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>

At the end of direct I/O operation, ext4_ext_direct_IO() always called
ext4_convert_unwritten_extents(), regardless of whether there were any
unwritten extents involved in the I/O or not.

This commit adds a state flag so that ext4_ext_direct_IO() only calls
ext4_convert_unwritten_extents() when necessary.
Signed-off-by: NMingming Cao <cmm@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

After a direct I/O request covering an uninitalized extent (i.e.,
created using the fallocate system call) or a hole in a file, ext4
will convert the uninitialized extent so it is marked as initialized
by calling ext4_convert_unwritten_extents().  This function returns
zero on success.

This return value was getting returned by ext4_direct_IO(); however
the file system's direct_IO function is supposed to return the number
of bytes read or written on a success.  By returning zero, it confused
the direct I/O code into falling back to buffered I/O unnecessarily.
Signed-off-by: NMingming Cao <cmm@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

When restart a transaction during a truncate operation, we drop and
reacquire i_data_sem.  After reacquiring i_data_sem, we need to
discard any inode-based preallocation that might have been grabbed
while we released i_data_sem (for example, if pdflush is allocating
blocks and racing against the truncate).
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This reverts commit d0646f7b, as
requested by Eric Sandeen.

It can basically cause an ext4 filesystem to miss recovery (and thus get
mounted with errors) if the journal checksum does not match.

Quoth Eric:

   "My hand-wavy hunch about what is happening is that we're finding a
    bad checksum on the last partially-written transaction, which is
    not surprising, but if we have a wrapped log and we're doing the
    initial scan for head/tail, and we abort scanning on that bad
    checksum, then we are essentially running an unrecovered filesystem.

    But that's hand-wavy and I need to go look at the code.

    We lived without journal checksums on by default until now, and at
    this point they're doing more harm than good, so we should revert
    the default-changing commit until we can fix it and do some good
    power-fail testing with the fixes in place."

See

	http://bugzilla.kernel.org/show_bug.cgi?id=14354

for all the gory details.
Requested-by: NEric Sandeen <sandeen@redhat.com>
Cc: Theodore Tso <tytso@mit.edu>
Cc: Alexey Fisher <bug-track@fisher-privat.net>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Mathias Burén <mathias.buren@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On a 256M filesystem, doing this in a loop:

        xfs_io -F -f -d -c 'pwrite 0 64m' test
        rm -f test

eventually leads to ENOSPC.  (the xfs_io command does a
64m direct IO write to the file "test")

As with other block allocation callers, it looks like we need to
potentially retry the allocations on the initial ENOSPC.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This fixes the following warning:

fs/ext4/inode.c: In function 'ext4_dirty_inode':
fs/ext4/inode.c:5615: warning: unused variable 'current_handle'

We remove the jbd_debug() statement which does use current_handle, as
it's not terribly important in the grand scheme of things.

Thanks to Stephen Rothwell for pointing this out.
Signed-off-by: NCurt Wohlgemuth <curtw@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Kconfig & super.c promised it'd be gone by 2.6.31, so it's
about time to drop it.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

In ext4_num_dirty_pages() we were calling page_buffers() before
checking to see if the page actually had pages attached to it; this
would cause a BUG check crash in the inline function page_buffers().

Thanks to Markus Trippelsdorf for reporting this bug.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

"Looking at ext4.h, I think the setting of extra time fields forgets to
mask the epoch bits so the epoch part overwrites nsec part. The second
change is only for coherency (2 -> EXT4_EPOCH_BITS)."

Thanks to Damien Guibouret for pointing out this problem.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The /proc/fs/ext4/<dev>/mb_history was maintained manually, and had a
number of problems: it required a largish amount of memory to be
allocated for each ext4 filesystem, and the s_mb_history_lock
introduced a CPU contention problem.  

By ripping out the mb_history code and replacing it with ftrace
tracepoints, and we get more functionality: timestamps, event
filtering, the ability to correlate mballoc history with other ext4
tracepoints, etc.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

There are a number of kernel printk's which are printed when an ext4
filesystem is mounted and unmounted.  Disable them to economize space
in the system logs.  In addition, disabling the mballoc stats by
default saves a number of unneeded atomic operations for every block
allocation or deallocation.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This patch fixes a problem with handling nested calls to
ext4_journal_start/ext4_journal_stop, when there is no journal present.
Signed-off-by: NCurt Wohlgemuth <curtw@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This patch a problem that ext4_dirty_inode() was not calling
ext4_mark_inode_dirty() if the current_handle is not valid, which it
is the case in no journal mode.

It also removes a test for non-matching transaction which can never
happen.
Signed-off-by: NCurt Wohlgemuth <curtw@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This is a cleanup of commit 91ac6f43.  Since ext4_mark_inode_dirty()
has already called ext4_mark_iloc_dirty(), which in turn calls
ext4_do_update_inode(), it's not necessary to have ext4_write_inode()
call ext4_do_update_inode() in no journal mode.  Indeed, it would be
duplicated work.
Reviewed-by: N"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NFrank Mayhar <fmayhar@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>