Commit Graph

203 Commits

Author SHA1 Message Date
Yongqiang Yang
1b16da77f9 ext4: teach ext4_ext_split to calculate extents efficiently
Make ext4_ext_split() get extents to be moved by calculating in a statement
instead of counting in a loop.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-25 17:41:48 -04:00
Vivek Haldar
556b27abf7 ext4: do not normalize block requests from fallocate()
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: Vivek Haldar <haldar@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-25 07:41:54 -04:00
Allison Henderson
a4bb6b64e3 ext4: enable "punch hole" functionality
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: Allison Henderson <achender@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
2011-05-25 07:41:50 -04:00
Allison Henderson
e861304b8e ext4: add "punch hole" flag to ext4_map_blocks()
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: Allison Henderson <achender@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
2011-05-25 07:41:46 -04:00
Allison Henderson
d583fb87a3 ext4: punch out extents
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: Allison Henderson <achender@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-25 07:41:43 -04:00
Allison Henderson
55f020db66 ext4: add flag to ext4_has_free_blocks
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: Allison Henderson <achender@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
2011-05-25 07:41:26 -04:00
Yongqiang Yang
b221349fa8 ext4: fix ext4_ext_fiemap_cb() to handle blocks before request range correctly
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: Amir Goldstein <amir73il@users.sourceforge.net>
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-24 11:36:58 -04:00
Eric Gouriou
f6d2f6b327 ext4: fix unbalanced up_write() in ext4_ext_truncate() error path
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: Eric Gouriou <egouriou@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-22 21:33:00 -04:00
Vivek Haldar
77f4135f2a ext4: count hits/misses of extent cache and expose in sysfs
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: Vivek Haldar <haldar@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-22 21:24:16 -04:00
Yongqiang Yang
93917411be ext4: make ext4_split_extent() handle error correctly
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
2011-05-22 20:49:12 -04:00
Allison Henderson
9b940f8e8c ext4: ext4_ext_convert_to_initialized bug found in extended FSX testing
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: Allison Henderson <achender@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-16 10:11:09 -04:00
Yongqiang Yang
667eff35a1 ext4: reimplement convert and split_unwritten
Reimplement ext4_ext_convert_to_initialized() and
ext4_split_unwritten_extents() using ext4_split_extent()

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Tested-by: Allison Henderson <achender@linux.vnet.ibm.com>
2011-05-03 12:25:07 -04:00
Yongqiang Yang
47ea3bb59c ext4: add ext4_split_extent_at() and ext4_split_extent()
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: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Tested-by: Allison Henderson <achender@linux.vnet.ibm.com>
2011-05-03 12:23:07 -04:00
Yongqiang Yang
197217a5af ext4: add a function merging extents right and left
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: Yongqiang Yang <xiaoqiangnk@gmail.com>
Tested-by: Allison Henderson <achender@linux.vnet.ibm.com>
2011-05-03 11:45:29 -04:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Linus Torvalds
ae005cbed1 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (43 commits)
  ext4: fix a BUG in mb_mark_used during trim.
  ext4: unused variables cleanup in fs/ext4/extents.c
  ext4: remove redundant set_buffer_mapped() in ext4_da_get_block_prep()
  ext4: add more tracepoints and use dev_t in the trace buffer
  ext4: don't kfree uninitialized s_group_info members
  ext4: add missing space in printk's in __ext4_grp_locked_error()
  ext4: add FITRIM to compat_ioctl.
  ext4: handle errors in ext4_clear_blocks()
  ext4: unify the ext4_handle_release_buffer() api
  ext4: handle errors in ext4_rename
  jbd2: add COW fields to struct jbd2_journal_handle
  jbd2: add the b_cow_tid field to journal_head struct
  ext4: Initialize fsync transaction ids in ext4_new_inode()
  ext4: Use single thread to perform DIO unwritten convertion
  ext4: optimize ext4_bio_write_page() when no extent conversion is needed
  ext4: skip orphan cleanup if fs has unknown ROCOMPAT features
  ext4: use the nblocks arg to ext4_truncate_restart_trans()
  ext4: fix missing iput of root inode for some mount error paths
  ext4: make FIEMAP and delayed allocation play well together
  ext4: suppress verbose debugging information if malloc-debug is off
  ...

Fi up conflicts in fs/ext4/super.c due to workqueue changes
2011-03-25 09:57:41 -07:00
Sergey Senozhatsky
65922cb5ce ext4: unused variables cleanup in fs/ext4/extents.c
ext4 extents cleanup:

  . remove unused `*ex' from check_eofblocks_fl
  . remove unused `*eh' from ext4_ext_map_blocks


Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-03-23 14:08:27 -04:00
Jiaying Zhang
0562e0bad4 ext4: add more tracepoints and use dev_t in the trace buffer
- 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: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-03-21 21:38:05 -04:00
Yongqiang Yang
6d9c85eb70 ext4: make FIEMAP and delayed allocation play well together
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: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-02-27 17:25:47 -05:00
Peter Huewe
7dc576158d ext4: Fix sparse warning: Using plain integer as NULL pointer
This patch fixes the warning "Using plain integer as NULL pointer",
generated by sparse, by replacing the offending 0s with NULL.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-02-21 21:01:42 -05:00
Paul Bolle
fd018fe823 ext4: fix comment typo uninitized
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Reviewed-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-02-15 10:28:59 +01:00
Jiri Kosina
0a9d59a246 Merge branch 'master' into for-next 2011-02-15 10:24:31 +01:00
Eric Sandeen
e9e3bcecf4 ext4: serialize unaligned asynchronous DIO
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: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-02-12 08:17:34 -05:00
Tao Ma
b8d6568a12 ext4: Fix comment typo "especiially".
Change "especiially" to "especially".

Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-01-21 16:27:01 +01:00
Christoph Hellwig
2fe17c1075 fallocate should be a file operation
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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-17 02:25:31 -05:00
Christoph Hellwig
64c23e8687 make the feature checks in ->fallocate future proof
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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-17 02:25:30 -05:00
Linus Torvalds
b2034d474b Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (41 commits)
  fs: add documentation on fallocate hole punching
  Gfs2: fail if we try to use hole punch
  Btrfs: fail if we try to use hole punch
  Ext4: fail if we try to use hole punch
  Ocfs2: handle hole punching via fallocate properly
  XFS: handle hole punching via fallocate properly
  fs: add hole punching to fallocate
  vfs: pass struct file to do_truncate on O_TRUNC opens (try #2)
  fix signedness mess in rw_verify_area() on 64bit architectures
  fs: fix kernel-doc for dcache::prepend_path
  fs: fix kernel-doc for dcache::d_validate
  sanitize ecryptfs ->mount()
  switch afs
  move internal-only parts of ncpfs headers to fs/ncpfs
  switch ncpfs
  switch 9p
  pass default dentry_operations to mount_pseudo()
  switch hostfs
  switch affs
  switch configfs
  ...
2011-01-13 10:27:28 -08:00
Linus Torvalds
008d23e485 Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits)
  Documentation/trace/events.txt: Remove obsolete sched_signal_send.
  writeback: fix global_dirty_limits comment runtime -> real-time
  ppc: fix comment typo singal -> signal
  drivers: fix comment typo diable -> disable.
  m68k: fix comment typo diable -> disable.
  wireless: comment typo fix diable -> disable.
  media: comment typo fix diable -> disable.
  remove doc for obsolete dynamic-printk kernel-parameter
  remove extraneous 'is' from Documentation/iostats.txt
  Fix spelling milisec -> ms in snd_ps3 module parameter description
  Fix spelling mistakes in comments
  Revert conflicting V4L changes
  i7core_edac: fix typos in comments
  mm/rmap.c: fix comment
  sound, ca0106: Fix assignment to 'channel'.
  hrtimer: fix a typo in comment
  init/Kconfig: fix typo
  anon_inodes: fix wrong function name in comment
  fix comment typos concerning "consistent"
  poll: fix a typo in comment
  ...

Fix up trivial conflicts in:
 - drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c)
 - fs/ext4/ext4.h

Also fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.
2011-01-13 10:05:56 -08:00
Josef Bacik
d6dc8462f4 Ext4: fail if we try to use hole punch
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: Jan Kara <jack@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-01-12 20:16:44 -05:00
Eric Sandeen
d002ebf1d8 ext4: don't pass entire map to check_eofblocks_fl
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: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 13:03:35 -05:00
Jiaying Zhang
3889fd57ea ext4: flush the i_completed_io_list during ext4_truncate
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: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:47:05 -05:00
Theodore Ts'o
b05e6ae58a ext4: drop ec_type from the ext4_ext_cache structure
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: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:13:26 -05:00
Theodore Ts'o
01f49d0b9d ext4: use ext4_lblk_t instead of sector_t for logical blocks
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: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:13:03 -05:00
Kazuya Mio
ad4fb9cafe ext4: fix 32bit overflow in ext4_ext_find_goal()
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: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-01-10 12:12:28 -05:00
Uwe Kleine-König
b595076a18 tree-wide: fix comment/printk typos
"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: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-11-01 15:38:34 -04:00
Theodore Ts'o
a107e5a3a4 Merge branch 'next' into upstream-merge
Conflicts:
	fs/ext4/inode.c
	fs/ext4/mballoc.c
	include/trace/events/ext4.h
2010-10-27 23:44:47 -04:00
Kazuya Mio
a6371b636f ext4: fix compile error in ext4_fallocate()
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: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-27 21:30:15 -04:00
Theodore Ts'o
bf89d16f6e ext4: rename {ext,idx}_pblock and inline small extent functions
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: "Theodore Ts'o" <tytso@mit.edu>
2010-10-27 21:30:14 -04:00
Theodore Ts'o
1f109d5a17 ext4: make various ext4 functions be static
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: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-27 21:30:14 -04:00
Theodore Ts'o
bd2d0210cf ext4: use bio layer instead of buffer layer in mpage_da_submit_io
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: "Theodore Ts'o" <tytso@mit.edu>
2010-10-27 21:30:10 -04:00
Lukas Czerner
2407518de6 ext4: use sb_issue_zeroout in ext4_ext_zeroout
Change ext4_ext_zeroout to use sb_issue_zeroout instead of its
own approach to zero out extents.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-10-27 21:30:06 -04:00
Theodore Ts'o
58590b06d7 ext4: fix EOFBLOCKS_FL handling
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: "Theodore Ts'o" <tytso@mit.edu>
2010-10-27 21:23:12 -04:00
Linus Torvalds
09dc942c2a Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (40 commits)
  ext4: Adding error check after calling ext4_mb_regular_allocator()
  ext4: Fix dirtying of journalled buffers in data=journal mode
  ext4: re-inline ext4_rec_len_(to|from)_disk functions
  jbd2: Remove t_handle_lock from start_this_handle()
  jbd2: Change j_state_lock to be a rwlock_t
  jbd2: Use atomic variables to avoid taking t_handle_lock in jbd2_journal_stop
  ext4: Add mount options in superblock
  ext4: force block allocation on quota_off
  ext4: fix freeze deadlock under IO
  ext4: drop inode from orphan list if ext4_delete_inode() fails
  ext4: check to make make sure bd_dev is set before dereferencing it
  jbd2: Make barrier messages less scary
  ext4: don't print scary messages for allocation failures post-abort
  ext4: fix EFBIG edge case when writing to large non-extent file
  ext4: fix ext4_get_blocks references
  ext4: Always journal quota file modifications
  ext4: Fix potential memory leak in ext4_fill_super
  ext4: Don't error out the fs if the user tries to make a file too big
  ext4: allocate stripe-multiple IOs on stripe boundaries
  ext4: move aio completion after unwritten extent conversion
  ...

Fix up conflicts in fs/ext4/inode.c as per Ted.

Fix up xfs conflicts as per earlier xfs merge.
2010-08-07 13:03:53 -07:00
Theodore Ts'o
c398eda0e4 ext4: Pass line numbers to ext4_error() and friends
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:40 -04:00
Jiri Kosina
f1bbbb6912 Merge branch 'master' into for-next 2010-06-16 18:08:13 +02:00
Uwe Kleine-König
421f91d21a fix typos concerning "initiali[zs]e"
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-06-16 18:05:05 +02:00
Andi Kleen
5a0790c2c4 ext4: remove initialized but not read variables
No real bugs found, just removed some dead code.

Found by gcc 4.6's new warnings.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-14 13:28:03 -04:00
Theodore Ts'o
60e6679e28 ext4: Drop whitespace at end of lines
This patch was generated using:

#!/usr/bin/perl -i
while (<>) {
    s/[ 	]+$//;
    print;
}

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-05-17 07:00:00 -04:00
Dmitry Monakhov
0617b83fa2 ext4: restart ext4_ext_remove_space() after transaction restart
If i_data_sem was internally dropped due to transaction restart, it is
necessary to restart path look-up because extents tree was possibly
modified by ext4_get_block().

https://bugzilla.kernel.org/show_bug.cgi?id=15827

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: Jan Kara <jack@suse.cz>
2010-05-17 01:00:00 -04:00
Theodore Ts'o
786ec7915e ext4: Clear the EXT4_EOFBLOCKS_FL flag only when warranted
Dimitry Monakhov discovered an edge case where it was possible for the
EXT4_EOFBLOCKS_FL flag could get cleared unnecessarily.  This is true;
I have a test case that can be exercised via downloading and
decompressing the file:

wget ftp://ftp.kernel.org/pub/linux/kernel/people/tytso/ext4-testcases/eofblocks-fl-test-case.img.bz2
bunzip2 eofblocks-fl-test-case.img
dd if=/dev/zero of=eofblocks-fl-test-case.img bs=1k seek=17925 bs=1k count=1 conv=notrunc

However, triggering it in real life is highly unlikely since it
requires an extremely fragmented sparse file with a hole in exactly
the right place in the extent tree.  (It actually took quite a bit of
work to generate this test case.)  Still, it's nice to get even
extreme corner cases to be correct, so this patch makes sure that we
don't clear the EXT4_EOFBLOCKS_FL incorrectly even in this corner
case.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-05-17 00:00:00 -04:00