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| author | Andreas Gruenbacher <agruenba@redhat.com> | 2018-06-20 01:10:55 +0300 |
|---|---|---|
| committer | Darrick J. Wong <darrick.wong@oracle.com> | 2018-06-20 01:10:55 +0300 |
| commit | ebf00be37de35788cad72f4f20b4a39e30c0be4a (patch) | |
| tree | da2cb75db298aea59b6b9f0051abe2d75153fb70 /mm/percpu-vm.c | |
| parent | 3d7b6b21f6c590c4d70b311bbdd78a214637c9c7 (diff) | |
| download | linux-ebf00be37de35788cad72f4f20b4a39e30c0be4a.tar.xz | |
iomap: complete partial direct I/O writes synchronously
According to xfstest generic/240, applications seem to expect direct I/O
writes to either complete as a whole or to fail; short direct I/O writes
are apparently not appreciated. This means that when only part of an
asynchronous direct I/O write succeeds, we can either fail the entire
write, or we can wait for the partial write to complete and retry the
remaining write as buffered I/O. The old __blockdev_direct_IO helper
has code for waiting for partial writes to complete; the new
iomap_dio_rw iomap helper does not.
The above mentioned fallback mode is needed for gfs2, which doesn't
allow block allocations under direct I/O to avoid taking cluster-wide
exclusive locks. As a consequence, an asynchronous direct I/O write to
a file range that contains a hole will result in a short write. In that
case, wait for the short write to complete to allow gfs2 to recover.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Diffstat (limited to 'mm/percpu-vm.c')
0 files changed, 0 insertions, 0 deletions