Commit Graph

31 Commits

Author SHA1 Message Date
Chris Mason e5e9a5206a Btrfs: avoid races between super writeout and device list updates
On multi-device filesystems, btrfs writes supers to all of the devices
before considering a sync complete.  There wasn't any additional
locking between super writeout and the device list management code
because device management was done inside a transaction and
super writeout only happened  with no transation writers running.

With the btrfs fsync log and other async transaction updates, this
has been racey for some time.  This adds a mutex to protect
the device list.  The existing volume mutex could not be reused due to
transaction lock ordering requirements.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 15:17:02 -04:00
Chris Mason c289811cc0 Btrfs: autodetect SSD devices
During mount, btrfs will check the queue nonrot flag
for all the devices found in the FS.  If they are all
non-rotating, SSD mode is enabled by default.

If the FS was mounted with -o nossd, the non-rotating
flag is ignored.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10 11:29:52 -04:00
Chris Ball d6397baee4 Btrfs: When shrinking, only update disk size on success
Previously, we updated a device's size prior to attempting a shrink
operation.  This patch moves the device resizing logic to only happen if
the shrink completes successfully.  In the process, it introduces a new
field to btrfs_device -- disk_total_bytes -- to track the on-disk size.

Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27 07:40:51 -04:00
Chris Mason ffbd517d5a Btrfs: use WRITE_SYNC for synchronous writes
Part of reducing fsync/O_SYNC/O_DIRECT latencies is using WRITE_SYNC for
writes we plan on waiting on in the near future.  This patch
mirrors recent changes in other filesystems and the generic code to
use WRITE_SYNC when WB_SYNC_ALL is passed and to use WRITE_SYNC for
other latency critical writes.

Btrfs uses async worker threads for checksumming before the write is done,
and then again to actually submit the bios.  The bio submission code just
runs a per-device list of bios that need to be sent down the pipe.

This list is split into low priority and high priority lists so the
WRITE_SYNC IO happens first.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-20 15:53:08 -04:00
Wu Fengguang d4a789474a Btrfs: fix typos in comments
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-02 16:46:06 -04:00
Yan Zheng e4404d6e8d Btrfs: shared seed device
This patch makes seed device possible to be shared by
multiple mounted file systems. The sharing is achieved
by cloning seed device's btrfs_fs_devices structure.
Thanks you,

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-12-12 10:03:26 -05:00
Yan Zheng a512bbf855 Btrfs: superblock duplication
This patch implements superblock duplication. Superblocks
are stored at offset 16K, 64M and 256G on every devices.
Spaces used by superblocks are preserved by the allocator,
which uses a reverse mapping function to find the logical
addresses that correspond to superblocks. Thank you,

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-12-08 16:46:26 -05:00
Christoph Hellwig 97288f2c71 Btrfs: corret fmode_t annotations
Make sure to propagate fmode_t properly and use the right constants for
it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2008-12-02 06:36:09 -05:00
Chris Mason 15916de835 Btrfs: Fixes for 2.6.28-rc API changes
* open/close_bdev_excl -> open/close_bdev_exclusive
* blkdev_issue_discard takes a GFP mask now
* Fix blkdev_issue_discard usage now that it is enabled

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-11-19 21:17:22 -05:00
Yan Zheng 2b82032c34 Btrfs: Seed device support
Seed device is a special btrfs with SEEDING super flag
set and can only be mounted in read-only mode. Seed
devices allow people to create new btrfs on top of it.

The new FS contains the same contents as the seed device,
but it can be mounted in read-write mode.

This patch does the following:

1) split code in btrfs_alloc_chunk into two parts. The first part does makes
the newly allocated chunk usable, but does not do any operation that modifies
the chunk tree. The second part does the the chunk tree modifications. This
division is for the bootstrap step of adding storage to the seed device.

2) Update device management code to handle seed device.
The basic idea is: For an FS grown from seed devices, its
seed devices are put into a list. Seed devices are
opened on demand at mounting time. If any seed device is
missing or has been changed, btrfs kernel module will
refuse to mount the FS.

3) make btrfs_find_block_group not return NULL when all
block groups are read-only.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-11-17 21:11:30 -05:00
Chris Mason 7d2b4daa67 Btrfs: Fix the multi-bio code to save the original bio for completion
The multi-bio code is responsible for duplicating blocks in raid1 and
single spindle duplication.  It has counters to make sure all of
the locations for a given extent are properly written before io completion
is returned to the higher layers.

But, it didn't always complete the same bio it was given, sometimes a
clone was completed instead.  This lead to problems with the async
work queues because they saved a pointer to the bio in a struct off
bi_private.

The fix is to remember the original bio and only complete that one.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:06 -04:00
Chris Mason 8b71284292 Btrfs: Add async worker threads for pre and post IO checksumming
Btrfs has been using workqueues to spread the checksumming load across
other CPUs in the system.  But, workqueues only schedule work on the
same CPU that queued the work, giving them a limited benefit for systems with
higher CPU counts.

This code adds a generic facility to schedule work with pools of kthreads,
and changes the bio submission code to queue bios up.  The queueing is
important to make sure large numbers of procs on the system don't
turn streaming workloads into random workloads by sending IO down
concurrently.

The end result of all of this is much higher performance (and CPU usage) when
doing checksumming on large machines.  Two worker pools are created,
one for writes and one for endio processing.  The two could deadlock if
we tried to service both from a single pool.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason a0af469b58 Fix btrfs_open_devices to deal with changes since the scan ioctls
Devices can change after the scan ioctls are done, and btrfs_open_devices
needs to be able to verify them as they are opened and used by the FS.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason dfe2502068 Btrfs: Add mount -o degraded to allow mounts to continue with missing devices
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:03 -04:00
Chris Mason a061fc8da7 Btrfs: Add support for online device removal
This required a few structural changes to the code that manages bdev pointers:

The VFS super block now gets an anon-bdev instead of a pointer to the
lowest bdev.  This allows us to avoid swapping the super block bdev pointer
around at run time.

The code to read in the super block no longer goes through the extent
buffer interface.  Things got ugly keeping the mapping constant.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason a236aed14c Btrfs: Deal with failed writes in mirrored configurations
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason ec44a35cbe Btrfs: Add balance ioctl to restripe the chunks
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason 788f20eb5a Btrfs: Add new ioctl to add devices
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason 8f18cf1339 Btrfs: Make the resizer work based on shrinking and growing devices
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason b30757178d Btrfs: Add a special device list for chunk allocations
This allows other code that needs to walk every device in the FS to do so
without locking against allocations.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason f2d8d74d78 Btrfs: Make an unplug function that doesn't unplug every spindle
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:02 -04:00
Chris Mason e17cade25f Btrfs: Add chunk uuids and update multi-device back references
Block headers now store the chunk tree uuid

Chunk items records the device uuid for each stripes

Device extent items record better back refs to the chunk tree

Block groups record better back refs to the chunk tree

The chunk tree format has also changed.  The objectid of BTRFS_CHUNK_ITEM_KEY
used to be the logical offset of the chunk.  Now it is a chunk tree id,
with the logical offset being stored in the offset field of the key.

This allows a single chunk tree to record multiple logical address spaces,
upping the number of bytes indexed by a chunk tree from 2^64 to
2^128.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason f29844623d Btrfs: Write out all super blocks on commit, and bring back proper barrier support
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason f188591e98 Btrfs: Retry metadata reads in the face of checksum failures
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason cea9e4452e Change btrfs_map_block to return a structure with mappings for all stripes
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 8790d502e4 Btrfs: Add support for mirroring across drives
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 8a4b83cc8b Btrfs: Add support for device scanning and detection ioctls
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 239b14b32d Btrfs: Bring back mount -o ssd optimizations
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 0d81ba5dbe Btrfs: Move device information into the super block so it can be scanned
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 6324fbf334 Btrfs: Dynamic chunk and block group allocation
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00
Chris Mason 0b86a832a1 Btrfs: Add support for multiple devices per filesystem
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:00 -04:00