fs: move inode_dio_wait calls into ->setattr

Let filesystems handle waiting for direct I/O requests themselves instead
of doing it beforehand.  This means filesystem-specific locks to prevent
new dio referenes from appearing can be held.  This is important to allow
generalizing i_dio_count to non-DIO_LOCKING filesystems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
ext3: Fix data corruption in inodes with journalled data

When journalling data for an inode (either because it is a symlink or
because the filesystem is mounted in data=journal mode), ext3_evict_inode()
can discard unwritten data by calling truncate_inode_pages(). This is
because we don't mark the buffer / page dirty when journalling data but only
add the buffer to the running transaction and thus mm does not know there
are still unwritten data.

Fix the problem by carefully tracking transaction containing inode's data,
committing this transaction, and writing uncheckpointed buffers when inode
should be reaped.

Signed-off-by: Jan Kara <jack@suse.cz>
ext3: NULL dereference in ext3_evict_inode()

This is an fsfuzzer bug.  ->s_journal is set at the end of
ext3_load_journal() but we try to use it in the error handling from
ext3_get_journal() while it's still NULL.

[  337.039041] BUG: unable to handle kernel NULL pointer dereference at 0000000000000024
[  337.040380] IP: [<ffffffff816e6539>] _raw_spin_lock+0x9/0x30
[  337.041687] PGD 0
[  337.043118] Oops: 0002 [#1] SMP
[  337.044483] CPU 3
[  337.044495] Modules linked in: ecb md4 cifs fuse kvm_intel kvm brcmsmac brcmutil crc8 cordic r8169 [last unloaded: scsi_wait_scan]
[  337.047633]
[  337.049259] Pid: 8308, comm: mount Not tainted 3.2.0-rc2-next-20111121+ #24 SAMSUNG ELECTRONICS CO., LTD. RV411/RV511/E3511/S3511    /RV411/RV511/E3511/S3511
[  337.051064] RIP: 0010:[<ffffffff816e6539>]  [<ffffffff816e6539>] _raw_spin_lock+0x9/0x30
[  337.052879] RSP: 0018:ffff8800b1d11ae8  EFLAGS: 00010282
[  337.054668] RAX: 0000000000000100 RBX: 0000000000000000 RCX: ffff8800b77c2000
[  337.056400] RDX: ffff8800a97b5c00 RSI: 0000000000000000 RDI: 0000000000000024
[  337.058099] RBP: ffff8800b1d11ae8 R08: 6000000000000000 R09: e018000000000000
[  337.059841] R10: ff67366cc2607c03 R11: 00000000110688e6 R12: 0000000000000000
[  337.061607] R13: 0000000000000000 R14: 0000000000000000 R15: ffff8800a78f06e8
[  337.063385] FS:  00007f9d95652800(0000) GS:ffff8800b7180000(0000) knlGS:0000000000000000
[  337.065110] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  337.066801] CR2: 0000000000000024 CR3: 00000000aef2c000 CR4: 00000000000006e0
[  337.068581] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  337.070321] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  337.072105] Process mount (pid: 8308, threadinfo ffff8800b1d10000, task ffff8800b1d02be0)
[  337.073800] Stack:
[  337.075487]  ffff8800b1d11b08 ffffffff811f48cf ffff88007ac9b158 0000000000000000
[  337.077255]  ffff8800b1d11b38 ffffffff8119405d ffff88007ac9b158 ffff88007ac9b250
[  337.078851]  ffffffff8181bda0 ffffffff8181bda0 ffff8800b1d11b68 ffffffff81131e31
[  337.080284] Call Trace:
[  337.081706]  [<ffffffff811f48cf>] log_start_commit+0x1f/0x40
[  337.083107]  [<ffffffff8119405d>] ext3_evict_inode+0x1fd/0x2a0
[  337.084490]  [<ffffffff81131e31>] evict+0xa1/0x1a0
[  337.085857]  [<ffffffff81132031>] iput+0x101/0x210
[  337.087220]  [<ffffffff811339d1>] iget_failed+0x21/0x30
[  337.088581]  [<ffffffff811905fc>] ext3_iget+0x15c/0x450
[  337.089936]  [<ffffffff8118b0c1>] ? ext3_rsv_window_add+0x81/0x100
[  337.091284]  [<ffffffff816df9a4>] ext3_get_journal+0x15/0xde
[  337.092641]  [<ffffffff811a2e9b>] ext3_fill_super+0xf2b/0x1c30
[  337.093991]  [<ffffffff810ddf7d>] ? register_shrinker+0x4d/0x60
[  337.095332]  [<ffffffff8111c112>] mount_bdev+0x1a2/0x1e0
[  337.096680]  [<ffffffff811a1f70>] ? ext3_setup_super+0x210/0x210
[  337.098026]  [<ffffffff8119a770>] ext3_mount+0x10/0x20
[  337.099362]  [<ffffffff8111cbee>] mount_fs+0x3e/0x1b0
[  337.100759]  [<ffffffff810eda1b>] ? __alloc_percpu+0xb/0x10
[  337.102330]  [<ffffffff81135385>] vfs_kern_mount+0x65/0xc0
[  337.103889]  [<ffffffff8113611f>] do_kern_mount+0x4f/0x100
[  337.105442]  [<ffffffff811378fc>] do_mount+0x19c/0x890
[  337.106989]  [<ffffffff810e8456>] ? memdup_user+0x46/0x90
[  337.108572]  [<ffffffff810e84f3>] ? strndup_user+0x53/0x70
[  337.110114]  [<ffffffff811383fb>] sys_mount+0x8b/0xe0
[  337.111617]  [<ffffffff816ed93b>] system_call_fastpath+0x16/0x1b
[  337.113133] Code: 38 c2 74 0f 66 0f 1f 44 00 00 f3 90 0f b6 03 38 c2 75 f7 48 83 c4 08 5b 5d c3 0f 1f 84 00 00 00 00 00 55 b8 00 01 00 00 48 89 e5 <f0> 66 0f c1 07 0f b6 d4 38 c2 74 0c 0f 1f 00 f3 90 0f b6 07 38
[  337.116588] RIP  [<ffffffff816e6539>] _raw_spin_lock+0x9/0x30
[  337.118260]  RSP <ffff8800b1d11ae8>
[  337.119998] CR2: 0000000000000024
[  337.188701] ---[ end trace c36d790becac1615 ]---

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>
ext3: replace ll_rw_block with other functions

ll_rw_block() is deprecated. Thus we replace it with other functions.

CC: Jan Kara <jack@suse.cz>
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: Jan Kara <jack@suse.cz>
ext3: add support for .read_iter and .write_iter

From: Zach Brown <zab@zabbo.net>

ext3 uses the generic .read_iter and .write_iter functions.

ext3_direct_IO() is refactored in to helpers which are called by the
.direct_IO{,bvec}() methods which call __blockdev_direct_IO{,_bvec}().
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: Zach Brown <zab@zabbo.net>
Cc: Jan Kara <jack@suse.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
modified by faux123 for Linux 3.0.x
ext4: split ext4_ind_truncate from ext4_truncate

We are about to move all indirect inode functions to a new file.
Before we do that, let's split ext4_ind_truncate() out of ext4_truncate()
leaving only generic code in the latter, so we will be able to move
ext4_ind_truncate() to the new file.

Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: rename ext4_indirect_* funcs to ext4_ind_*

We are going to move all ext4_ind_* functions to indirect.c.
Before we do that, let's rename 2 functions called ext4_indirect_*
to ext4_ind_*, to keep to the naming convention.

Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: move __ext4_check_blockref to block_validity.c

In preparation for moving the indirect functions to a separate file,
move __ext4_check_blockref() to block_validity.c and rename it to
ext4_check_blockref() which is exported as globally visible function.

Also, rename the cpp macro ext4_check_inode_blockref() to
ext4_ind_check_inode(), to make it clear that it is only valid for use
with non-extent mapped inodes.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: move common truncate functions to header file

Move two functions that will be needed by the indirect functions to be
moved to indirect.c as well as inode.c to truncate.h as inline
functions, so that we can avoid having duplicate copies of the
function (which can be a maintenance problem) without having to expose
them as globally functions.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: move ext4_ind_* functions from inode.c to indirect.c

This patch moves functions from inode.c to indirect.c.
The moved functions are ext4_ind_* functions and their helpers.
Functions called from inode.c are declared extern.

Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
modified by faux123 for Linux 3.0.x

Conflicts:
	fs/ext4/inode.c
ext4: refactor duplicated block placement code

I found that ext4_ext_find_goal() and ext4_find_near()
share the same code for returning a coloured start block
based on i_block_group.

We can refactor this into a common function so that they
don't diverge in the future.

Thanks to adilger for suggesting the new function name.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: quiet 'unused variables' compile warnings

Unused variables was deleted.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: remove loop around bio_alloc()

These days, bio_alloc() is guaranteed to never fail (as long as nvecs
is less than BIO_MAX_PAGES), so we don't need the loop around the
struct bio allocation.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: flush any pending end_io requests before DIO reads
 w/dioread_nolock

There is a race between ext4 buffer write and direct_IO read with
dioread_nolock mount option enabled. The problem is that we clear
PageWriteback flag during end_io time but will do
uninitialized-to-initialized extent conversion later with dioread_nolock.
If an O_direct read request comes in during this period, ext4 will return
zero instead of the recently written data.

This patch checks whether there are any pending uninitialized-to-initialized
extent conversion requests before doing O_direct read to close the race.
Note that this is just a bandaid fix. The fundamental issue is that we
clear PageWriteback flag before we really complete an IO, which is
problem-prone. To fix the fundamental issue, we may need to implement an
extent tree cache that we can use to look up pending to-be-converted extents.

Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
modified by faux123
ext4: fix fsx truncate failure

While running extended fsx tests to verify the first
two patches, a similar bug was also found in the
truncate operation.

This bug happens because the truncate routine only zeros
the unblock aligned portion of the last page.  This means
that the block aligned portions of the page appearing after
i_size are left unzeroed, and the buffer heads still mapped.

This bug is corrected by using ext4_discard_partial_page_buffers
in the truncate routine to zero the partial page and unmap
the buffer headers.

Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: enforce bigalloc restrictions (e.g., no online resizing, etc.)

At least initially if the bigalloc feature is enabled, we will not
support non-extent mapped inodes, online resizing, online defrag, or
the FITRIM ioctl.  This simplifies the initial implementation.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: add ext4-specific kludge to avoid an oops after the disk disappears

The del_gendisk() function uninitializes the disk-specific data
structures, including the bdi structure, without telling anyone
else.  Once this happens, any attempt to call mark_buffer_dirty()
(for example, by ext4_commit_super), will cause a kernel OOPS.

Fix this for now until we can fix things in an architecturally correct
way.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: read-only support for bigalloc file systems

This adds supports for bigalloc file systems.  It teaches the mount
code just enough about bigalloc superblock fields that it will mount
the file system without freaking out that the number of blocks per
group is too big.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: convert instances of EXT4_BLOCKS_PER_GROUP to EXT4_CLUSTERS_PER_GROUP

Change the places in fs/ext4/mballoc.c where EXT4_BLOCKS_PER_GROUP are
used to indicate the number of bits in a block bitmap (which is really
a cluster allocation bitmap in bigalloc file systems).  There are
still some places in the ext4 codebase where usage of
EXT4_BLOCKS_PER_GROUP needs to be audited/fixed, in code paths that
aren't used given the initial restricted assumptions for bigalloc.
These will need to be fixed before we can relax those restrictions.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
ext4: factor out block group accounting into functions

This makes it easier to understand how ext4_init_block_bitmap() works,
and it will assist when we split out ext4_free_blocks_after_init() in
the next commit.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>