1
Commit Graph

147 Commits

Author SHA1 Message Date
Theodore Ts'o
89eeddf033 ext4: Define s_jnl_backup_type in superblock
This has been in use by e2fsprogs for a while; define it to keep the
super block fields in sync.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:04 -04:00
Theodore Ts'o
66e61a9e95 ext4: Once a day, printk file system error information to dmesg
This allows us to grab any file system error messages by scraping
/var/log/messages.  This will make it easy for us to do error analysis
across the very large number of machines as we deploy ext4 across the
fleet.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:04 -04:00
Theodore Ts'o
1c13d5c087 ext4: Save error information to the superblock for analysis
Save number of file system errors, and the time function name, line
number, block number, and inode number of the first and most recent
errors reported on the file system in the superblock.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:56:03 -04:00
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
Theodore Ts'o
60fd4da34d ext4: Cleanup ext4_check_dir_entry so __func__ is now implicit
Also start passing the line number to ext4_check_dir since we're going
to need it in upcoming patch.
    
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-07-27 11:54:40 -04:00
Theodore Ts'o
e29136f80e ext4: Enhance ext4_grp_locked_error() to take block and function numbers
Also use a macro definition so that __func__ and __LINE__ is implicit.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-29 12:54:28 -04:00
Theodore Ts'o
c67d859e39 ext4: clean up ext4_abort() so __func__ is now implicit
Use a macro definition for ext4_abort() to clean up the .c files a wee
bit.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-29 11:07:07 -04:00
Theodore Ts'o
4a9cdec73f ext4: Add new superblock fields reserved for the Next3 snapshot feature
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-29 11:00:23 -04:00
Christoph Hellwig
206f7ab4f4 ext4: remove vestiges of nobh support
The nobh option was only supported for writeback mode, but given that all
write paths actually create buffer heads it effectively was a no-op already.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-14 14:42:49 -04:00
Theodore Ts'o
a0375156ca ext4: Clean up s_dirt handling
We don't need to set s_dirt in most of the ext4 code when journaling
is enabled.  In ext3/4 some of the summary statistics for # of free
inodes, blocks, and directories are calculated from the per-block
group statistics when the file system is mounted or unmounted.  As a
result the superblock doesn't have to be updated, either via the
journal or by setting s_dirt.  There are a few exceptions, most
notably when resizing the file system, where the superblock needs to
be modified --- and in that case it should be done as a journalled
operation if possible, and s_dirt set only in no-journal mode.

This patch will optimize out some unneeded disk writes when using ext4
with a journal.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-06-11 23:14:04 -04:00
Christoph Hellwig
7ea8085910 drop unused dentry argument to ->fsync
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-27 22:05:02 -04:00
Frank Mayhar
14ece1028b ext4: Make fsync sync new parent directories in no-journal mode
Add a new ext4 state to tell us when a file has been newly created; use
that state in ext4_sync_file in no-journal mode to tell us when we need
to sync the parent directory as well as the inode and data itself.  This
fixes a problem in which a panic or power failure may lose the entire
file even when using fsync, since the parent directory entry is lost.

Addresses-Google-Bug: #2480057

Signed-off-by: Frank Mayhar <fmayhar@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-05-17 08:00:00 -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
Ben Hutchings
4d92dc0f00 ext4: Fix compat EXT4_IOC_ADD_GROUP
struct ext4_new_group_input needs to be converted because u64 has
only 32-bit alignment on some 32-bit architectures, notably i386.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-05-17 06:00:00 -04:00
Ben Hutchings
899ad0cea6 ext4: Conditionally define compat ioctl numbers
It is unnecessary, and in general impossible, to define the compat
ioctl numbers except when building the filesystem with CONFIG_COMPAT
defined.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-05-17 05:00:00 -04:00
Dmitry Monakhov
12e9b89200 ext4: Use bitops to read/modify i_flags in struct ext4_inode_info
At several places we modify EXT4_I(inode)->i_flags without holding
i_mutex (ext4_do_update_inode, ...). These modifications are racy and
we can lose updates to i_flags. So convert handling of i_flags to use
bitops which are atomic.

https://bugzilla.kernel.org/show_bug.cgi?id=15792

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-05-16 22:00:00 -04:00
Theodore Ts'o
24676da469 ext4: Convert calls of ext4_error() to EXT4_ERROR_INODE()
EXT4_ERROR_INODE() tends to provide better error information and in a
more consistent format.  Some errors were not even identifying the inode
or directory which was corrupted, which made them not very useful.

Addresses-Google-Bug: #2507977

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-05-16 21:00:00 -04:00
Theodore Ts'o
e35fd6609b ext4: Add new abstraction ext4_map_blocks() underneath ext4_get_blocks()
Jack up ext4_get_blocks() and add a new function, ext4_map_blocks()
which uses a much smaller structure, struct ext4_map_blocks which is
20 bytes, as opposed to a struct buffer_head, which nearly 5 times
bigger on an x86_64 machine.  By switching things to use
ext4_map_blocks(), we can save stack space by using ext4_map_blocks()
since we can avoid allocating a struct buffer_head on the stack.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-05-16 19:00:00 -04:00
Curt Wohlgemuth
8a57d9d61a ext4: check for a good block group before loading buddy pages
This adds a new field in ext4_group_info to cache the largest available
block range in a block group; and don't load the buddy pages until *after*
we've done a sanity check on the block group.

With large allocation requests (e.g., fallocate(), 8MiB) and relatively full
partitions, it's easy to have no block groups with a block extent large
enough to satisfy the input request length.  This currently causes the loop
during cr == 0 in ext4_mb_regular_allocator() to load the buddy bitmap pages
for EVERY block group.  That can be a lot of pages.  The patch below allows
us to call ext4_mb_good_group() BEFORE we load the buddy pages (although we
have check again after we lock the block group).

Addresses-Google-Bug: #2578108
Addresses-Google-Bug: #2704453

Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-05-16 15:00:00 -04:00
Linus Torvalds
9467c4fdd6 Merge branch 'write_inode2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'write_inode2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  pass writeback_control to ->write_inode
  make sure data is on disk before calling ->write_inode
2010-03-05 11:53:53 -08:00
Linus Torvalds
1f63b9c15b 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: (36 commits)
  ext4: fix up rb_root initializations to use RB_ROOT
  ext4: Code cleanup for EXT4_IOC_MOVE_EXT ioctl
  ext4: Fix the NULL reference in double_down_write_data_sem()
  ext4: Fix insertion point of extent in mext_insert_across_blocks()
  ext4: consolidate in_range() definitions
  ext4: cleanup to use ext4_grp_offs_to_block()
  ext4: cleanup to use ext4_group_first_block_no()
  ext4: Release page references acquired in ext4_da_block_invalidatepages
  ext4: Fix ext4_quota_write cross block boundary behaviour
  ext4: Convert BUG_ON checks to use ext4_error() instead
  ext4: Use direct_IO_no_locking in ext4 dio read
  ext4: use ext4_get_block_write in buffer write
  ext4: mechanical rename some of the direct I/O get_block's identifiers
  ext4: make "offset" consistent in ext4_check_dir_entry()
  ext4: Handle non empty on-disk orphan link
  ext4: explicitly remove inode from orphan list after failed direct io
  ext4: fix error handling in migrate
  ext4: deprecate obsoleted mount options
  ext4: Fix fencepost error in chosing choosing group vs file preallocation.
  jbd2: clean up an assertion in jbd2_journal_commit_transaction()
  ...
2010-03-05 10:47:00 -08:00
Christoph Hellwig
a9185b41a4 pass writeback_control to ->write_inode
This gives the filesystem more information about the writeback that
is happening.  Trond requested this for the NFS unstable write handling,
and other filesystems might benefit from this too by beeing able to
distinguish between the different callers in more detail.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-03-05 13:25:52 -05:00
Akinobu Mita
731eb1a03a ext4: consolidate in_range() definitions
There are duplicate macro definitions of in_range() in mballoc.h and
balloc.c.  This consolidates these two definitions into ext4.h, and
changes extents.c to use in_range() as well.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger@sun.com>
2010-03-03 23:55:01 -05:00
Frank Mayhar
273df556b6 ext4: Convert BUG_ON checks to use ext4_error() instead
Convert a bunch of BUG_ONs to emit a ext4_error() message and return
EIO.  This is a first pass and most notably does _not_ cover
mballoc.c, which is a morass of void functions.

Signed-off-by: Frank Mayhar <fmayhar@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-03-02 11:46:09 -05:00
Jiaying Zhang
744692dc05 ext4: use ext4_get_block_write in buffer write
Allocate uninitialized extent before ext4 buffer write and
convert the extent to initialized after io completes.
The purpose is to make sure an extent can only be marked
initialized after it has been written with new data so
we can safely drop the i_mutex lock in ext4 DIO read without
exposing stale data. This helps to improve multi-thread DIO
read performance on high-speed disks.

Skip the nobh and data=journal mount cases to make things simple for now.

Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-03-04 16:14:02 -05:00
Jiaying Zhang
c7064ef13b ext4: mechanical rename some of the direct I/O get_block's identifiers
This commit renames some of the direct I/O's block allocation flags,
variables, and functions introduced in Mingming's "Direct IO for holes
and fallocate" patches so that they can be used by ext4's buffered
write path as well.  Also changed the related function comments
accordingly to cover both direct write and buffered write cases.

Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-03-02 13:28:44 -05:00
Jiaying Zhang
c8d46e41bc ext4: Add flag to files with blocks intentionally past EOF
fallocate() may potentially instantiate blocks past EOF, depending
on the flags used when it is called.

e2fsck currently has a test for blocks past i_size, and it
sometimes trips up - noticeably on xfstests 013 which runs fsstress.

This patch from Jiayang does fix it up - it (along with
e2fsprogs updates and other patches recently from Aneesh) has
survived many fsstress runs in a row.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-02-24 09:52:53 -05:00
Tejun Heo
003cb608a2 percpu: add __percpu sparse annotations to fs
Add __percpu sparse annotations to fs.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors.  This patch doesn't affect normal builds.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-02-17 11:17:38 +09:00
Eric Sandeen
12062dddda ext4: move __func__ into a macro for ext4_warning, ext4_error
Just a pet peeve of mine; we had a mishash of calls with either __func__
or "function_name" and the latter tends to get out of sync.

I think it's easier to just hide the __func__ in a macro, and it'll
be consistent from then on.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-02-15 14:19:27 -05:00
Theodore Ts'o
f710b4b96b ext4: Reserve INCOMPAT_EA_INODE and INCOMPAT_DIRDATA feature codepoints
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-01-25 03:31:32 -05:00
Theodore Ts'o
19f5fb7ad6 ext4: Use bitops to read/modify EXT4_I(inode)->i_state
At several places we modify EXT4_I(inode)->i_state without holding
i_mutex (ext4_release_file, ext4_bmap, ext4_journalled_writepage,
ext4_do_update_inode, ...). These modifications are racy and we can
lose updates to i_state. So convert handling of i_state to use bitops
which are atomic.

Cc: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-01-24 14:34:07 -05:00
Aneesh Kumar K.V
1296cc85c2 ext4: Drop EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE flag
We should update reserve space if it is delalloc buffer
and that is indicated by EXT4_GET_BLOCKS_DELALLOC_RESERVE flag.
So use EXT4_GET_BLOCKS_DELALLOC_RESERVE in place of
EXT4_GET_BLOCKS_UPDATE_RESERVE_SPACE

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2010-01-15 01:27:59 -05:00
Aneesh Kumar K.V
5f634d064c ext4: Fix quota accounting error with fallocate
When we fallocate a region of the file which we had recently written,
and which is still in the page cache marked as delayed allocated blocks
we need to make sure we don't do the quota update on writepage path.
This is because the needed quota updated would have already be done
by fallocate.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
2010-01-25 04:00:31 -05:00
Theodore Ts'o
9d0be50230 ext4: Calculate metadata requirements more accurately
In the past, ext4_calc_metadata_amount(), and its sub-functions
ext4_ext_calc_metadata_amount() and ext4_indirect_calc_metadata_amount()
badly over-estimated the number of metadata blocks that might be
required for delayed allocation blocks.  This didn't matter as much
when functions which managed the reserved metadata blocks were more
aggressive about dropping reserved metadata blocks as delayed
allocation blocks were written, but unfortunately they were too
aggressive.  This was fixed in commit 0637c6f, but as a result the
over-estimation by ext4_calc_metadata_amount() would lead to reserving
2-3 times the number of pending delayed allocation blocks as
potentially required metadata blocks.  So if there are 1 megabytes of
blocks which have been not yet been allocation, up to 3 megabytes of
space would get reserved out of the user's quota and from the file
system free space pool until all of the inode's data blocks have been
allocated.

This commit addresses this problem by much more accurately estimating
the number of metadata blocks that will be required.  It will still
somewhat over-estimate the number of blocks needed, since it must make
a worst case estimate not knowing which physical blocks will be
needed, but it is much more accurate than before.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-01-01 02:41:30 -05:00
Dmitry Monakhov
a9e7f44720 ext4: Convert to generic reserved quota's space management.
This patch also fixes write vs chown race condition.

Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jan Kara <jack@suse.cz>
2009-12-23 13:33:55 +01:00
Theodore Ts'o
1f2acb6017 ext4: Add block validity check when truncating indirect block mapped inodes
Add checks to ext4_free_branches() to make sure a block number found
in an indirect block are valid before trying to free it.  If a bad
block number is found, stop freeing the indirect block immediately,
since the file system is corrupt and we will need to run fsck anyway.
This also avoids spamming the logs, and specifically avoids
driver-level "attempt to access beyond end of device" errors obscure
what is really going on.

If you get *really*, *really*, *really* unlucky, without this patch, a
supposed indirect block containing garbage might contain a reference
to a primary block group descriptor, in which case
ext4_free_branches() could end up zero'ing out a block group
descriptor block, and if then one of the block bitmaps for a block
group described by that bg descriptor block is not in memory, and is
read in by ext4_read_block_bitmap().  This function calls
ext4_valid_block_bitmap(), which assumes that bg_inode_table() was
validated at mount time and hasn't been modified since.  Since this
assumption is no longer valid, it's possible for the value
(ext4_inode_table(sb, desc) - group_first_block) to go negative, which
will cause ext4_find_next_zero_bit() to trigger a kernel GPF.

Addresses-Google-Bug: #2220436

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2010-01-22 17:40:42 -05:00
Eric Sandeen
a1de02dccf ext4: fix async i/o writes beyond 4GB to a sparse file
The "offset" member in ext4_io_end holds bytes, not blocks, so
ext4_lblk_t is wrong - and too small (u32).

This caused the async i/o writes to sparse files beyond 4GB to fail
when they wrapped around to 0.

Also fix up the type of arguments to ext4_convert_unwritten_extents(),
it gets ssize_t from ext4_end_aio_dio_nolock() and
ext4_ext_direct_IO().

Reported-by: Giel de Nijs <giel@vectorwise.com>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
2010-02-04 23:58:38 -05:00
Jan Kara
b436b9bef8 ext4: Wait for proper transaction commit on fsync
We cannot rely on buffer dirty bits during fsync because pdflush can come
before fsync is called and clear dirty bits without forcing a transaction
commit. What we do is that we track which transaction has last changed
the inode and which transaction last changed allocation and force it to
disk on fsync.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-12-08 23:51:10 -05:00
Theodore Ts'o
e6362609b6 ext4: call ext4_forget() from ext4_free_blocks()
Add the facility for ext4_forget() to be called from
ext4_free_blocks().  This simplifies the code in a large number of
places, and centralizes most of the work of calling ext4_forget() into
a single place.

Also fix a bug in the extents migration code; it wasn't calling
ext4_forget() when releasing the indirect blocks during the
conversion.  As a result, if the system cashed during or shortly after
the extents migration, and the released indirect blocks get reused as
data blocks, the journal replay would corrupt the data blocks.  With
this new patch, fixing this bug was as simple as adding the
EXT4_FREE_BLOCKS_FORGET flags to the call to ext4_free_blocks().

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
2009-11-23 07:17:05 -05:00
Theodore Ts'o
4433871130 ext4: fold ext4_free_blocks() and ext4_mb_free_blocks()
ext4_mb_free_blocks() is only called by ext4_free_blocks(), and the
latter function doesn't really do much.  So merge the two functions
together, such that ext4_free_blocks() is now found in
fs/ext4/mballoc.c.  This saves about 200 bytes of compiled text space.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-11-22 07:44:56 -05:00
Theodore Ts'o
d6797d14b1 ext4: move ext4_forget() to ext4_jbd2.c
The ext4_forget() function better belongs in ext4_jbd2.c.  This will
allow us to do some cleanup of the ext4_journal_revoke() and
ext4_journal_forget() functions, as well as giving us better error
reporting since we can report the caller of ext4_forget() when things
go wrong.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-11-22 20:52:12 -05:00
Eric Sandeen
5328e63531 ext4: make trim/discard optional (and off by default)
It is anticipated that when sb_issue_discard starts doing
real work on trim-capable devices, we may see issues.  Make
this mount-time optional, and default it to off until we know
that things are working out OK.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-11-19 14:25:42 -05:00
Mingming
5f5249507e ext4: skip conversion of uninit extents after direct IO if there isn't any
At the end of direct I/O operation, ext4_ext_direct_IO() always called
ext4_convert_unwritten_extents(), regardless of whether there were any
unwritten extents involved in the I/O or not.

This commit adds a state flag so that ext4_ext_direct_IO() only calls
ext4_convert_unwritten_extents() when necessary.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-11-10 10:48:04 -05:00
Linus Torvalds
d4da6c9ccf Revert "ext4: Remove journal_checksum mount option and enable it by default"
This reverts commit d0646f7b63, as
requested by Eric Sandeen.

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

Quoth Eric:

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

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

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

See

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

for all the gory details.

Requested-by: Eric Sandeen <sandeen@redhat.com>
Cc: Theodore Tso <tytso@mit.edu>
Cc: Alexey Fisher <bug-track@fisher-privat.net>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Mathias Burén <mathias.buren@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-11-02 10:15:27 -08:00
Theodore Ts'o
c1fccc0696 ext4: Fix time encoding with extra epoch bits
"Looking at ext4.h, I think the setting of extra time fields forgets to
mask the epoch bits so the epoch part overwrites nsec part. The second
change is only for coherency (2 -> EXT4_EPOCH_BITS)."

Thanks to Damien Guibouret for pointing out this problem.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-30 01:13:55 -04:00
Theodore Ts'o
296c355cd6 ext4: Use tracepoints for mb_history trace file
The /proc/fs/ext4/<dev>/mb_history was maintained manually, and had a
number of problems: it required a largish amount of memory to be
allocated for each ext4 filesystem, and the s_mb_history_lock
introduced a CPU contention problem.  

By ripping out the mb_history code and replacing it with ftrace
tracepoints, and we get more functionality: timestamps, event
filtering, the ability to correlate mballoc history with other ext4
tracepoints, etc.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-30 00:32:42 -04:00
Mingming Cao
8d5d02e6b1 ext4: async direct IO for holes and fallocate support
For async direct IO that covers holes or fallocate, the end_io
callback function now queued the convertion work on workqueue but
don't flush the work rightaway as it might take too long to afford.

But when fsync is called after all the data is completed, user expects
the metadata also being updated before fsync returns.

Thus we need to flush the conversion work when fsync() is called.
This patch keep track of a listed of completed async direct io that
has a work queued on workqueue.  When fsync() is called, it will go
through the list and do the conversion.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
2009-09-28 15:48:29 -04:00
Mingming Cao
4c0425ff68 ext4: Use end_io callback to avoid direct I/O fallback to buffered I/O
Currently the DIO VFS code passes create = 0 when writing to the
middle of file.  It does this to avoid block allocation for holes, so
as not to expose stale data out when there is a parallel buffered read
(which does not hold the i_mutex lock).  Direct I/O writes into holes
falls back to buffered IO for this reason.

Since preallocated extents are treated as holes when doing a
get_block() look up (buffer is not mapped), direct IO over fallocate
also falls back to buffered IO.  Thus ext4 actually silently falls
back to buffered IO in above two cases, which is undesirable.

To fix this, this patch creates unitialized extents when a direct I/O
write into holes in sparse files, and registering an end_io callback which
converts the uninitialized extent to an initialized extent after the
I/O is completed.

Singed-Off-By: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-28 15:48:41 -04:00
Mingming Cao
0031462b5b ext4: Split uninitialized extents for direct I/O
When writing into an unitialized extent via direct I/O, and the direct
I/O doesn't exactly cover the unitialized extent, split the extent
into uninitialized and initialized extents before submitting the I/O.
This avoids needing to deal with an ENOSPC error in the end_io
callback that gets used for direct I/O.

When the IO is complete, the written extent will be marked as initialized.

Singed-Off-By: Mingming Cao <cmm@us.ibm.com> 
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-28 15:49:08 -04:00
Theodore Ts'o
55138e0bc2 ext4: Adjust ext4_da_writepages() to write out larger contiguous chunks
Work around problems in the writeback code to force out writebacks in
larger chunks than just 4mb, which is just too small.  This also works
around limitations in the ext4 block allocator, which can't allocate
more than 2048 blocks at a time.  So we need to defeat the round-robin
characteristics of the writeback code and try to write out as many
blocks in one inode before allowing the writeback code to move on to
another inode.  We add a a new per-filesystem tunable,
max_writeback_mb_bump, which caps this to a default of 128mb per
inode.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
2009-09-29 13:31:31 -04:00