Since Linux 2.6.36 the writeback code has introduces various measures for
live lock prevention during sync(). Unfortunately some of these are
actively harmful for the XFS model, where the inode gets marked dirty for
metadata from the data I/O handler.
The older_than_this checks that are now more strictly enforced since
writeback: avoid livelocking WB_SYNC_ALL writeback
by only calling into __writeback_inodes_sb and thus only sampling the
current cut off time once. But on a slow enough devices the previous
asynchronous sync pass might not have fully completed yet, and thus XFS
might mark metadata dirty only after that sampling of the cut off time for
the blocking pass already happened. I have not myself reproduced this
myself on a real system, but by introducing artificial delay into the
XFS I/O completion workqueues it can be reproduced easily.
Fix this by iterating over all XFS inodes in ->sync_fs and log all that
are dirty. This might log inode that only got redirtied after the
previous pass, but given how cheap delayed logging of inodes is it
isn't a major concern for performance.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
If we are doing synchronous inode reclaim we block the VM from making
progress in memory reclaim. So if we encouter a flush locked inode
promote it in the delwri list and wake up xfsbufd to write it out now.
Without this we can get hangs of up to 30 seconds during workloads hitting
synchronous inode reclaim.
The scheme is copied from what we do for dquot reclaims.
Reported-by: Simon Kirby <sim@hostway.ca>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Simon Kirby <sim@hostway.ca>
Signed-off-by: Ben Myers <bpm@sgi.com>
We now have an i_dio_count filed and surrounding infrastructure to wait
for direct I/O completion instead of i_icount, and we have never needed
to iocount waits for buffered I/O given that we only set the page uptodate
after finishing all required work. Thus remove i_iocount, and replace
the actually needed waits with calls to inode_dio_wait.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Remove the xfs_buf_relse from xfs_bwrite and let the caller handle it to
mirror the delwri and read paths.
Also remove the mount pointer passed to xfs_bwrite, which is superflous now
that we have a mount pointer in the buftarg.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Alex Elder <aelder@sgi.com>
Use the move from Linux 2.6 to Linux 3.x as an excuse to kill the
annoying subdirectories in the XFS source code. Besides the large
amount of file rename the only changes are to the Makefile, a few
files including headers with the subdirectory prefix, and the binary
sysctl compat code that includes a header under fs/xfs/ from
kernel/.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Christoph Hellwig
Christoph Hellwig