The patch titled
knfsd-nfsd4-vary-maximum-delegation-limit-based-on-ram-size fix fix fix
has been added to the -mm tree. Its filename is
knfsd-nfsd4-vary-maximum-delegation-limit-based-on-ram-size-fix-fix-fix.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: knfsd-nfsd4-vary-maximum-delegation-limit-based-on-ram-size fix fix fix
From: "J. Bruce Fields" <bfields@xxxxxxxxxxxx>
This code would benefit from a little more explanation.
Also, I screwed up the previous patch and forgot to delete a line, so the
calculation here is off; fix it.
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxxxxxx>
Cc: Neil Brown <neilb@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/nfsd/nfs4state.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff -puN fs/nfsd/nfs4state.c~knfsd-nfsd4-vary-maximum-delegation-limit-based-on-ram-size-fix-fix-fix fs/nfsd/nfs4state.c
--- a/fs/nfsd/nfs4state.c~knfsd-nfsd4-vary-maximum-delegation-limit-based-on-ram-size-fix-fix-fix
+++ a/fs/nfsd/nfs4state.c
@@ -3198,13 +3198,27 @@ get_nfs4_grace_period(void)
return max(user_lease_time, lease_time) * HZ;
}
+/*
+ * Since the lifetime of a delegation isn't limited to that of an open, a
+ * client may quite reasonably hang on to a delegation as long as it has
+ * the inode cached. This becomes an obvious problem the first time a
+ * client's inode cache approaches the size of the server's total memory.
+ *
+ * For now we avoid this problem by imposing a hard limit on the number
+ * of delegations, which varies according to the server's memory size.
+ */
static void
set_max_delegations(void)
{
struct sysinfo sys;
si_meminfo(&sys);
- sys.totalram *= sys.mem_unit;
+ /*
+ * Allow at most 4 delegations per megabyte of RAM. Quick
+ * estimates suggest that in the worst case (where every delegation
+ * is for a different inode), a delegation could take about 1.5K,
+ * giving a worst case usage of about 6% of memory.
+ */
sys.totalram >>= (18 - PAGE_SHIFT);
max_delegations = (unsigned int) sys.totalram;
}
_
Patches currently in -mm which might be from bfields@xxxxxxxxxxxx are
nfs-refactor-ip-address-sanity-checks-in-nfs-client.patch
knfsd-nfsd4-fix-nfsv4-filehandle-size-units-confusion.patch
knfsd-nfsd4-silence-a-compiler-warning-in-acl-code.patch
knfsd-nfsd4-fix-handling-of-acl-errrors.patch
knfsd-nfsd-remove-unused-header-interfaceh.patch
knfsd-nfsd4-vary-maximum-delegation-limit-based-on-ram-size-fix.patch
knfsd-nfsd4-vary-maximum-delegation-limit-based-on-ram-size-fix-fix.patch
knfsd-nfsd4-vary-maximum-delegation-limit-based-on-ram-size-fix-fix-fix.patch
-
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