kernel/linux.git/fs/smb/client/dfs_cache.c, branch linux-7.0.y

smb: client: use atomic_t for mnt_cifs_flags

2026-02-27T00:17:08+00:00

Use atomic_t for cifs_sb_info::mnt_cifs_flags as it's currently accessed locklessly and may be changed concurrently in mount/remount and reconnect paths. Signed-off-by: Paulo Alcantara (Red Hat) Reviewed-by: David Howells Cc: linux-cifs@vger.kernel.org Signed-off-by: Steve French

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

smb: client: handle lack of IPC in dfs_cache_refresh()

2025-10-30T01:13:05+00:00

In very rare cases, DFS mounts could end up with SMB sessions without any IPC connections. These mounts are only possible when having unexpired cached DFS referrals, hence not requiring any IPC connections during the mount process. Try to establish those missing IPC connections when refreshing DFS referrals. If the server is still rejecting it, then simply ignore and leave expired cached DFS referral for any potential DFS failovers. Reported-by: Jay Shin Signed-off-by: Paulo Alcantara (Red Hat) Cc: David Howells Cc: linux-cifs@vger.kernel.org Signed-off-by: Steve French

smb: client: get rid of kstrdup() in get_ses_refpath()

2025-02-06T03:09:07+00:00

After commit 36008fe6e3dc ("smb: client: don't try following DFS links in cifs_tree_connect()"), TCP_Server_Info::leaf_fullpath will no longer be changed, so there is no need to kstrdup() it. Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

smb: client: get rid of TCP_Server_Info::refpath_lock

2025-01-23T02:13:49+00:00

TCP_Server_Info::leaf_fullpath is allocated in cifs_get_tcp_session() and never changed afterwards, so there is no need to serialize its access. Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

smb: client: provide dns_resolve_{unc,name} helpers

2025-01-20T01:34:00+00:00

Some places pass hostnames rather than UNC paths to resolve them to ip addresses, so provide helpers to handle both cases and then stop converting hostnames to UNC paths by inserting path delimiters into them. Also kill @expiry parameter as it's not used anywhere. Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

smb: client: fix DFS mount against old servers with NTLMSSP

2025-01-20T01:34:00+00:00

Old Windows servers will return not fully qualified DFS targets by default as specified in MS-DFSC 3.2.5.5 Receiving a Root Referral Request or Link Referral Request | Servers SHOULD<30> return fully qualified DNS host names of | targets in responses to root referral requests and link referral | requests. | ... | <30> Section 3.2.5.5: By default, Windows Server 2003, Windows | Server 2008, Windows Server 2008 R2, Windows Server 2012, and | Windows Server 2012 R2 return DNS host names that are not fully | qualified for targets. Fix this by converting all NetBIOS host names from DFS targets to FQDNs and try resolving them first if DNS domain name was provided in NTLMSSP CHALLENGE_MESSAGE message from previous SMB2_SESSION_SETUP. This also prevents the client from translating the DFS target hostnames to another domain depending on the network domain search order. Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

smb: client: allow more DFS referrals to be cached

2024-11-27T00:46:15+00:00

In some DFS setups, a single DFS share may contain hundreds of DFS links and increasing the DFS cache to allow more referrals to be cached improves DFS failover as the client will likely find a cached DFS referral when reconnecting and then avoiding unnecessary remounts. Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

smb: client: Use str_yes_no() helper function

2024-11-18T04:20:54+00:00

Remove hard-coded strings by using the str_yes_no() helper function. Signed-off-by: Thorsten Blum Signed-off-by: Steve French

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