Commit Graph

393 Commits

Author SHA1 Message Date
Aditya Kali
5356f2615c ext4: attempt to fix race in bigalloc code path
Currently, there exists a race between delayed allocated writes and
the writeback when bigalloc feature is in use. The race was because we
wanted to determine what blocks in a cluster are under delayed
allocation and we were using buffer_delayed(bh) check for it. But, the
writeback codepath clears this bit without any synchronization which
resulted in a race and an ext4 warning similar to:

EXT4-fs (ram1): ext4_da_update_reserve_space: ino 13, used 1 with only 0
		reserved data blocks

The race existed in two places.
(1) between ext4_find_delalloc_range() and ext4_map_blocks() when called from
    writeback code path.
(2) between ext4_find_delalloc_range() and ext4_da_get_block_prep() (where
    buffer_delayed(bh) is set.

To fix (1), this patch introduces a new buffer_head state bit -
BH_Da_Mapped.  This bit is set under the protection of
EXT4_I(inode)->i_data_sem when we have actually mapped the delayed
allocated blocks during the writeout time. We can now reliably check
for this bit inside ext4_find_delalloc_range() to determine whether
the reservation for the blocks have already been claimed or not.

To fix (2), it was necessary to set buffer_delay(bh) under the
protection of i_data_sem.  So, I extracted the very beginning of
ext4_map_blocks into a new function - ext4_da_map_blocks() - and
performed the required setting of bh_delay bit and the quota
reservation under the protection of i_data_sem.  These two fixes makes
the checking of buffer_delay(bh) and buffer_da_mapped(bh) consistent,
thus removing the race.

Tested: I was able to reproduce the problem by running 'dd' and
'fsync' in parallel. Also, xfstests sometimes used to reproduce this
race. After the fix both my test and xfstests were successful and no
race (warning message) was observed.

Google-Bug-Id: 4997027

Signed-off-by: Aditya Kali <adityakali@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-09 19:20:51 -04:00
Aditya Kali
d8990240d8 ext4: add some tracepoints in ext4/extents.c
This patch adds some tracepoints in ext4/extents.c and updates a tracepoint in
ext4/inode.c.

Tested: Built and ran the kernel and verified that these tracepoints work.
Also ran xfstests.

Signed-off-by: Aditya Kali <adityakali@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-09 19:18:51 -04:00
Theodore Ts'o
df55c99dc8 ext4: rename ext4_has_free_blocks() to ext4_has_free_clusters()
Rename the function so it is more clear what is going on.  Also rename
the various variables so it's clearer what's happening.

Also fix a missing blocks to cluster conversion when reading the
number of reserved blocks for root.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-09 19:16:51 -04:00
Theodore Ts'o
e7d5f3156e ext4: rename ext4_claim_free_blocks() to ext4_claim_free_clusters()
This function really claims a number of free clusters, not blocks, so
rename it so it's clearer what's going on.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-09 19:14:51 -04:00
Theodore Ts'o
5dee54372c ext4: rename ext4_count_free_blocks() to ext4_count_free_clusters()
This function really counts the free clusters reported in the block
group descriptors, so rename it to reduce confusion.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-09 19:10:51 -04:00
Aditya Kali
7b415bf60f ext4: Fix bigalloc quota accounting and i_blocks value
With bigalloc changes, the i_blocks value was not correctly set (it was still
set to number of blocks being used, but in case of bigalloc, we want i_blocks
to represent the number of clusters being used). Since the quota subsystem sets
the i_blocks value, this patch fixes the quota accounting and makes sure that
the i_blocks value is set correctly.

Signed-off-by: Aditya Kali <adityakali@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-09 19:04:51 -04:00
Theodore Ts'o
5704265188 ext4: convert s_{dirty,free}blocks_counter to s_{dirty,free}clusters_counter
Convert the percpu counters s_dirtyblocks_counter and
s_freeblocks_counter in struct ext4_super_info to be
s_dirtyclusters_counter and s_freeclusters_counter.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-09 18:56:51 -04:00
Theodore Ts'o
bab08ab964 ext4: enforce bigalloc restrictions (e.g., no online resizing, etc.)
At least initially if the bigalloc feature is enabled, we will not
support non-extent mapped inodes, online resizing, online defrag, or
the FITRIM ioctl.  This simplifies the initial implementation.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-09 18:36:51 -04:00
Allison Henderson
02fac1297e ext4: fix partial page writes
While running extended fsx tests to verify the preceeding patches,
a similar bug was also found in the write operation

When ever a write operation begins or ends in a hole,
or extends EOF, the partial page contained in the hole
or beyond EOF needs to be zeroed out.

To correct this the new ext4_discard_partial_page_buffers_no_lock
routine is used to zero out the partial page, but only for buffer
heads that are already unmapped.

Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-06 21:53:01 -04:00
Theodore Ts'o
decbd919f4 ext4: only call ext4_jbd2_file_inode when an inode has been extended
In delayed allocation mode, it's important to only call
ext4_jbd2_file_inode when the file has been extended.  This is
necessary to avoid a race which first got introduced in commit
678aaf481, but which was made much more common with the introduction
of the "punch hole" functionality.  (Especially when dioread_nolock
was enabled; when I could reliably reproduce this problem with
xfstests #74.)

The race is this: If while trying to writeback a delayed allocation
inode, there is a need to map delalloc blocks, and we run out of space
in the journal, *and* at the same time the inode is already on the
committing transaction's t_inode_list (because for example while doing
the punch hole operation, ext4_jbd2_file_inode() is called), then the
commit operation will wait for the inode to finish all of its pending
writebacks by calling filemap_fdatawait(), but since that inode has
one or more pages with the PageWriteback flag set, the commit
operation will wait forever, and the so the writeback of the inode can
never take place, and the kjournald thread and the writeback thread
end up waiting for each other --- forever.

It's important at this point to recall why an inode is placed on the
t_inode_list; it is to provide the data=ordered guarantees that we
don't end up exposing stale data.  In the case where we are truncating
or punching a hole in the inode, there is no possibility that stale
data could be exposed in the first place, so we don't need to put the
inode on the t_inode_list!

The right long-term fix is to get rid of data=ordered mode altogether,
and only update the extent tree or indirect blocks after the data has
been written.  Until then, this change will also avoid some
unnecessary waiting in the commit operation.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Allison Henderson <achender@linux.vnet.ibm.com>
Cc: Jan Kara <jack@suse.cz>
2011-09-06 02:37:06 -04:00
Allison Henderson
4e96b2dbbf ext4: Add new ext4_discard_partial_page_buffers routines
This patch adds two new routines: ext4_discard_partial_page_buffers
and ext4_discard_partial_page_buffers_no_lock.

The ext4_discard_partial_page_buffers routine is a wrapper
function to ext4_discard_partial_page_buffers_no_lock.
The wrapper function locks the page and passes it to
ext4_discard_partial_page_buffers_no_lock.
Calling functions that already have the page locked can call
ext4_discard_partial_page_buffers_no_lock directly.

The ext4_discard_partial_page_buffers_no_lock function
zeros a specified range in a page, and unmaps the
corresponding buffer heads.  Only block aligned regions of the
page will have their buffer heads unmapped.  Unblock aligned regions
will be mapped if needed so that they can be updated with the
partial zero out.  This function is meant to
be used to update a page and its buffer heads to be zeroed
and unmapped when the corresponding blocks have been released
or will be released.

This routine is used in the following scenarios:
* A hole is punched and the non page aligned regions
  of the head and tail of the hole need to be discarded

* The file is truncated and the partial page beyond EOF needs
  to be discarded

* The end of a hole is in the same page as EOF.  After the
  page is flushed, the partial page beyond EOF needs to be
  discarded.

* A write operation begins or ends inside a hole and the partial
  page appearing before or after the write needs to be discarded

* A write operation extends EOF and the partial page beyond EOF
  needs to be discarded

This function takes a flag EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED
which is used when a write operation begins or ends in a hole.
When the EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED flag is used, only
buffer heads that are already unmapped will have the corresponding
regions of the page zeroed.

Signed-off-by: Allison Henderson <achender@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-09-03 11:51:09 -04:00
Theodore Ts'o
84ebd79561 ext4: fake direct I/O mode for data=journal
Currently attempts to open a file with O_DIRECT in data=journal mode
causes the open to fail with -EINVAL.  This makes it very hard to test
data=journal mode.  So we will let the open succeed, but then always
fall back to O_DSYNC buffered writes.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-08-31 11:56:51 -04:00
Jiaying Zhang
8c0bec2151 ext4: remove i_mutex lock in ext4_evict_inode to fix lockdep complaining
The i_mutex lock and flush_completed_IO() added by commit 2581fdc810
in ext4_evict_inode() causes lockdep complaining about potential
deadlock in several places.  In most/all of these LOCKDEP complaints
it looks like it's a false positive, since many of the potential
circular locking cases can't take place by the time the
ext4_evict_inode() is called; but since at the very least it may mask
real problems, we need to address this.

This change removes the flush_completed_IO() and i_mutex lock in
ext4_evict_inode().  Instead, we take a different approach to resolve
the software lockup that commit 2581fdc810 intends to fix.  Rather
than having ext4-dio-unwritten thread wait for grabing the i_mutex
lock of an inode, we use mutex_trylock() instead, and simply requeue
the work item if we fail to grab the inode's i_mutex lock.

This should speed up work queue processing in general and also
prevents the following deadlock scenario: During page fault,
shrink_icache_memory is called that in turn evicts another inode B.
Inode B has some pending io_end work so it calls ext4_ioend_wait()
that waits for inode B's i_ioend_count to become zero.  However, inode
B's ioend work was queued behind some of inode A's ioend work on the
same cpu's ext4-dio-unwritten workqueue.  As the ext4-dio-unwritten
thread on that cpu is processing inode A's ioend work, it tries to
grab inode A's i_mutex lock.  Since the i_mutex lock of inode A is
still hold before the page fault happened, we enter a deadlock.

Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-08-31 11:50:51 -04:00
Theodore Ts'o
9dd75f1f1a ext4: fix nomblk_io_submit option so it correctly converts uninit blocks
Bug discovered by Jan Kara:

Finally, commit 1449032be1 returned back
the old IO submission code but apparently it forgot to return the old
handling of uninitialized buffers so we unconditionnaly call
block_write_full_page() without specifying end_io function. So AFAICS
we never convert unwritten extents to written in some cases. For
example when I mount the fs as: mount -t ext4 -o
nomblk_io_submit,dioread_nolock /dev/ubdb /mnt and do
        int fd = open(argv[1], O_RDWR | O_CREAT | O_TRUNC, 0600);
        char buf[1024];
        memset(buf, 'a', sizeof(buf));
        fallocate(fd, 0, 0, 16384);
        write(fd, buf, sizeof(buf));

I get a file full of zeros (after remounting the filesystem so that
pagecache is dropped) instead of seeing the first KB contain 'a's.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
2011-08-13 12:58:21 -04:00
Tao Ma
32c80b32c0 ext4: Resolve the hang of direct i/o read in handling EXT4_IO_END_UNWRITTEN.
EXT4_IO_END_UNWRITTEN flag set and the increase of i_aiodio_unwritten
should be done simultaneously since ext4_end_io_nolock always clear
the flag and decrease the counter in the same time.

We don't increase i_aiodio_unwritten when setting
EXT4_IO_END_UNWRITTEN so it will go nagative and causes some process
to wait forever.

Part of the patch came from Eric in his e-mail, but it doesn't fix the
problem met by Michael actually.

http://marc.info/?l=linux-ext4&m=131316851417460&w=2

Reported-and-Tested-by: Michael Tokarev<mjt@tls.msk.ru>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
2011-08-13 12:30:59 -04:00
Jiaying Zhang
2581fdc810 ext4: call ext4_ioend_wait and ext4_flush_completed_IO in ext4_evict_inode
Flush inode's i_completed_io_list before calling ext4_io_wait to
prevent the following deadlock scenario: A page fault happens while
some process is writing inode A. During page fault,
shrink_icache_memory is called that in turn evicts another inode
B. Inode B has some pending io_end work so it calls ext4_ioend_wait()
that waits for inode B's i_ioend_count to become zero. However, inode
B's ioend work was queued behind some of inode A's ioend work on the
same cpu's ext4-dio-unwritten workqueue. As the ext4-dio-unwritten
thread on that cpu is processing inode A's ioend work, it tries to
grab inode A's i_mutex lock. Since the i_mutex lock of inode A is
still hold before the page fault happened, we enter a deadlock.

Also moves ext4_flush_completed_IO and ext4_ioend_wait from
ext4_destroy_inode() to ext4_evict_inode(). During inode deleteion,
ext4_evict_inode() is called before ext4_destroy_inode() and in
ext4_evict_inode(), we may call ext4_truncate() without holding
i_mutex lock. As a result, there is a race between flush_completed_IO
that is called from ext4_ext_truncate() and ext4_end_io_work, which
may cause corruption on an io_end structure. This change moves
ext4_flush_completed_IO and ext4_ioend_wait from ext4_destroy_inode()
to ext4_evict_inode() to resolve the race between ext4_truncate() and
ext4_end_io_work during inode deletion.

Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
2011-08-13 12:17:13 -04:00
Curt Wohlgemuth
441c850857 ext4: Fix ext4_should_writeback_data() for no-journal mode
ext4_should_writeback_data() had an incorrect sequence of
tests to determine if it should return 0 or 1: in
particular, even in no-journal mode, 0 was being returned
for a non-regular-file inode.

This meant that, in non-journal mode, we would use
ext4_journalled_aops for directories, symlinks, and other
non-regular files.  However, calling journalled aop
callbacks when there is no valid handle, can cause problems.

This would cause a kernel crash with Jan Kara's commit
2d859db3e4 ("ext4: fix data corruption in inodes with
journalled data"), because we now dereference 'handle' in
ext4_journalled_write_end().

I also added BUG_ONs to check for a valid handle in the
obviously journal-only aops callbacks.

I tested this running xfstests with a scratch device in
these modes:

   - no-journal
   - data=ordered
   - data=writeback
   - data=journal

All work fine; the data=journal run has many failures and a
crash in xfstests 074, but this is no different from a
vanilla kernel.

Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
2011-08-13 11:25:18 -04:00
Linus Torvalds
60ad446682 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: (60 commits)
  ext4: prevent memory leaks from ext4_mb_init_backend() on error path
  ext4: use EXT4_BAD_INO for buddy cache to avoid colliding with valid inode #
  ext4: use ext4_msg() instead of printk in mballoc
  ext4: use ext4_kvzalloc()/ext4_kvmalloc() for s_group_desc and s_group_info
  ext4: introduce ext4_kvmalloc(), ext4_kzalloc(), and ext4_kvfree()
  ext4: use the correct error exit path in ext4_init_inode_table()
  ext4: add missing kfree() on error return path in add_new_gdb()
  ext4: change umode_t in tracepoint headers to be an explicit __u16
  ext4: fix races in ext4_sync_parent()
  ext4: Fix overflow caused by missing cast in ext4_fallocate()
  ext4: add action of moving index in ext4_ext_rm_idx for Punch Hole
  ext4: simplify parameters of reserve_backup_gdb()
  ext4: simplify parameters of add_new_gdb()
  ext4: remove lock_buffer in bclean() and setup_new_group_blocks()
  ext4: simplify journal handling in setup_new_group_blocks()
  ext4: let setup_new_group_blocks() set multiple bits at a time
  ext4: fix a typo in ext4_group_extend()
  ext4: let ext4_group_add_blocks() handle 0 blocks quickly
  ext4: let ext4_group_add_blocks() return an error code
  ext4: rename ext4_add_groupblocks() to ext4_group_add_blocks()
  ...

Fix up conflict in fs/ext4/inode.c: commit aacfc19c62 ("fs: simplify
the blockdev_direct_IO prototype") had changed the ext4_ind_direct_IO()
function for the new simplified calling convention, while commit
dae1e52cb1 ("ext4: move ext4_ind_* functions from inode.c to
indirect.c") moved the function to another file.
2011-08-01 13:56:03 -10:00
Linus Torvalds
f01ef569cd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/writeback: (27 commits)
  mm: properly reflect task dirty limits in dirty_exceeded logic
  writeback: don't busy retry writeback on new/freeing inodes
  writeback: scale IO chunk size up to half device bandwidth
  writeback: trace global_dirty_state
  writeback: introduce max-pause and pass-good dirty limits
  writeback: introduce smoothed global dirty limit
  writeback: consolidate variable names in balance_dirty_pages()
  writeback: show bdi write bandwidth in debugfs
  writeback: bdi write bandwidth estimation
  writeback: account per-bdi accumulated written pages
  writeback: make writeback_control.nr_to_write straight
  writeback: skip tmpfs early in balance_dirty_pages_ratelimited_nr()
  writeback: trace event writeback_queue_io
  writeback: trace event writeback_single_inode
  writeback: remove .nonblocking and .encountered_congestion
  writeback: remove writeback_control.more_io
  writeback: skip balance_dirty_pages() for in-memory fs
  writeback: add bdi_dirty_limit() kernel-doc
  writeback: avoid extra sync work at enqueue time
  writeback: elevate queue_io() into wb_writeback()
  ...

Fix up trivial conflicts in fs/fs-writeback.c and mm/filemap.c
2011-07-26 10:39:54 -07:00
Jan Kara
2d859db3e4 ext4: fix data corruption in inodes with journalled data
When journalling data for an inode (either because it is a symlink or
because the filesystem is mounted in data=journal mode), ext4_evict_inode()
can discard unwritten data by calling truncate_inode_pages(). This is
because we don't mark the buffer / page dirty when journalling data but only
add the buffer to the running transaction and thus mm does not know there
are still unwritten data.

Fix the problem by carefully tracking transaction containing inode's data,
committing this transaction, and writing uncheckpointed buffers when inode
should be reaped.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-07-26 09:07:11 -04:00
Christoph Hellwig
72c5052ddc fs: move inode_dio_done to the end_io handler
For filesystems that delay their end_io processing we should keep our
i_dio_count until the the processing is done.  Enable this by moving
the inode_dio_done call to the end_io handler if one exist.  Note that
the actual move to the workqueue for ext4 and XFS is not done in
this patch yet, but left to the filesystem maintainers.  At least
for XFS it's not needed yet either as XFS has an internal equivalent
to i_dio_count.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:50 -04:00
Christoph Hellwig
aacfc19c62 fs: simplify the blockdev_direct_IO prototype
Simple filesystems always pass inode->i_sb_bdev as the block device
argument, and never need a end_io handler.  Let's simply things for
them and for my grepping activity by dropping these arguments.  The
only thing not falling into that scheme is ext4, which passes and
end_io handler without needing special flags (yet), but given how
messy the direct I/O code there is use of __blockdev_direct_IO
in one instead of two out of three cases isn't going to make a large
difference anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:49 -04:00
Christoph Hellwig
562c72aa57 fs: move inode_dio_wait calls into ->setattr
Let filesystems handle waiting for direct I/O requests themselves instead
of doing it beforehand.  This means filesystem-specific locks to prevent
new dio referenes from appearing can be held.  This is important to allow
generalizing i_dio_count to non-DIO_LOCKING filesystems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:47 -04:00
Jan Kara
9ea7df534e ext4: Rewrite ext4_page_mkwrite() to use generic helpers
Rewrite ext4_page_mkwrite() to use __block_page_mkwrite() helper. This
removes the need of using i_alloc_sem to avoid races with truncate which
seems to be the wrong locking order according to lock ordering documented in
mm/rmap.c. Also calling ext4_da_write_begin() as used by the old code seems to
be problematic because we can decide to flush delay-allocated blocks which
will acquire s_umount semaphore - again creating unpleasant lock dependency
if not directly a deadlock.

Also add a check for frozen filesystem so that we don't busyloop in page fault
when the filesystem is frozen.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:45 -04:00
Amir Goldstein
dae1e52cb1 ext4: move ext4_ind_* functions from inode.c to indirect.c
This patch moves functions from inode.c to indirect.c.
The moved functions are ext4_ind_* functions and their helpers.
Functions called from inode.c are declared extern.

Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-27 19:40:50 -04:00
Theodore Ts'o
9f125d641b ext4: move common truncate functions to header file
Move two functions that will be needed by the indirect functions to be
moved to indirect.c as well as inode.c to truncate.h as inline
functions, so that we can avoid having duplicate copies of the
function (which can be a maintenance problem) without having to expose
them as globally functions.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-27 19:16:04 -04:00
Theodore Ts'o
1f7d1e7741 ext4: move __ext4_check_blockref to block_validity.c
In preparation for moving the indirect functions to a separate file,
move __ext4_check_blockref() to block_validity.c and rename it to
ext4_check_blockref() which is exported as globally visible function.

Also, rename the cpp macro ext4_check_inode_blockref() to
ext4_ind_check_inode(), to make it clear that it is only valid for use
with non-extent mapped inodes.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-27 19:16:02 -04:00
Amir Goldstein
8bb2b24712 ext4: rename ext4_indirect_* funcs to ext4_ind_*
We are going to move all ext4_ind_* functions to indirect.c.
Before we do that, let's rename 2 functions called ext4_indirect_*
to ext4_ind_*, to keep to the naming convention.

Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-27 17:10:28 -04:00
Amir Goldstein
ff9893dc8a ext4: split ext4_ind_truncate from ext4_truncate
We are about to move all indirect inode functions to a new file.
Before we do that, let's split ext4_ind_truncate() out of ext4_truncate()
leaving only generic code in the latter, so we will be able to move
ext4_ind_truncate() to the new file.

Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-27 16:36:31 -04:00
Wu Fengguang
6e6938b6d3 writeback: introduce .tagged_writepages for the WB_SYNC_NONE sync stage
sync(2) is performed in two stages: the WB_SYNC_NONE sync and the
WB_SYNC_ALL sync. Identify the first stage with .tagged_writepages and
do livelock prevention for it, too.

Jan's commit f446daaea9 ("mm: implement writeback livelock avoidance
using page tagging") is a partial fix in that it only fixed the
WB_SYNC_ALL phase livelock.

Although ext4 is tested to no longer livelock with commit f446daaea9,
it may due to some "redirty_tail() after pages_skipped" effect which
is by no means a guarantee for _all_ the file systems.

Note that writeback_inodes_sb() is called by not only sync(), they are
treated the same because the other callers also need livelock prevention.

Impact:  It changes the order in which pages/inodes are synced to disk.
Now in the WB_SYNC_NONE stage, it won't proceed to write the next inode
until finished with the current inode.

Acked-by: Jan Kara <jack@suse.cz>
CC: Dave Chinner <david@fromorbit.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2011-06-08 08:25:20 +08:00
Lukas Czerner
a9c667f8f0 ext4: fixed tracepoints cleanup
While creating fixed tracepoints for ext3, basically by porting them
from ext4, I found a lot of useless retyping, wrong type usage, useless
variable passing and other inconsistencies in the ext4 fixed tracepoint
code.

This patch cleans the fixed tracepoint code for ext4 and also simplify
some of them.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-06-06 09:51:52 -04:00
Christoph Hellwig
aa38572954 fs: pass exact type of data dirties to ->dirty_inode
Tell the filesystem if we just updated timestamp (I_DIRTY_SYNC) or
anything else, so that the filesystem can track internally if it
needs to push out a transaction for fdatasync or not.

This is just the prototype change with no user for it yet.  I plan
to push large XFS changes for the next merge window, and getting
this trivial infrastructure in this window would help a lot to avoid
tree interdependencies.

Also remove incorrect comments that ->dirty_inode can't block.  That
has been changed a long time ago, and many implementations rely on it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-27 07:04:40 -04:00
Jan Kara
ae24f28d39 ext4: Convert ext4 to new truncate calling convention
Trivial conversion.  Fixup one error handling case calling vmtruncate()
and remove ->truncate callback. We also fix a bug that IS_IMMUTABLE and
IS_APPEND files could not be truncated during failed writes. In fact, the
test can be completely removed as upper layers do necessary permission
checks for truncate in do_sys_[f]truncate() and may_open() anyway.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-25 17:39:48 -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
308488518d ext4: add new function ext4_block_zero_page_range()
This patch modifies the existing ext4_block_truncate_page() function
which was used by the truncate code path, and which zeroes out block
unaligned data, by adding a new length parameter, and renames it to
ext4_block_zero_page_rage().  This function can now be used to zero out the
head of a block, the tail of a block, or the middle
of a block.

The ext4_block_truncate_page() function is now a wrapper to
ext4_block_zero_page_range().

[ext4 punch hole patch series 2/5 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 07:41:32 -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
Theodore Ts'o
072bd7ea74 ext4: use truncate_setsize() unconditionally
In commit c8d46e41 (ext4: Add flag to files with blocks intentionally
past EOF), if the EOFBLOCKS_FL flag is set, we call ext4_truncate()
before calling vmtruncate().  This caused any allocated but unwritten
blocks created by calling fallocate() with the FALLOC_FL_KEEP_SIZE
flag to be dropped.  This was done to make to make sure that
EOFBLOCKS_FL would not be cleared while still leaving blocks past
i_size allocated.  This was not necessary, since ext4_truncate()
guarantees that blocks past i_size will be dropped, even in the case
where truncate() has increased i_size before calling ext4_truncate().

So fix this by removing the EOFBLOCKS_FL special case treatment in
ext4_setattr().  In addition, use truncate_setsize() followed by a
call to ext4_truncate() instead of using vmtruncate().  This is more
efficient since it skips the call to inode_newsize_ok(), which has
been checked already by inode_change_ok().  This is also in a win in
the case where EOFBLOCKS_FL is set since it avoids calling
ext4_truncate() twice.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-23 15:13:02 -04:00
Darrick J. Wong
0e499890c1 ext4: wait for writeback to complete while making pages writable
In order to stabilize pages during disk writes, ext4_page_mkwrite must
wait for writeback operations to complete before making a page
writable.  Furthermore, the function must return locked pages, and
recheck the writeback status if the page lock is ever dropped.  The
"someone could wander in" part of this patch was suggested by Chris
Mason.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-18 13:55:20 -04:00
Darrick J. Wong
7cb1a5351d ext4: clean up some wait_on_page_writeback calls
wait_on_page_writeback already checks the writeback bit, so callers of it
needn't do that test.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-18 13:53:20 -04:00
Tao Ma
00d098822f ext4: use s_inodes_per_block directly in __ext4_get_inode_loc
In __ext4_get_inode_loc, we calculate inodes_per_block every time by
EXT4_BLOCK_SIZE(sb) / EXT4_INODE_SIZE(sb).  AFAICS, this function is a
hot path for ext4, so we'd better use s_inodes_per_block directly
instead of calculating every time.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-05-09 10:26:41 -04:00
Linus Torvalds
a97b52022a 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:
  ext4: fix data corruption regression by reverting commit 6de9843dab
  ext4: Allow indirect-block file to grow the file size to max file size
  ext4: allow an active handle to be started when freezing
  ext4: sync the directory inode in ext4_sync_parent()
  ext4: init timer earlier to avoid a kernel panic in __save_error_info
  jbd2: fix potential memory leak on transaction commit
  ext4: fix a double free in ext4_register_li_request
  ext4: fix credits computing for indirect mapped files
  ext4: remove unnecessary [cm]time update of quota file
  jbd2: move bdget out of critical section
2011-04-11 15:45:47 -07:00
Theodore Ts'o
c820563602 ext4: fix data corruption regression by reverting commit 6de9843dab
Revert commit 6de9843dab, since it
caused a data corruption regression with BitTorrent downloads.  Thanks
to Damien for discovering and bisecting to find the problem commit.

https://bugzilla.kernel.org/show_bug.cgi?id=32972

Reported-by: Damien Grassart <damien@grassart.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-04-10 22:30:07 -04:00
Kazuya Mio
f80da1e70f ext4: Allow indirect-block file to grow the file size to max file size
We can create 4402345721856 byte file with indirect block mapping.
However, if we grow an indirect-block file to the size with ftruncate(),
we can see an ext4 warning. The following patch fixes this problem.

How to reproduce:
# dd if=/dev/zero of=/mnt/mp1/hoge bs=1 count=0 seek=4402345721856
0+0 records in
0+0 records out
0 bytes (0 B) copied, 0.000221428 s, 0.0 kB/s
# tail -n 1 /var/log/messages
Nov 25 15:10:27 test kernel: EXT4-fs warning (device sda8): ext4_block_to_path:345: block 1074791436 > max in inode 12

Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-04-10 22:06:36 -04:00
Yongqiang Yang
5b41395fcc ext4: fix credits computing for indirect mapped files
When writing a contiguous set of blocks, two indirect blocks could be
needed depending on how the blocks are aligned, so we need to increase
the number of credits needed by one.

[ Also fixed a another bug which could further underestimate the
  number of journal credits needed by 1; the code was using integer
  division instead of DIV_ROUND_UP() -- tytso]

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@kernel.org
2011-04-04 15:40:24 -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
Feng Tang
6de9843dab ext4: remove redundant set_buffer_mapped() in ext4_da_get_block_prep()
The map_bh() call will have already set the buffer_head to mapped.

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-03-23 14:05:03 -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
Amir Goldstein
d67d121834 ext4: handle errors in ext4_clear_blocks()
Checking return code from ext4_journal_get_write_access() is important
with snapshots, because this function invokes COW, so may return new
errors, such as ENOSPC.

ext4_clear_blocks() now returns < 0 for fatal errors, in which case,
ext4_free_data() is aborted.

Signed-off-by: Amir Goldstein <amir73il@users.sf.net>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2011-03-20 22:59:02 -04:00
Jens Axboe
7eaceaccab block: remove per-queue plugging
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:52:07 +01:00