cache block group had a few bugs in the error handling code,
this makes sure paths get properly released and the correct return value
goes out.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

It was incorrectly adding an extra sizeof(struct btrfs_item) and causing
false positives (oops)
Signed-off-by: NChris Mason <chris.mason@oracle.com>

I had incorrectly disabled the check for the block number being correct
in the header block.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

More testing has turned up a bug, disable this for now.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This is the same way the transaction code makes sure that all the
other tree blocks are safely on disk.  There's an extent_io tree
for each root, and any blocks allocated to the tree logs are
recorded in that tree.

At tree-log sync, the extent_io tree is walked to flush down the
dirty pages and wait for them.

The main benefit is less time spent walking the tree log and skipping
clean pages, and getting sequential IO down to the drive.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This changes the log tree copy code to use btrfs_insert_items and
to work in larger batches where possible.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Since tree log blocks get freed every transaction, they never really
need to be written to disk.  This skips the step where we update
metadata to record they were allocated.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

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

Drop i_mutex during the commit

Don't bother doing the fsync at all unless the dir is marked as dirtied
and needing fsync in this transaction.  For directories, this means
that someone has unlinked a file from the dir without fsyncing the
file.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

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

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

* Pin down data blocks to prevent them from being reallocated like so:

trans 1: allocate file extent
trans 2: free file extent
trans 3: free file extent during old snapshot deletion
trans 3: allocate file extent to new file
trans 3: fsync new file

Before the tree logging code, this was legal because the fsync
would commit the transation that did the final data extent free
and the transaction that allocated the extent to the new file
at the same time.

With the tree logging code, the tree log subtransaction can commit
before the transaction that freed the extent.  If we crash,
we're left with two different files using the extent.

* Don't wait in start_transaction if log replay is going on.  This
avoids deadlocks from iput while we're cleaning up link counts in the
replay code.

* Don't deadlock in replay_one_name by trying to read an inode off
the disk while holding paths for the directory

* Hold the buffer lock while we mark a buffer as written.  This
closes a race where someone is changing a buffer while we write it.
They are supposed to mark it dirty again after they change it, but
this violates the cow rules.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

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

Orphan items use BTRFS_ORPHAN_OBJECTID (-5UUL) as key objectid. This
affects the find free objectid functions, inode objectid can easily
overflow after orphan file cleanup.

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

Fix a bunch of trivial sparse complaints.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

btrfs_ilookup is unused, which is good because a normal filesystem
should never have to use ilookup anyway.  Remove it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Add two missing endianess conversions in this function, found by sparse.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

d_obtain_alias is intended as a tailcall that can pass in errors encoded
in the inode pointer if needed, so use it that way instead of
duplicating the error handling.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

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

File syncs and directory syncs are optimized by copying their
items into a special (copy-on-write) log tree.  There is one log tree per
subvolume and the btrfs super block points to a tree of log tree roots.

After a crash, items are copied out of the log tree and back into the
subvolume.  See tree-log.c for all the details.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

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

btrfs actually stores the whole xattr name, including the prefix ondisk,
so using the generic resolver that strips off the prefix is not very
helpful.  Instead do the real ondisk xattrs manually and only use the
generic resolver for synthetic xattrs like ACLs.

(Sorry Josef for guiding you towards the wrong direction here intially)
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The ->list handler is really not useful at all, because we always call
btrfs_xattr_generic_list anyway.  After this is done
find_btrfs_xattr_handler becomes unused, and it becomes obvious that the
temporary name buffer allocation isn't needed but we can directly copy
into the supplied buffer.

Tested with various getfattr -d calls on varying xattr lists.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

This patch makes btrfs so it will compile properly when acls are disabled.  I
tested this and it worked with CONFIG_FS_POSIX_ACL off and on.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

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

The current code waits for the count of async bio submits to get below
a given threshold if it is too high right after adding the latest bio
to the work queue.  This isn't optimal because the caller may have
sequential adjacent bios pending they are waiting to send down the pipe.

This changeset requires the caller to wait on the async bio count,
and changes the async checksumming submits to wait for async bios any
time they self throttle.

The end result is much higher sequential throughput.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

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

Date: Tue, 19 Aug 2008 22:33:04 +0100
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Date: Tue, 19 Aug 2008 22:20:17 +0100
btrfs_lookup_fs_root() only finds subvol roots which have already been
seen and put into the cache. For btrfs_get_dentry() we actually have to
go to the medium -- so use btrfs_read_fs_root_no_name() instead.

In btrfs_get_parent(), notice when we've hit the root of the
subvolume and return the real root instead.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Date: Tue, 19 Aug 2008 19:21:57 +0100
Using a 64-bit hash as the readdir cookie is just asking for trouble.
And gets it, when we try to export the file system by NFS.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Date: Tue, 19 Aug 2008 16:49:35 +0100
This disappeared when I removed the special case for '.' in btrfs_lookup()
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Date: Mon, 18 Aug 2008 22:50:22 +0100
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Date: Mon, 18 Aug 2008 13:10:20 +0100
This means that subvolumes get a different fsid, and NFS exporting them
works properly.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Date: Mon, 18 Aug 2008 12:01:52 +0100
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Date: Sun, 17 Aug 2008 17:12:56 +0100
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Date: Sun, 17 Aug 2008 17:08:36 +0100
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Date: Sun, 17 Aug 2008 15:14:48 +0100
We never get asked by the VFS to lookup either of them, and we can
handle the readdir() case a lot more simply, too.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Date: Tue, 12 Aug 2008 14:13:26 +0100
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Date: Wed, 6 Aug 2008 19:42:33 +0100
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Date: Mon, 21 Jul 2008 02:01:56 +0530
Here's an implementation of NFS support for btrfs. It relies on the
fixes which are going in to 2.6.28 for the NFS readdir/lookup deadlock.

This uses the btrfs_iget helper introduced previously.

[dwmw2: Tidy up a little, switch to d_obtain_alias() w/compat routine,
	change fh_type,	store parent's root object ID where needed,
	fix some get_parent() and fs_to_dentry() bugs]
Signed-off-by: NBalaji Rao <balajirrao@gmail.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>