Currently all quota block reservation macros contains hard-coded "2"
aka MAXQUOTAS value. This is no good because in some places it is not
obvious to understand what does this digit represent. Let's introduce
new macro with self descriptive name.
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Acked-by: NMingming Cao <cmm@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Acked-by: NMingming Cao <cmm@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This fixes a leak of blocks in an inode prealloc list if device failures
cause ext4_mb_mark_diskspace_used() to fail.
Signed-off-by: NCurt Wohlgemuth <curtw@google.com>
Acked-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

There is a potential race when a transaction is committing right when
the file system is being umounting.  This could reduce in a race
because EXT4_SB(sb)->s_group_info could be freed in ext4_put_super
before the commit code calls a callback so the mballoc code can
release freed blocks in the transaction, resulting in a panic trying
to access the freed s_group_info.

The fix is to wait for the transaction to finish committing before we
shutdown the multiblock allocator.  
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

When ext4_write_begin fails after allocating some blocks or
generic_perform_write fails to copy data to write, we truncate blocks
already instantiated beyond i_size.  Although these blocks were never
inside i_size, we have to truncate the pagecache of these blocks so
that corresponding buffers get unmapped.  Otherwise subsequent
__block_prepare_write (called because we are retrying the write) will
find the buffers mapped, not call ->get_block, and thus the page will
be backed by already freed blocks leading to filesystem and data
corruption.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Add a new config option, CONFIG_EXT4_USE_FOR_EXT23 which if enabled,
will cause ext4 to be used for either ext2 or ext3 file system mounts
when ext2 or ext3 is not enabled in the configuration.

This allows minimalist kernel fanatics to drop to file system drivers
from their compiled kernel with out losing functionality.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

CC: Jan Kara <jack@suse.cz> 
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Integrate duplicate lines (acquire/release semaphore and invalidate
extent cache in move_extent_per_page()) into mext_replace_branches(),
to reduce source and object code size.
Signed-off-by: NAkira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The move_extent.moved_len is used to pass back the number of exchanged
blocks count to user space.  Currently the caller must clear this
field; but we spend more code space checking for this requirement than
simply zeroing the field ourselves, so let's just make life easier for
everyone all around.
Signed-off-by: NKazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: NAkira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

At the beginning of ext4_move_extent(), we call
ext4_discard_preallocations() to discard inode PAs of orig and donor
inodes.  But in the following case, blocks can be double freed, so
move ext4_discard_preallocations() to the end of ext4_move_extents().

1. Discard inode PAs of orig and donor inodes with
   ext4_discard_preallocations() in ext4_move_extents().

   orig : [ DATA1 ]
   donor: [ DATA2 ]

2. While data blocks are exchanging between orig and donor inodes, new
   inode PAs is created to orig by other process's block allocation.
   (Since there are semaphore gaps in ext4_move_extents().)  And new
   inode PAs is used partially (2-1).

   2-1 Create new inode PAs to orig inode
   orig : [ DATA1 | used PA1 | free PA1 ]
   donor: [ DATA2 ]

3. Donor inode which has old orig inode's blocks is deleted after
   EXT4_IOC_MOVE_EXT finished (3-1, 3-2).  So the block bitmap
   corresponds to old orig inode's blocks are freed.

   3-1 After EXT4_IOC_MOVE_EXT finished
   orig : [ DATA2 |  free PA1 ]
   donor: [ DATA1 |  used PA1 ]

   3-2 Delete donor inode
   orig : [ DATA2 |  free PA1 ]
   donor: [ FREE SPACE(DATA1) | FREE SPACE(used PA1) ]

4. The double-free of blocks is occurred, when close() is called to
   orig inode.  Because ext4_discard_preallocations() for orig inode
   frees used PA1 and free PA1, though used PA1 is already freed in 3.

   4-1 Double-free of blocks is occurred
   orig : [ DATA2 |  FREE SPACE(free PA1) ]
   donor: [ FREE SPACE(DATA1) | DOUBLE FREE(used PA1) ]
Signed-off-by: NAkira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The block validity framework does a more comprehensive set of checks,
and it saves object code space to use the ext4_data_block_valid() than
the limited open-coded version that had been in ext4_free_blocks().
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

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

Add the facility for ext4_forget() to be called from
ext4_free_blocks().  This simplifies the code in a large number of
places, and centralizes most of the work of calling ext4_forget() into
a single place.

Also fix a bug in the extents migration code; it wasn't calling
ext4_forget() when releasing the indirect blocks during the
conversion.  As a result, if the system cashed during or shortly after
the extents migration, and the released indirect blocks get reused as
data blocks, the journal replay would corrupt the data blocks.  With
this new patch, fixing this bug was as simple as adding the
EXT4_FREE_BLOCKS_FORGET flags to the call to ext4_free_blocks().
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

ext4_mb_free_blocks() is only called by ext4_free_blocks(), and the
latter function doesn't really do much.  So merge the two functions
together, such that ext4_free_blocks() is now found in
fs/ext4/mballoc.c.  This saves about 200 bytes of compiled text space.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Convert the last two callers of ext4_journal_forget() to use
ext4_forget() instead, and then fold ext4_journal_forget() into
ext4_forget().  This reduces are code complexity and shortens our call
stack.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The only caller of ext4_journal_revoke() is ext4_forget(), so we can
fold ext4_journal_revoke() into ext4_forget() to simplify the code and
shorten the call stack.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The ext4_forget() function better belongs in ext4_jbd2.c.  This will
allow us to do some cleanup of the ext4_journal_revoke() and
ext4_journal_forget() functions, as well as giving us better error
reporting since we can report the caller of ext4_forget() when things
go wrong.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Users on the linux-ext4 list recently complained about differences
across filesystems w.r.t. how to mount without a journal replay.

In the discussion it was noted that xfs's "norecovery" option is
perhaps more descriptively accurate than "noload," so let's make
that an alias for ext4.

Also show this status in /proc/mounts
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

It is anticipated that when sb_issue_discard starts doing
real work on trim-capable devices, we may see issues.  Make
this mount-time optional, and default it to off until we know
that things are working out OK.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

When an error happened in ext4_splice_branch we failed to notice that
in ext4_ind_get_blocks and mapped the buffer anyway. Fix the problem
by checking for error properly.
Signed-off-by: NJan Kara <jack@suse.cz>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org	       

We don't to issue an I/O barrier on an error or if we force commit
because we are doing data journaling.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org

The block validity checks used by ext4_data_block_valid() wasn't
correctly written to check file systems with the meta_bg feature.  Fix
this.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

The number of old-style block group descriptor blocks is
s_meta_first_bg when the meta_bg feature flag is set.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

commit a71ce8c6 updated ext4_statfs()
to update the on-disk superblock counters, but modified this buffer
directly without any journaling of the change.  This is one of the
accesses that was causing the crc errors in journal replay as seen in
kernel.org bugzilla #14354.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

ext4_xattr_set_handle() was zeroing out an inode outside
of journaling constraints; this is one of the accesses that
was causing the crc errors in journal replay as seen in
kernel.org bugzilla #14354.
Reviewed-by: NAndreas Dilger <adilger@sun.com>
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

We need to be testing the i_flags field in the ext4 specific portion
of the inode, instead of the (confusingly aliased) i_flags field in
the generic struct inode.
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

When an inode gets unlinked, the functions ext4_clear_blocks() and
ext4_remove_blocks() call ext4_forget() for all the buffer heads
corresponding to the deleted inode's data blocks.  If the inode is a
directory or a symlink, the is_metadata parameter must be non-zero so
ext4_forget() will revoke them via jbd2_journal_revoke().  Otherwise,
if these blocks are reused for a data file, and the system crashes
before a journal checkpoint, the journal replay could end up
corrupting these data blocks.

Thanks to Curt Wohlgemuth for pointing out potential problems in this
area.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

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

Now that we are checking for failed journal checksums in the jbd2
layer, we don't need to check in the ext4 mount path --- since a
checksum fail will result in ext4_load_journal() returning an error,
causing the file system to refuse to be mounted until e2fsck can deal
with the problem.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

One of the invalid error paths in ext4_iget() forgot to brelse() the
inode buffer head.  Fix it by adding a brelse() in the common error
return path, which also simplifies function.

Thanks to Andi Kleen <ak@linux.intel.com> reporting the problem.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Fix a few spelling typos in move_extent.c
Signed-off-by: NAkira Fujita <a-fujita@rs.jp.nec.co.jp>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

If CONFIG_PROVE_LOCKING is enabled, the double_down_write_data_sem()
will trigger a false-positive warning of a recursive lock.  Since we
take i_data_sem for the two inodes ordered by their inode numbers,
this isn't a problem.  Use of down_write_nested() will notify the lock
dependency checker machinery that there is no problem here.

This problem was reported by Brian Rogers:

	http://marc.info/?l=linux-ext4&m=125115356928011&w=1Reported-by: NBrian Rogers <brian@xyzw.org>
Signed-off-by: NAkira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

ext4_move_extents() checks the logical block contiguousness
of original file with ext4_find_extent() and mext_next_extent().
Therefore the extent which ext4_ext_path structure indicates
must not be changed between above functions.

But in current implementation, there is no i_data_sem protection
between ext4_ext_find_extent() and mext_next_extent().  So the extent
which ext4_ext_path structure indicates may be overwritten by
delalloc.  As a result, ext4_move_extents() will exchange wrong blocks
between original and donor files.  I change the place where
acquire/release i_data_sem to solve this problem.

Moreover, I changed move_extent_per_page() to start transaction first,
and then acquire i_data_sem.  Without this change, there is a
possibility of the deadlock between mmap() and ext4_move_extents():

* NOTE: "A", "B" and "C" mean different processes

A-1: ext4_ext_move_extents() acquires i_data_sem of two inodes.

B:   do_page_fault() starts the transaction (T),
     and then tries to acquire i_data_sem.
     But process "A" is already holding it, so it is kept waiting.

C:   While "A" and "B" running, kjournald2 tries to commit transaction (T)
     but it is under updating, so kjournald2 waits for it.

A-2: Call ext4_journal_start with holding i_data_sem,
     but transaction (T) is locked.
Signed-off-by: NAkira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

If the EXT4_IOC_MOVE_EXT ioctl fails, the number of blocks that were
exchanged before the failure should be returned to the userspace
caller.  Unfortunately, currently if the block size is not the same as
the page size, the returned block count that is returned is the
page-aligned block count instead of the actual block count.  This
commit addresses this bug.
Signed-off-by: NAkira Fujita <a-fujita@rs.jp.nec.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

If s_log_groups_per_flex is greater than 31, then groups_per_flex will
will overflow and cause a divide by zero error.  This can cause kernel
BUG if such a file system is mounted.

Thanks to Nageswara R Sastry for analyzing the failure and providing
an initial patch.

http://bugzilla.kernel.org/show_bug.cgi?id=14287Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org

Previously add_dirent_to_buf() did not free its passed-in buffer head
in the case of ENOSPC, since in some cases the caller still needed it.
However, this led to potential buffer head leaks since not all callers
dealt with this correctly.  Fix this by making simplifying the freeing
convention; now add_dirent_to_buf() *never* frees the passed-in buffer
head, and leaves that to the responsibility of its caller.  This makes
things cleaner and easier to prove that the code is neither leaking
buffer heads or calling brelse() one time too many.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: Curt Wohlgemuth <curtw@google.com>
Cc: stable@kernel.org

This is a partial revert of commit 6487a9d3 (only the changes made to
fs/ext4/namei.c), since it is causing the following brelse()
double-free warning when running fsstress on a file system with 1k
blocksize and we run into a block allocation failure while converting
a single-block directory to a multi-block hash-tree indexed directory.

WARNING: at fs/buffer.c:1197 __brelse+0x2e/0x33()
Hardware name: 
VFS: brelse: Trying to free free buffer
Modules linked in:
Pid: 2226, comm: jbd2/sdd-8 Not tainted 2.6.32-rc6-00577-g0003f55 #101
Call Trace:
 [<c01587fb>] warn_slowpath_common+0x65/0x95
 [<c0158869>] warn_slowpath_fmt+0x29/0x2c
 [<c021168e>] __brelse+0x2e/0x33
 [<c0288a9f>] jbd2_journal_refile_buffer+0x67/0x6c
 [<c028a9ed>] jbd2_journal_commit_transaction+0x319/0x14d8
 [<c0164d73>] ? try_to_del_timer_sync+0x58/0x60
 [<c0175bcc>] ? sched_clock_cpu+0x12a/0x13e
 [<c017f6b4>] ? trace_hardirqs_off+0xb/0xd
 [<c0175c1f>] ? cpu_clock+0x3f/0x5b
 [<c017f6ec>] ? lock_release_holdtime+0x36/0x137
 [<c0664ad0>] ? _spin_unlock_irqrestore+0x44/0x51
 [<c0180af3>] ? trace_hardirqs_on_caller+0x103/0x124
 [<c0180b1f>] ? trace_hardirqs_on+0xb/0xd
 [<c0164d73>] ? try_to_del_timer_sync+0x58/0x60
 [<c0290d1c>] kjournald2+0x11a/0x310
 [<c017118e>] ? autoremove_wake_function+0x0/0x38
 [<c0290c02>] ? kjournald2+0x0/0x310
 [<c0170ee6>] kthread+0x66/0x6b
 [<c0170e80>] ? kthread+0x0/0x6b
 [<c01251b3>] kernel_thread_helper+0x7/0x10
---[ end trace 5579351b86af61e3 ]---

Commit 6487a9d3 was an attempt some buffer head leaks in an ENOSPC
error path, but in some cases it actually results in an excess ENOSPC,
as shown above.  Fixing this means cleaning up who is responsible for
releasing the buffer heads from the callee to the caller of
add_dirent_to_buf().

Since that's a relatively complex change, and we're late in the rcX
development cycle, I'm reverting this now, and holding back a more
complete fix until after 2.6.32 ships.  We've lived with this
buffer_head leak on ENOSPC in ext3 and ext4 for a very long time; a
few more months won't kill us.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: Curt Wohlgemuth <curtw@google.com>

To prepare for a direct I/O write, we need to split the unwritten
extents before submitting the I/O.  When no extents needed to be
split, ext4_split_unwritten_extents() was incorrectly returning 0
instead of the size of uninitialized extents. This bug caused the
wrong return value sent back to VFS code when it gets called from
async IO path, leading to an unnecessary fall back to buffered IO.

This bug also hid the fact that the check to see whether or not a
split would be necessary was incorrect; we can only skip splitting the
extent if the write completely covers the uninitialized extent.
Signed-off-by: NMingming Cao <cmm@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The ext4_debug() call in ext4_end_io_dio() should be moved after the
check to make sure that io_end is non-NULL.

The comment above ext4_get_block_dio_write() ("Maximum number of
blocks...") is a duplicate; the original and correct comment is above
the #define DIO_MAX_BLOCKS up above.

Based on review comments from Curt Wohlgemuth.
Signed-off-by: NMingming Cao <cmm@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>