linux.git/fs/cifs/dfs_cache.c, branch v5.17

cifs: call helper functions for marking channels for reconnect

2022-02-09T04:13:48+00:00

cifs_mark_tcp_ses_conns_for_reconnect helper function is now
meant to be used by any of the threads to mark a channel
(or all the channels) for reconnect.

Replace all such manual changes to tcpStatus to use this
helper function, which takes care that the right channels,
smb sessions and tcons are marked for reconnect.

Also includes one line minor change
Reported-by: kernel test robot 

Signed-off-by: Shyam Prasad N 
Signed-off-by: Steve French

cifs: cifs_ses_mark_for_reconnect should also update reconnect bits

2022-01-19T17:10:58+00:00

Recent restructuring of cifs_reconnect introduced a helper func
named cifs_ses_mark_for_reconnect, which updates the state of tcp
session for all the channels of a session for reconnect.

However, this does not update the session state and chans_need_reconnect
bitmask. This change fixes that.

Also, cifs_mark_tcp_sess_for_reconnect should mark set the bitmask
for all channels when the whole session is marked for reconnect.
Fixed that here too.

Signed-off-by: Shyam Prasad N 
Signed-off-by: Steve French

cifs: introduce cifs_ses_mark_for_reconnect() helper

2021-11-16T16:57:08+00:00

Use new cifs_ses_mark_for_reconnect() helper to mark all session
channels for reconnect instead of duplicating it in different places.

Signed-off-by: Paulo Alcantara (SUSE) 
Signed-off-by: Steve French

cifs: support nested dfs links over reconnect

2021-11-10T22:30:13+00:00

Mounting a dfs link that has nested links was already supported at
mount(2), so make it work over reconnect as well.

Make the following case work:

* mount //root/dfs/link /mnt -o ...
  - final share: /server/share

* in server settings
  - change target folder of /root/dfs/link3 to /server/share2
  - change target folder of /root/dfs/link2 to /root/dfs/link3
  - change target folder of /root/dfs/link to /root/dfs/link2

* mount -o remount,... /mnt
 - refresh all dfs referrals
 - mark current connection for failover
 - cifs_reconnect() reconnects to root server
 - tree_connect()
   * checks that /root/dfs/link2 is a link, then chase it
   * checks that root/dfs/link3 is a link, then chase it
   * finally tree connect to /server/share2

If the mounted share is no longer accessible and a reconnect had been
triggered, the client will retry it from both last referral
path (/root/dfs/link3) and original referral path (/root/dfs/link).

Any new referral paths found while chasing dfs links over reconnect,
it will be updated to TCP_Server_Info::leaf_fullpath, accordingly.

Signed-off-by: Paulo Alcantara (SUSE) 
Signed-off-by: Steve French

cifs: fix print of hdr_flags in dfscache_proc_show()

2021-11-10T02:44:07+00:00

Reorder the parameters in seq_printf() to correctly print header
flags.

Signed-off-by: Paulo Alcantara (SUSE) 
Reviewed-by: Shyam Prasad N 
Signed-off-by: Steve French

cifs: support share failover when remounting

2021-07-22T16:43:23+00:00

When remouting a DFS share, force a new DFS referral of the path and
if the currently cached targets do not match any of the new targets or
there was no cached targets, then mark it for reconnect.

For example:

    $ mount //dom/dfs/link /mnt -o username=foo,password=bar
    $ ls /mnt
    oldfile.txt

    change target share of 'link' in server settings

    $ mount /mnt -o remount,username=foo,password=bar
    $ ls /mnt
    newfile.txt

Signed-off-by: Paulo Alcantara (SUSE) 
Signed-off-by: Steve French

cifs: fix check of dfs interlinks

2021-06-21T02:28:17+00:00

Interlink is a special type of DFS link that resolves to a different
DFS domain-based namespace.  To determine whether it is an interlink
or not, check if ReferralServers and StorageServers bits are set to 1
and 0 respectively in ReferralHeaderFlags, as specified in MS-DFSC
3.1.5.4.5 Determining Whether a Referral Response is an Interlink.

Signed-off-by: Paulo Alcantara (SUSE) 
Reviewed-by: Aurelien Aptel 
Signed-off-by: Steve French

cifs: avoid starvation when refreshing dfs cache

2021-06-21T02:28:17+00:00

When refreshing the DFS cache, keep SMB2 IOCTL calls as much outside
critical sections as possible and avoid read/write starvation when
getting new DFS referrals by using broken or slow connections.

Signed-off-by: Paulo Alcantara (SUSE) 
Reviewed-by: Aurelien Aptel 
Signed-off-by: Steve French

cifs: set a minimum of 2 minutes for refreshing dfs cache

2021-06-21T02:28:17+00:00

We don't want to refresh the dfs cache in very short intervals, so
setting a minimum interval of 2 minutes is OK.

If it needs to be refreshed immediately, one could have the cache
cleared with

	$ echo 0 > /proc/fs/cifs/dfscache

and then remounting the dfs share.

Signed-off-by: Paulo Alcantara (SUSE) 
Reviewed-by: Aurelien Aptel 
Signed-off-by: Steve French

cifs: fix path comparison and hash calc

2021-06-21T02:28:17+00:00

Fix cache lookup and hash calculations when handling paths with
different cases.

Signed-off-by: Paulo Alcantara (SUSE) 
Reviewed-by: Aurelien Aptel 
Signed-off-by: Steve French