From: "Peter Teoh"
Subject: Re: ext2_block_alloc_info
Date: Sun, 21 Dec 2008 09:25:45 +0800
Message-ID: <804dabb00812201725r304bed36ufc56ebc2393e2299@mail.gmail.com>
References: <2d08ef090812200743o47cd4abdwd9915653f6f4f3f7@mail.gmail.com>
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Cc: Kernelnewbies ,
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To: "Rohit Sharma"
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On Sat, Dec 20, 2008 at 11:43 PM, Rohit Sharma wrote:
> A little confusion.
>
> Just refer this structure in linux/ext2_fs_sb.h
>
> struct ext2_block_alloc_info {
> 46 /* information about reservation window */
> 47 struct ext2_reserve_window_node rsv_window_node;
> 48 /*
> 49 * was i_next_alloc_block in ext2_inode_info
> 50 * is the logical (file-relative) number of the
> 51 * most-recently-allocated block in this file.
> 52 * We use this for detecting linearly ascending allocation requests.
> 53 */
> 54 __u32 last_alloc_logical_block;
if i interpret the meaning of "file-relative logical number"
correctly, and since one-file-one-inode concept, then it means that it
should mean inode-relative logical block number.
> 55 /*
> 56 * Was i_next_alloc_goal in ext2_inode_info
> 57 * is the *physical* companion to i_next_alloc_block.
> 58 * it the the physical block number of the block which was
> inode1 has logical blocks 0 1 2 , physical 22 23 24
> inode2 has logical blocks 0 1 2 , physical 34 35 50
>
as per comment above, the sequence above looks likely, but then this
is my guess again.
--
Regards,
Peter Teoh
Ernest Hemingway - "Never mistake motion for action."