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| author | Paulo Alcantara <pc@cjr.nz> | 2020-04-20 19:42:57 -0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-05-10 10:31:27 +0200 |
| commit | c46330d4dabf48ca826bad1aeda0568684c6a567 (patch) | |
| tree | 7ad1580b404dde53811dda9715fb3b8a66338c56 /fs | |
| parent | 84778248e013eacafb16ea0261fd4de4dd2f4497 (diff) | |
| download | linux-stable-c46330d4dabf48ca826bad1aeda0568684c6a567.tar.gz linux-stable-c46330d4dabf48ca826bad1aeda0568684c6a567.tar.bz2 linux-stable-c46330d4dabf48ca826bad1aeda0568684c6a567.zip | |
cifs: do not share tcons with DFS
[ Upstream commit 65303de829dd6d291a4947c1a31de31896f8a060 ]
This disables tcon re-use for DFS shares.
tcon->dfs_path stores the path that the tcon should connect to when
doing failing over.
If that tcon is used multiple times e.g. 2 mounts using it with
different prefixpath, each will need a different dfs_path but there is
only one tcon. The other solution would be to split the tcon in 2
tcons during failover but that is much harder.
tcons could not be shared with DFS in cifs.ko because in a
DFS namespace like:
//domain/dfsroot -> /serverA/dfsroot, /serverB/dfsroot
//serverA/dfsroot/link -> /serverA/target1/aa/bb
//serverA/dfsroot/link2 -> /serverA/target1/cc/dd
you can see that link and link2 are two DFS links that both resolve to
the same target share (/serverA/target1), so cifs.ko will only contain a
single tcon for both link and link2.
The problem with that is, if we (auto)mount "link" and "link2", cifs.ko
will only contain a single tcon for both DFS links so we couldn't
perform failover or refresh the DFS cache for both links because
tcon->dfs_path was set to either "link" or "link2", but not both --
which is wrong.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/cifs/connect.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 52589ea4e3c0..721b2560caa7 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -3362,6 +3362,10 @@ cifs_find_tcon(struct cifs_ses *ses, struct smb_vol *volume_info) spin_lock(&cifs_tcp_ses_lock); list_for_each(tmp, &ses->tcon_list) { tcon = list_entry(tmp, struct cifs_tcon, tcon_list); +#ifdef CONFIG_CIFS_DFS_UPCALL + if (tcon->dfs_path) + continue; +#endif if (!match_tcon(tcon, volume_info)) continue; ++tcon->tc_count; |