ext4: Properly update i_disksize.

With delayed allocation we use i_data_sem to update i_disksize.  We need
to update i_disksize only if the new size specified is greater than the
current value and we need to make sure we don't race with other
i_disksize update.  With delayed allocation we will switch to the
write_begin function for non-delayed allocation if we are low on free
blocks.  This means the write_begin function for non-delayed allocation
also needs to use the same locking.

We also need to check and update i_disksize even if the new size is less
that inode.i_size because of delayed allocation.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Aneesh Kumar K.V
2008-09-13 13:06:18 -04:00
committed by Theodore Ts'o
parent ae4d537211
commit cf17fea657
3 changed files with 46 additions and 28 deletions

View File

@@ -1218,6 +1218,17 @@ do { \
#define EXT4_FREEBLOCKS_WATERMARK 0
#endif
static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
{
/*
* XXX: replace with spinlock if seen contended -bzzz
*/
down_write(&EXT4_I(inode)->i_data_sem);
if (newsize > EXT4_I(inode)->i_disksize)
EXT4_I(inode)->i_disksize = newsize;
up_write(&EXT4_I(inode)->i_data_sem);
return ;
}
/*
* Inodes and files operations