Move BKL into ->put_super from the only caller.  A couple of
filesystems had trivial enough ->put_super (only kfree and NULLing of
s_fs_info + stuff in there) to not get any locking: coda, cramfs, efs,
hugetlbfs, omfs, qnx4, shmem, all others got the full treatment.  Most
of them probably don't need it, but I'd rather sort that out individually.
Preferably after all the other BKL pushdowns in that area.

[AV: original used to move lock_super() down as well; these changes are
removed since we don't do lock_super() at all in generic_shutdown_super()
now]
[AV: fuse, btrfs and xfs are known to need no damn BKL, exempt]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Make sure a superblock really is writeable by checking MS_RDONLY
under s_umount.  sync_filesystems needed some re-arragement for
that, but all but one sync_filesystem caller had the correct locking
already so that we could add that check there.  cachefiles grew
s_umount locking.

I've also added a WARN_ON to sync_filesystem to assert this for
future callers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

Change the page_mkwrite prototype to take a struct vm_fault, and return
VM_FAULT_xxx flags.  There should be no functional change.

This makes it possible to return much more detailed error information to
the VM (and also can provide more information eg.  virtual_address to the
driver, which might be important in some special cases).

This is required for a subsequent fix.  And will also make it easier to
merge page_mkwrite() with fault() in future.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Artem Bityutskiy <dedekind@infradead.org>
Cc: Felix Blyakher <felixb@sgi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

UBIFS did not recovery in a situation in which it could
have. The relevant function assumed there could not be
more nodes in an eraseblock after a corrupted node, but
in fact the last (NAND) page written might contain anything.
The correct approach is to check for empty space (0xFF bytes)
from then on.
Signed-off-by: NAdrian Hunter <adrian.hunter@nokia.com>

Signed-off-by: NMatt LaPlante <kernel1@cyberdogtech.com>
Acked-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

simple_set_mnt() is defined as returning 'int' but always returns 0.
Callers assume simple_set_mnt() never fails and don't properly cleanup if
it were to _ever_ fail.  For instance, get_sb_single() and get_sb_nodev()
should:

        up_write(sb->s_unmount);
        deactivate_super(sb);

if simple_set_mnt() fails.

Since simple_set_mnt() never fails, would be cleaner if it did not
return anything.

[akpm@linux-foundation.org: fix build]
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Now UBIFS is supported by u-boot. If we ever decide to change the
media format, then people will have to upgrade their u-boots to
mount new format images. However, very often it is possible to
preserve R/O forward-compatibility, even though the write
forward-compatibility is not preserved.

This patch introduces a new super-block field which stores the
R/O compatibility version.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Acked-by: NAdrian Hunter <Adrian.Hunter@nokia.com>

fs/ubifs/super.c: In function ‘ubifs_show_options’:
fs/ubifs/super.c:425: warning: format not a string literal and no format arguments
fs/ubifs/super.c: In function ‘mount_ubifs’:
fs/ubifs/super.c:1204: warning: format not a string literal and no format arguments
fs/ubifs/super.c: In function ‘ubifs_remount_rw’:
fs/ubifs/super.c:1557: warning: format not a string literal and no format arguments
Signed-off-by: NAdrian Hunter <adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The 'joinup()' function cannot deal with situations when nodes
go in reverse order - it just leaves them in this order. This
patch implement full nodes sorting using n*log(n) algorithm.
It sorts data nodes for bulk-read, and direntry nodes for
readdir().
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch introduces a helpful @c->idx_leb_size variable.
The patch also fixes some spelling issues and makes comments
use "LEB" instead of "eraseblock", which is more correct.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When writing lprop nodes, do not forget to set @from to 0 when
switching the LEB. This fixes the following bug:

UBIFS error (pid 27768): ubifs_leb_write: writing -15456 bytes at 16:15880, error -22
UBIFS error (pid 27768): do_commit: commit failed, error -22
UBIFS warning (pid 27768): ubifs_ro_mode: switched to read-only mode, error -22
Pid: 27768, comm: freespace Not tainted 2.6.29-rc4-ubifs-2.6 #43
Call Trace:
 [<ffffffffa00c46d6>] ubifs_ro_mode+0x54/0x56 [ubifs]
 [<ffffffffa00cfa16>] do_commit+0x4f5/0x50a [ubifs]
 [<ffffffffa00cfae7>] ubifs_run_commit+0xbc/0xdb [ubifs]
 [<ffffffffa00d42b9>] ubifs_budget_space+0x742/0x9ed [ubifs]
 [<ffffffff812daf45>] ? __mutex_lock_common+0x361/0x3ae
 [<ffffffffa00bc437>] ? ubifs_write_begin+0x18d/0x44c [ubifs]
 [<ffffffffa00bc5cb>] ubifs_write_begin+0x321/0x44c [ubifs]
 [<ffffffff8106222b>] ? trace_hardirqs_on_caller+0x1f/0x14d
 [<ffffffff81097ce2>] generic_file_buffered_write+0x12f/0x2d9
 [<ffffffff8109828d>] __generic_file_aio_write_nolock+0x261/0x295
 [<ffffffff81098aff>] generic_file_aio_write+0x69/0xc5
 [<ffffffffa00bb914>] ubifs_aio_write+0x14c/0x19e [ubifs]
 [<ffffffff810c8f42>] do_sync_write+0xe7/0x12d
 [<ffffffff81055378>] ? autoremove_wake_function+0x0/0x38
 [<ffffffff81149edc>] ? security_file_permission+0x11/0x13
 [<ffffffff810c9827>] vfs_write+0xab/0x105
 [<ffffffff810c9945>] sys_write+0x47/0x6f
 [<ffffffff8100c35b>] system_call_fastpath+0x16/0x1b
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Empty journal head LEBs are accounted as taken empty as well, so
the GC LEB does not have to be the only taken empty LEB when
nounting/remounting.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

UBIFS fast path in write_begin may mark a page up to date
and then discover that there may not be enough space to do
the write, and so fall back to a slow path.  The slow path
tries harder, but may still find no space - leaving the page
marked up to date, when it is not.  This patch ensures that
the page is marked not up to date in that case.

The bug that this patch fixes becomes evident when the write
is into a hole (sparse file) or is at the end of the file
and a subsequent read is off the end of the file.  In both
cases, the file system should return zeros but was instead
returning the page that had not been written because the
file system was out of space.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

... which should be uint32_t, not int.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Make 'ubifs_find_free_space()' return offset where free space starts,
rather than the amount of free space. This is just more appropriat
for its caller.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Trivial cleanup, list_del(); list_add{,_tail}() is equivalent
to list_move{,_tail}(). Semantic patch for coccinelle can be
found at www.cccmz.de/~snakebyte/list_move_tail.spatch
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The debugging function dbg_chk_lpt_sz() was not working
correctly for small min_io_unit size e.g. NOR flash.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This UBIFS feature has never worked properly, and it was a mistake
to add it because we simply have no use-cases. So, lets still accept
the fast_unmount mount option, but ignore it. This does not change
much, because UBIFS commit in sync_fs anyway, and sync_fs is called
while unmounting.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When mounting/re-mounting, UBIFS returns EINVAL even if the ENOSPC
or EROFS codes are are much better, just because we have not found
references to ENOSPC/EROFS in mount (2) man pages. This patch
changes this behaviour and makes UBIFS return real error code,
because:

1. It is just less confusing and more logical
2. mount is not described in SuSv3, so it seems to be not really
   well-standartized
3. we do not cover all cases, and any random undocumented in man
   pages error code may be returned anyway
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

- preserve the idx_gc list - it will be needed in the same
state, should UBIFS be remounted rw again
- prevent remounting ro if we have switched to read only
mode (due to a fatal error)
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

All writes go through wbufs so they must be sync'd
after syncing inodes and pages.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The function to traverse and dirty the LPT was still not
dirtying all nodes, with the result that the LPT could
run out of space.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When data CRC checking is disabled, UBIFS returns incorrect return
code from the 'try_read_node()' function (0 instead of 1, which means
CRC error), which make the caller re-read the data node again, but using
a different code patch, so the second read is fine. Thus, we read the
same node twice. And the result of this is that UBIFS is slower
with no_chk_data_crc option than it is with chk_data_crc option.
This patches fixes the problem.
Reported-by: NReuben Dowle <Reuben.Dowle@navico.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

I introduce wrong assertions in one of the previous commits, this
patch fixes them.

Also, initialize debugfs after the debugging check. This is a little
nicer because we want the FS data to be accessible to external users
after everything has been initialized.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When mounting read-only the orphan area head is
not initialized.  It must be initialized when
remounting read/write, but it was not.  This patch
fixes that.

[Artem: sorry, added comment tweaking noise]
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When we mount UBIFS, GC LEB may contain out-of-date information,
and UBIFS should update lprops and set free space for thei LEB.
Currently UBIFS does this only if mounted R/W. But for R/O mount
we have to do the same, because otherwise we will have incorrect
FS free space reported to user-space.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

We observe space corrupted accounting when re-mounting. So add some
debbugging checks to catch problems like this.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

When freeing the c->idx_lebs list, we have to release the LEBs as well,
because we might be called from mount to read-only mode code. Otherwise
the LEBs stay taken forever, which may cause problems when we re-mount
back ro RW mode.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This patch simplifies lock_[23]_inodes functions. We do not have
to care about locking order, because UBIFS does this for @i_mutex
and this is enough. Thanks to Al Viro for suggesting this.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Just add more commentaries. Also some commentary fixes for
lprops flags.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

UBIFS wrongly tells UBI that all data is short term. Use proper
hints instead. Thanks to Xiaochuan-Xu for noticing this.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Mark super, file, and inode operation structcutes with 'const'.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

VFS calls '->sync_fs()' twice - first time with @wait = 0, second
time with @wait = 1. As a result, we may commit and synchronize
write-buffers twice. Avoid doing this by returning immediatelly if
@wait = 0.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

WB_SYNC_HOLD is going to be zapped so we should not use it. Use
%WB_SYNC_NONE instead. Here is what akpm said:

"I think I'll just switch that to WB_SYNC_NONE.  The `wait==0' mode is
just an advisory thing to help the fs shove lots of data into the
queues.  If some gets missed then it'll be picked up on the second
->sync_fs call, with wait==1."

Thanks to Randy Dunlap for catching this.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- (better, more, bigger ...) then -> (...) than
Signed-off-by: NFrederik Schwarzer <schwarzerf@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

With the write_begin/write_end aops, page_symlink was broken because it
could no longer pass a GFP_NOFS type mask into the point where the
allocations happened.  They are done in write_begin, which would always
assume that the filesystem can be entered from reclaim.  This bug could
cause filesystem deadlocks.

The funny thing with having a gfp_t mask there is that it doesn't really
allow the caller to arbitrarily tinker with the context in which it can be
called.  It couldn't ever be GFP_ATOMIC, for example, because it needs to
take the page lock.  The only thing any callers care about is __GFP_FS
anyway, so turn that into a single flag.

Add a new flag for write_begin, AOP_FLAG_NOFS.  Filesystems can now act on
this flag in their write_begin function.  Change __grab_cache_page to
accept a nofs argument as well, to honour that flag (while we're there,
change the name to grab_cache_page_write_begin which is more instructive
and does away with random leading underscores).

This is really a more flexible way to go in the end anyway -- if a
filesystem happens to want any extra allocations aside from the pagecache
ones in ints write_begin function, it may now use GFP_KERNEL (rather than
GFP_NOFS) for common case allocations (eg.  ocfs2_alloc_write_ctxt, for a
random example).

[kosaki.motohiro@jp.fujitsu.com: fix ubifs]
[kosaki.motohiro@jp.fujitsu.com: fix fuse]
Signed-off-by: NNick Piggin <npiggin@suse.de>
Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org>		[2.6.28.x]
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
[ Cleaned up the calling convention: just pass in the AOP flags
  untouched to the grab_cache_page_write_begin() function.  That
  just simplifies everybody, and may even allow future expansion of the
  logic.   - Linus ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>