2.6 must-fix list, v3

2.6 must-fix list, v3

[Andrew Morton]

Quite a lot of changes here.  Mostly additions, but some things have been
crossed off.

Also at ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/must-fix

--- notes/must-fix-1.txt	12 May 2003 22:53:08 -0000	1.10
+++ notes/must-fix-1.txt	14 May 2003 02:33:30 -0000	1.17
@@ -11,7 +11,21 @@
 
   - Other problems: aviro, dipankar, Alan have details.
 
+  - somebody will have to document the tty driver and ldisc API
 
+drivers/char/rtc/
+-----------------
+
+- rmk: I think we need a generic RTC driver (which is backed by real RTCs).
+   Integrator-based stuff has a 32-bit 1Hz counter RTC with alarm, as has the
+  SA11xx, and probably PXA.  There's another implementation for the RiscPC
+  and ARM26 stuff.  I'd rather not see 4 implementations of the RTC userspace
+  API, but one common implementation so that stuff gets done in a consistent
+  way.
+
+  We postponed this at the beginning of 2.4 until 2.5 happened.  We're now
+  at 2.5, and I'm about to add at least one more (the Integrator
+  implementation.) This isn't sane imo.
 
 drivers/block/
 --------------
@@ -58,7 +72,62 @@
   seems to be some cases that don't work too well.  Don't really have a
   handle on those :/
 
-- IDE tcq. Either kill it or fix it. Not a "big todo", as such.
+drivers/input/
+--------------
+
+- rmk: unconverted keyboard/mouse drivers (there's a deadline of 2.6.0
+  currently on these remaining in my/Linus' tree.)
+
+- synaptic touchpad support
+
+drivers/misc/
+-------------
+
+- rmk: UCB1[23]00 drivers, currently sitting in drivers/misc in the ARM
+  tree.  (touchscreen, audio, gpio, type device.)
+
+drivers/net/
+------------
+
+- rmk: network drivers.  ARM people like to add tonnes of #ifdefs into
+  these to customise them to their hardware platform (eg, chip access
+  methods, addresses, etc.) I cope with this by not integrating them into my
+  tree.  The result is that many ARM platforms can't be built from even my
+  tree without extra patches.  This isn't sane, and has bred a culture of
+  network drivers not being submitted.  I don't see this changing for 2.6
+  though.
+
+drivers/net/irda/
+-----------------
+
+- dongle drivers need to be converted to sir-dev
+
+- irport need to be converted to sir-kthread
+
+- new drivers (irtty-sir/smsc-ircc2/donauboe) need more testing
+
+- rmk: Refuse IrDA initialisation if sizeof(structures) is incorrect (I'm
+  not sure if we still need this; I think gcc 2.95.3 on ARM shows this
+  problem though.)
+
+drivers/pci/
+------------
+
+- alan: Some cardbus crashes the system
+
+- alan: Hotplug locking is hosed
+
+drivers/pcmcia/
+---------------
+
+- alan: Most drivers crash the system on eject randomly with timer bugs.  I
+  think after RMK's stuff is in most of the pcmcia/cardbus ones go except the
+  locking disaster.
+
+drivers/pld/
+------------
+
+- rmk: EPXA (ARM platform) PLD hotswap drivers (drivers/pld)
 
 drivers/video/
 --------------
@@ -70,6 +139,8 @@
 
 - hch: large parts of the locking are hosed or not existant
 
+  (Mike Anderson, Patrick Mansfield, Badari Pulavarty)
+
   - shost->my_devices isn't locked down at all
 
   - the host list ist locked but not refcounted, mess can happen when the
@@ -84,32 +155,38 @@
 
   - there's some global variables incremented without any locks
 
+- Convert am53c974, dpt_i2o, initio and pci2220i to DMA-mapping
 
-  (Mike Anderson, Patrick Mansfield, Badari Pulavarty)
+- Make inia100, cpqfc, pci2000 and dc390t compile
 
-  - large parts of the locking are hosed or non existent
+- Convert
 
-    -- shost->my_devices isn't locked at all
+   wd33c99 based: a2091 a3000 gpv11 mvme174 sgiwd93 53c7xx based:
+   amiga7xxx bvme6000 mvme16x initio am53c974 pci2000 pci2220i qla1280
+   sym53c8xx dc390t
 
-    -- host list locked but not refcounted
+  To new error handling
 
-    -- lots of members of struct scsi_host/scsi_device/ scsi_cmd with
-       very unclear locking
+  I think the sym53c8xx could probably be pulled out of the tree because
+  the sym_2 replaces it.  I'm also looking at converting the qla1280.
 
-    -- lots of volatile abuse in scsi code
+  It also might be possible to shift the 53c7xx based drivers over to
+  53c700 which does the new EH stuff, but I don't have the hardware to check
+  such a shift.
 
-    -- global variables incremented without locks.
+  For the non-compiling stuff, I've probably missed a few that just aren't
+  compilable on my platforms, so any updates would be welcome.  Also, are
+  some of our non-compiling or unconverted drivers obsolete?
 
-fs/
----
-
-- NFS client gets an OOM deadlock.
+drivers/usb/gadget/
+-------------------
 
-  - Some fixes exist in -mm.  Seem to mostly work.
+- rmk: SA11xx USB client/gadget code (David B has been doing some work on
+  this, and keeps trying to prod me, but unfortunately I haven't had the time
+  to look at his work, sorry David.)
 
-- NFS client runs very slowly consuming 100% CPU under heavy writeout.
-
-  - Unsubtle fix exists in -mm.  (Looks like it's fixed anyway).
+fs/
+---
 
 - ext3 data=journal mode is bust.
 
@@ -119,13 +196,6 @@
 
   - Easy fix is to only allow the feature for S_ISBLK files.
 
-- davej: NFS seems to have a really bad time for some people.  (Including
-  myself on one testbox).  The common factor seems to be a high spec client
-  torturing an underpowered NFS server with lots of IO.  (fsx/fsstress etc
-  show this up).  Lots of "NFS server cheating" messages get dumped, and a
-  whole lot of bogus packets start appearing.  They look severely corrupted,
-  (they even crashed ethereal once 8-)
-
 - hch: devfs: there's a fundamental lookup vs devfsd race that's only
   fixable by introducing a lookup vs devfs deadlock.  I can't see how this is
   fixable without getting rid of the current devfsd design.  Mandrake seems
@@ -147,7 +217,9 @@
 
 - Alan: 32bit uid support is *still* broken for process accounting.
 
-  (Test case?)
+  Create a 32bit uid, turn accounting on.  Shock horror it doesn't work
+  because the field is 16bit.  We need an acct structure flag day for 2.6
+  IMHO
 
 mm/
 ---
@@ -175,8 +247,13 @@
 
 - Per-cpu support inside modules (have patch, in testing).
 
-- driver class code is getting redone.  I have this now working, and will
-  send it out in a few days.
+- shemminger: The module remove rework that Rusty and Dave are working on
+  needs to be fixed before 2.6.  Right now, it is impossible to write a
+  protocol or network device that can be safely unloaded when it is a module.
+
+  See:
+        http://pizda.ninka.net/~davem/modules.html
+
 
 net/
 ----
@@ -219,7 +296,6 @@
   Someone has to get a good log in order for us to effectively debug this.
 
 
-
 net/*/netfilter/
 ----------------
 
@@ -231,6 +307,19 @@
 
 - Module relationship bogosity fix (trivial, have patch).
 
+sound/
+------
+
+- rmk: several OSS drivers for SA11xx-based hardware in need of
+  ALSA-ification and L3 bus support code for these.
+
+- rmk: linux/sound/drivers/mpu401/mpu401.c and
+  linux/sound/drivers/virmidi.c complained about 'errno' at some time in the
+  past, need to confirm whether this is still a problem.
+
+- rmk: need to complete ALSA-ification of the WaveArtist driver for both
+  NetWinder and other stuff (there's some fairly fundamental differences in
+  the way the mixer needs to be handled for the NetWinder.)
 
 global
 ------
@@ -255,8 +344,6 @@
 - Framework for selecting IO schedulers.  This is the main one really. 
   Once this is in place we can drop in new schedulers any old time, no risk.
 
-- Dynamic disk request allocation.  Patch exists.
-
 - Runtime-selectable disk scheduler framework.
 
 - Anticipatory scheduler.  Working OK now, still has problems with seeky
@@ -309,6 +396,10 @@
    path_walk()/open_namei().  I'm still working on the latter (Peter has
    already completed the lookup with intent stuff).
 
+- rmk: update acorn partition parsing code - making all acorn schemes
+  appear in check.c so we don't have to duplicate the scanning of multiple
+  types, and adding support for eesox partitions.
+
 
 kernel/
 -------
@@ -329,6 +420,16 @@
 
 - kexec.  Seems to work, is in -mm.
 
+- rmk: modules / /proc/kcore / vmalloc This needs sorting and testing to
+  ensure that stuff like gdb vmlinux /proc/kcore works as expected.  I
+  believe this is the only show stopper preventing any ARM platform being
+  built in Linus' kernel.
+
+- rmk: lib/inflate.c must not use static variables (causes these to be
+  referenced via GOTOFF relocations in PIC decompressor.  We have a PIC
+  decompressor to avoid having to hard code a per platform zImage link
+  address into the makefiles.)
+
 mm/
 ---
 
@@ -372,14 +473,6 @@
   This is low priority, because technically it creates suboptimal behavior
   rather than mis-operation.
 
-- IPV4 output engine changes for IPSEC need to be moved over to IPV6.
-
-  IPV6 ipsec works but gravely suboptimally in some cases.  It is also for
-  this reason that the zerocopy UDP stuff isn't functional on the ipv6 side.
-
-  The USAGI project (www.linux-ipv6.org) is working with Alexey on this
-  work.
-
 net/*/netfilter/
 ----------------
 
@@ -474,15 +567,12 @@
 drivers
 =======
 
-- Alan: PCI random reordering from 2.4 to 2.5 isnt understood yet (might be
-  fixed now?)
-
 - Alan: We have multiple drivers walking the pci device lists and also
   using things like pci_find_device in unsafe ways with no refcounting.  I
   think we have to make pci_find_device etc refcount somewhere and add
   pci_device_put as was done with networking.
 
-- Lots of network drivers don't even build
+- Some network drivers don't even build
 
 - Alan: PCI hotplug is unsafe (locking is totally screwed)
 
@@ -499,17 +589,16 @@
   "network card doesn't recieve packets" booting with 'acpi=off noapic' fixes
   it.
 
+  alan: VIA APIC stuff is one bit of this, there are also some other
+  reports that were caused by ACPI not setting level v edge trigger some
+  times
+
 - davej: There's also another nasty 'doesnt boot' bug which quite a few
   people (myself included) are seeing on some boxes (especially laptops).
 
 drivers/block/
 --------------
 
-- Alan: Partition handling is hosed for DM users.  (I have some partly
-  debugged patches in the -ac tree, but Andries objects to them and I think
-  his user knows magic options hack is unacceptable too.  Mostly this is
-  figuring out the right answer)
-
 - Floppy is almost unusably buggy still
 
 drivers/char/
@@ -519,6 +608,8 @@
   thankfully).  "The badness I know about is almost entirely IRQ mishandling.
    DRI failing to mask PCI irqs on exit paths."
 
+  (might be fixed due to DRI updates?)
+
 - Various suspect things in AGP.
 
 drivers/ide/
@@ -528,18 +619,25 @@
 
 - IDE requires bio walking
 
+  "Bartlomiej has IDE multisector working" (does that mean it's fixed?)
+
+
 - IDE PIO has occasional unexplained PIO disk eating reports
 
 - IDE has multiple zillions of races/hangs in 2.5 still
 
-- IDE eats disks with HPT372N on 2.5.x
-
 - IDE scsi needs rewriting
 
 - IDE needs significant reworking to handle Simplex right
 
 - IDE hotplug handling for 2.5 is completely broken still
 
+- IDE tcq. Either kill it or fix it. Not a "big todo", as such.
+
+- There are lots of other IDE bugs that wont go away until the taskfile
+  stuff is included, the locking bugs that allow any user to hang the IDE
+  layer in 2.5, and some other updates are forward ported.  (esp.  HPT372N).
+
 drivers/isdn/
 -------------
 
@@ -561,9 +659,6 @@
   Alternatively, we could re-introduce the fallback to driver ioctl parsing
   for these if not enough drivers get updated.
 
-- fixup the usb-serial core and drivers to provide support for this
-  patch.
-
 drivers/net/
 ------------
 
@@ -583,12 +678,24 @@
 
 - 2.5.x won't boot on some 440GX
 
-- 2.5.x doesn't handle VIA APIC right yet - dont know why
+  alan: Problem understood now, feasible fix in 2.4/2.4-ac.  (440GX has two
+  IRQ routers, we use the $PIR table with the PIIX, but the 440GX doesnt use
+  the PIIX for its IRQ routing).  Fall back to BIOS for 440GX works and Intel
+  concurs.
+
+- 2.5.x doesn't handle VIA APIC right yet.
+
+  1. We must write the PCI_INTERRUPT_LINE
+
+  2. We have quirk handlers that seem to trash it.
 
 - ACPI needs the relax patches merging to work on lots of laptops
 
 - ECC driver questions are not yet sorted (DaveJ is working on this)
 
+- PC9800 is not fully merged - most of this I think is 2.7 stuff but a few
+  bits might be 2.6 candidate
+
 arch/x86_64/
 ------------
 
@@ -596,19 +703,37 @@
 
 - time handling is broken. Need to move up 2.4 time.c code.
 
-- memory corruption with IOMMU pci_free_consistent - often causes crashes
-  at shutdown.  This is rather mysterious, the code is basically identical to
-  2.4 which works fine.  Can only be seen on systems with >4GB of memory or
-  with iommu=force
-
 - Another report of a crash at shutdown on Simics with no iommu when all
   memory was used.  Could be related to the one above.
 
-- change_page_attr corrupts memory/crashes. Breaks some AGP users.
-
 - NMI watchdog seems to tick too fast
 
 - some fixes from 2.4 still need to be merged
 
 - not very well tested. probably more bugs lurking.
+
+- 32bit vsyscalls seem to be broken
+
+- 32bit elf coredumps are broken
+
+- need to coredump 64bit vsyscall code with dwarf2
+
+- move 64bit signal trampolines into vsyscall code and add dwarf2 for it.
+
+- describe kernel assembly with dwarf2 annotations for kgdb (currently
+  waiting on some binutils changes for this) 
+
+arch/arm/
+---------
+
+- rmk: missing raw keyboard translation tables for all ARM machines. 
+  Haven't even looked into this at all.  This could be messy since there
+  isn't an ARM architecture standard.  I'm presently hoping that it won't be
+  an issue.  If it does, I guess we'll see drivers/char/keyboard.c explode.
+
+arch/others/
+------------
+
+- SH3/SH3-64 need resyncing, as do some other ports.  No impact on
+  mainstream platforms hopefully.
 

Re: 2.6 must-fix list, v3

[Andrew Morton]

The full list:


Must-fix bugs
=============

drivers/char/
-------------

- TTY locking is broken.

  - see FIXME in do_tty_hangup().  This causes ppp BUGs in local_bh_enable()

  - Other problems: aviro, dipankar, Alan have details.

  - somebody will have to document the tty driver and ldisc API

drivers/char/rtc/
-----------------

- rmk: I think we need a generic RTC driver (which is backed by real RTCs).
   Integrator-based stuff has a 32-bit 1Hz counter RTC with alarm, as has the
  SA11xx, and probably PXA.  There's another implementation for the RiscPC
  and ARM26 stuff.  I'd rather not see 4 implementations of the RTC userspace
  API, but one common implementation so that stuff gets done in a consistent
  way.

  We postponed this at the beginning of 2.4 until 2.5 happened.  We're now
  at 2.5, and I'm about to add at least one more (the Integrator
  implementation.) This isn't sane imo.

drivers/block/
--------------

- RAID0 dies on strangely aligned BIOs

  - Need to hoist BIO-split code out of device mapper, use that.

 (neilb)

 1/ RAID5 should work fine.  It accepts any sort of bio and always
    submits a 1-page bio to the underlying device, and if my
    understanding is correct, every device must be able to handle a
    single page bio, no matter what the alignment (which is why raid0
    has a problem - it doesn't). 

 2/ RAID1 works pretty well.  The only improvement needed is to define
    a merge_bvec_fn function which passes the question down to lower
    layers.  This should be easy except for the small fact that it is
    impossible :-)  There is no enforced pairing between calls to
    merge_bvec_fn and submit_bh, so it is possible that a hot spare
    with different restrictions could get swapped in between the one
    and the other and could confuse things.  I suspect that can be
    worked around somehow though...

       Someone sent me a patch that is sorely needed - it allows you
       to simply call blk_queue_stack() (or somethink like that), and it will
       get your stacked limits set appropriately.

 3/ I just realised that raid0 is easier than I had previously
    thought.  We don't need the completely functional bio splitting
    that dm has.  We only need to be able to split a bio that has just
    one page as the use of merge_bvec_fn will ensure that we never get
    a larger bio that we cannot handle.  And splitting a bio with only
    one page is a lot easier.  I now have code in my tree that
    implements this quite cleanly and will probably post a patch
    during the week.

- ideraid hasn't been ported to 2.5 at all yet.

- CD burning.  There are still a few quirks to solve wrt SG_IO and ide-cd.

  Jens: The basic hang has been solved (double fault in ide-cd), there still
  seems to be some cases that don't work too well.  Don't really have a
  handle on those :/

drivers/input/
--------------

- rmk: unconverted keyboard/mouse drivers (there's a deadline of 2.6.0
  currently on these remaining in my/Linus' tree.)

- synaptic touchpad support

drivers/misc/
-------------

- rmk: UCB1[23]00 drivers, currently sitting in drivers/misc in the ARM
  tree.  (touchscreen, audio, gpio, type device.)

drivers/net/
------------

- rmk: network drivers.  ARM people like to add tonnes of #ifdefs into
  these to customise them to their hardware platform (eg, chip access
  methods, addresses, etc.) I cope with this by not integrating them into my
  tree.  The result is that many ARM platforms can't be built from even my
  tree without extra patches.  This isn't sane, and has bred a culture of
  network drivers not being submitted.  I don't see this changing for 2.6
  though.

drivers/net/irda/
-----------------

- dongle drivers need to be converted to sir-dev

- irport need to be converted to sir-kthread

- new drivers (irtty-sir/smsc-ircc2/donauboe) need more testing

- rmk: Refuse IrDA initialisation if sizeof(structures) is incorrect (I'm
  not sure if we still need this; I think gcc 2.95.3 on ARM shows this
  problem though.)

drivers/pci/
------------

- alan: Some cardbus crashes the system

- alan: Hotplug locking is hosed

drivers/pcmcia/
---------------

- alan: Most drivers crash the system on eject randomly with timer bugs.  I
  think after RMK's stuff is in most of the pcmcia/cardbus ones go except the
  locking disaster.

drivers/pld/
------------

- rmk: EPXA (ARM platform) PLD hotswap drivers (drivers/pld)

drivers/video/
--------------

- Lots of drivers don't compile, others do but don't work.

drivers/scsi/
-------------

- hch: large parts of the locking are hosed or not existant

  (Mike Anderson, Patrick Mansfield, Badari Pulavarty)

  - shost->my_devices isn't locked down at all

  - the host list ist locked but not refcounted, mess can happen when the
    spinlock is dropped

  - there are lots of members of struct Scsi_Host/scsi_device/scsi_cmnd
    with very unclear locking, many of them probably want to become
    atomic_t's or bitmaps (for the 1bit bitfields).

  - there's lots of volatile abuse in the scsi code that needs to be
    thought about.

  - there's some global variables incremented without any locks

- Convert am53c974, dpt_i2o, initio and pci2220i to DMA-mapping

- Make inia100, cpqfc, pci2000 and dc390t compile

- Convert

   wd33c99 based: a2091 a3000 gpv11 mvme174 sgiwd93 53c7xx based:
   amiga7xxx bvme6000 mvme16x initio am53c974 pci2000 pci2220i qla1280
   sym53c8xx dc390t

  To new error handling

  I think the sym53c8xx could probably be pulled out of the tree because
  the sym_2 replaces it.  I'm also looking at converting the qla1280.

  It also might be possible to shift the 53c7xx based drivers over to
  53c700 which does the new EH stuff, but I don't have the hardware to check
  such a shift.

  For the non-compiling stuff, I've probably missed a few that just aren't
  compilable on my platforms, so any updates would be welcome.  Also, are
  some of our non-compiling or unconverted drivers obsolete?

drivers/usb/gadget/
-------------------

- rmk: SA11xx USB client/gadget code (David B has been doing some work on
  this, and keeps trying to prod me, but unfortunately I haven't had the time
  to look at his work, sorry David.)

fs/
---

- ext3 data=journal mode is bust.

- ext3/htree doesn't play right with NFS server.  90% fixed in -mm.

- AIO/direct-IO writes can race with truncate and wreck filesystems.

  - Easy fix is to only allow the feature for S_ISBLK files.

- hch: devfs: there's a fundamental lookup vs devfsd race that's only
  fixable by introducing a lookup vs devfs deadlock.  I can't see how this is
  fixable without getting rid of the current devfsd design.  Mandrake seems
  to have a workaround for this so this is at least not triggered so easily,
  but that's not what I'd consider a fix..

kernel/
-------

- O(1) scheduler starvation, poor behaviour seems unresolved.

  Jens: "I've been running 2.5.67-mm3 on my workstation for two days, and
  it still doesn't feel as good as 2.4.  It's not a disaster like some
  revisisons ago, but it still has occasional CPU "stalls" where it feels
  like a process waits for half a second of so for CPU time.  That's is very
  noticable."

   Also see Mike Galbraith's work.

- Alan: 32bit uid support is *still* broken for process accounting.

  Create a 32bit uid, turn accounting on.  Shock horror it doesn't work
  because the field is 16bit.  We need an acct structure flag day for 2.6
  IMHO

mm/
---

- Overcommit accounting gets wrong answers

  - underestimates reclaimable slab, gives bogus failures when
    dcache&icache are large.

  - gets confused by reclaimable-but-not-freed truncated ext3 pages. 
    Lame fix exists in -mm.

- Proper user level no overcommit also requires a root margin adding

modules
-------

  (Rusty)

- The .modinfo patch needs to go in.  It's trivial, but it's the major
  missing functionality vs. 2.4.  Keeps bouncing off Linus.

- __module_get(): "I know I have a refcount already and I don't care
  if they're doing rmmod --wait, gimme.".  Keeps bouncing off Linus.

- Per-cpu support inside modules (have patch, in testing).

- shemminger: The module remove rework that Rusty and Dave are working on
  needs to be fixed before 2.6.  Right now, it is impossible to write a
  protocol or network device that can be safely unloaded when it is a module.

  See:
        http://pizda.ninka.net/~davem/modules.html


net/
----

  (davem)

- UDP apps can in theory deadlock, because the ip_append_data path can end
  up sleeping while the socket lock is held.

  It is OK to sleep with the socket held held, normally.  But in this case
  the sleep happens while waiting for socket memory/space to become
  available, if another context needs to take the socket lock to free up the
  space we could hang.

  I sent a rough patch on how to fix this to Alexey, and he is analyzing
  the situation.  I expect a final fix from him next week or so.

- Semantics for IPSEC during operations such as TCP connect suck currently.

  When we first try to connect to a destination, we may need to ask the
  IPSEC key management daemon to resolve the IPSEC routes for us.  For the
  purposes of what the kernel needs to do, you can think of it like ARP.  We
  can't send the packet out properly until we resolve the path.

  What happens now for IPSEC is basically this:

  O_NONBLOCK: returns -EAGAIN over and over until route is resolved

  !O_NONBLOCK: Sleeps until route is resolved

  These semantics are total crap.  The solution, which Alexey is working
  on, is to allow incomplete routes to exist.  These "incomplete" routes
  merely put the packet onto a "resolution queue", and once the key manager
  does it's thing we finish the output of the packet.  This is precisely how
  ARP works.

  I don't know when Alexey will be done with this.

- There are those mysterious TCP hangs of established state sockets. 
  Someone has to get a good log in order for us to effectively debug this.


net/*/netfilter/
----------------

  (Rusty)

- Handle non-linear skbs everywhere.  This is going in via Dave now.

- Rework conntrack hashing.

- Module relationship bogosity fix (trivial, have patch).

sound/
------

- rmk: several OSS drivers for SA11xx-based hardware in need of
  ALSA-ification and L3 bus support code for these.

- rmk: linux/sound/drivers/mpu401/mpu401.c and
  linux/sound/drivers/virmidi.c complained about 'errno' at some time in the
  past, need to confirm whether this is still a problem.

- rmk: need to complete ALSA-ification of the WaveArtist driver for both
  NetWinder and other stuff (there's some fairly fundamental differences in
  the way the mixer needs to be handled for the NetWinder.)

global
------

- Lots of 2.4 fixes including some security are not in 2.5

- There are about 60 or 70 security related checks that need doing
  (copy_user etc) from Stanford tools

- A couple of hundred real looking bugzilla bugs




Not-ready features and speedups
===============================


drivers/block/
--------------

- Framework for selecting IO schedulers.  This is the main one really. 
  Once this is in place we can drop in new schedulers any old time, no risk.

- Runtime-selectable disk scheduler framework.

- Anticipatory scheduler.  Working OK now, still has problems with seeky
  OLTP-style loads.

- CFQ scheduler.  Seems to work but Jens planning significant rework.

- The feral.com qlogic driver: needs work.


fs/
---

- reiserfs_file_write() speedup.  There are concerns that some applications
  do the wrong thing with large stat.st_blksize.

- ext3 lock_kernel() removal: that part works OK and is mergeable.  But
  we'll also need to make lock_journal() a spinlock, and that's deep surgery.

- 32bit quota needs a lot more testing but may work now

- Integrate Chris Mason's 2.4 reiserfs ordered data and data journaling
  patches.  They make reiserfs a lot safer.

- (Trond:) Yes: I'm still working on an atomic "open()", i.e.  one
           where we short-circuit the usual VFS path_walk() + lookup() +
           permission() + create() + ....  bullsh*t...

           I have several reasons for wanting to do this (all of
           them related to NFS of course, but much of the reasoning applies
           to *all* networked file systems).

   1) The above sequence is simply not atomic on *any* networked
      filesystem.

   2) It introduces a sh*tload of completely unnecessary RPC calls (why
      do a 'permission' RPC call when the server is in *any* case going to
      tell you whether or not this operations is allowed.  Why do a
      'lookup()' when the 'create()' call can be made to tell you whether or
      not a file already exists).

   3) It is incompatible with some operations: the current create()
      doesn't pass an 'EXCLUSIVE' flag down to the filesystems.

   4) (NFS specific?) open() has very different cache consistency
      requirements when compared to most other VFS operations.

   I'd very much like for something like Peter Braam's 'lookup with
   intent' or (better yet) for a proper dentry->open() to be integrated with
   path_walk()/open_namei().  I'm still working on the latter (Peter has
   already completed the lookup with intent stuff).

- rmk: update acorn partition parsing code - making all acorn schemes
  appear in check.c so we don't have to duplicate the scanning of multiple
  types, and adding support for eesox partitions.


kernel/
-------

  (Rusty)

- Zippel's Reference count simplification.  Tricky code, but cuts about 120
  lines from module.c.  Patch exists, needs stressing.

- /proc/kallsyms.  What most people really wanted from /proc/ksyms.  Patch
  exists.

- Fix module-failed-init races by starting module "disabled".  Patch
  exists, requires some subsystems (ie.  add_partition) to explicitly say
  "make module live now".  Without patch we are no worse off than 2.4 etc. 

- Integrate userspace irq balancing daemon.

- kexec.  Seems to work, is in -mm.

- rmk: modules / /proc/kcore / vmalloc This needs sorting and testing to
  ensure that stuff like gdb vmlinux /proc/kcore works as expected.  I
  believe this is the only show stopper preventing any ARM platform being
  built in Linus' kernel.

- rmk: lib/inflate.c must not use static variables (causes these to be
  referenced via GOTOFF relocations in PIC decompressor.  We have a PIC
  decompressor to avoid having to hard code a per platform zImage link
  address into the makefiles.)

mm/
---

- objrmap: concerns over page reclaim performance at high sharing levels,
  and interoperation with nonlinear mappings is hairy.

- Readd and make /proc/sys/vm/freepages writable again so that boxes can be
  tuned for heavy interrupt load.

net/
----

  (davem)

- Real serious use of IPSEC is hampered by lack of MPLS support.  MPLS is a
  switching technology that works by switching based upon fixed length labels
  prepended to packets.  Many people use this and IPSEC to implement VPNs
  over public networks, it is also used for things like traffic engineering.

  A good reference site is:

	http://www.mplsrc.com/

  Anyways, an existing (crappy) implementation exists.  I've almost
  completed a rewrite, I should have something in the tree next week.

- Sometimes we generate IP fragments when it truly isn't necessary.

  The way IP fragmentation is specified, each fragment must be modulo 8
  bytes in length.  So suppose the device has an MTU that is not 0 modulo 8,
  ethernet even classifies in this way.  1500 == (8 * 187) + 4

  Our IP fragmenting engine can fragment on packets that are sized within
  the last modulo 8 bytes of the MTU.  This happens in obscure cases, but it
  does happen.

  I've proposed a fix to Alexey, whereby very late in the output path we
  check the packet, if we fragmented but the data length would fit into the
  MTU we unfragment the packet.

  This is low priority, because technically it creates suboptimal behavior
  rather than mis-operation.

net/*/netfilter/
----------------

- Lots of misc. cleanups, which are happening slowly.

- davem: Netfilter needs to stop linearizing packets as much as possible.

  Zerocopy output packets are basically undone by netfilter becuase all of
  it assumed it was working with linear socket buffers.

  Rusty is fixing this piece by piece.  He is nearly done with this work. 

power management
----------------

  (Pat) There is some preliminary work at bk://ldm.bkbits.net/linux-2.5-power,
  though I'm currently in the process of reworking it.  

  It includes: 

- New device power management core code, both for individual devices, 
  and for global state transitions. 

- A generic user interface for triggering system power state transitions.

- Arch-independent code for performing state transitions, that calls 
  platform-specific methods along the way. 

- A better suspend-to-disk mechanism than swsusp. 

  There are various other details to be worked out, which are the real fun
  part.  And of course, driver support, but that is something that can happen
  at any time.  

  (Alan)

- PCI locking

- Frame buffer restore codepaths (that requires some deep PCI magic)

- XFree86 hooks

- AGP restoration

- DRI restoration

- IDE suspend/resume without races (Ben is looking at this a little)

- How to deal with devices that babble (some stuff we have to global IRQ
  off to save, and global IRQ on -after- we recover with APM)

- Pat's swsusp rework?

- Pat: There are already CPU device structures; MTRRs should be a
  dynamically registered interface of CPUs, which implies there needs
  to be some other glue to know that there are MTRRs that need to be
  saved/restored.

arch/i386/
----------

- Andi: i386 sub architectures for common boxes (in particular bigsmp and
  summit) need to be runtime probed options, not compile time.  Vendors
  cannot ship an own kernel rpm for all these cases.  (patch is in -mm, works
  OK).

- Also PC9800 merge needs finishing to the point we want for 2.6 (not all).

- ES7000 wants merging (now we are all happy with it).  That shouldn't be a
  big problem.

global
------

- 64-bit dev_t.  Seems almost ready, but it's not really known how much
  work is still to do.  Patches exist in -mm but with the recent rise of the
  neo-viro I'm not sure where things are at.

- We need a kernel side API for reporting error events to userspace (could
  be async to 2.6 itself)

  (Prototype core based on netlink exists)

- Kai: Introduce a sane, easy and standard way to build external modules

- Kai: Allow separate src/objdir





drivers
=======

- Alan: We have multiple drivers walking the pci device lists and also
  using things like pci_find_device in unsafe ways with no refcounting.  I
  think we have to make pci_find_device etc refcount somewhere and add
  pci_device_put as was done with networking.

- Some network drivers don't even build

- Alan: PCI hotplug is unsafe (locking is totally screwed)

- Ditto cardbus

- Alan: Cardbus/PCMCIA requires all Russell's stuff is merged to do
  multiheader right and so on

drivers/acpi/
-------------

- davej: ACPI has a number of failures right now.  There are a number of
  entries in bugzilla which could all be the same bug.  It manifests as a
  "network card doesn't recieve packets" booting with 'acpi=off noapic' fixes
  it.

  alan: VIA APIC stuff is one bit of this, there are also some other
  reports that were caused by ACPI not setting level v edge trigger some
  times

- davej: There's also another nasty 'doesnt boot' bug which quite a few
  people (myself included) are seeing on some boxes (especially laptops).

drivers/block/
--------------

- Floppy is almost unusably buggy still

drivers/char/
-------------

- Alan: Multiple serious bugs in the DRI drivers (most now with patches
  thankfully).  "The badness I know about is almost entirely IRQ mishandling.
   DRI failing to mask PCI irqs on exit paths."

  (might be fixed due to DRI updates?)

- Various suspect things in AGP.

drivers/ide/
------------

  (Alan)

- IDE requires bio walking

  "Bartlomiej has IDE multisector working" (does that mean it's fixed?)


- IDE PIO has occasional unexplained PIO disk eating reports

- IDE has multiple zillions of races/hangs in 2.5 still

- IDE scsi needs rewriting

- IDE needs significant reworking to handle Simplex right

- IDE hotplug handling for 2.5 is completely broken still

- IDE tcq. Either kill it or fix it. Not a "big todo", as such.

- There are lots of other IDE bugs that wont go away until the taskfile
  stuff is included, the locking bugs that allow any user to hang the IDE
  layer in 2.5, and some other updates are forward ported.  (esp.  HPT372N).

drivers/isdn/
-------------

  (Kai, rmk)

- isdn_tty locking is completely broken (cli() and friends)

- fix lots of remaining bugs in the isdn link layer / hisax protocol layer
  / hisax subdrivers, so that at least 99% of the users have a usable ISDN
  subsystem

- fix other drivers

- lots more cleanups, adaption to recent APIs etc

- fixup tty-based ISDN drivers which provide TIOCM* ioctls (see my recent
  3-set patch for serial stuff)

  Alternatively, we could re-introduce the fallback to driver ioctl parsing
  for these if not enough drivers get updated.

drivers/net/
------------

- davej: Either Wireless network drivers or PCMCIA broke somewhen.  A
  configuration that worked fine under 2.4 doesn't receive any packets.  Need
  to look into this more to make sure I don't have any misconfiguration that
  just 'happened to work' under 2.4


drivers/scsi/
-------------

- Half of SCSI doesn't compile

arch/i386/
----------

- 2.5.x won't boot on some 440GX

  alan: Problem understood now, feasible fix in 2.4/2.4-ac.  (440GX has two
  IRQ routers, we use the $PIR table with the PIIX, but the 440GX doesnt use
  the PIIX for its IRQ routing).  Fall back to BIOS for 440GX works and Intel
  concurs.

- 2.5.x doesn't handle VIA APIC right yet.

  1. We must write the PCI_INTERRUPT_LINE

  2. We have quirk handlers that seem to trash it.

- ACPI needs the relax patches merging to work on lots of laptops

- ECC driver questions are not yet sorted (DaveJ is working on this)

- PC9800 is not fully merged - most of this I think is 2.7 stuff but a few
  bits might be 2.6 candidate

arch/x86_64/
------------

  (Andi)

- time handling is broken. Need to move up 2.4 time.c code.

- Another report of a crash at shutdown on Simics with no iommu when all
  memory was used.  Could be related to the one above.

- NMI watchdog seems to tick too fast

- some fixes from 2.4 still need to be merged

- not very well tested. probably more bugs lurking.

- 32bit vsyscalls seem to be broken

- 32bit elf coredumps are broken

- need to coredump 64bit vsyscall code with dwarf2

- move 64bit signal trampolines into vsyscall code and add dwarf2 for it.

- describe kernel assembly with dwarf2 annotations for kgdb (currently
  waiting on some binutils changes for this) 

arch/arm/
---------

- rmk: missing raw keyboard translation tables for all ARM machines. 
  Haven't even looked into this at all.  This could be messy since there
  isn't an ARM architecture standard.  I'm presently hoping that it won't be
  an issue.  If it does, I guess we'll see drivers/char/keyboard.c explode.

arch/others/
------------

- SH3/SH3-64 need resyncing, as do some other ports.  No impact on
  mainstream platforms hopefully.

Re: 2.6 must-fix list, v3

[Jens Axboe]

On Wed, May 14 2003, Andrew Morton wrote:
> 
> Quite a lot of changes here.  Mostly additions, but some things have been
> crossed off.
> 
> -- IDE tcq. Either kill it or fix it. Not a "big todo", as such.

ide tcq should be fixed now

-- 
Jens Axboe

Re: 2.6 must-fix list, v3

[Tom Rini]

On Wed, May 14, 2003 at 03:27:12AM -0700, Andrew Morton wrote:

> +drivers/char/rtc/
> +-----------------
> +
> +- rmk: I think we need a generic RTC driver (which is backed by real RTCs).
> +   Integrator-based stuff has a 32-bit 1Hz counter RTC with alarm, as has the
> +  SA11xx, and probably PXA.  There's another implementation for the RiscPC
> +  and ARM26 stuff.  I'd rather not see 4 implementations of the RTC userspace
> +  API, but one common implementation so that stuff gets done in a consistent
> +  way.
> +
> +  We postponed this at the beginning of 2.4 until 2.5 happened.  We're now
> +  at 2.5, and I'm about to add at least one more (the Integrator
> +  implementation.) This isn't sane imo.

I know Geert asked, but what's wrong with the current generic RTC
driver (drivers/char/genrtc.c), and why couldn't the additional features be
added to it, ala the battery bits that went in semi-recently?

-- 
Tom Rini
http://gate.crashing.org/~trini/

Re: 2.6 must-fix list, v3

[Greg KH]

On Wed, May 14, 2003 at 03:27:12AM -0700, Andrew Morton wrote:
> 
> Quite a lot of changes here.  Mostly additions, but some things have been
> crossed off.
> 
> Also at ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/must-fix

Here's a patch against must-fix-3.txt that consolodates the 4 different
places people are complaining about a lack of PCI device locking, and
put the bugzilla bug number for it.

As soon as I finish this OLS paper, I'm going to work on finally fixing
this...

thanks,

greg k-h

--- must-fix-3.txt.original	Wed May 14 09:46:43 2003
+++ must-fix-3.txt	Wed May 14 09:52:47 2003
@@ -115,7 +115,11 @@
 
 - alan: Some cardbus crashes the system
 
-- alan: Hotplug locking is hosed
+- We have multiple drivers walking the pci device lists and also using
+  things like pci_find_device in unsafe ways with no refcounting.  I think
+  we have to make pci_find_device etc refcount somewhere and add
+  pci_device_put as was done with networking.
+  http://bugzilla.kernel.org/show_bug.cgi?id=709
 
 drivers/pcmcia/
 ---------------
@@ -567,17 +571,8 @@
 drivers
 =======
 
-- Alan: We have multiple drivers walking the pci device lists and also
-  using things like pci_find_device in unsafe ways with no refcounting.  I
-  think we have to make pci_find_device etc refcount somewhere and add
-  pci_device_put as was done with networking.
-
 - Some network drivers don't even build
 
-- Alan: PCI hotplug is unsafe (locking is totally screwed)
-
-- Ditto cardbus
-
 - Alan: Cardbus/PCMCIA requires all Russell's stuff is merged to do
   multiheader right and so on
 

Re: 2.6 must-fix list, v3

[Matt Mackall]

On Wed, May 14, 2003 at 03:27:12AM -0700, Andrew Morton wrote:
> 
> Quite a lot of changes here.  Mostly additions, but some things have been
> crossed off.

Has handling of async write errors fallen off your radar? Should I
start pushing that again?

-- 
Matt Mackall : http://www.selenic.com : of or relating to the moon

Re: 2.6 must-fix list, v3

[Andrew Morton]

Matt Mackall <mpm@selenic.com> wrote:
>
> On Wed, May 14, 2003 at 03:27:12AM -0700, Andrew Morton wrote:
> > 
> > Quite a lot of changes here.  Mostly additions, but some things have been
> > crossed off.
> 
> Has handling of async write errors fallen off your radar? Should I
> start pushing that again?
> 

No, I haven't forgotten.  If you want to rediff the patches sometime that'd
be appreciated, thanks.

[PATCH] write errors [1/3] async-write-errors

[Matt Mackall]

On Wed, May 14, 2003 at 10:44:55AM -0700, Andrew Morton wrote:
> Matt Mackall <mpm@selenic.com> wrote:
> >
> > On Wed, May 14, 2003 at 03:27:12AM -0700, Andrew Morton wrote:
> > > 
> > > Quite a lot of changes here.  Mostly additions, but some things have been
> > > crossed off.
> > 
> > Has handling of async write errors fallen off your radar? Should I
> > start pushing that again?
> > 
> 
> No, I haven't forgotten.  If you want to rediff the patches sometime that'd
> be appreciated, thanks.

Ok, rediffed and tested against 2.5.70-mm2. 1 of 3.


Record async write errors and report at subsequent fsync/fdatasync.

diff -urN -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/buffer.c patched/fs/buffer.c
--- orig/fs/buffer.c	2003-05-21 11:03:25.000000000 -0500
+++ patched/fs/buffer.c	2003-05-21 12:44:43.000000000 -0500
@@ -180,15 +180,29 @@
  * Default synchronous end-of-IO handler..  Just mark it up-to-date and
  * unlock the buffer. This is what ll_rw_block uses too.
  */
-void end_buffer_io_sync(struct buffer_head *bh, int uptodate)
+void end_buffer_read_sync(struct buffer_head *bh, int uptodate)
 {
 	if (uptodate) {
 		set_buffer_uptodate(bh);
 	} else {
-		/*
-		 * This happens, due to failed READA attempts.
-		 * buffer_io_error(bh);
-		 */
+		/* This happens, due to failed READA attempts. */
+		clear_buffer_uptodate(bh);
+	}
+	unlock_buffer(bh);
+	put_bh(bh);
+}
+
+void end_buffer_write_sync(struct buffer_head *bh, int uptodate)
+{
+	char b[BDEVNAME_SIZE];
+
+	if (uptodate) {
+		set_buffer_uptodate(bh);
+	} else {
+		buffer_io_error(bh);
+		printk(KERN_WARNING "lost page write due to I/O error on %s\n",
+		       bdevname(bh->b_bdev, b));
+		set_buffer_write_io_error(bh);
 		clear_buffer_uptodate(bh);
 	}
 	unlock_buffer(bh);
@@ -556,6 +570,7 @@
  */
 void end_buffer_async_write(struct buffer_head *bh, int uptodate)
 {
+	char b[BDEVNAME_SIZE];
 	static spinlock_t page_uptodate_lock = SPIN_LOCK_UNLOCKED;
 	unsigned long flags;
 	struct buffer_head *tmp;
@@ -568,6 +583,9 @@
 		set_buffer_uptodate(bh);
 	} else {
 		buffer_io_error(bh);
+		printk(KERN_WARNING "lost page write due to I/O error on %s\n",
+		       bdevname(bh->b_bdev, b));
+		page->mapping->error = -EIO;
 		clear_buffer_uptodate(bh);
 		SetPageError(page);
 	}
@@ -1300,7 +1318,7 @@
 		if (buffer_dirty(bh))
 			buffer_error();
 		get_bh(bh);
-		bh->b_end_io = end_buffer_io_sync;
+		bh->b_end_io = end_buffer_read_sync;
 		submit_bh(READ, bh);
 		if (-EIOCBRETRY == wait_on_buffer_wq(bh, wait))
 			return ERR_PTR(-EIOCBRETRY);
@@ -2661,8 +2679,10 @@
 		buffer_error();
 	if (rw == READ && buffer_dirty(bh))
 		buffer_error();
-				
-	set_buffer_req(bh);
+
+	/* Only clear out a write error when rewriting */
+	if (test_set_buffer_req(bh) && rw == WRITE)
+		clear_buffer_write_io_error(bh);
 
 	/*
 	 * from here on down, it's all bio -- do the initial mapping,
@@ -2722,13 +2742,14 @@
 			continue;
 
 		get_bh(bh);
-		bh->b_end_io = end_buffer_io_sync;
 		if (rw == WRITE) {
+			bh->b_end_io = end_buffer_write_sync;
 			if (test_clear_buffer_dirty(bh)) {
 				submit_bh(WRITE, bh);
 				continue;
 			}
 		} else {
+			bh->b_end_io = end_buffer_read_sync;
 			if (!buffer_uptodate(bh)) {
 				submit_bh(rw, bh);
 				continue;
@@ -2749,7 +2770,7 @@
 	lock_buffer(bh);
 	if (test_clear_buffer_dirty(bh)) {
 		get_bh(bh);
-		bh->b_end_io = end_buffer_io_sync;
+		bh->b_end_io = end_buffer_write_sync;
 		submit_bh(WRITE, bh);
 		wait_on_buffer(bh);
 	} else {
@@ -2808,6 +2829,8 @@
 	bh = head;
 	do {
 		check_ttfb_buffer(page, bh);
+		if (buffer_write_io_error(bh))
+			page->mapping->error = -EIO;
 		if (buffer_busy(bh))
 			goto failed;
 		if (!buffer_uptodate(bh) && !buffer_req(bh))
diff -urN -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/inode.c patched/fs/inode.c
--- orig/fs/inode.c	2003-05-21 11:03:26.000000000 -0500
+++ patched/fs/inode.c	2003-05-21 12:37:26.000000000 -0500
@@ -144,6 +144,7 @@
 		mapping->dirtied_when = 0;
 		mapping->assoc_mapping = NULL;
 		mapping->backing_dev_info = &default_backing_dev_info;
+		mapping->error = 0;
 		if (sb->s_bdev)
 			mapping->backing_dev_info = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
 		memset(&inode->u, 0, sizeof(inode->u));
diff -urN -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/mpage.c patched/fs/mpage.c
--- orig/fs/mpage.c	2003-04-19 21:48:55.000000000 -0500
+++ patched/fs/mpage.c	2003-05-21 12:37:26.000000000 -0500
@@ -388,6 +388,7 @@
 mpage_writepage(struct bio *bio, struct page *page, get_block_t get_block,
 	sector_t *last_block_in_bio, int *ret, struct writeback_control *wbc)
 {
+	struct address_space *mapping = page->mapping;
 	struct inode *inode = page->mapping->host;
 	const unsigned blkbits = inode->i_blkbits;
 	unsigned long end_index;
@@ -562,6 +563,17 @@
 	if (bio)
 		bio = mpage_bio_submit(WRITE, bio);
 	*ret = page->mapping->a_ops->writepage(page, wbc);
+	if (*ret < 0) {
+		/*
+		 * lock the page to keep truncate away
+		 * then check that it is still on the
+		 * mapping.
+		 */
+		lock_page(page);
+		if (page->mapping == mapping)
+			mapping->error = *ret;
+		unlock_page(page);
+	}
 out:
 	return bio;
 }
@@ -665,6 +677,17 @@
 					test_clear_page_dirty(page)) {
 			if (writepage) {
 				ret = (*writepage)(page, wbc);
+				if (ret < 0) {
+					/*
+					 * lock the page to keep truncate away
+					 * then check that it is still on the
+					 * mapping.
+					 */
+					lock_page(page);
+					if (page->mapping == mapping)
+						mapping->error = ret;
+					unlock_page(page);
+				}
 			} else {
 				bio = mpage_writepage(bio, page, get_block,
 					&last_block_in_bio, &ret, wbc);
diff -urN -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/ntfs/compress.c patched/fs/ntfs/compress.c
--- orig/fs/ntfs/compress.c	2003-05-12 14:34:30.000000000 -0500
+++ patched/fs/ntfs/compress.c	2003-05-21 12:37:26.000000000 -0500
@@ -643,7 +643,7 @@
 			continue;
 		}
 		atomic_inc(&tbh->b_count);
-		tbh->b_end_io = end_buffer_io_sync;
+		tbh->b_end_io = end_buffer_read_sync;
 		submit_bh(READ, tbh);
 	}
 
diff -urN -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/open.c patched/fs/open.c
--- orig/fs/open.c	2003-05-21 11:03:26.000000000 -0500
+++ patched/fs/open.c	2003-05-21 12:37:26.000000000 -0500
@@ -842,21 +842,38 @@
  */
 int filp_close(struct file *filp, fl_owner_t id)
 {
-	int retval;
+	struct address_space *mapping = filp->f_dentry->d_inode->i_mapping;
+	int retval = 0, err;
+
+	/* Report and clear outstanding errors */
+	err = filp->f_error;
+	if (err) {
+		filp->f_error = 0;
+		retval = err;
+	}
+
+	err = mapping->error;
+	if (err && !retval) {
+		mapping->error = 0;
+		retval = err;
+	}
 
 	if (!file_count(filp)) {
 		printk(KERN_ERR "VFS: Close: file count is 0\n");
-		return 0;
+		return retval;
 	}
-	retval = 0;
+
 	if (filp->f_op && filp->f_op->flush) {
 		lock_kernel();
-		retval = filp->f_op->flush(filp);
+		err = filp->f_op->flush(filp);
 		unlock_kernel();
+		if (err && !retval)
+			retval = err;
 	}
 	dnotify_flush(filp, id);
 	locks_remove_posix(filp, id);
 	fput(filp);
+
 	return retval;
 }
 
diff -urN -x '*.ver' -x '.patch*' -x '*.orig' orig/include/linux/buffer_head.h patched/include/linux/buffer_head.h
--- orig/include/linux/buffer_head.h	2003-05-21 11:03:28.000000000 -0500
+++ patched/include/linux/buffer_head.h	2003-05-21 12:42:06.000000000 -0500
@@ -24,8 +24,9 @@
 	BH_Async_Read,	/* Is under end_buffer_async_read I/O */
 	BH_Async_Write,	/* Is under end_buffer_async_write I/O */
 	BH_Delay,	/* Buffer is not yet allocated on disk */
-
 	BH_Boundary,	/* Block is followed by a discontiguity */
+	BH_Write_EIO,	/* I/O error on write */
+
 	BH_PrivateStart,/* not a state bit, but the first bit available
 			 * for private allocation by other entities
 			 */
@@ -109,12 +110,14 @@
 BUFFER_FNS(Lock, locked)
 TAS_BUFFER_FNS(Lock, locked)
 BUFFER_FNS(Req, req)
+TAS_BUFFER_FNS(Req, req)
 BUFFER_FNS(Mapped, mapped)
 BUFFER_FNS(New, new)
 BUFFER_FNS(Async_Read, async_read)
 BUFFER_FNS(Async_Write, async_write)
-BUFFER_FNS(Delay, delay);
+BUFFER_FNS(Delay, delay)
 BUFFER_FNS(Boundary, boundary)
+BUFFER_FNS(Write_EIO,write_io_error)
 
 #define bh_offset(bh)		((unsigned long)(bh)->b_data & ~PAGE_MASK)
 #define touch_buffer(bh)	mark_page_accessed(bh->b_page)
@@ -139,7 +142,8 @@
 int try_to_free_buffers(struct page *);
 void create_empty_buffers(struct page *, unsigned long,
 			unsigned long b_state);
-void end_buffer_io_sync(struct buffer_head *bh, int uptodate);
+void end_buffer_read_sync(struct buffer_head *bh, int uptodate);
+void end_buffer_write_sync(struct buffer_head *bh, int uptodate);
 void end_buffer_async_write(struct buffer_head *bh, int uptodate);
 
 /* Things to do with buffers at mapping->private_list */
diff -urN -x '*.ver' -x '.patch*' -x '*.orig' orig/include/linux/fs.h patched/include/linux/fs.h
--- orig/include/linux/fs.h	2003-05-21 11:03:29.000000000 -0500
+++ patched/include/linux/fs.h	2003-05-21 12:37:27.000000000 -0500
@@ -329,6 +329,7 @@
 	spinlock_t		private_lock;	/* for use by the address_space */
 	struct list_head	private_list;	/* ditto */
 	struct address_space	*assoc_mapping;	/* ditto */
+	int			error;		/* write error for fsync */
 };
 
 struct block_device {
diff -urN -x '*.ver' -x '.patch*' -x '*.orig' orig/kernel/ksyms.c patched/kernel/ksyms.c
--- orig/kernel/ksyms.c	2003-05-21 11:03:33.000000000 -0500
+++ patched/kernel/ksyms.c	2003-05-21 12:42:26.000000000 -0500
@@ -175,7 +175,8 @@
 EXPORT_SYMBOL(d_lookup);
 EXPORT_SYMBOL(d_path);
 EXPORT_SYMBOL(mark_buffer_dirty);
-EXPORT_SYMBOL(end_buffer_io_sync);
+EXPORT_SYMBOL(end_buffer_read_sync);
+EXPORT_SYMBOL(end_buffer_write_sync);
 EXPORT_SYMBOL(end_buffer_async_write);
 EXPORT_SYMBOL(__mark_inode_dirty);
 EXPORT_SYMBOL(get_empty_filp);
diff -urN -x '*.ver' -x '.patch*' -x '*.orig' orig/mm/filemap.c patched/mm/filemap.c
--- orig/mm/filemap.c	2003-05-21 11:03:33.000000000 -0500
+++ patched/mm/filemap.c	2003-05-21 12:41:34.000000000 -0500
@@ -199,6 +199,14 @@
 		spin_lock(&mapping->page_lock);
 	}
 	spin_unlock(&mapping->page_lock);
+
+	/* Check for outstanding write errors */
+	if (mapping->error)
+	{
+		ret = mapping->error;
+		mapping->error = 0;
+	}
+
 	return ret;
 }
 
diff -urN -x '*.ver' -x '.patch*' -x '*.orig' orig/mm/vmscan.c patched/mm/vmscan.c
--- orig/mm/vmscan.c	2003-05-21 11:03:33.000000000 -0500
+++ patched/mm/vmscan.c	2003-05-21 12:37:27.000000000 -0500
@@ -340,6 +340,20 @@
 				SetPageReclaim(page);
 				res = mapping->a_ops->writepage(page, &wbc);
 
+				if (res < 0) {
+					/*
+					 * lock the page to keep truncate away
+					 * then check that it is still on the
+					 * mapping.
+					 */
+					lock_page(page);
+					if (page->mapping == mapping)
+						mapping->error = res;
+					unlock_page(page);
+				}
+				if (res < 0) {
+					mapping->error = res;
+				}
 				if (res == WRITEPAGE_ACTIVATE) {
 					ClearPageReclaim(page);
 					goto activate_locked;


-- 
Matt Mackall : http://www.selenic.com : of or relating to the moon

[PATCH] write errors [2/3] flags

[Matt Mackall]

Combine mapping->error and ->gfp_mask into ->flags

diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/drivers/block/loop.c patched/drivers/block/loop.c
--- orig/drivers/block/loop.c	2003-05-29 12:49:24.000000000 -0500
+++ patched/drivers/block/loop.c	2003-05-29 12:52:28.000000000 -0500
@@ -714,8 +714,8 @@
 		fput(file);
 		goto out_putf;
 	}
-	lo->old_gfp_mask = inode->i_mapping->gfp_mask;
-	inode->i_mapping->gfp_mask = GFP_NOIO;
+	lo->old_gfp_mask = mapping_gfp_mask(inode->i_mapping);
+	mapping_set_gfp_mask(inode->i_mapping, GFP_NOIO);
 
 	set_blocksize(bdev, lo_blocksize);
 
@@ -823,7 +823,7 @@
 	memset(lo->lo_name, 0, LO_NAME_SIZE);
 	invalidate_bdev(bdev, 0);
 	set_capacity(disks[lo->lo_number], 0);
-	filp->f_dentry->d_inode->i_mapping->gfp_mask = gfp;
+	mapping_set_gfp_mask(filp->f_dentry->d_inode->i_mapping, gfp);
 	lo->lo_state = Lo_unbound;
 	fput(filp);
 	/* This is safe: open() is still holding a reference. */
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/block_dev.c patched/fs/block_dev.c
--- orig/fs/block_dev.c	2003-05-29 12:49:42.000000000 -0500
+++ patched/fs/block_dev.c	2003-05-29 12:52:28.000000000 -0500
@@ -318,7 +318,7 @@
 			inode->i_rdev = kdev;
 			inode->i_bdev = new_bdev;
 			inode->i_data.a_ops = &def_blk_aops;
-			inode->i_data.gfp_mask = GFP_USER;
+			mapping_set_gfp_mask(&inode->i_data, GFP_USER);
 			inode->i_data.backing_dev_info = &default_backing_dev_info;
 			spin_lock(&bdev_lock);
 			bdev = bdfind(dev, head);
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/buffer.c patched/fs/buffer.c
--- orig/fs/buffer.c	2003-05-29 12:52:33.000000000 -0500
+++ patched/fs/buffer.c	2003-05-29 12:52:28.000000000 -0500
@@ -600,7 +600,7 @@
 		buffer_io_error(bh);
 		printk(KERN_WARNING "lost page write due to I/O error on %s\n",
 		       bdevname(bh->b_bdev, b));
-		page->mapping->error = -EIO;
+		set_bit(AS_EIO, &page->mapping->flags);
 		clear_buffer_uptodate(bh);
 		SetPageError(page);
 	}
@@ -2846,7 +2846,7 @@
 	do {
 		check_ttfb_buffer(page, bh);
 		if (buffer_write_io_error(bh))
-			page->mapping->error = -EIO;
+			set_bit(AS_EIO, &page->mapping->flags);
 		if (buffer_busy(bh))
 			goto failed;
 		if (!buffer_uptodate(bh) && !buffer_req(bh))
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/inode.c patched/fs/inode.c
--- orig/fs/inode.c	2003-05-29 12:52:33.000000000 -0500
+++ patched/fs/inode.c	2003-05-29 12:53:07.000000000 -0500
@@ -18,6 +18,7 @@
 #include <linux/hash.h>
 #include <linux/swap.h>
 #include <linux/security.h>
+#include <linux/pagemap.h>
 #include <linux/cdev.h>
 
 /*
@@ -142,11 +143,11 @@
 
 		mapping->a_ops = &empty_aops;
  		mapping->host = inode;
-		mapping->gfp_mask = GFP_HIGHUSER;
+		mapping->flags = 0;
+		mapping_set_gfp_mask(mapping, GFP_HIGHUSER);
 		mapping->dirtied_when = 0;
 		mapping->assoc_mapping = NULL;
 		mapping->backing_dev_info = &default_backing_dev_info;
-		mapping->error = 0;
 		if (sb->s_bdev)
 			mapping->backing_dev_info = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
 		memset(&inode->u, 0, sizeof(inode->u));
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/jfs/inode.c patched/fs/jfs/inode.c
--- orig/fs/jfs/inode.c	2003-04-19 21:48:46.000000000 -0500
+++ patched/fs/jfs/inode.c	2003-05-29 12:52:28.000000000 -0500
@@ -20,6 +20,7 @@
 #include <linux/fs.h>
 #include <linux/mpage.h>
 #include <linux/buffer_head.h>
+#include <linux/pagemap.h>
 #include "jfs_incore.h"
 #include "jfs_filsys.h"
 #include "jfs_imap.h"
@@ -57,7 +58,7 @@
 		inode->i_op = &jfs_dir_inode_operations;
 		inode->i_fop = &jfs_dir_operations;
 		inode->i_mapping->a_ops = &jfs_aops;
-		inode->i_mapping->gfp_mask = GFP_NOFS;
+		mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
 	} else if (S_ISLNK(inode->i_mode)) {
 		if (inode->i_size >= IDATASIZE) {
 			inode->i_op = &page_symlink_inode_operations;
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/jfs/jfs_imap.c patched/fs/jfs/jfs_imap.c
--- orig/fs/jfs/jfs_imap.c	2003-04-19 21:48:53.000000000 -0500
+++ patched/fs/jfs/jfs_imap.c	2003-05-29 12:52:28.000000000 -0500
@@ -43,6 +43,7 @@
 
 #include <linux/fs.h>
 #include <linux/buffer_head.h>
+#include <linux/pagemap.h>
 
 #include "jfs_incore.h"
 #include "jfs_filsys.h"
@@ -504,7 +505,7 @@
 	}
 
 	ip->i_mapping->a_ops = &jfs_aops;
-	ip->i_mapping->gfp_mask = GFP_NOFS;
+	mapping_set_gfp_mask(ip->i_mapping, GFP_NOFS);
 
 	if ((inum == FILESYSTEM_I) && (JFS_IP(ip)->ipimap == sbi->ipaimap)) {
 		sbi->gengen = le32_to_cpu(dp->di_gengen);
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/jfs/namei.c patched/fs/jfs/namei.c
--- orig/fs/jfs/namei.c	2003-04-19 21:50:35.000000000 -0500
+++ patched/fs/jfs/namei.c	2003-05-29 12:52:28.000000000 -0500
@@ -257,7 +257,7 @@
 	ip->i_op = &jfs_dir_inode_operations;
 	ip->i_fop = &jfs_dir_operations;
 	ip->i_mapping->a_ops = &jfs_aops;
-	ip->i_mapping->gfp_mask = GFP_NOFS;
+	mapping_set_gfp_mask(ip->i_mapping, GFP_NOFS);
 
 	insert_inode_hash(ip);
 	mark_inode_dirty(ip);
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/mpage.c patched/fs/mpage.c
--- orig/fs/mpage.c	2003-05-29 12:52:33.000000000 -0500
+++ patched/fs/mpage.c	2003-05-29 12:52:28.000000000 -0500
@@ -570,8 +570,12 @@
 		 * mapping.
 		 */
 		lock_page(page);
-		if (page->mapping == mapping)
-			mapping->error = *ret;
+		if (page->mapping == mapping) {
+			if (*ret == -EIO)
+				set_bit(AS_EIO, &mapping->flags);
+			else if (*ret == -ENOSPC)
+				set_bit(AS_ENOSPC, &mapping->flags);
+		}
 		unlock_page(page);
 	}
 out:
@@ -684,8 +688,12 @@
 					 * mapping.
 					 */
 					lock_page(page);
-					if (page->mapping == mapping)
-						mapping->error = ret;
+					if (page->mapping == mapping) {
+						if (ret == -EIO)
+							set_bit(AS_EIO, &mapping->flags);
+						else if (ret == -ENOSPC)
+							set_bit(AS_ENOSPC, &mapping->flags);
+					}
 					unlock_page(page);
 				}
 			} else {
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/open.c patched/fs/open.c
--- orig/fs/open.c	2003-05-29 12:52:33.000000000 -0500
+++ patched/fs/open.c	2003-05-29 12:52:28.000000000 -0500
@@ -20,6 +20,7 @@
 #include <linux/mount.h>
 #include <linux/vfs.h>
 #include <asm/uaccess.h>
+#include <linux/pagemap.h>
 
 #define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))
 
@@ -852,11 +853,10 @@
 		retval = err;
 	}
 
-	err = mapping->error;
-	if (err && !retval) {
-		mapping->error = 0;
-		retval = err;
-	}
+	if (test_and_clear_bit(AS_ENOSPC, &mapping->flags))
+		retval = -ENOSPC;
+	if (test_and_clear_bit(AS_EIO, &mapping->flags))
+		retval = -EIO;
 
 	if (!file_count(filp)) {
 		printk(KERN_ERR "VFS: Close: file count is 0\n");
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/include/linux/fs.h patched/include/linux/fs.h
--- orig/include/linux/fs.h	2003-05-29 12:52:33.000000000 -0500
+++ patched/include/linux/fs.h	2003-05-29 12:52:28.000000000 -0500
@@ -324,12 +324,11 @@
 	struct list_head	i_mmap_shared;	/* list of shared mappings */
 	struct semaphore	i_shared_sem;	/* protect both above lists */
 	unsigned long		dirtied_when;	/* jiffies of first page dirtying */
-	int			gfp_mask;	/* how to allocate the pages */
+	unsigned long		flags;		/* error bits/gfp mask */
 	struct backing_dev_info *backing_dev_info; /* device readahead, etc */
 	spinlock_t		private_lock;	/* for use by the address_space */
 	struct list_head	private_list;	/* ditto */
 	struct address_space	*assoc_mapping;	/* ditto */
-	int			error;		/* write error for fsync */
 };
 
 struct block_device {
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/include/linux/gfp.h patched/include/linux/gfp.h
--- orig/include/linux/gfp.h	2003-05-12 14:34:35.000000000 -0500
+++ patched/include/linux/gfp.h	2003-05-29 12:52:28.000000000 -0500
@@ -33,6 +33,9 @@
 #define __GFP_NORETRY	0x1000	/* Do not retry.  Might fail */
 #define __GFP_NO_GROW	0x2000	/* Slab internal usage */
 
+#define __GFP_BITS_SHIFT 16	/* Room for 16 __GFP_FOO bits */
+#define __GFP_BITS_MASK ((1 << __GFP_BITS_SHIFT) - 1)
+
 #define GFP_ATOMIC	(__GFP_HIGH)
 #define GFP_NOIO	(__GFP_WAIT)
 #define GFP_NOFS	(__GFP_WAIT | __GFP_IO)
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/include/linux/pagemap.h patched/include/linux/pagemap.h
--- orig/include/linux/pagemap.h	2003-05-29 12:52:33.000000000 -0500
+++ patched/include/linux/pagemap.h	2003-05-29 12:52:28.000000000 -0500
@@ -8,7 +8,30 @@
 #include <linux/fs.h>
 #include <linux/list.h>
 #include <linux/highmem.h>
+#include <linux/pagemap.h>
 #include <asm/uaccess.h>
+#include <linux/gfp.h>
+
+/*
+ * Bits in mapping->flags.  The lower __GFP_BITS_SHIFT bits are the page
+ * allocation mode flags.
+ */
+#define	AS_EIO		(__GFP_BITS_SHIFT + 0)	/* IO error on async write */
+#define AS_ENOSPC	(__GFP_BITS_SHIFT + 1)	/* ENOSPC on async write */
+
+static inline int mapping_gfp_mask(struct address_space * mapping)
+{
+	return mapping->flags & __GFP_BITS_MASK;
+}
+
+/*
+ * This is non-atomic.  Only to be used before the mapping is activated.
+ * Probably needs a barrier...
+ */
+static inline void mapping_set_gfp_mask(struct address_space *m, int mask)
+{
+	m->flags = (m->flags & ~__GFP_BITS_MASK) | mask;
+}
 
 /*
  * The page cache can done in larger chunks than
@@ -29,12 +52,12 @@
 
 static inline struct page *page_cache_alloc(struct address_space *x)
 {
-	return alloc_pages(x->gfp_mask, 0);
+	return alloc_pages(mapping_gfp_mask(x), 0);
 }
 
 static inline struct page *page_cache_alloc_cold(struct address_space *x)
 {
-	return alloc_pages(x->gfp_mask|__GFP_COLD, 0);
+	return alloc_pages(mapping_gfp_mask(x)|__GFP_COLD, 0);
 }
 
 typedef int filler_t(void *, struct page *);
@@ -56,7 +79,7 @@
  */
 static inline struct page *grab_cache_page(struct address_space *mapping, unsigned long index)
 {
-	return find_or_create_page(mapping, index, mapping->gfp_mask);
+	return find_or_create_page(mapping, index, mapping_gfp_mask(mapping));
 }
 
 extern struct page * grab_cache_page_nowait(struct address_space *mapping,
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/mm/filemap.c patched/mm/filemap.c
--- orig/mm/filemap.c	2003-05-29 12:52:33.000000000 -0500
+++ patched/mm/filemap.c	2003-05-29 12:52:28.000000000 -0500
@@ -201,11 +201,10 @@
 	spin_unlock(&mapping->page_lock);
 
 	/* Check for outstanding write errors */
-	if (mapping->error)
-	{
-		ret = mapping->error;
-		mapping->error = 0;
-	}
+	if (test_and_clear_bit(AS_ENOSPC, &mapping->flags))
+		ret = -ENOSPC;
+	if (test_and_clear_bit(AS_EIO, &mapping->flags))
+		ret = -EIO;
 
 	return ret;
 }
@@ -591,7 +590,7 @@
 		page_cache_release(page);
 		return NULL;
 	}
-	gfp_mask = mapping->gfp_mask & ~__GFP_FS;
+	gfp_mask = mapping_gfp_mask(mapping) & ~__GFP_FS;
 	page = alloc_pages(gfp_mask, 0);
 	if (page && add_to_page_cache_lru(page, mapping, index, gfp_mask)) {
 		page_cache_release(page);
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/mm/shmem.c patched/mm/shmem.c
--- orig/mm/shmem.c	2003-05-29 12:49:55.000000000 -0500
+++ patched/mm/shmem.c	2003-05-29 12:52:28.000000000 -0500
@@ -318,7 +318,7 @@
 		spin_unlock(&sbinfo->stat_lock);
 
 		spin_unlock(&info->lock);
-		page = shmem_dir_alloc(inode->i_mapping->gfp_mask);
+		page = shmem_dir_alloc(mapping_gfp_mask(inode->i_mapping));
 		if (page) {
 			clear_highpage(page);
 			page->nr_swapped = 0;
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/mm/vmscan.c patched/mm/vmscan.c
--- orig/mm/vmscan.c	2003-05-29 12:52:34.000000000 -0500
+++ patched/mm/vmscan.c	2003-05-29 12:52:28.000000000 -0500
@@ -347,13 +347,14 @@
 					 * mapping.
 					 */
 					lock_page(page);
-					if (page->mapping == mapping)
-						mapping->error = res;
+					if (page->mapping == mapping) {
+						if (res == -EIO)
+							set_bit(AS_EIO, &mapping->flags);
+						else if (res == -ENOSPC)
+							set_bit(AS_ENOSPC, &mapping->flags);
+					}
 					unlock_page(page);
 				}
-				if (res < 0) {
-					mapping->error = res;
-				}
 				if (res == WRITEPAGE_ACTIVATE) {
 					ClearPageReclaim(page);
 					goto activate_locked;


-- 
Matt Mackall : http://www.selenic.com : of or relating to the moon

[PATCH] write errors [3/3] fs-writepage-truncate

[Matt Mackall]

Get rid of newly exposed (and meaningless) EIO errors from truncate
races in filesystems

diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/buffer.c patched/fs/buffer.c
--- orig/fs/buffer.c	2003-05-21 13:26:41.000000000 -0500
+++ patched/fs/buffer.c	2003-05-21 13:26:41.000000000 -0500
@@ -2625,7 +2625,7 @@
 		 */
 		block_invalidatepage(page, 0);
 		unlock_page(page);
-		return -EIO;
+		return 0; /* don't care */
 	}
 
 	/*
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/cifs/file.c patched/fs/cifs/file.c
--- orig/fs/cifs/file.c	2003-05-12 14:34:30.000000000 -0500
+++ patched/fs/cifs/file.c	2003-05-21 13:26:41.000000000 -0500
@@ -433,12 +433,18 @@
 	write_data = kmap(page);
 	write_data += from;
 
-	if((to > PAGE_CACHE_SIZE) || (from > to) || (offset > mapping->host->i_size)) {
+	if((to > PAGE_CACHE_SIZE) || (from > to)) {
 		kunmap(page);
 		FreeXid(xid);
 		return -EIO;
 	}
 
+	/* racing with truncate? */
+	if(offset > mapping->host->i_size) {
+		FreeXid(xid);
+		return 0; /* don't care */
+	}
+
 	/* check to make sure that we are not extending the file */
 	if(mapping->host->i_size - offset < (loff_t)to)
 		to = (unsigned)(mapping->host->i_size - offset); 
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/nfs/write.c patched/fs/nfs/write.c
--- orig/fs/nfs/write.c	2003-05-21 12:54:32.000000000 -0500
+++ patched/fs/nfs/write.c	2003-05-21 13:30:39.000000000 -0500
@@ -241,7 +241,7 @@
 	offset = inode->i_size & (PAGE_CACHE_SIZE-1);
 
 	/* OK, are we completely out? */
-	err = -EIO;
+	err = 0; /* potential race with truncate - ignore */
 	if (page->index >= end_index+1 || !offset)
 		goto out;
 do_it:
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/ntfs/aops.c patched/fs/ntfs/aops.c
--- orig/fs/ntfs/aops.c	2003-05-12 14:34:30.000000000 -0500
+++ patched/fs/ntfs/aops.c	2003-05-21 13:26:41.000000000 -0500
@@ -811,8 +811,8 @@
 	if (unlikely(page->index >= (vi->i_size + PAGE_CACHE_SIZE - 1) >>
 			PAGE_CACHE_SHIFT)) {
 		unlock_page(page);
-		ntfs_debug("Write outside i_size. Returning i/o error.");
-		return -EIO;
+		ntfs_debug("Write outside i_size - truncated?");
+		return 0;
 	}
 
 	ni = NTFS_I(vi);
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/reiserfs/inode.c patched/fs/reiserfs/inode.c
--- orig/fs/reiserfs/inode.c	2003-05-21 12:54:32.000000000 -0500
+++ patched/fs/reiserfs/inode.c	2003-05-21 13:26:41.000000000 -0500
@@ -2048,8 +2048,8 @@
         last_offset = inode->i_size & (PAGE_CACHE_SIZE - 1) ;
 	/* no file contents in this page */
 	if (page->index >= end_index + 1 || !last_offset) {
-	    error =  -EIO ;
-	    goto fail ;
+	    error = 0 ;
+	    goto done ;
 	}
 	kaddr = kmap_atomic(page, KM_USER0);
 	memset(kaddr + last_offset, 0, PAGE_CACHE_SIZE-last_offset) ;
diff -urN -x genksyms -x '*.ver' -x '.patch*' -x '*.orig' orig/fs/smbfs/file.c patched/fs/smbfs/file.c
--- orig/fs/smbfs/file.c	2003-04-19 21:50:45.000000000 -0500
+++ patched/fs/smbfs/file.c	2003-05-21 13:26:41.000000000 -0500
@@ -193,7 +193,7 @@
 	offset = inode->i_size & (PAGE_CACHE_SIZE-1);
 	/* OK, are we completely out? */
 	if (page->index >= end_index+1 || !offset)
-		return -EIO;
+		return 0; /* truncated - don't care */
 do_it:
 	page_cache_get(page);
 	err = smb_writepage_sync(inode, page, 0, offset);

-- 
Matt Mackall : http://www.selenic.com : of or relating to the moon