ext4: only check dquot_initialize_needed() when debugging

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>

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 13d7f17a9c8cce74442e07aa1c67adb2133c737c..321e3a888c20bf26880debed2d8374cdb01c2a7d 100644 (file)
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -2056,8 +2056,9 @@ 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,
@@ -2120,8 +2121,9 @@ 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,