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Commit d3d1faf6 authored by Curt Wohlgemuth's avatar Curt Wohlgemuth Committed by Theodore Ts'o
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ext4: Handle nested ext4_journal_start/stop calls without a journal 



This patch fixes a problem with handling nested calls to
ext4_journal_start/ext4_journal_stop, when there is no journal present.

Signed-off-by: default avatarCurt Wohlgemuth <curtw@google.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent f3dc272f

fs/ext4/ext4_jbd2.h

+4 −2
Original line number Original line Diff line number Diff line
@@ -161,11 +161,13 @@ int __ext4_handle_dirty_metadata(const char *where, handle_t *handle, 
handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);

handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);

int __ext4_journal_stop(const char *where, handle_t *handle);

int __ext4_journal_stop(const char *where, handle_t *handle);





#define EXT4_NOJOURNAL_HANDLE	((handle_t *) 0x1)

#define EXT4_NOJOURNAL_MAX_REF_COUNT ((unsigned long) 4096)





/* Note:  Do not use this for NULL handles.  This is only to determine if

 * a properly allocated handle is using a journal or not. */

static inline int ext4_handle_valid(handle_t *handle)

static inline int ext4_handle_valid(handle_t *handle)

{

{

	if (handle == EXT4_NOJOURNAL_HANDLE)

	if ((unsigned long)handle < EXT4_NOJOURNAL_MAX_REF_COUNT)

		return 0;

		return 0;

	return 1;

	return 1;

}

}

fs/ext4/namei.c

+2 −1
Original line number Original line Diff line number Diff line
@@ -2076,7 +2076,8 @@ int ext4_orphan_del(handle_t *handle, struct inode *inode) 
	struct ext4_iloc iloc;

	struct ext4_iloc iloc;

	int err = 0;

	int err = 0;





	if (!ext4_handle_valid(handle))

	/* ext4_handle_valid() assumes a valid handle_t pointer */

	if (handle && !ext4_handle_valid(handle))

		return 0;

		return 0;





	mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);

	mutex_lock(&EXT4_SB(inode->i_sb)->s_orphan_lock);

fs/ext4/super.c

+32 −10
Original line number Original line Diff line number Diff line
@@ -189,6 +189,36 @@ void ext4_itable_unused_set(struct super_block *sb, 
		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);

		bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);

}

}







/* Just increment the non-pointer handle value */

static handle_t *ext4_get_nojournal(void)

{

	handle_t *handle = current->journal_info;

	unsigned long ref_cnt = (unsigned long)handle;



	BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);



	ref_cnt++;

	handle = (handle_t *)ref_cnt;



	current->journal_info = handle;

	return handle;

}





/* Decrement the non-pointer handle value */

static void ext4_put_nojournal(handle_t *handle)

{

	unsigned long ref_cnt = (unsigned long)handle;



	BUG_ON(ref_cnt == 0);



	ref_cnt--;

	handle = (handle_t *)ref_cnt;



	current->journal_info = handle;

}



/*

/*

 * Wrappers for jbd2_journal_start/end.

 * Wrappers for jbd2_journal_start/end.

 *

 *
@@ -215,11 +245,7 @@ handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks) 
		}

		}

		return jbd2_journal_start(journal, nblocks);

		return jbd2_journal_start(journal, nblocks);

	}

	}

	/*

	return ext4_get_nojournal();

	 * We're not journaling, return the appropriate indication.

	 */

	current->journal_info = EXT4_NOJOURNAL_HANDLE;

	return current->journal_info;

}

}





/*

/*
@@ -235,11 +261,7 @@ int __ext4_journal_stop(const char *where, handle_t *handle) 
	int rc;

	int rc;





	if (!ext4_handle_valid(handle)) {

	if (!ext4_handle_valid(handle)) {

		/*

		ext4_put_nojournal(handle);

		 * Do this here since we don't call jbd2_journal_stop() in

		 * no-journal mode.

		 */

		current->journal_info = NULL;

		return 0;

		return 0;

	}

	}

	sb = handle->h_transaction->t_journal->j_private;

	sb = handle->h_transaction->t_journal->j_private;