.* .* $Header: D:/ext2-os2/doc/RCS/FEATURES.IM,v 1.2 1995/08/17 09:44:31 Willm Exp Willm $ .* .* Linux ext2 file system driver for OS/2 2.x and WARP - Allows OS/2 to .* access your Linux ext2fs partitions as normal drive letters. .* OS/2 implementation : Copyright (C) 1995 Matthieu WILLM .* .* This program is free software; you can redistribute it and/or modify .* it under the terms of the GNU General Public License as published by .* the Free Software Foundation; either version 2 of the License, or .* (at your option) any later version. .* .* This program is distributed in the hope that it will be useful, .* but WITHOUT ANY WARRANTY; without even the implied warranty of .* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the .* GNU General Public License for more details. .* .* You should have received a copy of the GNU General Public License .* along with this program; if not, write to the Free Software .* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. .******************************************************************************* .*** VI - Features, limitations and known bugs for this beta release. *** .******************************************************************************* .nameit symbol=titre_600 text='Features, limitations and known bugs for this release.' .nameit symbol=titre_601 text='Features and limitations' .nameit symbol=titre_602 text='Known bugs' :h1 id=600.&titre_600. :ol compact. :li.:link reftype=hd refid=601.&titre_601.:elink. :li.:link reftype=hd refid=602.&titre_602.:elink. :eol. :h2 id=601.&titre_601. :ul compact. :li.I only tested it on Warp, but it should work on OS/2 2.x and above. It will *NOT* work on OS/2 1.x. :li.I used the Linux 1.2.1 kernel sources, corresponding to ext2fs 0.5b and I tested my IFS only on this level of Linux/&EXT2FS. :li.User configurable per volume disk cache from (63 Kb to 60 * 63 Kb). :li.Global I-node cache, identical to Linux one. :li.Global directory entry cache, identical to Linux one. :li.Uses almost only original Linux ext2fs routines. :li.Works well only for a block size of 1 KB (it should work with other block sizes, but it has been minimally tested) :li.Doesn't support fragments (neither do the original Linux &EXT2FS. 0.5b code) :li.Linux special files (fifo, symbolic links, sockets, block and character devices) are mapped as SYSTEM files : you can see them with DIR /A but you normally can't read them :li.OS/2 mounts &EXT2FS. partitions as root. :li.Unlike Linux, file names beginning with '.' are not hidden :li.Hard links are properly handled :li.Symbolic links are not followed (treated as SYSTEM regular files) :li.Each ext2 partition has its own drive letter (provided you made them visible from OS/2) :li.It still completely ignores sharing modes (eg DosOpen with OPEN_SHARE_DENYxxx set). :li.Some OS/2 API are not yet or partially supported, for instance &colon. :ol compact. :li.DosResetBuffer : nothing done. :li.DosSetFSInfo : nothing done. :li.DosSetFileInfo : currently does nothing (EAS for instance are not written to disk ; standard attributes are not yet mapped and committed to disk...I plan to write a chmod utility to change standard Unix arrtibutes). :li.DosSetPathInfo : same thing as DosSetFileInfo :li.DosSetVerify : completely ignored on ext2fs partitions ! :eol. :li.&EXT2FS. specific behaviour of some &OS2. API &colon. :ol compact. :li.DosQueryFSInfo with FSIL_ALLOC (level 1) information returns the free space minus the reserved space. This should be consistent with Minix style df output (no fs overhead taken into account). :li.DosQueryFSInfo with FSIL_VOLSER (level 2) information returns EXT2FS_<drive> as volume label and a 32 bits CRC checksum of sector 0 as volume serial number. :eol. :li.Read an Write throughput is low, this is because synchronous writes are used (this was much simpler to implement), and ext2fs was designed with async I/Os in mind. I plan to implement asynchronous I/O once ext2-os2 is stabilized ; the solution is to call the device driver extended strategy entry point, instead of FSH_DOVOLIO which calls the standard strategy entry point. :eul. :h2 id=602.&titre_602. :p. There are still too many of them. This list is not complete but I'll try to keep it as much complete as possible, if you give me your feedback... :ul compact. :li.The mount process will mount the &EXT2FS. partition even if it has not been unmounted cleanly &colon. I STRONLY SUGGEST YOU TO UNMOUNT YOUR FILE SYSTEMS CLEANLY FROM LINUX - RUNNING THIS DRIVER ON A CORRUPTED EXT2FS PARTITION IS LIKELY TO CRASH YOU SYSTEM. :li.Removable media support has been only minimally tested. You *MUST* run sync.exe *BEFORE* removing a ext2fs formatted drive :li.DosFindNext() called from a 32 bits app (aka DosFindFromName) doesn't restart from the specified name, but from the last directory entry found. :li.Error recovery is limited - but it should be better than in 0.1a :li.I suggest you to avoid heavy concurrent access : a system halt or hang may occur if the same file is heavily accessed by several threads or processesat the same time. :li.A System halt may occur during heavy load (due to improperly testing when resources are exhausting) :li.Reported dates and times are sometimes dummy :li.As ext2fs doesn't support EAS, there are many cosmetic bugs with the workplace shell (some icons stay hatched....) :li.Some Windows apps, especially the Windows file manager, crash randomly. :li.Error codes returned from the IFS to OS/2 are sometimes not translated from Linux to OS/2. This will result in messages like "Cannot find message 56347" nstead of "Directory not empty" for instance. :li.Any app that either uppercase or lowercase file names are broken. I plan to fix it by providing a option to make ext2-os2 behave like HPFS (case retensive). :eul.