[PATCH 1/4] ext4: delalloc quota fixes

[Dmitry Monakhov <dmonakhov@openvz.org>]

This patch fix most visible problems with delalloc+quota issues
- ext4_get_reserved_space() must return bytes instead of blocks.
- Claim allocated meta blocks. Do it as we do for data blocks
  but delay it untill proper moment.
- Move space claiming to ext4_da_update_reserve_space()
  Only here we do know what we are dealing with data or metadata

The most useful test case for delalloc+quota is concurent tasks
with write+truncate vs chown for a same file.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
---
 fs/ext4/inode.c   |   12 ++++++++----
 fs/ext4/mballoc.c |    6 ------
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index ab22297..e642cdb 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1057,7 +1057,7 @@ qsize_t ext4_get_reserved_space(struct inode *inode)
 		EXT4_I(inode)->i_reserved_meta_blocks;
 	spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 
-	return total;
+	return (total << inode->i_blkbits);
 }
 /*
  * Calculate the number of metadata blocks need to reserve
@@ -1096,7 +1096,7 @@ static int ext4_calc_metadata_amount(struct inode *inode, int blocks)
 static void ext4_da_update_reserve_space(struct inode *inode, int used)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
-	int total, mdb, mdb_free;
+	int total, mdb, mdb_free, mdb_claim = 0;
 
 	spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
 	/* recalculate the number of metablocks still need to be reserved */
@@ -1109,7 +1109,9 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used)
 
 	if (mdb_free) {
 		/* Account for allocated meta_blocks */
-		mdb_free -= EXT4_I(inode)->i_allocated_meta_blocks;
+		mdb_claim = EXT4_I(inode)->i_allocated_meta_blocks;
+		BUG_ON(mdb_free < mdb_claim);
+		mdb_free -= mdb_claim;
 
 		/* update fs dirty blocks counter */
 		percpu_counter_sub(&sbi->s_dirtyblocks_counter, mdb_free);
@@ -1119,7 +1121,9 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used)
 
 	/* update per-inode reservations */
 	BUG_ON(used  > EXT4_I(inode)->i_reserved_data_blocks);
-	EXT4_I(inode)->i_reserved_data_blocks -= used;
+ 	EXT4_I(inode)->i_reserved_data_blocks -= used;
+	percpu_counter_sub(&sbi->s_dirtyblocks_counter, used + mdb_claim);
+	vfs_dq_claim_block(inode, used + mdb_claim);
 	spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 
 	/*
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index bba1282..d4c52db 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2750,12 +2750,6 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
 	if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
 		/* release all the reserved blocks if non delalloc */
 		percpu_counter_sub(&sbi->s_dirtyblocks_counter, reserv_blks);
-	else {
-		percpu_counter_sub(&sbi->s_dirtyblocks_counter,
-						ac->ac_b_ex.fe_len);
-		/* convert reserved quota blocks to real quota blocks */
-		vfs_dq_claim_block(ac->ac_inode, ac->ac_b_ex.fe_len);
-	}
 
 	if (sbi->s_log_groups_per_flex) {
 		ext4_group_t flex_group = ext4_flex_group(sbi,
-- 
1.6.0.4