ext4: Automatically allocate delay allocated blocks on close

(cherry picked from commit 7d8f9f7d150dded7b68e61ca6403a1f166fb4edf)

When closing a file that had been previously truncated, force any
delay allocated blocks that to be allocated so that if the filesystem
is mounted with data=ordered, the data blocks will be pushed out to
disk along with the journal commit.  Many application programs expect
this, so we do this to avoid zero length files if the system crashes
unexpectedly.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index f5552d7c661e7a6087ad370fb48efb8b13cb7693..83f685da8bea82f908c31164b94b1de6d36a6fc9 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -279,6 +279,7 @@ static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
 #define EXT4_STATE_NEW                 0x00000002 /* inode is newly created */
 #define EXT4_STATE_XATTR               0x00000004 /* has in-inode xattrs */
 #define EXT4_STATE_NO_EXPAND           0x00000008 /* No space for expansion */
+#define EXT4_STATE_DA_ALLOC_CLOSE      0x00000010 /* Alloc DA blks on close */
 
 /* Used to pass group descriptor data when online resize is done */
 struct ext4_new_group_input {

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index f731cb545a0359cc664de79a3fe9ab6c7ca4f3b8..06df8272c63964c39330367ca791a0d32bbbe62d 100644 (file)
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -33,6 +33,10 @@
  */
 static int ext4_release_file(struct inode *inode, struct file *filp)
 {
+       if (EXT4_I(inode)->i_state & EXT4_STATE_DA_ALLOC_CLOSE) {
+               ext4_alloc_da_blocks(inode);
+               EXT4_I(inode)->i_state &= ~EXT4_STATE_DA_ALLOC_CLOSE;
+       }
        /* if we are the last writer on the inode, drop the block reservation */
        if ((filp->f_mode & FMODE_WRITE) &&
                        (atomic_read(&inode->i_writecount) == 1))

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 76969f74745268946625ccbe5ee3d735a363cf85..afb3ea2d1cf335b8c808f8457bbd96f98c06d16e 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -3880,6 +3880,9 @@ void ext4_truncate(struct inode *inode)
        if (!ext4_can_truncate(inode))
                return;
 
+       if (inode->i_size == 0)
+               ei->i_state |= EXT4_STATE_DA_ALLOC_CLOSE;
+
        if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
                ext4_ext_truncate(inode);
                return;