On Thu, May 05, 2005 at 06:05:52PM -0700, Harsha Srinath wrote:
> I am trying to port a ext3 cow utility from 2.4 to 2.6. I have a
> couple of questions regarding changes in fs.h and fsfilter.h that were
> in 2.4.
I hope you are aware that there Jörn Engel did a "cowlinks" patch for
2.6.4 about a year ago? Search a linux-kernel archive for the subject
"[PATCH] cowlinks v2" or the Message-ID
"<20040320083411.GA25934@xxxxxxxxxxxxxxxxxxxx>" . The patch is pretty
small.
> 1. In the the 2.4 ../include/linux/fs.h file, there is a union in the
> VFS inode struct like :-
> struct inode {
> struct list_head i_hash;
> struct list_head i_list;
> struct list_head i_dentry;
> ........
> union {
> struct minix_inode_info minix_i;
> struct ext2_inode_info ext2_i;
> struct ext3_inode_info ext3_i;
> .......
> }u;
>
> Can anyone tell me where this union info is present in 2.6.10 ? I
> grep'ed in the ..../include/linux/ directory but could not find the
> union in any VFS files. (I want the VFS to know my changed ext3 inode
> info that I call "struct extcow3_inode_info extcow3_i".)
Al Viro removed it because this struct made it a pain to use
out-of-tree filesystems. It's replaced with the generic_ip pointer.
I remember cause I did a proof-of-concept patch for a filesystem
(iso9660, IIRC).
> I guess the same answer would hold good for :-
> struct super_block {
> struct list_head s_list; /* Keep this first */
> kdev_t s_dev;
> unsigned long s_blocksize;
> unsigned char s_blocksize_bits;
> .........
> union {
> struct minix_sb_info minix_sb;
> struct ext2_sb_info ext2_sb;
> struct ext3_sb_info ext3_sb;
> ...............
> }u;
Same here: hard to use out-of-tree filesystems.
> 2. I am unable to find the following #defines :-
> #define FILTER_FS_TYPES 6
> #define FILTER_FS_EXT2 0
> #define FILTER_FS_EXT3 1
> ....................
> that were earlier in ../include/linux/fsfilter.h in the 2.4 kernel.
Don't know, and also don't know what they were used for. I'd say the
filters are for the VFS, not for individual filesystems.
Erik
--
Erik Mouw
J.A.K.Mouw@xxxxxxxxxxxxxx mouw@xxxxxxxxxxxx
Attachment:
signature.asc
Description: Digital signature
