xfs: recall pNFS layouts on conflicting access

Recall all outstanding pNFS layouts and truncates, writes and similar extent
list modifying operations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Christoph Hellwig
2015-02-16 11:59:50 +11:00
committed by Dave Chinner
parent 527851124d
commit 781355c6e5
5 changed files with 64 additions and 7 deletions

View File

@@ -18,6 +18,36 @@
#include "xfs_bit.h"
#include "xfs_pnfs.h"
/*
* Ensure that we do not have any outstanding pNFS layouts that can be used by
* clients to directly read from or write to this inode. This must be called
* before every operation that can remove blocks from the extent map.
* Additionally we call it during the write operation, where aren't concerned
* about exposing unallocated blocks but just want to provide basic
* synchronization between a local writer and pNFS clients. mmap writes would
* also benefit from this sort of synchronization, but due to the tricky locking
* rules in the page fault path we don't bother.
*/
int
xfs_break_layouts(
struct inode *inode,
uint *iolock)
{
struct xfs_inode *ip = XFS_I(inode);
int error;
ASSERT(xfs_isilocked(ip, XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL));
while ((error = break_layout(inode, false) == -EWOULDBLOCK)) {
xfs_iunlock(ip, *iolock);
error = break_layout(inode, true);
*iolock = XFS_IOLOCK_EXCL;
xfs_ilock(ip, *iolock);
}
return error;
}
/*
* Get a unique ID including its location so that the client can identify
* the exported device.