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Commit 278f6679 authored by Jeff Mahoney's avatar Jeff Mahoney Committed by Jeff Mahoney
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reiserfs: locking, handle nested locks properly 



The reiserfs write lock replaced the BKL and uses similar semantics.

Frederic's locking code makes a distinction between when the lock is nested
and when it's being acquired/released, but I don't think that's the right
distinction to make.

The right distinction is between the lock being released at end-of-use and
the lock being released for a schedule. The unlock should return the depth
and the lock should restore it, rather than the other way around as it is now.

This patch implements that and adds a number of places where the lock
should be dropped.

Signed-off-by: default avatarJeff Mahoney <jeffm@suse.com>
parent 4c05141d

fs/reiserfs/bitmap.c

+3 −2
Original line number Diff line number Diff line
@@ -1340,10 +1340,11 @@ struct buffer_head *reiserfs_read_bitmap_block(struct super_block *sb, 
		                 "reading failed", __func__, block);

	else {

		if (buffer_locked(bh)) {

			int depth;

			PROC_INFO_INC(sb, scan_bitmap.wait);

			reiserfs_write_unlock(sb);

			depth = reiserfs_write_unlock_nested(sb);

			__wait_on_buffer(bh);

			reiserfs_write_lock(sb);

			reiserfs_write_lock_nested(sb, depth);

		}

		BUG_ON(!buffer_uptodate(bh));

		BUG_ON(atomic_read(&bh->b_count) == 0);

fs/reiserfs/dir.c

+4 −3
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ int reiserfs_readdir_inode(struct inode *inode, struct dir_context *ctx) 
	char small_buf[32];	/* avoid kmalloc if we can */

	struct reiserfs_dir_entry de;

	int ret = 0;

	int depth;



	reiserfs_write_lock(inode->i_sb);
@@ -181,17 +182,17 @@ int reiserfs_readdir_inode(struct inode *inode, struct dir_context *ctx) 
				 * Since filldir might sleep, we can release

				 * the write lock here for other waiters

				 */

				reiserfs_write_unlock(inode->i_sb);

				depth = reiserfs_write_unlock_nested(inode->i_sb);

				if (!dir_emit

				    (ctx, local_buf, d_reclen, d_ino,

				     DT_UNKNOWN)) {

					reiserfs_write_lock(inode->i_sb);

					reiserfs_write_lock_nested(inode->i_sb, depth);

					if (local_buf != small_buf) {

						kfree(local_buf);

					}

					goto end;

				}

				reiserfs_write_lock(inode->i_sb);

				reiserfs_write_lock_nested(inode->i_sb, depth);

				if (local_buf != small_buf) {

					kfree(local_buf);

				}

fs/reiserfs/fix_node.c

+14 −12
Original line number Diff line number Diff line
@@ -1022,9 +1022,9 @@ static int get_far_parent(struct tree_balance *tb, 
	if (buffer_locked(*pcom_father)) {



		/* Release the write lock while the buffer is busy */

		reiserfs_write_unlock(tb->tb_sb);

		int depth = reiserfs_write_unlock_nested(tb->tb_sb);

		__wait_on_buffer(*pcom_father);

		reiserfs_write_lock(tb->tb_sb);

		reiserfs_write_lock_nested(tb->tb_sb, depth);

		if (FILESYSTEM_CHANGED_TB(tb)) {

			brelse(*pcom_father);

			return REPEAT_SEARCH;
@@ -1929,9 +1929,9 @@ static int get_direct_parent(struct tree_balance *tb, int h) 
		return REPEAT_SEARCH;



	if (buffer_locked(bh)) {

		reiserfs_write_unlock(tb->tb_sb);

		int depth = reiserfs_write_unlock_nested(tb->tb_sb);

		__wait_on_buffer(bh);

		reiserfs_write_lock(tb->tb_sb);

		reiserfs_write_lock_nested(tb->tb_sb, depth);

		if (FILESYSTEM_CHANGED_TB(tb))

			return REPEAT_SEARCH;

	}
@@ -1952,6 +1952,7 @@ static int get_neighbors(struct tree_balance *tb, int h) 
	unsigned long son_number;

	struct super_block *sb = tb->tb_sb;

	struct buffer_head *bh;

	int depth;



	PROC_INFO_INC(sb, get_neighbors[h]);
@@ -1969,9 +1970,9 @@ static int get_neighbors(struct tree_balance *tb, int h) 
		     tb->FL[h]) ? tb->lkey[h] : B_NR_ITEMS(tb->

								       FL[h]);

		son_number = B_N_CHILD_NUM(tb->FL[h], child_position);

		reiserfs_write_unlock(sb);

		depth = reiserfs_write_unlock_nested(tb->tb_sb);

		bh = sb_bread(sb, son_number);

		reiserfs_write_lock(sb);

		reiserfs_write_lock_nested(tb->tb_sb, depth);

		if (!bh)

			return IO_ERROR;

		if (FILESYSTEM_CHANGED_TB(tb)) {
@@ -2009,9 +2010,9 @@ static int get_neighbors(struct tree_balance *tb, int h) 
		child_position =

		    (bh == tb->FR[h]) ? tb->rkey[h] + 1 : 0;

		son_number = B_N_CHILD_NUM(tb->FR[h], child_position);

		reiserfs_write_unlock(sb);

		depth = reiserfs_write_unlock_nested(tb->tb_sb);

		bh = sb_bread(sb, son_number);

		reiserfs_write_lock(sb);

		reiserfs_write_lock_nested(tb->tb_sb, depth);

		if (!bh)

			return IO_ERROR;

		if (FILESYSTEM_CHANGED_TB(tb)) {
@@ -2272,6 +2273,7 @@ static int wait_tb_buffers_until_unlocked(struct tree_balance *tb) 
		}



		if (locked) {

			int depth;

#ifdef CONFIG_REISERFS_CHECK

			repeat_counter++;

			if ((repeat_counter % 10000) == 0) {
@@ -2286,9 +2288,9 @@ static int wait_tb_buffers_until_unlocked(struct tree_balance *tb) 
				    REPEAT_SEARCH : CARRY_ON;

			}

#endif

			reiserfs_write_unlock(tb->tb_sb);

			depth = reiserfs_write_unlock_nested(tb->tb_sb);

			__wait_on_buffer(locked);

			reiserfs_write_lock(tb->tb_sb);

			reiserfs_write_lock_nested(tb->tb_sb, depth);

			if (FILESYSTEM_CHANGED_TB(tb))

				return REPEAT_SEARCH;

		}
@@ -2359,9 +2361,9 @@ int fix_nodes(int op_mode, struct tree_balance *tb, 


	/* if it possible in indirect_to_direct conversion */

	if (buffer_locked(tbS0)) {

		reiserfs_write_unlock(tb->tb_sb);

		int depth = reiserfs_write_unlock_nested(tb->tb_sb);

		__wait_on_buffer(tbS0);

		reiserfs_write_lock(tb->tb_sb);

		reiserfs_write_lock_nested(tb->tb_sb, depth);

		if (FILESYSTEM_CHANGED_TB(tb))

			return REPEAT_SEARCH;

	}

fs/reiserfs/inode.c

+36 −41
Original line number Diff line number Diff line
@@ -41,11 +41,10 @@ void reiserfs_evict_inode(struct inode *inode) 


	/* The = 0 happens when we abort creating a new inode for some reason like lack of space.. */

	if (!(inode->i_state & I_NEW) && INODE_PKEY(inode)->k_objectid != 0) {	/* also handles bad_inode case */

		int depth;



		reiserfs_delete_xattrs(inode);



		depth = reiserfs_write_lock_once(inode->i_sb);

		reiserfs_write_lock(inode->i_sb);



		if (journal_begin(&th, inode->i_sb, jbegin_count))

			goto out;
@@ -74,7 +73,7 @@ void reiserfs_evict_inode(struct inode *inode) 
		remove_save_link(inode, 0 /* not truncate */ );	/* we can't do anything

								 * about an error here */

out:

		reiserfs_write_unlock_once(inode->i_sb, depth);

		reiserfs_write_unlock(inode->i_sb);

	} else {

		/* no object items are in the tree */

		;
@@ -611,7 +610,6 @@ int reiserfs_get_block(struct inode *inode, sector_t block, 
	__le32 *item;

	int done;

	int fs_gen;

	int lock_depth;

	struct reiserfs_transaction_handle *th = NULL;

	/* space reserved in transaction batch:

	   . 3 balancings in direct->indirect conversion
@@ -627,11 +625,11 @@ int reiserfs_get_block(struct inode *inode, sector_t block, 
	loff_t new_offset =

	    (((loff_t) block) << inode->i_sb->s_blocksize_bits) + 1;



	lock_depth = reiserfs_write_lock_once(inode->i_sb);

	reiserfs_write_lock(inode->i_sb);

	version = get_inode_item_key_version(inode);



	if (!file_capable(inode, block)) {

		reiserfs_write_unlock_once(inode->i_sb, lock_depth);

		reiserfs_write_unlock(inode->i_sb);

		return -EFBIG;

	}
@@ -643,7 +641,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block, 
		/* find number of block-th logical block of the file */

		ret = _get_block_create_0(inode, block, bh_result,

					  create | GET_BLOCK_READ_DIRECT);

		reiserfs_write_unlock_once(inode->i_sb, lock_depth);

		reiserfs_write_unlock(inode->i_sb);

		return ret;

	}

	/*
@@ -761,7 +759,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block, 
		if (!dangle && th)

			retval = reiserfs_end_persistent_transaction(th);



		reiserfs_write_unlock_once(inode->i_sb, lock_depth);

		reiserfs_write_unlock(inode->i_sb);



		/* the item was found, so new blocks were not added to the file

		 ** there is no need to make sure the inode is updated with this
@@ -1012,11 +1010,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block, 
		 * long time.  reschedule if needed and also release the write

		 * lock for others.

		 */

		if (need_resched()) {

			reiserfs_write_unlock_once(inode->i_sb, lock_depth);

			schedule();

			lock_depth = reiserfs_write_lock_once(inode->i_sb);

		}

		reiserfs_cond_resched(inode->i_sb);



		retval = search_for_position_by_key(inode->i_sb, &key, &path);

		if (retval == IO_ERROR) {
@@ -1051,7 +1045,7 @@ int reiserfs_get_block(struct inode *inode, sector_t block, 
			retval = err;

	}



	reiserfs_write_unlock_once(inode->i_sb, lock_depth);

	reiserfs_write_unlock(inode->i_sb);

	reiserfs_check_path(&path);

	return retval;

}
@@ -1510,14 +1504,15 @@ struct inode *reiserfs_iget(struct super_block *s, const struct cpu_key *key) 
{

	struct inode *inode;

	struct reiserfs_iget_args args;

	int depth;



	args.objectid = key->on_disk_key.k_objectid;

	args.dirid = key->on_disk_key.k_dir_id;

	reiserfs_write_unlock(s);

	depth = reiserfs_write_unlock_nested(s);

	inode = iget5_locked(s, key->on_disk_key.k_objectid,

			     reiserfs_find_actor, reiserfs_init_locked_inode,

			     (void *)(&args));

	reiserfs_write_lock(s);

	reiserfs_write_lock_nested(s, depth);

	if (!inode)

		return ERR_PTR(-ENOMEM);
@@ -1781,6 +1776,7 @@ int reiserfs_new_inode(struct reiserfs_transaction_handle *th, 
	struct stat_data sd;

	int retval;

	int err;

	int depth;



	BUG_ON(!th->t_trans_id);
@@ -1813,10 +1809,10 @@ int reiserfs_new_inode(struct reiserfs_transaction_handle *th, 
	memcpy(INODE_PKEY(inode), &(ih.ih_key), KEY_SIZE);

	args.dirid = le32_to_cpu(ih.ih_key.k_dir_id);



	reiserfs_write_unlock(inode->i_sb);

	depth = reiserfs_write_unlock_nested(inode->i_sb);

	err = insert_inode_locked4(inode, args.objectid,

			     reiserfs_find_actor, &args);

	reiserfs_write_lock(inode->i_sb);

	reiserfs_write_lock_nested(inode->i_sb, depth);

	if (err) {

		err = -EINVAL;

		goto out_bad_inode;
@@ -2108,9 +2104,8 @@ int reiserfs_truncate_file(struct inode *inode, int update_timestamps) 
	int error;

	struct buffer_head *bh = NULL;

	int err2;

	int lock_depth;



	lock_depth = reiserfs_write_lock_once(inode->i_sb);

	reiserfs_write_lock(inode->i_sb);



	if (inode->i_size > 0) {

		error = grab_tail_page(inode, &page, &bh);
@@ -2179,7 +2174,7 @@ int reiserfs_truncate_file(struct inode *inode, int update_timestamps) 
		page_cache_release(page);

	}



	reiserfs_write_unlock_once(inode->i_sb, lock_depth);

	reiserfs_write_unlock(inode->i_sb);



	return 0;

      out:
@@ -2188,7 +2183,7 @@ int reiserfs_truncate_file(struct inode *inode, int update_timestamps) 
		page_cache_release(page);

	}



	reiserfs_write_unlock_once(inode->i_sb, lock_depth);

	reiserfs_write_unlock(inode->i_sb);



	return error;

}
@@ -2653,10 +2648,11 @@ int __reiserfs_write_begin(struct page *page, unsigned from, unsigned len) 
	struct inode *inode = page->mapping->host;

	int ret;

	int old_ref = 0;

	int depth;



	reiserfs_write_unlock(inode->i_sb);

	depth = reiserfs_write_unlock_nested(inode->i_sb);

	reiserfs_wait_on_write_block(inode->i_sb);

	reiserfs_write_lock(inode->i_sb);

	reiserfs_write_lock_nested(inode->i_sb, depth);



	fix_tail_page_for_writing(page);

	if (reiserfs_transaction_running(inode->i_sb)) {
@@ -2713,7 +2709,6 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, 
	int update_sd = 0;

	struct reiserfs_transaction_handle *th;

	unsigned start;

	int lock_depth = 0;

	bool locked = false;



	if ((unsigned long)fsdata & AOP_FLAG_CONT_EXPAND)
@@ -2742,7 +2737,7 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, 
	 */

	if (pos + copied > inode->i_size) {

		struct reiserfs_transaction_handle myth;

		lock_depth = reiserfs_write_lock_once(inode->i_sb);

		reiserfs_write_lock(inode->i_sb);

		locked = true;

		/* If the file have grown beyond the border where it

		   can have a tail, unmark it as needing a tail
@@ -2773,7 +2768,7 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, 
	}

	if (th) {

		if (!locked) {

			lock_depth = reiserfs_write_lock_once(inode->i_sb);

			reiserfs_write_lock(inode->i_sb);

			locked = true;

		}

		if (!update_sd)
@@ -2785,7 +2780,7 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, 


      out:

	if (locked)

		reiserfs_write_unlock_once(inode->i_sb, lock_depth);

		reiserfs_write_unlock(inode->i_sb);

	unlock_page(page);

	page_cache_release(page);
@@ -2795,7 +2790,7 @@ static int reiserfs_write_end(struct file *file, struct address_space *mapping, 
	return ret == 0 ? copied : ret;



      journal_error:

	reiserfs_write_unlock_once(inode->i_sb, lock_depth);

	reiserfs_write_unlock(inode->i_sb);

	locked = false;

	if (th) {

		if (!update_sd)
@@ -2813,10 +2808,11 @@ int reiserfs_commit_write(struct file *f, struct page *page, 
	int ret = 0;

	int update_sd = 0;

	struct reiserfs_transaction_handle *th = NULL;

	int depth;



	reiserfs_write_unlock(inode->i_sb);

	depth = reiserfs_write_unlock_nested(inode->i_sb);

	reiserfs_wait_on_write_block(inode->i_sb);

	reiserfs_write_lock(inode->i_sb);

	reiserfs_write_lock_nested(inode->i_sb, depth);



	if (reiserfs_transaction_running(inode->i_sb)) {

		th = current->journal_info;
@@ -3115,7 +3111,6 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) 
{

	struct inode *inode = dentry->d_inode;

	unsigned int ia_valid;

	int depth;

	int error;



	error = inode_change_ok(inode, attr);
@@ -3127,14 +3122,14 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) 


	if (is_quota_modification(inode, attr))

		dquot_initialize(inode);

	depth = reiserfs_write_lock_once(inode->i_sb);

	reiserfs_write_lock(inode->i_sb);

	if (attr->ia_valid & ATTR_SIZE) {

		/* version 2 items will be caught by the s_maxbytes check

		 ** done for us in vmtruncate

		 */

		if (get_inode_item_key_version(inode) == KEY_FORMAT_3_5 &&

		    attr->ia_size > MAX_NON_LFS) {

			reiserfs_write_unlock_once(inode->i_sb, depth);

			reiserfs_write_unlock(inode->i_sb);

			error = -EFBIG;

			goto out;

		}
@@ -3157,7 +3152,7 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) 
					error = err;

			}

			if (error) {

				reiserfs_write_unlock_once(inode->i_sb, depth);

				reiserfs_write_unlock(inode->i_sb);

				goto out;

			}

			/*
@@ -3167,7 +3162,7 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) 
			attr->ia_valid |= (ATTR_MTIME | ATTR_CTIME);

		}

	}

	reiserfs_write_unlock_once(inode->i_sb, depth);

	reiserfs_write_unlock(inode->i_sb);



	if ((((attr->ia_valid & ATTR_UID) && (from_kuid(&init_user_ns, attr->ia_uid) & ~0xffff)) ||

	     ((attr->ia_valid & ATTR_GID) && (from_kgid(&init_user_ns, attr->ia_gid) & ~0xffff))) &&
@@ -3192,16 +3187,16 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) 
			return error;



		/* (user+group)*(old+new) structure - we count quota info and , inode write (sb, inode) */

		depth = reiserfs_write_lock_once(inode->i_sb);

		reiserfs_write_lock(inode->i_sb);

		error = journal_begin(&th, inode->i_sb, jbegin_count);

		reiserfs_write_unlock_once(inode->i_sb, depth);

		reiserfs_write_unlock(inode->i_sb);

		if (error)

			goto out;

		error = dquot_transfer(inode, attr);

		depth = reiserfs_write_lock_once(inode->i_sb);

		reiserfs_write_lock(inode->i_sb);

		if (error) {

			journal_end(&th, inode->i_sb, jbegin_count);

			reiserfs_write_unlock_once(inode->i_sb, depth);

			reiserfs_write_unlock(inode->i_sb);

			goto out;

		}
@@ -3213,7 +3208,7 @@ int reiserfs_setattr(struct dentry *dentry, struct iattr *attr) 
			inode->i_gid = attr->ia_gid;

		mark_inode_dirty(inode);

		error = journal_end(&th, inode->i_sb, jbegin_count);

		reiserfs_write_unlock_once(inode->i_sb, depth);

		reiserfs_write_unlock(inode->i_sb);

		if (error)

			goto out;

	}

fs/reiserfs/ioctl.c

+3 −4
Original line number Diff line number Diff line
@@ -167,7 +167,6 @@ int reiserfs_commit_write(struct file *f, struct page *page, 
int reiserfs_unpack(struct inode *inode, struct file *filp)

{

	int retval = 0;

	int depth;

	int index;

	struct page *page;

	struct address_space *mapping;
@@ -183,11 +182,11 @@ int reiserfs_unpack(struct inode *inode, struct file *filp) 
		return 0;

	}



	depth = reiserfs_write_lock_once(inode->i_sb);



	/* we need to make sure nobody is changing the file size beneath us */

	reiserfs_mutex_lock_safe(&inode->i_mutex, inode->i_sb);



	reiserfs_write_lock(inode->i_sb);



	write_from = inode->i_size & (blocksize - 1);

	/* if we are on a block boundary, we are already unpacked.  */

	if (write_from == 0) {
@@ -221,6 +220,6 @@ int reiserfs_unpack(struct inode *inode, struct file *filp) 


      out:

	mutex_unlock(&inode->i_mutex);

	reiserfs_write_unlock_once(inode->i_sb, depth);

	reiserfs_write_unlock(inode->i_sb);

	return retval;

}