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SubjectRe: [Bug 417] New: htree much slower than regular ext3
FromAlex Tomas <>
Date09 Mar 2003 10:08:34 +0300
>>>>> Daniel Phillips (DP) writes:

DP> On Fri 07 Mar 03 16:46, Alex Tomas wrote:
DP> The problem I see with your approach is that the traversal is no DP> longer in hash order, so a leaf split in the middle of a DP> directory traversal could result in a lot of duplicate dirents. DP> I'm not sure there's a way around that.

1) As far as I understand, duplicates are possible even in classic ext2 w/o sortdir/index. See the diagram:

Process 1 Process 2

getdents(2) returns
dentry1 (file1 -> Inode1)
dentry2 (file2 -> Inode2)

context switch -->
unlink(file1), empty dentry1
creat(file3), Inode3, use dentry1
creat(file1), Inode1, use dentry3

context switch -->

getdents(2) returns
dentry3(file1 -> Inode1)


Am I right?


2) Why do not use hash order for traversal like ext3_dx_readdir() does? Upon reading several dentries within some hash set readdir() sorts them in inode order and returns to an user.


with best regards, Alex

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