ext4_inode_info.i_ext_generation isn't used by anything. Was there an
intent to use it for something in the future?
- Ted
commit 51972792db1397cddd97e1ab9c8d2604453f5b4c
Author: Theodore Ts'o <[email protected]>
Date: Tue Nov 4 18:46:03 2008 -0500
ext4: Remove i_ext_generation from ext4_inode_info structure
The i_ext_generation was incremented, but never used. Remove it to
slim down the ext4_inode_info structure.
Signed-off-by: "Theodore Ts'o" <[email protected]>
diff --git a/fs/ext4/ext4_extents.h b/fs/ext4/ext4_extents.h
index bec7ce5..18cb67b 100644
--- a/fs/ext4/ext4_extents.h
+++ b/fs/ext4/ext4_extents.h
@@ -194,11 +194,6 @@ static inline unsigned short ext_depth(struct inode *inode)
return le16_to_cpu(ext_inode_hdr(inode)->eh_depth);
}
-static inline void ext4_ext_tree_changed(struct inode *inode)
-{
- EXT4_I(inode)->i_ext_generation++;
-}
-
static inline void
ext4_ext_invalidate_cache(struct inode *inode)
{
diff --git a/fs/ext4/ext4_i.h b/fs/ext4/ext4_i.h
index 5c124c0..acc0b72 100644
--- a/fs/ext4/ext4_i.h
+++ b/fs/ext4/ext4_i.h
@@ -117,7 +117,6 @@ struct ext4_inode_info {
struct inode vfs_inode;
struct jbd2_inode jinode;
- unsigned long i_ext_generation;
struct ext4_ext_cache i_cached_extent;
/*
* File creation time. Its function is same as that of
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index ea2ce3c..501952f 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1622,7 +1622,6 @@ cleanup:
ext4_ext_drop_refs(npath);
kfree(npath);
}
- ext4_ext_tree_changed(inode);
ext4_ext_invalidate_cache(inode);
return err;
}
@@ -2233,7 +2232,6 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
}
}
out:
- ext4_ext_tree_changed(inode);
ext4_ext_drop_refs(path);
kfree(path);
ext4_journal_stop(handle);
On Nov 04, 2008 18:47 -0500, Theodore Ts'o wrote:
> ext4_inode_info.i_ext_generation isn't used by anything. Was there an
> intent to use it for something in the future?
Alex was going to use this at one point in the future, but it never
happened.
Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.
Andreas Dilger wrote:
> On Nov 04, 2008 18:47 -0500, Theodore Ts'o wrote:
>> ext4_inode_info.i_ext_generation isn't used by anything. Was there an
>> intent to use it for something in the future?
>
> Alex was going to use this at one point in the future, but it never
> happened.
actually it was used by delayed allocation patch as walk_space() takes
truncate_sem, then, if block isn't allocated yet, start transaction which
we can't do holding truncate_sem. so the idea is to release truncate_sem,
start transaction, then acquire truncate_sem. but in this window the tree
can change making path structure obsolete. either we check tree hasn't
changed or use generation to avoid unneeded path revalidation?
thanks, Alex