kernel/linux.git/fs/smb/client/fs_context.h, 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

cifs: Scripted clean up fs/smb/client/fs_context.h

2026-02-08T23:07:44+00:00

Remove externs, correct argument names and reformat declarations. Signed-off-by: David Howells cc: Steve French cc: Paulo Alcantara cc: Enzo Matsumiya cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: linux-kernel@vger.kernel.org Acked-by: Enzo Matsumiya Signed-off-by: Steve French

cifs: client: enforce consistent handling of multichannel and max_channels

2025-12-04T05:32:44+00:00

Previously, the behavior of the multichannel and max_channels mount options was inconsistent and order-dependent. For example, specifying "multichannel,max_channels=1" would result in 2 channels, while "max_channels=1,multichannel" would result in 1 channel. Additionally, conflicting combinations such as "nomultichannel,max_channels=3" or "multichannel,max_channels=1" did not produce errors and could lead to unexpected channel counts. This commit introduces two new fields in smb3_fs_context to explicitly track whether multichannel and max_channels were specified during mount. The option parsing and validation logic is updated to ensure: - The outcome is no longer dependent on the order of options. - Conflicting combinations (e.g., "nomultichannel,max_channels=3" or "multichannel,max_channels=1") are detected and result in an error. - The number of channels created is consistent with the specified options. This improves the reliability and predictability of mount option handling for SMB3 multichannel support. Reviewed-by: Shyam Prasad N Signed-off-by: Rajasi Mandal Signed-off-by: Steve French

smb: client: set symlink type as native for POSIX mounts

2025-08-01T05:16:19+00:00

SMB3.1.1 POSIX mounts require symlinks to be created natively with IO_REPARSE_TAG_SYMLINK reparse point. Cc: linux-cifs@vger.kernel.org Cc: Ralph Boehme Cc: David Howells Cc: Reported-by: Matthew Richardson Closes: https://marc.info/?i=1124e7cd-6a46-40a6-9f44-b7664a66654b@ed.ac.uk Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

smb: client: ensure aligned IO sizes

2025-05-01T13:35:58+00:00

Make all IO sizes multiple of PAGE_SIZE, either negotiated by the server or passed through rsize, wsize and bsize mount options, to prevent from breaking DIO reads and writes against servers that enforce alignment as specified in MS-FSA 2.1.5.3 and 2.1.5.4. Cc: linux-cifs@vger.kernel.org Reviewed-by: David Howells Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

cifs: Allow to disable or force initialization of NetBIOS session

2025-04-01T06:54:17+00:00

Currently SMB client always tries to initialize NetBIOS session when the server port is 139. This is useful for default cases, but nowadays when using non-standard routing or testing between VMs, it is common that servers are listening on non-standard ports. So add a new mount option -o nbsessinit and -o nonbsessinit which either forces initialization or disables initialization regardless of server port number. This allows Linux SMB client to connect to older SMB1 server listening on non-standard port, which requires initialization of NetBIOS session, by using additional mount options -o port= and -o nbsessinit. Signed-off-by: Pali Rohár Signed-off-by: Steve French

smb: client: Store original IO parameters and prevent zero IO sizes

2025-04-01T02:12:31+00:00

During mount option processing and negotiation with the server, the original user-specified rsize/wsize values were being modified directly. This makes it impossible to recover these values after a connection reset, leading to potential degraded performance after reconnection. The other problem is that When negotiating read and write sizes, there are cases where the negotiated values might calculate to zero, especially during reconnection when server->max_read or server->max_write might be reset. In general, these values come from the negotiation response. According to MS-SMB2 specification, these values should be at least 65536 bytes. This patch improves IO parameter handling: 1. Adds vol_rsize and vol_wsize fields to store the original user-specified values separately from the negotiated values 2. Uses got_rsize/got_wsize flags to determine if values were user-specified rather than checking for non-zero values, which is more reliable 3. Adds a prevent_zero_iosize() helper function to ensure IO sizes are never negotiated down to zero, which could happen in edge cases like when server->max_read/write is zero The changes make the CIFS client more resilient to unusual server responses and reconnection scenarios, preventing potential failures when IO sizes are calculated to be zero. Signed-off-by: Wang Zhaolong Signed-off-by: Steve French

cifs: Add new mount option -o nounicode to disable SMB1 UNICODE mode

2025-03-26T19:51:58+00:00

SMB1 protocol supports non-UNICODE (8-bit OEM character set) and UNICODE (UTF-16) modes. Linux SMB1 client implements both of them but currently does not allow to choose non-UNICODE mode when SMB1 server announce UNICODE mode support. This change adds a new mount option -o nounicode to disable UNICODE mode and force usage of non-UNICODE (8-bit OEM character set) mode. This allows to test non-UNICODE implementation of Linux SMB1 client against any SMB1 server, including modern and recent Windows SMB1 server. Signed-off-by: Pali Rohár Signed-off-by: Steve French

cifs: Add support for creating native Windows sockets

2025-01-31T18:51:20+00:00

Native Windows sockets created by WinSock on Windows 10 April 2018 Update (version 1803) or Windows Server 2019 (version 1809) or later versions is reparse point with IO_REPARSE_TAG_AF_UNIX tag, with empty reparse point data buffer and without any EAs. Create AF_UNIX sockets in this native format if -o nonativesocket was not specified. This change makes AF_UNIX sockets created by Linux CIFS client compatible with AF_UNIX sockets created by Windows applications on NTFS volumes. Signed-off-by: Pali Rohár Signed-off-by: Steve French

cifs: Add mount option -o reparse=none

2025-01-29T23:35:38+00:00

This new mount option allows to completely disable creating new reparse points. When -o sfu or -o mfsymlinks or -o symlink= is not specified then creating any special file (fifo, socket, symlink, block and char) will fail with -EOPNOTSUPP error. Signed-off-by: Pali Rohár Signed-off-by: Steve French