Before metadata is written to disk, it is updated to reflect that writeout
has begun.  Once this update is done, the block must be cow'd before it
can be modified again.

This update was originally synchronized by using a per-fs spinlock.  Today
the buffers for the metadata blocks are locked before writeout begins,
and everyone that tests the flag has the buffer locked as well.

So, the per-fs spinlock (called hash_lock for no good reason) is no
longer required.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

extent_io.c has debugging code to report and free leaked extent_state
and extent_buffer objects at rmmod time.  This helps track down
leaks and it saves you from rebooting just to properly remove the
kmem_cache object.

But, the code runs under a fairly expensive spinlock and the checks to
see if it is currently enabled are not entirely consistent.  Some use
#ifdef and some #if.

This changes everything to #if and disables the leak checking.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When a block goes through cow, we update the reference counts of
everything that block points to.  The internal pointers of the block
can be in just about any order, and it is likely to have clusters of
things that are close together and clusters of things that are not.

To help reduce the seeks that come with updating all of these reference
counts, sort them by byte number before actual updates are done.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Tracing shows the delay between when an async thread goes to sleep
and when more work is added is often very short.  This commit adds
a little bit of delay and extra checking to the code right before
we schedule out.

It allows more work to be added to the worker
without requiring notifications from other procs.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Add call to LSM security initialization and save
resulting security xattr for new inodes.

Add xattr support to symlink inode ops.

Set inode->i_op for existing special files.
Signed-off-by: Njim owens <jowens@hp.com>

This patch adds a menu entry to kconfig to enable acls for btrfs.
This allows you to enable FS_POSIX_ACL at kernel compile time.

(updated by Jeff Mahoney to make the changes in fs/btrfs/Kconfig instead)
Signed-off-by: NChristian Hesse <mail@earthworm.de>
Signed-off-by: NJeff Mahoney <jeffm@suse.com>

The async bio submission thread was missing some bios that were
added after it had decided there was no work left to do.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

After btrfs_readdir has gone through all the directory items, it
sets the directory f_pos to the largest possible int.  This way
applications that mix readdir with creating new files don't
end up in an endless loop finding the new directory items as they go.

It was a workaround for a bug in git, but the assumption was that if git
could make this looping mistake than it would be a common problem.

The largest possible int chosen was INT_LIMIT(typeof(file->f_pos),
and it is possible for that to be a larger number than 32 bit glibc
expects to come out of readdir.

This patches switches that to INT_LIMIT(off_t), which should keep
applications happy on 32 and 64 bit machines.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Just before reading a leaf, btrfs scans the node for blocks that are
close by and reads them too.  It tries to build up a large window
of IO looking for blocks that are within a max distance from the top
and bottom of the IO window.

This patch changes things to just look for blocks within 64k of the
target block.  It will trigger less IO and make for lower latencies on
the read size.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>

Now that bmap support is gone, this is the only way to get extent
mappings for userland.  These are still not valid for IO, but they
can tell us if a file has holes or how much fragmentation there is.
Signed-off-by: NYehuda Sadeh <yehuda@hq.newdream.net>

Swapfiles use bmap to build a list of extents belonging to the file,
and they assume these extents won't change over the life of the file.
They also use resulting list to do IO directly to the block device.

This causes problems for btrfs in a few ways:

btrfs returns logical block numbers through bmap, and these are not suitable
for IO.  They might translate to different devices, raid etc.

COW means that file block mappings are going to change frequently.

Using swapfiles on btrfs will lead to corruption, so we're avoiding the
problem for now by dropping bmap support entirely.  A later commit
will add fiemap support for people that really want to know how
a file is laid out.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

To improve performance, btrfs_sync_log merges tree log sync
requests. But it wrongly merges sync requests for different
tree logs. If multiple tree logs are synced at the same time,
only one of them actually gets synced.

This patch has following changes to fix the bug:

Move most tree log related fields in btrfs_fs_info to
btrfs_root. This allows merging sync requests separately
for each tree log.

Don't insert root item into the log root tree immediately
after log tree is allocated. Root item for log tree is
inserted when log tree get synced for the first time. This
allows syncing the log root tree without first syncing all
log trees.

At tree-log sync, btrfs_sync_log first sync the log tree;
then updates corresponding root item in the log root tree;
sync the log root tree; then update the super block.
Signed-off-by: NYan Zheng <zheng.yan@oracle.com>

a bug in open_ctree:

struct btrfs_root *open_ctree(..)
{
....
	if (!extent_root || !tree_root || !fs_info ||
	    !chunk_root || !dev_root || !csum_root) {
		err = -ENOMEM;
		goto fail;
//When code flow goes to "fail", fs_info may be NULL or uninitialized.
	}
....

fail:
	btrfs_close_devices(fs_info->fs_devices);// !
	btrfs_mapping_tree_free(&fs_info->mapping_tree);// !

	kfree(extent_root);
	kfree(tree_root);
	bdi_destroy(&fs_info->bdi);// !
...
)
Signed-off-by: NQinghuang Feng <qhfeng.kernel@gmail.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

replace_one_extent searches tree leaves for references to a given extent. It
stops searching if it goes beyond the last possible position.

The last possible position is computed by adding the starting offset of a found
file extent to the full size of the extent. The code uses physical size of the
extent as the full size. This is incorrect when compression is used.

The fix is get the full size from ram_bytes field of file extent item.
Signed-off-by: NYan Zheng <zheng.yan@oracle.com>

Change one typedef to a regular enum, and remove an unused one.
Signed-off-by: NJan Engelhardt <jengelh@medozas.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Removed duplicated #include "compat.h"in
fs/btrfs/extent-tree.c
Signed-off-by: NHuang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

btrfs_extent_post_op calls finish_current_insert and del_pending_extents. They
both may enter infinite loops.

finish_current_insert enters infinite loop if it only finds some backrefs to
update.  The fix is to check for pending backref updates before restarting the
loop.

The infinite loop in del_pending_extents is due to a the skipped variable
not being properly reset before looping around.
Signed-off-by: NYan Zheng <zheng.yan@oracle.com>

We should hold the block_group_cache_lock while modifying the
block groups red-black tree. Thank you,
Signed-off-by: NYan Zheng <zheng.yan@oracle.com>

Merge list_for_each* and list_entry to list_for_each_entry*
Signed-off-by: NQinghuang Feng <qhfeng.kernel@gmail.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

kthread_run() returns the kthread or ERR_PTR(-ENOMEM), not NULL.
Signed-off-by: NQinghuang Feng <qhfeng.kernel@gmail.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The "devid <xxx> transid <xxx>" printk in btrfs_scan_one_device()
actually follows another printk that doesn't end in a newline (since the
intention is for the two printks to make one line of output), so the
KERN_INFO just ends up messing up the output:

    device label exp <6>devid 1 transid 9 /dev/sda5

Fix this by changing the extra KERN_INFO to KERN_CONT.
Signed-off-by: NRoland Dreier <rolandd@cisco.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Removed unused #include <version.h>'s in btrfs
Signed-off-by: NHuang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Andrew's review of the xattr code revealed some minor issues that this patch
addresses.  Just an error return fix, got rid of a useless statement and
commented one of the trickier parts of __btrfs_getxattr.
Signed-off-by: NJosef Bacik <jbacik@redhat.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

- Remove the unused local variable 'len';
- Check return value of kmalloc().
Signed-off-by: NWang Cong <wangcong@zeuux.org>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The structure used to send device in btrfs ioctl calls was not
properly aligned, and so 32 bit ioctls would not work properly on
64 bit kernels.

We could fix this with compat ioctls, but we're just one byte away
and it doesn't make sense at this stage to carry about the compat ioctls
forever at this stage in the project.

This patch brings the ioctl arg up to an evenly aligned 4k.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Btrfs maintains a queue of async bio submissions so the checksumming
threads don't have to wait on get_request_wait.  In order to avoid
extra wakeups, this code has a running_pending flag that is used
to tell new submissions they don't need to wake the thread.

When the threads notice congestion on a single device, they
may decide to requeue the job and move on to other devices.  This
makes sure the running_pending flag is cleared before the
job is requeued.

It should help avoid IO stalls by making sure the task is woken up
when new submissions come in.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Use the standard magic.h for btrfs and squashfs.
Signed-off-by: NQinghuang Feng <qhfeng.kernel@gmail.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Cc: Chris Mason <chris.mason@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit c4be0c1d added the ability for
write_super_lockfs to return errors, and renamed them to match.  But
btrfs didn't get converted.

Do the minimal conversion to make it compile again.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Each subvolume has an extent_state_tree used to mark metadata
that needs to be sent to disk while syncing the tree.  This is
used in addition to the dirty bits on the pages themselves so that
a single subvolume can be sent to disk efficiently in disk order.

Normally this marking happens in btrfs_alloc_free_block, which also does
special recording of dirty tree blocks for the tree log roots.

Yan Zheng noticed that when the root of the log tree is allocated, it is added
to the wrong writeback list.  The fix used here is to explicitly set
it dirty as part of tree log creation.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This is already in the arch specific directories in mainline and
shouldn't be copied into btrfs.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Signed-off-by: NChris Mason <chris.mason@oracle.com>

None of the checksum verification code schedules, so we can use the faster
kmap_atomic
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Checksum verification happens in a helper thread, and there is no
need to mess with interrupts.  This switches to kmap() instead.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This patch contains following things.

1) Limit the max size of btrfs_ordered_sum structure to PAGE_SIZE.  This
struct is kmalloced so we want to keep it reasonable.

2) Replace copy_extent_csums by btrfs_lookup_csums_range.  This was
duplicated code in tree-log.c

3) Remove replay_one_csum. csum items are replayed at the same time as
   replaying file extents. This guarantees we only replay useful csums.

4) nbytes accounting fix.
Signed-off-by: NYan Zheng <zheng.yan@oracle.com>

btrfs_drop_extents doesn't change file extent's ram_bytes
in the case of booked extent. To be consistent, we should
also not change ram_bytes when truncating existing extent.
Signed-off-by: NYan Zheng <zheng.yan@oracle.com>

Snapshot creation happens at a specific time during transaction commit.  We
need to make sure the code called by snapshot creation doesn't wait
for the running transaction to commit.

This changes btrfs_delete_inode and finish_pending_snaps to use
btrfs_join_transaction instead of btrfs_start_transaction to avoid deadlocks.

It would be better if btrfs_delete_inode didn't use the join, but the
call path that triggers it is:

btrfs_commit_transaction->create_pending_snapshots->
create_pending_snapshot->btrfs_lookup_dentry->
fixup_tree_root_location->btrfs_read_fs_root->
btrfs_read_fs_root_no_name->btrfs_orphan_cleanup->iput

This will be fixed in a later patch by moving the orphan cleanup to the
cleaner thread.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Signed-off-by: NChris Mason <chris.mason@oracle.com>

They should stay out until this is turned into generic code.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

There were many, most are fixed now.  struct-funcs.c generates some warnings
but these are bogus.
Signed-off-by: NChris Mason <chris.mason@oracle.com>