lkml.org 
[lkml]   [2007]   [Sep]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] ext34: ensure do_split leaves enough free space in both blocks
Eric Sandeen wrote:
> The do_split() function for htree dir blocks is intended to split a
> leaf block to make room for a new entry. It sorts the entries in the
> original block by hash value, then moves the last half of the entries to
> the new block - without accounting for how much space this actually moves.
> (IOW, it moves half of the entry *count* not half of the entry *space*).
> If by chance we have both large & small entries, and we move only the
> smallest entries, and we have a large new entry to insert, we may not have
> created enough space for it.

(btw, the upshot of this is that in add_dirent_to_buf(),
memcpy(de->name, name, namelen) will overshoot the buffer and actually
corrupt memory.)

:(

-Eric
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-09-17 19:25    [W:0.055 / U:0.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site