Commit 44fb851d authored by Zheng Liu's avatar Zheng Liu Committed by Theodore Ts'o
Browse files

ext4: add WARN_ON to check the length of allocated blocks 



In commit 921f266b: ext4: add self-testing infrastructure to do a
sanity check, some sanity checks were added in map_blocks to make sure
'retval == map->m_len'.

Enable these checks by default and report any assertion failures using
ext4_warning() and WARN_ON() since they can help us to figure out some
bugs that are otherwise hard to hit.

Signed-off-by: default avatarZheng Liu <wenqing.lz@taobao.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 94eec0fc

fs/ext4/inode.c

+18 −21
Original line number Diff line number Diff line
@@ -555,14 +555,13 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, 
		int ret;

		unsigned long long status;



#ifdef ES_AGGRESSIVE_TEST

		if (retval != map->m_len) {

			printk("ES len assertion failed for inode: %lu "

			       "retval %d != map->m_len %d "

			       "in %s (lookup)\n", inode->i_ino, retval,

			       map->m_len, __func__);

		if (unlikely(retval != map->m_len)) {

			ext4_warning(inode->i_sb,

				     "ES len assertion failed for inode "

				     "%lu: retval %d != map->m_len %d",

				     inode->i_ino, retval, map->m_len);

			WARN_ON(1);

		}

#endif



		status = map->m_flags & EXT4_MAP_UNWRITTEN ?

				EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
@@ -656,14 +655,13 @@ found: 
		int ret;

		unsigned long long status;



#ifdef ES_AGGRESSIVE_TEST

		if (retval != map->m_len) {

			printk("ES len assertion failed for inode: %lu "

			       "retval %d != map->m_len %d "

			       "in %s (allocation)\n", inode->i_ino, retval,

			       map->m_len, __func__);

		if (unlikely(retval != map->m_len)) {

			ext4_warning(inode->i_sb,

				     "ES len assertion failed for inode "

				     "%lu: retval %d != map->m_len %d",

				     inode->i_ino, retval, map->m_len);

			WARN_ON(1);

		}

#endif



		/*

		 * If the extent has been zeroed out, we don't need to update
@@ -1637,14 +1635,13 @@ add_delayed: 
		int ret;

		unsigned long long status;



#ifdef ES_AGGRESSIVE_TEST

		if (retval != map->m_len) {

			printk("ES len assertion failed for inode: %lu "

			       "retval %d != map->m_len %d "

			       "in %s (lookup)\n", inode->i_ino, retval,

			       map->m_len, __func__);

		if (unlikely(retval != map->m_len)) {

			ext4_warning(inode->i_sb,

				     "ES len assertion failed for inode "

				     "%lu: retval %d != map->m_len %d",

				     inode->i_ino, retval, map->m_len);

			WARN_ON(1);

		}

#endif



		status = map->m_flags & EXT4_MAP_UNWRITTEN ?

				EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;

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