--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
+ * vim:expandtab:shiftwidth=8:tabstop=8:
+ *
+ * Lustre virtual block device emulator.
+ *
+ * Copyright (c) 2001-2003 Cluster File Systems, Inc.
+ *
+ * This file is part of Lustre, http://www.lustre.org.
+ *
+ * Lustre is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Lustre is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Lustre; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/*
+ * linux/drivers/block/loop.c
+ *
+ * Written by Theodore Ts'o, 3/29/93
+ *
+ * Copyright 1993 by Theodore Ts'o. Redistribution of this file is
+ * permitted under the GNU General Public License.
+ *
+ * DES encryption plus some minor changes by Werner Almesberger, 30-MAY-1993
+ * more DES encryption plus IDEA encryption by Nicholas J. Leon, June 20, 1996
+ *
+ * Modularized and updated for 1.1.16 kernel - Mitch Dsouza 28th May 1994
+ * Adapted for 1.3.59 kernel - Andries Brouwer, 1 Feb 1996
+ *
+ * Fixed do_loop_request() re-entrancy - Vincent.Renardias@waw.com Mar 20, 1997
+ *
+ * Added devfs support - Richard Gooch <rgooch@atnf.csiro.au> 16-Jan-1998
+ *
+ * Handle sparse backing files correctly - Kenn Humborg, Jun 28, 1998
+ *
+ * Loadable modules and other fixes by AK, 1998
+ *
+ * Make real block number available to downstream transfer functions, enables
+ * CBC (and relatives) mode encryption requiring unique IVs per data block.
+ * Reed H. Petty, rhp@draper.net
+ *
+ * Maximum number of loop devices now dynamic via max_loop module parameter.
+ * Russell Kroll <rkroll@exploits.org> 19990701
+ *
+ * Maximum number of loop devices when compiled-in now selectable by passing
+ * max_loop=<1-255> to the kernel on boot.
+ * Erik I. Bols?, <eriki@himolde.no>, 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
+ * Al Viro too.
+ * Jens Axboe <axboe@suse.de>, Nov 2000
+ *
+ * Support up to 256 loop devices
+ * Heinz Mauelshagen <mge@sistina.com>, 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.
+ * Anton Altaparmakov, 16 Feb 2005
+ *
+ * Still To Fix:
+ * - Advisory locking is ignored here.
+ * - Should use an own CAP_* category instead of CAP_SYS_ADMIN
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/stat.h>
+#include <linux/errno.h>
+#include <linux/major.h>
+#include <linux/wait.h>
+#include <linux/blkdev.h>
+#include <linux/blkpg.h>
+#include <linux/init.h>
+#include <linux/smp_lock.h>
+#include <linux/swap.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+#include <linux/writeback.h>
+#include <linux/buffer_head.h> /* for invalidate_bdev() */
+#include <linux/completion.h>
+#include <linux/highmem.h>
+#include <linux/gfp.h>
+#include <linux/swap.h>
+#include <linux/pagevec.h>
+
+#include <asm/uaccess.h>
+
+#include <lustre_lib.h>
+#include <lustre_lite.h>
+#include "llite_internal.h"
+
+#define LLOOP_MAX_SEGMENTS PTLRPC_MAX_BRW_PAGES
+
+/* Possible states of device */
+enum {
+ LLOOP_UNBOUND,
+ LLOOP_BOUND,
+ LLOOP_RUNDOWN,
+};
+
+struct lloop_device {
+ int lo_number;
+ int lo_refcnt;
+ loff_t lo_offset;
+ loff_t lo_sizelimit;
+ int lo_flags;
+ int (*ioctl)(struct lloop_device *, int cmd,
+ unsigned long arg);
+
+ struct file * lo_backing_file;
+ struct block_device *lo_device;
+ unsigned lo_blocksize;
+
+ int old_gfp_mask;
+
+ spinlock_t lo_lock;
+ struct bio *lo_bio;
+ struct bio *lo_biotail;
+ int lo_state;
+ struct semaphore lo_sem;
+ struct semaphore lo_ctl_mutex;
+ struct semaphore lo_bh_mutex;
+ atomic_t lo_pending;
+
+ request_queue_t *lo_queue;
+
+ /* data to handle bio for lustre. */
+ struct lo_request_data {
+ struct brw_page lrd_pages[LLOOP_MAX_SEGMENTS];
+ struct obdo lrd_oa;
+ } lo_requests[1];
+
+};
+
+/*
+ * Loop flags
+ */
+enum {
+ LO_FLAGS_READ_ONLY = 1,
+};
+
+static int lloop_major;
+static int max_loop = 8;
+static struct lloop_device *loop_dev;
+static struct gendisk **disks;
+static struct semaphore lloop_mutex;
+static void *ll_iocontrol_magic = NULL;
+
+static loff_t get_loop_size(struct lloop_device *lo, struct file *file)
+{
+ loff_t size, offset, loopsize;
+
+ /* Compute loopsize in bytes */
+ size = i_size_read(file->f_mapping->host);
+ offset = lo->lo_offset;
+ loopsize = size - offset;
+ if (lo->lo_sizelimit > 0 && lo->lo_sizelimit < loopsize)
+ loopsize = lo->lo_sizelimit;
+
+ /*
+ * Unfortunately, if we want to do I/O on the device,
+ * the number of 512-byte sectors has to fit into a sector_t.
+ */
+ return loopsize >> 9;
+}
+
+static int do_bio_filebacked(struct lloop_device *lo, struct bio *bio)
+{
+ struct inode *inode = lo->lo_backing_file->f_dentry->d_inode;
+ struct ll_inode_info *lli = ll_i2info(inode);
+ struct lov_stripe_md *lsm = lli->lli_smd;
+ struct obd_info oinfo = {{{ 0 }}};
+ struct brw_page *pg = lo->lo_requests[0].lrd_pages;
+ struct obdo *oa = &lo->lo_requests[0].lrd_oa;
+ pgoff_t offset;
+ int ret, cmd, i, opc;
+ struct bio_vec *bvec;
+
+ BUG_ON(bio->bi_hw_segments > LLOOP_MAX_SEGMENTS);
+
+ offset = (pgoff_t)(bio->bi_sector << 9) + lo->lo_offset;
+ bio_for_each_segment(bvec, bio, i) {
+ BUG_ON(bvec->bv_offset != 0);
+ BUG_ON(bvec->bv_len != CFS_PAGE_SIZE);
+
+ pg->pg = bvec->bv_page;
+ pg->off = offset;
+ pg->count = bvec->bv_len;
+ pg->flag = OBD_BRW_SRVLOCK;
+
+ pg++;
+ offset += bvec->bv_len;
+ }
+
+ oa->o_mode = inode->i_mode;
+ oa->o_id = lsm->lsm_object_id;
+ oa->o_gr = lsm->lsm_object_gr;
+ oa->o_valid = OBD_MD_FLID | OBD_MD_FLMODE |
+ OBD_MD_FLTYPE |OBD_MD_FLGROUP;
+ obdo_from_inode(oa, inode, OBD_MD_FLFID | OBD_MD_FLGENER);
+
+ cmd = OBD_BRW_READ;
+ if (bio_rw(bio) == WRITE)
+ cmd = OBD_BRW_WRITE;
+
+ if (cmd == OBD_BRW_WRITE)
+ ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_BRW_WRITE, bio->bi_size);
+ else
+ ll_stats_ops_tally(ll_i2sbi(inode), LPROC_LL_BRW_READ, bio->bi_size);
+ oinfo.oi_oa = oa;
+ oinfo.oi_md = lsm;
+ opc = cmd & OBD_BRW_WRITE ? CAPA_OPC_OSS_WRITE : CAPA_OPC_OSS_RW;
+ oinfo.oi_capa = ll_osscapa_get(inode, opc);
+ ret = obd_brw(cmd, ll_i2dtexp(inode), &oinfo,
+ (obd_count)(i - bio->bi_idx),
+ lo->lo_requests[0].lrd_pages, NULL);
+ capa_put(oinfo.oi_capa);
+ if (ret == 0)
+ obdo_to_inode(inode, oa, OBD_MD_FLBLOCKS);
+ return ret;
+}
+
+
+/*
+ * Add bio to back of pending list
+ */
+static void loop_add_bio(struct lloop_device *lo, struct bio *bio)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&lo->lo_lock, flags);
+ if (lo->lo_biotail) {
+ lo->lo_biotail->bi_next = bio;
+ lo->lo_biotail = bio;
+ } else
+ lo->lo_bio = lo->lo_biotail = bio;
+ spin_unlock_irqrestore(&lo->lo_lock, flags);
+
+ up(&lo->lo_bh_mutex);
+}
+
+/*
+ * Grab first pending buffer
+ */
+static struct bio *loop_get_bio(struct lloop_device *lo)
+{
+ struct bio *bio;
+
+ spin_lock_irq(&lo->lo_lock);
+ if ((bio = lo->lo_bio)) {
+ if (bio == lo->lo_biotail)
+ lo->lo_biotail = NULL;
+ lo->lo_bio = bio->bi_next;
+ bio->bi_next = NULL;
+ }
+ spin_unlock_irq(&lo->lo_lock);
+
+ return bio;
+}
+
+static int loop_make_request(request_queue_t *q, struct bio *old_bio)
+{
+ struct lloop_device *lo = q->queuedata;
+ int rw = bio_rw(old_bio);
+
+ if (!lo)
+ goto out;
+
+ spin_lock_irq(&lo->lo_lock);
+ if (lo->lo_state != LLOOP_BOUND)
+ goto inactive;
+ atomic_inc(&lo->lo_pending);
+ spin_unlock_irq(&lo->lo_lock);
+
+ if (rw == WRITE) {
+ if (lo->lo_flags & LO_FLAGS_READ_ONLY)
+ goto err;
+ } else if (rw == READA) {
+ rw = READ;
+ } else if (rw != READ) {
+ CERROR("lloop: unknown command (%x)\n", rw);
+ goto err;
+ }
+ loop_add_bio(lo, old_bio);
+ return 0;
+err:
+ if (atomic_dec_and_test(&lo->lo_pending))
+ up(&lo->lo_bh_mutex);
+out:
+ bio_io_error(old_bio, old_bio->bi_size);
+ return 0;
+inactive:
+ spin_unlock_irq(&lo->lo_lock);
+ goto out;
+}
+
+/*
+ * kick off io on the underlying address space
+ */
+static void loop_unplug(request_queue_t *q)
+{
+ struct lloop_device *lo = q->queuedata;
+
+ clear_bit(QUEUE_FLAG_PLUGGED, &q->queue_flags);
+ blk_run_address_space(lo->lo_backing_file->f_mapping);
+}
+
+static inline void loop_handle_bio(struct lloop_device *lo, struct bio *bio)
+{
+ int ret;
+ ret = do_bio_filebacked(lo, bio);
+ bio_endio(bio, bio->bi_size, ret);
+}
+
+/*
+ * worker thread that handles reads/writes to file backed loop devices,
+ * to avoid blocking in our make_request_fn. it also does loop decrypting
+ * on reads for block backed loop, as that is too heavy to do from
+ * b_end_io context where irqs may be disabled.
+ */
+static int loop_thread(void *data)
+{
+ struct lloop_device *lo = data;
+ struct bio *bio;
+
+ daemonize("lloop%d", lo->lo_number);
+
+ set_user_nice(current, -20);
+
+ lo->lo_state = LLOOP_BOUND;
+ atomic_inc(&lo->lo_pending);
+
+ /*
+ * up sem, we are running
+ */
+ up(&lo->lo_sem);
+
+ for (;;) {
+ down_interruptible(&lo->lo_bh_mutex);
+ /*
+ * could be upped because of tear-down, not because of
+ * pending work
+ */
+ if (!atomic_read(&lo->lo_pending))
+ break;
+
+ bio = loop_get_bio(lo);
+ if (!bio) {
+ CWARN("lloop(minor: %d): missing bio\n", lo->lo_number);
+ continue;
+ }
+ loop_handle_bio(lo, bio);
+
+ /*
+ * upped both for pending work and tear-down, lo_pending
+ * will hit zero then
+ */
+ if (atomic_dec_and_test(&lo->lo_pending))
+ break;
+ }
+
+ up(&lo->lo_sem);
+ return 0;
+}
+
+static int loop_set_fd(struct lloop_device *lo, struct file *unused,
+ struct block_device *bdev, struct file *file)
+{
+ struct inode *inode;
+ struct address_space *mapping;
+ int lo_flags = 0;
+ int error;
+ loff_t size;
+
+ if (!try_module_get(THIS_MODULE))
+ return -ENODEV;
+
+ error = -EBUSY;
+ if (lo->lo_state != LLOOP_UNBOUND)
+ goto out;
+
+ mapping = file->f_mapping;
+ inode = mapping->host;
+
+ error = -EINVAL;
+ if (!S_ISREG(inode->i_mode) || inode->i_sb->s_magic != LL_SUPER_MAGIC)
+ goto out;
+
+ if (!(file->f_mode & FMODE_WRITE))
+ lo_flags |= LO_FLAGS_READ_ONLY;
+
+ size = get_loop_size(lo, file);
+
+ if ((loff_t)(sector_t)size != size) {
+ error = -EFBIG;
+ goto out;
+ }
+
+ /* remove all pages in cache so as dirty pages not to be existent. */
+ truncate_inode_pages(mapping, 0);
+
+ set_device_ro(bdev, (lo_flags & LO_FLAGS_READ_ONLY) != 0);
+
+ lo->lo_blocksize = CFS_PAGE_SIZE;
+ lo->lo_device = bdev;
+ lo->lo_flags = lo_flags;
+ lo->lo_backing_file = file;
+ lo->ioctl = NULL;
+ lo->lo_sizelimit = 0;
+ 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;
+
+ /*
+ * set queue make_request_fn, and add limits based on lower level
+ * device
+ */
+ blk_queue_make_request(lo->lo_queue, loop_make_request);
+ lo->lo_queue->queuedata = lo;
+ lo->lo_queue->unplug_fn = loop_unplug;
+
+ /* queue parameters */
+ blk_queue_hardsect_size(lo->lo_queue, CFS_PAGE_SIZE);
+ blk_queue_max_sectors(lo->lo_queue, LLOOP_MAX_SEGMENTS);
+ blk_queue_max_phys_segments(lo->lo_queue, LLOOP_MAX_SEGMENTS);
+
+ set_capacity(disks[lo->lo_number], size);
+ bd_set_size(bdev, size << 9);
+
+ set_blocksize(bdev, lo->lo_blocksize);
+
+ kernel_thread(loop_thread, lo, CLONE_KERNEL);
+ down(&lo->lo_sem);
+ return 0;
+
+ out:
+ /* This is safe: open() is still holding a reference. */
+ module_put(THIS_MODULE);
+ return error;
+}
+
+static int loop_clr_fd(struct lloop_device *lo, struct block_device *bdev,
+ int count)
+{
+ struct file *filp = lo->lo_backing_file;
+ int gfp = lo->old_gfp_mask;
+
+ if (lo->lo_state != LLOOP_BOUND)
+ return -ENXIO;
+
+ if (lo->lo_refcnt > count) /* we needed one fd for the ioctl */
+ return -EBUSY;
+
+ if (filp == NULL)
+ return -EINVAL;
+
+ spin_lock_irq(&lo->lo_lock);
+ lo->lo_state = LLOOP_RUNDOWN;
+ if (atomic_dec_and_test(&lo->lo_pending))
+ up(&lo->lo_bh_mutex);
+ spin_unlock_irq(&lo->lo_lock);
+
+ down(&lo->lo_sem);
+ lo->lo_backing_file = NULL;
+ lo->ioctl = NULL;
+ lo->lo_device = NULL;
+ lo->lo_offset = 0;
+ lo->lo_sizelimit = 0;
+ lo->lo_flags = 0;
+ invalidate_bdev(bdev, 0);
+ set_capacity(disks[lo->lo_number], 0);
+ bd_set_size(bdev, 0);
+ mapping_set_gfp_mask(filp->f_mapping, gfp);
+ lo->lo_state = LLOOP_UNBOUND;
+ fput(filp);
+ /* This is safe: open() is still holding a reference. */
+ module_put(THIS_MODULE);
+ return 0;
+}
+
+static int lo_open(struct inode *inode, struct file *file)
+{
+ struct lloop_device *lo = inode->i_bdev->bd_disk->private_data;
+
+ down(&lo->lo_ctl_mutex);
+ lo->lo_refcnt++;
+ up(&lo->lo_ctl_mutex);
+
+ return 0;
+}
+
+static int lo_release(struct inode *inode, struct file *file)
+{
+ struct lloop_device *lo = inode->i_bdev->bd_disk->private_data;
+
+ down(&lo->lo_ctl_mutex);
+ --lo->lo_refcnt;
+ up(&lo->lo_ctl_mutex);
+
+ return 0;
+}
+
+/* lloop device node's ioctl function. */
+static int lo_ioctl(struct inode *inode, struct file *unused,
+ unsigned int cmd, unsigned long arg)
+{
+ struct lloop_device *lo = inode->i_bdev->bd_disk->private_data;
+ struct block_device *bdev = inode->i_bdev;
+ int err = 0;
+
+ down(&lloop_mutex);
+ switch (cmd) {
+ case LL_IOC_LLOOP_DETACH: {
+ err = loop_clr_fd(lo, bdev, 2);
+ if (err == 0)
+ blkdev_put(bdev); /* grabbed in LLOOP_ATTACH */
+ break;
+ }
+
+ case LL_IOC_LLOOP_INFO: {
+ __u64 ino = 0;
+
+ if (lo->lo_state == LLOOP_BOUND)
+ ino = lo->lo_backing_file->f_dentry->d_inode->i_ino;
+
+ if (put_user(ino, (__u64 *)arg))
+ err = -EFAULT;
+ break;
+ }
+
+ default:
+ err = -EINVAL;
+ break;
+ }
+ up(&lloop_mutex);
+
+ return err;
+}
+
+static struct block_device_operations lo_fops = {
+ .owner = THIS_MODULE,
+ .open = lo_open,
+ .release = lo_release,
+ .ioctl = lo_ioctl,
+};
+
+/* dynamic iocontrol callback.
+ * This callback is registered in lloop_init and will be called by
+ * ll_iocontrol_call.
+ * This is a llite regular file ioctl function. It takes the responsibility
+ * of attaching a file, and detaching a file by a lloop's device numner.
+ */
+static enum llioc_iter lloop_ioctl(struct inode *unused, struct file *file,
+ unsigned int cmd, unsigned long arg,
+ void *magic, int *rcp)
+{
+ struct lloop_device *lo = NULL;
+ struct block_device *bdev = NULL;
+ int err = 0;
+ dev_t dev;
+
+ if (magic != ll_iocontrol_magic)
+ return LLIOC_CONT;
+
+ if (disks == NULL)
+ GOTO(out1, err = -ENODEV);
+
+ CWARN("Enter llop_ioctl\n");
+
+ down(&lloop_mutex);
+ switch (cmd) {
+ case LL_IOC_LLOOP_ATTACH: {
+ struct lloop_device *lo_free = NULL;
+ int i;
+
+ for (i = 0; i < max_loop; i++, lo = NULL) {
+ lo = &loop_dev[i];
+ if (lo->lo_state == LLOOP_UNBOUND) {
+ if (!lo_free)
+ lo_free = lo;
+ continue;
+ }
+ if (lo->lo_backing_file->f_dentry->d_inode ==
+ file->f_dentry->d_inode)
+ break;
+ }
+ if (lo || !lo_free)
+ GOTO(out, err = -EBUSY);
+
+ lo = lo_free;
+ dev = MKDEV(lloop_major, lo->lo_number);
+
+ /* quit if the used pointer is writable */
+ if (put_user((long)old_encode_dev(dev), (long*)arg))
+ GOTO(out, err = -EFAULT);
+
+ bdev = open_by_devnum(dev, file->f_mode);
+ if (IS_ERR(bdev))
+ GOTO(out, err = PTR_ERR(bdev));
+
+ get_file(file);
+ err = loop_set_fd(lo, NULL, bdev, file);
+ if (err) {
+ fput(file);
+ blkdev_put(bdev);
+ }
+
+ break;
+ }
+
+ case LL_IOC_LLOOP_DETACH_BYDEV: {
+ int minor;
+
+ dev = old_decode_dev(arg);
+ if (MAJOR(dev) != lloop_major)
+ GOTO(out, err = -EINVAL);
+
+ minor = MINOR(dev);
+ if (minor > max_loop - 1)
+ GOTO(out, err = -EINVAL);
+
+ lo = &loop_dev[minor];
+ if (lo->lo_state != LLOOP_BOUND)
+ GOTO(out, err = -EINVAL);
+
+ bdev = lo->lo_device;
+ err = loop_clr_fd(lo, bdev, 1);
+ if (err == 0)
+ blkdev_put(bdev); /* grabbed in LLOOP_ATTACH */
+
+ break;
+ }
+
+ default:
+ err = -EINVAL;
+ break;
+ }
+
+out:
+ up(&lloop_mutex);
+out1:
+ if (rcp)
+ *rcp = err;
+ return LLIOC_STOP;
+}
+
+static int __init lloop_init(void)
+{
+ int i;
+ unsigned int cmdlist[] = {
+ LL_IOC_LLOOP_ATTACH,
+ LL_IOC_LLOOP_DETACH_BYDEV,
+ };
+
+ if (max_loop < 1 || max_loop > 256) {
+ CWARN("lloop: invalid max_loop (must be between"
+ " 1 and 256), using default (8)\n");
+ max_loop = 8;
+ }
+
+ lloop_major = register_blkdev(0, "lloop");
+ if (lloop_major < 0)
+ return -EIO;
+
+ ll_iocontrol_magic = ll_iocontrol_register(lloop_ioctl, 2, cmdlist);
+ if (ll_iocontrol_magic == NULL)
+ goto out_mem1;
+
+ loop_dev = kmalloc(max_loop * sizeof(struct lloop_device), GFP_KERNEL);
+ if (!loop_dev)
+ goto out_mem1;
+ memset(loop_dev, 0, max_loop * sizeof(struct lloop_device));
+
+ disks = kmalloc(max_loop * sizeof(struct gendisk *), GFP_KERNEL);
+ if (!disks)
+ goto out_mem2;
+
+ for (i = 0; i < max_loop; i++) {
+ disks[i] = alloc_disk(1);
+ if (!disks[i])
+ goto out_mem3;
+ }
+
+ init_MUTEX(&lloop_mutex);
+
+ for (i = 0; i < max_loop; i++) {
+ struct lloop_device *lo = &loop_dev[i];
+ struct gendisk *disk = disks[i];
+
+ memset(lo, 0, sizeof(*lo));
+ lo->lo_queue = blk_alloc_queue(GFP_KERNEL);
+ if (!lo->lo_queue)
+ goto out_mem4;
+
+ init_MUTEX(&lo->lo_ctl_mutex);
+ init_MUTEX_LOCKED(&lo->lo_sem);
+ init_MUTEX_LOCKED(&lo->lo_bh_mutex);
+ lo->lo_number = i;
+ spin_lock_init(&lo->lo_lock);
+ disk->major = lloop_major;
+ disk->first_minor = i;
+ disk->fops = &lo_fops;
+ sprintf(disk->disk_name, "lloop%d", i);
+ disk->private_data = lo;
+ disk->queue = lo->lo_queue;
+ }
+
+ /* We cannot fail after we call this, so another loop!*/
+ for (i = 0; i < max_loop; i++)
+ add_disk(disks[i]);
+ return 0;
+
+out_mem4:
+ while (i--)
+ blk_put_queue(loop_dev[i].lo_queue);
+ i = max_loop;
+out_mem3:
+ while (i--)
+ put_disk(disks[i]);
+ kfree(disks);
+out_mem2:
+ kfree(loop_dev);
+out_mem1:
+ unregister_blkdev(lloop_major, "lloop");
+ ll_iocontrol_unregister(ll_iocontrol_magic);
+ CERROR("lloop: ran out of memory\n");
+ return -ENOMEM;
+}
+
+static void lloop_exit(void)
+{
+ int i;
+
+ ll_iocontrol_unregister(ll_iocontrol_magic);
+ for (i = 0; i < max_loop; i++) {
+ del_gendisk(disks[i]);
+ blk_put_queue(loop_dev[i].lo_queue);
+ put_disk(disks[i]);
+ }
+ if (unregister_blkdev(lloop_major, "lloop"))
+ CWARN("lloop: cannot unregister blkdev\n");
+
+ kfree(disks);
+ kfree(loop_dev);
+}
+
+module_init(lloop_init);
+module_exit(lloop_exit);
+
+CFS_MODULE_PARM(max_loop, "i", int, 0444, "maximum of lloop_device");
return rc;
}
+/* attach a regular file to virtual block device.
+ * return vaule:
+ * -1: fatal error
+ * 1: error, it always means the command run failed
+ * 0: success
+ */
+static int jt_blockdev_run_process(const char *file, char *argv[])
+{
+ pid_t pid;
+ int rc;
+
+ pid = vfork();
+ if (pid == 0) { /* child process */
+ /* don't print error messages */
+ close(1), close(2);
+ (void)execvp(file, argv);
+ exit(-1);
+ } else if (pid > 0) {
+ int status;
+
+ rc = waitpid(pid, &status, 0);
+ if (rc < 0 || !WIFEXITED(status))
+ return -1;
+
+ return WEXITSTATUS(status);
+ }
+
+ return -1;
+}
+
+static int jt_blockdev_find_module(const char *module)
+{
+ FILE *fp;
+ int found = 0;
+ char modname[256];
+
+ fp = fopen("/proc/modules", "r");
+ if (fp == NULL)
+ return -1;
+
+ while (fscanf(fp, "%s %*s %*s %*s %*s %*s", modname) == 1) {
+ if (strcmp(module, modname) == 0) {
+ found = 1;
+ break;
+ }
+ }
+ fclose(fp);
+
+ return found;
+}
+
+static int jt_blockdev_probe_module(const char *module)
+{
+ char buf[1024];
+ char *argv[10];
+ int c, rc;
+
+ if (jt_blockdev_find_module(module) == 1)
+ return 0;
+
+ /* run modprobe first */
+ c = 0;
+ argv[c++] = "/sbin/modprobe";
+ argv[c++] = "-q";
+ argv[c++] = (char *)module;
+ argv[c++] = NULL;
+ rc = jt_blockdev_run_process("modprobe", argv);
+ if (rc != 1)
+ return rc;
+
+ /* cannot find the module in default directory ... */
+ sprintf(buf, "../llite/%s.ko", module);
+ c = 0;
+ argv[c++] = "/sbin/insmod";
+ argv[c++] = buf;
+ argv[c++] = NULL;
+ rc = jt_blockdev_run_process("insmod", argv);
+ return rc ? -1 : 0;
+}
+
+int jt_blockdev_attach(int argc, char **argv)
+{
+ int rc, fd;
+ struct stat st;
+ char *filename, *devname;
+ unsigned long dev;
+
+ if (argc != 3)
+ return CMD_HELP;
+
+ if (jt_blockdev_probe_module("llite_lloop") < 0) {
+ fprintf(stderr, "error: cannot find module llite_lloop.(k)o\n");
+ return ENOENT;
+ }
+
+ filename = argv[1];
+ devname = argv[2];
+
+ fd = open(filename, O_RDWR);
+ if (fd < 0) {
+ fprintf(stderr, "file %s can't be opened(%s)\n\n",
+ filename, strerror(errno));
+ return CMD_HELP;
+ }
+
+ rc = ioctl(fd, LL_IOC_LLOOP_ATTACH, &dev);
+ if (rc < 0) {
+ rc = errno;
+ fprintf(stderr, "attach error(%s)\n", strerror(rc));
+ goto out;
+ }
+
+ rc = stat(devname, &st);
+ if (rc == 0 && (!S_ISBLK(st.st_mode) || st.st_rdev != dev)) {
+ rc = EEXIST;
+ } else if (rc < 0) {
+ if (errno == ENOENT &&
+ !mknod(devname, S_IFBLK|S_IRUSR|S_IWUSR, dev))
+ rc = 0;
+ else
+ rc = errno;
+ }
+
+ if (rc) {
+ fprintf(stderr, "error: the file %s could be attached to block "
+ "device %X but creating %s failed: %s\n"
+ "now detaching the block device..",
+ filename, (int)dev, devname, strerror(rc));
+
+ (void)ioctl(fd, LL_IOC_LLOOP_DETACH_BYDEV, dev);
+ fprintf(stderr, "%s\n", strerror(errno));
+ }
+out:
+ close(fd);
+ return -rc;
+}
+
+int jt_blockdev_detach(int argc, char **argv)
+{
+ char *filename;
+ int rc, fd;
+
+ if (argc != 2)
+ return CMD_HELP;
+
+ filename = argv[1];
+ fd = open(filename, O_RDONLY);
+ if (fd < 0) {
+ fprintf(stderr, "cannot open file %s error %s\n",
+ filename, strerror(errno));
+ return CMD_HELP;
+ }
+
+ rc = ioctl(fd, LL_IOC_LLOOP_DETACH, 0);
+ if (rc < 0) {
+ rc = errno;
+ fprintf(stderr, "detach error(%s)\n", strerror(rc));
+ } else {
+ (void)unlink(filename);
+ }
+
+ close(fd);
+ return -rc;
+}
+
+int jt_blockdev_info(int argc, char **argv)
+{
+ char *filename;
+ int rc, fd;
+ __u64 ino;
+
+ if (argc != 2)
+ return CMD_HELP;
+
+ filename = argv[1];
+ fd = open(filename, O_RDONLY);
+ if (fd < 0) {
+ fprintf(stderr, "cannot open file %s error: %s\n",
+ filename, strerror(errno));
+ return CMD_HELP;
+ }
+
+ rc = ioctl(fd, LL_IOC_LLOOP_INFO, &ino);
+ if (rc < 0) {
+ rc = errno;
+ fprintf(stderr, "error: %s\n", strerror(errno));
+ goto out;
+ }
+ fprintf(stdout, "lloop device info: ");
+ if (ino == 0ULL)
+ fprintf(stdout, "Not attached\n");
+ else
+ fprintf(stdout, "attached to inode %llu\n", ino);
+out:
+ close(fd);
+ return -rc;
+}
+
static void signal_server(int sig)
{
if (sig == SIGINT) {
git://git.whamcloud.com / fs / lustre-release.git / commitdiff