Commit 4af1a041 authored by NeilBrown's avatar NeilBrown
Browse files

md: move GET_BITMAP_FILE ioctl out from mddev_lock. 



It makes more sense to report bitmap_info->file, rather than
bitmap->file (the later is only available once the array is
active).

With that change, use mddev->lock to protect bitmap_info being
set to NULL, and we can call get_bitmap_file() without taking
the mutex.

Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 1e594bb2

drivers/md/md.c

+32 −26
Original line number Diff line number Diff line
@@ -5292,8 +5292,11 @@ static int do_md_stop(struct mddev *mddev, int mode, 


		bitmap_destroy(mddev);

		if (mddev->bitmap_info.file) {

			fput(mddev->bitmap_info.file);

			struct file *f = mddev->bitmap_info.file;

			spin_lock(&mddev->lock);

			mddev->bitmap_info.file = NULL;

			spin_unlock(&mddev->lock);

			fput(f);

		}

		mddev->bitmap_info.offset = 0;
@@ -5503,32 +5506,30 @@ static int get_bitmap_file(struct mddev *mddev, void __user * arg) 
{

	mdu_bitmap_file_t *file = NULL; /* too big for stack allocation */

	char *ptr;

	int err = -ENOMEM;

	int err;



	file = kmalloc(sizeof(*file), GFP_NOIO);



	if (!file)

		goto out;

		return -ENOMEM;



	err = 0;

	spin_lock(&mddev->lock);

	/* bitmap disabled, zero the first byte and copy out */

	if (!mddev->bitmap || !mddev->bitmap->storage.file) {

	if (!mddev->bitmap_info.file)

		file->pathname[0] = '\0';

		goto copy_out;

	}



	ptr = d_path(&mddev->bitmap->storage.file->f_path,

		     file->pathname, sizeof(file->pathname));

	if (IS_ERR(ptr))

		goto out;



	else if ((ptr = d_path(&mddev->bitmap_info.file->f_path,

			       file->pathname, sizeof(file->pathname))),

		 IS_ERR(ptr))

		err = PTR_ERR(ptr);

	else

		memmove(file->pathname, ptr,

			sizeof(file->pathname)-(ptr-file->pathname));

	spin_unlock(&mddev->lock);



copy_out:

	err = 0;

	if (copy_to_user(arg, file, sizeof(*file)))

	if (err == 0 &&

	    copy_to_user(arg, file, sizeof(*file)))

		err = -EFAULT;

out:



	kfree(file);

	return err;

}
@@ -5900,9 +5901,13 @@ static int set_bitmap_file(struct mddev *mddev, int fd) 
		mddev->pers->quiesce(mddev, 0);

	}

	if (fd < 0) {

		if (mddev->bitmap_info.file)

			fput(mddev->bitmap_info.file);

		struct file *f = mddev->bitmap_info.file;

		if (f) {

			spin_lock(&mddev->lock);

			mddev->bitmap_info.file = NULL;

			spin_unlock(&mddev->lock);

			fput(f);

		}

	}



	return err;
@@ -6315,6 +6320,11 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode, 
	case SET_DISK_FAULTY:

		err = set_disk_faulty(mddev, new_decode_dev(arg));

		goto out;



	case GET_BITMAP_FILE:

		err = get_bitmap_file(mddev, argp);

		goto out;



	}



	if (cmd == ADD_NEW_DISK)
@@ -6406,10 +6416,6 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode, 
	 * Commands even a read-only array can execute:

	 */

	switch (cmd) {

	case GET_BITMAP_FILE:

		err = get_bitmap_file(mddev, argp);

		goto unlock;



	case RESTART_ARRAY_RW:

		err = restart_array(mddev);

		goto unlock;

drivers/md/md.h

+1 −0
Original line number Diff line number Diff line
@@ -393,6 +393,7 @@ struct mddev { 
	 *   in_sync - and related safemode and MD_CHANGE changes

	 *   pers (also protected by reconfig_mutex and pending IO).

	 *   clearing ->bitmap

	 *   clearing ->bitmap_info.file

	 */

	spinlock_t			lock;

	wait_queue_head_t		sb_wait;	/* for waiting on superblock updates */

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