kernel/linux.git/fs/smb/client/reparse.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

cifs: Add a tracepoint to log EIO errors

2025-12-05T23:11:43+00:00

Add a tracepoint to log EIO errors and give it the capacity to convey up to two integers of information. This is then wrapped with three functions: int smb_EIO(enum smb_eio_trace trace) int smb_EIO1(enum smb_eio_trace trace, unsigned long info) int smb_EIO2(enum smb_eio_trace trace, unsigned long info, unsigned long info2) depending on how many bits of info are desired to be logged with any particular trace. The functions all return -EIO and can be used in place of -EIO. The trace argument is an enum value that gets translated to a string when the trace is printed. This makes is easier to log EIO instances when the client is under high load than turning on a printk wrapper such as cifs_dbg(). Granted, EIO could have its own separate EIO printing since EIO shouldn't happen. Signed-off-by: David Howells Reviewed-by: Paulo Alcantara (Red Hat) cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Steve French

smb: client: fix spellings in comments

2025-09-03T01:37:17+00:00

correct spellings in comments Signed-off-by: Bharath SM Acked-by: Paulo Alcantara (Red Hat) 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

cifs: Add support for creating reparse points over SMB1

2025-07-27T22:43:08+00:00

SMB1 already supports querying reparse points and detecting types of symlink, fifo, socket, block and char. This change implements the missing part - ability to create a new reparse points over SMB1. This includes everything which SMB2+ already supports: - native SMB symlinks and sockets - NFS style of special files (symlinks, fifos, sockets, char/block devs) - WSL style of special files (symlinks, fifos, sockets, char/block devs) Attaching a reparse point to an existing file or directory is done via SMB1 SMB_COM_NT_TRANSACT/NT_TRANSACT_IOCTL/FSCTL_SET_REPARSE_POINT command and implemented in a new cifs_create_reparse_inode() function. This change introduce a new callback ->create_reparse_inode() which creates a new reperse point file or directory and returns inode. For SMB1 it is provided via that new cifs_create_reparse_inode() function. Existing reparse.c code was only slightly updated to call new protocol callback ->create_reparse_inode() instead of hardcoded SMB2+ function. This make the whole reparse.c code to work with every SMB dialect. The original callback ->create_reparse_symlink() is not needed anymore as the implementation of new create_reparse_symlink() function is dialect agnostic too. So the link.c code was updated to call that function directly (and not via callback). Signed-off-by: Pali Rohár Signed-off-by: Steve French

smb: client: fix native SMB symlink traversal

2025-07-03T23:43:04+00:00

We've seen customers having shares mounted in paths like /??/C:/ or /??/UNC/foo.example.com/share in order to get their native SMB symlinks successfully followed from different mounts. After commit 12b466eb52d9 ("cifs: Fix creating and resolving absolute NT-style symlinks"), the client would then convert absolute paths from "/??/C:/" to "/mnt/c/" by default. The absolute paths would vary depending on the value of symlinkroot= mount option. Fix this by restoring old behavior of not trying to convert absolute paths by default. Only do this if symlinkroot= was _explicitly_ set. Before patch: $ mount.cifs //w22-fs0/test2 /mnt/1 -o vers=3.1.1,username=xxx,password=yyy $ ls -l /mnt/1/symlink2 lrwxr-xr-x 1 root root 15 Jun 20 14:22 /mnt/1/symlink2 -> /mnt/c/testfile $ mkdir -p /??/C:; echo foo > //??/C:/testfile $ cat /mnt/1/symlink2 cat: /mnt/1/symlink2: No such file or directory After patch: $ mount.cifs //w22-fs0/test2 /mnt/1 -o vers=3.1.1,username=xxx,password=yyy $ ls -l /mnt/1/symlink2 lrwxr-xr-x 1 root root 15 Jun 20 14:22 /mnt/1/symlink2 -> '/??/C:/testfile' $ mkdir -p /??/C:; echo foo > //??/C:/testfile $ cat /mnt/1/symlink2 foo Cc: linux-cifs@vger.kernel.org Reported-by: Pierguido Lambri Cc: David Howells Cc: Stefan Metzmacher Fixes: 12b466eb52d9 ("cifs: Fix creating and resolving absolute NT-style symlinks") Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

smb: client: fix regression with native SMB symlinks

2025-06-23T14:17:25+00:00

Some users and customers reported that their backup/copy tools started to fail when the directory being copied contained symlink targets that the client couldn't parse - even when those symlinks weren't followed. Fix this by allowing lstat(2) and readlink(2) to succeed even when the client can't resolve the symlink target, restoring old behavior. Cc: linux-cifs@vger.kernel.org Cc: stable@vger.kernel.org Reported-by: Remy Monsen Closes: https://lore.kernel.org/r/CAN+tdP7y=jqw3pBndZAGjQv0ObFq8Q=+PUDHgB36HdEz9QA6FQ@mail.gmail.com Reported-by: Pierguido Lambri Fixes: 12b466eb52d9 ("cifs: Fix creating and resolving absolute NT-style symlinks") Signed-off-by: Paulo Alcantara (Red Hat) Signed-off-by: Steve French

cifs: Remove duplicate fattr->cf_dtype assignment from wsl_to_fattr() function

2025-06-18T18:27:52+00:00

Commit 8bd25b61c5a5 ("smb: client: set correct d_type for reparse DFS/DFSR and mount point") deduplicated assignment of fattr->cf_dtype member from all places to end of the function cifs_reparse_point_to_fattr(). The only one missing place which was not deduplicated is wsl_to_fattr(). Fix it. Fixes: 8bd25b61c5a5 ("smb: client: set correct d_type for reparse DFS/DFSR and mount point") Signed-off-by: Pali Rohár Signed-off-by: Steve French

cifs: Split parse_reparse_point callback to functions: get buffer and parse buffer

2025-04-09T20:37:35+00:00

Parsing reparse point buffer is generic for all SMB versions and is already implemented by global function parse_reparse_point(). Getting reparse point buffer from the SMB response is SMB version specific, so introduce for it a new callback get_reparse_point_buffer. This functionality split is needed for followup change - getting reparse point buffer without parsing it. Signed-off-by: Pali Rohár Signed-off-by: Steve French

cifs: Improve handling of name surrogate reparse points in reparse.c

2025-04-09T20:37:26+00:00

Like previous changes for file inode.c, handle directory name surrogate reparse points generally also in reparse.c. Signed-off-by: Pali Rohár Signed-off-by: Steve French