Commit 41a5b913 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

jbd2: invalidate handle if jbd2_journal_restart() fails 



If jbd2_journal_restart() fails the handle will have been disconnected
from the current transaction.  In this situation, the handle must not
be used for for any jbd2 function other than jbd2_journal_stop().
Enforce this with by treating a handle which has a NULL transaction
pointer as an aborted handle, and issue a kernel warning if
jbd2_journal_extent(), jbd2_journal_get_write_access(),
jbd2_journal_dirty_metadata(), etc. is called with an invalid handle.

This commit also fixes a bug where jbd2_journal_stop() would trip over
a kernel jbd2 assertion check when trying to free an invalid handle.

Also move the responsibility of setting current->journal_info to
start_this_handle(), simplifying the three users of this function.

Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
Reported-by: default avatarYounger Liu <younger.liu@huawei.com>
Cc: Jan Kara <jack@suse.cz>
parent 21ddd568

fs/jbd2/transaction.c

+43 −31
Original line number Diff line number Diff line
@@ -368,6 +368,7 @@ repeat: 
		  atomic_read(&transaction->t_outstanding_credits),

		  jbd2_log_space_left(journal));

	read_unlock(&journal->j_state_lock);

	current->journal_info = handle;



	lock_map_acquire(&handle->h_lockdep_map);

	jbd2_journal_free_transaction(new_transaction);
@@ -442,14 +443,11 @@ handle_t *jbd2__journal_start(journal_t *journal, int nblocks, int rsv_blocks, 
		handle->h_rsv_handle = rsv_handle;

	}



	current->journal_info = handle;



	err = start_this_handle(journal, handle, gfp_mask);

	if (err < 0) {

		if (handle->h_rsv_handle)

			jbd2_free_handle(handle->h_rsv_handle);

		jbd2_free_handle(handle);

		current->journal_info = NULL;

		return ERR_PTR(err);

	}

	handle->h_type = type;
@@ -511,16 +509,13 @@ int jbd2_journal_start_reserved(handle_t *handle, unsigned int type, 
	}



	handle->h_journal = NULL;

	current->journal_info = handle;

	/*

	 * GFP_NOFS is here because callers are likely from writeback or

	 * similarly constrained call sites

	 */

	ret = start_this_handle(journal, handle, GFP_NOFS);

	if (ret < 0) {

		current->journal_info = NULL;

	if (ret < 0)

		jbd2_journal_free_reserved(handle);

	}

	handle->h_type = type;

	handle->h_line_no = line_no;

	return ret;
@@ -550,20 +545,21 @@ EXPORT_SYMBOL(jbd2_journal_start_reserved); 
int jbd2_journal_extend(handle_t *handle, int nblocks)

{

	transaction_t *transaction = handle->h_transaction;

	journal_t *journal = transaction->t_journal;

	journal_t *journal;

	int result;

	int wanted;



	result = -EIO;

	WARN_ON(!transaction);

	if (is_handle_aborted(handle))

		goto out;

		return -EROFS;

	journal = transaction->t_journal;



	result = 1;



	read_lock(&journal->j_state_lock);



	/* Don't extend a locked-down transaction! */

	if (handle->h_transaction->t_state != T_RUNNING) {

	if (transaction->t_state != T_RUNNING) {

		jbd_debug(3, "denied handle %p %d blocks: "

			  "transaction not running\n", handle, nblocks);

		goto error_out;
@@ -589,7 +585,7 @@ int jbd2_journal_extend(handle_t *handle, int nblocks) 
	}



	trace_jbd2_handle_extend(journal->j_fs_dev->bd_dev,

				 handle->h_transaction->t_tid,

				 transaction->t_tid,

				 handle->h_type, handle->h_line_no,

				 handle->h_buffer_credits,

				 nblocks);
@@ -603,7 +599,6 @@ unlock: 
	spin_unlock(&transaction->t_handle_lock);

error_out:

	read_unlock(&journal->j_state_lock);

out:

	return result;

}
@@ -626,14 +621,16 @@ out: 
int jbd2__journal_restart(handle_t *handle, int nblocks, gfp_t gfp_mask)

{

	transaction_t *transaction = handle->h_transaction;

	journal_t *journal = transaction->t_journal;

	journal_t *journal;

	tid_t		tid;

	int		need_to_start, ret;



	WARN_ON(!transaction);

	/* If we've had an abort of any type, don't even think about

	 * actually doing the restart! */

	if (is_handle_aborted(handle))

		return 0;

	journal = transaction->t_journal;



	/*

	 * First unlink the handle from its current transaction, and start the
@@ -654,6 +651,8 @@ int jbd2__journal_restart(handle_t *handle, int nblocks, gfp_t gfp_mask) 
		wake_up(&journal->j_wait_updates);

	tid = transaction->t_tid;

	spin_unlock(&transaction->t_handle_lock);

	handle->h_transaction = NULL;

	current->journal_info = NULL;



	jbd_debug(2, "restarting handle %p\n", handle);

	need_to_start = !tid_geq(journal->j_commit_request, tid);
@@ -783,17 +782,16 @@ do_get_write_access(handle_t *handle, struct journal_head *jh, 
			int force_copy)

{

	struct buffer_head *bh;

	transaction_t *transaction;

	transaction_t *transaction = handle->h_transaction;

	journal_t *journal;

	int error;

	char *frozen_buffer = NULL;

	int need_copy = 0;

	unsigned long start_lock, time_lock;



	WARN_ON(!transaction);

	if (is_handle_aborted(handle))

		return -EROFS;



	transaction = handle->h_transaction;

	journal = transaction->t_journal;



	jbd_debug(5, "journal_head %p, force_copy %d\n", jh, force_copy);
@@ -1052,14 +1050,16 @@ int jbd2_journal_get_write_access(handle_t *handle, struct buffer_head *bh) 
int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh)

{

	transaction_t *transaction = handle->h_transaction;

	journal_t *journal = transaction->t_journal;

	journal_t *journal;

	struct journal_head *jh = jbd2_journal_add_journal_head(bh);

	int err;



	jbd_debug(5, "journal_head %p\n", jh);

	WARN_ON(!transaction);

	err = -EROFS;

	if (is_handle_aborted(handle))

		goto out;

	journal = transaction->t_journal;

	err = 0;



	JBUFFER_TRACE(jh, "entry");
@@ -1265,12 +1265,14 @@ void jbd2_buffer_abort_trigger(struct journal_head *jh, 
int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh)

{

	transaction_t *transaction = handle->h_transaction;

	journal_t *journal = transaction->t_journal;

	journal_t *journal;

	struct journal_head *jh;

	int ret = 0;



	WARN_ON(!transaction);

	if (is_handle_aborted(handle))

		goto out;

		return -EROFS;

	journal = transaction->t_journal;

	jh = jbd2_journal_grab_journal_head(bh);

	if (!jh) {

		ret = -EUCLEAN;
@@ -1364,7 +1366,7 @@ int jbd2_journal_dirty_metadata(handle_t *handle, struct buffer_head *bh) 


	JBUFFER_TRACE(jh, "file as BJ_Metadata");

	spin_lock(&journal->j_list_lock);

	__jbd2_journal_file_buffer(jh, handle->h_transaction, BJ_Metadata);

	__jbd2_journal_file_buffer(jh, transaction, BJ_Metadata);

	spin_unlock(&journal->j_list_lock);

out_unlock_bh:

	jbd_unlock_bh_state(bh);
@@ -1395,12 +1397,17 @@ out: 
int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh)

{

	transaction_t *transaction = handle->h_transaction;

	journal_t *journal = transaction->t_journal;

	journal_t *journal;

	struct journal_head *jh;

	int drop_reserve = 0;

	int err = 0;

	int was_modified = 0;



	WARN_ON(!transaction);

	if (is_handle_aborted(handle))

		return -EROFS;

	journal = transaction->t_journal;



	BUFFER_TRACE(bh, "entry");



	jbd_lock_bh_state(bh);
@@ -1427,7 +1434,7 @@ int jbd2_journal_forget (handle_t *handle, struct buffer_head *bh) 
	 */

	jh->b_modified = 0;



	if (jh->b_transaction == handle->h_transaction) {

	if (jh->b_transaction == transaction) {

		J_ASSERT_JH(jh, !jh->b_frozen_data);



		/* If we are forgetting a buffer which is already part
@@ -1522,19 +1529,21 @@ drop: 
int jbd2_journal_stop(handle_t *handle)

{

	transaction_t *transaction = handle->h_transaction;

	journal_t *journal = transaction->t_journal;

	int err, wait_for_commit = 0;

	journal_t *journal;

	int err = 0, wait_for_commit = 0;

	tid_t tid;

	pid_t pid;



	if (!transaction)

		goto free_and_exit;

	journal = transaction->t_journal;



	J_ASSERT(journal_current_handle() == handle);



	if (is_handle_aborted(handle))

		err = -EIO;

	else {

	else

		J_ASSERT(atomic_read(&transaction->t_updates) > 0);

		err = 0;

	}



	if (--handle->h_ref > 0) {

		jbd_debug(4, "h_ref %d -> %d\n", handle->h_ref + 1,
@@ -1544,7 +1553,7 @@ int jbd2_journal_stop(handle_t *handle) 


	jbd_debug(4, "Handle %p going down\n", handle);

	trace_jbd2_handle_stats(journal->j_fs_dev->bd_dev,

				handle->h_transaction->t_tid,

				transaction->t_tid,

				handle->h_type, handle->h_line_no,

				jiffies - handle->h_start_jiffies,

				handle->h_sync, handle->h_requested_credits,
@@ -1657,6 +1666,7 @@ int jbd2_journal_stop(handle_t *handle) 


	if (handle->h_rsv_handle)

		jbd2_journal_free_reserved(handle->h_rsv_handle);

free_and_exit:

	jbd2_free_handle(handle);

	return err;

}
@@ -2362,10 +2372,12 @@ void jbd2_journal_refile_buffer(journal_t *journal, struct journal_head *jh) 
int jbd2_journal_file_inode(handle_t *handle, struct jbd2_inode *jinode)

{

	transaction_t *transaction = handle->h_transaction;

	journal_t *journal = transaction->t_journal;

	journal_t *journal;



	WARN_ON(!transaction);

	if (is_handle_aborted(handle))

		return -EIO;

		return -EROFS;

	journal = transaction->t_journal;



	jbd_debug(4, "Adding inode %lu, tid:%d\n", jinode->i_vfs_inode->i_ino,

			transaction->t_tid);

include/linux/jbd2.h

+1 −1
Original line number Diff line number Diff line
@@ -1266,7 +1266,7 @@ static inline int is_journal_aborted(journal_t *journal) 


static inline int is_handle_aborted(handle_t *handle)

{

	if (handle->h_aborted)

	if (handle->h_aborted || !handle->h_transaction)

		return 1;

	return is_journal_aborted(handle->h_transaction->t_journal);

}

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