ext4: Fix potential quota deadlock

[net-next-2.6.git] / fs / ext4 / inode.c

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 5352db1a3086a075f777652b1ac496a1f2c84aaa..ddd0a9c87d9eef7d3c3dd8e8b9d4cc85b4f43ed7 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1003,17 +1003,12 @@ out:
        return err;
 }
 
-qsize_t ext4_get_reserved_space(struct inode *inode)
+#ifdef CONFIG_QUOTA
+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 << inode->i_blkbits);
+       return &EXT4_I(inode)->i_reserved_quota;
 }
+#endif
 /*
  * Calculate the number of metadata blocks need to reserve
  * to allocate @blocks for non extent file based file
@@ -1051,7 +1046,7 @@ 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 */
@@ -1064,7 +1059,9 @@ 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);
@@ -1075,8 +1072,11 @@ 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;
+       percpu_counter_sub(&sbi->s_dirtyblocks_counter, used + mdb_claim);
        spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
 
+       vfs_dq_claim_block(inode, used + mdb_claim);
+
        /*
         * free those over-booking quota for metadata blocks
         */
@@ -4794,6 +4794,9 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
                        ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
        inode->i_size = ext4_isize(raw_inode);
        ei->i_disksize = inode->i_size;
+#ifdef CONFIG_QUOTA
+       ei->i_reserved_quota = 0;
+#endif
        inode->i_generation = le32_to_cpu(raw_inode->i_generation);
        ei->i_block_group = iloc.block_group;
        ei->i_last_alloc_group = ~0;