Commit graph

10 commits

Author SHA1 Message Date
David Chinner
2a82b8be8a [XFS] Concurrent Multi-File Data Streams
In media spaces, video is often stored in a frame-per-file format. When
dealing with uncompressed realtime HD video streams in this format, it is
crucial that files do not get fragmented and that multiple files a placed
contiguously on disk.

When multiple streams are being ingested and played out at the same time,
it is critical that the filesystem does not cross the streams and
interleave them together as this creates seek and readahead cache miss
latency and prevents both ingest and playout from meeting frame rate
targets.

This patch set creates a "stream of files" concept into the allocator to
place all the data from a single stream contiguously on disk so that RAID
array readahead can be used effectively. Each additional stream gets
placed in different allocation groups within the filesystem, thereby
ensuring that we don't cross any streams. When an AG fills up, we select a
new AG for the stream that is not in use.

The core of the functionality is the stream tracking - each inode that we
create in a directory needs to be associated with the directories' stream.
Hence every time we create a file, we look up the directories' stream
object and associate the new file with that object.

Once we have a stream object for a file, we use the AG that the stream
object point to for allocations. If we can't allocate in that AG (e.g. it
is full) we move the entire stream to another AG. Other inodes in the same
stream are moved to the new AG on their next allocation (i.e. lazy
update).

Stream objects are kept in a cache and hold a reference on the inode.
Hence the inode cannot be reclaimed while there is an outstanding stream
reference. This means that on unlink we need to remove the stream
association and we also need to flush all the associations on certain
events that want to reclaim all unreferenced inodes (e.g. filesystem
freeze).

SGI-PV: 964469
SGI-Modid: xfs-linux-melb:xfs-kern:29096a

Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Barry Naujok <bnaujok@sgi.com>
Signed-off-by: Donald Douwsma <donaldd@sgi.com>
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Vlad Apostolov <vapo@sgi.com>
2007-07-14 15:40:53 +10:00
Vlad Apostolov
93c189c114 [XFS] 956618: Linux crashes on boot with XFS-DMAPI filesystem when
CONFIG_XFS_TRACE is on

SGI-PV: 956618
SGI-Modid: xfs-linux-melb:xfs-kern:27196a

Signed-off-by: Vlad Apostolov <vapo@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-11-11 18:03:49 +11:00
Tim Shimmin
65e8697a12 [XFS] Remove v1 dir trace macro - missed in a past commit.
Signed-off-by: Tim Shimmin <tes@sgi.com>
2006-09-29 15:23:02 +10:00
Nathan Scott
d8ce753241 [XFS] Remove files from the build that are now unused.
Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-20 14:53:51 +10:00
Nathan Scott
d7b849da47 [XFS] Fix a Makefile issue related to exports.o handling.
Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-06-20 14:01:29 +10:00
Nathan Scott
bb19fba193 [XFS] Sync up one/two other minor changes missed in previous merges.
Signed-off-by: Nathan Scott <nathans@sgi.com>
2006-03-22 14:12:12 +11:00
Nathan Scott
7f248a81c5 [XFS] Cleanup cosmetic differences between source trees.
Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-11-03 16:14:31 +11:00
Nathan Scott
c9fc0d6a69 [XFS] Revert recent quota Makefile change, not in a fit state for merging.
Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-09-09 11:38:09 +10:00
Nathan Scott
eccdfcd6f8 [XFS] Fix modular XFS builds (Makefile botch).
Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-09-08 15:38:52 +10:00
Nathan Scott
cde410a99d [XFS] Sort out some cosmetic differences between XFS trees.
SGI-PV: 904196
SGI-Modid: xfs-linux-melb:xfs-kern:23719a

Signed-off-by: Nathan Scott <nathans@sgi.com>
2005-09-05 11:47:01 +10:00