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14 commits
Author | SHA1 | Message | Date | |
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Atte Heikkilä
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dbab80e207 |
ksmbd: make utf-8 file name comparison work in __caseless_lookup()
Case-insensitive file name lookups with __caseless_lookup() use strncasecmp() for file name comparison. strncasecmp() assumes an ISO8859-1-compatible encoding, which is not the case here as UTF-8 is always used. As such, use of strncasecmp() here produces correct results only if both strings use characters in the ASCII range only. Fix this by using utf8_strncasecmp() if CONFIG_UNICODE is set. On failure or if CONFIG_UNICODE is not set, fallback to strncasecmp(). Also, as we are adding an include for `linux/unicode.h', include it in `fs/ksmbd/connection.h' as well since it should be explicit there. Signed-off-by: Atte Heikkilä <atteh.mailbox@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> |
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Al Viro
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c22180a5e2 |
ksmbd: constify struct path
... in particular, there should never be a non-const pointers to any file->f_path. Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Steve French <stfrench@microsoft.com> |
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Christian Brauner
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0c5fd887d2
|
acl: move idmapped mount fixup into vfs_{g,s}etxattr()
This cycle we added support for mounting overlayfs on top of idmapped mounts. Recently I've started looking into potential corner cases when trying to add additional tests and I noticed that reporting for POSIX ACLs is currently wrong when using idmapped layers with overlayfs mounted on top of it. I'm going to give a rather detailed explanation to both the origin of the problem and the solution. Let's assume the user creates the following directory layout and they have a rootfs /var/lib/lxc/c1/rootfs. The files in this rootfs are owned as you would expect files on your host system to be owned. For example, ~/.bashrc for your regular user would be owned by 1000:1000 and /root/.bashrc would be owned by 0:0. IOW, this is just regular boring filesystem tree on an ext4 or xfs filesystem. The user chooses to set POSIX ACLs using the setfacl binary granting the user with uid 4 read, write, and execute permissions for their .bashrc file: setfacl -m u:4:rwx /var/lib/lxc/c2/rootfs/home/ubuntu/.bashrc Now they to expose the whole rootfs to a container using an idmapped mount. So they first create: mkdir -pv /vol/contpool/{ctrover,merge,lowermap,overmap} mkdir -pv /vol/contpool/ctrover/{over,work} chown 10000000:10000000 /vol/contpool/ctrover/{over,work} The user now creates an idmapped mount for the rootfs: mount-idmapped/mount-idmapped --map-mount=b:0:10000000:65536 \ /var/lib/lxc/c2/rootfs \ /vol/contpool/lowermap This for example makes it so that /var/lib/lxc/c2/rootfs/home/ubuntu/.bashrc which is owned by uid and gid 1000 as being owned by uid and gid 10001000 at /vol/contpool/lowermap/home/ubuntu/.bashrc. Assume the user wants to expose these idmapped mounts through an overlayfs mount to a container. mount -t overlay overlay \ -o lowerdir=/vol/contpool/lowermap, \ upperdir=/vol/contpool/overmap/over, \ workdir=/vol/contpool/overmap/work \ /vol/contpool/merge The user can do this in two ways: (1) Mount overlayfs in the initial user namespace and expose it to the container. (2) Mount overlayfs on top of the idmapped mounts inside of the container's user namespace. Let's assume the user chooses the (1) option and mounts overlayfs on the host and then changes into a container which uses the idmapping 0:10000000:65536 which is the same used for the two idmapped mounts. Now the user tries to retrieve the POSIX ACLs using the getfacl command getfacl -n /vol/contpool/lowermap/home/ubuntu/.bashrc and to their surprise they see: # file: vol/contpool/merge/home/ubuntu/.bashrc # owner: 1000 # group: 1000 user::rw- user:4294967295:rwx group::r-- mask::rwx other::r-- indicating the the uid wasn't correctly translated according to the idmapped mount. The problem is how we currently translate POSIX ACLs. Let's inspect the callchain in this example: idmapped mount /vol/contpool/merge: 0:10000000:65536 caller's idmapping: 0:10000000:65536 overlayfs idmapping (ofs->creator_cred): 0:0:4k /* initial idmapping */ sys_getxattr() -> path_getxattr() -> getxattr() -> do_getxattr() |> vfs_getxattr() | -> __vfs_getxattr() | -> handler->get == ovl_posix_acl_xattr_get() | -> ovl_xattr_get() | -> vfs_getxattr() | -> __vfs_getxattr() | -> handler->get() /* lower filesystem callback */ |> posix_acl_fix_xattr_to_user() { 4 = make_kuid(&init_user_ns, 4); 4 = mapped_kuid_fs(&init_user_ns /* no idmapped mount */, 4); /* FAILURE */ -1 = from_kuid(0:10000000:65536 /* caller's idmapping */, 4); } If the user chooses to use option (2) and mounts overlayfs on top of idmapped mounts inside the container things don't look that much better: idmapped mount /vol/contpool/merge: 0:10000000:65536 caller's idmapping: 0:10000000:65536 overlayfs idmapping (ofs->creator_cred): 0:10000000:65536 sys_getxattr() -> path_getxattr() -> getxattr() -> do_getxattr() |> vfs_getxattr() | -> __vfs_getxattr() | -> handler->get == ovl_posix_acl_xattr_get() | -> ovl_xattr_get() | -> vfs_getxattr() | -> __vfs_getxattr() | -> handler->get() /* lower filesystem callback */ |> posix_acl_fix_xattr_to_user() { 4 = make_kuid(&init_user_ns, 4); 4 = mapped_kuid_fs(&init_user_ns, 4); /* FAILURE */ -1 = from_kuid(0:10000000:65536 /* caller's idmapping */, 4); } As is easily seen the problem arises because the idmapping of the lower mount isn't taken into account as all of this happens in do_gexattr(). But do_getxattr() is always called on an overlayfs mount and inode and thus cannot possible take the idmapping of the lower layers into account. This problem is similar for fscaps but there the translation happens as part of vfs_getxattr() already. Let's walk through an fscaps overlayfs callchain: setcap 'cap_net_raw+ep' /var/lib/lxc/c2/rootfs/home/ubuntu/.bashrc The expected outcome here is that we'll receive the cap_net_raw capability as we are able to map the uid associated with the fscap to 0 within our container. IOW, we want to see 0 as the result of the idmapping translations. If the user chooses option (1) we get the following callchain for fscaps: idmapped mount /vol/contpool/merge: 0:10000000:65536 caller's idmapping: 0:10000000:65536 overlayfs idmapping (ofs->creator_cred): 0:0:4k /* initial idmapping */ sys_getxattr() -> path_getxattr() -> getxattr() -> do_getxattr() -> vfs_getxattr() -> xattr_getsecurity() -> security_inode_getsecurity() ________________________________ -> cap_inode_getsecurity() | | { V | 10000000 = make_kuid(0:0:4k /* overlayfs idmapping */, 10000000); | 10000000 = mapped_kuid_fs(0:0:4k /* no idmapped mount */, 10000000); | /* Expected result is 0 and thus that we own the fscap. */ | 0 = from_kuid(0:10000000:65536 /* caller's idmapping */, 10000000); | } | -> vfs_getxattr_alloc() | -> handler->get == ovl_other_xattr_get() | -> vfs_getxattr() | -> xattr_getsecurity() | -> security_inode_getsecurity() | -> cap_inode_getsecurity() | { | 0 = make_kuid(0:0:4k /* lower s_user_ns */, 0); | 10000000 = mapped_kuid_fs(0:10000000:65536 /* idmapped mount */, 0); | 10000000 = from_kuid(0:0:4k /* overlayfs idmapping */, 10000000); | |____________________________________________________________________| } -> vfs_getxattr_alloc() -> handler->get == /* lower filesystem callback */ And if the user chooses option (2) we get: idmapped mount /vol/contpool/merge: 0:10000000:65536 caller's idmapping: 0:10000000:65536 overlayfs idmapping (ofs->creator_cred): 0:10000000:65536 sys_getxattr() -> path_getxattr() -> getxattr() -> do_getxattr() -> vfs_getxattr() -> xattr_getsecurity() -> security_inode_getsecurity() _______________________________ -> cap_inode_getsecurity() | | { V | 10000000 = make_kuid(0:10000000:65536 /* overlayfs idmapping */, 0); | 10000000 = mapped_kuid_fs(0:0:4k /* no idmapped mount */, 10000000); | /* Expected result is 0 and thus that we own the fscap. */ | 0 = from_kuid(0:10000000:65536 /* caller's idmapping */, 10000000); | } | -> vfs_getxattr_alloc() | -> handler->get == ovl_other_xattr_get() | |-> vfs_getxattr() | -> xattr_getsecurity() | -> security_inode_getsecurity() | -> cap_inode_getsecurity() | { | 0 = make_kuid(0:0:4k /* lower s_user_ns */, 0); | 10000000 = mapped_kuid_fs(0:10000000:65536 /* idmapped mount */, 0); | 0 = from_kuid(0:10000000:65536 /* overlayfs idmapping */, 10000000); | |____________________________________________________________________| } -> vfs_getxattr_alloc() -> handler->get == /* lower filesystem callback */ We can see how the translation happens correctly in those cases as the conversion happens within the vfs_getxattr() helper. For POSIX ACLs we need to do something similar. However, in contrast to fscaps we cannot apply the fix directly to the kernel internal posix acl data structure as this would alter the cached values and would also require a rework of how we currently deal with POSIX ACLs in general which almost never take the filesystem idmapping into account (the noteable exception being FUSE but even there the implementation is special) and instead retrieve the raw values based on the initial idmapping. The correct values are then generated right before returning to userspace. The fix for this is to move taking the mount's idmapping into account directly in vfs_getxattr() instead of having it be part of posix_acl_fix_xattr_to_user(). To this end we split out two small and unexported helpers posix_acl_getxattr_idmapped_mnt() and posix_acl_setxattr_idmapped_mnt(). The former to be called in vfs_getxattr() and the latter to be called in vfs_setxattr(). Let's go back to the original example. Assume the user chose option (1) and mounted overlayfs on top of idmapped mounts on the host: idmapped mount /vol/contpool/merge: 0:10000000:65536 caller's idmapping: 0:10000000:65536 overlayfs idmapping (ofs->creator_cred): 0:0:4k /* initial idmapping */ sys_getxattr() -> path_getxattr() -> getxattr() -> do_getxattr() |> vfs_getxattr() | |> __vfs_getxattr() | | -> handler->get == ovl_posix_acl_xattr_get() | | -> ovl_xattr_get() | | -> vfs_getxattr() | | |> __vfs_getxattr() | | | -> handler->get() /* lower filesystem callback */ | | |> posix_acl_getxattr_idmapped_mnt() | | { | | 4 = make_kuid(&init_user_ns, 4); | | 10000004 = mapped_kuid_fs(0:10000000:65536 /* lower idmapped mount */, 4); | | 10000004 = from_kuid(&init_user_ns, 10000004); | | |_______________________ | | } | | | | | |> posix_acl_getxattr_idmapped_mnt() | | { | | V | 10000004 = make_kuid(&init_user_ns, 10000004); | 10000004 = mapped_kuid_fs(&init_user_ns /* no idmapped mount */, 10000004); | 10000004 = from_kuid(&init_user_ns, 10000004); | } |_________________________________________________ | | | | |> posix_acl_fix_xattr_to_user() | { V 10000004 = make_kuid(0:0:4k /* init_user_ns */, 10000004); /* SUCCESS */ 4 = from_kuid(0:10000000:65536 /* caller's idmapping */, 10000004); } And similarly if the user chooses option (1) and mounted overayfs on top of idmapped mounts inside the container: idmapped mount /vol/contpool/merge: 0:10000000:65536 caller's idmapping: 0:10000000:65536 overlayfs idmapping (ofs->creator_cred): 0:10000000:65536 sys_getxattr() -> path_getxattr() -> getxattr() -> do_getxattr() |> vfs_getxattr() | |> __vfs_getxattr() | | -> handler->get == ovl_posix_acl_xattr_get() | | -> ovl_xattr_get() | | -> vfs_getxattr() | | |> __vfs_getxattr() | | | -> handler->get() /* lower filesystem callback */ | | |> posix_acl_getxattr_idmapped_mnt() | | { | | 4 = make_kuid(&init_user_ns, 4); | | 10000004 = mapped_kuid_fs(0:10000000:65536 /* lower idmapped mount */, 4); | | 10000004 = from_kuid(&init_user_ns, 10000004); | | |_______________________ | | } | | | | | |> posix_acl_getxattr_idmapped_mnt() | | { V | 10000004 = make_kuid(&init_user_ns, 10000004); | 10000004 = mapped_kuid_fs(&init_user_ns /* no idmapped mount */, 10000004); | 10000004 = from_kuid(0(&init_user_ns, 10000004); | |_________________________________________________ | } | | | |> posix_acl_fix_xattr_to_user() | { V 10000004 = make_kuid(0:0:4k /* init_user_ns */, 10000004); /* SUCCESS */ 4 = from_kuid(0:10000000:65536 /* caller's idmappings */, 10000004); } The last remaining problem we need to fix here is ovl_get_acl(). During ovl_permission() overlayfs will call: ovl_permission() -> generic_permission() -> acl_permission_check() -> check_acl() -> get_acl() -> inode->i_op->get_acl() == ovl_get_acl() > get_acl() /* on the underlying filesystem) ->inode->i_op->get_acl() == /*lower filesystem callback */ -> posix_acl_permission() passing through the get_acl request to the underlying filesystem. This will retrieve the acls stored in the lower filesystem without taking the idmapping of the underlying mount into account as this would mean altering the cached values for the lower filesystem. So we block using ACLs for now until we decided on a nice way to fix this. Note this limitation both in the documentation and in the code. The most straightforward solution would be to have ovl_get_acl() simply duplicate the ACLs, update the values according to the idmapped mount and return it to acl_permission_check() so it can be used in posix_acl_permission() forgetting them afterwards. This is a bit heavy handed but fairly straightforward otherwise. Link: https://github.com/brauner/mount-idmapped/issues/9 Link: https://lore.kernel.org/r/20220708090134.385160-2-brauner@kernel.org Cc: Seth Forshee <sforshee@digitalocean.com> Cc: Amir Goldstein <amir73il@gmail.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Aleksa Sarai <cyphar@cyphar.com> Cc: Miklos Szeredi <mszeredi@redhat.com> Cc: linux-unionfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Seth Forshee <sforshee@digitalocean.com> Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org> |
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Namjae Jeon
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04e260948a |
ksmbd: don't align last entry offset in smb2 query directory
When checking smb2 query directory packets from other servers, OutputBufferLength is different with ksmbd. Other servers add an unaligned next offset to OutputBufferLength for the last entry. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> |
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Ronnie Sahlberg
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26a2787d45 |
ksmbd: Use the SMB3_Create definitions from the shared
Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> |
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Namjae Jeon
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f7db8fd03a |
ksmbd: add validation in smb2_ioctl
Add validation for request/response buffer size check in smb2_ioctl and fsctl_copychunk() take copychunk_ioctl_req pointer and the other arguments instead of smb2_ioctl_req structure and remove an unused smb2_ioctl_req argument of fsctl_validate_negotiate_info. Cc: Tom Talpey <tom@talpey.com> Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Ralph Böhme <slow@samba.org> Cc: Steve French <smfrench@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Acked-by: Hyunchul Lee <hyc.lee@gmail.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> |
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Hyunchul Lee
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265fd1991c |
ksmbd: use LOOKUP_BENEATH to prevent the out of share access
instead of removing '..' in a given path, call kern_path with LOOKUP_BENEATH flag to prevent the out of share access. ran various test on this: smb2-cat-async smb://127.0.0.1/homes/../out_of_share smb2-cat-async smb://127.0.0.1/homes/foo/../../out_of_share smbclient //127.0.0.1/homes -c "mkdir ../foo2" smbclient //127.0.0.1/homes -c "rename bar ../bar" Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com> Cc: Ralph Boehme <slow@samba.org> Tested-by: Steve French <smfrench@gmail.com> Tested-by: Namjae Jeon <linkinjeon@kernel.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com> |
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Christian Brauner
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da1e7ada5b |
ksmbd: fix lookup on idmapped mounts
It's great that the new in-kernel ksmbd server will support idmapped mounts out of the box! However, lookup is currently broken. Lookup helpers such as lookup_one_len() call inode_permission() internally to ensure that the caller is privileged over the inode of the base dentry they are trying to lookup under. So the permission checking here is currently wrong. Linux v5.15 will gain a new lookup helper lookup_one() that does take idmappings into account. I've added it as part of my patch series to make btrfs support idmapped mounts. The new helper is in linux-next as part of David's (Sterba) btrfs for-next branch as commit c972214c133b ("namei: add mapping aware lookup helper"). I've said it before during one of my first reviews: I would very much recommend adding fstests to [1]. It already seems to have very rudimentary cifs support. There is a completely generic idmapped mount testsuite that supports idmapped mounts. [1]: https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git/ Cc: Colin Ian King <colin.king@canonical.com> Cc: Steve French <stfrench@microsoft.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: David Sterba <dsterba@suse.com> Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> |
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Hyunchul Lee
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45a64e8b08 |
ksmbd: uninterruptible wait for a file being unlocked
the wait can be canceled by SMB2_CANCEL, SMB2_CLOSE, SMB2_LOGOFF, disconnection or shutdown, we don't have to use wait_event_interruptible. And this remove the warning from Coverity: CID 1502834 (#1 of 1): Unused value (UNUSED_VALUE) returned_value: Assigning value from ksmbd_vfs_posix_lock_wait(flock) to err here, but that stored value is overwritten before it can be used. Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Steve French <stfrench@microsoft.com> |
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Hyunchul Lee
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af34983e83 |
ksmbd: add user namespace support
For user namespace support, call vfs functions with struct user_namespace got from struct path. This patch have been tested mannually as below. Create an id-mapped mount using the mount-idmapped utility (https://github.com/brauner/mount-idmapped). $ mount-idmapped --map-mount b:1003:1002:1 /home/foo <EXPORT DIR>/foo (the user, "foo" is 1003, and the user "bar" is 1002). And mount the export directory using cifs with the user, "bar". succeed to create/delete/stat/read/write files and directory in the <EXPORT DIR>/foo. But fail with a bind mount for /home/foo. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Steve French <stfrench@microsoft.com> |
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Namjae Jeon
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8b758859df |
ksmbd: reorder and document on-disk and netlink structures in headers
Reorder and document on-disk and netlink structures in headers. This is a userspace ABI to communicate data between ksmbd and user IPC daemon using netlink. This is added to track and cache user account DB and share configuration info from userspace. - KSMBD_EVENT_HEARTBEAT_REQUEST(ksmbd_heartbeat) This event is to check whether user IPC daemon is alive. If user IPC daemon is dead, ksmbd keep existing connection till disconnecting and new connection will be denied. - KSMBD_EVENT_STARTING_UP(ksmbd_startup_request) This event is to receive the information that initializes the ksmbd server from the user IPC daemon and to start the server. The global section parameters are given from smb.conf as initialization information. - KSMBD_EVENT_SHUTTING_DOWN(ksmbd_shutdown_request) This event is to shutdown ksmbd server. - KSMBD_EVENT_LOGIN_REQUEST/RESPONSE(ksmbd_login_request/response) This event is to get user account info to user IPC daemon. - KSMBD_EVENT_SHARE_CONFIG_REQUEST/RESPONSE (ksmbd_share_config_request/response) This event is to get net share configuration info. - KSMBD_EVENT_TREE_CONNECT_REQUEST/RESPONSE (ksmbd_tree_connect_request/response) This event is to get session and tree connect info. - KSMBD_EVENT_TREE_DISCONNECT_REQUEST(ksmbd_tree_disconnect_request) This event is to send tree disconnect info to user IPC daemon. - KSMBD_EVENT_LOGOUT_REQUEST(ksmbd_logout_request) This event is to send logout request to user IPC daemon. - KSMBD_EVENT_RPC_REQUEST/RESPONSE(ksmbd_rpc_command) This event is to make DCE/RPC request like srvsvc, wkssvc, lsarpc, samr to be processed in userspace. - KSMBD_EVENT_SPNEGO_AUTHEN_REQUEST/RESPONSE (ksmbd_spnego_authen_request/response) This event is to make kerberos authentication to be processed in userspace. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Steve French <stfrench@microsoft.com> |
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Namjae Jeon
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12202c0594 |
ksmbd: use ksmbd_vfs_lock_parent to get stable parent dentry
Use ksmbd_vfs_lock_parent to get stable parent dentry and remove PARENT_INODE macro. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Steve French <stfrench@microsoft.com> |
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Hyunchul Lee
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6c5e36d13e |
ksmbd: set MAY_* flags together with open flags
set MAY_* flags together with open flags and remove ksmbd_vfs_inode_permission(). Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Steve French <stfrench@microsoft.com> |
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Namjae Jeon
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1a93084b9a |
ksmbd: move fs/cifsd to fs/ksmbd
Move fs/cifsd to fs/ksmbd and rename the remaining cifsd name to ksmbd. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com> Signed-off-by: Steve French <stfrench@microsoft.com> |
Renamed from fs/cifsd/vfs.h (Browse further)