ext4: prepare to drop EXT4_STATE_DELALLOC_RESERVED

The EXT4_STATE_DELALLOC_RESERVED flag was originally implemented
because it was too hard to make sure the mballoc and get_block flags
could be reliably passed down through all of the codepaths that end up
calling ext4_mb_new_blocks().

Since then, we have mb_flags passed down through most of the code
paths, so getting rid of EXT4_STATE_DELALLOC_RESERVED isn't as tricky
as it used to.

This commit plumbs in the last of what is required, and then adds a
WARN_ON check to make sure we haven't missed anything.  If this passes
a full regression test run, we can then drop
EXT4_STATE_DELALLOC_RESERVED.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

1 files changed, 6 insertions, 4 deletions

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 8b0f9ef517d6..15dffdac5907 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4415,9 +4415,12 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
          * EDQUOT check, as blocks and quotas have been already
          * reserved when data being copied into pagecache.
          */
-        if (ext4_test_inode_state(ar->inode, EXT4_STATE_DELALLOC_RESERVED))
+        if (ext4_test_inode_state(ar->inode, EXT4_STATE_DELALLOC_RESERVED)) {
+                WARN_ON((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0);
                 ar->flags |= EXT4_MB_DELALLOC_RESERVED;
-        else {
+        }
+
+        if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) {
                 /* Without delayed allocation we need to verify
                  * there is enough free blocks to do block allocation
                  * and verify allocation doesn't exceed the quota limits.
@@ -4528,8 +4531,7 @@ out:
         if (inquota && ar->len < inquota)
                 dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len));
         if (!ar->len) {
-                if (!ext4_test_inode_state(ar->inode,
-                                           EXT4_STATE_DELALLOC_RESERVED))
+                if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0)
                         /* release all the reserved blocks if non delalloc */
                         percpu_counter_sub(&sbi->s_dirtyclusters_counter,
                                                 reserv_clstrs);