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: Thomas 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: Thomas 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: Thomas 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: Thomas Gleixner <tglx@linutronix.de>
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: David 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: David 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: David Woodhouse <dwmw2@infradead.org>
MTD clients are agnostic of FLASH which needs ECC suppport.
Remove the functions and fixup the callers.
Signed-off-by: Thomas 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: Thomas 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: David Woodhouse <dwmw2@infradead.org>
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: Joern 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: Joern Engel <joern@wh.fh-wedel.de>
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: David 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: David 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: David Woodhouse <dwmw2@infradead.org>
This is the fs/ part of the big kfree cleanup patch.
Remove pointless checks for NULL prior to calling kfree() in fs/.
Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
- assume wbuf may be of size which is not power of 2
- don't make strange assumption about not padding wbuf for DataFlash
- use wbuf = DataFlash page and eraseblock >= 8 Dataflash pages
From: Peter Menzebach <pm-mtd@mw-itcon.de>
Acked-by: Artem B. Bityutskiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Simplify the debugging code further.
Update the TODO list
Signed-off-by: Artem B. Bityutskiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Akinobu Mita
Thomas Gleixner
David Woodhouse
Joern Engel
Linus Torvalds
Jesper Juhl
Thomas Gleixner
Artem B. Bityutskiy