kernel/linux.git/fs/smb/client/dfs_cache.c, branch v6.12.91

smb: client: fix DFS interlink failover

2024-09-25T02:51:48+00:00

The DFS interlinks point to different DFS namespaces so make sure to use the correct DFS root server to chase any DFS links under it by storing the SMB session in dfs_ref_walk structure and then using it on every referral walk. Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

smb: client: improve purging of cached referrals

2024-09-25T02:51:48+00:00

Purge cached referrals that have a single target when reaching maximum of cache size as the client won't need them to failover. Otherwise remove oldest cache entry. Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

smb: client: avoid unnecessary reconnects when refreshing referrals

2024-09-25T02:51:47+00:00

Do not mark tcons for reconnect when current connection matches any of the targets returned by new referral even when there is no cached entry. Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

smb: client: refresh referral without acquiring refpath_lock

2024-04-02T15:11:43+00:00

Avoid refreshing DFS referral with refpath_lock acquired as the I/O could block for a while due to a potentially disconnected or slow DFS root server and then making other threads - that use same @server and don't require a DFS root server - unable to make any progress. Cc: stable@vger.kernel.org # 6.4+ Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

smb: client: guarantee refcounted children from parent session

2024-04-02T15:09:57+00:00

Avoid potential use-after-free bugs when walking DFS referrals, mounting and performing DFS failover by ensuring that all children from parent @tcon->ses are also refcounted. They're all needed across the entire DFS mount. Get rid of @tcon->dfs_ses_list while we're at it, too. Cc: stable@vger.kernel.org # 6.4+ Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202404021527.ZlRkIxgv-lkp@intel.com/ Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

smb: client: ensure to try all targets when finding nested links

2023-08-20T21:05:50+00:00

With current implementation, when a nested DFS link is found during mount(2), the client follows the referral and then try to connect to all of its targets. If all targets failed, the client bails out rather than retrying remaining targets from previous referral. Fix this by stacking all referrals and targets so the client can retry remaining targets from previous referrals in case all targets of current referral have failed. Thanks to samba, this can be easily tested like below * Run the following under dfs folder in samba server $ ln -s "msdfs:srv\\bad-share" link1 $ ln -s "msdfs:srv\\dfs\\link1,srv\\good-share" link0 * Before patch $ mount.cifs //srv/dfs/link0 /mnt -o ... mount error(2): No such file or directory Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)... * After patch $ mount.cifs //srv/dfs/link0 /mnt -o ... # ls /mnt bar fileshare1 sub Signed-off-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

smb: client: introduce DFS_CACHE_TGT_LIST()

2023-08-20T21:05:49+00:00

Add new helper which declares and initialises target list of a DFS referral rather having to do both separately. No functional changes. Signed-off-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

smb: client: fix shared DFS root mounts with different prefixes

2023-06-28T20:48:43+00:00

When having two DFS root mounts that are connected to same namespace, same mount options but different prefix paths, we can't really use the shared @server->origin_fullpath when chasing DFS links in them. Move the origin_fullpath field to cifs_tcon structure so when having shared DFS root mounts with different prefix paths, and we need to chase any DFS links, dfs_get_automount_devname() will pick up the correct full path out of the @tcon that will be used for the new mount. Before patch mount.cifs //dom/dfs/dir /mnt/1 -o ... mount.cifs //dom/dfs /mnt/2 -o ... # shared server, ses, tcon # server: origin_fullpath=//dom/dfs/dir # @server->origin_fullpath + '/dir/link1' $ ls /mnt/2/dir/link1 ls: cannot open directory '/mnt/2/dir/link1': No such file or directory After patch mount.cifs //dom/dfs/dir /mnt/1 -o ... mount.cifs //dom/dfs /mnt/2 -o ... # shared server & ses # tcon_1: origin_fullpath=//dom/dfs/dir # tcon_2: origin_fullpath=//dom/dfs # @tcon_2->origin_fullpath + '/dir/link1' $ ls /mnt/2/dir/link1 dir0 dir1 dir10 dir3 dir5 dir6 dir7 dir9 target2_file.txt tsub Fixes: 8e3554150d6c ("cifs: fix sharing of DFS connections") Signed-off-by: Paulo Alcantara (SUSE) Signed-off-by: Steve French

smb: move client and server files to common directory fs/smb

2023-05-24T21:29:21+00:00

Move CIFS/SMB3 related client and server files (cifs.ko and ksmbd.ko and helper modules) to new fs/smb subdirectory: fs/cifs --> fs/smb/client fs/ksmbd --> fs/smb/server fs/smbfs_common --> fs/smb/common Suggested-by: Linus Torvalds Acked-by: Namjae Jeon Signed-off-by: Steve French