Commit Graph

102 Commits

Author SHA1 Message Date
Theodore Ts'o
ac51d83705 ext4: calculate journal credits correctly
This fixes a 2.6.27 regression which was introduced in commit a02908f1.

We weren't passing the chunk parameter down to the two subections,
ext4_indirect_trans_blocks() and ext4_ext_index_trans_blocks(), with
the result that massively overestimate the amount of credits needed by
ext4_da_writepages, especially in the non-extents case.  This causes
failures especially on /boot partitions, which tend to be small and
non-extent using since GRUB doesn't handle extents.

This patch fixes the bug reported by Joseph Fannin at:
http://bugzilla.kernel.org/show_bug.cgi?id=11964

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-11-06 16:49:36 -05:00
Theodore Ts'o
f287a1a561 ext4: Remove automatic enabling of the HUGE_FILE feature flag
If the HUGE_FILE feature flag is not set, don't allow the creation of
large files, instead of automatically enabling the feature flag.
Recent versions of mke2fs will set the HUGE_FILE flag automatically
anyway for ext4 filesystems.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-10-16 22:50:48 -04:00
Aneesh Kumar K.V
22208dedbd ext4: Fix file fragmentation during large file write.
The range_cyclic writeback mode uses the address_space writeback_index
as the start index for writeback.  With delayed allocation we were
updating writeback_index wrongly resulting in highly fragmented file.
This patch reduces the number of extents reduced from 4000 to 27 for a
3GB file.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2008-10-16 10:10:36 -04:00
Aneesh Kumar K.V
af6f029d38 ext4: Use tag dirty lookup during mpage_da_submit_io
This enables us to drop the range_cont writeback mode
use from ext4_da_writepages.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2008-10-14 09:20:19 -04:00
Theodore Ts'o
03010a3350 ext4: Rename ext4dev to ext4
The ext4 filesystem is getting stable enough that it's time to drop
the "dev" prefix.  Also remove the requirement for the TEST_FILESYS
flag.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-10-10 20:02:48 -04:00
Eric Sandeen
6873fa0de1 Hook ext4 to the vfs fiemap interface.
ext4_ext_walk_space() was reinstated to be used for iterating over file
extents with a callback; it is used by the ext4 fiemap implementation.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: linux-ext4@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
2008-10-07 00:46:36 -04:00
Theodore Ts'o
c2ea3fde61 ext4: Remove old legacy block allocator
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-10-10 09:40:52 -04:00
Theodore Ts'o
240799cdf2 ext4: Use readahead when reading an inode from the inode table
With modern hard drives, reading 64k takes roughly the same time as
reading a 4k block.  So request readahead for adjacent inode table
blocks to reduce the time it takes when iterating over directories
(especially when doing this in htree sort order) in a cold cache case.
With this patch, the time it takes to run "git status" on a kernel
tree after flushing the caches via "echo 3 > /proc/sys/vm/drop_caches"
is reduced by 21%.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-10-09 23:53:47 -04:00
Aneesh Kumar K.V
cf17fea657 ext4: Properly update i_disksize.
With delayed allocation we use i_data_sem to update i_disksize.  We need
to update i_disksize only if the new size specified is greater than the
current value and we need to make sure we don't race with other
i_disksize update.  With delayed allocation we will switch to the
write_begin function for non-delayed allocation if we are low on free
blocks.  This means the write_begin function for non-delayed allocation
also needs to use the same locking.

We also need to check and update i_disksize even if the new size is less
that inode.i_size because of delayed allocation.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-09-13 13:06:18 -04:00
Aneesh Kumar K.V
ae4d537211 ext4: truncate block allocated on a failed ext4_write_begin
For blocksize < pagesize we need to remove blocks that got allocated in
block_write_begin() if we fail with ENOSPC for later blocks.
block_write_begin() internally does this if it allocated pages locally.
This makes sure we don't have blocks outside inode.i_size during ENOSPC.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-09-13 13:10:25 -04:00
Aneesh Kumar K.V
df22291ff0 ext4: Retry block allocation if we have free blocks left
When we truncate files, the meta-data blocks released are not reused
untill we commit the truncate transaction.  That means delayed get_block
request will return ENOSPC even if we have free blocks left.  Force a
journal commit and retry block allocation if we get ENOSPC with free
blocks left.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-09-08 23:05:34 -04:00
Aneesh Kumar K.V
166348dd37 ext4: Don't add the inode to journal handle until after the block is allocated
Make sure we don't add the inode to the journal handle until after the
block allocation, so that a journal commit will not include the inode in
case of block allocation failure.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-09-08 23:08:40 -04:00
Aneesh Kumar K.V
79f0be8d2e ext4: Switch to non delalloc mode when we are low on free blocks count.
The delayed allocation code allocates blocks during writepages(), which
can not handle block allocation failures.  To deal with this, we switch
away from delayed allocation mode when we are running low on free
blocks.  This also allows us to avoid needing to reserve a large number
of meta-data blocks in case all of the requested blocks are
discontiguous.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-10-08 23:13:30 -04:00
Aneesh Kumar K.V
6bc6e63fcd ext4: Add percpu dirty block accounting.
This patch adds dirty block accounting using percpu_counters.  Delayed
allocation block reservation is now done by updating dirty block
counter.  In a later patch we switch to non delalloc mode if the
filesystem free blocks is greater than 150% of total filesystem dirty
blocks

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao<cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-10-10 09:39:00 -04:00
Aneesh Kumar K.V
030ba6bc67 ext4: Retry block reservation
During block reservation if we don't have enough blocks left, retry
block reservation with smaller block counts.  This makes sure we try
fallocate and DIO with smaller request size and don't fail early.  The
delayed allocation reservation cannot try with smaller block count. So
retry block reservation to handle temporary disk full conditions.  Also
print free blocks details if we fail block allocation during writepages.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-09-08 23:14:50 -04:00
Aneesh Kumar K.V
a30d542a00 ext4: Make sure all the block allocation paths reserve blocks
With delayed allocation we need to make sure block are reserved before
we attempt to allocate them. Otherwise we get block allocation failure
(ENOSPC) during writepages which cannot be handled. This would mean
silent data loss (We do a printk stating data will be lost). This patch
updates the DIO and fallocate code path to do block reservation before
block allocation. This is needed to make sure parallel DIO and fallocate
request doesn't take block out of delayed reserve space.

When free blocks count go below a threshold we switch to a slow patch
which looks at other CPU's accumulated percpu counter values.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-10-09 10:56:23 -04:00
Aneesh Kumar K.V
c4a0c46ec9 ext4: invalidate pages if delalloc block allocation fails.
We are a bit agressive in invalidating all the pages. But
it is ok because we really don't know why the block allocation
failed and it is better to come of the writeback path
so that user can look for more info.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2008-08-19 21:08:18 -04:00
Theodore Ts'o
af5bc92dde ext4: Fix whitespace checkpatch warnings/errors
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-09-08 22:25:24 -04:00
Aneesh Kumar K.V
5e745b041f ext4: Fix small file fragmentation
For small file block allocations, mballoc uses per cpu prealloc
space.  Use goal block when searching for the right prealloc
space.  Also make sure ext4_da_writepages tries to write
all the pages for small files in single attempt

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-08-18 18:00:57 -04:00
Mingming Cao
525f4ed8dc ext4: journal credit fix for the delayed allocation's writepages() function
Previous delalloc writepages implementation started a new transaction
outside of a loop which called get_block() to do the block allocation.
Since we didn't know exactly how many blocks would need to be allocated,
the estimated journal credits required was very conservative and caused
many issues.

With the reworked delayed allocation, a new transaction is created for
each get_block(), thus we don't need to guess how many credits for the
multiple chunk of allocation.  We start every transaction with enough
credits for inserting a single exent.  When estimate the credits for
indirect blocks to allocate a chunk of blocks, we need to know the
number of data blocks to allocate.  We use the total number of reserved
delalloc datablocks; if that is too big, for non-extent files, we need
to limit the number of blocks to EXT4_MAX_TRANS_BLOCKS.

Code cleanup from Aneesh.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Reviewed-off-by:  Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-08-19 22:15:58 -04:00
Aneesh Kumar K.V
a1d6cc563b ext4: Rework the ext4_da_writepages() function
With the below changes we reserve credit needed to insert only one
extent resulting from a call to single get_block.  This makes sure we
don't take too much journal credits during writeout.  We also don't
limit the pages to write.  That means we loop through the dirty pages
building largest possible contiguous block request.  Then we issue a
single get_block request.  We may get less block that we requested.  If
so we would end up not mapping some of the buffer_heads.  That means
those buffer_heads are still marked delay.  Later in the writepage
callback via __mpage_writepage we redirty those pages.

We should also not limit/throttle wbc->nr_to_write in the filesystem
writepages callback. That cause wrong behaviour in
generic_sync_sb_inodes caused by wbc->nr_to_write being <= 0

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-08-19 21:55:02 -04:00
Mingming Cao
f3bd1f3fa8 ext4: journal credits reservation fixes for DIO, fallocate
DIO and fallocate credit calculation is different than writepage, as
they do start a new journal right for each call to ext4_get_blocks_wrap().
This patch uses the helper function in DIO and fallocate case, passing
a flag indicating that the modified data are contigous thus could account
less indirect/index blocks.

This patch also fixed the journal credit reservation for direct I/O
(DIO).  Previously the estimated credits for DIO only was calculated for
non-extent files, which was not enough if the file is extent-based.

Also fixed was fallocate double-counting credits for modifying the the
superblock.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-08-19 22:16:03 -04:00
Mingming Cao
a02908f19c ext4: journal credits calulation cleanup and fix for non-extent writepage
When considering how many journal credits are needed for modifying a
chunk of data, we need to account for the super block, inode block,
quota blocks and xattr block, indirect/index blocks, also, group bitmap
and group descriptor blocks for new allocation (including data and
indirect/index blocks). There are many places in ext4 do the calculation
on their own and often missed one or two meta blocks, and often they
assume single block allocation, and did not considering the multile
chunk of allocation case.

This patch is trying to cleanup current journal credit code, provides
some common helper funtion to calculate the journal credits, to be used
for writepage, writepages, DIO, fallocate, migration, defrag, and for
both nonextent and extent files.

This patch modified the writepage/write_begin credit caculation for
nonextent files, to use the new helper function. It also fixed the
problem that writepage on nonextent files did not consider the case
blocksize <pagesize, thus could possibelly need multiple block
allocation in a single transaction.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-08-19 22:16:07 -04:00
Mingming Cao
cd21322616 ext4: Fix delalloc release block reservation for truncate
Ext4 will release the reserved blocks for delayed allocations when
inode is truncated/unlinked.  If there is no reserved block at all, we
shouldn't need to do so.  But current code still tries to release the
reserved blocks regardless whether the counters's value is 0.
Continue to do that causes the later calculation to go wrong and a
kernel BUG_ON() caught that. This doesn't happen for extent-based
files, as the calculation for 0 reserved blocks was right for extent
based file.

This patch fixed the kernel BUG() due to above reason.  It adds checks
for 0 to avoid unnecessary release and fix calculation for non-extent
files.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-08-19 22:16:59 -04:00
Theodore Ts'o
b4df203085 ext4: Fix potential truncate BUG due to i_prealloc_list being non-empty
We need to call ext4_discard_reservation() earlier in ext4_truncate(),
to avoid a BUG() in ext4_mb_return_to_preallocation(), which is called
(ultimately) by ext4_free_blocks().  So we must ditch the blocks on
i_prealloc_list before we start freeing the data blocks.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-08-13 21:44:34 -04:00
Aneesh Kumar K.V
bf068ee266 ext4: Handle unwritten extent properly with delayed allocation
When using fallocate the buffer_heads are marked unwritten and unmapped.
We need to map them in the writepages after a get_block.  Otherwise we
split the uninit extents, but never write the content to disk.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-08-19 22:16:43 -04:00
Eric Sandeen
7d55992d60 ext4: remove write-only variables from ext4_ordered_write_end
The variables 'from' and 'to' are not used anywhere.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-08-02 21:22:18 -04:00
Theodore Ts'o
2b2d6d0197 ext4: Cleanup whitespace and other miscellaneous style issues
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-26 16:15:44 -04:00
Aneesh Kumar K.V
12219aea6b ext4: Cleanup the block reservation code path
The truncate patch should not use the i_allocated_meta_blocks
value. So add seperate functions to be used in the truncate
and alloc path. We also need to release the meta-data block
that we reserved for the blocks that we are truncating.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2008-07-17 16:12:08 -04:00
Theodore Ts'o
bc965ab3f2 ext4: Fix lack of credits BUG() when deleting a badly fragmented inode
The extents codepath for ext4_truncate() requests journal transaction
credits in very small chunks, requesting only what is needed.  This
means there may not be enough credits left on the transaction handle
after ext4_truncate() returns and then when ext4_delete_inode() tries
finish up its work, it may not have enough transaction credits,
causing a BUG() oops in the jbd2 core.

Also, reserve an extra 2 blocks when starting an ext4_delete_inode()
since we need to update the inode bitmap, as well as update the
orphaned inode linked list.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-08-02 21:10:38 -04:00
Eric Sandeen
d5a0d4f732 ext4: fix ext4_da_write_begin error path
ext4_da_write_begin needs to call journal_stop before returning,
if the page allocation fails.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Acked-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-08-02 18:51:06 -04:00
Hidehiro Kawai
9c83a923c6 ext4: don't read inode block if the buffer has a write error
A transient I/O error can corrupt inode data.  Here is the scenario:

(1) update inode_A at the block_B
(2) pdflush writes out new inode_A to the filesystem, but it results
    in write I/O error, at this point, BH_Uptodate flag of the buffer
    for block_B is cleared and BH_Write_EIO is set
(3) create new inode_C which located at block_B, and
    __ext4_get_inode_loc() tries to read on-disk block_B because the
    buffer is not uptodate
(4) if it can read on-disk block_B successfully, inode_A is
    overwritten by old data

This patch makes __ext4_get_inode_loc() not read the inode block if the
buffer has BH_Write_EIO flag.  In this case, the buffer should have the
latest information, so setting the uptodate flag to the buffer (this
avoids WARN_ON_ONCE() in mark_buffer_dirty().)

According to this change, we would need to test BH_Write_EIO flag for the
error checking.  Currently nobody checks write I/O errors on metadata
buffers, but it will be done in other patches I'm working on.

Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Cc: sugita <yumiko.sugita.yf@hitachi.com>
Cc: Satoshi OSHIMA <satoshi.oshima.fk@hitachi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Jan Kara <jack@ucw.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2008-07-26 16:39:26 -04:00
Hisashi Hifumi
8ab22b9abb vfs: pagecache usage optimization for pagesize!=blocksize
When we read some part of a file through pagecache, if there is a
pagecache of corresponding index but this page is not uptodate, read IO
is issued and this page will be uptodate.

I think this is good for pagesize == blocksize environment but there is
room for improvement on pagesize != blocksize environment.  Because in
this case a page can have multiple buffers and even if a page is not
uptodate, some buffers can be uptodate.

So I suggest that when all buffers which correspond to a part of a file
that we want to read are uptodate, use this pagecache and copy data from
this pagecache to user buffer even if a page is not uptodate.  This can
reduce read IO and improve system throughput.

I wrote a benchmark program and got result number with this program.

This benchmark do:

  1: mount and open a test file.

  2: create a 512MB file.

  3: close a file and umount.

  4: mount and again open a test file.

  5: pwrite randomly 300000 times on a test file.  offset is aligned
     by IO size(1024bytes).

  6: measure time of preading randomly 100000 times on a test file.

The result was:
	2.6.26
        330 sec

	2.6.26-patched
        226 sec

Arch:i386
Filesystem:ext3
Blocksize:1024 bytes
Memory: 1GB

On ext3/4, a file is written through buffer/block.  So random read/write
mixed workloads or random read after random write workloads are optimized
with this patch under pagesize != blocksize environment.  This test result
showed this.

The benchmark program is as follows:

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>

#define LEN 1024
#define LOOP 1024*512 /* 512MB */

main(void)
{
	unsigned long i, offset, filesize;
	int fd;
	char buf[LEN];
	time_t t1, t2;

	if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) {
		perror("cannot mount\n");
		exit(1);
	}
	memset(buf, 0, LEN);
	fd = open("/root/test1/testfile", O_CREAT|O_RDWR|O_TRUNC);
	if (fd < 0) {
		perror("cannot open file\n");
		exit(1);
	}
	for (i = 0; i < LOOP; i++)
		write(fd, buf, LEN);
	close(fd);
	if (umount("/root/test1/") < 0) {
		perror("cannot umount\n");
		exit(1);
	}
	if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) {
		perror("cannot mount\n");
		exit(1);
	}
	fd = open("/root/test1/testfile", O_RDWR);
	if (fd < 0) {
		perror("cannot open file\n");
		exit(1);
	}

	filesize = LEN * LOOP;
	for (i = 0; i < 300000; i++){
		offset = (random() % filesize) & (~(LEN - 1));
		pwrite(fd, buf, LEN, offset);
	}
	printf("start test\n");
	time(&t1);
	for (i = 0; i < 100000; i++){
		offset = (random() % filesize) & (~(LEN - 1));
		pread(fd, buf, LEN, offset);
	}
	time(&t2);
	printf("%ld sec\n", t2-t1);
	close(fd);
	if (umount("/root/test1/") < 0) {
		perror("cannot umount\n");
		exit(1);
	}
}

Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Jan Kara <jack@ucw.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28 16:30:21 -07:00
Mingming Cao
3e3398a08d ext4: delayed allocation i_blocks fix for stat
Right now i_blocks is not getting updated until the blocks are actually
allocaed on disk.  This means with delayed allocation, right after files
are copied, "ls -sF" shoes the file as taking 0 blocks on disk.  "du"
also shows the files taking zero space, which is highly confusing to the
user.

Since delayed allocation already keeps track of per-inode total
number of blocks that are subject to delayed allocation, this patch fix
this by using that to adjust the value returned by stat(2). When real
block allocation is done, the i_blocks will get updated. Since the
reserved blocks for delayed allocation will be decreased, this will be
keep value returned by stat(2) consistent.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Mingming Cao
632eaeab1f ext4: fix delalloc i_disksize early update issue
Ext4_da_write_end() used walk_page_buffers() with a callback function of
ext4_bh_unmapped_or_delay() to check if it extended the file size
without allocating any blocks (since in this case i_disksize needs to be
updated).  However, this is didn't work proprely because the buffer head
has not been marked dirty yet --- this is done later in
block_commit_write() --- which caused ext4_bh_unmapped_or_delay() to
always return false.

In addition, walk_page_buffers() checks all of the buffer heads covering
the page, and the only buffer_head that should be checked is the one
covering the end of the write.  Otherwise, given a 1k blocksize
filesystem and a 4k page size, the buffer head covering the first 1k
stripe of the file could be unmapped (because it was a sparse file), and
the second or third buffer_head covering that page could be mapped, and
using walk_page_buffers() would fail in this case since it would stop at
the first unmapped buffer_head and return true.

The core problem is that walk_page_buffers() was intended to do work in
a callback function, and a non-zero return value indicated a failure,
which termined the walk of the buffer heads covering the page.  It was
not intended to be used with a boolean function, such as
ext4_bh_unmapped_or_delay().

Add addtional fix from Aneesh to protect i_disksize update rave with truncate.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Aneesh Kumar K.V
f0e6c98593 ext4: Handle page without buffers in ext4_*_writepage()
It can happen that buffers are removed from the page before it gets
marked dirty and then is passed to writepage().  In writepage() we just
initialize the buffers and check whether they are mapped and non
delay. If they are mapped and non delay we write the page. Otherwise we
mark them dirty.  With this change we don't do block allocation at all
in ext4_*_write_page.

writepage() can get called under many condition and with a locking order
of journal_start -> lock_page, we should not try to allocate blocks in
writepage() which get called after taking page lock.  writepage() can
get called via shrink_page_list even with a journal handle which was
created for doing inode update.  For example when doing
ext4_da_write_begin we create a journal handle with credit 1 expecting a
i_disksize update for the inode. But ext4_da_write_begin can cause
shrink_page_list via _grab_page_cache. So having a valid handle via
ext4_journal_current_handle is not a guarantee that we can use the
handle for block allocation in writepage, since we shouldn't be using
credits that had been reserved for other updates.  That it could result
in we running out of credits when we update inodes.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Aneesh Kumar K.V
cd1aac3292 ext4: Add ordered mode support for delalloc
This provides a new ordered mode implementation which gets rid of using
buffer heads to enforce the ordering between metadata change with the
related data chage.  Instead, in the new ordering mode, it keeps track
of all of the inodes touched by each transaction on a list, and when
that transaction is committed, it flushes all of the dirty pages for
those inodes.  In addition, the new ordered mode reverses the lock
ordering of the page lock and transaction lock, which provides easier
support for delayed allocation.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Mingming Cao
61628a3f3a ext4: Invert lock ordering of page_lock and transaction start in delalloc
With the reverse locking, we need to start a transation before taking
the page lock, so in ext4_da_writepages() we need to break the write-out
into chunks, and restart the journal for each chunck to ensure the
write-out fits in a single transaction.

Updated patch from Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
which fixes delalloc sync hang with journal lock inversion, and address
the performance regression issue.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Mingming Cao
d2a1763791 ext4: delayed allocation ENOSPC handling
This patch does block reservation for delayed
allocation, to avoid ENOSPC later at page flush time.

Blocks(data and metadata) are reserved at da_write_begin()
time, the freeblocks counter is updated by then, and the number of
reserved blocks is store in per inode counter.
        
At the writepage time, the unused reserved meta blocks are returned
back. At unlink/truncate time, reserved blocks are properly released.

Updated fix from  Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
to fix the oldallocator block reservation accounting with delalloc, added
lock to guard the counters and also fix the reservation for meta blocks.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2008-07-14 17:52:37 -04:00
Alex Tomas
64769240bd ext4: Add delayed allocation support in data=writeback mode
Updated with fixes from Mingming Cao <cmm@us.ibm.com> to unlock and
release the page from page cache if the delalloc write_begin failed, and
properly handle preallocated blocks.  Also added a fix to clear
buffer_delay in block_write_full_page() after allocating a delayed
buffer.

Updated with fixes from Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
to update i_disksize properly and to add bmap support for delayed
allocation.

Updated with a fix from Valerie Clement <valerie.clement@bull.net> to
avoid filesystem corruption when the filesystem is mounted with the
delalloc option and blocksize < pagesize.

Signed-off-by: Alex Tomas <alex@clusterfs.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by:  Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2008-07-11 19:27:31 -04:00
Jan Kara
678aaf4814 ext4: Use new framework for data=ordered mode in JBD2
This patch makes ext4 use inode-based implementation of data=ordered mode
in JBD2. It allows us to unify some data=ordered and data=writeback paths
(especially writepage since we don't have to start a transaction anymore)
and remove some buffer walking.

Updated fix from Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
to fix file system hang due to corrupt jinode values.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Jan Kara
cf108bca46 ext4: Invert the locking order of page_lock and transaction start
This changes are needed to support data=ordered mode handling via
inodes.  This enables us to get rid of the journal heads and buffer
heads for data buffers in the ordered mode.  With the changes, during
tranasaction commit we writeout the inode pages using the
writepages()/writepage(). That implies we take page lock during
transaction commit. This can cause a deadlock with the locking order
page_lock -> jbd2_journal_start, since the jbd2_journal_start can wait
for the journal_commit to happen and the journal_commit now needs to
take the page lock. To avoid this dead lock reverse the locking order.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Aneesh Kumar K.V
2e9ee85035 ext4: Use page_mkwrite vma_operations to get mmap write notification.
We would like to get notified when we are doing a write on mmap section.
This is needed with respect to preallocated area. We split the preallocated
area into initialzed extent and uninitialzed extent in the call back. This
let us handle ENOSPC better. Otherwise we get ENOSPC in the writepage and
that would result in data loss. The changes are also needed to handle ENOSPC
when writing to an mmap section of files with holes.

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Aneesh Kumar K.V
654b4908bc ext4: cleanup block allocator
Move the code related to block allocation to a single function and add helper
funtions to differient allocation for data and meta data blocks

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Aneesh Kumar K.V
7061eba75c ext4: Use inode preallocation with -o noextents
When mballoc is enabled, block allocation for old block-based
files are allocated using mballoc allocator instead of old
block-based allocator. The old ext3 block reservation is turned
off when mballoc is turned on.

However, the in-core preallocation is not enabled for block-based/
non-extent based file block allocation. This result in performance
regression, as now we don't have "reservation" ore in-core preallocation
to prevent interleaved fragmentation in multiple writes workload.

This patch fix this by enable per inode in-core preallocation
for non extent files when mballoc is used.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Duane Griffin
71dc8fbcf5 ext4: handle deleting corrupted indirect blocks
While freeing indirect blocks we attach a journal head to the parent buffer
head, free the blocks, then journal the parent. If the indirect block list
is corrupted and points to the parent the journal head will be detached
when the block is cleared, causing an OOPS.

Check for that explicitly and handle it gracefully.

This patch fixes the third case (image hdb.20000057.nullderef.gz)
reported in http://bugzilla.kernel.org/show_bug.cgi?id=10882.

Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Duane Griffin
91ef4caf80 ext4: handle corrupted orphan list at mount
If the orphan node list includes valid, untruncatable nodes with nlink > 0
the ext4_orphan_cleanup loop which attempts to delete them will not do so,
causing it to loop forever. Fix by checking for such nodes in the
ext4_orphan_get function.

This patch fixes the second case (image hdb.20000009.softlockup.gz)
reported in http://bugzilla.kernel.org/show_bug.cgi?id=10882.

Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2008-07-11 19:27:31 -04:00
Roel Kluin
f8a87d8930 ext4: fix test ext_generic_write_end() copied return value
'copied' is unsigned, whereas 'ret2' is not. The test (copied < 0) fails

Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-04-29 22:01:18 -04:00
Christoph Hellwig
3dcf54515a ext4: move headers out of include/linux
Move ext4 headers out of include/linux.  This is just the trivial move,
there's some more thing that could be done later. 

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-04-29 18:13:32 -04:00
Harvey Harrison
46e665e9d2 ext4: replace remaining __FUNCTION__ occurrences
__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2008-04-17 10:38:59 -04:00