| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.10 16/56] NFSv4: dont set SETATTR for O_RDONLY|O_EXCL | Date | Tue, 29 Sep 2015 15:47:04 +0200 |
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3.10-stable review patch. If anyone has any objections, please let me know.
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From: NeilBrown <neilb@suse.com>
commit efcbc04e16dfa95fef76309f89710dd1d99a5453 upstream.
It is unusual to combine the open flags O_RDONLY and O_EXCL, but it appears that libre-office does just that.
[pid 3250] stat("/home/USER/.config", {st_mode=S_IFDIR|0700, st_size=8192, ...}) = 0 [pid 3250] open("/home/USER/.config/libreoffice/4-suse/user/extensions/buildid", O_RDONLY|O_EXCL <unfinished ...>
NFSv4 takes O_EXCL as a sign that a setattr command should be sent, probably to reset the timestamps.
When it was an O_RDONLY open, the SETATTR command does not identify any actual attributes to change. If no delegation was provided to the open, the SETATTR uses the all-zeros stateid and the request is accepted (at least by the Linux NFS server - no harm, no foul).
If a read-delegation was provided, this is used in the SETATTR request, and a Netapp filer will justifiably claim NFS4ERR_BAD_STATEID, which the Linux client takes as a sign to retry - indefinitely.
So only treat O_EXCL specially if O_CREAT was also given.
Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/nfs/nfs4proc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2043,7 +2043,7 @@ static int _nfs4_do_open(struct inode *d if (status != 0) goto err_opendata_put; - if ((opendata->o_arg.open_flags & O_EXCL) && + if ((opendata->o_arg.open_flags & (O_CREAT|O_EXCL)) == (O_CREAT|O_EXCL) && (opendata->o_arg.createmode != NFS4_CREATE_GUARDED)) { nfs4_exclusive_attrset(opendata, sattr);
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