xfs: pull up iolock from xfs_free_eofblocks()
xfs_free_eofblocks() requires the IOLOCK_EXCL lock, but is called from
different contexts where the lock may or may not be held. The
need_iolock parameter exists for this reason, to indicate whether
xfs_free_eofblocks() must acquire the iolock itself before it can
proceed.
This is ugly and confusing. Simplify the semantics of
xfs_free_eofblocks() to require the caller to acquire the iolock
appropriately and kill the need_iolock parameter. While here, the mp
param can be removed as well as the xfs_mount is accessible from the
xfs_inode structure. This patch does not change behavior.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-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>
diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 70ca4f6..c6b698f 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1322,7 +1322,7 @@ xfs_inode_free_eofblocks(
int flags,
void *args)
{
- int ret;
+ int ret = 0;
struct xfs_eofblocks *eofb = args;
bool need_iolock = true;
int match;
@@ -1358,19 +1358,25 @@ xfs_inode_free_eofblocks(
return 0;
/*
- * A scan owner implies we already hold the iolock. Skip it in
- * xfs_free_eofblocks() to avoid deadlock. This also eliminates
- * the possibility of EAGAIN being returned.
+ * A scan owner implies we already hold the iolock. Skip it here
+ * to avoid deadlock.
*/
if (eofb->eof_scan_owner == ip->i_ino)
need_iolock = false;
}
- ret = xfs_free_eofblocks(ip->i_mount, ip, need_iolock);
-
- /* don't revisit the inode if we're not waiting */
- if (ret == -EAGAIN && !(flags & SYNC_WAIT))
- ret = 0;
+ /*
+ * If the caller is waiting, return -EAGAIN to keep the background
+ * scanner moving and revisit the inode in a subsequent pass.
+ */
+ if (need_iolock && !xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
+ if (flags & SYNC_WAIT)
+ ret = -EAGAIN;
+ return ret;
+ }
+ ret = xfs_free_eofblocks(ip);
+ if (need_iolock)
+ xfs_iunlock(ip, XFS_IOLOCK_EXCL);
return ret;
}