Helps if we look _inside_ the buffer, rather than adding jeb->offset to
it. Doh.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Return -EUCLEAN on read when a bitflip was detected and corrected, so the
clients can react and eventually copy the affected block to a spare one.
Make all in kernel users aware of the change.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Hopefully the last iteration on this!

The handling of out of band data on NAND was accompanied by tons of fruitless
discussions and halfarsed patches to make it work for a particular
problem. Sufficiently annoyed by I all those "I know it better" mails and the
resonable amount of discarded "it solves my problem" patches, I finally decided
to go for the big rework. After removing the _ecc variants of mtd read/write
functions the solution to satisfy the various requirements was to refactor the
read/write _oob functions in mtd.

The major change is that read/write_oob now takes a pointer to an operation
descriptor structure "struct mtd_oob_ops".instead of having a function with at
least seven arguments.

read/write_oob which should probably renamed to a more descriptive name, can do
the following tasks:

- read/write out of band data
- read/write data content and out of band data
- read/write raw data content and out of band data (ecc disabled)

struct mtd_oob_ops has a mode field, which determines the oob handling mode.

Aside of the MTD_OOB_RAW mode, which is intended to be especially for
diagnostic purposes and some internal functions e.g. bad block table creation,
the other two modes are for mtd clients:

MTD_OOB_PLACE puts/gets the given oob data exactly to/from the place which is
described by the ooboffs and ooblen fields of the mtd_oob_ops strcuture. It's
up to the caller to make sure that the byte positions are not used by the ECC
placement algorithms.

MTD_OOB_AUTO puts/gets the given oob data automaticaly to/from the places in
the out of band area which are described by the oobfree tuples in the ecclayout
data structre which is associated to the devicee.

The decision whether data plus oob or oob only handling is done depends on the
setting of the datbuf member of the data structure. When datbuf == NULL then
the internal read/write_oob functions are selected, otherwise the read/write
data routines are invoked.

Tested on a few platforms with all variants. Please be aware of possible
regressions for your particular device / application scenario

Disclaimer: Any whining will be ignored from those who just contributed "hot
air blurb" and never sat down to tackle the underlying problem of the mess in
the NAND driver grown over time and the big chunk of work to fix up the
existing users. The problem was not the holiness of the existing MTD
interfaces. The problems was the lack of time to go for the big overhaul. It's
easy to add more mess to the existing one, but it takes alot of effort to go
for a real solution.

Improvements and bugfixes are welcome!
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Most of those macros are unused and the used ones just obfuscate
the code. Remove them and fixup all users.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The nand_oobinfo structure is not fitting the newer error correction
demands anymore. Replace it by struct nand_ecclayout and fixup the users
all over the place. Keep the nand_oobinfo based ioctl for user space
compability reasons.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The info structure for out of band data was copied into
the mtd structure. Make it a pointer and remove the ability
to set it from userspace. The position of ecc bytes is
defined by the hardware and should not be changed by software.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

A data node might not be in the fraglist; it could be f->metadata.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

This allows us to drop another pointer from the struct jffs2_raw_node_ref,
shrinking it to 8 bytes on 32-bit machines (if the TEST_TOTLEN) paranoia
check is turned off, which will be committed soon).
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Print wasted_size in scanned eraseblocks, print range correctly for
summary dirent and inode entries.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Preallocation of refs is shortly going to be a per-eraseblock thing,
rather than per-filesystem. Add the required argument to the function.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

... to jffs2_free_jeb_node_refs() since that's what it does.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

One more place where we were changing the accounting info without
actually allocating a ref for the lost space...
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Random unthinking 'cleanup' caused debug messages like this:
   Obsoleting node at 0x0006daf4 of len 0x3a4: <7>Dirtying

If messages are continuation of an existing line, they don't need
to be prefixed with KERN_DEBUG.

THINK. Or you will be replaced by a small shell script.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Another part of the preparation for switching to an array...
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

As the first step towards eliminating the ref->next_phys member and saving
memory by using an _array_ of struct jffs2_raw_node_ref per eraseblock,
stop the write functions from allocating their own refs; have them just
_reserve_ the appropriate number instead. Then jffs2_link_node_ref() can
just fill them in.

Use a linked list of pre-allocated refs in the superblock, for now. Once
we switch to an array, it'll just be a case of extending that array.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

MTD clients are agnostic of FLASH which needs ECC suppport.
Remove the functions and fixup the callers.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

The writev based write buffer implementation was far to complex as
in most use cases the write buffer had to be handled anyway.
Simplify the write buffer handling and use mtd->write instead.

From extensive testing no performance impact has been noted.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

We don't need the upper layers to deal with the physical offset. It's
_always_ c->nextblock->offset + c->sector_size - c->nextblock->free_size
so we might as well just let the actual write functions deal with that.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

o Add a flag MTD_BIT_WRITEABLE for devices that allow single bits to be
  cleared.
o Replace MTD_PROGRAM_REGIONS with a cleared MTD_BIT_WRITEABLE flag for
  STMicro and Intel Sibley flashes with internal ECC.  Those flashes
  disallow clearing of single bits, unlike regular NOR flashes, so the
  new flag models their behaviour better.
o Remove MTD_ECC.  After the STMicro/Sibley merge, this flag is only set
  and never checked.
Signed-off-by: NJoern Engel <joern@wh.fh-wedel.de>

In 2002, STMicro started producing NOR flashes with internal ECC protection
for small blocks (8 or 16 bytes).  Support for those flashes was added by me.
In 2005, Intel Sibley flashes copied this strategy and Nico added support for
those.  Merge the code for both.
Signed-off-by: NJoern Engel <joern@wh.fh-wedel.de>

At least two flashes exists that have the concept of a minimum write unit,
similar to NAND pages, but no other NAND characteristics.  Therefore, rename
the minimum write unit to "writesize" for all flashes, including NAND.
Signed-off-by: NJoern Engel <joern@wh.fh-wedel.de>

We'll be using a proper list of nodes in the jffs2_xattr_datum and
jffs2_xattr_ref structures, because the existing code to overwrite
them is just broken. Put it in the common part at the front of the
structure which is shared with the jffs2_inode_cache, so that the
jffs2_link_node_ref() function can do the right thing.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

In a couple of places, we assume that what's at the end of the
->next_in_ino list is a struct jffs2_inode_cache. Let's check
for that, since we expect it to change soon.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Let's avoid the potential for forgetting to set ref->next_in_ino, by doing
it within jffs2_link_node_ref() instead.

This highlights the ugliness of what we're currently doing with
xattr_datum and xattr_ref structures -- we should find a nicer way of
dealing with that.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

When filing REF_OBSOLETE nodes, we'd add their size to the global
'dirty_size' count, but then to the eraseblock's 'used_size' count.
That's not clever.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

I added an argument to the real function...
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Well, almost. We'll actually keep a 'TEST_TOTLEN' macro set for now, and keep
doing some paranoia checks to make sure it's all working correctly. But if
TEST_TOTLEN is unset, the size of struct jffs2_raw_node_ref drops from 16
bytes to 12 on 32-bit machines. That's a saving of about half a megabyte of
memory on the OLPC prototype board, with 125K or so nodes in its 512MiB of
flash.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

We can't use jffs2_scan_dirty_space() because it doesn't do any locking; it's
only for use at scan time -- hence the 'scan' in the name.

Also, don't allocate refs while we have c->erase_completion_lock held.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

We don't allocate this locally any more -- it's given to us and owner by
our caller. Also improve the debug messages a little.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Next step in ongoing campaign to file a struct jffs2_raw_node_ref for every
piece of dirty space in the system, so that __totlen can be killed off....
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

If __totlen is going away, we need to pass the length in separately.
Also stop callers from needlessly setting ref->next_phys to NULL,
since that's done for them... and since that'll also be going away soon.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Make sure we allocate a ref for any dirty space which exists between nodes
which we find in an eraseblock summary.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

The incoming ref_totlen() calculation is going to rely on the existence
of nodes which cover all dirty space. We can't just tweak the accounting
data any more; we have to call jffs2_scan_dirty_space() to do it.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

To eliminate the __totlen field from struct jffs2_raw_node_ref, we need
to allocate nodes for dirty space instead of just tweaking the accounting
data. Introduce jffs2_scan_dirty_space() in preparation for that.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

For RWCOMPAT and ROCOMPAT nodes, we should still allow the mount to
succeed. Just abandon the summary and fall through to the full scan.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>