Currently we are not marking the extent as the last one
(FIEMAP_EXTENT_LAST) if there is a hole at the end of the file. This is
because we just do not check for it right now and continue searching for
next extent. But at the point we hit the hole at the end of the file, it
is too late.

This commit adds check for the allocated block in subsequent extent and
if there is no more extents (block = EXT_MAX_BLOCKS) just flag the
current one as the last one.

This behaviour has been spotted unintentionally by 252 xfstest, when the
test hangs out, because of wrong loop condition. However on other
filesystems (like xfs) it will exit anyway, because we notice the last
extent flag and exit.

With this patch xfstest 252 does not hang anymore, ext4 fiemap
implementation still reports bad extent type in some cases, however
this seems to be different issue.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Kazuya Mio reported that he was able to hit BUG_ON(next == lblock)
in ext4_ext_put_gap_in_cache() while creating a sparse file in extent
format and fill the tail of file up to its end. We will hit the BUG_ON
when we write the last block (2^32-1) into the sparse file.

The root cause of the problem lies in the fact that we specifically set
s_maxbytes so that block at s_maxbytes fit into on-disk extent format,
which is 32 bit long. However, we are not storing start and end block
number, but rather start block number and length in blocks. It means
that in order to cover extent from 0 to EXT_MAX_BLOCK we need
EXT_MAX_BLOCK+1 to fit into len (because we counting block 0 as well) -
and it does not.

The only way to fix it without changing the meaning of the struct
ext4_extent members is, as Kazuya Mio suggested, to lower s_maxbytes
by one fs block so we can cover the whole extent we can get by the
on-disk extent format.

Also in many places EXT_MAX_BLOCK is used as length instead of maximum
logical block number as the name suggests, it is all a bit messy. So
this commit renames it to EXT_MAX_BLOCKS and change its usage in some
places to actually be maximum number of blocks in the extent.

The bug which this commit fixes can be reproduced as follows:

 dd if=/dev/zero of=/mnt/mp1/file bs=<blocksize> count=1 seek=$((2**32-2))
 sync
 dd if=/dev/zero of=/mnt/mp1/file bs=<blocksize> count=1 seek=$((2**32-1))
Reported-by: NKazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Make ext4_ext_split() get extents to be moved by calculating in a statement
instead of counting in a loop.
Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Currently, an fallocate request of size slightly larger than a power of
2 is turned into two block requests, each a power of 2, with the extra
blocks pre-allocated for future use. When an application calls
fallocate, it already has an idea about how large the file may grow so
there is usually little benefit to reserve extra blocks on the
preallocation list. This reduces disk fragmentation.

Tested: fsstress. Also verified manually that fallocat'ed files are
contiguously laid out with this change (whereas without it they begin at
power-of-2 boundaries, leaving blocks in between). CPU usage of
fallocate is not appreciably higher.  In a tight fallocate loop, CPU
usage hovers between 5%-8% with this change, and 5%-7% without it.

Using a simulated file system aging program which the file system to
70%, the percentage of free extents larger than 8MB (as measured by
e2freefrag) increased from 38.8% without this change, to 69.4% with
this change.
Signed-off-by: NVivek Haldar <haldar@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This patch adds new routines: "ext4_punch_hole" "ext4_ext_punch_hole"
and "ext4_ext_check_cache"

fallocate has been modified to call ext4_punch_hole when the punch hole
flag is passed.  At the moment, we only support punching holes in
extents, so this routine is pretty much a wrapper for the ext4_ext_punch_hole
routine.

The ext4_ext_punch_hole routine first completes all outstanding writes
with the associated pages, and then releases them.  The unblock
aligned data is zeroed, and all blocks in between are punched out.

The ext4_ext_check_cache routine is very similar to ext4_ext_in_cache
except it accepts a ext4_ext_cache parameter instead of a ext4_extent
parameter.  This routine is used by ext4_ext_punch_hole to check and
see if a block in a hole that has been cached.  The ext4_ext_cache
parameter is necessary because the members ext4_extent structure are
not large enough to hold a 32 bit value.  The existing
ext4_ext_in_cache routine has become a wrapper to this new function.

[ext4 punch hole patch series 5/5 v7] 
Signed-off-by: NAllison Henderson <achender@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NMingming Cao <cmm@us.ibm.com>

This patch adds a new flag to ext4_map_blocks() that specifies the
given range of blocks should be punched out.  Extents are first
converted to uninitialized extents before they are punched
out. Because punching a hole may require that the extent be split, it
is possible that the splitting may need more blocks than are
available.  To deal with this, use of reserved blocks are enabled to
allow the split to proceed.

The routine then returns the number of blocks successfully
punched out.

[ext4 punch hole patch series 4/5 v7]
Signed-off-by: NAllison Henderson <achender@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NMingming Cao <cmm@us.ibm.com>

This patch modifies the truncate routines to support hole punching
Below is a brief summary of the patches changes:

- Added end param to ext_ext4_rm_leaf
        This function has been modified to accept an end parameter
        which enables it to punch holes in leafs instead of just
        truncating them.

- Implemented the "remove head" case in the ext_remove_blocks routine
        This routine is used by ext_ext4_rm_leaf to remove the tail
        of an extent during a truncate.  The new ext_ext4_rm_leaf
        routine will now also use it to remove the head of an extent in the
        case that the hole covers a region of blocks at the beginning
        of an extent.

- Added "end" param to ext4_ext_remove_space routine
        This function has been modified to accept a stop parameter, which
        is passed through to ext4_ext_rm_leaf.

[ext4 punch hole patch series 3/5 v6] 
Signed-off-by: NAllison Henderson <achender@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This patch adds an allocation request flag to the ext4_has_free_blocks
function which enables the use of reserved blocks.  This will allow a
punch hole to proceed even if the disk is full.  Punching a hole may
require additional blocks to first split the extents.

Because ext4_has_free_blocks is a low level function, the flag needs
to be passed down through several functions listed below:

ext4_ext_insert_extent
ext4_ext_create_new_leaf
ext4_ext_grow_indepth
ext4_ext_split
ext4_ext_new_meta_block
ext4_mb_new_blocks
ext4_claim_free_blocks
ext4_has_free_blocks

[ext4 punch hole patch series 1/5 v7]
Signed-off-by: NAllison Henderson <achender@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NMingming Cao <cmm@us.ibm.com>

To get delayed-extent information, ext4_ext_fiemap_cb() looks up
pagecache, it thus collects information starting from a page's
head block.

If blocksize < pagesize, the beginning blocks of a page may lies
before the request range. So ext4_ext_fiemap_cb() should proceed
ignoring them, because they has been handled before. If no mapped
buffer in the range is found in the 1st page, we need to look up
the 2nd page, otherwise delayed-extents after a hole will be ignored.

Without this patch, xfstests 225 will hung on ext4 with 1K block.
Reported-by: NAmir Goldstein <amir73il@users.sourceforge.net>
Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

ext4_ext_truncate() should not invoke up_write(&EXT4_I(inode)->i_data_sem)
when ext4_orphan_add() returns an error, as it hasn't performed a
down_write() yet. This trivial patch fixes this by moving the up_write()
invocation above the out_stop label.
Signed-off-by: NEric Gouriou <egouriou@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The number of hits and misses for each filesystem is exposed in
/sys/fs/ext4/<dev>/extent_cache_{hits, misses}.

Tested: fsstress, manual checks.
Signed-off-by: NVivek Haldar <haldar@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NMingming Cao <cmm@us.ibm.com>

This patch addresses bugs found while testing punch hole 
with the fsx test.  The patch corrects the number of blocks
that are zeroed out while splitting an extent, and also corrects
the return value to return the number of blocks split out, instead
of the number of blocks zeroed out.

This patch has been tested in addition to the following patches: 
[Ext4 punch hole v7]
[XFS Tests Punch Hole 1/1 v2] Add Punch Hole Testing to FSX

The test ran successfully for 24 hours.
Signed-off-by: NAllison Henderson <achender@us.ibm.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Reimplement ext4_ext_convert_to_initialized() and
ext4_split_unwritten_extents() using ext4_split_extent()
Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Tested-by: NAllison Henderson <achender@linux.vnet.ibm.com>

Add two functions: ext4_split_extent_at(), which splits an extent into
two extents at given logical block, and ext4_split_extent() which
splits an extent into three extents.
Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Tested-by: NAllison Henderson <achender@linux.vnet.ibm.com>

1) Rename ext4_ext_try_to_merge() to ext4_ext_try_to_merge_right().

2) Add a new function ext4_ext_try_to_merge() which tries to merge
   an extent both left and right.

3) Use the new function in ext4_ext_convert_unwritten_endio() and
   ext4_ext_insert_extent().
Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Tested-by: NAllison Henderson <achender@linux.vnet.ibm.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

ext4 extents cleanup:

  . remove unused `*ex' from check_eofblocks_fl
  . remove unused `*eh' from ext4_ext_map_blocks
Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

- Add more ext4 tracepoints.
- Change ext4 tracepoints to use dev_t field with MAJOR/MINOR macros
so that we can save 4 bytes in the ring buffer on some platforms.
- Add sync_mode to ext4_da_writepages, ext4_da_write_pages, and
ext4_da_writepages_result tracepoints. Also remove for_reclaim
field from ext4_da_writepages since it is usually not very useful.
Signed-off-by: NJiaying Zhang <jiayingz@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Fix the FIEMAP ioctl so that it returns all of the page ranges which
are still subject to delayed allocation.  We were missing some cases
if the file was sparse.

Reported by Chris Mason <chris.mason@oracle.com>:
>We've had reports on btrfs that cp is giving us files full of zeros
>instead of actually copying them.  It was tracked down to a bug with
>the btrfs fiemap implementation where it was returning holes for
>delalloc ranges.
>
>Newer versions of cp are trusting fiemap to tell it where the holes
>are, which does seem like a pretty neat trick.
>
>I decided to give xfs and ext4 a shot with a few tests cases too, xfs
>passed with all the ones btrfs was getting wrong, and ext4 got the basic
>delalloc case right.
>$ mkfs.ext4 /dev/xxx
>$ mount /dev/xxx /mnt
>$ dd if=/dev/zero of=/mnt/foo bs=1M count=1
>$ fiemap-test foo
>ext:   0 logical: [       0..     255] phys:        0..     255
>flags: 0x007 tot: 256
>
>Horray!  But once we throw a hole in, things go bad:
>$ mkfs.ext4 /dev/xxx
>$ mount /dev/xxx /mnt
>$ dd if=/dev/zero of=/mnt/foo bs=1M count=1 seek=1
>$ fiemap-test foo
>< no output >
>
>We've got a delalloc extent after the hole and ext4 fiemap didn't find
>it.  If I run sync to kick the delalloc out:
>$sync
>$ fiemap-test foo
>ext:   0 logical: [     256..     511] phys:    34048..   34303
>flags: 0x001 tot: 256
>
>fiemap-test is sitting in my /usr/local/bin, and I have no idea how it
>got there.  It's full of pretty comments so I know it isn't mine, but
>you can grab it here:
>
>http://oss.oracle.com/~mason/fiemap-test.c
>
>xfsqa has a fiemap program too.

After Fix, test results are as follows:
ext:   0 logical: [     256..     511] phys:        0..     255
flags: 0x007 tot: 256
ext:   0 logical: [     256..     511] phys:    33280..   33535
flags: 0x001 tot: 256

$ mkfs.ext4 /dev/xxx
$ mount /dev/xxx /mnt
$ dd if=/dev/zero of=/mnt/foo bs=1M count=1 seek=1
$ sync
$ dd if=/dev/zero of=/mnt/foo bs=1M count=1 seek=3
$ dd if=/dev/zero of=/mnt/foo bs=1M count=1 seek=5
$ fiemap-test foo
ext:   0 logical: [     256..     511] phys:    33280..   33535
flags: 0x000 tot: 256
ext:   1 logical: [     768..    1023] phys:        0..     255
flags: 0x006 tot: 256
ext:   2 logical: [    1280..    1535] phys:        0..     255
flags: 0x007 tot: 256
Tested-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NAndreas Dilger <adilger@dilger.ca>
Signed-off-by: NYongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This patch fixes the warning "Using plain integer as NULL pointer",
generated by sparse, by replacing the offending 0s with NULL.
Signed-off-by: NPeter Huewe <peterhuewe@gmx.de>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Reviewed-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

ext4 has a data corruption case when doing non-block-aligned
asynchronous direct IO into a sparse file, as demonstrated
by xfstest 240.

The root cause is that while ext4 preallocates space in the
hole, mappings of that space still look "new" and 
dio_zero_block() will zero out the unwritten portions.  When
more than one AIO thread is going, they both find this "new"
block and race to zero out their portion; this is uncoordinated
and causes data corruption.

Dave Chinner fixed this for xfs by simply serializing all
unaligned asynchronous direct IO.  I've done the same here.
The difference is that we only wait on conversions, not all IO.
This is a very big hammer, and I'm not very pleased with
stuffing this into ext4_file_write().  But since ext4 is
DIO_LOCKING, we need to serialize it at this high level.

I tried to move this into ext4_ext_direct_IO, but by then
we have the i_mutex already, and we will wait on the
work queue to do conversions - which must also take the
i_mutex.  So that won't work.

This was originally exposed by qemu-kvm installing to
a raw disk image with a normal sector-63 alignment.  I've
tested a backport of this patch with qemu, and it does
avoid the corruption.  It is also quite a lot slower
(14 min for package installs, vs. 8 min for well-aligned)
but I'll take slow correctness over fast corruption any day.

Mingming suggested that we can track outstanding
conversions, and wait on those so that non-sparse
files won't be affected, and I've implemented that here;
unaligned AIO to nonsparse files won't take a perf hit.

[tytso@mit.edu: Keep the mutex as a hashed array instead
 of bloating the ext4 inode]

[tytso@mit.edu: Fix up namespace issues so that global
 variables are protected with an "ext4_" prefix.]
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Change "especiially" to "especially".

Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: NTao Ma <boyu.mt@taobao.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Currently all filesystems except XFS implement fallocate asynchronously,
while XFS forced a commit.  Both of these are suboptimal - in case of O_SYNC
I/O we really want our allocation on disk, especially for the !KEEP_SIZE
case where we actually grow the file with user-visible zeroes.  On the
other hand always commiting the transaction is a bad idea for fast-path
uses of fallocate like for example in recent Samba versions.   Given
that block allocation is a data plane operation anyway change it from
an inode operation to a file operation so that we have the file structure
available that lets us check for O_SYNC.

This also includes moving the code around for a few of the filesystems,
and remove the already unnedded S_ISDIR checks given that we only wire
up fallocate for regular files.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Instead of various home grown checks that might need updates for new
flags just check for any bit outside the mask of the features supported
by the filesystem.  This makes the check future proof for any newly
added flag.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Ext4 doesn't have the ability to punch holes yet, so make sure we return
EOPNOTSUPP if we try to use hole punching through fallocate.  This support can
be added later.  Thanks,
Acked-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Since check_eofblocks_fl() only uses the m_lblk portion of the map
structure, we may as well pass that directly, rather than passing the
entire map, which IMHO obfuscates what parameters check_eofblocks_fl()
cares about.  Not a big deal, but seems tidier and less confusing, to
me.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Ted first found the bug when running 2.6.36 kernel with dioread_nolock
mount option that xfstests #13 complained about wrong file size during fsck.
However, the bug exists in the older kernels as well although it is
somehow harder to trigger.

The problem is that ext4_end_io_work() can happen after we have truncated an
inode to a smaller size. Then when ext4_end_io_work() calls 
ext4_convert_unwritten_extents(), we may reallocate some blocks that have 
been truncated, so the inode size becomes inconsistent with the allocated
blocks. 

The following patch flushes the i_completed_io_list during truncate to reduce 
the risk that some pending end_io requests are executed later and convert 
already truncated blocks to initialized. 

Note that although the fix helps reduce the problem a lot there may still 
be a race window between vmtruncate() and ext4_end_io_work(). The fundamental
problem is that if vmtruncate() is called without either i_mutex or i_alloc_sem
held, it can race with an ongoing write request so that the io_end request is
processed later when the corresponding blocks have been truncated.

Ted and I have discussed the problem offline and we saw a few ways to fix
the race completely:

a) We guarantee that i_mutex lock and i_alloc_sem write lock are both hold 
whenever vmtruncate() is called. The i_mutex lock prevents any new write
requests from entering writeback and the i_alloc_sem prevents the race
from ext4_page_mkwrite(). Currently we hold both locks if vmtruncate()
is called from do_truncate(), which is probably the most common case.
However, there are places where we may call vmtruncate() without holding
either i_mutex or i_alloc_sem. I would like to ask for other people's
opinions on what locks are expected to be held before calling vmtruncate().
There seems a disagreement among the callers of that function.

b) We change the ext4 write path so that we change the extent tree to contain 
the newly allocated blocks and update i_size both at the same time --- when 
the write of the data blocks is completed.

c) We add some additional locking to synchronize vmtruncate() and 
ext4_end_io_work(). This approach may have performance implications so we
need to be careful.

All of the above proposals may require more substantial changes, so
we may consider to take the following patch as a bandaid.
Signed-off-by: NJiaying Zhang <jiayingz@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

We can encode the ec_type information by using ee_len == 0 to denote
EXT4_EXT_CACHE_NO, ee_start == 0 to denote EXT4_EXT_CACHE_GAP, and if
neither is true, then the cache type must be EXT4_EXT_CACHE_EXTENT.
This allows us to reduce the size of ext4_ext_inode by another 8
bytes.  (ec_type is 4 bytes, plus another 4 bytes of padding)
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

This fixes a number of places where we used sector_t instead of
ext4_lblk_t for logical blocks, which for ext4 are still 32-bit data
types.  No point wasting space in the ext4_inode_info structure, and
requiring 64-bit arithmetic on 32-bit systems, when it isn't
necessary.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

ext4_ext_find_goal() returns an ideal physical block number that the block
allocator tries to allocate first. However, if a required file offset is
smaller than the existing extent's one, ext4_ext_find_goal() returns
a wrong block number because it may overflow at
"block - le32_to_cpu(ex->ee_block)". This patch fixes the problem.

ext4_ext_find_goal() will also return a wrong block number in case
a file offset of the existing extent is too big. In this case,
the ideal physical block number is fixed in ext4_mb_initialize_context(),
so it's no problem.

reproduce:
# dd if=/dev/zero of=/mnt/mp1/tmp bs=127M count=1 oflag=sync
# dd if=/dev/zero of=/mnt/mp1/file bs=512K count=1 seek=1 oflag=sync
# filefrag -v /mnt/mp1/file
Filesystem type is: ef53
File size of /mnt/mp1/file is 1048576 (256 blocks, blocksize 4096)
 ext logical physical expected length flags
   0     128    67456             128 eof
/mnt/mp1/file: 2 extents found
# rm -rf /mnt/mp1/tmp
# echo $((512*4096)) > /sys/fs/ext4/loop0/mb_stream_req
# dd if=/dev/zero of=/mnt/mp1/file bs=512K count=1 oflag=sync conv=notrunc

result (linux-2.6.37-rc2 + ext4 patch queue):
# filefrag -v /mnt/mp1/file
Filesystem type is: ef53
File size of /mnt/mp1/file is 1048576 (256 blocks, blocksize 4096)
 ext logical physical expected length flags
   0       0    33280             128 
   1     128    67456    33407    128 eof
/mnt/mp1/file: 2 extents found

result(apply this patch):
# filefrag -v /mnt/mp1/file
Filesystem type is: ef53
File size of /mnt/mp1/file is 1048576 (256 blocks, blocksize 4096)
 ext logical physical expected length flags
   0       0    66560             128 
   1     128    67456    66687    128 eof
/mnt/mp1/file: 2 extents found
Signed-off-by: NKazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

"gadget", "through", "command", "maintain", "maintain", "controller", "address",
"between", "initiali[zs]e", "instead", "function", "select", "already",
"equal", "access", "management", "hierarchy", "registration", "interest",
"relative", "memory", "offset", "already",
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

When I compiled 2.6.36-rc3 kernel with EXT4FS_DEBUG definition, I got
the following compile error.

  CC [M]  fs/ext4/extents.o
fs/ext4/extents.c: In function 'ext4_fallocate':
fs/ext4/extents.c:3772: error: 'block' undeclared (first use in this function)
fs/ext4/extents.c:3772: error: (Each undeclared identifier is reported only once
fs/ext4/extents.c:3772: error: for each function it appears in.)
make[2]: *** [fs/ext4/extents.o] Error 1

The patch fixes this problem.
Signed-off-by: NKazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Cleanup namespace leaks from fs/ext4 and the inline trivial functions
ext4_{ext,idx}_pblock() and ext4_{ext,idx}_store_pblock() since the
code size actually shrinks when we make these functions inline,
they're so trivial.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

These functions have no need to be exported beyond file context.

No functions needed to be moved for this commit; just some function
declarations changed to be static and removed from header files.

(A similar patch was submitted by Eric Sandeen, but I wanted to handle
code movement in separate patches to make sure code changes didn't
accidentally get dropped.)
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Call the block I/O layer directly instad of going through the buffer
layer.  This should give us much better performance and scalability,
as well as lowering our CPU utilization when doing buffered writeback.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Change ext4_ext_zeroout to use sb_issue_zeroout instead of its
own approach to zero out extents.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

It turns out we have several problems with how EOFBLOCKS_FL is
handled.  First of all, there was a fencepost error where we were not
clearing the EOFBLOCKS_FL when fill in the last uninitialized block,
but rather when we allocate the next block _after_ the uninitalized
block.  Secondly we were not testing to see if we needed to clear the
EOFBLOCKS_FL when writing to the file O_DIRECT or when were converting
an uninitialized block (which is the most common case).

Google-Bug-Id: 2928259
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

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