Reclaim will be leaving shadow entries in the page cache radix tree upon
evicting the real page.  As those pages are found from the LRU, an
iput() can lead to the inode being freed concurrently.  At this point,
reclaim must no longer install shadow pages because the inode freeing
code needs to ensure the page tree is really empty.

Add an address_space flag, AS_EXITING, that the inode freeing code sets
under the tree lock before doing the final truncate.  Reclaim will check
for this flag before installing shadow pages.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NRik van Riel <riel@redhat.com>
Reviewed-by: NMinchan Kim <minchan@kernel.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Metin Doslu <metin@citusdata.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Ozgun Erdogan <ozgun@citusdata.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <klamm@yandex-team.ru>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

UDF has two types of files - files with data stored in inode (ICB in
UDF terminology) and files with data stored in external data blocks. We
convert file from in-inode format to external format in
udf_file_aio_write() when we find out data won't fit into inode any
longer. However the following race between two O_APPEND writes can happen:

CPU1					CPU2
udf_file_aio_write()			udf_file_aio_write()
  down_write(&iinfo->i_data_sem);
  checks that i_size + count1 fits within inode
    => no need to convert
  up_write(&iinfo->i_data_sem);
					  down_write(&iinfo->i_data_sem);
					  checks that i_size + count2 fits
					    within inode => no need to convert
					  up_write(&iinfo->i_data_sem);
  generic_file_aio_write()
    - extends file by count1 bytes
					  generic_file_aio_write()
					    - extends file by count2 bytes

Clearly if count1 + count2 doesn't fit into the inode, we overwrite
kernel buffers beyond inode, possibly corrupting the filesystem as well.

Fix the problem by acquiring i_mutex before checking whether write fits
into the inode and using __generic_file_aio_write() afterwards which
puts check and write into one critical section.
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NJan Kara <jack@suse.cz>

Lockdep is complaining about UDF:
=============================================
[ INFO: possible recursive locking detected ]
3.12.0+ #16 Not tainted
---------------------------------------------
ln/7386 is trying to acquire lock:
 (&ei->i_data_sem){+.+...}, at: [<ffffffff8142f06d>] udf_get_block+0x8d/0x130

but task is already holding lock:
 (&ei->i_data_sem){+.+...}, at: [<ffffffff81431a8d>] udf_symlink+0x8d/0x690

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&ei->i_data_sem);
  lock(&ei->i_data_sem);

 *** DEADLOCK ***

This is because we hold i_data_sem of the symlink inode while calling
udf_add_entry() for the directory. I don't think this can ever lead to
deadlocks since we never hold i_data_sem for two inodes in any other
place.

The fix is simple - move unlock of i_data_sem for symlink inode up. We
don't need it for anything when linking symlink inode to directory.
Reported-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NJan Kara <jack@suse.cz>

The UDF driver was not strict enough about checking the IDs in the
VSDs when mounting, which resulted in reading through all the sectors
of the block device in some unfortunate cases. Eg, trying to mount my
uninitialized 200G SSD partition (all 0xFF bytes) took ~350 minutes to
fail, because the code expected some of the valid IDs or a zero byte.
During this, the mount couldn't be killed, sync from the cmdline
blocked, and the machine froze into the shutdown. Valid filesystems
(extX, btrfs, ntfs) were rejected by the mere accident of having a
zero byte at just the right place in some of their sectors, close
enough to the beginning not to generate excess I/O. The fix adds a
hard limit on the VSD sector offset, adds the two missing VSD IDs, and
stops scanning when encountering an invalid ID. Also replaced the
magic number 32768 with a more meaningful #define, and supressed the
bogus message about failing to read the first sector if no UDF fs was
detected.
Signed-off-by: NPeter A. Felvegi <petschy@gmail.com>
Signed-off-by: NJan Kara <jack@suse.cz>

A user has reported an oops in udf_statfs() that was caused by
numOfPartitions entry in LVID structure being corrupted. Fix the problem
by verifying whether numOfPartitions makes sense at least to the extent
that LVID fits into a single block as it should.
Reported-by: NJuergen Weigert <jw@suse.com>
Signed-off-by: NJan Kara <jack@suse.cz>

truncate_pagecache() doesn't care about old size since commit
cedabed4 ("vfs: Fix vmtruncate() regression").  Let's drop it.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Refuse RW mount of udf filesystem. So far we just silently changed it
to RO mount but when the media is writeable, block layer won't notice
this change and thus will think device is used RW and will block eject
button of the drive. That is unexpected by users because for
non-writeable media eject button works just fine.

Userspace mount(8) command handles this just fine and retries mounting
with MS_RDONLY set so userspace shouldn't see any regression.  Plus any
tool mounting udf is likely confronted with the case of read-only
media where block layer already refuses to mount the filesystem without
MS_RDONLY set so our behavior shouldn't be anything new for it.
Reported-by: NHui Wang <hui.wang@canonical.com>
Signed-off-by: NJan Kara <jack@suse.cz>

Change all function used in filesystem discovery during mount to user
standard kernel return values - -errno on error, 0 on success instead
of 1 on failure and 0 on success. This allows us to pass error number
(not just failure / success) so we can abort device scanning earlier
in case of errors like EIO or ENOMEM . Also we will be able to return
EROFS in case writeable mount is requested but writing isn't supported.
Signed-off-by: NJan Kara <jack@suse.cz>

This code doesn't serve any purpose anymore, since the aio retry
infrastructure has been removed.

This change should be safe because aio_read/write are also used for
synchronous IO, and called from do_sync_read()/do_sync_write() - and
there's no looping done in the sync case (the read and write syscalls).
Signed-off-by: NKent Overstreet <koverstreet@google.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: NBenjamin LaHaise <bcrl@kvack.org>

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

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

Faster kernel compiles by way of fewer unnecessary includes.

[akpm@linux-foundation.org: fix fallout]
[akpm@linux-foundation.org: fix build]
Signed-off-by: NKent Overstreet <koverstreet@google.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Somehow I failed to add the MODULE_ALIAS_FS for cifs, hostfs, hpfs,
squashfs, and udf despite what I thought were my careful checks :(

Add them now.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

According to SUSv3:

[EACCES] Permission denied. An attempt was made to access a file in a way
forbidden by its file access permissions.

[EPERM] Operation not permitted. An attempt was made to perform an operation
limited to processes with appropriate privileges or to the owner of a file
or other resource.

So -EPERM should be returned if capability checks fails.

Strictly speaking this is an API change since the error code user sees is
altered.
Signed-off-by: NZhao Hongjiang <zhaohongjiang@huawei.com>
Acked-by: NJan Kara <jack@suse.cz>
Acked-by: NSteven Whitehouse <swhiteho@redhat.com>
Acked-by: NIan Kent <raven@themaw.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This patch is a follow up on below patch:

[PATCH] exportfs: add FILEID_INVALID to indicate invalid fid_type
commit: 216b6cbdSigned-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NVivek Trivedi <t.vivek@samsung.com>
Acked-by: NSteven Whitehouse <swhiteho@redhat.com>
Acked-by: NSage Weil <sage@inktank.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

s_extLength was assigned to but the value was never really used. So
just remove the field.
Signed-off-by: NJan Kara <jack@suse.cz>

struct udf_bitmap has array of buffer pointers attached to it. The code
unnecessarily used s_block_bitmap as a pointer to the array instead of
the standard trick of using 0 length array in the declaration. Change
that to make code more readable and actually shrink the structure by one
pointer.
Signed-off-by: NJan Kara <jack@suse.cz>

For large UDF filesystems with 512-byte blocks the number of necessary
bitmap blocks is larger than 2^16 so s_nr_groups in udf_bitmap overflows
(the number will overflow for filesystems larger than 128 GB with
512-byte blocks). That results in ENOSPC errors despite the filesystem
has plenty of free space.

Fix the problem by changing s_nr_groups' type to 'int'. That is enough
even for filesystems 2^32 blocks (UDF maximum) and 512-byte blocksize.

Reported-and-tested-by: v10lator@myway.de
Signed-off-by: NJan Kara <jack@suse.cz>

This patch implements extent caching in case of file reading.
While reading a file, currently, UDF reads metadata serially
which takes a lot of time depending on the number of extents present
in the file. Caching last accessd extent improves metadata read time.
Instead of reading file metadata from start, now we read from
the cached extent.

This patch considerably improves the time spent by CPU in kernel mode.
For example, while reading a 10.9 GB file using dd:
Time before applying patch:
11677022208 bytes (10.9GB) copied, 1529.748921 seconds, 7.3MB/s
real    25m 29.85s
user    0m 12.41s
sys     15m 34.75s

Time after applying patch:
11677022208 bytes (10.9GB) copied, 1469.338231 seconds, 7.6MB/s
real    24m 29.44s
user    0m 15.73s
sys     3m 27.61s

[JK: Fix bh refcounting issues, simplify initialization]
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAshish Sangwan <a.sangwan@samsung.com>
Signed-off-by: NBonggil Bak <bgbak@samsung.com>
Signed-off-by: NJan Kara <jack@suse.cz>

So far we just marked the buffer as dirty and left writing on flusher thread
but especially on opening that opens possible race window where we could write
other modified fs structures to disk before we mark filesystem as open. So sync
LVID buffer to disk after opening and closing fs.
Reported-by: NSteve Nickel <snickel58@gmail.com>
Signed-off-by: NJan Kara <jack@suse.cz>

This patch fixes a regression caused by commit bff943af "udf: Fix memory
leak when mounting" due to which it was triggering a kernel null point
dereference in case of interrupted mount OR when allocating memory to
sbi->s_partmaps failed in function udf_sb_alloc_partition_maps.
Reported-and-tested-by: NJames Hogan <james@albanarts.com>
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAshish Sangwan <a.sangwan@samsung.com>
Signed-off-by: NJan Kara <jack@suse.cz>

The variable last_block is not needed.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAshish Sangwan <a.sangwan@samsung.com>
Signed-off-by: NJan Kara <jack@suse.cz>

Incrementing lenExtents even while writing to a hole is bad
for performance as calls to udf_discard_prealloc and
udf_truncate_tail_extent would not return from start if
isize != lenExtents
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAshish Sangwan <a.sangwan@samsung.com>
Signed-off-by: NJan Kara <jack@suse.cz>

Need to brelse the buffer_head stored in cur_epos and next_epos.
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAshish Sangwan <a.sangwan@samsung.com>
Signed-off-by: NJan Kara <jack@suse.cz>

There's no reason to call rcu_barrier() on every
deactivate_locked_super().  We only need to make sure that all delayed rcu
free inodes are flushed before we destroy related cache.

Removing rcu_barrier() from deactivate_locked_super() affects some fast
paths.  E.g.  on my machine exit_group() of a last process in IPC
namespace takes 0.07538s.  rcu_barrier() takes 0.05188s of that time.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Cc: Jan Kara <jack@suse.cz>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

Add support for the O_DIRECT flag.  There are two cases to deal with:

1. Small files stored in the ICB (inode control block?): just return 0
from the new udf_adinicb_direct_IO() handler to fall back to buffered
I/O.

2. Larger files, not stored in the ICB: nothing special here.  Just call
blockdev_direct_IO() from our new udf_direct_IO() handler and tidy up
any blocks instantiated outside i_size on error.  This is pretty
standard.  Factor error handling code out of udf_write_begin() into new
function udf_write_failed() so it can also be called by udf_direct_IO().

Also change the whitespace in udf_aops to make it a bit neater.
Signed-off-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NJan Kara <jack@suse.cz>

When a file is stored in ICB (inode), we overwrite part of the file, and
the page containing file's data is not in page cache, we end up corrupting
file's data by overwriting them with zeros. The problem is we use
simple_write_begin() which simply zeroes parts of the page which are not
written to. The problem has been introduced by be021ee4 (udf: convert to
new aops).

Fix the problem by providing a ->write_begin function which makes the page
properly uptodate.

CC: <stable@vger.kernel.org> # >= 2.6.24
Reported-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NJan Kara <jack@suse.cz>

Use mpage_writepages() instead of multiple calls to udf_writepage()
to make performance higher.

*Write Speed with writepage() =
 RecSize     ReadSpeed    WriteSpeed  RanReadSpeed RanWriteSpeed
10485760    0.00MB/sec    8.56MB/sec    0.00MB/sec    8.20MB/sec
 1048576    0.00MB/sec    8.57MB/sec    0.00MB/sec    6.42MB/sec
  524288    0.00MB/sec    8.59MB/sec    0.00MB/sec    5.24MB/sec
  262144    0.00MB/sec    8.59MB/sec    0.00MB/sec    4.17MB/sec
  131072    0.00MB/sec    8.53MB/sec    0.00MB/sec    3.32MB/sec
   65536    0.00MB/sec    8.49MB/sec    0.00MB/sec    2.31MB/sec

*Write Speed with writepages()
RecSize     ReadSpeed    WriteSpeed  RanReadSpeed RanWriteSpeed
10485760    0.00MB/sec    9.88MB/sec    0.00MB/sec    9.60MB/sec
 1048576    0.00MB/sec    9.95MB/sec    0.00MB/sec    7.52MB/sec
  524288    0.00MB/sec    9.98MB/sec    0.00MB/sec    6.16MB/sec
  262144    0.00MB/sec    9.90MB/sec    0.00MB/sec    4.98MB/sec
  131072    0.00MB/sec    9.89MB/sec    0.00MB/sec    3.78MB/sec
   65536    0.00MB/sec    9.81MB/sec    0.00MB/sec    2.50MB/sec

There is about 1.4MB/sec speed improvement over 8.5MB/sec,
which comes out around 16% improvement.
Signed-off-by: NNamjae Jeon <linkinjeon@gmail.com>
Signed-off-by: NAshish Sangwan <ashish.sangwan2@gmail.com>
Signed-off-by: NJan Kara <jack@suse.cz>

In case we detect a problem and bail out, we fail to set "ret" to a
nonzero value, and udf_load_logicalvol will mistakenly report success.
Signed-off-by: NNikola Pajkovsky <npajkovs@redhat.com>
Signed-off-by: NJan Kara <jack@suse.cz>

If s_lvid_bh is not freed and set to NULL before re-scanning partition
with default block size, we might end up using wrong lvid in case
s_lvid_bh is not updated in udf_load_logicalvolint during rescan.
Signed-off-by: NAshish Sangwan <ashish.sangwan2@gmail.com>
Signed-off-by: NNamjae Jeon <linkinjeon@gmail.com>
Signed-off-by: NJan Kara <jack@suse.cz>

If the new size is larger than the old size and the old file data was
stored in the ICB (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) and the
new size still fits in the ICB, skip the call to udf_extend_file() as it
does not handle this i_alloc_type value (it calls BUG()).
Signed-off-by: NIan Abbott <abbotti@mev.co.uk>
Signed-off-by: NJan Kara <jack@suse.cz>

boolean "does it have to be exclusive?" flag is passed instead;
Local filesystem should just ignore it - the object is guaranteed
not to be there yet.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument.  And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

For type 0x51 the udf.parent_partref member in struct fid gets copied
uninitialized to userland. Fix this by initializing it to 0.
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Signed-off-by: NJan Kara <jack@suse.cz>

When a partition table length is corrupted to be close to 1 << 32, the
check for its length may overflow on 32-bit systems and we will think
the length is valid. Later on the kernel can crash trying to read beyond
end of buffer. Fix the check to avoid possible overflow.

CC: stable@vger.kernel.org
Reported-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NJan Kara <jack@suse.cz>

Indirect extent block is not accounted in i_blocks during allocation
thus we should not decrement i_blocks when we are freeing such block
during truncation.
Reported-by: NSteve Nickel <snickel58@gmail.com>
Signed-off-by: NJan Kara <jack@suse.cz>

When we are mounting filesystem, we can load one partition table before
finding out that we cannot complete processing of logical volume descriptor
and trying the reserve descriptor. Free the table properly before trying
the reserve descriptor.
Signed-off-by: NJan Kara <jack@suse.cz>

The variable "offset" is not needed. Remove it.
Signed-off-by: NAshish Sangwan <ashish.sangwan2@gmail.com>
Signed-off-by: NNamjae Jeon <linkinjeon@gmail.com>
Signed-off-by: NJan Kara <jack@suse.cz>