This is a note to let you know that I've just added the patch titled
nfsd: Fix possible BUG_ON firing in set_change_info
to the 2.6.32-longterm tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/longterm/longterm-queue-2.6.32.git;a=summary
The filename of the patch is:
nfsd-fix-possible-bug_on-firing-in-set_change_info.patch
and it can be found in the queue-2.6.32 subdirectory.
If you, or anyone else, feels it should not be added to the 2.6.32 longterm
tree,
please let <[email protected]> know about it.
>From c1ac3ffcd0bc7e9617f62be8c7043d53ab84deac Mon Sep 17 00:00:00 2001
From: Neil Brown <[email protected]>
Date: Thu, 2 Dec 2010 11:14:30 +1100
Subject: nfsd: Fix possible BUG_ON firing in set_change_info
From: Neil Brown <[email protected]>
commit c1ac3ffcd0bc7e9617f62be8c7043d53ab84deac upstream.
If vfs_getattr in fill_post_wcc returns an error, we don't
set fh_post_change.
For NFSv4, this can result in set_change_info triggering a BUG_ON.
i.e. fh_post_saved being zero isn't really a bug.
So:
- instead of BUGging when fh_post_saved is zero, just clear ->atomic.
- if vfs_getattr fails in fill_post_wcc, take a copy of i_ctime anyway.
This will be used i seg_change_info, but not overly trusted.
- While we are there, remove the pointless 'if' statements in set_change_info.
There is no harm setting all the values.
Signed-off-by: NeilBrown <[email protected]>
Signed-off-by: J. Bruce Fields <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/nfsd/nfs3xdr.c | 6 ++++--
include/linux/nfsd/xdr4.h | 21 ++++++++++-----------
2 files changed, 14 insertions(+), 13 deletions(-)
--- a/fs/nfsd/nfs3xdr.c
+++ b/fs/nfsd/nfs3xdr.c
@@ -273,9 +273,11 @@ void fill_post_wcc(struct svc_fh *fhp)
err = vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry,
&fhp->fh_post_attr);
fhp->fh_post_change = fhp->fh_dentry->d_inode->i_version;
- if (err)
+ if (err) {
fhp->fh_post_saved = 0;
- else
+ /* Grab the ctime anyway - set_change_info might use it */
+ fhp->fh_post_attr.ctime = fhp->fh_dentry->d_inode->i_ctime;
+ } else
fhp->fh_post_saved = 1;
}
--- a/include/linux/nfsd/xdr4.h
+++ b/include/linux/nfsd/xdr4.h
@@ -480,18 +480,17 @@ static inline bool nfsd4_not_cached(stru
static inline void
set_change_info(struct nfsd4_change_info *cinfo, struct svc_fh *fhp)
{
- BUG_ON(!fhp->fh_pre_saved || !fhp->fh_post_saved);
- cinfo->atomic = 1;
+ BUG_ON(!fhp->fh_pre_saved);
+ cinfo->atomic = fhp->fh_post_saved;
cinfo->change_supported = IS_I_VERSION(fhp->fh_dentry->d_inode);
- if (cinfo->change_supported) {
- cinfo->before_change = fhp->fh_pre_change;
- cinfo->after_change = fhp->fh_post_change;
- } else {
- cinfo->before_ctime_sec = fhp->fh_pre_ctime.tv_sec;
- cinfo->before_ctime_nsec = fhp->fh_pre_ctime.tv_nsec;
- cinfo->after_ctime_sec = fhp->fh_post_attr.ctime.tv_sec;
- cinfo->after_ctime_nsec = fhp->fh_post_attr.ctime.tv_nsec;
- }
+
+ cinfo->before_change = fhp->fh_pre_change;
+ cinfo->after_change = fhp->fh_post_change;
+ cinfo->before_ctime_sec = fhp->fh_pre_ctime.tv_sec;
+ cinfo->before_ctime_nsec = fhp->fh_pre_ctime.tv_nsec;
+ cinfo->after_ctime_sec = fhp->fh_post_attr.ctime.tv_sec;
+ cinfo->after_ctime_nsec = fhp->fh_post_attr.ctime.tv_nsec;
+
}
int nfs4svc_encode_voidres(struct svc_rqst *, __be32 *, void *);
Patches currently in longterm-queue-2.6.32 which might be from [email protected] are
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