Author: wmb Date: 2007-08-01 05:11:46 +0200 (Wed, 01 Aug 2007) New Revision: 507
Modified: ofw/fs/fatfs/bpb.fth ofw/fs/fatfs/fat.fth Log: FAT filesystem - OLPC trac 2609. Fixed FAT32 cluster allocation bug. The "next cluster" field in the fsinfo structure was being treated as a definitive free cluster number, instead of as a hint for where to begin searching. In addition, it was off by one - that field typically contains the number of the most recently written cluster, whereas the code was treating it as the next available cluster number.
Modified: ofw/fs/fatfs/bpb.fth =================================================================== --- ofw/fs/fatfs/bpb.fth 2007-07-30 21:08:57 UTC (rev 506) +++ ofw/fs/fatfs/bpb.fth 2007-08-01 03:11:46 UTC (rev 507) @@ -91,21 +91,11 @@ d# 16 constant fat16 d# 32 constant fat32
-: fs-lelop ( adr op -- ) - fsinfo @ 0<> if - over lel@ swap execute swap lel! - true fsinfos-dirty c! - else - 2drop - then -; -: fs-free#+ ( -- ) fs_freecluster# ['] 1+ fs-lelop ; -: fs-free#- ( -- ) fs_freecluster# ['] 1- fs-lelop ; -: fs-#free+ ( -- ) fs_#freeclusters ['] 1+ fs-lelop ; -: fs-#free- ( -- ) fs_#freeclusters ['] 1- fs-lelop ; +: fs-#free+ ( -- ) fs_#freeclusters dup lel@ 1+ swap lel! true fsinfos-dirty c! ; +: fs-#free- ( -- ) fs_#freeclusters dup lel@ 1- swap lel! true fsinfos-dirty c! ; +: fs-free#! ( cluster# -- ) fs_freecluster# lel! true fsinfos-dirty c! ;
- \ LICENSE_BEGIN \ Copyright (c) 2006 FirmWorks \
Modified: ofw/fs/fatfs/fat.fth =================================================================== --- ofw/fs/fatfs/fat.fth 2007-07-30 21:08:57 UTC (rev 506) +++ ofw/fs/fatfs/fat.fth 2007-08-01 03:11:46 UTC (rev 507) @@ -179,23 +179,20 @@ max-cl# l@ 1+ fatc-end @ search-up if mark-cluster exit then false ; -: allocate-cluster ( hint-cluster# -- cluster# true | false ) - fsinfo @ 0<> if - fs_#freeclusters lel@ 0= if - drop false - else - fs_freecluster# lel@ max-cl# l@ > if - (allocate-cluster) - dup if fs-#free- then - else - drop fs_freecluster# lel@ mark-cluster - fs-free#+ - fs-#free- - then - then - else - (allocate-cluster) - then +: allocate-cluster ( hint-cluster# -- false | cluster# true ) + fsinfo @ if ( hint ) + fs_#freeclusters lel@ if ( hint ) + fs_freecluster# lel@ max-cl# l@ <= if ( hint ) + drop fs_freecluster# lel@ ( hint' ) + then ( hint ) + (allocate-cluster) ( false | cluster# true ) + dup if over fs-free#! fs-#free- then ( false | cluster# true ) + else ( hint ) + drop false ( false ) + then ( false | cluster# true ) + else ( hint ) + (allocate-cluster) ( false | cluster# true ) + then ( false | cluster# true ) ;
\ Frees first-cl# and all clusters linked after it. @@ -205,7 +202,7 @@ while ( cluster# ) dup cluster@ ( cluster# next-cluster# ) 0 rot cluster! ( next-cluster# ) - fs-#free+ + fsinfo @ if fs-#free+ then ( next-cluster# ) repeat drop ?flush-fat-cache