X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fblock%2Floop.c;h=9c3b94e8f03baa7d4138802e01b87e27e511c159;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=6f011d0d8e97a98c0aa661ae6a2223bb73a72fda;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 6f011d0d8..9c3b94e8f 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -213,9 +213,9 @@ static int do_lo_send_aops(struct loop_device *lo, struct bio_vec *bvec, struct address_space_operations *aops = mapping->a_ops; pgoff_t index; unsigned offset, bv_offs; - int len, ret = 0; + int len, ret; - down(&mapping->host->i_sem); + mutex_lock(&mapping->host->i_mutex); index = pos >> PAGE_CACHE_SHIFT; offset = pos & ((pgoff_t)PAGE_CACHE_SIZE - 1); bv_offs = bvec->bv_offset; @@ -232,9 +232,15 @@ static int do_lo_send_aops(struct loop_device *lo, struct bio_vec *bvec, page = grab_cache_page(mapping, index); if (unlikely(!page)) goto fail; - if (unlikely(aops->prepare_write(file, page, offset, - offset + size))) + 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)) { @@ -251,9 +257,15 @@ static int do_lo_send_aops(struct loop_device *lo, struct bio_vec *bvec, kunmap_atomic(kaddr, KM_USER0); } flush_dcache_page(page); - if (unlikely(aops->commit_write(file, page, offset, - offset + size))) + ret = aops->commit_write(file, page, offset, + offset + size); + if (unlikely(ret)) { + if (ret == AOP_TRUNCATED_PAGE) { + page_cache_release(page); + continue; + } goto unlock; + } if (unlikely(transfer_result)) goto unlock; bv_offs += size; @@ -264,8 +276,9 @@ static int do_lo_send_aops(struct loop_device *lo, struct bio_vec *bvec, unlock_page(page); page_cache_release(page); } + ret = 0; out: - up(&mapping->host->i_sem); + mutex_unlock(&mapping->host->i_mutex); return ret; unlock: unlock_page(page); @@ -281,7 +294,7 @@ fail: * This helper just factors out common code between do_lo_send_direct_write() * and do_lo_send_write(). */ -static inline int __do_lo_send_write(struct file *file, +static int __do_lo_send_write(struct file *file, u8 __user *buf, const int len, loff_t pos) { ssize_t bw; @@ -472,17 +485,11 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio) */ static void loop_add_bio(struct loop_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); } /* @@ -492,14 +499,12 @@ static struct bio *loop_get_bio(struct loop_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; } @@ -509,35 +514,28 @@ static int loop_make_request(request_queue_t *q, struct bio *old_bio) struct loop_device *lo = q->queuedata; int rw = bio_rw(old_bio); - if (!lo) - goto out; + if (rw == READA) + rw = READ; + + BUG_ON(!lo || (rw != READ && rw != WRITE)); spin_lock_irq(&lo->lo_lock); if (lo->lo_state != Lo_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) { - printk(KERN_ERR "loop: unknown command (%x)\n", rw); - goto err; - } + goto out; + if (unlikely(rw == WRITE && (lo->lo_flags & LO_FLAGS_READ_ONLY))) + goto out; + lo->lo_pending++; loop_add_bio(lo, old_bio); + spin_unlock_irq(&lo->lo_lock); + complete(&lo->lo_bh_done); return 0; -err: - if (atomic_dec_and_test(&lo->lo_pending)) - up(&lo->lo_bh_mutex); + out: + if (lo->lo_pending == 0) + complete(&lo->lo_bh_done); + spin_unlock_irq(&lo->lo_lock); bio_io_error(old_bio, old_bio->bi_size); return 0; -inactive: - spin_unlock_irq(&lo->lo_lock); - goto out; } /* @@ -560,13 +558,11 @@ static void do_loop_switch(struct loop_device *, struct switch_request *); static inline void loop_handle_bio(struct loop_device *lo, struct bio *bio) { - int ret; - if (unlikely(!bio->bi_bdev)) { do_loop_switch(lo, bio->bi_private); bio_put(bio); } else { - ret = do_bio_filebacked(lo, bio); + int ret = do_bio_filebacked(lo, bio); bio_endio(bio, bio->bi_size, ret); } } @@ -594,38 +590,46 @@ static int loop_thread(void *data) set_user_nice(current, -20); lo->lo_state = Lo_bound; - atomic_inc(&lo->lo_pending); + lo->lo_pending = 1; /* - * up sem, we are running + * complete it, we are running */ - up(&lo->lo_sem); + complete(&lo->lo_done); for (;;) { - down_interruptible(&lo->lo_bh_mutex); + int pending; + + if (wait_for_completion_interruptible(&lo->lo_bh_done)) + continue; + + spin_lock_irq(&lo->lo_lock); + /* - * could be upped because of tear-down, not because of - * pending work + * could be completed because of tear-down, not pending work */ - if (!atomic_read(&lo->lo_pending)) + if (unlikely(!lo->lo_pending)) { + spin_unlock_irq(&lo->lo_lock); break; + } bio = loop_get_bio(lo); - if (!bio) { - printk("loop: missing bio\n"); - continue; - } + lo->lo_pending--; + pending = lo->lo_pending; + spin_unlock_irq(&lo->lo_lock); + + BUG_ON(!bio); 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)) + if (unlikely(!pending)) break; } - up(&lo->lo_sem); + complete(&lo->lo_done); return 0; } @@ -835,8 +839,10 @@ static int loop_set_fd(struct loop_device *lo, struct file *lo_file, set_blocksize(bdev, lo_blocksize); - kernel_thread(loop_thread, lo, CLONE_KERNEL); - down(&lo->lo_sem); + error = kernel_thread(loop_thread, lo, CLONE_KERNEL); + if (error < 0) + goto out_putf; + wait_for_completion(&lo->lo_done); return 0; out_putf: @@ -887,7 +893,7 @@ loop_init_xfer(struct loop_device *lo, struct loop_func_table *xfer, static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev) { struct file *filp = lo->lo_backing_file; - int gfp = lo->old_gfp_mask; + gfp_t gfp = lo->old_gfp_mask; if (lo->lo_state != Lo_bound) return -ENXIO; @@ -900,11 +906,12 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev) spin_lock_irq(&lo->lo_lock); lo->lo_state = Lo_rundown; - if (atomic_dec_and_test(&lo->lo_pending)) - up(&lo->lo_bh_mutex); + lo->lo_pending--; + if (!lo->lo_pending) + complete(&lo->lo_bh_done); spin_unlock_irq(&lo->lo_lock); - down(&lo->lo_sem); + wait_for_completion(&lo->lo_done); lo->lo_backing_file = NULL; @@ -1139,7 +1146,7 @@ static int lo_ioctl(struct inode * inode, struct file * file, struct loop_device *lo = inode->i_bdev->bd_disk->private_data; int err; - down(&lo->lo_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); switch (cmd) { case LOOP_SET_FD: err = loop_set_fd(lo, file, inode->i_bdev, arg); @@ -1165,7 +1172,7 @@ static int lo_ioctl(struct inode * inode, struct file * file, default: err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; } - up(&lo->lo_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); return err; } @@ -1173,9 +1180,9 @@ static int lo_open(struct inode *inode, struct file *file) { struct loop_device *lo = inode->i_bdev->bd_disk->private_data; - down(&lo->lo_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); lo->lo_refcnt++; - up(&lo->lo_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); return 0; } @@ -1184,9 +1191,9 @@ static int lo_release(struct inode *inode, struct file *file) { struct loop_device *lo = inode->i_bdev->bd_disk->private_data; - down(&lo->lo_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); --lo->lo_refcnt; - up(&lo->lo_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); return 0; } @@ -1228,12 +1235,12 @@ int loop_unregister_transfer(int number) xfer_funcs[n] = NULL; for (lo = &loop_dev[0]; lo < &loop_dev[max_loop]; lo++) { - down(&lo->lo_ctl_mutex); + mutex_lock(&lo->lo_ctl_mutex); if (lo->lo_encryption == xfer) loop_release_xfer(lo); - up(&lo->lo_ctl_mutex); + mutex_unlock(&lo->lo_ctl_mutex); } return 0; @@ -1280,9 +1287,9 @@ static int __init loop_init(void) 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); + mutex_init(&lo->lo_ctl_mutex); + init_completion(&lo->lo_done); + init_completion(&lo->lo_bh_done); lo->lo_number = i; spin_lock_init(&lo->lo_lock); disk->major = LOOP_MAJOR; @@ -1302,7 +1309,7 @@ static int __init loop_init(void) out_mem4: while (i--) - blk_put_queue(loop_dev[i].lo_queue); + blk_cleanup_queue(loop_dev[i].lo_queue); devfs_remove("loop"); i = max_loop; out_mem3: @@ -1323,7 +1330,7 @@ static void loop_exit(void) for (i = 0; i < max_loop; i++) { del_gendisk(disks[i]); - blk_put_queue(loop_dev[i].lo_queue); + blk_cleanup_queue(loop_dev[i].lo_queue); put_disk(disks[i]); } devfs_remove("loop");