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From 20fd9eadba0b46033571debc8927f29fc1b6c246 Mon Sep 17 00:00:00 2001
From: Mark Vitale <mvitale@sinenomine.net>
Date: Wed, 7 Dec 2016 11:11:45 -0500
Subject: [PATCH] Linux 4.10: have_submounts is gone
Linux commit f74e7b33c37e vfs: remove unused have_submounts() function
(v4.10-rc2) removes have_submounts from the tree after providing a
replacement (path_has_submounts) for its last in-tree caller, autofs.
However, it turns out that OpenAFS is better off not using the new
path_has_submounts. Instead, OpenAFS could/should have stopped using
have_submounts() much earlier, back in Linux v3.18 when d_invalidate
became void. At that time, most in-tree callers of have_submounts had
already been converted to use check_submounts_and_drop back in v3.12.
At v3.18, a series of commits modified check_submounts_and_drop to
automatically remove child submounts (instead of returning -EBUSY if a
submount was detected), then subsumed it into d_invalidate. The end
result was that VFS now implicitly handles much of the housekeeping
previously called explicitly by the various filesystem d_revalidate
routines:
- shrink_dcache_parent
- check_submounts_and_drop
- d_drop
- d_invalidate
All in-tree filesystem d_revalidate routines were updated to take
advantage of this new VFS support.
Modify afs_linux_dentry_revalidate to no longer perform any special
handling for invalid dentries when D_INVALIDATE_IS_VOID. Instead, allow
our VFS caller to properly clean up any invalid dentry when we return 0.
Reviewed-on: https://gerrit.openafs.org/12506
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit 789319bf0f2b26ad67995f8cbe88cee87a1bbdc0)
Change-Id: I7ed22338e7896f69a204be78ed0a4f6136a3dab8
---
src/afs/LINUX/osi_vnodeops.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/src/afs/LINUX/osi_vnodeops.c b/src/afs/LINUX/osi_vnodeops.c
index 4a8f0e9dc..816cdddd9 100644
--- a/src/afs/LINUX/osi_vnodeops.c
+++ b/src/afs/LINUX/osi_vnodeops.c
@@ -1318,6 +1318,24 @@ afs_linux_dentry_revalidate(struct dentry *dp, int flags)
good_dentry:
valid = 1;
+ goto done;
+
+ bad_dentry:
+ valid = 0;
+#ifndef D_INVALIDATE_IS_VOID
+ /* When (v3.18) d_invalidate was converted to void, it also started
+ * being called automatically from revalidate, and automatically
+ * handled:
+ * - shrink_dcache_parent
+ * - automatic detach of submounts
+ * - d_drop
+ * Therefore, after that point, OpenAFS revalidate logic no longer needs
+ * to do any of those things itself for invalid dentry structs. We only need
+ * to tell VFS it's invalid (by returning 0), and VFS will handle the rest.
+ */
+ if (have_submounts(dp))
+ valid = 1;
+#endif
done:
/* Clean up */
@@ -1328,6 +1346,7 @@ afs_linux_dentry_revalidate(struct dentry *dp, int flags)
if (credp)
crfree(credp);
+#ifndef D_INVALIDATE_IS_VOID
if (!valid) {
/*
* If we had a negative lookup for the name we want to forcibly
@@ -1340,15 +1359,9 @@ afs_linux_dentry_revalidate(struct dentry *dp, int flags)
} else
d_invalidate(dp);
}
-
+#endif
return valid;
- bad_dentry:
- if (have_submounts(dp))
- valid = 1;
- else
- valid = 0;
- goto done;
}
static void
--
2.12.0
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