Commit 55b55f3f authored Jun 08, 2023 by Theodore Ts'o Committed by Greg Kroah-Hartman Jun 14, 2023

ext4: only check dquot_initialize_needed() when debugging

commit dea9d8f7643fab07bf89a1155f1f94f37d096a5e upstream.

ext4_xattr_block_set() relies on its caller to call dquot_initialize()
on the inode.  To assure that this has happened there are WARN_ON
checks.  Unfortunately, this is subject to false positives if there is
an antagonist thread which is flipping the file system at high rates
between r/o and rw.  So only do the check if EXT4_XATTR_DEBUG is
enabled.

Link: https://lore.kernel.org/r/20230608044056.GA1418535@mit.edu


Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent b43c35da

fs/ext4/xattr.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -2041,8 +2041,9 @@ ext4_xattr_block_set(handle_t handle, struct inode inode,
		else {
		u32 ref;

		#ifdef EXT4_XATTR_DEBUG
		WARN_ON_ONCE(dquot_initialize_needed(inode));

		#endif
		/* The old block is released after updating
		the inode. */
		error = dquot_alloc_block(inode,
		@@ -2104,8 +2105,9 @@ ext4_xattr_block_set(handle_t handle, struct inode inode,
		/* We need to allocate a new block */
		ext4_fsblk_t goal, block;

		#ifdef EXT4_XATTR_DEBUG
		WARN_ON_ONCE(dquot_initialize_needed(inode));

		#endif
		goal = ext4_group_first_block_no(sb,
		EXT4_I(inode)->i_block_group);
		block = ext4_new_meta_blocks(handle, inode, goal, 0,