Lockdep complains about use of the iolock in inode reclaim context
because it doesn't understand that reclaim has the last reference to
the inode, and thus an iolock->reclaim->iolock deadlock is not
possible.
The iolock is technically not necessary in xfs_inactive() and was
only added to appease an assert in xfs_free_eofblocks(), which can
be called from other non-reclaim contexts. Therefore, just kill the
assert and drop the use of the iolock from reclaim context to quiet
lockdep.
Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx>
---
fs/xfs/xfs_bmap_util.c | 8 +++-----
fs/xfs/xfs_inode.c | 9 +++++----
2 files changed, 8 insertions(+), 9 deletions(-)
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 4d1920e..de94798 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -903,9 +903,9 @@ xfs_can_free_eofblocks(struct xfs_inode *ip, bool force)
}
/*
- * This is called by xfs_inactive to free any blocks beyond eof
- * when the link count isn't zero and by xfs_dm_punch_hole() when
- * punching a hole to EOF.
+ * This is called to free any blocks beyond eof. The caller must hold
+ * IOLOCK_EXCL unless we are in the inode reclaim path and have the only
+ * reference to the inode.
*/
int
xfs_free_eofblocks(
@@ -920,8 +920,6 @@ xfs_free_eofblocks(
struct xfs_bmbt_irec imap;
struct xfs_mount *mp = ip->i_mount;
- ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
-
/*
* Figure out if there are any blocks beyond the end
* of the file. If not, then there is nothing to do.
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 7605d83..ec9826c 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1906,12 +1906,13 @@ xfs_inactive(
* force is true because we are evicting an inode from the
* cache. Post-eof blocks must be freed, lest we end up with
* broken free space accounting.
+ *
+ * Note: don't bother with iolock here since lockdep complains
+ * about acquiring it in reclaim context. We have the only
+ * reference to the inode at this point anyways.
*/
- if (xfs_can_free_eofblocks(ip, true)) {
- xfs_ilock(ip, XFS_IOLOCK_EXCL);
+ if (xfs_can_free_eofblocks(ip, true))
xfs_free_eofblocks(ip);
- xfs_iunlock(ip, XFS_IOLOCK_EXCL);
- }
return;
}
--
2.7.4
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