[52/90] ext4: discard preallocation when restarting a transaction during truncate

Greg KH
2009-12-11T04:40:23Z

[-- Attachment #1: 0052-ext4-discard-preallocation-when-restarting-a-transac.patch --]
[-- Type: text/plain, Size: 1376 bytes --]

2.6.31-stable review patch. If anyone has any objections, please let us know.

------------------
(cherry picked from commit fa5d11133b07053270e18fa9c18560e66e79217e)

When restart a transaction during a truncate operation, we drop and
reacquire i_data_sem. After reacquiring i_data_sem, we need to
discard any inode-based preallocation that might have been grabbed
while we released i_data_sem (for example, if pdflush is allocating
blocks and racing against the truncate).

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
fs/ext4/inode.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -193,7 +193,7 @@ static int try_to_extend_transaction(han
* so before we call here everything must be consistently dirtied against
* this transaction.
*/
- int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
+int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
int nblocks)
{
int ret;
@@ -209,6 +209,7 @@ static int try_to_extend_transaction(han
up_write(&EXT4_I(inode)->i_data_sem);
ret = ext4_journal_restart(handle, blocks_for_truncate(inode));
down_write(&EXT4_I(inode)->i_data_sem);
+ ext4_discard_preallocations(inode);

return ret;
}