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path: root/drivers/block/loop.c
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Diffstat (limited to 'drivers/block/loop.c')
-rw-r--r--drivers/block/loop.c98
1 files changed, 41 insertions, 57 deletions
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 3c74ea729fc..68b0471ad5a 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -50,7 +50,6 @@
*
*/
-#include <linux/config.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/sched.h>
@@ -63,7 +62,6 @@
#include <linux/blkdev.h>
#include <linux/blkpg.h>
#include <linux/init.h>
-#include <linux/devfs_fs_kernel.h>
#include <linux/smp_lock.h>
#include <linux/swap.h>
#include <linux/slab.h>
@@ -74,6 +72,7 @@
#include <linux/completion.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
+#include <linux/kthread.h>
#include <asm/uaccess.h>
@@ -210,7 +209,7 @@ static int do_lo_send_aops(struct loop_device *lo, struct bio_vec *bvec,
{
struct file *file = lo->lo_backing_file; /* kudos to NFsckingS */
struct address_space *mapping = file->f_mapping;
- struct address_space_operations *aops = mapping->a_ops;
+ const struct address_space_operations *aops = mapping->a_ops;
pgoff_t index;
unsigned offset, bv_offs;
int len, ret;
@@ -524,15 +523,12 @@ static int loop_make_request(request_queue_t *q, struct bio *old_bio)
goto out;
if (unlikely(rw == WRITE && (lo->lo_flags & LO_FLAGS_READ_ONLY)))
goto out;
- lo->lo_pending++;
loop_add_bio(lo, old_bio);
+ wake_up(&lo->lo_event);
spin_unlock_irq(&lo->lo_lock);
- complete(&lo->lo_bh_done);
return 0;
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;
@@ -572,14 +568,18 @@ static inline void loop_handle_bio(struct loop_device *lo, struct bio *bio)
* 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.
+ *
+ * Loop explanation: loop_clr_fd() sets lo_state to Lo_rundown before
+ * calling kthread_stop(). Therefore once kthread_should_stop() is
+ * true, make_request will not place any more requests. Therefore
+ * once kthread_should_stop() is true and lo_bio is NULL, we are
+ * done with the loop.
*/
static int loop_thread(void *data)
{
struct loop_device *lo = data;
struct bio *bio;
- daemonize("loop%d", lo->lo_number);
-
/*
* loop can be used in an encrypted device,
* hence, it mustn't be stopped at all
@@ -589,47 +589,21 @@ static int loop_thread(void *data)
set_user_nice(current, -20);
- lo->lo_state = Lo_bound;
- lo->lo_pending = 1;
-
- /*
- * complete it, we are running
- */
- complete(&lo->lo_done);
+ while (!kthread_should_stop() || lo->lo_bio) {
- for (;;) {
- int pending;
+ wait_event_interruptible(lo->lo_event,
+ lo->lo_bio || kthread_should_stop());
- if (wait_for_completion_interruptible(&lo->lo_bh_done))
+ if (!lo->lo_bio)
continue;
-
spin_lock_irq(&lo->lo_lock);
-
- /*
- * could be completed because of tear-down, not pending work
- */
- if (unlikely(!lo->lo_pending)) {
- spin_unlock_irq(&lo->lo_lock);
- break;
- }
-
bio = loop_get_bio(lo);
- 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 (unlikely(!pending))
- break;
}
- complete(&lo->lo_done);
return 0;
}
@@ -664,7 +638,8 @@ static void do_loop_switch(struct loop_device *lo, struct switch_request *p)
mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask);
lo->lo_backing_file = file;
- lo->lo_blocksize = mapping->host->i_blksize;
+ 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));
complete(&p->wait);
@@ -784,7 +759,7 @@ 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)) {
- struct address_space_operations *aops = mapping->a_ops;
+ 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.
@@ -796,7 +771,9 @@ static int loop_set_fd(struct loop_device *lo, struct file *lo_file,
if (!(lo_flags & LO_FLAGS_USE_AOPS) && !file->f_op->write)
lo_flags |= LO_FLAGS_READ_ONLY;
- lo_blocksize = inode->i_blksize;
+ lo_blocksize = S_ISBLK(inode->i_mode) ?
+ inode->i_bdev->bd_block_size : PAGE_SIZE;
+
error = 0;
} else {
goto out_putf;
@@ -839,12 +816,26 @@ static int loop_set_fd(struct loop_device *lo, struct file *lo_file,
set_blocksize(bdev, lo_blocksize);
- error = kernel_thread(loop_thread, lo, CLONE_KERNEL);
- if (error < 0)
- goto out_putf;
- wait_for_completion(&lo->lo_done);
+ lo->lo_thread = kthread_create(loop_thread, lo, "loop%d",
+ lo->lo_number);
+ if (IS_ERR(lo->lo_thread)) {
+ error = PTR_ERR(lo->lo_thread);
+ goto out_clr;
+ }
+ lo->lo_state = Lo_bound;
+ wake_up_process(lo->lo_thread);
return 0;
+out_clr:
+ lo->lo_thread = NULL;
+ lo->lo_device = NULL;
+ lo->lo_backing_file = NULL;
+ lo->lo_flags = 0;
+ set_capacity(disks[lo->lo_number], 0);
+ invalidate_bdev(bdev, 0);
+ bd_set_size(bdev, 0);
+ mapping_set_gfp_mask(mapping, lo->old_gfp_mask);
+ lo->lo_state = Lo_unbound;
out_putf:
fput(file);
out:
@@ -906,12 +897,9 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev)
spin_lock_irq(&lo->lo_lock);
lo->lo_state = Lo_rundown;
- lo->lo_pending--;
- if (!lo->lo_pending)
- complete(&lo->lo_bh_done);
spin_unlock_irq(&lo->lo_lock);
- wait_for_completion(&lo->lo_done);
+ kthread_stop(lo->lo_thread);
lo->lo_backing_file = NULL;
@@ -924,6 +912,7 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev)
lo->lo_sizelimit = 0;
lo->lo_encrypt_key_size = 0;
lo->lo_flags = 0;
+ lo->lo_thread = NULL;
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);
@@ -1277,8 +1266,6 @@ static int __init loop_init(void)
goto out_mem3;
}
- devfs_mk_dir("loop");
-
for (i = 0; i < max_loop; i++) {
struct loop_device *lo = &loop_dev[i];
struct gendisk *disk = disks[i];
@@ -1288,15 +1275,14 @@ static int __init loop_init(void)
if (!lo->lo_queue)
goto out_mem4;
mutex_init(&lo->lo_ctl_mutex);
- init_completion(&lo->lo_done);
- init_completion(&lo->lo_bh_done);
lo->lo_number = i;
+ lo->lo_thread = NULL;
+ init_waitqueue_head(&lo->lo_event);
spin_lock_init(&lo->lo_lock);
disk->major = LOOP_MAJOR;
disk->first_minor = i;
disk->fops = &lo_fops;
sprintf(disk->disk_name, "loop%d", i);
- sprintf(disk->devfs_name, "loop/%d", i);
disk->private_data = lo;
disk->queue = lo->lo_queue;
}
@@ -1310,7 +1296,6 @@ static int __init loop_init(void)
out_mem4:
while (i--)
blk_cleanup_queue(loop_dev[i].lo_queue);
- devfs_remove("loop");
i = max_loop;
out_mem3:
while (i--)
@@ -1333,7 +1318,6 @@ static void loop_exit(void)
blk_cleanup_queue(loop_dev[i].lo_queue);
put_disk(disks[i]);
}
- devfs_remove("loop");
if (unregister_blkdev(LOOP_MAJOR, "loop"))
printk(KERN_WARNING "loop: cannot unregister blkdev\n");
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-12 14:22:18 +0000