ext4: quota reservation for delayed allocation
Uses quota reservation/claim/release to handle quota properly for delayed
allocation in the three steps: 1) quotas are reserved when data being copied
to cache when block allocation is defered 2) when new blocks are allocated.
reserved quotas are converted to the real allocated quota, 2) over-booked
quotas for metadata blocks are released back.
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index c7fed5b..8290cfb 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -975,6 +975,17 @@
return err;
}
+qsize_t ext4_get_reserved_space(struct inode *inode)
+{
+ unsigned long long total;
+
+ spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
+ total = EXT4_I(inode)->i_reserved_data_blocks +
+ EXT4_I(inode)->i_reserved_meta_blocks;
+ spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+
+ return total;
+}
/*
* Calculate the number of metadata blocks need to reserve
* to allocate @blocks for non extent file based file
@@ -1036,8 +1047,14 @@
/* update per-inode reservations */
BUG_ON(used > EXT4_I(inode)->i_reserved_data_blocks);
EXT4_I(inode)->i_reserved_data_blocks -= used;
-
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+
+ /*
+ * free those over-booking quota for metadata blocks
+ */
+
+ if (mdb_free)
+ vfs_dq_release_reservation_block(inode, mdb_free);
}
/*
@@ -1553,8 +1570,8 @@
static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
{
int retries = 0;
- struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
- unsigned long md_needed, mdblocks, total = 0;
+ struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+ unsigned long md_needed, mdblocks, total = 0;
/*
* recalculate the amount of metadata blocks to reserve
@@ -1570,12 +1587,23 @@
md_needed = mdblocks - EXT4_I(inode)->i_reserved_meta_blocks;
total = md_needed + nrblocks;
+ /*
+ * Make quota reservation here to prevent quota overflow
+ * later. Real quota accounting is done at pages writeout
+ * time.
+ */
+ if (vfs_dq_reserve_block(inode, total)) {
+ spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+ return -EDQUOT;
+ }
+
if (ext4_claim_free_blocks(sbi, total)) {
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
yield();
goto repeat;
}
+ vfs_dq_release_reservation_block(inode, total);
return -ENOSPC;
}
EXT4_I(inode)->i_reserved_data_blocks += nrblocks;
@@ -1629,6 +1657,8 @@
BUG_ON(mdb > EXT4_I(inode)->i_reserved_meta_blocks);
EXT4_I(inode)->i_reserved_meta_blocks = mdb;
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
+
+ vfs_dq_release_reservation_block(inode, release);
}
static void ext4_da_page_release_reservation(struct page *page,