #include -#include +#include #include static LIST_HEAD(loop_devices); static DEFINE_MUTEX(loop_devices_mutex); +static int max_part; +static int part_shift; + /* * Transfer functions */ @@ -203,14 +205,13 @@ lo_do_transfer(struct loop_device *lo, int cmd, * do_lo_send_aops - helper for writing data to a loop device * * This is the fast version for backing filesystems which implement the address - * space operations prepare_write and commit_write. + * space operations write_begin and write_end. */ static int do_lo_send_aops(struct loop_device *lo, struct bio_vec *bvec, - int bsize, loff_t pos, struct page *page) + loff_t pos, struct page *unused) { struct file *file = lo->lo_backing_file; /* kudos to NFsckingS */ struct address_space *mapping = file->f_mapping; - const struct address_space_operations *aops = mapping->a_ops; pgoff_t index; unsigned offset, bv_offs; int len, ret; @@ -222,63 +223,45 @@ static int do_lo_send_aops(struct loop_device *lo, struct bio_vec *bvec, len = bvec->bv_len; while (len > 0) { sector_t IV; - unsigned size; + unsigned size, copied; int transfer_result; + struct page *page; + void *fsdata; IV = ((sector_t)index << (PAGE_CACHE_SHIFT - 9))+(offset >> 9); size = PAGE_CACHE_SIZE - offset; if (size > len) size = len; - page = grab_cache_page(mapping, index); - if (unlikely(!page)) + + ret = pagecache_write_begin(file, mapping, pos, size, 0, + &page, &fsdata); + if (ret) goto fail; - ret = aops->prepare_write(file, page, offset, - offset + size); - if (unlikely(ret)) { - if (ret == AOP_TRUNCATED_PAGE) { - page_cache_release(page); - continue; - } - goto unlock; - } + transfer_result = lo_do_transfer(lo, WRITE, page, offset, bvec->bv_page, bv_offs, size, IV); - if (unlikely(transfer_result)) { - /* - * The transfer failed, but we still write the data to - * keep prepare/commit calls balanced. - */ - printk(KERN_ERR "loop: transfer error block %llu\n", - (unsigned long long)index); - zero_user_page(page, offset, size, KM_USER0); - } - flush_dcache_page(page); - ret = aops->commit_write(file, page, offset, - offset + size); - if (unlikely(ret)) { - if (ret == AOP_TRUNCATED_PAGE) { - page_cache_release(page); - continue; - } - goto unlock; - } + copied = size; + if (unlikely(transfer_result)) + copied = 0; + + ret = pagecache_write_end(file, mapping, pos, size, copied, + page, fsdata); + if (ret < 0 || ret != copied) + goto fail; + if (unlikely(transfer_result)) - goto unlock; - bv_offs += size; - len -= size; + goto fail; + + bv_offs += copied; + len -= copied; offset = 0; index++; - pos += size; - unlock_page(page); - page_cache_release(page); + pos += copied; } ret = 0; out: mutex_unlock(&mapping->host->i_mutex); return ret; -unlock: - unlock_page(page); - page_cache_release(page); fail: ret = -1; goto out; @@ -312,12 +295,12 @@ static int __do_lo_send_write(struct file *file, * do_lo_send_direct_write - helper for writing data to a loop device * * This is the fast, non-transforming version for backing filesystems which do - * not implement the address space operations prepare_write and commit_write. + * not implement the address space operations write_begin and write_end. * It uses the write file operation which should be present on all writeable * filesystems. */ static int do_lo_send_direct_write(struct loop_device *lo, - struct bio_vec *bvec, int bsize, loff_t pos, struct page *page) + struct bio_vec *bvec, loff_t pos, struct page *page) { ssize_t bw = __do_lo_send_write(lo->lo_backing_file, kmap(bvec->bv_page) + bvec->bv_offset, @@ -331,7 +314,7 @@ static int do_lo_send_direct_write(struct loop_device *lo, * do_lo_send_write - helper for writing data to a loop device * * This is the slow, transforming version for filesystems which do not - * implement the address space operations prepare_write and commit_write. It + * implement the address space operations write_begin and write_end. It * uses the write file operation which should be present on all writeable * filesystems. * @@ -341,7 +324,7 @@ static int do_lo_send_direct_write(struct loop_device *lo, * destination pages of the backing file. */ static int do_lo_send_write(struct loop_device *lo, struct bio_vec *bvec, - int bsize, loff_t pos, struct page *page) + loff_t pos, struct page *page) { int ret = lo_do_transfer(lo, WRITE, page, 0, bvec->bv_page, bvec->bv_offset, bvec->bv_len, pos >> 9); @@ -356,10 +339,9 @@ static int do_lo_send_write(struct loop_device *lo, struct bio_vec *bvec, return ret; } -static int lo_send(struct loop_device *lo, struct bio *bio, int bsize, - loff_t pos) +static int lo_send(struct loop_device *lo, struct bio *bio, loff_t pos) { - int (*do_lo_send)(struct loop_device *, struct bio_vec *, int, loff_t, + int (*do_lo_send)(struct loop_device *, struct bio_vec *, loff_t, struct page *page); struct bio_vec *bvec; struct page *page = NULL; @@ -377,7 +359,7 @@ static int lo_send(struct loop_device *lo, struct bio *bio, int bsize, } } bio_for_each_segment(bvec, bio, i) { - ret = do_lo_send(lo, bvec, bsize, pos, page); + ret = do_lo_send(lo, bvec, pos, page); if (ret < 0) break; pos += bvec->bv_len; @@ -409,10 +391,9 @@ lo_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, struct loop_device *lo = p->lo; struct page *page = buf->page; sector_t IV; - size_t size; - int ret; + int size, ret; - ret = buf->ops->pin(pipe, buf); + ret = buf->ops->confirm(pipe, buf); if (unlikely(ret)) return ret; @@ -492,10 +473,35 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio) int ret; pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset; - if (bio_rw(bio) == WRITE) - ret = lo_send(lo, bio, lo->lo_blocksize, pos); - else + + if (bio_rw(bio) == WRITE) { + bool barrier = bio_rw_flagged(bio, BIO_RW_BARRIER); + struct file *file = lo->lo_backing_file; + + if (barrier) { + if (unlikely(!file->f_op->fsync)) { + ret = -EOPNOTSUPP; + goto out; + } + + ret = vfs_fsync(file, file->f_path.dentry, 0); + if (unlikely(ret)) { + ret = -EIO; + goto out; + } + } + + ret = lo_send(lo, bio, pos); + + if (barrier && !ret) { + ret = vfs_fsync(file, file->f_path.dentry, 0); + if (unlikely(ret)) + ret = -EIO; + } + } else ret = lo_receive(lo, bio, lo->lo_blocksize, pos); + +out: return ret; } @@ -504,11 +510,7 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio) */ static void loop_add_bio(struct loop_device *lo, struct bio *bio) { - if (lo->lo_biotail) { - lo->lo_biotail->bi_next = bio; - lo->lo_biotail = bio; - } else - lo->lo_bio = lo->lo_biotail = bio; + bio_list_add(&lo->lo_bio_list, bio); } /* @@ -516,19 +518,10 @@ static void loop_add_bio(struct loop_device *lo, struct bio *bio) */ static struct bio *loop_get_bio(struct loop_device *lo) { - struct bio *bio; - - if ((bio = lo->lo_bio)) { - if (bio == lo->lo_biotail) - lo->lo_biotail = NULL; - lo->lo_bio = bio->bi_next; - bio->bi_next = NULL; - } - - return bio; + return bio_list_pop(&lo->lo_bio_list); } -static int loop_make_request(request_queue_t *q, struct bio *old_bio) +static int loop_make_request(struct request_queue *q, struct bio *old_bio) { struct loop_device *lo = q->queuedata; int rw = bio_rw(old_bio); @@ -550,18 +543,18 @@ static int loop_make_request(request_queue_t *q, struct bio *old_bio) out: spin_unlock_irq(&lo->lo_lock); - bio_io_error(old_bio, old_bio->bi_size); + bio_io_error(old_bio); return 0; } /* * kick off io on the underlying address space */ -static void loop_unplug(request_queue_t *q) +static void loop_unplug(struct request_queue *q) { struct loop_device *lo = q->queuedata; - clear_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags); + queue_flag_clear_unlocked(QUEUE_FLAG_PLUGGED, q); blk_run_address_space(lo->lo_backing_file->f_mapping); } @@ -579,7 +572,7 @@ static inline void loop_handle_bio(struct loop_device *lo, struct bio *bio) bio_put(bio); } else { int ret = do_bio_filebacked(lo, bio); - bio_endio(bio, bio->bi_size, ret); + bio_endio(bio, ret); } } @@ -600,21 +593,15 @@ static int loop_thread(void *data) struct loop_device *lo = data; struct bio *bio; - /* - * loop can be used in an encrypted device, - * hence, it mustn't be stopped at all - * because it could be indirectly used during suspension - */ - current->flags |= PF_NOFREEZE; - set_user_nice(current, -20); - while (!kthread_should_stop() || lo->lo_bio) { + while (!kthread_should_stop() || !bio_list_empty(&lo->lo_bio_list)) { wait_event_interruptible(lo->lo_event, - lo->lo_bio || kthread_should_stop()); + !bio_list_empty(&lo->lo_bio_list) || + kthread_should_stop()); - if (!lo->lo_bio) + if (bio_list_empty(&lo->lo_bio_list)) continue; spin_lock_irq(&lo->lo_lock); bio = loop_get_bio(lo); @@ -635,7 +622,7 @@ static int loop_thread(void *data) static int loop_switch(struct loop_device *lo, struct file *file) { struct switch_request w; - struct bio *bio = bio_alloc(GFP_KERNEL, 1); + struct bio *bio = bio_alloc(GFP_KERNEL, 0); if (!bio) return -ENOMEM; init_completion(&w.wait); @@ -648,20 +635,38 @@ static int loop_switch(struct loop_device *lo, struct file *file) } /* + * Helper to flush the IOs in loop, but keeping loop thread running + */ +static int loop_flush(struct loop_device *lo) +{ + /* loop not yet configured, no running thread, nothing to flush */ + if (!lo->lo_thread) + return 0; + + return loop_switch(lo, NULL); +} + +/* * Do the actual switch; called from the BIO completion routine */ static void do_loop_switch(struct loop_device *lo, struct switch_request *p) { struct file *file = p->file; struct file *old_file = lo->lo_backing_file; - struct address_space *mapping = file->f_mapping; + struct address_space *mapping; + + /* if no new file, only flush of queued bios requested */ + if (!file) + goto out; + mapping = file->f_mapping; mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); lo->lo_backing_file = file; lo->lo_blocksize = S_ISBLK(mapping->host->i_mode) ? mapping->host->i_bdev->bd_block_size : PAGE_SIZE; lo->old_gfp_mask = mapping_gfp_mask(mapping); mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); +out: complete(&p->wait); } @@ -674,8 +679,8 @@ static void do_loop_switch(struct loop_device *lo, struct switch_request *p) * This can only work if the loop device is used read-only, and if the * new backing store is the same size and type as the old backing store. */ -static int loop_change_fd(struct loop_device *lo, struct file *lo_file, - struct block_device *bdev, unsigned int arg) +static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, + unsigned int arg) { struct file *file, *old_file; struct inode *inode; @@ -703,10 +708,6 @@ static int loop_change_fd(struct loop_device *lo, struct file *lo_file, if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) goto out_putf; - /* new backing store needs to support loop (eg splice_read) */ - if (!inode->i_fop->splice_read) - goto out_putf; - /* size of the new backing store needs to be the same */ if (get_loop_size(lo, file) != get_loop_size(lo, old_file)) goto out_putf; @@ -717,6 +718,8 @@ static int loop_change_fd(struct loop_device *lo, struct file *lo_file, goto out_putf; fput(old_file); + if (max_part > 0) + ioctl_by_bdev(bdev, BLKRRPART, 0); return 0; out_putf: @@ -732,7 +735,7 @@ static inline int is_loop_device(struct file *file) return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == LOOP_MAJOR; } -static int loop_set_fd(struct loop_device *lo, struct file *lo_file, +static int loop_set_fd(struct loop_device *lo, fmode_t mode, struct block_device *bdev, unsigned int arg) { struct file *file, *f; @@ -760,7 +763,7 @@ static int loop_set_fd(struct loop_device *lo, struct file *lo_file, while (is_loop_device(f)) { struct loop_device *l; - if (f->f_mapping->host->i_rdev == lo_file->f_mapping->host->i_rdev) + if (f->f_mapping->host->i_bdev == bdev) goto out_putf; l = f->f_mapping->host->i_bdev->bd_disk->private_data; @@ -780,13 +783,8 @@ static int loop_set_fd(struct loop_device *lo, struct file *lo_file, error = -EINVAL; if (S_ISREG(inode->i_mode) || S_ISBLK(inode->i_mode)) { const struct address_space_operations *aops = mapping->a_ops; - /* - * If we can't read - sorry. If we only can't write - well, - * it's going to be read-only. - */ - if (!file->f_op->splice_read) - goto out_putf; - if (aops->prepare_write && aops->commit_write) + + if (aops->write_begin) lo_flags |= LO_FLAGS_USE_AOPS; if (!(lo_flags & LO_FLAGS_USE_AOPS) && !file->f_op->write) lo_flags |= LO_FLAGS_READ_ONLY; @@ -806,7 +804,7 @@ static int loop_set_fd(struct loop_device *lo, struct file *lo_file, goto out_putf; } - if (!(lo_file->f_mode & FMODE_WRITE)) + if (!(mode & FMODE_WRITE)) lo_flags |= LO_FLAGS_READ_ONLY; set_device_ro(bdev, (lo_flags & LO_FLAGS_READ_ONLY) != 0); @@ -821,7 +819,7 @@ static int loop_set_fd(struct loop_device *lo, struct file *lo_file, lo->old_gfp_mask = mapping_gfp_mask(mapping); mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); - lo->lo_bio = lo->lo_biotail = NULL; + bio_list_init(&lo->lo_bio_list); /* * set queue make_request_fn, and add limits based on lower level @@ -831,6 +829,9 @@ static int loop_set_fd(struct loop_device *lo, struct file *lo_file, lo->lo_queue->queuedata = lo; lo->lo_queue->unplug_fn = loop_unplug; + if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync) + blk_queue_ordered(lo->lo_queue, QUEUE_ORDERED_DRAIN, NULL); + set_capacity(lo->lo_disk, size); bd_set_size(bdev, size << 9); @@ -844,6 +845,8 @@ static int loop_set_fd(struct loop_device *lo, struct file *lo_file, } lo->lo_state = Lo_bound; wake_up_process(lo->lo_thread); + if (max_part > 0) + ioctl_by_bdev(bdev, BLKRRPART, 0); return 0; out_clr: @@ -921,6 +924,7 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev) kthread_stop(lo->lo_thread); + lo->lo_queue->unplug_fn = NULL; lo->lo_backing_file = NULL; loop_release_xfer(lo); @@ -936,14 +940,25 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev) memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE); memset(lo->lo_crypt_name, 0, LO_NAME_SIZE); memset(lo->lo_file_name, 0, LO_NAME_SIZE); - invalidate_bdev(bdev); + if (bdev) + invalidate_bdev(bdev); set_capacity(lo->lo_disk, 0); - bd_set_size(bdev, 0); + if (bdev) + bd_set_size(bdev, 0); mapping_set_gfp_mask(filp->f_mapping, gfp); lo->lo_state = Lo_unbound; - fput(filp); /* This is safe: open() is still holding a reference. */ module_put(THIS_MODULE); + if (max_part > 0 && bdev) + ioctl_by_bdev(bdev, BLKRRPART, 0); + mutex_unlock(&lo->lo_ctl_mutex); + /* + * Need not hold lo_ctl_mutex to fput backing file. + * Calling fput holding lo_ctl_mutex triggers a circular + * lock dependency possibility warning as fput can take + * bd_mutex which is usually taken before lo_ctl_mutex. + */ + fput(filp); return 0; } @@ -952,8 +967,10 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) { int err; struct loop_func_table *xfer; + uid_t uid = current_uid(); - if (lo->lo_encrypt_key_size && lo->lo_key_owner != current->uid && + if (lo->lo_encrypt_key_size && + lo->lo_key_owner != uid && !capable(CAP_SYS_ADMIN)) return -EPERM; if (lo->lo_state != Lo_bound) @@ -998,13 +1015,17 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) lo->transfer = xfer->transfer; lo->ioctl = xfer->ioctl; + if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) != + (info->lo_flags & LO_FLAGS_AUTOCLEAR)) + lo->lo_flags ^= LO_FLAGS_AUTOCLEAR; + lo->lo_encrypt_key_size = info->lo_encrypt_key_size; lo->lo_init[0] = info->lo_init[0]; lo->lo_init[1] = info->lo_init[1]; if (info->lo_encrypt_key_size) { memcpy(lo->lo_encrypt_key, info->lo_encrypt_key, info->lo_encrypt_key_size); - lo->lo_key_owner = current->uid; + lo->lo_key_owner = uid; } return 0; @@ -1149,22 +1170,49 @@ loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) { return err; } -static int lo_ioctl(struct inode * inode, struct file * file, +static int loop_set_capacity(struct loop_device *lo, struct block_device *bdev) +{ + int err; + sector_t sec; + loff_t sz; + + err = -ENXIO; + if (unlikely(lo->lo_state != Lo_bound)) + goto out; + err = figure_loop_size(lo); + if (unlikely(err)) + goto out; + sec = get_capacity(lo->lo_disk); + /* the width of sector_t may be narrow for bit-shift */ + sz = sec; + sz <<= 9; + mutex_lock(&bdev->bd_mutex); + bd_set_size(bdev, sz); + mutex_unlock(&bdev->bd_mutex); + + out: + return err; +} + +static int lo_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg) { - struct loop_device *lo = inode->i_bdev->bd_disk->private_data; + struct loop_device *lo = bdev->bd_disk->private_data; int err; - mutex_lock(&lo->lo_ctl_mutex); + mutex_lock_nested(&lo->lo_ctl_mutex, 1); switch (cmd) { case LOOP_SET_FD: - err = loop_set_fd(lo, file, inode->i_bdev, arg); + err = loop_set_fd(lo, mode, bdev, arg); break; case LOOP_CHANGE_FD: - err = loop_change_fd(lo, file, inode->i_bdev, arg); + err = loop_change_fd(lo, bdev, arg); break; case LOOP_CLR_FD: - err = loop_clr_fd(lo, inode->i_bdev); + /* loop_clr_fd would have unlocked lo_ctl_mutex on success */ + err = loop_clr_fd(lo, bdev); + if (!err) + goto out_unlocked; break; case LOOP_SET_STATUS: err = loop_set_status_old(lo, (struct loop_info __user *) arg); @@ -1178,10 +1226,17 @@ static int lo_ioctl(struct inode * inode, struct file * file, case LOOP_GET_STATUS64: err = loop_get_status64(lo, (struct loop_info64 __user *) arg); break; + case LOOP_SET_CAPACITY: + err = -EPERM; + if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) + err = loop_set_capacity(lo, bdev); + break; default: err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; } mutex_unlock(&lo->lo_ctl_mutex); + +out_unlocked: return err; } @@ -1304,13 +1359,12 @@ loop_get_status_compat(struct loop_device *lo, return err; } -static long lo_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode, + unsigned int cmd, unsigned long arg) { - struct inode *inode = file->f_path.dentry->d_inode; - struct loop_device *lo = inode->i_bdev->bd_disk->private_data; + struct loop_device *lo = bdev->bd_disk->private_data; int err; - lock_kernel(); switch(cmd) { case LOOP_SET_STATUS: mutex_lock(&lo->lo_ctl_mutex); @@ -1324,26 +1378,26 @@ static long lo_compat_ioctl(struct file *file, unsigned int cmd, unsigned long a lo, (struct compat_loop_info __user *) arg); mutex_unlock(&lo->lo_ctl_mutex); break; + case LOOP_SET_CAPACITY: case LOOP_CLR_FD: case LOOP_GET_STATUS64: case LOOP_SET_STATUS64: arg = (unsigned long) compat_ptr(arg); case LOOP_SET_FD: case LOOP_CHANGE_FD: - err = lo_ioctl(inode, file, cmd, arg); + err = lo_ioctl(bdev, mode, cmd, arg); break; default: err = -ENOIOCTLCMD; break; } - unlock_kernel(); return err; } #endif -static int lo_open(struct inode *inode, struct file *file) +static int lo_open(struct block_device *bdev, fmode_t mode) { - struct loop_device *lo = inode->i_bdev->bd_disk->private_data; + struct loop_device *lo = bdev->bd_disk->private_data; mutex_lock(&lo->lo_ctl_mutex); lo->lo_refcnt++; @@ -1352,18 +1406,39 @@ static int lo_open(struct inode *inode, struct file *file) return 0; } -static int lo_release(struct inode *inode, struct file *file) +static int lo_release(struct gendisk *disk, fmode_t mode) { - struct loop_device *lo = inode->i_bdev->bd_disk->private_data; + struct loop_device *lo = disk->private_data; + int err; mutex_lock(&lo->lo_ctl_mutex); - --lo->lo_refcnt; - mutex_unlock(&lo->lo_ctl_mutex); + if (--lo->lo_refcnt) + goto out; + + if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) { + /* + * In autoclear mode, stop the loop thread + * and remove configuration after last close. + */ + err = loop_clr_fd(lo, NULL); + if (!err) + goto out_unlocked; + } else { + /* + * Otherwise keep thread (if running) and config, + * but flush possible ongoing bios in thread. + */ + loop_flush(lo); + } + +out: + mutex_unlock(&lo->lo_ctl_mutex); +out_unlocked: return 0; } -static struct block_device_operations lo_fops = { +static const struct block_device_operations lo_fops = { .owner = THIS_MODULE, .open = lo_open, .release = lo_release, @@ -1379,6 +1454,8 @@ static struct block_device_operations lo_fops = { static int max_loop; module_param(max_loop, int, 0); MODULE_PARM_DESC(max_loop, "Maximum number of loop devices"); +module_param(max_part, int, 0); +MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device"); MODULE_LICENSE("GPL"); MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR); @@ -1431,7 +1508,7 @@ static struct loop_device *loop_alloc(int i) if (!lo->lo_queue) goto out_free_dev; - disk = lo->lo_disk = alloc_disk(1); + disk = lo->lo_disk = alloc_disk(1 << part_shift); if (!disk) goto out_free_queue; @@ -1441,7 +1518,7 @@ static struct loop_device *loop_alloc(int i) init_waitqueue_head(&lo->lo_event); spin_lock_init(&lo->lo_lock); disk->major = LOOP_MAJOR; - disk->first_minor = i; + disk->first_minor = i << part_shift; disk->fops = &lo_fops; disk->private_data = lo; disk->queue = lo->lo_queue; @@ -1521,7 +1598,12 @@ static int __init loop_init(void) * themselves and have kernel automatically instantiate actual * device on-demand. */ - if (max_loop > 1UL << MINORBITS) + + part_shift = 0; + if (max_part > 0) + part_shift = fls(max_part); + + if (max_loop > 1UL << (MINORBITS - part_shift)) return -EINVAL; if (max_loop) { @@ -1529,7 +1611,7 @@ static int __init loop_init(void) range = max_loop; } else { nr = 8; - range = 1UL << MINORBITS; + range = 1UL << (MINORBITS - part_shift); } if (register_blkdev(LOOP_MAJOR, "loop")) @@ -1568,14 +1650,13 @@ static void __exit loop_exit(void) unsigned long range; struct loop_device *lo, *next; - range = max_loop ? max_loop : 1UL << MINORBITS; + range = max_loop ? max_loop : 1UL << (MINORBITS - part_shift); list_for_each_entry_safe(lo, next, &loop_devices, lo_list) loop_del_one(lo); blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range); - if (unregister_blkdev(LOOP_MAJOR, "loop")) - printk(KERN_WARNING "loop: cannot unregister blkdev\n"); + unregister_blkdev(LOOP_MAJOR, "loop"); } module_init(loop_init);