No need to check for all-zero header since the header cannot
be zero due to other checks.

Replace the all-zero header check in readinode.c with a
check for the magic word.
Signed-off-by: NJoakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

We originally used to read every node and allocate a jffs2_tmp_dnode_info
structure for each, before processing them in (reverse) version order
and discarding the ones which are obsoleted by later nodes.

With huge logfiles, this behaviour caused memory problems. For example, a
file involved in OLPC trac #1292 has 1822391 nodes, and would cause the XO
machine to run out of memory during the first stage of read_inode().

Instead of just inserting nodes into a tree in version order as we find
them, we now put them into a tree in order of their offset within the
file, which allows us to immediately discard nodes which are completely
obsoleted.

We don't use a full tree with 'fragments' pointing to the real data
structure, as we do in the normal fragtree. We sort only on the start
address, and add an 'overlapped' flag to the tmp_dnode_info to indicate
that the node in question is (partially) overlapped by another.

When the scan is complete, we start at the end of the file, adding each
node to a real fragtree as before. Where the node is non-overlapped, we
just add it (it doesn't matter that it's not the latest version; there is
no overlap). When the node at the end of the tree _is_ overlapped, we sort
it and all its overlapping nodes into version order and then add them to
the fragtree in that order.

This 'early discard' reduces the peak allocation of tmp_dnode_info
structures from 1.8M to a mere 62872 (3.5%) in the degenerate case
referenced above.

This version of the patch also correctly rememembers the highest node
version# seen for an inode when it's scanned.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

We should never find the unchecked size is non-zero after we've finished
checking all inodes. If it happens, used to BUG(), leaving the alloc_sem
held and deadlocking. Instead, just return -ENOSPC after complaining. The
GC thread will die, but read-only operation should be able to continue and
the file system should be unmountable.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

When compiling a LE-capable JFFS2 on PowerPC, wbuf.c fails to compile:

fs/jffs2/wbuf.c:973: error: braced-group within expression allowed only inside a function
fs/jffs2/wbuf.c:973: error: initializer element is not constant
fs/jffs2/wbuf.c:973: error: (near initialization for ‘oob_cleanmarker.magic’)
fs/jffs2/wbuf.c:974: error: braced-group within expression allowed only inside a function
fs/jffs2/wbuf.c:974: error: initializer element is not constant
fs/jffs2/wbuf.c:974: error: (near initialization for ‘oob_cleanmarker.nodetype’)
fs/jffs2/wbuf.c:975: error: braced-group within expression allowed only inside a function
fs/jffs2/wbuf.c:976: error: initializer element is not constant
fs/jffs2/wbuf.c:976: error: (near initialization for ‘oob_cleanmarker.totlen’)

Provide constant_cpu_to_je{16,32} functions, and use them for initialising the
offending structure.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Signed-off-by: NJoakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Remove excessive scanning of empty flash after a clean
marker for users of the point/unpoint method. cfi_cmdset_0001
uses point/unpoint by default iff flash mapping is linear.
The speedup is several orders of magnitude if FS is less than
half full.
Signed-off-by: NJoakim Tjernlund <Joakim.Tjernlund@transmode.se>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

In read inode we have an optimization which prevents one
min. I/O unit (e.g. NAND page) to be read more then once.

Namely, at the beginning we do not know which node type we read,
so we read so we assume we read the directory entry, because it
has the smallest node header. When we read it, we read up to the
next min. I/O unit, just because if later we'll need to read more,
we already have this data.

If it turns out to be that the node is not directory entry, and
we need more data, and we did not read it because it sits in the
next min. I/O unit, we read the whole next (or several next)
min. I/O unit(s). And if it happens to be that we read a data node,
and we've read part of its data, we calculate partial CRC.
So if later we need to check data CRC, we'll only read the rest
of the data from further min. I/O units and continue CRC checking.

This code was a bit messy and buggy. The bug was that it assumed
relatively large min. I/O unit, so that the largest node header
could overlap only one min. I/O unit boundary.

This parch clean-ups the code a bit and fixes this bug.
The patch was not tested on flash with small min. I/O unit, like
NOR-ECC, nut it was tested on NAND with 512 bytes NAND page, so
it at least does not break NAND. It was also tested with mtdram
so it should not break NOR.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

After a write error, any data in the write buffer must
be relocated.  This is handled by the jffs2_wbuf_recover
function.  This function does not fix up the erase block
summary information that is collected for writing at the
end of the block, which results in an incorrect summary
(or BUG if the summary was found to be empty).

As the summary is not essential (it is an optimisation),
it may be disabled for the current erase block when this
situation arises.  This patch does that.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

If a write error occurs, the affected block is placed on the
bad_used_list.  In the case that the write error occured
when writing summary data the block was also being placed on
the dirty_list, which caused list corruption and ultimately
a soft lockup in jffs2_mark_node_obsolete. This fixes that.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

When the MTD driver returns write failure, the following deadlock
occurs:

We are in __jffs2_flush_wbuf(), we hold &c->wbuf_sem. Write failure.
jffs2_wbuf_recover()->jffs2_reserve_space_gc()->jffs2_do_reserve_space()
->jffs2_erase_pending_blocks()->jffs2_flash_read()

and it tries to lock &c->wbuf_sem again. Deadlock.
Reported-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Check the node CRC on scan before doing anything else with the node.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Delete everything related to the apparently non-existent kernel config
option JFFS2_PROC.
Signed-off-by: NRobert P. J. Day <rpjday@mindspring.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

  Delete the obsolete source file fs/jffs2/comprtest.c.
Signed-off-by: NRobert P. J. Day <rpjday@mindspring.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

New bad eraseblock is an event which is important enough to be printed
about.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Due to a poor choice of CRC32 seed, a node header which is all zeroes
would pass the CRC32 check. Explicitly check for this case, and treat it
as we do a CRC failure.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

The garbage collection thread is strictly an optimisation. Everything it
does would also be done just-in-time in the context of something in
userspace trying to access the file system.

Sometimes, however, it's a pessimisation. Especially during early boot
when it's checksumming nodes and scanning inodes which are shortly going
to be pulled in by read_inode anyway. We end up building the rbtree of
node coverage twice for the same inode.

By switching to yield() instead of cond_resched() in the main loop, we
observe boot times on the OLPC system going down from about 100 seconds to
60.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

For the case when nand_write_page fail with -EIO for the first page in an
eraseblock, jffs2_wbuf_recover ends up producing a BUG in jffs2_block_refile
as jeb->first_node is not yet set up (it's set up later in jffs2_wbuf_recover).
This BUG is not really a bug; it's just jffs2_wbuf_recover calling
jffs2_block_refile with the wrong second parameter.
This patch takes care of this situation.
Signed-off-by: NVitaly Wool <vwool@ru.mvista.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

fs/jffs2/wbuf.c: In function 'jffs2_check_oob_empty':
fs/jffs2/wbuf.c:993: warning: format '%d' expects type 'int', but argument 3 has type 'size_t'
fs/jffs2/wbuf.c:993: warning: format '%d' expects type 'int', but argument 4 has type 'size_t'
fs/jffs2/wbuf.c: In function 'jffs2_check_nand_cleanmarker':
fs/jffs2/wbuf.c:1036: warning: format '%d' expects type 'int', but argument 3 has type 'size_t'
fs/jffs2/wbuf.c:1036: warning: format '%d' expects type 'int', but argument 4 has type 'size_t'
fs/jffs2/wbuf.c: In function 'jffs2_write_nand_cleanmarker':
fs/jffs2/wbuf.c:1062: warning: format '%d' expects type 'int', but argument 3 has type 'size_t'
fs/jffs2/wbuf.c:1062: warning: format '%d' expects type 'int', but argument 4 has type 'size_t'
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there.  Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm.  I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: NTim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch is inspired by Arjan's "Patch series to mark struct
file_operations and struct inode_operations const".

Compile tested with gcc & sparse.
Signed-off-by: NJosef 'Jeff' Sipek <jsipek@cs.sunysb.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Nowadays MTD supports an MTD_OOB_AUTO option which allows users
to access free bytes in NAND's OOB as a contiguous buffer, although
it may be highly discontinuous.

This patch teaches JFFS2 to use this nice feature instead of the
old MTD_OOB_PLACE option. This for example caused problems with
OneNAND. Now JFFS2 does not care how are the free bytes situated.

This may change position of the clean marker on some flashes,
but this is not a problem. JFFS2 will just re-erase the empty
eraseblocks and write the new (correct) clean marker.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

If  jffs2_sum_init()  fails,  c->blocks is not freed neither in
jffs2_do_mount_fs() nor in jffs2_do_fill_super().
Signed-off-by: NDmitry Adamushko <dmitry.adamushko@gmail.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

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

Don't use ref->flash_offset directly in debugging code, use the ref_offset macro instead.
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NArtem Bityutskiy <dedekind@infradead.org>

Make JFFS2 nicer and teach it to call cond_resched() in loops
which may be quite large.
Signed-off-by: NArtem Bityutskiy <dedekind@infradead.org>

Signed-off-by: NAmit Choudhary <amit2030@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

We observe soft lockups when doing heavy test which creates
directory with a lot of direntries and deletes them. This
cycle is the reason fo this. Make it nicer and add cond_resched()
inside of it.
Signed-off-by: NArtem Bityutskiy <dedekind@infradead.org>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Replace kmalloc+memset with kzalloc
Signed-off-by: NYan Burman <burman.yan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Signed-off-by: NJosef Sipek <jsipek@fsl.cs.sunysb.edu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.

[akpm@osdl.org: fix ueagle driver]
Signed-off-by: NNigel Cunningham <nigel@suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Replace all uses of kmem_cache_t with struct kmem_cache.

The patch was generated using the following script:

	#!/bin/sh
	#
	# Replace one string by another in all the kernel sources.
	#

	set -e

	for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
		quilt add $file
		sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
		mv /tmp/$$ $file
		quilt refresh
	done

The script was run like this

	sh replace kmem_cache_t "struct kmem_cache"
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

SLAB_KERNEL is an alias of GFP_KERNEL.
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

get_mtd_device() returns NULL in case of any failure. Teach it to return an
error code instead. Fix all users as well.
Signed-off-by: NArtem Bityutskiy <dedekind@infradead.org>

As was discussed between Ricard Wanderlöf, David Woodhouse, Artem 
Bityutskiy and me, the current API for reading/writing OOB is confusing. 

The thing that introduces confusion is the need to specify ops.len 
together with ops.ooblen for reads/writes that concern only OOB not data 
area. So, ops.len is overloaded: when ops.datbuf != NULL it serves to 
specify the length of the data read, and when ops.datbuf == NULL, it 
serves to specify the full OOB read length.

The patch inlined below is the slightly updated version of the previous 
patch serving the same purpose, but with the new Artem's comments taken 
into account.

Artem, BTW, thanks a lot for your valuable input!
Signed-off-by: NVitaly Wool <vwool@ru.mvista.com>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

typo fix: noticed this typo while reading the patch
"jffs2: fix symlink error handling"
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Use rb_first() and rb_last() to implement frag_first() and frag_last().
Signed-off-by: NAkinbou Mita <akinobu.mita@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

gcc emits the following warning on a 'allmodconfig' build:

fs/jffs2/xattr.c: In function ‘unrefer_xattr_datum’:
fs/jffs2/xattr.c:402: warning: unused variable ‘version’
fs/jffs2/xattr.c:402: warning: unused variable ‘xid’

Given that these variables are only used in the debug printk, and they
merely remove a deref, we can easily kill the warning by adding the
derefs to the debug printk.
Signed-off-by: NJeff Garzik <jeff@garzik.org>
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>