1 .. SPDX-License-Identifier: GPL-2.0
2
3 ====================
4 Read/Write HPFS 2.09
5 ====================
6
7 1998-2004, Mikulas Patocka
8
9 :email: mikulas@artax.karlin.mff.cuni.cz
10 :homepage: https://artax.karlin.mff.cuni.cz/~m
11
12 Credits
13 =======
14 Chris Smith, 1993, original read-only HPFS, so
15 is taken from it
16
17 Jacques Gelinas, MSDos mmap, Inspired by fs/nf
18
19 Werner Almesberger, 1992, 1993, MSDos option p
20
21 Mount options
22
23 uid=xxx,gid=xxx,umask=xxx (default uid=gid=0 u
24 Set owner/group/mode for files that do
25 attributes. Mode is inverted umask - f
26 all permission, group read permission
27 that for files mode is anded with 0666
28 rights, you must use extended attribut
29 case=lower,asis (default asis)
30 File name lowercasing in readdir.
31 conv=binary,text,auto (default binary)
32 CR/LF -> LF conversion, if auto, decis
33 - there is a list of text extensions (
34 text file than to damage binary file).
35 change it in the source. Original read
36 heuristic algorithm that I removed. I
37 computer decide whether file is text o
38 binaries contain small text message at
39 misidentified and damaged under some c
40 check=none,normal,strict (default normal)
41 Check level. Selecting none will cause
42 danger. I tried to write it so that it
43 corrupted filesystems. check=strict me
44 used for debugging (for example it che
45 bitmaps when accessing it).
46 errors=continue,remount-ro,panic (default remo
47 Behaviour when filesystem errors found
48 chkdsk=no,errors,always (default errors)
49 When to mark filesystem dirty so that
50 eas=no,ro,rw (default rw)
51 What to do with extended attributes. '
52 values specified in uid/gid/mode optio
53 attributes but do not create them. 'rw
54 when you use chmod/chown/chgrp/mknod/l
55 timeshift=(-)nnn (default 0)
56 Shifts the time by nnn seconds. For ex
57 one hour more, than under os/2, use ti
58
59
60 File names
61 ==========
62
63 As in OS/2, filenames are case insensitive. Ho
64 are case sensitive, so for example when you cr
65 'cat FOO', 'cat Foo', 'cat foo' or 'cat F*' bu
66 also won't be able to compile linux kernel (an
67 because kernel creates different files with na
68 bootsect.s. When searching for file thats name
69 are used - see below.
70 OS/2 ignores dots and spaces at the end of fil
71 well. If you create 'a. ...', the file 'a' wil
72 access it under names 'a.', 'a..', 'a . . . '
73
74
75 Extended attributes
76 ===================
77
78 On HPFS partitions, OS/2 can associate to each
79 extended attributes. Extended attributes are p
80 an ascii string identifying that attribute and
81 variable length. OS/2 stores window and icon p
82 why not use it for unix-specific info like fil
83 driver can do it. If you chown/chgrp/chmod on
84 attributes with keys "UID", "GID" or "MODE" an
85 that extended attributes those value differs f
86 options are created. Once created, the extende
87 they're just changed. It means that when your
88 something like 'chown luser file; chown root f
89 extended attribute UID=0. And when you umount
90 uid=luser_uid, the file will be still owned by
91 extended attribute "MODE" will not be set, thi
92 read-only flag. When you mknod a block or char
93 special 4-byte extended attribute "DEV" will b
94 number. Currently this driver cannot resize ex
95 that if somebody (I don't know who?) has set "
96 attributes with different sizes, they won't be
97 values doesn't work.
98
99
100 Symlinks
101 ========
102
103 You can do symlinks on HPFS partition, symlink
104 attribute named "SYMLINK" with symlink value.
105 chgrp symlinks but I don't know what is it goo
106 in chmoding file where symlink points. These s
107 incompatible with OS/2. OS/2 PmShell symlinks
108 stored in very crazy way. They tried to do it
109 moved ... sometimes it works. But the link is
110 extended attributes and partly in OS2SYS.INI.
111 to analyze or change OS2SYS.INI.
112
113
114 Codepages
115 =========
116
117 HPFS can contain several uppercasing tables fo
118 file has a pointer to codepage its name is in.
119 America where people don't care much about cod
120 support is quite buggy. I have Czech OS/2 work
121 Once I booted English OS/2 working in cp 850 a
122 partition. It marked file name codepage as 850
123 Czech OS/2, the file was completely inaccessib
124 OS/2 uppercases the search pattern with its sy
125 name it's comparing to with its code page (850
126 really what IBM developers wanted? But problem
127 Czech OS/2 another file in that directory, tha
128 probably uses different uppercasing method whe
129 (note, that files in HPFS directory must be so
130 a file. Finally when I opened this directory i
131 funny thing was that, when rebooted, PmShell t
132 again :-). chkdsk happily ignores these errors
133 modification saved me. Never mix different la
134 system although HPFS was designed to allow tha
135 OK, I could implement complex codepage support
136 would cause more problems than benefit with su
137 So this driver simply uses first codepage it f
138 lowercasing no matter what's file codepage ind
139 this codepage - if you don't try to do what I
140
141
142 Known bugs
143 ==========
144
145 HPFS386 on OS/2 server is not supported. HPFS3
146 should work. If you have OS/2 server, use only
147 to handle some HPFS386 structures like access
148 list, I don't know how to delete them when fil
149 overwrite them with extended attributes. Send
150 and I'll make it. However, this driver should
151 structures, remount read-only and not destroy
152
153 When there's not enough space for extended att
154 and no error is returned.
155
156 OS/2 can't access files if the path is longer
157 driver allows you to do it. chkdsk ignores suc
158
159 Sometimes you won't be able to delete some fil
160 (returning error ENOSPC). That's because file
161 (one directory, if it's large, has dirents in
162 with another node when deleted. And that new f
163 the old one so the new name doesn't fit in dir
164 would result in directory tree splitting, that
165 to delete other files that are leaf (probabili
166 about 1/50) or to truncate file first to make
167 You encounter this problem only if you have ma
168 preallocated directory band is full i.e.::
169
170 number_of_directories / size_of_filesy
171
172 You can't delete open directories.
173
174 You can't rename over directories (what is it
175
176 Renaming files so that only case changes doesn
177 but vfs doesn't. Something like 'mv file FILE'
178
179 All atimes and directory mtimes are not update
180 reasons. If you extremely wish to update them,
181 it will be slow).
182
183 When the system is out of memory and swap, it
184 (lost files, unbalanced directories). (I guess
185
186 When compiled, you get warning: function decla
187 anybody know what does it mean?
188
189
190 What does "unbalanced tree" message mean?
191 =========================================
192
193 Old versions of this driver created sometimes
194 chkdsk doesn't scream if the tree is unbalance
195 unbalanced trees too :-) but both HPFS and HPF
196 crashes when the tree is not balanced. This dr
197 correctly and writes warning if it finds them.
198 probably because of directories created with o
199 Workaround is to move all files from that dire
200 again. Do it in Linux, not OS/2! If you see th
201 whole created by this driver, it is BUG - let
202
203
204 Bugs in OS/2
205 ============
206
207 When you have two (or more) lost directories p
208 locks up when repairing filesystem.
209
210 Sometimes (I think it's random) when you creat
211 OS/2, OS/2 marks it as 'long'. chkdsk then rem
212 error corrected".
213
214 File names like "a .b" are marked as 'long' by
215 marks them as short (and writes "minor fs erro
216 HPFS386.
217
218 Codepage bugs described above
219 =============================
220
221 If you don't install fixpacks, there are many,
222
223
224 History
225 =======
226
227 ====== =======================================
228 0.90 First public release
229 0.91 Fixed bug that caused shooting to memor
230 open inode (rarely happened)
231 0.92 Fixed a little memory leak in freeing d
232 0.93 Fixed bug that locked up the machine wh
233 with first 15 characters same
234 Fixed write_file to zero file when writ
235 0.94 Fixed a little memory leak when trying
236 0.95 Fixed a bug that i_hpfs_parent_dir was
237 1.90 First version for 2.1.1xx kernels
238 1.91 Fixed a bug that chk_sectors failed whe
239 Fixed a race-condition when write_inode
240 Fixed a bug that could possibly happen
241 using 0xff in filenames.
242
243 Rewritten locking to avoid race-conditi
244
245 Mount option 'eas' now works
246
247 Fsync no longer returns error
248
249 Files beginning with '.' are marked hid
250
251 Remount support added
252
253 Alloc is not so slow when filesystem be
254
255 Atimes are no more updated because it s
256
257 Code cleanup (removed all commented deb
258 1.92 Corrected a bug when sync was called ju
259 1.93 Modified, so that it works with kernels
260 works with previous versions
261
262 Fixed a possible problem with disks > 6
263 test it)
264
265 Fixed a file overflow at 2G
266
267 Added new option 'timeshift'
268
269 Changed behaviour on HPFS386: It is now
270 read-only mode
271
272 Fixed a bug that slowed down alloc and
273 (this bug was not destructive)
274 1.94 Added workaround for one bug in Linux
275
276 Fixed one buffer leak
277
278 Fixed some incompatibilities with large
279 not 100% ok, I have no info on it and O
280
281 Rewritten allocation
282
283 Fixed a bug with i_blocks (du sometimes
284
285 Directories have no longer archive attr
286 it)
287
288 Fixed a bug that it set badly one flag
289 destructive)
290 1.95 Fixed one buffer leak, that could happe
291
292 Fixed one bug in allocation in 1.94
293 1.96 Added workaround for one bug in OS/2 (H
294 error sometimes when opening directorie
295
296 Fixed a possible bitmap race
297
298 Fixed possible problem on large disks
299
300 You can now delete open files
301
302 Fixed a nondestructive race in rename
303 1.97 Support for HPFS v3 (on large partition
304
305 ZFixed a bug that it didn't allow creat
306 (it should be 2G)
307 1.97.1 Changed names of global symbols
308
309 Fixed a bug when chmoding or chowning r
310 1.98 Fixed a deadlock when using old_readdir
311 Better directory handling; workaround f
312 1.99 Corrected a possible problem when there
313 file
314
315 Now it tries to truncate the file if th
316 deleting
317
318 Removed a lot of redundant code
319 2.00 Fixed a bug in rename (it was there sin
320 Better anti-fragmentation strategy
321 2.01 Fixed problem with directory listing ov
322
323 Directory lseek now checks for proper p
324
325 Fixed race-condition in buffer code - i
326 when reading device (cat /dev/hda) whil
327 could be damaged
328 2.02 Workaround for bug in breada in Linux.
329 end of partition
330 2.03 Char, block devices and pipes are corre
331
332 Fixed non-crashing race in unlink (Alex
333
334 Now it works with Japanese version of O
335 2.04 Fixed error when ftruncate used to exte
336 2.05 Fixed crash when got mount parameters w
337
338 Fixed crash when allocation of anode fa
339
340 Fixed some crashes when block io or ino
341 2.06 Fixed some crash on corrupted disk stru
342
343 Better allocation strategy
344
345 Reschedule points added so that it does
346
347 It should work in read-only mode on War
348 2.07 More fixes for Warp Server. Now it real
349 2.08 Creating new files is not so slow on la
350
351 An attempt to sync deleted file does no
352 2.09 Fixed error on extremely fragmented fil
353 ====== =======================================
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