ext4: add EXT4_IOC_ALLOC_DA_BLKS ioctl

Add an ioctl which forces all of the delay allocated blocks to be
allocated.  This also provides a function ext4_alloc_da_blocks() which
will be used by the following commits to force files to be fully
allocated to preserve application-expected ext3 behaviour.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 096456c8559b..b0ea70cc94db 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -317,7 +317,9 @@ struct ext4_new_group_data {
 #define EXT4_IOC_GROUP_EXTEND           _IOW('f', 7, unsigned long)
 #define EXT4_IOC_GROUP_ADD              _IOW('f', 8, struct ext4_new_group_input)
 #define EXT4_IOC_MIGRATE                _IO('f', 9)
+ /* note ioctl 10 reserved for an early version of the FIEMAP ioctl */
  /* note ioctl 11 reserved for filesystem-independent FIEMAP ioctl */
+#define EXT4_IOC_ALLOC_DA_BLKS          _IO('f', 12)
 
 /*
  * ioctl commands in 32 bit emulation
@@ -1094,6 +1096,7 @@ extern int ext4_can_truncate(struct inode *inode);
 extern void ext4_truncate(struct inode *);
 extern void ext4_set_inode_flags(struct inode *);
 extern void ext4_get_inode_flags(struct ext4_inode_info *);
+extern int ext4_alloc_da_blocks(struct inode *inode);
 extern void ext4_set_aops(struct inode *inode);
 extern int ext4_writepage_trans_blocks(struct inode *);
 extern int ext4_meta_trans_blocks(struct inode *, int nrblocks, int idxblocks);